1. Introduction
Controlling the cost of production at optimum level is one of the essential
requirements for the spinning mills to compete successfully in the market. Hence,
mills are expected to initiate suitable measures such as profitable product-mix, higher
productivity, modernisation of machinery and cost control to improve profitability.
SITRA has been offering consultancy services to mills to reduce input costs without
any major investment. After a thorough study, the findings highlighting the expected
savings in various areas such as waste reduction, improvement in labour and machine
productivity and reduction in packing materials cost are submitted to the mills.
Five years ago, SITRA brought out a Focus (Vol.20, No.3, September 2002)
on case study of a spinning mill, in which suggestions were offered to reduce the
input cost. The present Focus covers the case study of another spinning mill, in which
measures for cost reduction have been offered.
2. Profile of the mill
It is a 20 years old unit with an installed capacity of 36000 spindles and 1380
rotors. The mill is equipped with hi-tech machinery in all the departments. It has
been producing 100% viscose, 100% polyester and polyester/ viscose blended yarns.
3. Areas identified for cost reduction
The summary of the mill’s performance and suggestions for cost reduction are
given in the following pages.
Please Click for full Report'
Saturday, June 6, 2009
Recent developments in the field of texturing technologies
Texturing process applied to impart additional value and quality to synthetic filament yarns creates crimps, curls and loops and like features that natural fibres possess by nature, says Prof Dr Ali Demir
Texturing process as applied to most of the filament yarns are today well accepted by the textile industry. The following technologies are the majors techniques for the purpose of texturing:
- False-twist texturing
- Texturing by a cold air-jet
- Texturing by a hot air-jet and a stuffer box
- Other marginal techniques.
There have been many developments in the above mentioned technologies during the last decade when the demand for synthetic filament yarns have especially increased. These developments may be grouped in the following areas: higher texturing speeds for better economics, quality monitoring and control systems for better quality, and systems for the production of fancy textured yarns.
This paper will present the details of these developments and also introduce the most recent crimp formation techniques entitled 'self-crimped filament yarn spinning'. It is believed that these recent techniques will have a tremendous potential for the future.
Texturing-technology basics
The purpose of texturing is to impart permanent crimps, curls and/or loops to flat filaments in order to improve the use of these monotonous one-dimensional structures. Depending on the material of the filament, texturing is achieved by thermo-mechanical as well as pure-mechanical techniques. The false-twist texturing and BCF technologies dominate the thermo-mechanical techniques whereas the air-jet texturing solely represent the pure-mechanical texturing.
False-twist texturing technology
The helicular, i.e., three-dimensional, crimps are created by the simultaneous effects of false-twisting and heat-setting. As soon as the twisted structure is untwisted by the nature of false-twisting effect, the filaments obtain the crimped geometry. At the current state of development, the false-twist texturing is achieved at around 800-1200 m/min (depending on the polymer and yarn count) using POY as feed material which is also drawn simultaneously. The process economics have, for long, been requiring the integration of the spinning and texturing processes. The first ever prototype of this approach was on display.
- Integration of the false-twist texturing with spinning
The Swiss company RETECH has been working on the development of a false-twist texturing using rotating heated cylinders instead of conventional texturing heater. They have developed and marketed a machine, named as TEX2000, which is claimed to run at 2000 m/min. With the encouragement of this technology, Retech has extended the application area of this machine to the integration with POY spinning process. Working with a Italian POY spinning equipment manufacturer, certain integration seemed to have been achieved. The process is currently successful, on PP spin-draw-texturing due to much forgiving nature of PP polymer.
- Fancy effects created by the false-twist texturing
Despite the fact that, the false-twist texturing creates crimps to impart natural feel and stretch to synthetic filament yarns, it lacs natural appearance due to monotonous geometry. In order to break up this monotonous look, certain effects are imparted to the false-twist textured yarns during the process by the following techniques:
- Hot pin for colour variation
The major portion of drawing is done on an additional draw zone equipped with a hot-pin or hot-shoe before the texturing process. Since the hot-pin imparts irregular and repetitive action on the filaments, the textured yarn obtains light and dark coloured sections when dyed. By varying the draw ratio, hot-pin temperature as well as the yarn speed, various affects are created. Especialy at low yarn speeds such as 200 m/min, the effecs are so pleasant that the textured yarn gets a high value in the market.
- Thick-and-thin yarn
When the draw ratio is reduced to its lowest possible level whilst the twist insertion, D/Y ratio, rate is increased to its maximum possible level, the textured yarn gets a continuous state of surging where yarn obtains thick and thin places all over the yarn. Despite the fact that, this effect is not a permanent feature, it stays on the yarn under the tensions applied in weaving. Therefore, the woven fabric achieves a linen-like appearance.
- Elastan covering during texturing
The modern fashion life requires the lightest possible garment with freedom of movement. This two contradicting requirements are best compromised by the stretch garments be it underwear, swimwear or outerwear. The traditional textile fibres do not have the necessary stretching power. Yet, the modern polymeric fibre elastan offers this flexibility with one small drawback. That is the biting effect on bare skin. Due to this peculiar effect, the elastan fibres have to be covered with traditional fibres. The covering may be achieved before or during fabric formation. The twist covering is very well known due to its huge costs emanating from the high twist requirement.
The economical alternative has been developed as air-jet covering using the intermingling process. Nevertheless, increasing economical pressures as well as improved intermingling jets, it is now possible to integrate the elastan covering during the texturing operation.
With the addition of elastan feeding equipment to the texturing machines, it is becoming a standard feature especially for PA texturing operation where PA is widely used to cover the elastan for all purposes ranging from ladies hosiery to ladies suitings. Moreover, PET textured yarn is also widely used to cover elastan for mens' stretch suiting as well as home textiles for excellent drape properties of elastan covered yarns.
Bulked continuous filament (BDF) technology
The traditional area of application for the BCF yarns is the floor covering. However, the current developments resulting in higher speeds and lower yarn counts, tend to make these yarns to be employed in the traditional textile uses such as upholstery as well as outerwear. Despite the usual filament dpf of 10-15 denier for the BCF yarns, the recently developed BCF texturing jets are able to handle fine filaments as low as 3-5 denier. The completed spin-draw-texturing is fully achieved with the BCF process. Nevertheless, it is only limited to PA and PP polymers as PET requires more time for necessary heat transfer to the core of the filaments. Today, PA6 or PA6.6 filament BCF yarns at 600 dtex are produced at 3500 m/min winding speeds. Due to the inherent low molecular weight and adverse molecular weight distribution, the PP BCF yarns at 900 dtex can only be produced at 3000 m/min.
Air-jet texturing technology
In comparison with the false-twist texturing or BCF yarn production, the process speeds of air-jet texturing is still regarded as low speed at 500-600 m/min levels. However, the development efforts of Heberlein, the pioneering jet developer for the air-jet texturing process, have been constantly focused on higher process speeds. The latest developed jets have been claimed to process at 800 m/min with 150 dtex yarns. Since the wetting of filaments before they are ed into the texturing jets is an inevitable process requirement, it entails the washing off the spin finish and hence blockage of yarn path with spin finish residues. Especially extreme working conditions such as cold/hot ambient, higher speeds as well as long process runs, this poses an immense quality assurance problems. In order to avoid such surprises, Heberlein has developed a novel jet that rotates during the process. The rotating action of the jet creates a self cleaning action for longer runs.
Future trends
Due to tremendous economical as well as ecological (low or no noise emission) advantages, it is firmly believed that the future developments will be focused around the creating texturing effect by means of self-crimping. However, for some in the near future, the conventional texturing technologies will further be developed for better economics, higher process speeds and fancy texturing effects, and for better quality, on-line quality monitoring sensors and systems.
(The author is with Istanbul Technical University, Department of Textile Engineering, 80190-Gumussuyu-Taksim-Istanbul, Turkey)
Thanks to
CORE YARNS AND PRECAUTIONS NEEDED TO SPUN CORE YARNS
This Interesting Article found at www.lrtindia.com from its various readers. I give collectively. The Credit goes to www.lrtindia.com and textile point appreciates their efforts in helping the global textile community.
Mr.S.Sundaravadivel, Vice President, Pallava Textiles Pvt. Limited, Sangagiri, Tamilnadu
Core Yarn: It is a Compound structure consisting of a core surrounded by a fiber, which is suitable to use as a yarn. The core may be rigid or elastic.
Precautions:
1. Selection of superior core spun yarn attachment is more important.
2. Uniform & high quality roving should be used for core spun yarn process.
3. Accurate adjustments of rings and travellers to make better package of cop without forming steps.
4. Good lighting is necessary for easy detection of filament breakage.
5. Excellent cleaning devices to prevent fly deposits.
6. Conditions of cots, aprons and drafting rollers should be strictly maintained.
7. Accurate centering of revolving guides will avoid friction, creating micro breaks.
8. Well trained and motivated operators should be engaged for perfect handling of filament package and yarn piecing, gaiting in spinning.
9. Careful handling & storing of filament material is very important to prevent damages
10. Department temperature and humidity should be strictly maintained at the optimum level.
11. Perfect alignment with roving, higher level of twist, heavier weight travellers are required to avoid core exposure.
12. Proper yarn number calculation and core content determining method should be properly adopted
——————————————————————————————————————————————————————————————
Mr.Sankarabagam, Mill Manager, Pariyur Amman Spinning Mill Limited, Gobichettipalayam, Tamilnadu
Core Yarn: This is nothing but Cotton or Polyester yarn blended with filament yarn in ring frame called as Core Yarn.
Precautions:
While producing core yarn polyester / Cotton yarn will be drafted and filament should be processed through front Roller region.
For good blended, we should provide guide in between cradle and front top roller.
Proper piecing method should be implemented in spinning to avoid improper core yarn.
Traverse motion should not be utilised for producing good core yarn.
Precaution should to be taken for keeping the drafting zone clean. Cots, apron condition, should be fluff and fly free.
Buffing should be done for every 30 days for producing Good yarn.
Traveller should be changed once in week. Special creel attachment should to be provided for creeling Filament yarn.
——————————————————————————————————————————————————————————————
Mr.V.Balasundaram, General Manager, Vijayeswari Textiles Limited, Pollachi.
Core Yarn: The yarn spun by wrapping the fibres on to a continuous filament is called core yarn. The two types of core yarn are Hard core with core as higher in percentage and it is used in sewing applications and special fabrics (example - Poly core, Poly cotton core, Nylon core, etc., and Fire retardant Kevlar core and Cupro cotton & Silk cotton core for fabrics). The second type is the soft core where the core % is lower and it is used to improve the yarn elasticity, finds its application in various types of fabrics (example - Lycra).
Precautions:
Both these types of core need special care while spinning. One should ensure that proper creel and feeding arrangement is provided with stop motion for soft core. In case of hard core stop motion is not mandatory as it can be easily picked up when core/cover is missing. Optimum unwinding tension of core filament is to be ensured for quality core yarns. Another major factor influencing the quality is the selection of traveller. It is essential that round cross section travellers are selected in order to ascertain that the cover is not disturbed (peeling off). Yarn balloon is to be closely monitored to ensure that it does not touch any parts like separators, empties and gets disturbed. Spindle speeds must be reduced to an extent that breakages are maintained well below 10/1000 spindle hour. Special Training to workers highlighting probable reasons detrimental to quality is a must.
——————————————————————————————————————————————————————————————
Mr.S.K. Jindal, General Manager (Spinning), Ginni International Limited, Neemrana, Rajasthan
Core yarn: A yarn in which, one type of fibre is twisted or wrapped around another that serves as a core yarn.
Precautions:
1. Core filament should be totally covered with surrounding sheath fibers & should be at center.
2. Core filament should not be missing at any place in the yarn to provide necessary stop motions for the same
3. Yarn splice quality should be good.
4. Yarn should not get opened during its use
——————————————————————————————————————————————————————————————
Mr.P.Marimuthu, Manager – Quality Assurance, Sri Gomathy Mills Pvt Limited, Viravanallur
Core Yarn: One Extra yarn wrapped around main yarn thereby improving yarn elasticity
characteristics, the extra wrapper is inserted at drafting zone with an additional attachment is
called Core Yarn. Examples: Cotton & Lycra
Precautions:
1. Spindle speed should be reduced when compared to normal spinning
2. Increase and improve the illumination to 120 LUX
3. Engage one sider for 1000 spindles
4. Breakage rate should be below 1%
5. Cops should be taken out from ends down spindles and keep the cops separately
and remove the yarn till the core yarn comes to spring action, which is the
indication for Lycra content.
6. Inspection with bright lighting is needed to check Lycra path.
7. Set CA, CCA Setting in Autoconer as 6% to ensure Lycra missing
8. Piecing hands and fingers should be free from dirt and oil
9. Drafting zone and yarn should be cleaned well to maintain the yarn quality.
Mr.S.Sundaravadivel, Vice President, Pallava Textiles Pvt. Limited, Sangagiri, Tamilnadu
Core Yarn: It is a Compound structure consisting of a core surrounded by a fiber, which is suitable to use as a yarn. The core may be rigid or elastic.
Precautions:
1. Selection of superior core spun yarn attachment is more important.
2. Uniform & high quality roving should be used for core spun yarn process.
3. Accurate adjustments of rings and travellers to make better package of cop without forming steps.
4. Good lighting is necessary for easy detection of filament breakage.
5. Excellent cleaning devices to prevent fly deposits.
6. Conditions of cots, aprons and drafting rollers should be strictly maintained.
7. Accurate centering of revolving guides will avoid friction, creating micro breaks.
8. Well trained and motivated operators should be engaged for perfect handling of filament package and yarn piecing, gaiting in spinning.
9. Careful handling & storing of filament material is very important to prevent damages
10. Department temperature and humidity should be strictly maintained at the optimum level.
11. Perfect alignment with roving, higher level of twist, heavier weight travellers are required to avoid core exposure.
12. Proper yarn number calculation and core content determining method should be properly adopted
——————————————————————————————————————————————————————————————
Mr.Sankarabagam, Mill Manager, Pariyur Amman Spinning Mill Limited, Gobichettipalayam, Tamilnadu
Core Yarn: This is nothing but Cotton or Polyester yarn blended with filament yarn in ring frame called as Core Yarn.
Precautions:
While producing core yarn polyester / Cotton yarn will be drafted and filament should be processed through front Roller region.
For good blended, we should provide guide in between cradle and front top roller.
Proper piecing method should be implemented in spinning to avoid improper core yarn.
Traverse motion should not be utilised for producing good core yarn.
Precaution should to be taken for keeping the drafting zone clean. Cots, apron condition, should be fluff and fly free.
Buffing should be done for every 30 days for producing Good yarn.
Traveller should be changed once in week. Special creel attachment should to be provided for creeling Filament yarn.
——————————————————————————————————————————————————————————————
Mr.V.Balasundaram, General Manager, Vijayeswari Textiles Limited, Pollachi.
Core Yarn: The yarn spun by wrapping the fibres on to a continuous filament is called core yarn. The two types of core yarn are Hard core with core as higher in percentage and it is used in sewing applications and special fabrics (example - Poly core, Poly cotton core, Nylon core, etc., and Fire retardant Kevlar core and Cupro cotton & Silk cotton core for fabrics). The second type is the soft core where the core % is lower and it is used to improve the yarn elasticity, finds its application in various types of fabrics (example - Lycra).
Precautions:
Both these types of core need special care while spinning. One should ensure that proper creel and feeding arrangement is provided with stop motion for soft core. In case of hard core stop motion is not mandatory as it can be easily picked up when core/cover is missing. Optimum unwinding tension of core filament is to be ensured for quality core yarns. Another major factor influencing the quality is the selection of traveller. It is essential that round cross section travellers are selected in order to ascertain that the cover is not disturbed (peeling off). Yarn balloon is to be closely monitored to ensure that it does not touch any parts like separators, empties and gets disturbed. Spindle speeds must be reduced to an extent that breakages are maintained well below 10/1000 spindle hour. Special Training to workers highlighting probable reasons detrimental to quality is a must.
——————————————————————————————————————————————————————————————
Mr.S.K. Jindal, General Manager (Spinning), Ginni International Limited, Neemrana, Rajasthan
Core yarn: A yarn in which, one type of fibre is twisted or wrapped around another that serves as a core yarn.
Precautions:
1. Core filament should be totally covered with surrounding sheath fibers & should be at center.
2. Core filament should not be missing at any place in the yarn to provide necessary stop motions for the same
3. Yarn splice quality should be good.
4. Yarn should not get opened during its use
——————————————————————————————————————————————————————————————
Mr.P.Marimuthu, Manager – Quality Assurance, Sri Gomathy Mills Pvt Limited, Viravanallur
Core Yarn: One Extra yarn wrapped around main yarn thereby improving yarn elasticity
characteristics, the extra wrapper is inserted at drafting zone with an additional attachment is
called Core Yarn. Examples: Cotton & Lycra
Precautions:
1. Spindle speed should be reduced when compared to normal spinning
2. Increase and improve the illumination to 120 LUX
3. Engage one sider for 1000 spindles
4. Breakage rate should be below 1%
5. Cops should be taken out from ends down spindles and keep the cops separately
and remove the yarn till the core yarn comes to spring action, which is the
indication for Lycra content.
6. Inspection with bright lighting is needed to check Lycra path.
7. Set CA, CCA Setting in Autoconer as 6% to ensure Lycra missing
8. Piecing hands and fingers should be free from dirt and oil
9. Drafting zone and yarn should be cleaned well to maintain the yarn quality.
Spinning : Higher End Breaks in Cop Bottom - www.lrtindia.com
This Interesting Article found at www.lrtindia.com from its various readers. I give collectively. The Credit goes to www.lrtindia.com and textile point appreciates their efforts in helping the global textile community.
Question: Explain the reasons for higher end breakage in cop bottom stage in
spinning? What are remedies to control the same?
******
Mr.Ayub Khan, Naheed Composite Textiles, Dhaka, Bangladesh
Following are the some points for higher breakage arte in cop bottom stage:
1. Improper selection of ring Travellers, e.g., Traveller weight, height and cross section
2. Improper setting of lappet height and abc ring height
3. The spindle speed grasp is not properly set
4. Variation in ring & spindle centering
5. Improper selection of TM in the count
6. Improper selection of spacer & top arm pressure
7. Cop build at bottom is not properly setting
8. Worn-out separators
9. Chase length is not properly set as per ring diameter
10. The diameter of bobbin should be always min 2.5 MM lesser than ring diameter
11. Improper selection of ring diameter vs. lift & count spun
12. Improper humidity and temperature.
With the above points, we can reduce breakage at cop bottom stage.
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Mr.Desu Purnachandra Rao, FM, Kallam Brothers Cottons Pvt Ltd. Guntur, Andrapradesh
The main reason for more end breaks at cop bottom is the angle of pull is very height and the
balloon size is more that means the yarn from the front roller to cop bottom is more. So we have to
handle the more length of yarn. The breaking of long thread is very easy than the shorter length
threads. The weak place / thin place / contamination of jute or hair will cause to break in this stage
is height. The following were the some of the tips to minimize the end breaks.
1. If the balloon size is more or less it should not touch the tip of the cop.
2. To control the large balloon we need the heavier traveller at this stage if we maintain the same
speed. So that instead of traveller we are reducing the spindle speed at this cop bottom stage.
3. The contact of ring traveller is more at this stage. We have to observe the traveller fly. If it
found more, we have to go for heavier.
4. The ring rail / ring should perfectly 90 deg to spindle “x “and “y “axis. Normally the spindle gauge
will take place at the ¾ stage of cop. It is advisable to check at cop bottom also.
5. We can observe the more cop bottom breaks at the end of traveller life.
6. Ring dia vs. empty cop bottom dia will also play the more end breaks. E.g. a) The ring dia 40 mm,
empty cop dia at bottom is 20 mm. B) the ring dia 38mm, empty cop dia at bottom is 20 mm. We can
observe lesser end breaks at cop bottom in sample “b”.
7. The spindle speed to be increase slowly at cop bottom stage also help to reduce the end breaks
less at cop bottom.
