Faults in spun yarns..........

2. Prepared By : Muhammad Sohail
ID: 12-NTU-0024
12th Batch
Yarn Manufacturing Technology
Email: msohail410@ymail.com
National Textile University
National Textile University
Department Of Textile Engineering
Mananwala, Faisalabad, Pakistan
Prepared By :

4. Yarn content in the cop is less
1

5. EFFECT
Efficiency loss in ring frame
•Drop in winding efficiency
•More knots for a given length of wound yarn
CAUSES
Under utilisation of bobbin height
Lower number of coils /inch
Higher chase length
Cop bottom bracket properly not set
Improper selection of ratchet
Ratchet pawl pushing number of teeths/movment in the ratchet wheel
Spinning empties wall thickness is high
RECTIFICATION
Optimum chase length, coil spacing and wall thickness of empy cops tobe ensured
1. Ratchet/pawl movement to be properly set
2. Free space of only 7.5mm to be maintained at the top and bottom of
the cop
3. Free space only 0.75mm only to be maintained between full cops and
the ring

6. An abnormally thick place or lump in yarn showing less twist at that
place.
2

7. EFFECT
More end breaks in the next process.
 Damaged fabric appearance.
 Shade variation in dyed fabrics.
CAUSES
Accumulation of fly and fluff on the machine parts.
Poor carding.
Defective ring frame drafting and bad piecing
Improperly clothed top roller clearers.
RECTIFICATION
1. Machine surfaces to be maintained clean.
2. Proper functioning of pnemafil/roller clearers to be ensured.
3. Broken teeth gear wheel to be avoided and proper meshing to be
ensured.
4. Better fiber individualisation at cards to be achieved.
5. Optimum top roller pressure &back zone
6. Setting at ring frame to be maintained.

8. Yarn containing rolled fibre mass, which can be clearly seen on
black board at close distance; measurable on Uster
imperfection Indicator.
3

9. EFFECT
Damaged fabric appearance
•Shade variation in the dyed fabrics
•An abnormally thick place or lump in yarn showing less twist at that place
is called slubs
CAUSES
Accumalation of fly and fluff on the machine parts
Poor carding.
Defective ring frame drafting and bad piecing
Improperly clothed top roller clearers.
RECTIFICATION
Machine surfaces to be maintained clean.
1. Proper functioning of pnemafil/roller clearers to be ensured.
2. Broken teeth gear wheel to be avoided and proper meshing to be
ensured.
3. Better fiber individualisation at cards to be achieved.

10. Yarn with kinks(twisted onto itself)due to insufficient tension after
twisting
4

11. EFFECT
Entanglement with adjacent ends causing a break
•Damaged fabric appearance
•Shade variation in dyed fabrics
•Improper meshing of gear wheels
•Mixing of cottons varying widely in fiber lengths and use of immature
cottons
CAUSES Higher than normal twist in the yarn
Presence of too many long thin places in the yarn
RECTIFICATION
Optimum twist to be used for the type of cotton processed
1. Drafting parameters to minimise thin places in the yarn to be adopted
2. The yarn to be conditioned
3. Correct tension weights and slub catcher settings to be employed at
winding

12. Measurable by Uster Imperfection Indicator and observable on
appearance
5

13. EFFECT
Eccentric top and bottom rollers
•Insufficient pressure on top rollers
•Worn and old aprons and improper apron spacing
•Improper meshing of gear wheels
•Mixing of cottons varying widely in fiber lengths and use of immature cottons
CAUSES Eccentric top and bottom rollers
Insufficient pressure on top rollers
Worn and old aprons and improper apron spacing
Improper meshing of gear wheels
Mixing of cottons varying widely in fibre lengths and use of immature
cottons
RECTIFICATION
Eccentric top and bottom rollers to be avoided
1. Top arm pressure checking schedules to be Maintained strictly
2. Wide variation in the properties of cottons used in the mixing to be
avoided
3. Better fiber individualisation at cards to be achieved.
4. Correct spacers to be utilised

14. Yarn which is weak indicating lesser twist
6

15. EFFECT:
More end breaks in subsequent processes
•Shade variation in dyed fabrics
CAUSES:
Slack tapes dirty jockey pulleys
Improper bobbin feed on the spls
Less twist in the yarn
Bad clearing at the travellar
RECTIFICATION:
Vibration of bobbins on the spindles to be avoided
1. Proper yarn clearing to be ensured
2. Periodic replacement of worn rings and travellars to be effected

