Showing posts with label Spinning. Show all posts
Showing posts with label Spinning. Show all posts

Sunday, October 17, 2010

VORTEX SPINNING SYSTEM


Not all succeeded with the technology of Airjet spinning. But one , who acheived much better success in Airjet spinning system and it seems they successfully convinced many spinners as well as knitters that this yarn can really make some difference.

With the technological machines started from Roller Jet Spinning to Vortex Spinning , the company " Muratec " made an difference with their latest "VORTEX SPINNING MACHINES".

While Ring Spinning remains most successful spinning system yet today , we can not deny unique advantages which 'Vortex' yarns give.



In Ring Spinning improving Hairiness & Production reached almost saturation level , in which 'Vortex' gives excellent results.


Advantages ;

Less hariness & Clear appearance
High resistance to Pilling & abrasion
High moisture absorption
Less shrinkage & High wash resistance
Can be spun with various other materials such as cotton, synthetic fiber, regenerated fiber and blended fiber.
Yarn structure also suitable as core yarn.


MORE TECHNOLOGICAL ADVANTAGES ARE EXPLAINED HERE IN DETAIL.

The above is stated in Muratec website. We cant say everything good about 'vortex' there are some serious issues to be discussed. in which we still need to concentrate.

- THE STRENGTH AND TENACITY
- BY MEANS OF UNIQUE TWISTING PROCESS , YOU GET LESSER HAIRINESS AND VERY UNIFORM YARN STRUCTURE , ALONG WITH YOU GET VERY LESS STRENGTH AND ELONGATION. WHICH RAISES A QUESTION , HOW SUCCESSFUL THIS TECHNOLOGY IN CASE OF WEAVING. WITHOUT SUFFICIENT STRENGTH YOU CANT USE ANY YARN IN WEAVING , WHEREAS IN KNITTING IT CAN BE STILL WORKABLE AND MANAGEABLE.

ACCEPTABLITY FOR ALL MATERIALS.

- AS OF MY UNDERSTANDING , THE VORTEX SYSTEM IS SOME WHAT SUCCESSFUL IN 100% RAYON ( VISCOSE ) COUNTS ESPECIALLY WHEN USED IN KNITTING FASHION FABRICS.

- HAVE BEEN INFORMED BY SOURCES IT CAN BE SUCCESSFULLY USED FOR TR BLENDS TOO.

APART FROM THE ABOVE STILL OTHER MATERIAL YARNS ARE NOT ACCEPTED BY THE END USERS.

EXCESSIVE FIBRE LOSS DURING SPINNING ALSO RAISES A CONCERN ESPECIALLY WHEN SPUN WITH NATURAL FIBRES WHICH HAS IRREGULAR LENGTH OF FIBRES.

BY CONSIDERING THE INITIAL INVESTMENT , HIGH PRODUCTION AND SO ON , VORTEX WILL BE A SERIOUS THREAT TO OPEN END SPINNING SYSTEM


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

http://www.expresstextile.com/20050630/technext01.shtml


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.
-----------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------
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.
---------------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------
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.
---------------------------------------------------------------------------------------------------------------
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.
---------------------------------------------------------------------------------------------------------------
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.
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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.
---------------------------------------------------------------------------------------------------------------
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.
-------------------------------------------------------------------------------------------------------------------------------

Article 1 : Reasons for Lean Cops in Spinning

Mr.M.R. Surendran, Factory Manager, Nallam Maniam Textiles (P) Ltd., Vellakovil

“Cops which are produced by the spinners mending yarn with repeated ends down consistently
Ignoring the root cause of the breaks – “ are Lean Cops. Lean Cops may be classified into two
categories
1 .Lean cops due to lapses in process control
2. Lean cops due to lapses in maintenance process
When we consider lapses in process control the following relatively attributes to lean
cops .Too much count variation. Count abnormally on finer side. These are against the lapses
in process as briefed here below:
1. Singles in drawing silver due to creel stop motion failure and due to workers not adopting
end to End piecing.
2. Pneumatic suction excess in drawing and simplex. Clearer hoods are not set in position.
3. Split up silver both in draw frame and simplex creel stage and in drafting zone. Split up
roving in Simplex frame
4. Abnormal stretches in drawing and simplex creel stage and in drafting and simplex creel as
well as roving stretches.
5. Improper layering of silver in draw frame cans and projected rivets which causes sliver tear
out casing singles in case of mills where end less cans are not in use.
In the case of lapses in maintenance process the following are to be looked into:
1. Abnormal sliver and roving irregularities due to mechanical disturbances at drawing simplex
and spinning gear units and individual bearing points.
2. Jerky motion of bobbin holder and subsequent creel stretches.
3. Creel guide rods with peeled off coated portion.
4. Roving guide clogged with waste.
5. Jammed top rollers.
6. Channeled bottom and top aprons, which causes fibre plucking and breaks.
7. Spacer opening either too open or too close.
8. Very low top roller pressure.
9. Damaged flutes on bottom fluted rollers, Knife cut and pits on top rollers.
10. Lappet out of centre
11. Groove formation on lappet hook
12. Peeled off coated portion in ABC ring, Damaged separator if ABC rings are not provided.
13. Usage of worn out rings Travellers
14. Worn out rings and eccentric rings
15. Spindle Vibration and spindle out of centre.
16. Loose Tapes and Improper Jokey Pulley tensioning.
Like wise we can list out reasons for Lean cops. Accordingly we should take Remedial action
timely diagnosing reasons sensibly. If not lean cops arrested to zero, market complaint from
sources like warping – knitting –Sizing and other processing centers are given warm welcome.
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Tuesday, June 2, 2009