8. The traveller loading also will effect more ends breaks at cop bottom.
9. More rh % and fluff level also effect the end breaks more at cop bottom.
10. More trash and kitties in yarn also affect the end breaks more at cop bottom.
11. The selection of traveller profile i.e. the clearance for yarn path to be more for more ipi yarn.
----------------------------------------------------------------------------------------------------------
Mr.P.Sakthivel, Spinning Master, Mani Spinning Mills, Vedasandur, Tamilnadu
Reason: The strain on the yarn is maximum level at the bottom of the ring rail position; secondly
the Traveller has to make more rotation to lay the delivered yarn on the empty cop immediately
after doffing. As the cop builds up the rotation of Traveller educes and there by reduction in yarn
tension. These two factors are causing more end breaks at the bottom of the cop position.
Remedies:
1. Selecting the lower spindle speed of 50 to 60% to that of highest spindle speed in the full
doff speed cycle and depending upon the single yarn strength
2. Selecting lesser rind diameter
3. Selecting the ratio of tube length and ring diameter to be 5:1.
4. Setting the lappet hook distance from top of the tube to be two times of top portion
diameter of ring tube.
5. Selecting higher wall thickness ring tubes
6. Selecting lighter Traveller with smooth surface finish
7. Setting Traveller clearer to be 0.25MM to Traveller.
8. Keeping ABC Rings, rings, spindles and lappet eye concentric.
9. Selecting ring tubes with no eccentric running.
10. Selecting optimum spindle triangle.
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Engr. Hasan (Kazi Hasanul Karim), Asst. Manager – Maintenance, Akij Textile Mills Ltd. Manikgonj,
Bangladesh.
Reasons for end breakage in cop bottom stage in spinning:
1. Not proper under winding
2. Speed not synchronies with count-ring traveller-cops dia-full bobbin dia etc
3. Pre twist not proper
4. Top or bottom bunch not proper
5. Doffing time yarn not stays in ring traveller.
Remedies:
1. Proper settings of speed pattern-pre twist-under winding-etc.
2. ,Doffing should be done such way that yarn not breakage and out from ring traveller,
3. Under winding place should be clean ( remove waste yarns)
At last we can say that, if we want to reduce end breakage we must to ensure the tension and twist
whole that cop should same of considerable.
----------------------------------------------------------------------------------------------------------
Mr.V.Duraiswamy, General Manager. JG Spinning Mills Pvt Ltd., Annur, Tamilnadu
Improper selection of Traveller number, Lighter Traveller will give excessive balloon and created
breaks, excessive height of Ring tubes (25 to 35mm) above spindle tip, also worn-out or scratch
Ring tube tip will give higher brakeage. Wrong setting or selection of spindle speed at cop bottom
will create higher yarn tension and breaks.
Remedies to control the cop bottom breaks
Right Traveller number should be used such that, yarn ball on should not touch separators as well as
Ring tube tip. It can be observed by using 1 No. heavier and 1 No. lighter Traveller than normal
Traveller number side by side for few spindles and decide the correct yarn tension and right
Traveller Number.
The spindle speed of Ring frame should be set 30 to 40% lower than the Maximum spindle speed
till cop reach 30% of content. The Ring tube height should be 10mm to 15mm than spindle lift.
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Mr.Sudhakar Kodela, Technical director, Spincot Textiles Pvt. Ltd., Guntur, Andrapradesh
Generally Yarn break occurs when current spinning tension in the spinning process at cop bottom is
higher than the current yarn strength. The following are the reasons for high incidence of breaks
at cop bottom.
Problem Reason Remedial measure
1. Balloon size high - Low traveler weight Increase traveler weight
2. Balloon touching
Separators - Low traveler weight Increase traveler weight and
3. Damaged separators - holed, cuts on separators Replace with new the separators.
4.Improper ABC ring dia - Recommended dia is
ring dia+2 mm Replace with rec.size of ABC ring.
5. Improper distance of - 2/3 of the distance of Check the distance and adjust
ABC ring fixation ring rail is suggested accordingly.
6. Bend/scratched - It obstructs the free flow Replace with new ABC ring.
Balloon ring of yarn and increase
yarn tension.
7. Fixing ‘S’twist ABC - The yarn flow will not be Replace with ‘Z’ or Universal
Rings in ‘Z’ twist m/c. be free. ABC ring.
8. Balloon touching the - traveler is heavy try with lighter traveler.
Tip of the bobbin.
9. Balloon touching the improper lappet gauge. Adjust the lappet gauge.
one side of the bobbin.
10. Collapsing balloon Improper size/profile of try with correct profile/size of
Traveller. The traveller.
11.Improper setting of Increases yarn tension. Correct the thread guide setting.
thread guide.
12.Physical damage to obstructs yarn flow replace with new thread guide.
thread guide.
13.Orifice of the thread - creates improper balloon. Smaller for fine count(1.8-2.2mm).
guide. 2.5-3.0 mm for other counts.
14.Thread guide distance - creates improper balloon optimize as per machinery
To empty tube. Manufacture recommendations.
15.Tube length is more - Lower tube length/lower Optimize the tube length as
Lift reduces tension. Per the lift of the machine.
16.Damaged ring tubes - obstructs yarn flow Remove such tubes by
periodical inspection.
17.concentricity of tubes increases yarn tension use tubes with better
Dimensional stability.
18.improper ring centering - increases yarn tension correct centering.
19.bend spindle plug - rotates eccentrically replace the spindle.
20.Improper locking of - wear & tear at button replace the empties.
Tubes on spindle. area.More slippage occurs.
21.Ratio of ring/tube - ideal is 1:5 Use suitable ring tube
length ring &tube dia 2:1 length and dia of tube.
22.Ring condition - bad ring will not allow replace the ring.
yarn to run.
23. Accumulation of - traveller will not freely wipe with dry cloth.
micro dust on ring
surface.
24.Traveller too light - poor twist contraction of fibres try with increased
Heavy friction of the balloon on traveller weight.
Anti ballooning ring.
25.Traveller too heavy - increase yarn tension/ reduce traveller wt.
Too low balloon.
26.worn out traveler - obstructs free rotation of adjust the traveller
traveller change schedule.
27.High spindle speed - increases yarn tension optimize the spindle
At bottom speed at bottom.
28. Clearance between - fibres protruding from the optimize clearance.
Cop and ring cop will be catched by traveler.
29.Too low centre to - air turbulance will carry fibres to while planning the project
Centre distance adjascent ring frame and effects sufficient space is to be
between ring frames. the working at bottom. left/ or to reduce the
spindle speed.
30.too much rolling fluff - improper grills of exhaust. To modify and provide
on the floor. Sufficient no. of grills.
31.yarn unthreading from - yarn comes out of the traveler change traveler type/
traveller when RF restarted after doff. profile.
32.over cop bottom - yarn touches the ring reduce the cop bottom
33.Improper short snarl - due to snarls more breaks occur adjust delay draft setting.
Removal. at the bottom after restart.
34.Traveller flying at - Improper size/type of traveler. Choose low bow height
Bottom traveler/try with other type.
35.Traveller clearer setting - fluff accumulates on traveler adjust clear setting.
36.type of traveler cleaner - tangential type is suitable for check for type suitability
High spindle speeds.
----------------------------------------------------------------------------------------------------------
Mr. Sarba Narayan Sen, Maintenance Manager, Jalal Ahmed Spinning Mills Ltd., Narayanganj,
Bangladesh
The Mechanics of higher end breakage in Cop Bottom stage lies mainly on the geometry of yarn
passage from the Front Roller nip to the Ring Bobbin through the lappet eye and the Ring Traveller.
The usual system of slow start with smooth increase of spindle speed is a good choice. Higher
Spinning Angle at the start also contributes greatly to achieve the desired result. Rising and falling
lappet is a good solution. To increase the Angle of Wrap, sharply tapered bobbin at the bottom up
to ¼th of the lift can be opted. Suitable choice of Cop Builder for low chase length at bottom will
increase the Angle of Wrap at a faster rate. Proper selection of Ring Traveller is also of prime
importance. Finally, well polished and proper size hole diameter of the lappet eye for even
distribution of twist flow and smooth passage of yarn respectively will certainly ensure the
breakage rate at the cop bottom to minimum.
------------------------------------------------------------------------------------------------------------------------------------------------
Mr.K.Murali, Production Manager, Rohini Textile Industries Ltd., Sathyamangalam, Tamilnadu
In ring spinning generally all spinners are aiming for best possible production and productivity
through minimizing the end breakage rate which in turn is governed by yarn balloon tension. As the
yarn balloon size and shape vary from cop bottom to cop full size the yarn tension could not be
uniform through the cop bottom to cop full size. For the given yarn count the initial yarn balloon
tension gradually reduces with respect the ring rail upward movement.
Thus the balloon tension level of yarn exhibits maximum during cop bottom and cop initial stages.
Of course the spindle speed, traveler weight, angle of yarn pull, spinning triangle and spinning
geometry are also criteria for end breakage rate higher at cop bottom stage.
Hence the cop bottom stage breakage is mainly due to higher yarn balloon tension. For intensified
analysis of yarn tension cop build up package can be divided in to two stages
STAGE I: Upto cop package taper formation
STAGE II after cop package taper formation
In stage I the tension imposed on yarn comparatively higher than stage II. Because of the
following reasons.
· Higher balloon size and balloon weight.
· Angle of yarn pull remains low and remains almost constant in stage I
· Whereas in stage II cop package dia increases , angle of yarn pull also increases and inertly
variable within chase length causing smooth gliding of traveler resulting lower tension on
yarn and reduces end breakage rate.
· Twist free flow to the front roller nip, higher length of spinning yarn i.e. from front fluted
roller nip to traveler reduces twist free flow which causing spinning triangle at nip stitch
possibilities, in turn causing end breakage in yarn. This will be more at cop bottom stages.
REMEDIES
Faultless condition of support and guide of the ring rail as well as steady traverse motion.
Concentric position of ring and spindle as well as anti ballooning ring and yarn guide.
Spindle rotation without vibration and correct concentricity of bobbin tube.
Ring with exact roundness and firm seating in horizontal position.
Correct setting of traveler clearer ( 0.2 to 0.3 mm )
Favorable ring dia to tube dia ratio 2 : 1
Favorable ring dia to tube length ratio 1 : 5
Proper position of lappet height from bobbin tube tip 2D + 5 mm of tube dia
Good combination of ring and traveler profile , which should not either less area of contact
of ring to traveler or less yarn passage space .( less Horn – Play )
Do right selection of correct type of traveler and correct number (traveler weight) with
respect to the count to be spun, material, ring dia, spindle speed, yarn strength and life of
ring.
Keeping lesser spindle speed in bottom stage and higher speed in after bottom stage to
narrow down the yarn tension difference. This may be tuned with the feed back report of
full doff end breakage rate study.
Disc type pulley and variator belt provision for step less spindle speed control with
computerized programmed spindle speed table.
Minimum ring dia adoption ( 36 mm , 38 mm ) with 1 : 40 ,1:64 taper ratio .
Adoption of anti balloon control rings , lesser dia lappet hooks.
Selection of short stitch spinning geometry. (18deg,24deg3mts)minimum and maximum
degree of angle covered by the line of front roll nip to lappet eye to the axis line of spindle.
Replacement of worn out rings , up keeping of builder motion mechanical component .
Fine tuning of traveler weight taking in to the account of end breakage study feed back.
--------------------------------------------------------------------------------------------------------
Mr.Sudip Nandy ,General Manager (production), DCM Textiles, Hissar, Haryana
Tensile force / yarn tension exerted on yarn must be much higher during winding on the bare tube
than during winding on the full cop, because of the difference in the angle of attack of the yarn on
the traveller.
Yarn tension in the balloon is the tension which finally penetrates almost to the spinning triangle
and which is responsible for the greater part of the thread breaks .
There is always a triangular bundle of fibres without twist at the exit of the rollers, this is called
as SPINNING TRIANGLE. Most of the end breaks originate at this point
To reduce end breakage rate following steps should be taken into consideration :
a) End breakage in ring spinning is because of slippage of fibers at the spinning triangle, the
grip of the front drafting roller should be increased by having a high top roller pressure.
b) Reduction in friction between ring & ring traveler could reduce tension during rotate of
traveler.
c) Measure should be taken to reduce mass irregularity of fiber straightening after carding.
d) The top roller is always shifted 3 to 6 mm forward compared to bottom roller. This is called
top roller overhang.This gives smoother running and smaller spinning triangle.
e) Best speed pattern of spindle speed to select to compensate yarn tension at bottom.
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Mr.T.Krishna, Mill Manager, Bala Rama Krishna Spg. Mills Pvt Ltd., Guntur, Andra Pradesh
The following are the reasons for higher end breakages in cop bottom stage in spinning.
1. Usage of traveller type which creates bigger and smaller balloons in size at bottom stage i.e.
lighter
Traveller creates bigger balloon and heavier traveller leads to smaller balloon.
2. Higher spindle speed at cop bottom stage which creates higher balloon in size and causing to
more breakages.
3. Lappet and cop height setting problem and causing the balloon touches the tip of the cop, it
leads to more breakage at cop bottom.
4. Vertical leveling and ring centering disturbance leads to more breakage.
5. Due to improper functioning of delay drafting while restarting after doff.
6. Due to bad work methods of doffing boys.
7. Due to insufficient length of under winding.
8. Due to malfunctioning of toggle lever.
9. Due to bad work methods of snider.
Remedies:
1. Optimum traveller to be used for optimum ballooning at bottom stage to control the breakage.
2. Set the speed pattern as parabolic type and set the max.speed at 25% of cop total length.
3. Lappet and cop tip distance to be adjusted as follows.
Lappet and cop tip distance = 2xd + 5mm (d= outside tube diameter)
4. Vertical leveling and ring centering to be checked and corrected in frequent intervals.
5. Proper functioning of delay drafting to be ensured and to be checked for every 3 months.
6. During doffing, doffing boy has to fit empty tube on spindle exactly and ends to be cut properly
Other wise it leads to more breakage at bottom stage.
7. In Speed pattern Program timing to be adjusted for required under winding.
8. Adjust the toggle lever to be released properly after doffing.
9. Instruct the spiders do not leave ends down and bobbin exhaustion while doffing stage.
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Mr. Vikram C. Patil, Maintenance Incharge, Shetkari Vinkari Coop Spg Mills Ltd. Islampur.
Maharastra
Reasons: --- Used traveller too light. Balloon collapsing or lashing against the separator, ----
Position of lappet hook height : more the height, more creation of unnecessary bulging of balloon
and narrow the height, rotating yarn touches the bobbin top., ----- The balloon control rings
positioned at a place where balloon forms maximum diameter, ---- Improper gauging of spindles at
the bottom stage. ----- Too much spindle speed at the cop bottom stage.
Remedies:---- Use the correct numbered travellers as per count, ----- Lappet hook height as per
standard setting - 2d + 3 to 5 mm of tube dia, ----- balloon control ring need to be set in the
proportion of 4:5 of the total balloon height at the ring rail side at the bottom stage, ------ Check
the poker bars, ring rail movement, ring centering and verticality of the Spindle, ----- Reduction of
the slow speed further 25 to 30 % and increasing at rest of Doff proportionately.
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Mr.B.K.Behera, Asst. Manager-Maint., Birla Cotsyn India Ltd., Malkapur, Maharastra
The following points are the main reason for more end breaks at cop bottom position.
1. Balloon height more
2. Bobbin tip touches the yarn
3. Improper setting of speed pattern
4. Improper centering of abc ring
5. Heavier ring traveller is used
6. Running of worn out traveller
7. Jerking motion of ring rail
8. Improper starting position of lappet
9. Improper back winding setting
10. Improper bobbin fitting & bobbin play
To avoid above problem, we should check & adjust the following;
1. To adjust the height of ABC ring at the center from lappet hook to ring
2. To choose proper lappet eye dia as per the count so as to avoid touching of yarn to bobbin tip
3. To keep slow speed at bottom & gradually increase the speed, to take maximum speed at 75% of
the total length
4. To maintain schedule of the ABC ring centering regularly & to take precaution to avoid ABC ring
bend by the doffer trolley
5. To choose proper ring traveller as per recommendation & maybe used one no lighter as more end
breaks in bottom (when other factors are correct)
6 To choose ring traveller considering to yarn count, material, spindle speed & rh% maintained in
the department.
7. To maintain proper schedule of ring traveller change to avoid running of worn out traveller
8. To give proper training to the worker for the use of ring traveller
9. To check heart cam play, toggle lever bearing, lifting tapes & pulley to maintain cleanliness of
lifting tapes & pulleys to avoid jerking motion of ring rail
10. To put proper winding gear to maintain proper tension during winding & binding of the cop build
11. To adjust proper starting position of the lappet rail so as to avoid touching of yarn to bobbin tip
--------------------------------------------------------------------------------------------------------------
Mr. R.Rajkumar, Factory Manager, Ramalakshmi Rotor Spg & Expg Co Ltd., Coimbatore
The end breakage rate is more in cop bottom stage in spinning because of spinning angle. It would
be variable depends upon the lift sizes of the ring frame manufacturers. Higher spinning angle
leads more ballooning. At cop bottom stage the ballooning is high.
Whenever the ballooning is high the resistance of yarn passage is high and also the friction
between ring and traveler will be high. So, due to high friction heat generation will be more.
Fiber tends to fuse when the yarn passes very close to the hot point, the upper most point of the
contact zone between the ring and traveler. The distance between the passing yarn and the hot
point, called the yarn passage. It depends on spindle speed, the flange number, the traveler shape
and the wire-cross section.
To overcome these problems special treatment and coating required for rings and traveler.
Traveler has considerable influence on the degree of heat dissipation.
The anti-wedge ring and other high-speed rings in combination with traveler of material profile in
the contact zone provide much larger areas of contact and thus gives improved heat dissipation.
Removing cop bottom building brackets (shaping) from the machine is one of the solutions.
Increasingly, yarn-winding position from the bottom of empty bobbin also reduces the breakage
level.
In my point of view, the travelers must have uniform microstructure and advanced coatings will help
the spinners to overcome the cop bottom breaks.
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Mr.P.Ravichandran, FM, Hariharan Spinners Ltd, Erode, Tamilnadu
An end break will occur at cop bottom due to the following main reasons.
1. Poor quality of Feed Roving material
2. Improper selection of drafting parameters & settings.
3. External fluffs and atmosphere conditions and
4. Poor selection of Ring dia and Traveller size according yarn count spun.
Even through if we maintain all parameters as required, at cop bottom stage, more breakage will
occur due to higher tension exerted on yarn at this stage.
To reduce breaks at bottom stage, we have to maintain the following.
1. Selection of Ring dia, (36mm for fine counts above 60s, 38mm for 40s-60s and 40mm for below 40s)
2. Ring Traveller selection and replacement schedule (7 days is ideal for cotton and 4 days for
synthetic).
3. Variable spindle speed.
4. Using ABC rings.
5. Correct spinning angle to exert twist up to front roll nip.
6. Correct RH%
7. Good quality yarn without weak places.
8. Angle of yarn pulling.
9. Optimum distance between lappet and bobbin, so that the yarn should not touch tip of the bobbin
at lowest position of Ring rail. Height of lappet to set accordingly.
---------------------------------------------------------------------------------------------------------------
Mr.Karuppaswamy, DSM, Maris Spinners Limited, Hunsur, Karnataka
Reasons:
1. Improper selection of traveller.
2. Improper lappet height setting and Centering.
3. Improper ABC ring size and improper ABC height.
4. Improper centering of ABC ring.
5. Damaged separators.
6. Improper speed settings.
7. Poor condition of bobbin tubes.
8. Fluff accumulation at spindle brake and jockey pullies and separator saddles
REMEDY:
1. Traveller to be selected according to count, ring diameters, lift, speeds and bobbins lift. For
smaller ring and lower lift - select lighter traveller.
For Larger ring and higher lift - select heavier traveller.
