2. SOUTHEAST UNIVERSITY
DEPARTMENT OF TEXTILE ENGINEERING
KNIT DYEING FAULTS & REMEDIES
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 Bangladesh
3. WHY DYEING FAULTS OCCURS:
Why Dyeing Faults occurs:
While dyeing, large volume of dyestuff, thickening
agent and small amount of water are used. Many textile
chemicals like Dispersing agent, Leveling agent, Acid
buffer etc are used during the process. The dyestuff
have to be either fermented (for natural dye) or
chemically reduced (for synthetic vat and sulfur dyes)
before being applied. This makes the dye soluble so
that it can be absorbed by the fiber. Direct dyes are
water soluble and can be applied directly to the fiber
from an aqueous solution. Most other classes of
synthetic dyes, other than vat and sulfur dyes, are also
applied in this way.
4. EXAMPLE OF DYEING FAULTS
Uneven dyeing.
Running shade.
Batch to batch shade variation.
Patchy dyeing effect.
Roll to roll variation or Meter to meter
variation.
Crease / Wrinkle mark.
Dye spot.
Softener mark.
Fabric hole.
5.
6.
7. Uneven dyeing.
Causes:
• Uneven pretreatment (uneven scouring & bleaching).
• Improper color dosing.
Remedy:
• By ensuring even pretreatment.
• Proper dosing of dyes and chemicals.
Batch to Batch Shade variation:
Causes:
• Fluctuation of Temperature.
• Improper dosing time of dyes & chemicals.
Remedies:
• Use standard dyes and chemicals.
• Maintain the same liquor ratio.
8. Patchy dyeing effect.
Causes:
• Faulty injection of alkali.
• Due to improper salt addition.
Remedy:
• Proper dosing of dyes and chemicals.
• Heat should be same throughout the dye liquor.
Roll to roll variation or Meter to Meter variation:
Causes:
• Poor migration property of dyes.
• Improper dyes solubility
Remedies:
• Use standard dyes and chemicals.
• Proper m/c speed.
9. Crease mark:
Causes:
• If pump pressure & reel speed is not equal.
• Poor opening of the fabric rope.
Remedy:
• Maintaining proper reel sped & pump speed.
• Lower rate rising and cooling the temperature.
Dye spot:
Causes:
• Improper Dissolving of dye particle in bath.
• Improper Dissolving of caustic soda particle in bath.
Remedies:
• By proper dissolving of dyes & chemicals.
• By passing the dissolved dyestuff through a fine
stainless steel mesh strainer, so that the large un-dissolved particles are
removed.
10. Crease/Wrinkle mark:
Causes:
• Poor opening of the fabric rope.
• Shock cooling of synthetic material.
Remedies:
• Maintaining proper reel speed & pump speed.
• Lower rate rising and cooling the temperature.
Softener Mark:
Causes:
• Improper mixing of the Softener.
• Improper running time of the fabric during
application of softener.
Remedies:
• Maintaining proper reel sped & pump speed.
• Proper Mixing of the softener before addition.
11. Fabric hole.
causes:
• More acid of knit fabric in the dyeing section.
• Temperature highly.
Remedy:
• Use standard Acid.
• Proper dosing of Acid.
Some other faults
1. Long mark
2. Loop mark
3. Dhappa spot
4. Yellow spot
5. Iron spot
6. Out color
7. Enzyme dust
8. Fly we
9. Brush problem
10.Uneven even hairiness
11. Water spot
12. soda spot
13. Lycra out
14. Patta fault
13. Fabric Fault Inspection:
The inspection of fabric is a procedure by which the defects of
fabric are identified and fabric is classified according to
degree or intensity of defects. The fabric inspection is done
for both grey and finished fabric.
Fabric inspection :
Two ways of grey fabric inspection used to done bya) Auto turning fabric inspection m/c.
b) Varivide colour assessment cabinet –2
D-65, TL-84, TL-83,
Florescent, UV.
14. Conclusion
Fabric and Garments defect are the most important in garments
factory. It is very harmful for garments industries. Considering the
objective of the work, a systematic investigation on ‘Knit dyeing
Faults and Remedies’ were performed in the training period. All
the activities had been done maintaining in sequence of the
machinery of the production. There are many common defects
which are continually detected in the fabrics which are described
in Methodology. The purpose of our project is identifying the faults
of fabric and garments. We were identifying the fabric and
garments faults very closely and very carefully.