Spinning : Technology & The Future - M M Ahmed

After advent of compact spinning, yarn quality parameter has changed, especially in respect of hairiness, strength and in some respect Imperfection.

Here is a research work in respect of modified spacer and cradle in further improvement of yarn quality of compact yarn & conventional yarn. Today, the main goal of companies is to achieve improved yarn quality that will ensure better competitiveness and higher yarn prices. Current spinning technology developing is aimed at how to maintain higher productivity with effective quality control, by selecting suitable equipments and spinning conditions to match with the raw materials. So, modern developments of machinery, labor demand and increasing market competition compel the spinner’s to produce as satisfactory yarn as is economically possible. Abstract: The article presents the comparison of modified spacer and cradle VS normal. I have analyzed and compared the physical mechanical etc. parameters from the same cotton, cotton/polestar (CVC) roving and same spindles were performed, in different modern group mills with state of the art machines / normal machines are described within this work. The purpose of this study to determinethe influence of modified and normal spacers and cradles on yarn quality in compact and normal spinning and to compare the produced yarn, specially Imperfection (long/short).

Key Words
Conventional spinning, compact spinning, normal spacers, modified spacer, normal cradle, modified cradle yarns, imperfection (IPI),uniformity (U %).

Introduction and Motivations
In spite modernization and rapid technological development in the field of ring spinning, the mechanism ring-traveller spindle has remained almost the same until now. Furthermore, ring spinning remains the dominant spinning technology even today. The producers of modern spinning frames have been developing the machines with improved construction of different working elements and optimal spinning geometry, with a ring diameter of 36 mm, a tube length of 180 mm and spindle speed of up to 25,000/min.

Besides the conventional functions (spindle speed, delivery speed, productivity, twist, draft, machine efficiency), computer-based system control and enable the optimization of spinning conditions (formation of bobbins, position of ring rail, automated doffing and setting of empty tubes, cleaning and oiling of main machine parts). Construction improvements of different working elements of the ring-spinning frame and optimized spinning geometry of the continuous from of fibres (roving or sliver) enable increased productivity, better yarn quality, as well as flexibility and profitability of the process.

The irregularity introduced in drafting mainly depends upon the parameters of the drafting system, mechanical faults and quality of the input material. When mechanical faults are eliminated, drafting ir-regularities depend upon to control on the floating fibers in the drafting zone. Setting between the roller nips, distance between the apron at the nip, distance between the apron at the nip, and pressure on the top roller are some of the factors. The characteristics of the sliver fed to the drafting system also exercise considerable influence on the irregularities introduced and drafting system operated under the optimum conditions. Short fiber content, neps, trash and other impurities degree of fiber parallelization and number and extend of residual hooks in the fibers together with their direction of presentation are some of the important factors that characterize sliver quality and determine its behavior during drafting.

Nutter and slater examined the effect of hooked fiber on yarn strength and found that better strength is obtained when a fiber tip is presented to the drafting system than a hooked end. Grade, Wakanker and Bhaduri found better yarn regularity and strength when majority hooks are fed as leading. Simpson, Deluca and Flori also confirmed that feeding majority hooks as leading to the ring frame contributed to poorer yarn quality and more breakages, the effect being pronounced in case of fine yarns. Apart from hooks, the fiber parallelization may also effect on drafting irregularities.

