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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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