2. Lappet height setting around – Double the time of tube dia + 2 to 5 mm.
3. ABC ring Dia – ring + 2 to 3 mm.
4. ABC ring height – 2 / 3 of ring rail and lappet position at initial stage.
5. ABC should be perfectly centered.
6. Damaged separators to be replaced with proper height.
7. Speed should be selected according to spin ability of yarn.
8. Bobbins should be free from damaged tips and wobbling.
9. Bobbin run out should be less than 0.25 mm.
10. Tube length to rings ratio – 5:1.
11. Bobbin tube dia to rings ratio – 1:2.
12. Separator, spindle brakes, jockey pullies should be free from fluff.
---------------------------------------------------------------------------------------------------------------
Mr.S.K.Jindal, HOD – Spinning, Ginni International Ltd, Neemrana, Rajasthan
Reasons for higher end breakages at cop bottom are as follows:
1. If the ratio of ring dia (d) to tube dia (d) is not as per recommendation (2:1), then there will be
very high breakages at bottom position. The angle of yarn pull should be >= 30 degree.
2 .Too light ring traveller will lead to higher breakages at bottom of cop. this leads to larger
balloon size & hence higher breakages at cop bottom.
3 .If right combination of ring diameter (d) & tube length (l)is not used. it (d/l) should be around
1:4.5-5.0.higher length tubes will touch the yarn tip when the ring rail is at bottom position & hence
leads higher end breakages at cop bottom.
4 .If spindle speed is too high at bottom position of cop, then this will lead to more yarn tension &
hence more breakages, generally it should be 80-90 % of full spindle speed.
5. If cop diameter is too heavy at bottom. This restricts the movement of ring traveller due to
very less clearance between r/tr & yarn. This will lead more breakages at cop bottom.
6 .wrong selection of ring & ring traveller
7 lappet hook setting is too low (near the tip of tube).this leads rubbing of the yarn with tube tip &
hence more yarn bks at cop bottom.
Remedies :
1 We should use correct combination of ring dia with respect to tube length & tube dia.
2 Spindle speeds should be increased gradually from cop bottom to middle of cop.
3 Use right type ring traveller. (Weight, profile, make etc)
4 Lappet hook setting &cop dia should be correctly set
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Mr.M.R.Surendran, FM, Nallam Textiles Pvt.Ltd.,Vellakovil. Tamilnadu
Integrated fibre fleece of the drafted individual fibers emerging out of the front delivery roller
of the ring frame form YARN by the insertion of twist.
Unyielding to prevailing yarn pulling tension and other frictional forces due to the surface contact
at every zone all along the passage, the fibre bundle collapses and result in an END BREAK.
Specifically when cop bottom is considered breaks are more due to the following:
With longest length of yarn under process passing through different zones ie… Ring tube to ring
traveler, ring traveler to lappet-eye, lappet –eye to roller nip and the in-between zones frictional
forces, the probability of variation in twist distribution is relatively high and variation in tension is
also high disturbing the yarn strength substantially causing comparatively more breaks. As the ring
rail goes up crossing cop bottom the rate of break goes down gradually
To over come the cop bottom breaks - When twist is insufficient and variation in twist distribution
in between zones, initial speed to high, obstruction along the passage and non synchronization of
different zones - tension in twisting and winding process.
We should check technologically the following and correct:
1. Right selection of ring travelers with respect to flange, weight, bow height, wire section and
material on process.
2. Improperly run-in rings leads to uneven traveling surface of contact and exhibits abnormal
yarn tension causing breaks and breaks due to traveller fly. Sincere efforts to be exercised
to avert the trouble throughout the rings life. Also effect of fibre spin – finish is taken
care of to smoothen the ring traveller gliding surface.
3. Button less spindles, damaged bolsters, unsuitable cracked ring tubes, rings not changed as
per schedule, failure in adopting traveller change schedule causes alarmingly increased yarn
tension causes more breaks at cop bottom. Systems should be maintained without fail.
4. Improperly leveled ring rail, lappet rail, ANBC rail and separator sections are to be
corrected to lie in parallel without up and down or hanging towards one side or other.
5. ANBC ring diameter should not be lesser than ring diameter and the height should be set as
per the diameter of the ring and proper adjustment in ANBC height setting to control the
balloon without collapsing or not forming conical balloon welcoming unwanted tension. ANBC
ring should be free from damage of metal coating.
6. Traveller clearer setting to be done with the setting gauge allotted for the design of
clearer provided and they are to be secured firmly.
7. Lappet hook positioned straight and no tilting is allowed. It should have thread caching cuts
at the edge to hold the LONG THREAD falling after breaks at bottom stage further causing
lashes and simultaneous multiple breaks - Enhancing the breakage rate. Hardened ceramic
type or glass type of lappet hooks could be tried if feasible.
8. Correct procedure to be adopted to set the ring rail at bottom position and see height from
lappet eye to ring tube is the minimum just not touching the tube. Cam and cam bowl
damages if any to be sorted out timely to avoid jerky and jolting movement of ring rail
creating unusual tension causes weaker places to break. Till cop bottom complete the lappet
rail could be arrested to reduce the tension at the desired point. Or micro movement of
lappet rail could be sought.
May there be a number of reasons in process up to the drafting field beside roller nip, for more
breaks in particular to the cop bottom-the above indicated reasons appears to be vital and
summarized remedies could be resorted to control excessive breaks .
Better house keeping-cleaned drafting zones –spindle driving Zones-optimum blowing of OHTCsystematic
doffing and donning practices if perfectly adopted, added advantages could be reaped.
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Mr.D.Ramkumar, Factory Manager, Pongalur Spinning Mills (P)Ltd., Pongalur, Tamilnadu
Reasons for higher end breakage rate in cop bottom stage in spinning
The spinning geometry plays a very important role in effecting spg performance. Particularly
Yarn Tension is the vital role in higher end breakage rate in cop bottom due to the following
reasons.
· Angle of pull is poor due to unfavorable ratio of Ring dia to tube dia & ring dia to tube
length.
· Distance between lappet hook to bobbin top is greater or narrow.
· In correct Traveller clearer setting & wrong selection of Traveller profile and number.
· The balloon is nearly collapsing or lashing against the separator at the shoulder.
· Anti balloon control ring is not positioned.
· Higher speed at the cop bottom stage.
REMEDIES
Favorable ratio of Ring Dia to tube dia is 2:1, so the angle of pull is optimum.
Favorable ratio of Ring dia to tube length is 1:5
Distance between lappet hook to bobbin top is 2d + 5 mm. May be 35 to 38 mm is preferable.
Traveller clearer setting is 0.2 mm to 0.3 mm is advisable between Traveller to clearer.
Also using correct selection of traveller profile & number is must to control the balloon.
ABC Rings dia is 2 mm greater than ring dia. Distance of ring rail/abc ring (ring rail position)
= 2/3 of the distance ring rail/thread guide.
Speeds up to 20 to 30% reduced compared maximum speed. Now-a-days variator drive is
available in all types of frame. We make 3 steps up to cop bottom stage from startup
position with lowest speed.
Spindle & Lappet gauging Schedule is strictly followed.
-------------------------------------------------------------------------------------------------------------------------------
T.A.Shanmuga Sundaram, Mill Manager, Saravana Polythreads (P) Ltd., Gobi, Tamilnadu
Reason: At the cop bottom stage, due to the longer balloon dia meter and smaller winding on dia
meter (At bare bobbin) will result in very high tension in the yarn. As a result the maximum tension
is transmitted to the front roller nip at the time where minimum twist potential is available causes
for more breaks.
Remedies:
1. The spindle speed is to be reduced at the beginning stage of cop build.
2. Winding on tension: - To reduce the winding tension select the ring in respect to the spindle
DUI, it should be less than 1:2 for good working.
3. Control of Balloon size: - the balloon size depends upon the lappet position, traveller weight and
spindle speed. The lappet position should be 2.5 times of the dia meter of the bobbin measured at
the tip portion (Approx 25 to 35 mm).
4. Selection of Traveller Weight: - The traveller weight neither too heavy to touch the tip of the
bobbin nor light to lashing on to the separators.
5. Optimum Ring Rail Movement is set as slow as possible to maintain uniform tension during cop
build
6. Avoid Traveller Changes at the beginning of doffs especially in synthetic fibres to control
initial breaks.
7. Providing ABC rings helps to control breakages at bottom stage of cop build.
--------------------------------------------------------------------------------------------------------------
Mr.L.Muthuramalingam, FM, Gomathi Spinning Mills India (P) Ltd, Kunnathur, Tamilnadu
The Spinning tension (i.e.) the tension in the yarn between the front rollers and thread guide is one
of the main reasons for end breakage. Long term variations in the Spinning Tension which occur
over the duration of the doff at the nose as well as the shoulder of the chase on influence of the
end breakage. So the end breakage in cop bottom stage is mote than that in middle of the def
because the Spinning tension is high with larger balloons.
To over come these problem at the beginning, the spindle speed must be reduced and also by using
correct type of Traveller.
---------------------------------------------------------------------------------------------------------------
Mr.B.Jagannathan, Technical Adviser, SMP Textile Mills Ltd., Dindigul, Tamilnadu
The given below is the reasons for higher end breakage and remedy for each of them
1. Reduced spindle speed fro make up TNEB power shortage:- Use heavier Traveller and avoid
cop building. Maintain 3 MM gap to ring.
2. Improper lappet height:- 2D+5 MM of tube dia for lappet height
3. Lappet rail movement initiate from cop bottom build up:- Arrest lappet rail movement until ½
cop stage
4. Improper ring dia & tube dia:- 2:1 Ring & Tube dia, 1:5 Ring dia to tube length
5. Ring rail, spindle, tube variation:- Set vibration free
6. Poor ring / lappet centering:- Set accurate centering
7. Mix-up different thickness tubes:- Segregate ring tube and use
---------------------------------------------------------------------------------------------------------------
Mr.S.V.Srinivasan, SM, Tirupathi Yarntex Spinners (P) Ltd, Rajapalayam, Tamilnadu
The following are the reasons for higher end breakage and remedy for each of them
1. Poor Ring & Lappet Centering:- Correct Centering
2. Improper Selection of Traveller Number & Profile:- Proper Selection of Traveller Number &
Profile
3. Improper Selection of Empties Height: - Proper Selection of Empties Height, ie, Spindle Height
+ 10 mm
4. High speed of Ring rail Movement:- Correct Speed pattern at initial stage (after 25 % maximum
speed to be started -
5. Wrong Initial Lappet Height Setting:- Correct Initial Lappet Height Setting (2 d + 5mm)
6. Improper selection of ABC Ring dia: - Proper selection of ABC Ring dia (equal dia of Ring dia)
7. ABC Ring height variation at Cop Initial stage:- Standard ABC Ring height variation at Cop Initial
stage
8. Ring rail Play:- No Ring rail Play
9. Too much dia of Rings:- Optimum dia of Rings (Spindle blade height / 4 )
10. Wrong Speed pattern at initial stage:- Correct speed of Ring rail Movement
------------------------------------------------------------------------------------------------------------
Mr.Su.Bhaskaran, Sidhaarth Exports P Ltd, Annur, Tamilnadu
Higher tension due to finer Traveller i.e. Correct Traveller No. to be selected to avoid excess
ballooning at cop bottom stage.
Spindle to lappet height setting should be optimized i.e. (30mm) the yarn should not rub the cop tip,
and the balloon should not bigger than the gap between the two separators
The winding angle ratio should be optimum
Ring rail speed i.e. winding length should be optimum for concern Count.
Pulling angle should be great than 30deg.
Selection of Ring tube dia with respect to the Ring dia.
-----------------------------------------------------------------------------------------------------------
Mr.A.Senthilkumar, FM, Ganappathy Spinners, Vellakovil, Tamilnadu
Reason: Improper selection of Ring Traveller (i.e. Lighter Traveller) caused the end breakage in cop
bottom stage.
Remedies: We can use heavier Traveller to avoid the over ballooning & breakages. Adjust the
distance of lappet hook to spindle height setting depending upon the ballooning.
-------------------------------------------------------------------------------------
Mr.V.Sivasankar, Spinning Master, Raju Spinning Mills (P) Ltd., Rajapalayam, Tamilnadu
Reason for high end breakages at cop Bottom side
1. Wrong Traveller selection
2. Improper lappet& ABC ring height setting
3. Low outer diameter of empty tube on bottom side
4. Poor single yarn strength i.e. high cv value and also having poor csp.
5. Improper speed on (i.e. High speed ) cop bottom area .
6. Poor maintaining of RH%.
7. More distance between Ring & traveller clearer setting
Due to the above reasons for high end breakages are taking place at cop bottom.
------------------------------------------------------------------------------------------------------------
Mr.SP.Ravichandran, General Manager, Balaji Spinning, Aska, Orissa
Reasons for higher end breakages in cop bottom stage in spinning and remedies to control the same.
1. Proper selection of ring traveler with respect to ring life.
2. Evenness of the roving material
3. Spinning cop empties vs spindles for proper seatment.
4. Proper training to labours for stopping the spindles or
The empties will be disturbed and unnecessary end breaks in longer running.
5. Spindle tape condition and its life.
6. Improper selection of start up speeds. And gradually speed increase at bottom
position.
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Mr.Vinay Srivastav, DGM (Technical), Cheema Spintex Llimited, Lalru, Punjab
The three basic reasons for higher end breakages in cop bottom stage in spinning,
1. Improper selection of ring Traveller
2. Improper setting of ABC ring & lappet hook
3. Incorrect Sp.Speed pattern
Remedies point wise:
1. Use heavier ring Traveller
2. Proper gauge setting of ABC ring & lappet hook, Height setting of lappet hook to be corrected
3. Optimize speed pattern.
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Mr.K.Sudhakar, Manager, Santhose Spinning Mills, Coimbatore, Tamilnadu
Reasons: High winding tension due to improper winding angle between Ring and Traveller. Higher
spindle speed at initial stage, heavier traveller, poor ring, lappet and ABC centering, insufficient T/
M, improper height setting between empties top to lappet hook.
Remedies: Winding angle should be maintained from 30 to 34 degree, i.e empties Dui should be
selected according to ring dia. optimum speed and T.M to be selected at initial stage, according to
the raw material. Ring, ABC rings, spindles to be set perfectly with respect to each other, balloon
should not touch the empties top at any stage.
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Mr. S.Senthil Kumar, Manufacturing Manager, Thambbi Modern Spinning Mills, salem, Tamilnadu
Excessive yarn tension & ballooning are the main reason for higher breakages, particularly at cop
bottom.
I. Excessive yarn tension could be due to,
1. Selection of heavier traveler
2. In-adequate combination of ring: tube height ratio. It should be 1:5, higher the tube height
than recommendation results more initial breaks because the yarn touches the nose of the
empties
3. Improper concentric of lappet eye, spindle, and ring & Anti balloon rings
4. Excessive initial spindle speed
5. Improper cop bottom shape. I.e., Higher cop dia. Optimum cop dia should be = ring dia – 3mm
II. Higher yarn ballooning could be due to,
1. Selection of lighter traveler
2. Too high initial lappet height from top of the ring tube (Optimum – Ring dia + 2-3mm)
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Mr.S.Vasudevan – FM & Mr.B.Rajkumar – ASM, Mahendra Spinning Mills (P) Ltd, Navakkarai,
Tamilnadu
Reasons for more breakages at cop bottom.
1. Wrong Selection of Traveller (too heavy or too light)
2. Improper ring centering and spindle gauge.
3. Improper Height of lappet hook to ring tube.
4. Excess spindle speed at bottom stage.
Remedies.
Proper selection of Traveller, correct ring centering, correct lappet height setting. Optimum
spindle speed at cop bottom.
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Mr.S.Ramakrishnan, SM, Sri Rajalingam Tex, Vellakovil, Tamilnadu
Improper ballooning formation. Ballooning should touch the top of the paper tube and chase length
is very low and spindle speed is higher they will lead more breaks
Spindle speed to reduce 20% than the normal speed and at any cost Balloon should not touch the
top of the plastic tope (i.e. 2 times of top of the tube dia +5min to maintain)
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Mr.V.Kalaiarasu, ASM, Mehala Carona Textiles (P) Ltd, Gobichettipalayam, Tamilnadu.
The reason for speed pattern improper, Wrong choice of Traveller no, Lappet height setting
variation, Lappet rail lifting improper, Chase length variation, Base running time ring rail up and
down motion speed high are few important reasons for higher end breakage in cop bottom stage in
spinning. If you rectify the above, breakage rate will reduce.
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Mrs. D.Jagathambal, SM, Thanigaivelan Spinning Mills Ltd., Annur, Tamilnadu
Cop bottom stage end breakages occurs due to use of low G/tex cotton, shore hardness of the top
rollers, Top arm pressure applied type of traveler, constant drive motors lack of control of
temperature and humidity.
To control with gradual speed motor drive, better cotton, combing or higher twist insertion RH55%
and temperature about 80°F.
-------------------------------------------------------------------------------------------------------------------------------
Mr.S.Karthikeyan, SM, Shree Raam Mills, Gobichettipalayam, Tamilnadu
Reason for higher end breakage in cop bottom stage in spinning frame lappet to Ring rail distance
high level for cop bottom stage so ballooning form high, this ballooning form create yarn tension
higher this tension is form to end breakages in higher for cop bottom stage.
Remeties
(i) First step ring rail to lappet distance reduce
(II) Correct selection for ring traveller
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Mr.S.Muthumanikam,FM,AKCT Chidambaram Cotton Mills (P) Ltd, Thiruvannamalai, Tamilnadu
The distance between lappet eye and ring is higher at bottom stage. That is making bigger balloon
and higher tension. Higher yarn tension creates higher end breakage.
REMEDIES:
1. Minimum size and Good condition of lappet eye according to the count.
2. Optimum distance between ring tube and Lappet eye.
3. Optimum Ring traveler number to control the balloon size at bottom stage.
4. Ring Frame must be provided with Anti balloon Control ring.
-------------------------------------------------------------------------------------------------------------------------------
Question: Explain the reasons for higher end breakage in cop bottom stage in
spinning? What are remedies to control the same?
******
Mr.Ayub Khan, Naheed Composite Textiles, Dhaka, Bangladesh
Following are the some points for higher breakage arte in cop bottom stage:
1. Improper selection of ring Travellers, e.g., Traveller weight, height and cross section
2. Improper setting of lappet height and abc ring height
3. The spindle speed grasp is not properly set
4. Variation in ring & spindle centering
5. Improper selection of TM in the count
6. Improper selection of spacer & top arm pressure
7. Cop build at bottom is not properly setting
8. Worn-out separators
9. Chase length is not properly set as per ring diameter
10. The diameter of bobbin should be always min 2.5 MM lesser than ring diameter
11. Improper selection of ring diameter vs. lift & count spun
12. Improper humidity and temperature.
With the above points, we can reduce breakage at cop bottom stage.
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Mr.Desu Purnachandra Rao, FM, Kallam Brothers Cottons Pvt Ltd. Guntur, Andrapradesh
The main reason for more end breaks at cop bottom is the angle of pull is very height and the
balloon size is more that means the yarn from the front roller to cop bottom is more. So we have to
handle the more length of yarn. The breaking of long thread is very easy than the shorter length
threads. The weak place / thin place / contamination of jute or hair will cause to break in this stage
is height. The following were the some of the tips to minimize the end breaks.
1. If the balloon size is more or less it should not touch the tip of the cop.
2. To control the large balloon we need the heavier traveller at this stage if we maintain the same
speed. So that instead of traveller we are reducing the spindle speed at this cop bottom stage.
3. The contact of ring traveller is more at this stage. We have to observe the traveller fly. If it
found more, we have to go for heavier.
4. The ring rail / ring should perfectly 90 deg to spindle “x “and “y “axis. Normally the spindle gauge
will take place at the ¾ stage of cop. It is advisable to check at cop bottom also.
5. We can observe the more cop bottom breaks at the end of traveller life.
6. Ring dia vs. empty cop bottom dia will also play the more end breaks. E.g. a) The ring dia 40 mm,
empty cop dia at bottom is 20 mm. B) the ring dia 38mm, empty cop dia at bottom is 20 mm. We can
observe lesser end breaks at cop bottom in sample “b”.