16. Yarn stained with oil
7

17. EFFECT
Damaged fabric appearance
•Occurrence of black spot in fabric
CAUSES
Careless oil in the moving parts,over head pulleys etc
Piecings made with oily or dirty fingers
Careless material handlings
RECTIFICATION
Appropriate material handling procedures to be followed
1. Oilers to trained in proper method of lubrication
2. Clean containers to be utilised for material transportation

18. Very small snarl-like places in the yarn which disappear when pulled with
enough tension or Yarn with spring –like shape
8

19. EFFECT
More breaks in winding
•More noticable in polyester and cotton blended yarns
CAUSES Mixing of cottons of widely differing staple length
Closer roller settings
Eccentric top and bottom rollers
Non optimum temperature and relative humidity in the spinning
shed
Over spinning of cottons
RECTIFICATION
Optimum top roller pressure to be maintained
1. Mixing of cottons varying widely in fibre length to be avoided
2. Use of optimum roller settings
3. Use of properly buffed rollers free from eccentricity to be
ensured

20. Unduly thick piecing in yarn caused by over End piecing
9

21. EFFECT
More end breaks in subsequent process
•Increase in hard waste
CAUSES Wrong method of piecing and over end piecing
Twisting the ends instead of knotting
RECTIFICATION
Tenters to be trained in proper methods of piecing
1. Separators to be provided
2. Excessive end breaks in spinning to be avoided

22. Slub in the yarn stained with oil
10

23. EFFECT
More end breaks in the ensuring process
•Damaged fabric appearance
•Shade variation in dyed fabrics
CAUSES Accumulation of oily fluff on machinery parts
Poor methods of lubrication in preparatory processes
Negligence in segregating the oily waste from process waste
RECTIFICATION
Yarn contact surfaces to be kept clean
1. Oilers to be trained in correct procedures of lubrication
2. Proper segregation of oily waste from process waste

24. Presence of black specks of broken seeds, leaf bits and trash in yarn
11

25. EFFECT
Damaged fabric appearance
•Production of specks during dyeing
•Needle breaks during knitting
•Poor performance during winding
CAUSES Ineffective cleaning in Blow room and cards
Use of cottons with high trash and too many seed coat fragments
RECTIFICATION
Cleaning efficiency of blow room and cards to be improved
1. Optimum humidity in the departments to be ensured

26. Protrusion of fibre ends from the main yarn structure
12

27. EFFECT
More end breaks in winding
•Uneven fabric surface
•Beads formation in the fabric in the case of polyester/cotton blends
CAUSES Use of cottons differing widely in the properties in the same mixing
Use of worn rings and lighter travellars
Maintaining low relative humidity, closer roller settings and very high
spindle speeds
RECTIFICATION
Use of travellars of correct size and shape and rings in good condition to be
ensured
1. Periodic replacement of travellars and suitable
2. Roller settings to be maintained
3. Optimum relative humidity to be maintained in the spinning room
4. Wide variation in the properties of cottons used in the mixing to be
avoided

28. Metallic parts, jute flannel and other similar foreign matters spun along
with yarn
13

29. EFFECT
Breaks during winding
•Formation of holes and stains in cloth
•Damaged fabric appearance
CAUSES Improper handling of travellers
Improper preparation of mixings
RECTIFICATION
Removal of foreign matters(such as jute fibres,colour cloth bits) to be
ensured during preparation of mixing
1. Installation of permanent magnets at proper
2. Places in blow room lines to be ensured

30. Fly or fluff either spun along with the yarn or loosely embedded on the yarn
14

31. EFFECT
More breaks in winding
CAUSES Accumulation of fluff over machine parts
Fanning by workers
Failure of over head cleaners
Malfunctioning of humidification plant
RECTIFICATION
Machinery surfaces to be kept clean by using roller pickers
1. Fanning by workers to be avoided
2. Performance of over head cleaners and humidification plants to
be closely monitored

