Knit Dyeing | Common Knit Dyeing Faults And Their Way Of Remedies

Knit fabric dyeing process is different from yarn dyeing or woven fabric dyeing process. During knit dyeing; some dyeing faults can be occurred due to wrong operating system. But it can be overcome by applying some techniques.

Knit Dyeing Faults and Their Way of Remedies: Common knit fabric dyeing faults and their way of remedies are given below.

Crack, Rope & Crease Marks

Causes:

  1. Poor opening of the fabric rope.
  2. Shock cooling of synthetic material.
  3. Incorrect process procedure.
  4. Higher fabric speed.

Remedies:

  1. Pre-Heat setting.
  2. Lower rate rising and cooling the temperature.
  3. Reducing the m/c load.
  4. Higher liquor ratio.
  5. Running at a slightly higher nozzle pressure.

Fabric Distortion and Increase in Width

Causes:

  1. Too high material speed.
  2. Low liquor ratio.

Remedies:

  1. By decreasing both nozzle pressure & winch speed.
  2. By using high liquor ratio.

Pilling

Causes:

  1. Too high mechanical stress on the surface of the fabric.
  2. Excess speed during processing.
  3. Excess foam formation in the dye bath.

Remedies:

  1. By using of a suitable chemical lubricant.
  2. By using antifoaming agent.
  3. By turn reversing the Fabric before dyeing.

Running Problem

A. Ballooning:

Causes: Seam joining with too densely sewn.

Remedies: By cutting a vertical slit of 10-15 cm in length for escaping the air.

B. Intensive Foaming

Causes: Pumping a mixture of air and water.

Remedies: By using antifoaming agent.

Uneven Dyeing

Causes:

  1. Uneven pretreatment (uneven scouring, bleaching & mercerizing).
  2. Uneven heat-setting in case of synthetic fibers.
  3. Quick addition of dyes and chemicals.
  4. Lack of control of dyeing machine.

Remedies:

  1. By ensuring even pretreatment.
  2. By ensuring even heat-setting in case of synthetic fibers.
  3. By slow addition of dyes and chemicals.
  4. Proper controlling of dyeing machine.

Shade variation (Batch to batch)

Batch to batch shade variation is common in exhaust dyeing which is not completely avoidable. Even though, to ensure a consistent batch to batch production of shade the following matters should be controlled carefully-

  1. Use standard dyes and chemicals.
  2. Maintain the same liquor ratio.
  3. Follow the standard pretreatment procedure.
  4. Maintain the same dyeing cycle.
  5. Identical dyeing procedure should be followed for the same depth of the shade.
  6. Make sure that the operators add the right bulk chemicals at the same time and temperature in the process.
  7. The Ph, hardness and sodium carbonate content of supply water should check daily.

Dye Spot

Causes: Improper mixing of dyestuff in the solution, in right amount of water, at the temperature.

Remedies: We should pass the dissolved dyestuff through a fine stainless steel mesh strainer when adding it to the chemical tank, so that the large un-dissolved particles are removed.

Patchy Dyeing

Causes:

  1. Uneven heat in the machine.
  2. Improper impregnation of dye liquor due to the low wetting property of the fabric.
  3. Dye migration during intermediate dyeing.

Remedies:

  1. By proper pretreatment.
  2. By adding extra wetting agent.
  3. Heat should be same throughout the dye liquor.

Specky Dyeing

Causes:

  1. Excessive foam in the dye bath.
  2. Fall of water droplets on fabric surface before or after dyeing.
  3. In sufficient after treatment.

Remedies:

  1. By using antifoaming agent.
  2. Sufficient after treatment.
  3. By using a good wetting agent in the dye bath.

Roll to Roll Variation or Meter to Meter Variation

Causes:

  1. Poor migration property of dyes.
  2. Improper dyes solubility.
  3. Hardness of water.
  4. Faulty m/c speed, etc

Remedies:

  1. Use standard dyes and chemicals.
  2. Proper m/c speed.
  3. Use of soft water.

Crease Mark

Causes:

  1. Poor opening of the fabric rope.
  2. Shock cooling of synthetic material.
  3. If pump pressure & reel speed is not equal
  4. Due to high speed m/c running.

Remedies:

  1. Maintaining proper reel sped & pumps speed.
  2. Lower rate rising and cooling the temperature.
  3. Reducing the m/c load.
  4. Higher liquor ratio.

Dye Spot

Causes:

  1. Improper Dissolving of dye particle in bath.
  2. Improper Dissolving of caustic soda particle in bath.

 Remedies:

  1. By proper dissolving of dyes & chemicals.
  2. By passing the dissolved dyestuff through a fine stainless steel mesh strainer, so that the large un-dissolved particles are removed.

Softener Mark

Causes:

  1. Improper mixing of the Softener.
  2. Improper running time of the fabric during application of softener.
  3. Entanglement of the fabric during application of softener.

Remedies:

  1. Maintaining proper reel sped & pumps speed.
  2. Proper Mixing of the softener before addition.
  3. Prevent the entanglement of the fabric during application of softener.

So, we should be careful about the knit dyeing faults as well as yarn dyeing faults.

One thought on “Knit Dyeing | Common Knit Dyeing Faults And Their Way Of Remedies

Leave a Reply

Your email address will not be published. Required fields are marked *


*