Faults in knit dyed fabric

- Remove bad needle Maintain proper tension... Needle breakCauses of faults: -  High yarn tension  Bad setting of the yarn feeders  Old and worn out needle set Periodically change

Faults in Knit Dyed Fabric

Name : MAZADUL HASAN SHESHIR

ID: 2010000400008

Batch: 13th Batch (Session 2009-2013)

Department: Wet Processing Technology

Knitting faults

- Remove bad needle

 Maintain proper tension

 Change new needle

 By clean needle latch, hook

Needle break

Causes of faults: -

 High yarn tension

 Bad setting of the yarn feeders

 Old and worn out needle set

Periodically change complete set of needles

 Use of strong knitting oil which can be removed

 After every process, if possible check filter and clean it

Thick place

Causes of faults: -

 Different yarn count

 Use unmatured fiber

Remedies: -

 Select matured fiber

 Check /indentify the yarn thick/thin place

Mix yarn/Lot mix

Causes of faults: -

 Unawareness of operator

Remedies: -

 Awareness in production

Causes of faults: -

 Holes are the results of yarn breakage

 Yarn tension too high

 Presence of knots in yarn

 If the yarn count is not correct

Remedies: -

 Yarn strength must be sufficient

 Maintain proper tension

 Knots should be given properly

 Use proper count of yarn

Lycra out

Causes of faults: -

 Yarn tension too high

 Lycra guide roller block or jam

 Needle not properly work

Remedies: -

 Maintain proper yarn tension

 Ensure smooth running of guide roller

 Change defective needle

 Use rich fiber mixing for the yarns

 Segregate the knitting m/c with mosquito nets

to prevent the fibers flying from neighboring

Miss yarn

Causes of faults: -

 Yarn break

 Positive feeder jam

 Excessive needle tension

 Weak yarn

Remedies:

- Yarn strength must be sufficient

 Smooth running of feeder

 Proper needle tension

Tara fault (Star)

Causes of faults: -

 For high r.p.m of m/c cylinder

 One part dyeing

Remedies: -

 Maintain proper r.p.m of m/c cylinder

 Range should be upto 23

Dyeing faults

Uneven dyeing

Causes of faults: -

 Inadequate scouring of the grey fabric

 Correct pH value not maintained

 Maintain the correct pH value

 Maintain water hardness

 Proper neutralization

 Proper migration

Uneven dyeing

Causes of faults: -

 Improper neutralization

 Improper dyes dosing

 Improper soda dosing

 Improper migration

 Improper leveling agents

Remedies: -

 Proper neutralization

 Proper dyes dosing

 Proper soda dosing

 Proper migration

 Proper leveling agents

Uneven dyeing

Causes of faults: -

 Dyeing m/c stoppage, due to power failure or the fabric entanglement in the dyeing m/c

 Correct pH value not maintained

 Improper leveling agent

 Maintain correct pH value

 Use appropriate leveling agents

 Maintain water hardness

Causes of faults: -

 Due to friction of fabric

 Poor yarn quality

Remedies: -

 Need good enzyme treatment

 By using combed yarn

Finishing fault of knit dyeing fabric

Causes of faults: -

 Unstable dye dispersion

 Dispersing agent not enough

 Wrong temperature

Remedies: -

 Select dyes with better dispersion stability

 Proper temperature maintained

Causes of faults: -

 Over width for this fabric

Remedies: -

 By using weft straightening device

 Maintain proper width

Uneven brushing

Causes of faults: -

 Not proper soft

 Roller pins problem

Remedies: -

 Use softener

 Check pins

Crease mark

Causes of faults: -

 Improper motion of padder

 Improper fabric movement

Remedies: -

 Proper motion of padder

 Ensure smooth running of fabric

 Use anti-creasing agents

 Use of strong oil which can be removed

 Proper handling should be taken

 Use of strong oil which can be removed

 After every process, if possible check filter and clean it

Silicon spot

Causes of faults: -

 Long time deposit of solution

 Improper mixing of the silicon

Remedies: -

 Proper mixing of the silicon

 Use the right silicon

 Maintain the correct pH value, before application

Silicon mark & Burn effect

 Select suitable silicon

 Maintain correct temperature

 Pressure of roller should be maintained

 Take care of fabric

 Maintained proper temperature

 By using experienced manpower

 Proper mixing of chemical

 Use appropriate chemical

 By using experienced manpower

 Installed proper m/c set up

 Maintain correct cylinder speed

 Check and proper placement of pin

Unwanted mark

Causes of faults:

- Due to contact with iron rust from m/c parts

 If fabric wet long time

 Unclean roller or padderRemedies: -

 Try to clean m/c parts

 Keep fabric dry

 Clean roller and padder