7. The spindle speed to be increase slowly at cop bottom stage also help to reduce the end breaks
less at cop bottom.
8. The traveller loading also will effect more ends breaks at cop bottom.
9. More rh % and fluff level also effect the end breaks more at cop bottom.
10. More trash and kitties in yarn also affect the end breaks more at cop bottom.
11. The selection of traveller profile i.e. the clearance for yarn path to be more for more ipi yarn.
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Mr.P.Sakthivel, Spinning Master, Mani Spinning Mills, Vedasandur, Tamilnadu
Reason: The strain on the yarn is maximum level at the bottom of the ring rail position; secondly
the Traveller has to make more rotation to lay the delivered yarn on the empty cop immediately
after doffing. As the cop builds up the rotation of Traveller educes and there by reduction in yarn
tension. These two factors are causing more end breaks at the bottom of the cop position.
Remedies:
1. Selecting the lower spindle speed of 50 to 60% to that of highest spindle speed in the full
doff speed cycle and depending upon the single yarn strength
2. Selecting lesser rind diameter
3. Selecting the ratio of tube length and ring diameter to be 5:1.
4. Setting the lappet hook distance from top of the tube to be two times of top portion
diameter of ring tube.
5. Selecting higher wall thickness ring tubes
6. Selecting lighter Traveller with smooth surface finish
7. Setting Traveller clearer to be 0.25MM to Traveller.
8. Keeping ABC Rings, rings, spindles and lappet eye concentric.
9. Selecting ring tubes with no eccentric running.
10. Selecting optimum spindle triangle.
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Engr. Hasan (Kazi Hasanul Karim), Asst. Manager – Maintenance, Akij Textile Mills Ltd. Manikgonj,
Bangladesh.
Reasons for end breakage in cop bottom stage in spinning:
1. Not proper under winding
2. Speed not synchronies with count-ring traveller-cops dia-full bobbin dia etc
3. Pre twist not proper
4. Top or bottom bunch not proper
5. Doffing time yarn not stays in ring traveller.
Remedies:
1. Proper settings of speed pattern-pre twist-under winding-etc.
2. ,Doffing should be done such way that yarn not breakage and out from ring traveller,
3. Under winding place should be clean ( remove waste yarns)
At last we can say that, if we want to reduce end breakage we must to ensure the tension and twist
whole that cop should same of considerable.
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Mr.V.Duraiswamy, General Manager. JG Spinning Mills Pvt Ltd., Annur, Tamilnadu
Improper selection of Traveller number, Lighter Traveller will give excessive balloon and created
breaks, excessive height of Ring tubes (25 to 35mm) above spindle tip, also worn-out or scratch
Ring tube tip will give higher brakeage. Wrong setting or selection of spindle speed at cop bottom
will create higher yarn tension and breaks.
Remedies to control the cop bottom breaks
Right Traveller number should be used such that, yarn ball on should not touch separators as well as
Ring tube tip. It can be observed by using 1 No. heavier and 1 No. lighter Traveller than normal
Traveller number side by side for few spindles and decide the correct yarn tension and right
Traveller Number.
The spindle speed of Ring frame should be set 30 to 40% lower than the Maximum spindle speed
till cop reach 30% of content. The Ring tube height should be 10mm to 15mm than spindle lift.
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Mr.Sudhakar Kodela, Technical director, Spincot Textiles Pvt. Ltd., Guntur, Andrapradesh
Generally Yarn break occurs when current spinning tension in the spinning process at cop bottom is
higher than the current yarn strength. The following are the reasons for high incidence of breaks
at cop bottom.
Problem Reason Remedial measure
1. Balloon size high - Low traveler weight Increase traveler weight
2. Balloon touching
Separators - Low traveler weight Increase traveler weight and
3. Damaged separators - holed, cuts on separators Replace with new the separators.
4.Improper ABC ring dia - Recommended dia is
ring dia+2 mm Replace with rec.size of ABC ring.
5. Improper distance of - 2/3 of the distance of Check the distance and adjust
ABC ring fixation ring rail is suggested accordingly.
6. Bend/scratched - It obstructs the free flow Replace with new ABC ring.
Balloon ring of yarn and increase
yarn tension.
7. Fixing ‘S’twist ABC - The yarn flow will not be Replace with ‘Z’ or Universal
Rings in ‘Z’ twist m/c. be free. ABC ring.
8. Balloon touching the - traveler is heavy try with lighter traveler.
Tip of the bobbin.
9. Balloon touching the improper lappet gauge. Adjust the lappet gauge.
one side of the bobbin.
10. Collapsing balloon Improper size/profile of try with correct profile/size of
Traveller. The traveller.
11.Improper setting of Increases yarn tension. Correct the thread guide setting.
thread guide.
12.Physical damage to obstructs yarn flow replace with new thread guide.
thread guide.
13.Orifice of the thread - creates improper balloon. Smaller for fine count(1.8-2.2mm).
guide. 2.5-3.0 mm for other counts.
14.Thread guide distance - creates improper balloon optimize as per machinery
To empty tube. Manufacture recommendations.
15.Tube length is more - Lower tube length/lower Optimize the tube length as
Lift reduces tension. Per the lift of the machine.
16.Damaged ring tubes - obstructs yarn flow Remove such tubes by
periodical inspection.
17.concentricity of tubes increases yarn tension use tubes with better
Dimensional stability.
18.improper ring centering - increases yarn tension correct centering.
19.bend spindle plug - rotates eccentrically replace the spindle.
20.Improper locking of - wear & tear at button replace the empties.
Tubes on spindle. area.More slippage occurs.
21.Ratio of ring/tube - ideal is 1:5 Use suitable ring tube
length ring &tube dia 2:1 length and dia of tube.
22.Ring condition - bad ring will not allow replace the ring.
yarn to run.
23. Accumulation of - traveller will not freely wipe with dry cloth.
micro dust on ring
surface.
24.Traveller too light - poor twist contraction of fibres try with increased
Heavy friction of the balloon on traveller weight.
Anti ballooning ring.
25.Traveller too heavy - increase yarn tension/ reduce traveller wt.
Too low balloon.
26.worn out traveler - obstructs free rotation of adjust the traveller
traveller change schedule.
27.High spindle speed - increases yarn tension optimize the spindle
At bottom speed at bottom.
28. Clearance between - fibres protruding from the optimize clearance.
Cop and ring cop will be catched by traveler.
29.Too low centre to - air turbulance will carry fibres to while planning the project
Centre distance adjascent ring frame and effects sufficient space is to be
between ring frames. the working at bottom. left/ or to reduce the
spindle speed.
30.too much rolling fluff - improper grills of exhaust. To modify and provide
on the floor. Sufficient no. of grills.
31.yarn unthreading from - yarn comes out of the traveler change traveler type/
traveller when RF restarted after doff. profile.
32.over cop bottom - yarn touches the ring reduce the cop bottom
33.Improper short snarl - due to snarls more breaks occur adjust delay draft setting.
Removal. at the bottom after restart.
34.Traveller flying at - Improper size/type of traveler. Choose low bow height
Bottom traveler/try with other type.
35.Traveller clearer setting - fluff accumulates on traveler adjust clear setting.
36.type of traveler cleaner - tangential type is suitable for check for type suitability
High spindle speeds.
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Mr. Sarba Narayan Sen, Maintenance Manager, Jalal Ahmed Spinning Mills Ltd., Narayanganj,
Bangladesh
The Mechanics of higher end breakage in Cop Bottom stage lies mainly on the geometry of yarn
passage from the Front Roller nip to the Ring Bobbin through the lappet eye and the Ring Traveller.
The usual system of slow start with smooth increase of spindle speed is a good choice. Higher
Spinning Angle at the start also contributes greatly to achieve the desired result. Rising and falling
lappet is a good solution. To increase the Angle of Wrap, sharply tapered bobbin at the bottom up
to ¼th of the lift can be opted. Suitable choice of Cop Builder for low chase length at bottom will
increase the Angle of Wrap at a faster rate. Proper selection of Ring Traveller is also of prime
importance. Finally, well polished and proper size hole diameter of the lappet eye for even
distribution of twist flow and smooth passage of yarn respectively will certainly ensure the
breakage rate at the cop bottom to minimum.
------------------------------------------------------------------------------------------------------------------------------------------------
Mr.K.Murali, Production Manager, Rohini Textile Industries Ltd., Sathyamangalam, Tamilnadu
In ring spinning generally all spinners are aiming for best possible production and productivity
through minimizing the end breakage rate which in turn is governed by yarn balloon tension. As the
yarn balloon size and shape vary from cop bottom to cop full size the yarn tension could not be
uniform through the cop bottom to cop full size. For the given yarn count the initial yarn balloon
tension gradually reduces with respect the ring rail upward movement.
Thus the balloon tension level of yarn exhibits maximum during cop bottom and cop initial stages.
Of course the spindle speed, traveler weight, angle of yarn pull, spinning triangle and spinning
geometry are also criteria for end breakage rate higher at cop bottom stage.
Hence the cop bottom stage breakage is mainly due to higher yarn balloon tension. For intensified
analysis of yarn tension cop build up package can be divided in to two stages
STAGE I: Upto cop package taper formation
STAGE II after cop package taper formation
In stage I the tension imposed on yarn comparatively higher than stage II. Because of the
following reasons.
· Higher balloon size and balloon weight.
· Angle of yarn pull remains low and remains almost constant in stage I
· Whereas in stage II cop package dia increases , angle of yarn pull also increases and inertly
variable within chase length causing smooth gliding of traveler resulting lower tension on
yarn and reduces end breakage rate.
· Twist free flow to the front roller nip, higher length of spinning yarn i.e. from front fluted
roller nip to traveler reduces twist free flow which causing spinning triangle at nip stitch
possibilities, in turn causing end breakage in yarn. This will be more at cop bottom stages.
REMEDIES
Faultless condition of support and guide of the ring rail as well as steady traverse motion.
Concentric position of ring and spindle as well as anti ballooning ring and yarn guide.
Spindle rotation without vibration and correct concentricity of bobbin tube.
Ring with exact roundness and firm seating in horizontal position.
Correct setting of traveler clearer ( 0.2 to 0.3 mm )
Favorable ring dia to tube dia ratio 2 : 1
Favorable ring dia to tube length ratio 1 : 5
Proper position of lappet height from bobbin tube tip 2D + 5 mm of tube dia
Good combination of ring and traveler profile , which should not either less area of contact
of ring to traveler or less yarn passage space .( less Horn – Play )
Do right selection of correct type of traveler and correct number (traveler weight) with
respect to the count to be spun, material, ring dia, spindle speed, yarn strength and life of
ring.
Keeping lesser spindle speed in bottom stage and higher speed in after bottom stage to
narrow down the yarn tension difference. This may be tuned with the feed back report of
full doff end breakage rate study.
Disc type pulley and variator belt provision for step less spindle speed control with
computerized programmed spindle speed table.
Minimum ring dia adoption ( 36 mm , 38 mm ) with 1 : 40 ,1:64 taper ratio .
Adoption of anti balloon control rings , lesser dia lappet hooks.
Selection of short stitch spinning geometry. (18deg,24deg3mts)minimum and maximum
degree of angle covered by the line of front roll nip to lappet eye to the axis line of spindle.
Replacement of worn out rings , up keeping of builder motion mechanical component .
Fine tuning of traveler weight taking in to the account of end breakage study feed back.
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Mr.Sudip Nandy ,General Manager (production), DCM Textiles, Hissar, Haryana
Tensile force / yarn tension exerted on yarn must be much higher during winding on the bare tube
than during winding on the full cop, because of the difference in the angle of attack of the yarn on
the traveller.
Yarn tension in the balloon is the tension which finally penetrates almost to the spinning triangle
and which is responsible for the greater part of the thread breaks .
There is always a triangular bundle of fibres without twist at the exit of the rollers, this is called
as SPINNING TRIANGLE. Most of the end breaks originate at this point
To reduce end breakage rate following steps should be taken into consideration :
a) End breakage in ring spinning is because of slippage of fibers at the spinning triangle, the
grip of the front drafting roller should be increased by having a high top roller pressure.
b) Reduction in friction between ring & ring traveler could reduce tension during rotate of
traveler.
c) Measure should be taken to reduce mass irregularity of fiber straightening after carding.
d) The top roller is always shifted 3 to 6 mm forward compared to bottom roller. This is called
top roller overhang.This gives smoother running and smaller spinning triangle.
e) Best speed pattern of spindle speed to select to compensate yarn tension at bottom.
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Mr.T.Krishna, Mill Manager, Bala Rama Krishna Spg. Mills Pvt Ltd., Guntur, Andra Pradesh
The following are the reasons for higher end breakages in cop bottom stage in spinning.
1. Usage of traveller type which creates bigger and smaller balloons in size at bottom stage i.e.
lighter
Traveller creates bigger balloon and heavier traveller leads to smaller balloon.
2. Higher spindle speed at cop bottom stage which creates higher balloon in size and causing to
more breakages.
3. Lappet and cop height setting problem and causing the balloon touches the tip of the cop, it
leads to more breakage at cop bottom.
4. Vertical leveling and ring centering disturbance leads to more breakage.
5. Due to improper functioning of delay drafting while restarting after doff.
6. Due to bad work methods of doffing boys.
7. Due to insufficient length of under winding.
8. Due to malfunctioning of toggle lever.
9. Due to bad work methods of snider.
Remedies:
1. Optimum traveller to be used for optimum ballooning at bottom stage to control the breakage.
2. Set the speed pattern as parabolic type and set the max.speed at 25% of cop total length.
3. Lappet and cop tip distance to be adjusted as follows.
Lappet and cop tip distance = 2xd + 5mm (d= outside tube diameter)
4. Vertical leveling and ring centering to be checked and corrected in frequent intervals.
5. Proper functioning of delay drafting to be ensured and to be checked for every 3 months.
6. During doffing, doffing boy has to fit empty tube on spindle exactly and ends to be cut properly
Other wise it leads to more breakage at bottom stage.
7. In Speed pattern Program timing to be adjusted for required under winding.
8. Adjust the toggle lever to be released properly after doffing.
9. Instruct the spiders do not leave ends down and bobbin exhaustion while doffing stage.
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Mr. Vikram C. Patil, Maintenance Incharge, Shetkari Vinkari Coop Spg Mills Ltd. Islampur.
Maharastra
Reasons: --- Used traveller too light. Balloon collapsing or lashing against the separator, ----
Position of lappet hook height : more the height, more creation of unnecessary bulging of balloon
and narrow the height, rotating yarn touches the bobbin top., ----- The balloon control rings
positioned at a place where balloon forms maximum diameter, ---- Improper gauging of spindles at
the bottom stage. ----- Too much spindle speed at the cop bottom stage.
Remedies:---- Use the correct numbered travellers as per count, ----- Lappet hook height as per
standard setting - 2d + 3 to 5 mm of tube dia, ----- balloon control ring need to be set in the
proportion of 4:5 of the total balloon height at the ring rail side at the bottom stage, ------ Check
the poker bars, ring rail movement, ring centering and verticality of the Spindle, ----- Reduction of
the slow speed further 25 to 30 % and increasing at rest of Doff proportionately.
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Mr.B.K.Behera, Asst. Manager-Maint., Birla Cotsyn India Ltd., Malkapur, Maharastra
The following points are the main reason for more end breaks at cop bottom position.
1. Balloon height more
2. Bobbin tip touches the yarn
3. Improper setting of speed pattern
4. Improper centering of abc ring
5. Heavier ring traveller is used
6. Running of worn out traveller
7. Jerking motion of ring rail
8. Improper starting position of lappet
9. Improper back winding setting
10. Improper bobbin fitting & bobbin play
To avoid above problem, we should check & adjust the following;
1. To adjust the height of ABC ring at the center from lappet hook to ring
2. To choose proper lappet eye dia as per the count so as to avoid touching of yarn to bobbin tip
3. To keep slow speed at bottom & gradually increase the speed, to take maximum speed at 75% of
the total length
4. To maintain schedule of the ABC ring centering regularly & to take precaution to avoid ABC ring
bend by the doffer trolley
5. To choose proper ring traveller as per recommendation & maybe used one no lighter as more end
breaks in bottom (when other factors are correct)
6 To choose ring traveller considering to yarn count, material, spindle speed & rh% maintained in
the department.
7. To maintain proper schedule of ring traveller change to avoid running of worn out traveller
8. To give proper training to the worker for the use of ring traveller
9. To check heart cam play, toggle lever bearing, lifting tapes & pulley to maintain cleanliness of
lifting tapes & pulleys to avoid jerking motion of ring rail
10. To put proper winding gear to maintain proper tension during winding & binding of the cop build
11. To adjust proper starting position of the lappet rail so as to avoid touching of yarn to bobbin tip
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Mr. R.Rajkumar, Factory Manager, Ramalakshmi Rotor Spg & Expg Co Ltd., Coimbatore
The end breakage rate is more in cop bottom stage in spinning because of spinning angle. It would
be variable depends upon the lift sizes of the ring frame manufacturers. Higher spinning angle
leads more ballooning. At cop bottom stage the ballooning is high.
Whenever the ballooning is high the resistance of yarn passage is high and also the friction
between ring and traveler will be high. So, due to high friction heat generation will be more.
Fiber tends to fuse when the yarn passes very close to the hot point, the upper most point of the
contact zone between the ring and traveler. The distance between the passing yarn and the hot
point, called the yarn passage. It depends on spindle speed, the flange number, the traveler shape
and the wire-cross section.
To overcome these problems special treatment and coating required for rings and traveler.
Traveler has considerable influence on the degree of heat dissipation.
The anti-wedge ring and other high-speed rings in combination with traveler of material profile in
the contact zone provide much larger areas of contact and thus gives improved heat dissipation.
Removing cop bottom building brackets (shaping) from the machine is one of the solutions.
Increasingly, yarn-winding position from the bottom of empty bobbin also reduces the breakage
level.
In my point of view, the travelers must have uniform microstructure and advanced coatings will help
the spinners to overcome the cop bottom breaks.
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Mr.P.Ravichandran, FM, Hariharan Spinners Ltd, Erode, Tamilnadu
An end break will occur at cop bottom due to the following main reasons.
1. Poor quality of Feed Roving material
2. Improper selection of drafting parameters & settings.
3. External fluffs and atmosphere conditions and
4. Poor selection of Ring dia and Traveller size according yarn count spun.
Even through if we maintain all parameters as required, at cop bottom stage, more breakage will
occur due to higher tension exerted on yarn at this stage.
To reduce breaks at bottom stage, we have to maintain the following.
1. Selection of Ring dia, (36mm for fine counts above 60s, 38mm for 40s-60s and 40mm for below 40s)
2. Ring Traveller selection and replacement schedule (7 days is ideal for cotton and 4 days for
synthetic).
3. Variable spindle speed.
4. Using ABC rings.
5. Correct spinning angle to exert twist up to front roll nip.
6. Correct RH%
7. Good quality yarn without weak places.
8. Angle of yarn pulling.
9. Optimum distance between lappet and bobbin, so that the yarn should not touch tip of the bobbin
at lowest position of Ring rail. Height of lappet to set accordingly.
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Mr.Karuppaswamy, DSM, Maris Spinners Limited, Hunsur, Karnataka
Reasons:
1. Improper selection of traveller.
2. Improper lappet height setting and Centering.
3. Improper ABC ring size and improper ABC height.
4. Improper centering of ABC ring.
5. Damaged separators.
6. Improper speed settings.
7. Poor condition of bobbin tubes.
8. Fluff accumulation at spindle brake and jockey pullies and separator saddles
REMEDY:
1. Traveller to be selected according to count, ring diameters, lift, speeds and bobbins lift. For
smaller ring and lower lift - select lighter traveller.
For Larger ring and higher lift - select heavier traveller.