The treatment given to raw material during spinning process throughvarious machines greatly influences not only the quality of spun yarn but also its quantum. Factory like setting betwe e n r o l l e r s, d r a f t distribution, Pressure on top
rollers, shore hardness of rubber cots, spacers, type/size of ring travelers, rings, relative humidity in the plant and mixing of raw material etc, contribute towards the quality and quantity of yarn. Moisture content in the raw material especially in cotton is very important because of its direct effect on yarn strength as well as elongation and neps in the yarn. Whereas the strength and elongation directly affect the performance of yarn in warping, the neps influence surface of finished cloth and dye take up.

Fiber breakage is a very important factor, because any increase in breakage can lead to additional fly waste and greater number of ends down. Fiber breakage is a function of two main factors; the ratch setting and the roving twist. To avoid breakages, it is necessary to set the ratch longer then the longest fiber, because a shorter ratch will break all fibers greater in length. For a given ratch the extent of machine control over the fiber depend on the length distribution; a wider distribution and a longer ratch lead to lesser fiber control. The strain and distortion imposed on fiber ends during drafting due to the initial pull, continually repeated at each operation also lead to an increase in breakages. It is to be expected, therefore, that fiber will be beheaded or be tailed as a result of this stress and fatigue, the effect being more pronounced in case of longer fibers.

Material and Methods Material
These studies were carried out in modern mills with state of art machines and normal spinning mills using the same mixing, whichmills were using for there regular production, on conventional and compact systems were using. Same mixing with same preparatory process and spinning parameters with same roving and on same spindles. In each mills spinning was done minimum one week and in 2 group mills spinning is performed more than two months and yarn is tested daily on the same doff position. Results are the average of all test results done in respective mill.

Yarn Testing
All testing are done in there own mills labotry, where experiments are performed.

Quality properties of produced yarn
Quality results observed in this study in respect of IPI (short/long) 40 to 60%, uniformity 6 to 10% improvement is noted, where as others quality parameters are also satisfactory.

Results & Discussion
1-Nip distance between front top roller to top and bottom apron nip nearly 12mm and this is the distance in which fiber less than 12mm float freely here and there and with out control, which causes high imperfection (IPI) to control less than 12mm fibre in front zone Modified Spacer are used instead of normal spacer, which helps to reduce long/short IPI in different counts 40 to 60% and uniformity about 6 to 10%, where as remaining results are same or better than normal spacer. Which was the aim of this research. Experiments are done in different locations (Punjab & Sindh) with medium and long cotton, even on CVC also and same trend is noted.

2-In ring spinning there are two drafting zone, one is front zone and second is back zone. In back zone Modified Cradle are used. The reason to use modified cradle was to aligned fiber more parallel and with less hook before entering between top and bottom apron, which also help to improve quality parameters like long/short IPI, uniformity etc.

3- Combination of modified spacer and cradle both. Improvement is also noted. For detail please see count Tex 9.84 (Ne 60)

Work in progress
For more detail work on above subject are still in progress on different count on different locations on different medium and long cotton, carded, semi-combed, combed and cotton blended yarn. Studies on Autocone cuts, classimat etc; are also in progress. Also studies are in progress in down stream processes.

Conclusions
On the basis of this study there is more room for improvement with different combination.

About the Author

  • Presently involve in R&D (Research and development).
  • Qualification: M.sc, C.Txet.ATI (Textile Institute Manchester, U.K), ICS Diploma in, “Carding & Spinning” from Pennsylvania (USA), ITC from, “City & Guild” London (UK).
  • Training/Courses from, Germany, Italy, Japan, Switzerland & China.
  • Management Training Course from, “The Association of Overseas Scholarship” (AOTS) Japan. Leadership Improvement & Communication in an Organization” (AOTS) Japan. “Kaizen Management, Cost & Profitability Analysis” (AOTS) Japan. “Auditor / Lead -Auditor” IQA-IRCA (U.K), “Introduction to ISO 9000:2000”.“Internal Quality Auditing for ISO 9000”.
  • “Energy Conservation in Industry” (ENERCON), Training / Courses etc.
  • Specialization in Compact Spinning.
  • Mills experience 20 years in reputable groups and mills (Manager to Technical Director)
  • Research experience 2 years as, “Senior Research Officer” (SRO) in,“Pakistan Institute of Cotton Research & Technology Karachi” (PICRT) Pakistan Central Cotton Committee (PCCC) “Ministry of Food & Agriculture, Government of Pakistan”
  • Teaching experience 1 year in, “Institute of Leadership & Management” (ILM) Lahore
  • Consultancy experience 12 years in, Group & Reputable Mills

Productivity Of A Spinning Mill By Gaurav Doshi

All spinners wish that the spinning productivity of their mill (ring frame production in gms/spindle shift) has the optimum level of efficiency. Though there are many aspects that limit the actual production ­like ring diameter and its age, lift, age and make of the ring frame, its maximum mechanical speed, type of spindle drive, lot size, fluctuating production program, poor control on RH, lower HP of main driving motor, greater percentage of untrained workers, impoverished technical knowledge of subordinates etc.

