Dyeing Defects/Faults | Causes of Dyeing Defects | Name of Dyeing Defects

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Dyeing Defects:
During dyeing a number of defects occur. These defects are classified into two main categories:

1. Major Defects
2. Minor Defects
Dyeing defects
Major Defect:
A defect that, if conspicuous on the finished product, would cause the item to be a second. (A "second" is a garment with a conspicuous defect that affects the salability or serviceability of the item. 
 
Minor Defect:
A defect is defined as minor defect that is not likely to reduce the usability of the product, but nevertheless may negatively influence the sales.

The minor defects can be untrimmed thread-ends, slight dirt in a non-noticeable zone which can be removed, etc.

Causes of Dyeing Defects:

Due to Material:
  1. Material having dead fibers or other defective fibers.
  2. Left over of Chemicals after bleaching etc.
  3. Material not properly desized.
  4. Material not properly mercerized.
  5. Absorbency of the fabric not proper.
  6. Sticking of insoluble material on the fibers.
  7. Impurities are not removed properly.
  8. Uneven heat treatment.
Due to Water Quality:
  1. More Hardness of water
  2. Water has metal ions such as iron.
  3. pH of water not proper
  4. Water having more chlorine
Due to Improper Dye Solution:
  1. Improper weight ratio of colors, material and chemicals.
  2. Improper material to water ratio
  3. Improper filtering of concentrated colors.
Name of Dyeing Defects:

1. Barre
2. Bleeding
3. Crocking
4. Shade Bar
5. Shading
6. Stained
7. Color Variation in Yarn
8. Hole in Sulfur Dyed Fabric
9. Creasing
10. Streaked 
 
A short description of dyeing defects are given below: 

Barre
  • Its horizontal shaded band across the width of the fabric.
  • It may be caused by variation in the size of the filling yarn and by the differences in tension of either the filling or warp yarns.
Bleeding
  • It’s a loss of color when the dyed fabric is wetted or emerged in water.
  • The water here, becomes colored and may cause discoloration of other fabrics.
  • This is usually due to either improper dye selection or poor dye fastness.
Crocking
  • It is the rubbing off of the color.
  • It may rub onto another fabric.
  • This may be due to inadequate scoring subsequent to dyeing.
Shade Bar
  • It is a horizontal band of a different hue running across the fabric.
  • It may be caused by a change of filling bobbin in the loom or a loom stop and start up
Shading
  • It is a variation in color tone either horizontally or vertically.
  • It is generally due to uneven tension on the fabric.
Stained
  • It indicates a discoloration caused by a foreign substance, dirt, grease, oil or sizing residue on the fabric being dyed.
Color Variation in Yarn
  • Caused due to lack of agitation in the dye bath.
  • This is a major defect. The yarn was supposed to be uniformly blue in color.
Hole in Sulfur Dyed Fabric
  • Caused due to tendering which takes place because sulphur is converted into sulphuric acid after oxidation which is harmful for the cellulosic fibers.
  • This is a major defect. The defect occurred after washing the garment.
Creasing
  • Causes unleveled penetration of dyes which in turn results into unleveled dyeing, which causes colour variation.
  • Differs from crease streak in that streak will probably appear for entire roll.
  • On napped fabric, final pressing may not be able to restore fabric or original condition. Often discoloration is a problem.
  • It refers to color that doesn't exactly match the standard or the prepared sample.
  • This may be due to faulty dye foundation or application or may be due to variation in dye lot.
Streaked
  • This type of defect on the fabric indicates either a stain or uneven dyeing caused byfolds in the fabric during the dyed process. 
 

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