2. Lappet height setting around – Double the time of tube dia + 2 to 5 mm.
3. ABC ring Dia – ring + 2 to 3 mm.
4. ABC ring height – 2 / 3 of ring rail and lappet position at initial stage.
5. ABC should be perfectly centered.
6. Damaged separators to be replaced with proper height.
7. Speed should be selected according to spin ability of yarn.
8. Bobbins should be free from damaged tips and wobbling.
9. Bobbin run out should be less than 0.25 mm.
10. Tube length to rings ratio – 5:1.
11. Bobbin tube dia to rings ratio – 1:2.
12. Separator, spindle brakes, jockey pullies should be free from fluff.
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Mr.S.K.Jindal, HOD – Spinning, Ginni International Ltd, Neemrana, Rajasthan
Reasons for higher end breakages at cop bottom are as follows:
1. If the ratio of ring dia (d) to tube dia (d) is not as per recommendation (2:1), then there will be
very high breakages at bottom position. The angle of yarn pull should be >= 30 degree.
2 .Too light ring traveller will lead to higher breakages at bottom of cop. this leads to larger
balloon size & hence higher breakages at cop bottom.
3 .If right combination of ring diameter (d) & tube length (l)is not used. it (d/l) should be around
1:4.5-5.0.higher length tubes will touch the yarn tip when the ring rail is at bottom position & hence
leads higher end breakages at cop bottom.
4 .If spindle speed is too high at bottom position of cop, then this will lead to more yarn tension &
hence more breakages, generally it should be 80-90 % of full spindle speed.
5. If cop diameter is too heavy at bottom. This restricts the movement of ring traveller due to
very less clearance between r/tr & yarn. This will lead more breakages at cop bottom.
6 .wrong selection of ring & ring traveller
7 lappet hook setting is too low (near the tip of tube).this leads rubbing of the yarn with tube tip &
hence more yarn bks at cop bottom.
Remedies :
1 We should use correct combination of ring dia with respect to tube length & tube dia.
2 Spindle speeds should be increased gradually from cop bottom to middle of cop.
3 Use right type ring traveller. (Weight, profile, make etc)
4 Lappet hook setting &cop dia should be correctly set
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Mr.M.R.Surendran, FM, Nallam Textiles Pvt.Ltd.,Vellakovil. Tamilnadu
Integrated fibre fleece of the drafted individual fibers emerging out of the front delivery roller
of the ring frame form YARN by the insertion of twist.
Unyielding to prevailing yarn pulling tension and other frictional forces due to the surface contact
at every zone all along the passage, the fibre bundle collapses and result in an END BREAK.
Specifically when cop bottom is considered breaks are more due to the following:
With longest length of yarn under process passing through different zones ie… Ring tube to ring
traveler, ring traveler to lappet-eye, lappet –eye to roller nip and the in-between zones frictional
forces, the probability of variation in twist distribution is relatively high and variation in tension is
also high disturbing the yarn strength substantially causing comparatively more breaks. As the ring
rail goes up crossing cop bottom the rate of break goes down gradually
To over come the cop bottom breaks - When twist is insufficient and variation in twist distribution
in between zones, initial speed to high, obstruction along the passage and non synchronization of
different zones - tension in twisting and winding process.
We should check technologically the following and correct:
1. Right selection of ring travelers with respect to flange, weight, bow height, wire section and
material on process.
2. Improperly run-in rings leads to uneven traveling surface of contact and exhibits abnormal
yarn tension causing breaks and breaks due to traveller fly. Sincere efforts to be exercised
to avert the trouble throughout the rings life. Also effect of fibre spin – finish is taken
care of to smoothen the ring traveller gliding surface.
3. Button less spindles, damaged bolsters, unsuitable cracked ring tubes, rings not changed as
per schedule, failure in adopting traveller change schedule causes alarmingly increased yarn
tension causes more breaks at cop bottom. Systems should be maintained without fail.
4. Improperly leveled ring rail, lappet rail, ANBC rail and separator sections are to be
corrected to lie in parallel without up and down or hanging towards one side or other.
5. ANBC ring diameter should not be lesser than ring diameter and the height should be set as
per the diameter of the ring and proper adjustment in ANBC height setting to control the
balloon without collapsing or not forming conical balloon welcoming unwanted tension. ANBC
ring should be free from damage of metal coating.
6. Traveller clearer setting to be done with the setting gauge allotted for the design of
clearer provided and they are to be secured firmly.
7. Lappet hook positioned straight and no tilting is allowed. It should have thread caching cuts
at the edge to hold the LONG THREAD falling after breaks at bottom stage further causing
lashes and simultaneous multiple breaks - Enhancing the breakage rate. Hardened ceramic
type or glass type of lappet hooks could be tried if feasible.
8. Correct procedure to be adopted to set the ring rail at bottom position and see height from
lappet eye to ring tube is the minimum just not touching the tube. Cam and cam bowl
damages if any to be sorted out timely to avoid jerky and jolting movement of ring rail
creating unusual tension causes weaker places to break. Till cop bottom complete the lappet
rail could be arrested to reduce the tension at the desired point. Or micro movement of
lappet rail could be sought.
May there be a number of reasons in process up to the drafting field beside roller nip, for more
breaks in particular to the cop bottom-the above indicated reasons appears to be vital and
summarized remedies could be resorted to control excessive breaks .
Better house keeping-cleaned drafting zones –spindle driving Zones-optimum blowing of OHTCsystematic
doffing and donning practices if perfectly adopted, added advantages could be reaped.
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Mr.D.Ramkumar, Factory Manager, Pongalur Spinning Mills (P)Ltd., Pongalur, Tamilnadu
Reasons for higher end breakage rate in cop bottom stage in spinning
The spinning geometry plays a very important role in effecting spg performance. Particularly
Yarn Tension is the vital role in higher end breakage rate in cop bottom due to the following
reasons.
· Angle of pull is poor due to unfavorable ratio of Ring dia to tube dia & ring dia to tube
length.
· Distance between lappet hook to bobbin top is greater or narrow.
· In correct Traveller clearer setting & wrong selection of Traveller profile and number.
· The balloon is nearly collapsing or lashing against the separator at the shoulder.
· Anti balloon control ring is not positioned.
· Higher speed at the cop bottom stage.
REMEDIES
Favorable ratio of Ring Dia to tube dia is 2:1, so the angle of pull is optimum.
Favorable ratio of Ring dia to tube length is 1:5
Distance between lappet hook to bobbin top is 2d + 5 mm. May be 35 to 38 mm is preferable.
Traveller clearer setting is 0.2 mm to 0.3 mm is advisable between Traveller to clearer.
Also using correct selection of traveller profile & number is must to control the balloon.
ABC Rings dia is 2 mm greater than ring dia. Distance of ring rail/abc ring (ring rail position)
= 2/3 of the distance ring rail/thread guide.
Speeds up to 20 to 30% reduced compared maximum speed. Now-a-days variator drive is
available in all types of frame. We make 3 steps up to cop bottom stage from startup
position with lowest speed.
Spindle & Lappet gauging Schedule is strictly followed.
-------------------------------------------------------------------------------------------------------------------------------
T.A.Shanmuga Sundaram, Mill Manager, Saravana Polythreads (P) Ltd., Gobi, Tamilnadu
Reason: At the cop bottom stage, due to the longer balloon dia meter and smaller winding on dia
meter (At bare bobbin) will result in very high tension in the yarn. As a result the maximum tension
is transmitted to the front roller nip at the time where minimum twist potential is available causes
for more breaks.
Remedies:
1. The spindle speed is to be reduced at the beginning stage of cop build.
2. Winding on tension: - To reduce the winding tension select the ring in respect to the spindle
DUI, it should be less than 1:2 for good working.
3. Control of Balloon size: - the balloon size depends upon the lappet position, traveller weight and
spindle speed. The lappet position should be 2.5 times of the dia meter of the bobbin measured at
the tip portion (Approx 25 to 35 mm).
4. Selection of Traveller Weight: - The traveller weight neither too heavy to touch the tip of the
bobbin nor light to lashing on to the separators.
5. Optimum Ring Rail Movement is set as slow as possible to maintain uniform tension during cop
build
6. Avoid Traveller Changes at the beginning of doffs especially in synthetic fibres to control
initial breaks.
7. Providing ABC rings helps to control breakages at bottom stage of cop build.
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Mr.L.Muthuramalingam, FM, Gomathi Spinning Mills India (P) Ltd, Kunnathur, Tamilnadu
The Spinning tension (i.e.) the tension in the yarn between the front rollers and thread guide is one
of the main reasons for end breakage. Long term variations in the Spinning Tension which occur
over the duration of the doff at the nose as well as the shoulder of the chase on influence of the
end breakage. So the end breakage in cop bottom stage is mote than that in middle of the def
because the Spinning tension is high with larger balloons.
To over come these problem at the beginning, the spindle speed must be reduced and also by using
correct type of Traveller.
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Mr.B.Jagannathan, Technical Adviser, SMP Textile Mills Ltd., Dindigul, Tamilnadu
The given below is the reasons for higher end breakage and remedy for each of them
1. Reduced spindle speed fro make up TNEB power shortage:- Use heavier Traveller and avoid
cop building. Maintain 3 MM gap to ring.
2. Improper lappet height:- 2D+5 MM of tube dia for lappet height
3. Lappet rail movement initiate from cop bottom build up:- Arrest lappet rail movement until ½
cop stage
4. Improper ring dia & tube dia:- 2:1 Ring & Tube dia, 1:5 Ring dia to tube length
5. Ring rail, spindle, tube variation:- Set vibration free
6. Poor ring / lappet centering:- Set accurate centering
7. Mix-up different thickness tubes:- Segregate ring tube and use
---------------------------------------------------------------------------------------------------------------
Mr.S.V.Srinivasan, SM, Tirupathi Yarntex Spinners (P) Ltd, Rajapalayam, Tamilnadu
The following are the reasons for higher end breakage and remedy for each of them
1. Poor Ring & Lappet Centering:- Correct Centering
2. Improper Selection of Traveller Number & Profile:- Proper Selection of Traveller Number &
Profile
3. Improper Selection of Empties Height: - Proper Selection of Empties Height, ie, Spindle Height
+ 10 mm
4. High speed of Ring rail Movement:- Correct Speed pattern at initial stage (after 25 % maximum
speed to be started -
5. Wrong Initial Lappet Height Setting:- Correct Initial Lappet Height Setting (2 d + 5mm)
6. Improper selection of ABC Ring dia: - Proper selection of ABC Ring dia (equal dia of Ring dia)
7. ABC Ring height variation at Cop Initial stage:- Standard ABC Ring height variation at Cop Initial
stage
8. Ring rail Play:- No Ring rail Play
9. Too much dia of Rings:- Optimum dia of Rings (Spindle blade height / 4 )
10. Wrong Speed pattern at initial stage:- Correct speed of Ring rail Movement
------------------------------------------------------------------------------------------------------------
Mr.Su.Bhaskaran, Sidhaarth Exports P Ltd, Annur, Tamilnadu
Higher tension due to finer Traveller i.e. Correct Traveller No. to be selected to avoid excess
ballooning at cop bottom stage.
Spindle to lappet height setting should be optimized i.e. (30mm) the yarn should not rub the cop tip,
and the balloon should not bigger than the gap between the two separators
The winding angle ratio should be optimum
Ring rail speed i.e. winding length should be optimum for concern Count.
Pulling angle should be great than 30deg.
Selection of Ring tube dia with respect to the Ring dia.
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Mr.A.Senthilkumar, FM, Ganappathy Spinners, Vellakovil, Tamilnadu
Reason: Improper selection of Ring Traveller (i.e. Lighter Traveller) caused the end breakage in cop
bottom stage.
Remedies: We can use heavier Traveller to avoid the over ballooning & breakages. Adjust the
distance of lappet hook to spindle height setting depending upon the ballooning.
-------------------------------------------------------------------------------------
Mr.V.Sivasankar, Spinning Master, Raju Spinning Mills (P) Ltd., Rajapalayam, Tamilnadu
Reason for high end breakages at cop Bottom side
1. Wrong Traveller selection
2. Improper lappet& ABC ring height setting
3. Low outer diameter of empty tube on bottom side
4. Poor single yarn strength i.e. high cv value and also having poor csp.
5. Improper speed on (i.e. High speed ) cop bottom area .
6. Poor maintaining of RH%.
7. More distance between Ring & traveller clearer setting
Due to the above reasons for high end breakages are taking place at cop bottom.
------------------------------------------------------------------------------------------------------------
Mr.SP.Ravichandran, General Manager, Balaji Spinning, Aska, Orissa
Reasons for higher end breakages in cop bottom stage in spinning and remedies to control the same.
1. Proper selection of ring traveler with respect to ring life.
2. Evenness of the roving material
3. Spinning cop empties vs spindles for proper seatment.
4. Proper training to labours for stopping the spindles or
The empties will be disturbed and unnecessary end breaks in longer running.
5. Spindle tape condition and its life.
6. Improper selection of start up speeds. And gradually speed increase at bottom
position.
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Mr.Vinay Srivastav, DGM (Technical), Cheema Spintex Llimited, Lalru, Punjab
The three basic reasons for higher end breakages in cop bottom stage in spinning,
1. Improper selection of ring Traveller
2. Improper setting of ABC ring & lappet hook
3. Incorrect Sp.Speed pattern
Remedies point wise:
1. Use heavier ring Traveller
2. Proper gauge setting of ABC ring & lappet hook, Height setting of lappet hook to be corrected
3. Optimize speed pattern.
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Mr.K.Sudhakar, Manager, Santhose Spinning Mills, Coimbatore, Tamilnadu
Reasons: High winding tension due to improper winding angle between Ring and Traveller. Higher
spindle speed at initial stage, heavier traveller, poor ring, lappet and ABC centering, insufficient T/
M, improper height setting between empties top to lappet hook.
Remedies: Winding angle should be maintained from 30 to 34 degree, i.e empties Dui should be
selected according to ring dia. optimum speed and T.M to be selected at initial stage, according to
the raw material. Ring, ABC rings, spindles to be set perfectly with respect to each other, balloon
should not touch the empties top at any stage.
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Mr. S.Senthil Kumar, Manufacturing Manager, Thambbi Modern Spinning Mills, salem, Tamilnadu
Excessive yarn tension & ballooning are the main reason for higher breakages, particularly at cop
bottom.
I. Excessive yarn tension could be due to,
1. Selection of heavier traveler
2. In-adequate combination of ring: tube height ratio. It should be 1:5, higher the tube height
than recommendation results more initial breaks because the yarn touches the nose of the
empties
3. Improper concentric of lappet eye, spindle, and ring & Anti balloon rings
4. Excessive initial spindle speed
5. Improper cop bottom shape. I.e., Higher cop dia. Optimum cop dia should be = ring dia – 3mm
II. Higher yarn ballooning could be due to,
1. Selection of lighter traveler
2. Too high initial lappet height from top of the ring tube (Optimum – Ring dia + 2-3mm)
--------------------------------------------------------------------------------------------------------------
Mr.S.Vasudevan – FM & Mr.B.Rajkumar – ASM, Mahendra Spinning Mills (P) Ltd, Navakkarai,
Tamilnadu
Reasons for more breakages at cop bottom.
1. Wrong Selection of Traveller (too heavy or too light)
2. Improper ring centering and spindle gauge.
3. Improper Height of lappet hook to ring tube.
4. Excess spindle speed at bottom stage.
Remedies.
Proper selection of Traveller, correct ring centering, correct lappet height setting. Optimum
spindle speed at cop bottom.
--------------------------------------------------------------------------------------------------------------
Mr.S.Ramakrishnan, SM, Sri Rajalingam Tex, Vellakovil, Tamilnadu
Improper ballooning formation. Ballooning should touch the top of the paper tube and chase length
is very low and spindle speed is higher they will lead more breaks
Spindle speed to reduce 20% than the normal speed and at any cost Balloon should not touch the
top of the plastic tope (i.e. 2 times of top of the tube dia +5min to maintain)
---------------------------------------------------------------------------------------------------------------
Mr.V.Kalaiarasu, ASM, Mehala Carona Textiles (P) Ltd, Gobichettipalayam, Tamilnadu.
The reason for speed pattern improper, Wrong choice of Traveller no, Lappet height setting
variation, Lappet rail lifting improper, Chase length variation, Base running time ring rail up and
down motion speed high are few important reasons for higher end breakage in cop bottom stage in
spinning. If you rectify the above, breakage rate will reduce.
------------------------------------------------------------------------------------------------------------
Mrs. D.Jagathambal, SM, Thanigaivelan Spinning Mills Ltd., Annur, Tamilnadu
Cop bottom stage end breakages occurs due to use of low G/tex cotton, shore hardness of the top
rollers, Top arm pressure applied type of traveler, constant drive motors lack of control of
temperature and humidity.
To control with gradual speed motor drive, better cotton, combing or higher twist insertion RH55%
and temperature about 80°F.
-------------------------------------------------------------------------------------------------------------------------------
Mr.S.Karthikeyan, SM, Shree Raam Mills, Gobichettipalayam, Tamilnadu
Reason for higher end breakage in cop bottom stage in spinning frame lappet to Ring rail distance
high level for cop bottom stage so ballooning form high, this ballooning form create yarn tension
higher this tension is form to end breakages in higher for cop bottom stage.
Remeties
(i) First step ring rail to lappet distance reduce
(II) Correct selection for ring traveller
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Mr.S.Muthumanikam,FM,AKCT Chidambaram Cotton Mills (P) Ltd, Thiruvannamalai, Tamilnadu
The distance between lappet eye and ring is higher at bottom stage. That is making bigger balloon
and higher tension. Higher yarn tension creates higher end breakage.
REMEDIES:
1. Minimum size and Good condition of lappet eye according to the count.
2. Optimum distance between ring tube and Lappet eye.
3. Optimum Ring traveler number to control the balloon size at bottom stage.
4. Ring Frame must be provided with Anti balloon Control ring.
-------------------------------------------------------------------------------------------------------------------------------
Lean Cops in Spinning Series - www.lrtindia.com
This Interesting Article found at www.lrtindia.com from its various readers. I give collectively. The Credit goes to www.lrtindia.com and textile point appreciates their efforts in helping the global textile community.
Mr.R.Srinivasa Rao, General Manager, SPS Textiles & Industries Ltd, Annavaram,
Andhra Pradesh
If yarn breaks several numbers of times in one particular spindle, the cop made on this spindle
looks deshaped and appears lean due to low yarn content on the cop. This is called as lean cop.
The reasons are
1) Loaded Traveller running on the ring
2) Worn out rings
3) Wobbling spindles
4) Improper ring centering/spindle gauging
5) Cracks in the apron
6) Less TPI in roving
7) Burrs in the inner surface of lappet hook
8) Burrs on the separators
9) Missing spacer
10) Loosely fit empty tube on spindle
11) Close Traveller clearer setting
12) Wrong Traveller running for that particular ring
13) Thick places and thin places in the roving
14) Loose roving guide
15) Lack of enough quantity of oil in the bolster of spindle
16) Improperly set lappet hook
17) Traveller burn outs
18) Improper following of following traveller change schedules
19) Bobbin holder not rotating properly, etc,
---------------------------------------------------------------------------------------------------------------------
Mr.B.Shanmugakumar, Spinning Manager, PT. Gokak Indonesia, Bogor, Indonesia
Definition: Lean cops in spinning nothing but “Crippled cops effect” The cops which are
produced by yarn with higher degree of very frequent breaks causing very lesser in diameter
spinning cops.
Reasons:
1) When current spinning tension in the spinning process is higher than the current
yarn strength. – Higher yarn tension
2) Traveler loading.
3) Too closer or too wider traveler clearer setting both will cause higher yarn tension.
(Closer setting - traveler touching the clearer and wider setting - more Travellers
loading)
4) Improper gauging of ring, lappet and ABC centering, which cause tension variation.
5) Wrong selection traveler type and no.
6) Running at very high speeds with poor department climatic condition.
7) Poor fibre lubrication.
8) Front top roller groove formation or eccentric top roller.