Today, there is a pressure from the management to decrease the conversion cost to its lowest possible level because of cut throat competition in both the local and export markets. Ring spinning contributes approximately 70 per cent to the total conversion cost. Hence it is possible to speed up the ring frames to its maximum speed mechanically possible ­considering that spinning preparatory can feed ring frames at high speed. Also, neither the spinning performance nor the yarn quality is adversely affected by such speeding up of the ring frames.

Currently many spinning mills in India are capable of managing their ring frames at actual great speeds quite successfully counts 30s-40s at 20/21/22,000 rpm and finer counts - 60s-76s at up to 24,500 rpm and yet maintaining identical breakage rate of 2-3 breaks/l00 spindle hrs that they were earlier performing at 15/16,000 rpm. Also, the yarn quality has not been affected.

Factors that affect spinning productivity

Many factors that affect spinning productivity/end breakages/ yarn properties/ yarn complaints are mentioned here. Increasing productivity is not just gearing up the ring frames but making many efforts such as arranging proper fibres bales to blowroom in a particular direction, maintaining product quality at spg preparatory machines, care of cots and aprons, QC checks, etc., to make sure that spinning breakages, winding breaks, vital yarn properties and quality of yarn at the looms should not deteriorate at all.

Polyester staple fibre associated factors

Change the fibre denier, if possible, to the next stage i.e. if a mill is using 1.4 Den fibre, they can use 1.2 Den. Several advantages here are 20­25 per cent higher number of fibres in the cross section giving to superior yarn strength, improvement in uster value, lesser imperfections and reduced hairiness - which in turn improves weaving performance up to 4-6 per cent with Sulzer weaving machines.

The 'compromise' cut length is 44 mm, though it is believed that in the next 5 years or so, mills will change to 38 mm as is the practice world wide.

Many fibre manufacturers give actual values of important fibre properties with each dispatch. How much the mill technicians consider these values provided by the fibre manufacturers is a debatable issue. It has been seen that most of the mill technicians do not have the proper knowledge to evaluate these values of fibre properties. Of course, it is a good idea if the fibre manufacturers provide the information.

In fact the actual values of the following fibre properties should be given with every dispatch:

. Actual denier

. CV% of denier

. Actual tenacity gms/denier

. Actual per cent elongation at break

. T10gms/denier

. Crimps / 25 mm

. Crimp stability

. Crimp take-up

. Actual oil pick-up and its variation. Actual Dry Heat Shrinkage (@ 180°C for 30 minutes)

. Fused fibres (in mg/10 kg of raw fibre)

. Over lengths/multi lengths - Number per 10 gms

. Actual b colour

Polyester fibre bales to blowroom

Most fibre manufacturers should make sure that dispatch of bales is done in serial order. The reason is that the bales are placed in the warehouse in that order. Today's fibre plants are highly productive. Limits sets in which it make about 120 tons/day, are common. Hence a truck load of bales get made in just 2 hrs or so.

The fibre properties do not vary within 2 hrs, but if it takes more days or say a week, many fibre properties do change some times even outside the set limits. So it helps day' variations are taken care of very well. This ensures smoother running of fibres and no problems of rings under UV and dye variation in the final fabric

It is noted that holding a stock of more than 4 or 6 trucks constantly involves blocking of capital, but

. Ensured no complain of dye variation - streaks warp way and bars weft way

. Ensured no problem of rings under UV lamps.

Hence the benefit received outweighs the extra financial burden. Many mills that have been pursuing this and have gained fully the 3 plus points privilege of above. In Indonesia, many mills utilize Blendomats where 36 bales are placed at one time, hence blending of fibres made on different days.

Performance at spinning preparatory machines

Check that all mechanical data ­total/break drafts, roller settings, TM (Twist Multiplier) etc, even trumpet diameter is completely matching on each and every machine working on one mixing. Changes in C.P (Change Pinion for change in draft) to be done on 'group' basis according to the material being used so as to have minimum machine variations.

Though blending for bales produced is important, it is likewise important to:

1. Number the card cans

2. Check that all cards working on a mixing are represented in the creel of the breaker draw frame

3. Use cans of two different colours at the two deliveries of breaker draw frame

4. Place 4 cans of each colour in the creel of the Finisher Draw frame.

In this way one will have intimate fibre to fibre blending.

