Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Faults & remedies/preventive measures in knitted fabric dyeing

1,786 views

Published on

This ppt elaborates the detail Faults & remedies/preventive measures in knitted fabric dyeing industry.it is very helpful!

Published in: Engineering

Faults & remedies/preventive measures in knitted fabric dyeing

  1. 1. SOUTHEAST UNIVERSITY DEPARTMENT OF TEXTILE ENGINEERING KNIT DYEING FAULTS & REMEDIES
  2. 2. 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.
  3. 3. UNEVEN DYEING. Causes: • Uneven pretreatment (uneven scouring & bleaching). • Improper color dosing. Remedy: • By ensuring even pretreatment. • Proper dosing of dyes and chemicals.
  4. 4. 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.
  5. 5. 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.
  6. 6. 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.
  7. 7. BATCH TO BATCH SHADE VARIATION Causes:  Shade variation can be as a result of mixing of the fabrics of two different lots.  Shade variation is also caused by the variation in the process parameters i.e. Time, Temperature & Speed etc. from one fabric roll, to the other.
  8. 8. CONT... Remedies:  Ensure that the grey fabric used for one shade is knitted from the same lot of the yarn.  Ensure that the same process parameters (Width, Overfeed, Temperature & Machine Speed etc.) are used, for each roll of a dye lot.
  9. 9. 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.
  10. 10. FABRIC HOLE. causes: • More acid of knit fabric in the dyeing section. • Temperature highly. Remedy: • Use standard Acid. • Proper dosing of Acid.
  11. 11. PIN HOLE DAMAGE: Causes:  Oxidation of the knitting oil/lubricant on the fabric stored for a long duration.  Presence of sharp metallic part in some parts of machine  Presence of heavy metal ions in peroxide bath. Remedies:  Check presence of any sharp object in machine  Provide magnetic filters in water/ steam line
  12. 12. CREASE MARK: Causes:  More cycle time.  Faulty plaiting device.  Slack on tight selvedge causes creases at an angle to each selvedge.  Incorrectly set bowed-expander.  Variation of heating and cooling rate.  Improper fabric movement. Remedy:  Anti- creasing agents are used to avoid crease mark problem.
  13. 13. DYE SPOTS Causes:  These are most often caused by operators not correctly mixing and thoroughly dissolving the dyestuff, in the right amount of water.  Dye bath hardness.  Not agitation of dyestuff. Remedies:  Use adequate amount sequestrate to lower bath hardness.  Proper agitation.

×