32. It is a double yarn which one yarn is straight and other is coiled over it
15

33. EFFECT
Breaks during winding
•Causes streaks in the fabric
CAUSES Feeding of two ends (instead of one ) in ring frame
Lashing -in ends in ring frame
RECTIFICATION
Tenters are to be trained in piecing methods(or) practices
1. Pneumafil ducts to be kept clean and properly set

34. Coils of yarn coming out of the ring cops in bunches at the time of unwinding
16

35. EFFECT
Increase in end breaks
•Higher yarn waste
CAUSES Improper ring rail movement
Worn builder cam
Loose package and excessive coils in the package
Soft build of cops
Improper empties fit on the spindles and slack tapes
RECTIFICATION
Ring rail movement to be set right
•Optimum ratio of winding: bindings coils and optimum chase
length to be maintained

36. Damaged layers on the surface of the ring cops
17

37. EFFECT
Excessive breaks during winding
• More hard waste at winding
CAUSES Spindle or empty cops wobbling
 Use of lighter travellers snd incorrect ratchet wheel
 Movement of spindles to the rings not concentric
RECTIFICATION
Worn spindles to be replaced
1. Improper fit of empty cops with spindles to be avoided
2. Gauging of spindles with rings to be properly carried out
3. Use of right type travellar and ratchet wheel to be ensured

38. Step-like appearance of the cop
18

39. EFFECT
Slough-off during doffing/winding
• More breaks during unwinding(due to slough off)
• Higher hard waste in winding
CAUSES Improper combination of ratchet and pawl
 Jerky ring rail movement(pocker rod movement to check)
RECTIFICATION
Ratchet and Ratchet/pawl movement to be accurately arrived at taking into
consideration
1. Count of yarn, ring dia and chase length
2. Lubrication of pocker rods at appropriate interavels to be carried
out

40. Ends not laid properly on the cone at reversal of yarn path
19

41. EFFECT
More end breaks in the subsequent process
• Excessive yarn waste
CAUSES Vibrating and wrongly set cone holder
 Yarn coils wrapped round the base of cone holder
 Traverse restrictors fixed at incorrect position
 Improper alignment of tension brackets with the drum
RECTIFICATION
Maintenance cone winders to be good
1. Cone holder settings and alignment of tension
2. Brackets with drum to be carried out as frequently as possible

42. Formation of ribbon like structure on the circumference of the cone
20

43. EFFECT
High level of slough off during unwinding
•Excessive yarn waste
•Uneven dye pick up in the case of dye packages
CAUSES Winding spindle not revolving freely
Cone holders incorrectly set
Defective settings of cam switch
Lint accumulation in builder cam groove
RECTIFICATION
Over hauling of cone winders to be periodically carried out
1. Anti ribboning mechanism to be checked at frequent interval
2. Free movement of the cone holders to be ensured by proper
lubrication

44. Unduly soft structure of cone
21

45. EFFECT
Overall density of package is lower
•Soft packing either at the base or at the nose of cones
CAUSES Improper alignment of winding spindle to the winding drum
Insufficient unwinding tension
Inadequate cradle loading
RECTIFICATION
Unwinding tension to be maintained at 6 to 8% of single yarn strength
1. Cradle pressure to be maintained to the optimum level

46. Cones which are tightly built at centre, presents a shape of bell
22

47. EFFECT
Excessive breaks during subsequent processes
CAUSES High yarn tension during winding
Cone holders incorrectly set to the winding drum
Damages in paper cone centre
RECTIFICATION
Quality of cones to be checked at that time of procurement
1. Optimum unwinding tension to be maintained

48. Bulging of bunches of the yarn at the nose of the cones
23

49. EFFECT
Slough during warping/unwinding
•Excessive yarn waste in next process
CAUSES Improper setting of cone holders to the winding drum
Damaged nose of the paper cones
RECTIFICATION
Periodical inspection of settings in winding machines
1. Tenters to be instructed to adopt correct work practices
2. Avoiding usage of damaged paper cones

50. Collapse of the structure of the cone(paper cone)itself
24

51. EFFECT
Use of poor quality /damaged paper cones
•Poor system of material handling
•Maintaining non optimum unwinding tension
CAUSES Use of poor quality/damaged cones
RECTIFICATION
Using of poor quality/damaged paper cones should be avoided
1. Winding tenters should be trained by proper work methods
2. Proper material handling devices such as cone transport trolleys
to be used
3. Cone inserts to be used for paper cones

53. Faults: miss-shaped laps.
Remedy:
•If the censity of cotton across the width of the laps is constant ,wedge
shaped laps can still occur due to unequal pressure on side of the
calendar r/r.
•Pressure should be equal on both sides.
Faults: split laps.
Remedy:
•If lap licking at the card persists, it can be prevented by feeding roving
into the lap sheet as it is formed at the lap end or by use of lap r/r.