Verify all stop motions at both breaker and finisher draw frame and check whether these are functioning well. Also check that the auto leveler is functioning properly.

Check winding tension on the roving remains identical throughout the build of the roving bobbin. Check this by getting 4 full roving bobbins - 2 from front row and 2 from back row; get at least 5 wrappings and work out the average. Place empty roving bobbins on the same 4 spindles and operate the machine until approximately 200 metres is wound up; then detach bobbins and verify wrappings. The variation between the average of wrappings of 'full' and 'empty' bobbins should be less than 2 percent.

Check that no roving bobbin with Uster U percent of greater than 3.5 is sent to ring frames. In order to verify this, check Uster U percent of each and every roving bobbin from a frame once every month. Spot out if there are any arms that are producing off spec bobbins. Get the top arms attended to and recheck the Uster U percent.

Check that the drafting device at the fly frame is only adding 'allowable' unevenness. By having Uster U per cent of finisher sliver, apply the following formula to envisage roving U per cent (U per cent of roving x 1.25)2 = (U per cent of Finisher drawing x 1.25)2 + K, K may be considered as 10.

If the actual roving U per cent is considerably greater than the expected U per cent value, then go for the drafting system, checking conditions of roll­ers, cots, aprons, roller pressure, setting, draft distribution etc. One feasible cause could also be that the total draft is too high. Also check by inspecting Spectrograms of rovings with greater U per cent that there is no interrupted work.

It is important to verify the condition of each and every cot and apron in the mill very frequently, which is practiced daily in Indonesia and once a week by a senior person in India; and any faulty cot/apron is right away put back.

It is noted that if the finisher drawing sliver's U per cent is 1.6; CV per cent of wrapping is 0.22 and the spectrogram proves no interrupted irregularity, then this sliver will function at fly frame with practically zero break; and this roving will function on ring frames with 2/3 breaks/100 spindle hrs at ring frame working at real high speed ­considering ring spinning is well managed but in real life - mainly in textile industry sometimes something else will happen and mill could end up with 10 breaks/100 spindle hrs at high speed.

Ring Frame control

Considering that a spinning mill has accepted all the steps mentioned above, even then the following points need to be focused upon:

Make sure that mechanical data is matching on all ring frames working on one mixing, changes in change pinion be done on 'group' basis. If the actual roving U per cent is considerably greater higher, then, go for the drafting system, conditions of rollers, cots, aprons, roller pressure, setting, draft distribution etc.

Cots and aprons should be tested daily - or at least once in 2/3 days. Also ring travellers should be altered on schedule.

To get a pulse on the functioning at ring frames, best is for the spinning manager himself to carry out snap round compromising all ring frames for number of spindles per frame not making yarn at various intervals of the day. This snap round does not bear much time. A worksheet to be maintained in the department with the following data:

. Date

. Time at start of Round

. Time at end of Round

. Dry Bulb degree Celsius

. Wet Bulb degree Celsius

. RH per cent

. Idle spindle report due to the below mentioned reasons:

1. Spindle break

2. Lapping: top roller, bottom roller

3. Roving: break
exhausted

4. Mechanical

5. Other

It is noted that taking snap rounds is up to 2 spindles not making yarn per frame is pragmatic in good Indian mills and as low as less than 1 spindle not making yarn per frame in good Indonesian mills. In general, if a mill has 2 spindle or less not making yarn/frame (irrespective of the no. of spindles/ frame) then the mill is performing well.

At last consider control on Relative Humidity. A lot of spinning mills still apply wet and dry bulb thermometers. (Many a times water is not placed in wet bulb). The perfection here is exclusively dependent on the perfect judgment of the person who notes down the temperatures. However meters with digital display of both temp and RH are offered, it is recommended putting thermo hygrographs note down temperature and RH continuously for say 24 hrs. Every morning the spinning personnel should check the shape of the trace mainly of RH and in this regards they have to maintain some kind of standardized RH in the department.

There was doubt that with high speed spinning, traveller temperature will increase to blend polyester fibres in the yarn. Luckily nothing like this has happened and blend spinners can carefully run their ring frames even at 25,000 rpm.

Conclusion

It is observed that if a spinning mill follows the steps recommend as above, they can function their ring frames at speeds up to 25,000 rpm (It appears that 25,000 rpm is still the higher limit even at ITMAA Singapore October 2005) without either rising the breakage rate weakening yarn quality. The recommendation provided here is based on experts' experience of functioning with many spinning mills in India and Indonesia increases spinning productivity.