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Mr.R. Krishnamoothi, G.M (Tech), Raju Spinning Mills Ltd, Unit –A, Rajapalayam.
Lean cops: On a spinning machine after doffing, all the cops must be of Uniform diameter,
shape and the weight of individual cops must be within the tolerance of minus 3% of the mean
average. Those exceed the weight tolerance and also have irregular (some times uniform)
diameter and shape are called lean cops.
Reasons
1. High end breaks above 15 per 100 spindle hours. Because of
a) Improper selection of mixing.
b) Incompatible mixing of cotton varieties.
c) High trash content.
d) High short fibre content.
e) Poor cleaning efficiencies in Blow Room and Carding.
f) Poor Processing efficiencies, Poor mechanical conditions of machinery and irregular
replacement of consumables like spindle tapes, aprons, cots, ring and Travellers
g) Last but not the least improper house keeping.
2. Non Uniform roving having high roving count cv percentage i.e. above 3%
3. Roving with stretch percentage beyond 2.5%.
4. Poor reel mechanical conditions in spinning like height of reel, height of roving guide rods,
poor bobbin holders.
5. Specific reasons for lean cops on specific spindles
Mechanical Conditions of rings, Travellers, clearers, clearer settings, lappet eye, drafting zone
conditions worn out tapes, bobbin hold
-----------------------------------------------------------------------------------------------------------
Mr.D.Ramkumar, Factory Manager, Pongalur Spinning Mills (P) Ltd, Pongalur
Lean cops means the cop build is not uniformly build up compared to other cops from the frame
and having less weight. The reason for the formation of lean cops is frequent breaks in spinning
that means breaks occurred in every patrolling of the sider.
REASONS:
MIXING:
1. Wide variation of staple length mixed in the same mixing.
2. Wide variation of micronaire values of cotton mixed.
3. Wide variation of fibre strength mixed in same mixing.
4. Homogenous blending is done in mixing and blow room.
PREPARATORY
1. Excessive variation in top roll pressure in draw frame.
2. Fluted roll setting in draw frame is not optimum.
3. Twist is less in simplex or twist is not inserted properly in simplex due to absence or damaged
false
Twister and less no. turn in flyer finger
4. Excessive creel stretch in simplex.
5. Top rolls damages in simplex.
SPINNING
1. Damaged rings.
2. Spindle out of centre with ring & lappet
3. Ring rail jerking
4. Traveller clearer settings are very closer.
5. Top rolls damages.
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Mr. A.Thanikachalam, Freelance Consultant, Rightspun Cotex India Pvt. Ltd.,
Coimbatore.
Lean Cops: A cop that fails to build up, due to frequent and repeated end breaks in a particular
spindle position in a ring frame is identified as a lean cop.
Causes for lean cops formation are –
1. Feed roving finer,
2. Soft twisted roving
3. Roving without stretch control at build in simplex
4. Rusted creel guide rod,
5. Improper creel settings causing excessive stretch at feed,
6. Worn out components such as bobbin holders, aprons, lappet hook, rings,
7· Wobbly spindles,
8. Damaged roving inlet guide,
9. Damaged cots,
10. Missing inlet guide, aprons,
11. Lappet hook misalignment to the spindle
12. Traveller loading
13. Eccentric spindle position in relation to ring
14. Serrated separators
-----------------------------------------------------------------------------------------------------------
Mr.K.Sambasiva Rao, Genaral Manager, Nandi Vardhana Textile Mills Pvt. Ltd, Guntur,
Andra Pradesh
Lean cops: Half standard cops are called lean cops (lesser weight than the standard weight).
Reasons for lean cops:
1. Due to abnormal breakages of particular spindles
2. Spindle wobbling
3. Worn out Ring
4. Roving bobbin hank variation / unevenness
5. Wrong combination of ring and Traveller
6. Wrong ring centering
7. Fine hank roving bobbin
8. Folding of bottom apron
9. Top roller arbour bearing worn out
10. More Travellers fly
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Mr.R.Kuppuraj, General Manager, PV Spinning Mills India P Ltd, Sathyamangalam
Lean cops means, the cops found lean and with lesser weight than the other cops in the same
ring frame.
The well possible causes for Lean cops are:
(1) Singles found in rove.
(2) Improper bobbin holder rotation.
(3) Dislocation of back roving guide.
(4) Grooved or cut top rolls.
(5) Bottom roll flutes damage.
(6) Damaged or broken cradles.
(7) Incorrect or mixed spacer.
(8) Bottom apron fork embedded with rove and waste.
(9) Wrongly pasted skived aprons.
(10) Damaged or teared aprons.
(11) Aprons out of center.
(12) Wrong top roll setting in top arm zone.
(13) Low top arm pressure.
(14) Lack of greasing to top rolls.
(15) Top or bottom rolls bearing worn out.
(16) Grooved or dispositional or dislocated lappet hooks.
(17) Improper lappet hooks size.
(18) ABC ring dislocation or damage.
(19) Burnt ring traveller.
(20) Wrong traveller clearer setting.
(21) Traveller mix up.
(22) Travellers clinked with waste tufts due to flies.
(23) Spindle out of center.
(24) Damaged ring.
(25) Loose spindle tape or unsize spindle tape.
(26) Wrong spindle gauge and lappet gauge
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Mr.T.A.Shanmuga Sundaram, Mill Manager, Saravana Polythreads (P) Ltd.
Gobichettipalayam
Breakage frequently occurs in a particular spindle due to some reasons which remains a ends
down attending by the tender in his patrolling, lost its shape and seen like a puny sized is known
as lean cops. Lean cops are defect yarn having very low strength, higher imperfection and count
variation. Many reasons for formation of lean cops, repeated breakages in a specific spindle for
any one of the following reasons leads to lean cops.
1. Improper setting of spindle and lappet gauging is a main reason
2. Worn-out gears and keyway in the drafting.
3. Burrs in the rings and burnt out Traveller (Traveller change schedule overdue 2 r 3 days of
schedule period, where some Traveller gets burnt out and cause for more breakage.)
4. Grooved lappet hooks.
5. Lighter hank bobbin due to splitting of ends and chocking of flyers in the simplex.
6. Worn out spindle tapes and half tapes causes for more slippages in spindle speed and create
soft twisted lean cops.
7. Bottom rolls eccentricity.
8. Damaged apron and cots.
9. Worn-out bobbin holders creates more stretch and produce thin places in the yarn with
regular intervals which causes formation of lean cops
-----------------------------------------------------------------------------------------------------------
-
Mr.N.Subramanian, General Manager, Vindhya Spinning Mills, Srivillputhur
In ring frames, for the given standard of say 36MM, those cops having uneven diameter of
36MM and below throughout the cop build are called lean cops. Lean cops are mainly formed due
to higher end breakages of 3 and above per 100 spindle hours, resulting in delayed attending of
piecing by siders.
Ultimately, higher end breakages are taking place due to:
1. Poor quality of raw material having lesser bundle strength
2. Over spinning of yarn count
3. Unsuitable process parameters like higher draft, low TPI, unsized spacer etc.
4. Not maintaining ambient relative humidity of 55 to 56% resulting more overlapping
5. Not maintaining periodic maintenance schedule like spindles, lappet, ABC and pressure gauge
Setting
6. Not periodically replacing the essential spares like spindles, Rings, Travellers, lappet, drafting
element, cots and aprons.
7. Improper selection of Traveller and improper following of Traveller changing schedule
8. Improper selection and function of ratchet wheel and ring rail movement
9. Finally due to low piecing efficiency of 12 minutes and below by siders resulting in delayed
attending offend breaks causes lean cops
Conclusion: Because of higher end breakage rate due to poor quality of raw material, over
spinning of counts, negligence in periodical maintenance schedule/overhauling/replacement of
essential parts, RH variation, unsuitable process parameters, incorrect ratching and low piecing
rate, lean cops are formed.
-----------------------------------------------------------------------------------------------------------
Mr.K.Balaji Natarajan, Senior Manager, Chowdary Spinners Ltd, Tanuku, Andra
Pradesh
Lean Cop is defined as lesser diameter than expected diameter with respect to Ring Diameter
Guide lines for Cop Diameter:
1. Ring diameter minus 3 to 4 MM for medium and coarser counts
2. Ring diameter minus 2.5 to 3 MM for fine counts
Actual diameter to be set and maintained based on practical experience, but Traveller should
never touch the cop layer at ant stage. Lean cops leads to low cop content and more hairiness
due to higher yarn stretch.
Reasons for formation of lean Cops:
1. Poor Ring centering: At least once in 6 months centering to be checked and corrected
2. Lappet hook centering: It should be center to ring and spindles, to be checked once in
6 months
3. Poor selection of ratchet wheel
4. Very closer Traveller clearer setting: It will leads to more end breakage and more
Hairiness due to Traveller loading, which should be 0.2 to 0.3 MM between Traveller
To clearer
All the above leads to more breaks (which reduces no. of coils per inch), poor balloon (which
gives stretch & yarn breaks), rubbing the yarn to closer Traveller clearer setting (which adds
more hairs, weak places & breaks)
-----------------------------------------------------------------------------------------------------------
-
Ms.V.R.Mallika, Mr.D.Senthilkumar & Mr.T.Jagadeesan, Technical team, Divya Prabha Spinning
Mills, Kinathukadavu, Pollachi
Reasons for Lean Cops in Spinning:
1. Damaged top & bottom aprons.
2. Grooved cots.
3. In correct cradle position.
4. High or low top arm pressure.
5. Worn out spacers.
6. Nose bar bend.
7. Eccentric top & bottom roller clearers.
8. Damaged top & Bottom clearers
9. Traverse motion defect.
10. Improper working of bobbin holder
11. Shifting of bottom fluted rollers.
12. Improper roving / yarn path.
13. Rust formation in creel rod & guide rod.
14. Lappet and spindle gauge improper.
15. Aged ring Travellers.
16. Wrong selection of ring Travellers.
17. Aged rings.
18. Worn out spindle buttons.
19. Improper seating of empties.
20.Spindle tape loose, improper working of jockey pulley.
21. Improper tape sticking methods.
22. Improper Traveller gauge setting.
23. Uneven hank bobbin.
24. Untwist portion in bobbin.
25.Spindle wobbling.
-----------------------------------------------------------------------------------------------------------------------
Mr.L.Narayana Prasad, Senior Manager-Quality, GHCL, Unit-Shree Meenakshi
Mills,Paravai
Definition of Lean cops: The deformed shape cops
Reasons for Lean cops:
1. Delayed piecing of broken yarns leads to uneven cop formation in spinning.
2. Repeated breaks in some spindles are one of the main reasons for random uneven cop
formation in spinning.
3. With increase in spindle speed, Traveller may be unbalanced on the ring flange on
account of centrifugal force, yarn pull and yarn tension resulting in higher breaks and
lean cop formation.
4. Lean Cops are due to incorrect ratchet wheel teeth and improper activation of ratchet
pawl.
5. Steps formation on the cops is due to defective builder cam or due to elongated chain.
6. Bottle shaped cops are due to defective apron movements and damaged aprons.
7. Improper selection of Traveller according to count, spindle speed and rings, Traveller
clearer setting, lappet eye and spindle centering to ring, jerky movement of ring rail.
8. Uneven ring rail load compensation, stuck up in ring rail movement
9. Ratchet pawl spring failure, improper selection of ratchet wheel
10. Ring frame running at different speed than selected speed and improper seating of
empties on the DUI.
11. Wrong selection of building motion related parameters like lifter combination, ratchet,
ring rail leveling and jerky combination.
12. Chase length not correlating with ring rail, improper allocation of spindle speed step,
uneven up and down movement of ring rail.
---------------------------------------------------------------------------------------------------------------------------
Mr.S. Chandrasekaran, Factory Manager, Jayanachiar Textile Mills (P) Ltd.,
Rajapalayam
DEFINITION AND FORMATION OF "LEAN COPS" IN RING SPINNING:
Lean cops in Spinning Means as in the name itself "Lean" in shape when compared with other
cops of the same Ring Frame. Frequent & periodic end breakage is the main reason for lean cops.
Few spindles of the Ring frame which are called 'Rogue' spindles producing lean cops. Without
knowing the frequency of breaks in a particular spindle, the piecer is going on piecing the broken
end in his every piecing round. As the builder motion is in its action, shifting the ring rail
upwards in every ratching irrespective of running of ends or not, the good running spindles
producing good shape of cops and the frequent breaks incurred spindles producing 'lean cops'.
There are so many reasons for frequent spindle breaks.
1. Spindle out of centre
2. Worn out Rings
3. Improper or heavier Ring Traveller.
4. Damaged / Poor condition of Aprons.
5. Intermittent running of Roving out of the Aprons.
6. Improper rotation of cradle.
7. Damaged / Improper rotation of top roller cots.
8. Mix-up of lighter hank Simplex Bobbins also a reason for formation of lean cops.
-----------------------------------------------------------------------------------------------------------
-
Mr.R.Sekar, Factory Manager, Sri Saravana Spinning Mills Pvt.Ltd, Vedasandur,
Dindigul
Lean Cops: The cops which are thinner in size and are not having the desired cop diameter is
called lean cops (Desired cop diameter = Ring diameter -3 to 4mm)
Reasons for formation of lean cops
1. If lean cops are observed on entire machine, the reason could be wrong selection of
ratchet wheel / wrong selection Traveller number and profile / wrong selection of
spacer.
2. If lean cops are observed only in a section of spindles , the reasons could be
Ring rail displacement, Lappet rail displacement or damaged pressure hose.
3. If lean cops are observed randomly or in a particular spindle , the following point to
be considered,
More and repeated end breaks is the main reason for lean cops and the possible causes for the
breaks are given below:
a) Improper Ring/Spindle/lappet / ABC ring centering
b) Front roll Eccentricity and Spindle wobbling
c) Damaged cots / Aprons / Rings / Travelers and improper traveler clearer
setting.
d) Without apron or Spacer missing
e) Hank variation in roving / Un drafted roving
f) Poor top arm loading / Low air pressure
g) Spindle tape slip / Damaged spindle tape
--------------------------------------------------------------------------------------------------------------------------
Mr.S.K.Jindal, General Manager , Ginni International Ltd, Neemrana, rajasthan
Definition: The cops in which the yarn breaks repeatedly due to one or the other reasons are
called lean cops or sick bobbins.
Reasons for their formation:
1. Undrafted roving due to improper (lesser) spacer size, higher t m in roving, lesser top arm
pressure, higher moisture in department etc
2. Wrong ring Traveller (too heavy or too lighter)
3. Eccentric spindle
4. Ring not centered
5. Lesser speed of spindle due to bolster defective or fly in the brake
6. Spindle tape running above wharves dia leading to lesser rpm of spindle
7. Defective top cot, aprons etc
8. Singles in roving (finer roving than should be)
9. Traverse of roving not proper (going out of cot width)
10. Lappet hook, ABC ring not centered
11. Excessive thick & thin places in roving
12. Repeated ring Traveller fly off from spindle
13. Damaged ring
-----------------------------------------------------------------------------------------------------------
-
Mr. Tammisetti Krishna, Mill Manager, Balarama Krishna Spinning Mills (p) Ltd,
Guntur, Andra Pradesh.
Lean Cops: The Cops having lesser in size compared to other cops are called lean cops. The
reasons are
1. More breakage or repeated breakage spindles due to spindle, lappet and ABC ring centering
problems and creating lean cops.
2. Very less space between bottom and top aprons (i.e. usage of very thin spacer).
3. Usage of lighter Travellers
4. Soft roving bobbin i.e. sliver split at roving creel.
5. Roving mix-up i.e. usage of finer hank roving.
6. Top apron cradle roller touches to front top roller.
7. More front offset top rollers problem.
8. Wrong selection of Travellers, ratchet and spindle speed.
9. Cradle damages, Top & Bottom aprons absence or damage, Spacer missing and more creel
breakages etc causing lean cops.
10. Damaged ring and damaged lappet hooks create lean cops.
-----------------------------------------------------------------------------------------------------------
-
Mr.K.Ravikanth, Manager-QA, Suryalakshmi Cotton Mills Ltd, Amanagal, Andra
Pradesh
Lean Cops having yarn content or diameter lesser than the specified are called lean cops. In
general yarn content per cop will be around 50 – 60 gms, expected cop dia = (ring diameter -
3mm). Lean cops are the indication of poor maintenance / worker's bad practices.
With the introduction of auto levelers at draw frames, finer count problems are totally
eliminated but one must take care of sliver peel off at simplex machines which not only causes
lean cops but also thin faults and higher count CV %.
Normally, spindles having the problem of repeated end break will produce lean cops. Wrong
selection of ratchet after a count change and handling of ratchet by the ring frame tenders
during the normal course of doff running can cause total ring frame lean cops.
Any way, an immediate attention is need to be paid towards the spindles producing lean cops as
the most of the lean cops will be having yarn of inferior quality.
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Mr.A.Nandhakumar, Spinning Master, GMR Spintex Pvt Limited, Adilabad
Lean Cops" means improper build up or improper dia of cops produced in ring frames. It’s
because of the following reasons.
1. Improper selection of Ratchet wheel leads to lesser diameter in cops.
2. Improper selection of Spacer and missing of Spacer causes lean cops" randomly.
3. Un draft due to lesser top of pressure, missing of spacer and higher TPI in roving causes
lean cops
4. Improper centering of Bottom middle aprons, Improper centering of top arms leads frequent
end breaks causes "lean cops".
5. Slipped spindle leads frequent breaks that cause "lean cops".
6. Damaged bottom aprons, Improper centering of ring, ABC ring and lappet gauges leads
repeated breaks causes "lean cops".
7. Bobbin Exhaust should be filled in correct time unless that also causes "lean cops".
To avoid "Lean cops" preventive maintenance, on- line checklist will be very useful. If Ring data
installed in ring frame its a nice tool to short out the repeated breaks spindles that avoid lean
cops.
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Mr.K Pothiraj, GM-Business Development, Indorama Synthetics (I) Ltd, Coimbatore
A cop of a ring frame has three distinguishable parts viz., lower curved base, cylindrical middle
and a conical tip. A lean cop is one which does not meet the above characteristics of a cop and
has lower cop weight.
Lean cops are due to very fine count, excessive breakages on a particular spindle, very high
chase length and smaller ratchet wheel of ring frame builder motion. Eccentric spindles, bobbins
and none centering of spindles with rings and lappet contribute to higher breaks leading to lean
cops. Operators not attending to breakage in time and not creeling the bobbins in time after
bobbin exhaust also will lead to lean cops. Wrong selection of shaper wheel and or teeth per
stroke is also a reason for lean cops.
It is advisable to maintain cop diameter 2 to 3 mm less than the ring diameter to ensure smooth
running of Traveller. The chase length must be 15% more than the ring diameter for achieving
good cop shape. Winding length per cam revolution should be around 4 meters. Selection of
number of actuating pins in the heart cam and number of teeth in the ratchet should be done
depending on the count processed. Balancing of ring rail and lappet should be proper to avoid
lean cops.
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Mr.S. Ramakrishnan, Spinning Master, Sri Rajalinkam Tex, Vellakovil
Lean cops means Cop diameter is very low and shape is irregular i.e. called lean cops.
The following reasons for producing lean cops
1. Bobbin Hank variation is high.
2. Bobbin holder rotation is not free
3. Cracked or damaged cots are used
4. Spindles out of centre
5. Cracked or grooved Lappet Hook
6. Heavier Traveller usage
7. Top and Bottom Apron condition is poor i.e. grooved and holes
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Mr.P.Sivasamy, General Manager, Sadhana Spinners Limited, Kangeyam
Lean Cops: Because of frequent breaks, cops appear lean when compared to normal cops. Lean
cops weigh around 70% lower than normal cops.
