Dyeing Defects:
Defects that occur in the fabric during the dyeing process are called dyeing defects. There are a number of problems of the reproducibility and difficulties in obtaining right-first-time dyeing. It is important that the general precautions should be followed while dyeing a textile material. Dyeing process needs very vigilant control on the dyeing conditions, like the temperature, time, color concentration and ratios, chemicals used, and the material to liquor ratio, to ensure even shade in the batch.
Dyeing defects are classified into two main categories:
- Major Defects
- Minor 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 in Fabric:
Dyeing defects may occur due to many reasons such as the following:
A. Due to Material:
- Material having dead fibers or other defective fibers.
- Left over of Chemicals after bleaching etc.
- Material not properly desized.
- Material not properly mercerized.
- Absorbency of the fabric not proper.
- Sticking of insoluble material on the fibers.
- Impurities are not removed properly.
- Uneven heat treatment.
B. Due to Water Quality:
- More Hardness of water
- Water has metal ions such as iron.
- pH of water not proper
- Water having more chlorine
C. Due to Improper Dye Solution:
- Improper weight ratio of colors, material and chemicals.
- Improper material to water ratio
- Improper filtering of concentrated colors.
D. Due to Shortcomings in the dye machinery:
- Coming out of Dye liquor during dyeing
- Defective instruments controlling temperature, pressure speed etc.
E. The dyeing procedure did not take place properly
F. The fabric was not prepared properly before dyeing
List of Dyeing Defects in Fabrics and Textiles:
During dyeing a number of defects occur. Common dyeing defects are point out below:
- Barre
- Bleeding
- Uneven Dyeing / Dye mark
- Color Crocking
- Patchy dyeing
- Shade Bar
- Bad selvedge
- Shade Variation / Reproducibility
- Stained
- Softener Marks
- Color Variation in Yarn
- Side to side variation in tone
- Hole in Sulfur Dyed Fabric
- Tailing effect
- Creasing
- Streaked
- Drain marks
- End marks
- Dyeing abrasion
- Listing marks
- Moire
- Oxidation marks
- Rope rub mark
- Dyeing creases
- Fabric damaged
- White creases
- Dye spot
A short description of above dyeing defects are given below:
1. Barre:
Barre defect occurs in the fabric when off shaded yarns run from selvedge to selvedge after dyeing.
- 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.
- Properly relaxing the material before dyeing may be the remedies of this defect.
2. 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.
3. Uneven Dyeing / Dye mark:
Uneven dyeing defect occurs in the fabric when there is difference in the shade of the fabric through the width of the fabric.
The causes for this type of defect can be as follows:
- Improper pre-treatment on the fabric
- Irregular winding leading to channeling
- Excess foam in the dye bath
- Using incorrect dyeing program
- Air pockets in the material
Remedies of these problems:
- Select appropriate dyeing conditions and chemical mix
- Proper material winding
- Use of antifoams
- Use of wetting agents
4. Color 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.
5. Patchy Dyeing:
Improper scouring and bleaching, uneven surface of padding rollers, and folds while padding is the reasons for patchy dyeing apart from improper dissolution of dyestuffs.
Remedies:
- Selecting proper leveling agent for the process
- Thorough scouring
6. Shade Bar:
- Shade bar defect occurs in the fabric when there is a horizontal band of a different hue of the color running across the width of the fabric.
- 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.
7. Bad Selvedge:
High temperature, pre-dissolution of chemicals, slippage of goods, longer yardage for vat dyeing on jigger, selvedge remaining exposed for paf batch dyed goods and uneven fabric widths are the main reasons for bad selvedge.
8. Shade Variation / Reproducibility:
Shade variation defect occurs in the fabric when there is a difference in color of the fabric.
- It is a variation in color tone either horizontally or vertically.
- It is generally due to uneven tension on the fabric.
9. Stained:
Stain defect occurs in the fabric when there are discolored spots in the fabric. It indicates a discoloration caused by a foreign substance, dirt, grease, oil or sizing residue on the fabric being dyed.
10. Softener Marks:
Causes:
- Softener not properly dissolved in water
Remedies:
- Through scouring of the grey fabric
- Uniform softener dissolving
- Choosing correct softener as per the fabric
11. 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.
12. Side to Side Variation in Tone:
Variation in temperature across the machines, addition of chemicals at one side only and improper batch tensions are the normal reasons of variation in shade from side to side.
13. 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.
14. Tailing Effect:
Loading of long batches in dye bath, high substantive dyes for padding and level difference in padding trough are normal reasons for this defect.
15. Creasing:
- Causes unleveled penetration of dyes which in turn results into unleveled dyeing, which causes color 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.
16. Streaked:
Uneven absorption of dyestuff and particularly when dyeing fabric made of high twisted yarns and variation in yarn parameters are the normal reasons for streakiness. This type of defect on the fabric indicates either a stain or uneven dyeing caused byfolds in the fabric during the dyed process.
17. Drain marks:
Change in shade on the fold of the fabric.
18. End marks:
The change in the shade at the end of the full length is called end mark.
19. Dyeing abrasion:
White shining due to mechanical friction on the fabric is known as dyeing abrasion.
20. Listing marks:
If shade is darker near selvedge than the surface of the fabric, it is known as listing mark.
21. Moire:
When the surface of the fabric looks lighter and darker in circle form, it is called moire.
22. Oxidation marks:
It is a type of stain observed in the vat-dyed fabric.
23. Rope rub mark:
Shining due to mechanical friction on the fabric is known as rope rub mark.
24. Dyeing creases:
Colored creases on the fabric.
25. Fabric damaged:
Any type of damage, for e.g. holes, component damage, selvedge damage, etc.
26. White creases:
Shining due to mechanical friction on the fabric is known as white creases. It is visible as a long line.
27. Dye Spot:
Dye spot defect occurs in the fabric when there are spots on the surface of the fabric. Dyeing machine is not cleaned properly before dyeing and dyestuff was not properly mixed into the dye solution are the main causes of dye spot in fabric.
You may also like:
- List of Fabric Faults Created During Dyeing and Their Remedies
- Preventive Measurement of Fabric Shade Variation in Dyeing
- Control of Tailing and Listing Problems in Continuous Dyeing – a Systematic and Practical Approach
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
