SPINNING & YARN FAULT

SPINNING & YARN FAULTS

Prepared By : Mazadul Hasan sheshirID: 201000040000813th Batch Wet Processing Technology Email: mazadulhasan@yahoo.comSoutheast University

Southeast University Department Of Textile Engineering

I/A 251,252 Tejgaon Dhaka Bangladesh

Prepared By :

YARN FA

ULT

LOW COP CONTENTYarn content in the cop is less

1

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

SLUBSAn abnormally thick place or lump in yarn showing less twist at that

place.

2

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.

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

NEPS

3

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.

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

SNARL

4

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

Measurable by Uster Imperfection Indicator and observable on appearance

THICK AND THIN PLACES

5

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

Yarn which is weak indicating lesser twist

SOFT YARN

6

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

Yarn stained with oil

OIL STAINED YARN

7

EFFECT Damaged fabric appearance

• Occurrence of black spot in fabric

CAUSESCareless 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

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

CRACKERS

8

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

Unduly thick piecing in yarn caused by over End piecing

BAD PIECING

9

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

Slub in the yarn stained with oilOILY SLUB

10

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

Presence of black specks of broken seeds, leaf bits and trash in yarnKITTY YARN

11

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

Protrusion of fibre ends from the main yarn structureHAIRINESS

12

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

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

FOREIGN MATTERS

13

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

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

SPUN IN FLY

14

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

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

CORK SCREW YARN

15

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

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

SLOUGH OFF

16

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

Damaged layers on the surface of the ring cops

RING CUTS

17

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

Step-like appearance of the cop

IMPROPER BOBBIN BUILD

18

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

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

STITCHING ON CONE

19

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

Formation of ribbon like structure on the circumference of the cone

RIBBON WOUND CONE

20

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

Unduly soft structure of cone

SOFT BUILD CONE

21

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

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

BELL SHAPED CONE

22

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

Bulging of bunches of the yarn at the nose of the cones

NOSE BULGING

23

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

Collapse of the structure of the cone(paper cone)itself

COLLAPSED CONE

24

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

BLOW ROOM FAULT

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.

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 FormationRemedy:

•The paddle regulator mechanism and cone drum drive should be kept in

good working order.

CARDING FAULT

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.

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

DRAWFRAMES FAULT

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.

COMBERS FAULT :

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.

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.

SIMPLEX FAULT

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.

Faults: Count and hank variationVariation 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.

RINGFRAME FAULT

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.

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.

CONCLUSION:

REFERENCE :

vijayakumhark.tripod.com