SPINNING & YARN FAULT

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 H

SPINNING & YARN FAULTS

Prepared By : Mazadul Hasan sheshir ID: 2010000400008

13th Batch Wet Processing Technology Email: mazadulhasan@yahoo.com Southeast University

Southeast University Department Of Textile Engineering

I/A 251,252 Tejgaon Dhaka Banglade sh

Prepared By :

YA RN

FA UL T

LOW COP CONTENT

Yarn 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

An 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

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

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

CAUSESMixing 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

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

Slub in the yarn stained with oil

OILY 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 yarn

KITTY YARN

11

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 structure

HAIRINESS

12

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

CAUSESImproper 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

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 Formation

Remedy:

•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.

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.