54. Faults: Poor cleaning efficiency.
Remedy:
•In the m/c cleaning efficiency is affected by grid bar to beater settings,
better speeds, condition of beater blade edges and beater bars, fan speed
and m/c cleanliness.
•Appropriate stapes have to be taken.
Faults: Neps Formation
Remedy:
•The paddle regulator mechanism and cone drum drive should be kept in
good working order.

56. Faults: neppy web.
Remedy:
• The m/c made neps may be due to an excessive number of immature
fibres in the cotton or to poor settings and maintenance. Which should be
properly maintained.
Raw materials:
•Checking that the belts are correctly mixed according to micronaire value
and fibre bundle strength.
•Percentage of wastage should be maintained accordingly.
Faults: cloudy web.
Remedy:
•Correct settings of back sheet.
•Poor condition of wire with patches missing, damaged or rubbed will have
the same results which should be maintained.

57. Faults: Irregular sliver.
Remedy:
•Any eccentric r/r, incorrect undergrid settings, rubber wire across the
eccentric r/r settings should be on the points.

59. Faults: fine sliver.
Remedy:
•All drawframe stop mechanism should be regularly tested.
Faults: irregular sliver.
Remedy:
•Checking top and bottom r/r, top spinning pressure and r/r
settings and taking suitable action.
•Also checking that sliver is not being reserved.

61. Faults: Neppy waste.
Remedy:
•Top combs and cylinders should be examined daily because damaged
cylinder wire/needles and top com needles can cause flocking.
Faults: Long fibers in waste.
Remedy:
There are a number of comber settings and timings which will cause long
fibre to be found in the wastage. They include insufficient of the nippers
during feeding, late closing of the nippers, wide detaching r/r settings
detaching r/r turning back too late which should be properly observed.

62. Faults: Irregular sliver.
Remedy:
•R/R, r/r settings and drafts should be checked.
Faults: Curls.
Remedy:
•Correct timing of nippers and detaching r/r, correct penetration
of the top combs and r/r covering.

64. Faults: Slippings coils.
Remedy:
•Attention to finding the correct taper wheel, resetting poker bar
and the builder will cure this faults.
Faults: Soft bobbins.
Remedy:
•This faults can be prevented by using suitable change wheels. If an
odd bobbin is affected this could be due to fine a fine roving or
incorrect tensioning.
Faults : Irregular roving.
Remedy:
•Simplex m/c are susceptible to this faults and source of the
vibration is usually in the gearing or grafting r/r.

65. Faults: Count and hank variation
Variation in hank and count should be monitored and controlled as previously
specified by:
•Regular daily inspection and maintained strict control lap weights,
weekly meter/metre wrappings of scutcher laps, calculating variation
and graphing results.
•Wrapping finisher drawframe sliver every 4 hours and taking immediate
action if results exceed tolerance quality control graphs to be used.
•Daily wrappings of yarn for count, regularity of count, strength and
twist. Assessment of yarn on blackboards.
•Faults have adequately death with earlier in this section under
regularity.

67. Faults: Foreign fibers:
Remedy:
•Operatives working in the mixing chamber must be instructed to
take out any foreign fibers, string, cloth contaminated with dye or
oil.
•Care have to be taken when taking the tare from the bale.
Faults: Twist variation:
Remedy:
•Too much twist reduces yarn strength and also makes the yarn
brittle and liable to from snarls. Spindle to spindle variation also
occurs due to differences in spindle speed as a result of driving tape
slippage, misalignment of tapes and spindle bearings or inadequate
lubrication which should be maintained properly.

68. The quality control in spinning has a vital consequences on the
production. In the aspect of textile it is a must to make sure to fulfill
the general requirement of the quality in different stages in spinning.