Reasons for formation of Lean Cops
1. Running without or unsuitable spacer
2. Flies accumulation on Travellers
3. Nice roving
4. Damaged spindle or improper spindle gauge
5. Running without ABC rings
6. Damages in cots and aprons
7. Low pressure in Top arm.
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Mr.C.Sivakumar, Factory Manager, Sri Vasudeva Textiles Limited, Thekkupalayam,
Coimbatore
Lean Cops: Uneven cop diameter formation and low cop content
Reasons for Lean Cops in Spinning
1. Repeated Breaks: Mainly due to cots, apron damage, spindle out of centre. Narrow Traveller
clearer setting, lappet hook damage and improper centering
2. Fine Counts: Due to sliver peel off in simples (sliver splitting)
2. Wrong selection of Travellers: Too heavier and lighter Traveller Leeds frequent and multiple
breaks)
4. Traveller burn-out
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Mr.S.Murugeswaran, Production Manager, Shri Renuga Textiles Limited, Theni,
Tamilnadu
Lean cops are those which are not having standard cop content and creating more. Breaks in
winding department, various reasons are behind lean cops. They are classified as:
1. In efficient sider
2. More breaks in spinning due to poor centering, worn-out spindles, rings
3. Improper feed bobbin
4. Unmatch of Traveller in spinning
5. Improper RH inside the department
6. High apron groove or damaged apron running
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Mr.K.Thirumaran, Factory Manager, Alpine Knits India Pvt Ltd, Palladam, Coimbatore
Improper build and repeated breaks Spindles make lean cops in spinning. This is also called as
fancy or film fair award cops.
Reasons are:
a) Improper Combination of ratchet & Pawl as well as winding length.
b) Undrafted ends and variation in feed bobbins.
c) Improper selection of Travellers & it's Clearance as well as used Travellers.
d) In correct setting of ABC, Ring, Lappet bar & Hook etc.
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Mr.P.Kungumaraju, Factory Manager, Ramani Textile Mills Pvt Limited, Avinashi
Lean cops are the unshaped cops from spinning machine because of the mechanical problem in
the spindles.
The major reason for the lean cops is the more breakage in the spindle. The reasons may be as
1) Jerk in the ring rail. 2) Ring damage.3) Poor ring or spindle centering. 4) Replacement of
Traveller with unsized Traveller 6) Traveller clearer setting too close .7) Worn out aprons. 8)
Insufficient top roller pressure. 9). Poor quality of the roving input. 10) .Improper fit of the
spinning empties. .Because of the above said reasons the breakage rate will increase and lead to
frequency of attending the breakage will increase. Failure in the building mechanism will also be
the reason for Lean cops.
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Mr.M.Gopala Krishnan, Factory manager, MLR Mills, Karuvalur, Annur
Cops produced in 20% to 40% lesser than ring diameter from spinning called as lean cops. Lean
cops are formed due to Improper Traveller selection , Improper ratchet selection , Higher
breakage rate , Improper ring centering , Improper tape selection and brake condition .
This is the reason for producing lean cops.
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Mr. V.Vadivelu & Mr. U.Selvam, Technical team, Eniya Spinwell, Coimbatore
Lean cops are defined as "the cops which is obstructed by normal spinning leads to repeated
breaks and seems to be lean". Insufficient top arm pressure, Improper spindle and lappet
alignment, Bobbin holder struck up, damages in cots, aprons, roving guides, flutted rollers,
lappet hook and separators will led to lean cops.
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Mr.K.Kannan, Spinning Master, Sri Dhanalakshmi Sizing & Spinning Mill Limited,
Karumathampatti
A cop is having low content of yarn and improper shape than the regular cops are called lean
cops. Also, having low CSP and Quality defects. The main reason for formation of lean cops is
repeated and unnecessary yarn breaks in a particular spindle. Higher yarn breaks due to
improper selection of Traveller number and profile. Poor condition of rings and ring centering is
not good. Spindle wobbling is high due to damaged bolsters. High H1 faults due to singles in
roving stage and high stretch of roving in simplex and spinning stages. Also, damaged cots and
aprons.
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Mr.R.Varadaraju, Manager-QC, Sri Ramakrishna Mills Limited, Coimbatore
Lean cops are defined as cops with much lesser cop content and cop diameter than regular cops
by lesser than 25%. Lean cops are produced due to very high end breakage rate in those
spindles due to one or more of the following reasons.
Spindles out of centre worn out rings frequent wear out of traveller, traveller ply-off due to
worn out ring/traveller (or) miss match of ring and travellers, worn out/cracked aprons/cots,
cots, unsteady rotation of top rolls, uneven or very fine or low twist or high twist Simplex
bobbins etc.
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Mr.B.Rajkumar, ASM, Mahendra Spinning Mills (P) Limited, Navakarai, Coimbatore
Reduced diameter of normal cops (Below 75%) caused by repeat breaks by particular spindle
and the cops have lesser yarn content with huge piecing called Lean Cops. Faulty Spindle,
Spindle out of Centre, Lappet away from centre, cots damage, Top or Bottom roller
eccentricity, irregular movement of apron, over traverse of roving, Spacer missing, non - free
rotating of bobbin holder, faulty bobbin from simplex are some reason for formation of Lean
Cops.
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Mr.S.Sivaperumal, Factory Manager, Sree Koppammal Spinning Mills, Aruppukottai
Lean Cops are the cops having considerably lesser diameter through out its lift. (Standard
diameter may be 1MM lesser that Ring diameter. The reasons may be the following:
1. Wrong selection of retched wheel, i.e., with lesser teeth
2. Moving of more number of teeth in ratchet by pawl for each ring rail movement
3. Long run finer hank roving bobbins in the ring frame, which are produced by mistake in
simplex
4. Roving guide chock with fluff, apron chock with fluff and faulty bobbin holders
5. More or frequent breaks in some spindles due to some reasons
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Mr.S.Sripathi, Factory Manager, Vajram Spinning Mills (P) Limited, Rajapalayam
Under diameter of cops than the normal build up of cops to the ring diameter
throughout it formation is called lean cops.
Abnormal variation in micronire value from mixing to mixing. Spinning of finer count than the
normal count. Wrong selection of ratchet wheel. Wrong setting of ratchet movement. Singles
emerging from Draw frame and to the roving stand, worn-out rings and unsuitable Traveller,
spindle out of centre, close setting of Traveller cleaner and other causes leading to frequent
breaks.
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Mr.K.Senthilkumar, Factory Manager, Raju Spinning Mills Ltd, B-Unit, Srivilliputhur
Lean cops are seeing entirely different in diameter and shape from regular spinning cops. Lean
cops are caused by variations in spindle and lappet gauges and improper alignment in cradle
setting and in spindles with repeated breakages. Lean cops may come by using worn out
Travellers by the workers bad practices of taking the Travellers underneath the spinning m/c.
Further hank variation in roving may produce lean cops.
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Mr.S. Sannkarabagam, Mill Manager, Pariyur Amman Spinning Mills, Gobichettipalayam
Lean cop is nothing but finer count yarn than normal running count or other version smaller
diameter Cops than normal size of the cops. This is mainly produced due to singles in roving
Bobbins. Due to spindle out of centre this type of Cops will be produced. Due to worn out
Traveller this will be produced. Due to wrong ratchet wheel selection these types of cops will be
produced.
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Mr.Mahendra V. Bhoyar, GM-Technical, Bhandari Exports Ind. Ltd, Lalru, Punjab
Lean Cops: Ideally Ring Frame cop diameter should be less by 4-5 % than Ring diameter, if cop
diameter is lesser than this as compared to Ring diameter is called lean cops.
Reasons are finer roving than normal roving hanks used for particular counts. Apart from this,
excessive breakages at particular spindle are main cause of formation of lean cops. The reason
for excessive breakages of yarn may be due to worn out rings, Travellers, improper rings gauge
eccentric spindles, worn out ABC ring, lappet hooks, damaged cots/Aprons, missing spacers
excessive, stretch to rove on R/F creels, Improper top roller pressure etc.
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Mr.K.S.Sankar, AGM(Maint), GTN Industries Ltd, Nagpur
Lean cops are produced from the ring spinning machines; ring frame cop diameter which is not
matching with adjacent spindle (or) the entire ring frame is called as Lean cops. Normally in my
experience, cop diameter which is less by 10% and above can only be visible as a lean cop, when
we check the quality parameters it will not match with normal cop such as, lower CSP & RKM,
more hairiness, high IMP and higher count CV%, etc
Major reason for formation of lean cop is due to , ring Traveller is heavier by 3 to 4 numbers
than the adjacent spindle ,wear out ring Traveller, closer r/t clearer setting than recommended
ring flange damages & wear out, more end breaks , groove and cut formation in the lappet eye
and roving hank fed is finer than requirement, etc.
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Mr.T. Ravi, Dy.Manager, Super Spinning Mills Limited, C-Unit, Karur
Lean cops are due to in correct ratchet wheel teeth and improper activation of ratchet pawl. In
accuracy in achieving the perpendicular angle of pocker with respect to spindle beam. Bottle
shaped cops are due to defective apron movements and damaged aprons. Steps formation on the
cops is due to resistance of ring rail at one point either due to defective builder cam or due to
elongated chains are having correlation with lean cop’s formation in spinning.
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Mr.S.Senthilkumar, Manufacturing Manager, Thambbi Modern Spinning Mills Ltd,
Salem
Lean Cops: Cops which are produced with under diameter or built with very high tension or with
repeated breaks are known as LEAN cops.
Reasons:
1. High yarn tension due to improper centering of Spindle, Ring, ABC rings & Lappet guide
2. High yarn tension due to the selection of HEAVIER travellers
3. Repeated breaks in particular spindle due to various reasons
4. Production of wide difference finer count than normal yarn due to wrong bobbin feed.
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Mr.R.Srinivasa Rao, General Manager, SPS Textiles & Industries Ltd, Annavaram,
Andhra Pradesh
If yarn breaks several numbers of times in one particular spindle, the cop made on this spindle
looks deshaped and appears lean due to low yarn content on the cop. This is called as lean cop.
The reasons are
1) Loaded Traveller running on the ring
2) Worn out rings
3) Wobbling spindles
4) Improper ring centering/spindle gauging
5) Cracks in the apron
6) Less TPI in roving
7) Burrs in the inner surface of lappet hook
8) Burrs on the separators
9) Missing spacer
10) Loosely fit empty tube on spindle
11) Close Traveller clearer setting
12) Wrong Traveller running for that particular ring
13) Thick places and thin places in the roving
14) Loose roving guide
15) Lack of enough quantity of oil in the bolster of spindle
16) Improperly set lappet hook
17) Traveller burn outs
18) Improper following of following traveller change schedules
19) Bobbin holder not rotating properly, etc,
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Mr.B.Shanmugakumar, Spinning Manager, PT. Gokak Indonesia, Bogor, Indonesia
Definition: Lean cops in spinning nothing but “Crippled cops effect” The cops which are
produced by yarn with higher degree of very frequent breaks causing very lesser in diameter
spinning cops.
Reasons:
1) When current spinning tension in the spinning process is higher than the current
yarn strength. – Higher yarn tension
2) Traveler loading.
3) Too closer or too wider traveler clearer setting both will cause higher yarn tension.
(Closer setting - traveler touching the clearer and wider setting - more Travellers
loading)
4) Improper gauging of ring, lappet and ABC centering, which cause tension variation.
5) Wrong selection traveler type and no.
6) Running at very high speeds with poor department climatic condition.
7) Poor fibre lubrication.
8) Front top roller groove formation or eccentric top roller.
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Mr.R. Krishnamoothi, G.M (Tech), Raju Spinning Mills Ltd, Unit –A, Rajapalayam.
Lean cops: On a spinning machine after doffing, all the cops must be of Uniform diameter,
shape and the weight of individual cops must be within the tolerance of minus 3% of the mean
average. Those exceed the weight tolerance and also have irregular (some times uniform)
diameter and shape are called lean cops.
Reasons
1. High end breaks above 15 per 100 spindle hours. Because of
a) Improper selection of mixing.
b) Incompatible mixing of cotton varieties.
c) High trash content.
d) High short fibre content.
e) Poor cleaning efficiencies in Blow Room and Carding.
f) Poor Processing efficiencies, Poor mechanical conditions of machinery and irregular
replacement of consumables like spindle tapes, aprons, cots, ring and Travellers
g) Last but not the least improper house keeping.
2. Non Uniform roving having high roving count cv percentage i.e. above 3%
3. Roving with stretch percentage beyond 2.5%.
4. Poor reel mechanical conditions in spinning like height of reel, height of roving guide rods,
poor bobbin holders.
5. Specific reasons for lean cops on specific spindles
Mechanical Conditions of rings, Travellers, clearers, clearer settings, lappet eye, drafting zone
conditions worn out tapes, bobbin hold
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Mr.D.Ramkumar, Factory Manager, Pongalur Spinning Mills (P) Ltd, Pongalur
Lean cops means the cop build is not uniformly build up compared to other cops from the frame
and having less weight. The reason for the formation of lean cops is frequent breaks in spinning
that means breaks occurred in every patrolling of the sider.
REASONS:
MIXING:
1. Wide variation of staple length mixed in the same mixing.
2. Wide variation of micronaire values of cotton mixed.
3. Wide variation of fibre strength mixed in same mixing.
4. Homogenous blending is done in mixing and blow room.
PREPARATORY
1. Excessive variation in top roll pressure in draw frame.
2. Fluted roll setting in draw frame is not optimum.
3. Twist is less in simplex or twist is not inserted properly in simplex due to absence or damaged
false
Twister and less no. turn in flyer finger
4. Excessive creel stretch in simplex.
5. Top rolls damages in simplex.
SPINNING
1. Damaged rings.
2. Spindle out of centre with ring & lappet
3. Ring rail jerking
4. Traveller clearer settings are very closer.
5. Top rolls damages.
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Mr. A.Thanikachalam, Freelance Consultant, Rightspun Cotex India Pvt. Ltd.,
Coimbatore.
Lean Cops: A cop that fails to build up, due to frequent and repeated end breaks in a particular
spindle position in a ring frame is identified as a lean cop.
Causes for lean cops formation are –
1. Feed roving finer,
2. Soft twisted roving
3. Roving without stretch control at build in simplex
4. Rusted creel guide rod,
5. Improper creel settings causing excessive stretch at feed,
6. Worn out components such as bobbin holders, aprons, lappet hook, rings,
7· Wobbly spindles,
8. Damaged roving inlet guide,
9. Damaged cots,
10. Missing inlet guide, aprons,
11. Lappet hook misalignment to the spindle
12. Traveller loading
13. Eccentric spindle position in relation to ring
14. Serrated separators
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Mr.K.Sambasiva Rao, Genaral Manager, Nandi Vardhana Textile Mills Pvt. Ltd, Guntur,
Andra Pradesh
Lean cops: Half standard cops are called lean cops (lesser weight than the standard weight).
Reasons for lean cops:
1. Due to abnormal breakages of particular spindles
2. Spindle wobbling
3. Worn out Ring
4. Roving bobbin hank variation / unevenness
5. Wrong combination of ring and Traveller
6. Wrong ring centering
7. Fine hank roving bobbin
8. Folding of bottom apron
9. Top roller arbour bearing worn out
10. More Travellers fly
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Mr.R.Kuppuraj, General Manager, PV Spinning Mills India P Ltd, Sathyamangalam
Lean cops means, the cops found lean and with lesser weight than the other cops in the same
ring frame.
The well possible causes for Lean cops are:
(1) Singles found in rove.
(2) Improper bobbin holder rotation.
(3) Dislocation of back roving guide.
(4) Grooved or cut top rolls.
(5) Bottom roll flutes damage.
(6) Damaged or broken cradles.
(7) Incorrect or mixed spacer.
(8) Bottom apron fork embedded with rove and waste.
(9) Wrongly pasted skived aprons.
(10) Damaged or teared aprons.
(11) Aprons out of center.
(12) Wrong top roll setting in top arm zone.
(13) Low top arm pressure.
(14) Lack of greasing to top rolls.
(15) Top or bottom rolls bearing worn out.
(16) Grooved or dispositional or dislocated lappet hooks.
(17) Improper lappet hooks size.
(18) ABC ring dislocation or damage.
(19) Burnt ring traveller.
(20) Wrong traveller clearer setting.
(21) Traveller mix up.
(22) Travellers clinked with waste tufts due to flies.
(23) Spindle out of center.
(24) Damaged ring.
(25) Loose spindle tape or unsize spindle tape.
(26) Wrong spindle gauge and lappet gauge
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Mr.T.A.Shanmuga Sundaram, Mill Manager, Saravana Polythreads (P) Ltd.
Gobichettipalayam
Breakage frequently occurs in a particular spindle due to some reasons which remains a ends
down attending by the tender in his patrolling, lost its shape and seen like a puny sized is known
as lean cops. Lean cops are defect yarn having very low strength, higher imperfection and count
variation. Many reasons for formation of lean cops, repeated breakages in a specific spindle for
any one of the following reasons leads to lean cops.
1. Improper setting of spindle and lappet gauging is a main reason
2. Worn-out gears and keyway in the drafting.
3. Burrs in the rings and burnt out Traveller (Traveller change schedule overdue 2 r 3 days of
schedule period, where some Traveller gets burnt out and cause for more breakage.)
4. Grooved lappet hooks.
5. Lighter hank bobbin due to splitting of ends and chocking of flyers in the simplex.
6. Worn out spindle tapes and half tapes causes for more slippages in spindle speed and create
soft twisted lean cops.
7. Bottom rolls eccentricity.
8. Damaged apron and cots.
9. Worn-out bobbin holders creates more stretch and produce thin places in the yarn with
regular intervals which causes formation of lean cops
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Mr.N.Subramanian, General Manager, Vindhya Spinning Mills, Srivillputhur
In ring frames, for the given standard of say 36MM, those cops having uneven diameter of
36MM and below throughout the cop build are called lean cops. Lean cops are mainly formed due
to higher end breakages of 3 and above per 100 spindle hours, resulting in delayed attending of
piecing by siders.
Ultimately, higher end breakages are taking place due to:
1. Poor quality of raw material having lesser bundle strength
2. Over spinning of yarn count
3. Unsuitable process parameters like higher draft, low TPI, unsized spacer etc.
4. Not maintaining ambient relative humidity of 55 to 56% resulting more overlapping
5. Not maintaining periodic maintenance schedule like spindles, lappet, ABC and pressure gauge
Setting
6. Not periodically replacing the essential spares like spindles, Rings, Travellers, lappet, drafting
element, cots and aprons.
7. Improper selection of Traveller and improper following of Traveller changing schedule
8. Improper selection and function of ratchet wheel and ring rail movement
9. Finally due to low piecing efficiency of 12 minutes and below by siders resulting in delayed
attending offend breaks causes lean cops
Conclusion: Because of higher end breakage rate due to poor quality of raw material, over
spinning of counts, negligence in periodical maintenance schedule/overhauling/replacement of
essential parts, RH variation, unsuitable process parameters, incorrect ratching and low piecing
rate, lean cops are formed.
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Mr.K.Balaji Natarajan, Senior Manager, Chowdary Spinners Ltd, Tanuku, Andra
Pradesh
Lean Cop is defined as lesser diameter than expected diameter with respect to Ring Diameter
Guide lines for Cop Diameter:
1. Ring diameter minus 3 to 4 MM for medium and coarser counts
2. Ring diameter minus 2.5 to 3 MM for fine counts
Actual diameter to be set and maintained based on practical experience, but Traveller should
never touch the cop layer at ant stage. Lean cops leads to low cop content and more hairiness
due to higher yarn stretch.
