Faults in knit dyed fabric

1. Faults in Knit Dyed Fabric

2. PREPARED BY ©right Name : MAZADUL HASAN SHESHIR ID: 2010000400008 Batch: 13th Batch (Session 2009-2013) Department: Wet Processing Technology Email: mazadulhasan@yahoo.com Blog: www. Textilelab.blogspot.com Southeast University Department of Textile Engineering

3. Knitting faults

4. Yarn dust Causes of faults: -  Fly yarn/ foreign fiber Remedies: -  Proper air suction

5. Set-up Causes of faults: -  For badly needle break  Yarn break Remedies: -  Remove bad needle  Maintain proper tension

6. Loop mark Causes of faults: -  Defective needle  Not properly needle latch work Remedies: -  Change new needle  By clean needle latch, hook

7. Needle break Causes of faults: -  High yarn tension  Bad setting of the yarn feeders  Old and worn out needle set Remedies: -  Ensure uniform and right yarn tension on the feeders  Keep the recommended gap between the yarn feeders and the needles  Periodically change complete set of needles

8. Oil spot Causes of faults: -  Due to contact with oil or grease covered exposed m/c parts  Careless handling could be another cause Remedies: -  Use of strong knitting oil which can be removed  After every process, if possible check filter and clean it

9. Thick place Causes of faults: -  Different yarn count  Use unmatured fiber Remedies: -  Select matured fiber  Check /indentify the yarn thick/thin place

10. Mix yarn/Lot mix Causes of faults: -  Unawareness of operator Remedies: -  Awareness in production

11. Hole 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

12. 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

13. Yarn contamination Causes of faults: -  Presence of dead fibers and other foreign materials  Presence of the foreign materials, in the stable fiber mixing Remedies: -  Use rich fiber mixing for the yarns  Segregate the knitting m/c with mosquito nets to prevent the fibers flying from neighboring

14. 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

15. 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

16. Dyeing faults

17. Uneven dyeing Causes of faults: -  Inadequate scouring of the grey fabric  Correct pH value not maintained  Water hardness  Improper neutralization  Improper migration Remedies: -  Scour the grey fabric thoroughly, to remove all the impurities from the fabric  Maintain the correct pH value  Maintain water hardness  Proper neutralization  Proper migration

18. 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

19. 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  Water hardness Remedies: -  Use a power back up for the dyeing operation to be completed uninterrupted  Maintain correct pH value  Use appropriate leveling agents  Maintain water hardness

20. Dye spots Causes of faults: -  Colored spots due to dye deposits on the m/c Remedies: -  Pay attention to cleanness in the m/c

21. Pilling Causes of faults: -  Due to friction of fabric  Poor yarn quality Remedies: -  Need good enzyme treatment  By using combed yarn

22. Uneven dyeing Causes of faults: -  Improper migration  Improper neutralization  Inadequate scouring of the grey fabric Remedies: -  Scouring the grey fabric thoroughly  Proper migration  Proper neutralization

23. Soda spot Causes of faults: -  Improper dosing of soda Remedies: -  Proper dosing of soda

24. Finishing fault of knit dyeing fabric

25. Uneven Causes of faults: -  Unstable dye dispersion  Dispersing agent not enough  Wrong temperature Remedies: -  Select dyes with better dispersion stability  Proper temperature maintained

26. Skew Causes of faults: -  Over width for this fabric Remedies: -  By using weft straightening device  Maintain proper width

27. Slitting fault Causes of faults: -  It is causes due to operator carelessness Remedies: -  Operators have to slit fabric through slitting mark

28. Uneven brushing Causes of faults: -  Not proper soft  Roller pins problem Remedies: -  Use softener  Check pins

29. 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

30. Unwanted mark Causes of faults: -  Due to contact with oil or grease covered exposed m/c parts  Careless handling could be another cause Remedies: -  Use of strong oil which can be removed  Proper handling should be taken

31. Oil mark Causes of faults: -  Due to contact with oil or grease covered exposed m/c parts  Careless handling could be another cause Remedies: -  Use of strong oil which can be removed  After every process, if possible check filter and clean it

32. 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

33. Silicon mark & Burn effect Causes of faults: -  Long time deposit of solution  Improper mixing  For over or high temperature this burn effect is visible  Twice stenter Remedies: -  Proper mixing  Select suitable silicon  Maintain correct temperature

34. Line mark Causes of faults: -  This mark are caused due to the excessive pressure of the roller Remedies: -  Pressure of roller should be maintained  Take care of fabric

35. Burning effect Causes of faults: -  For wrong temperature  Unawareness of operator Remedies: -  Maintained proper temperature  By using experienced manpower

36. Chemical spot Causes of faults: -  Improper mixing of chemical  Weak chemical  Unawareness of operator Remedies: -  Proper mixing of chemical  Use appropriate chemical  By using experienced manpower

37. Uneven brushing Causes of faults: -  Too much pressure of the cylinder roller is the causes Remedies: -  Operator should take care when fabric is running  Uniform motion  R.P.M should maintained

38. Uneven brushing Causes of faults: -  Too much pressure of the cylinder roller is the causes Remedies: -  Operator should take care when fabric is running  Uniform motion  R.P.M should maintained

39. Sewding fault Causes of faults: -  Wrong m/c set up  Over speed /r.p.m  Displace of pin Remedies: -  Installed proper m/c set up  Maintain correct cylinder speed  Check and proper placement of pin

40. Unwanted mark Causes of faults: -  Due to contact with iron rust from m/c parts  If fabric wet long time  Unclean roller or padder Remedies: -  Try to clean m/c parts  Keep fabric dry  Clean roller and padder