Reasons for formation of lean Cops:
1. Poor Ring centering: At least once in 6 months centering to be checked and corrected
2. Lappet hook centering: It should be center to ring and spindles, to be checked once in
6 months
3. Poor selection of ratchet wheel
4. Very closer Traveller clearer setting: It will leads to more end breakage and more
Hairiness due to Traveller loading, which should be 0.2 to 0.3 MM between Traveller
To clearer
All the above leads to more breaks (which reduces no. of coils per inch), poor balloon (which
gives stretch & yarn breaks), rubbing the yarn to closer Traveller clearer setting (which adds
more hairs, weak places & breaks)
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Ms.V.R.Mallika, Mr.D.Senthilkumar & Mr.T.Jagadeesan, Technical team, Divya Prabha Spinning
Mills, Kinathukadavu, Pollachi
Reasons for Lean Cops in Spinning:
1. Damaged top & bottom aprons.
2. Grooved cots.
3. In correct cradle position.
4. High or low top arm pressure.
5. Worn out spacers.
6. Nose bar bend.
7. Eccentric top & bottom roller clearers.
8. Damaged top & Bottom clearers
9. Traverse motion defect.
10. Improper working of bobbin holder
11. Shifting of bottom fluted rollers.
12. Improper roving / yarn path.
13. Rust formation in creel rod & guide rod.
14. Lappet and spindle gauge improper.
15. Aged ring Travellers.
16. Wrong selection of ring Travellers.
17. Aged rings.
18. Worn out spindle buttons.
19. Improper seating of empties.
20.Spindle tape loose, improper working of jockey pulley.
21. Improper tape sticking methods.
22. Improper Traveller gauge setting.
23. Uneven hank bobbin.
24. Untwist portion in bobbin.
25.Spindle wobbling.
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Mr.L.Narayana Prasad, Senior Manager-Quality, GHCL, Unit-Shree Meenakshi
Mills,Paravai
Definition of Lean cops: The deformed shape cops
Reasons for Lean cops:
1. Delayed piecing of broken yarns leads to uneven cop formation in spinning.
2. Repeated breaks in some spindles are one of the main reasons for random uneven cop
formation in spinning.
3. With increase in spindle speed, Traveller may be unbalanced on the ring flange on
account of centrifugal force, yarn pull and yarn tension resulting in higher breaks and
lean cop formation.
4. Lean Cops are due to incorrect ratchet wheel teeth and improper activation of ratchet
pawl.
5. Steps formation on the cops is due to defective builder cam or due to elongated chain.
6. Bottle shaped cops are due to defective apron movements and damaged aprons.
7. Improper selection of Traveller according to count, spindle speed and rings, Traveller
clearer setting, lappet eye and spindle centering to ring, jerky movement of ring rail.
8. Uneven ring rail load compensation, stuck up in ring rail movement
9. Ratchet pawl spring failure, improper selection of ratchet wheel
10. Ring frame running at different speed than selected speed and improper seating of
empties on the DUI.
11. Wrong selection of building motion related parameters like lifter combination, ratchet,
ring rail leveling and jerky combination.
12. Chase length not correlating with ring rail, improper allocation of spindle speed step,
uneven up and down movement of ring rail.
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Mr.S. Chandrasekaran, Factory Manager, Jayanachiar Textile Mills (P) Ltd.,
Rajapalayam
DEFINITION AND FORMATION OF "LEAN COPS" IN RING SPINNING:
Lean cops in Spinning Means as in the name itself "Lean" in shape when compared with other
cops of the same Ring Frame. Frequent & periodic end breakage is the main reason for lean cops.
Few spindles of the Ring frame which are called 'Rogue' spindles producing lean cops. Without
knowing the frequency of breaks in a particular spindle, the piecer is going on piecing the broken
end in his every piecing round. As the builder motion is in its action, shifting the ring rail
upwards in every ratching irrespective of running of ends or not, the good running spindles
producing good shape of cops and the frequent breaks incurred spindles producing 'lean cops'.
There are so many reasons for frequent spindle breaks.
1. Spindle out of centre
2. Worn out Rings
3. Improper or heavier Ring Traveller.
4. Damaged / Poor condition of Aprons.
5. Intermittent running of Roving out of the Aprons.
6. Improper rotation of cradle.
7. Damaged / Improper rotation of top roller cots.
8. Mix-up of lighter hank Simplex Bobbins also a reason for formation of lean cops.
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Mr.R.Sekar, Factory Manager, Sri Saravana Spinning Mills Pvt.Ltd, Vedasandur,
Dindigul
Lean Cops: The cops which are thinner in size and are not having the desired cop diameter is
called lean cops (Desired cop diameter = Ring diameter -3 to 4mm)
Reasons for formation of lean cops
1. If lean cops are observed on entire machine, the reason could be wrong selection of
ratchet wheel / wrong selection Traveller number and profile / wrong selection of
spacer.
2. If lean cops are observed only in a section of spindles , the reasons could be
Ring rail displacement, Lappet rail displacement or damaged pressure hose.
3. If lean cops are observed randomly or in a particular spindle , the following point to
be considered,
More and repeated end breaks is the main reason for lean cops and the possible causes for the
breaks are given below:
a) Improper Ring/Spindle/lappet / ABC ring centering
b) Front roll Eccentricity and Spindle wobbling
c) Damaged cots / Aprons / Rings / Travelers and improper traveler clearer
setting.
d) Without apron or Spacer missing
e) Hank variation in roving / Un drafted roving
f) Poor top arm loading / Low air pressure
g) Spindle tape slip / Damaged spindle tape
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Mr.S.K.Jindal, General Manager , Ginni International Ltd, Neemrana, rajasthan
Definition: The cops in which the yarn breaks repeatedly due to one or the other reasons are
called lean cops or sick bobbins.
Reasons for their formation:
1. Undrafted roving due to improper (lesser) spacer size, higher t m in roving, lesser top arm
pressure, higher moisture in department etc
2. Wrong ring Traveller (too heavy or too lighter)
3. Eccentric spindle
4. Ring not centered
5. Lesser speed of spindle due to bolster defective or fly in the brake
6. Spindle tape running above wharves dia leading to lesser rpm of spindle
7. Defective top cot, aprons etc
8. Singles in roving (finer roving than should be)
9. Traverse of roving not proper (going out of cot width)
10. Lappet hook, ABC ring not centered
11. Excessive thick & thin places in roving
12. Repeated ring Traveller fly off from spindle
13. Damaged ring
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Mr. Tammisetti Krishna, Mill Manager, Balarama Krishna Spinning Mills (p) Ltd,
Guntur, Andra Pradesh.
Lean Cops: The Cops having lesser in size compared to other cops are called lean cops. The
reasons are
1. More breakage or repeated breakage spindles due to spindle, lappet and ABC ring centering
problems and creating lean cops.
2. Very less space between bottom and top aprons (i.e. usage of very thin spacer).
3. Usage of lighter Travellers
4. Soft roving bobbin i.e. sliver split at roving creel.
5. Roving mix-up i.e. usage of finer hank roving.
6. Top apron cradle roller touches to front top roller.
7. More front offset top rollers problem.
8. Wrong selection of Travellers, ratchet and spindle speed.
9. Cradle damages, Top & Bottom aprons absence or damage, Spacer missing and more creel
breakages etc causing lean cops.
10. Damaged ring and damaged lappet hooks create lean cops.
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Mr.K.Ravikanth, Manager-QA, Suryalakshmi Cotton Mills Ltd, Amanagal, Andra
Pradesh
Lean Cops having yarn content or diameter lesser than the specified are called lean cops. In
general yarn content per cop will be around 50 – 60 gms, expected cop dia = (ring diameter -
3mm). Lean cops are the indication of poor maintenance / worker's bad practices.
With the introduction of auto levelers at draw frames, finer count problems are totally
eliminated but one must take care of sliver peel off at simplex machines which not only causes
lean cops but also thin faults and higher count CV %.
Normally, spindles having the problem of repeated end break will produce lean cops. Wrong
selection of ratchet after a count change and handling of ratchet by the ring frame tenders
during the normal course of doff running can cause total ring frame lean cops.
Any way, an immediate attention is need to be paid towards the spindles producing lean cops as
the most of the lean cops will be having yarn of inferior quality.
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Mr.A.Nandhakumar, Spinning Master, GMR Spintex Pvt Limited, Adilabad
Lean Cops" means improper build up or improper dia of cops produced in ring frames. It’s
because of the following reasons.
1. Improper selection of Ratchet wheel leads to lesser diameter in cops.
2. Improper selection of Spacer and missing of Spacer causes lean cops" randomly.
3. Un draft due to lesser top of pressure, missing of spacer and higher TPI in roving causes
lean cops
4. Improper centering of Bottom middle aprons, Improper centering of top arms leads frequent
end breaks causes "lean cops".
5. Slipped spindle leads frequent breaks that cause "lean cops".
6. Damaged bottom aprons, Improper centering of ring, ABC ring and lappet gauges leads
repeated breaks causes "lean cops".
7. Bobbin Exhaust should be filled in correct time unless that also causes "lean cops".
To avoid "Lean cops" preventive maintenance, on- line checklist will be very useful. If Ring data
installed in ring frame its a nice tool to short out the repeated breaks spindles that avoid lean
cops.
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Mr.K Pothiraj, GM-Business Development, Indorama Synthetics (I) Ltd, Coimbatore
A cop of a ring frame has three distinguishable parts viz., lower curved base, cylindrical middle
and a conical tip. A lean cop is one which does not meet the above characteristics of a cop and
has lower cop weight.
Lean cops are due to very fine count, excessive breakages on a particular spindle, very high
chase length and smaller ratchet wheel of ring frame builder motion. Eccentric spindles, bobbins
and none centering of spindles with rings and lappet contribute to higher breaks leading to lean
cops. Operators not attending to breakage in time and not creeling the bobbins in time after
bobbin exhaust also will lead to lean cops. Wrong selection of shaper wheel and or teeth per
stroke is also a reason for lean cops.
It is advisable to maintain cop diameter 2 to 3 mm less than the ring diameter to ensure smooth
running of Traveller. The chase length must be 15% more than the ring diameter for achieving
good cop shape. Winding length per cam revolution should be around 4 meters. Selection of
number of actuating pins in the heart cam and number of teeth in the ratchet should be done
depending on the count processed. Balancing of ring rail and lappet should be proper to avoid
lean cops.
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Mr.S. Ramakrishnan, Spinning Master, Sri Rajalinkam Tex, Vellakovil
Lean cops means Cop diameter is very low and shape is irregular i.e. called lean cops.
The following reasons for producing lean cops
1. Bobbin Hank variation is high.
2. Bobbin holder rotation is not free
3. Cracked or damaged cots are used
4. Spindles out of centre
5. Cracked or grooved Lappet Hook
6. Heavier Traveller usage
7. Top and Bottom Apron condition is poor i.e. grooved and holes
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Mr.P.Sivasamy, General Manager, Sadhana Spinners Limited, Kangeyam
Lean Cops: Because of frequent breaks, cops appear lean when compared to normal cops. Lean
cops weigh around 70% lower than normal cops.
Reasons for formation of Lean Cops
1. Running without or unsuitable spacer
2. Flies accumulation on Travellers
3. Nice roving
4. Damaged spindle or improper spindle gauge
5. Running without ABC rings
6. Damages in cots and aprons
7. Low pressure in Top arm.
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Mr.C.Sivakumar, Factory Manager, Sri Vasudeva Textiles Limited, Thekkupalayam,
Coimbatore
Lean Cops: Uneven cop diameter formation and low cop content
Reasons for Lean Cops in Spinning
1. Repeated Breaks: Mainly due to cots, apron damage, spindle out of centre. Narrow Traveller
clearer setting, lappet hook damage and improper centering
2. Fine Counts: Due to sliver peel off in simples (sliver splitting)
2. Wrong selection of Travellers: Too heavier and lighter Traveller Leeds frequent and multiple
breaks)
4. Traveller burn-out
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Mr.S.Murugeswaran, Production Manager, Shri Renuga Textiles Limited, Theni,
Tamilnadu
Lean cops are those which are not having standard cop content and creating more. Breaks in
winding department, various reasons are behind lean cops. They are classified as:
1. In efficient sider
2. More breaks in spinning due to poor centering, worn-out spindles, rings
3. Improper feed bobbin
4. Unmatch of Traveller in spinning
5. Improper RH inside the department
6. High apron groove or damaged apron running
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Mr.K.Thirumaran, Factory Manager, Alpine Knits India Pvt Ltd, Palladam, Coimbatore
Improper build and repeated breaks Spindles make lean cops in spinning. This is also called as
fancy or film fair award cops.
Reasons are:
a) Improper Combination of ratchet & Pawl as well as winding length.
b) Undrafted ends and variation in feed bobbins.
c) Improper selection of Travellers & it's Clearance as well as used Travellers.
d) In correct setting of ABC, Ring, Lappet bar & Hook etc.
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Mr.P.Kungumaraju, Factory Manager, Ramani Textile Mills Pvt Limited, Avinashi
Lean cops are the unshaped cops from spinning machine because of the mechanical problem in
the spindles.
The major reason for the lean cops is the more breakage in the spindle. The reasons may be as
1) Jerk in the ring rail. 2) Ring damage.3) Poor ring or spindle centering. 4) Replacement of
Traveller with unsized Traveller 6) Traveller clearer setting too close .7) Worn out aprons. 8)
Insufficient top roller pressure. 9). Poor quality of the roving input. 10) .Improper fit of the
spinning empties. .Because of the above said reasons the breakage rate will increase and lead to
frequency of attending the breakage will increase. Failure in the building mechanism will also be
the reason for Lean cops.
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Mr.M.Gopala Krishnan, Factory manager, MLR Mills, Karuvalur, Annur
Cops produced in 20% to 40% lesser than ring diameter from spinning called as lean cops. Lean
cops are formed due to Improper Traveller selection , Improper ratchet selection , Higher
breakage rate , Improper ring centering , Improper tape selection and brake condition .
This is the reason for producing lean cops.
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Mr. V.Vadivelu & Mr. U.Selvam, Technical team, Eniya Spinwell, Coimbatore
Lean cops are defined as "the cops which is obstructed by normal spinning leads to repeated
breaks and seems to be lean". Insufficient top arm pressure, Improper spindle and lappet
alignment, Bobbin holder struck up, damages in cots, aprons, roving guides, flutted rollers,
lappet hook and separators will led to lean cops.
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Mr.K.Kannan, Spinning Master, Sri Dhanalakshmi Sizing & Spinning Mill Limited,
Karumathampatti
A cop is having low content of yarn and improper shape than the regular cops are called lean
cops. Also, having low CSP and Quality defects. The main reason for formation of lean cops is
repeated and unnecessary yarn breaks in a particular spindle. Higher yarn breaks due to
improper selection of Traveller number and profile. Poor condition of rings and ring centering is
not good. Spindle wobbling is high due to damaged bolsters. High H1 faults due to singles in
roving stage and high stretch of roving in simplex and spinning stages. Also, damaged cots and
aprons.
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Mr.R.Varadaraju, Manager-QC, Sri Ramakrishna Mills Limited, Coimbatore
Lean cops are defined as cops with much lesser cop content and cop diameter than regular cops
by lesser than 25%. Lean cops are produced due to very high end breakage rate in those
spindles due to one or more of the following reasons.
Spindles out of centre worn out rings frequent wear out of traveller, traveller ply-off due to
worn out ring/traveller (or) miss match of ring and travellers, worn out/cracked aprons/cots,
cots, unsteady rotation of top rolls, uneven or very fine or low twist or high twist Simplex
bobbins etc.
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Mr.B.Rajkumar, ASM, Mahendra Spinning Mills (P) Limited, Navakarai, Coimbatore
Reduced diameter of normal cops (Below 75%) caused by repeat breaks by particular spindle
and the cops have lesser yarn content with huge piecing called Lean Cops. Faulty Spindle,
Spindle out of Centre, Lappet away from centre, cots damage, Top or Bottom roller
eccentricity, irregular movement of apron, over traverse of roving, Spacer missing, non - free
rotating of bobbin holder, faulty bobbin from simplex are some reason for formation of Lean
Cops.
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Mr.S.Sivaperumal, Factory Manager, Sree Koppammal Spinning Mills, Aruppukottai
Lean Cops are the cops having considerably lesser diameter through out its lift. (Standard
diameter may be 1MM lesser that Ring diameter. The reasons may be the following:
1. Wrong selection of retched wheel, i.e., with lesser teeth
2. Moving of more number of teeth in ratchet by pawl for each ring rail movement
3. Long run finer hank roving bobbins in the ring frame, which are produced by mistake in
simplex
4. Roving guide chock with fluff, apron chock with fluff and faulty bobbin holders
5. More or frequent breaks in some spindles due to some reasons
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Mr.S.Sripathi, Factory Manager, Vajram Spinning Mills (P) Limited, Rajapalayam
Under diameter of cops than the normal build up of cops to the ring diameter
throughout it formation is called lean cops.
Abnormal variation in micronire value from mixing to mixing. Spinning of finer count than the
normal count. Wrong selection of ratchet wheel. Wrong setting of ratchet movement. Singles
emerging from Draw frame and to the roving stand, worn-out rings and unsuitable Traveller,
spindle out of centre, close setting of Traveller cleaner and other causes leading to frequent
breaks.
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Mr.K.Senthilkumar, Factory Manager, Raju Spinning Mills Ltd, B-Unit, Srivilliputhur
Lean cops are seeing entirely different in diameter and shape from regular spinning cops. Lean
cops are caused by variations in spindle and lappet gauges and improper alignment in cradle
setting and in spindles with repeated breakages. Lean cops may come by using worn out
Travellers by the workers bad practices of taking the Travellers underneath the spinning m/c.
Further hank variation in roving may produce lean cops.
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Mr.S. Sannkarabagam, Mill Manager, Pariyur Amman Spinning Mills, Gobichettipalayam
Lean cop is nothing but finer count yarn than normal running count or other version smaller
diameter Cops than normal size of the cops. This is mainly produced due to singles in roving
Bobbins. Due to spindle out of centre this type of Cops will be produced. Due to worn out
Traveller this will be produced. Due to wrong ratchet wheel selection these types of cops will be
produced.
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Mr.Mahendra V. Bhoyar, GM-Technical, Bhandari Exports Ind. Ltd, Lalru, Punjab
Lean Cops: Ideally Ring Frame cop diameter should be less by 4-5 % than Ring diameter, if cop
diameter is lesser than this as compared to Ring diameter is called lean cops.
Reasons are finer roving than normal roving hanks used for particular counts. Apart from this,
excessive breakages at particular spindle are main cause of formation of lean cops. The reason
for excessive breakages of yarn may be due to worn out rings, Travellers, improper rings gauge
eccentric spindles, worn out ABC ring, lappet hooks, damaged cots/Aprons, missing spacers
excessive, stretch to rove on R/F creels, Improper top roller pressure etc.
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Mr.K.S.Sankar, AGM(Maint), GTN Industries Ltd, Nagpur
Lean cops are produced from the ring spinning machines; ring frame cop diameter which is not
matching with adjacent spindle (or) the entire ring frame is called as Lean cops. Normally in my
experience, cop diameter which is less by 10% and above can only be visible as a lean cop, when
we check the quality parameters it will not match with normal cop such as, lower CSP & RKM,
more hairiness, high IMP and higher count CV%, etc
Major reason for formation of lean cop is due to , ring Traveller is heavier by 3 to 4 numbers
than the adjacent spindle ,wear out ring Traveller, closer r/t clearer setting than recommended
ring flange damages & wear out, more end breaks , groove and cut formation in the lappet eye
and roving hank fed is finer than requirement, etc.
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Mr.T. Ravi, Dy.Manager, Super Spinning Mills Limited, C-Unit, Karur
Lean cops are due to in correct ratchet wheel teeth and improper activation of ratchet pawl. In
accuracy in achieving the perpendicular angle of pocker with respect to spindle beam. Bottle
shaped cops are due to defective apron movements and damaged aprons. Steps formation on the
cops is due to resistance of ring rail at one point either due to defective builder cam or due to
elongated chains are having correlation with lean cop’s formation in spinning.
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Mr.S.Senthilkumar, Manufacturing Manager, Thambbi Modern Spinning Mills Ltd,
Salem
Lean Cops: Cops which are produced with under diameter or built with very high tension or with
repeated breaks are known as LEAN cops.
Reasons:
1. High yarn tension due to improper centering of Spindle, Ring, ABC rings & Lappet guide
2. High yarn tension due to the selection of HEAVIER travellers
3. Repeated breaks in particular spindle due to various reasons
4. Production of wide difference finer count than normal yarn due to wrong bobbin feed.
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