• Types of Dyeing Errors : slanted lines appearing (due to the difference in shading),
                                    difference in contraction
• Possible Cause : abnormal mixture of dyes due to various factors

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• Types of Dyeing Errors : slanted lines appearing (due to shading difference), stains,
   blots, differences in color
• Possible Causes : residues of various other substances due to insufficient purification
   and/or refinement; molds and fungi attributed to long-term storage

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• Types of Dyeing Errors: stains, blots, contamination, tarring, color differences
• Possible Causes : misuse of water, dyestuffs, and/or silicon-based antifoaming
  agents; aged dyeing machines; incomplete washing inside the dyeing machine;
  contaminated waxes; wrong handling (temperature rise speed, methods of adding
  agents, timing, etc.); wrong agents, etc.

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Creases created during processing the fabric may derive from various sources, including the inherent characteristics and properties of the fabric and application of the processing methods. 1. Rope-shaped Creases    As the fabric continues to roll around inside the dyeing machine, creases are narrowed and widened repeatedly. In cases where this repetition between narrowing and widening of creases does not happen, the dye unevenly distributed across the outer surface and the inner surface of the fabric rolled into a rope forms stains.      In order to solve this problem, you could either reduce the amount of fabrics you put into the dyeing machine at once so that the fabrics could move more freely, or increase the total volume of liquid inside the machine. Or, you could widen the diameter of the tube or the nozzle. You could also soften the fabric by dissolving fabric softener into the liquid. 2. Creases from Rolling    These are creases and stains created as only one corner of the fabric is rolled toward the center of the fabric two-fold or three-fold. In order to prevent formation of such creases and stains, you could slow down the speed of injecting the fabric into the dyeing machine. You could also preset the fabric to loosen its tension, or do refinement-bleaching once again. 3. Filling Creases    There are some of these creases created as the fabric is curved or compressed, but these creases are mostly created as the fabric is fixed into a position enforced by curving or compressing. In order to solve this problem, you could reduce the amount of fabrics hardened in the liquid or increase the volume of the liquid. You could also shorten the processing time at low temperatures. Use fabric softener while the fabric is in the liquid. Preset fabrics whose shapes are likely to be fixed by heat. 4. Creases from Drying    There are creases created during dehydrating and drying the dyed fabric; those created when the fabrics are spread across; and those created while the fabrics are dried.      To overcome this problem, you could change the amount of the fabrics being processed at one time, or modify the wind velocity when drying the fabrics.

Process Machines Crease Types Solutions Dehydration Dehydrator   Mangle   Filling Creases   Rope-shaped creases, creases 1) Change the amount of filling; 2) Change the rotation speed. 1) Change the mangle pressure; 2) Change the tension of the     fabric. Spreading Spreader   Scotch   Rope-shaped creases   Rope-shaped creases 1) Untangle twisted fabrics; 2) Change the tension of the     fabric. 1) Change the rotation speed; 2) Change the tension of the     fabric. Drying Tenter   Cylinder   Longitudinal creases, flow creases Longitudinal creases, flow creases 1) Change the amount of fabrics     being injected at once; 2) Change the wind velocity. 1) Change the steam pressure; 2) Change the machine speed.

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Process	Factors	Results
Dyeing	Insufficiency of penetration and diffusion Ring-dyeing	Decreased sunlight-resistance Decreased friction-resistance
Water-washing	Unfixed dyestuffs remaining Remaining acid for neutralization	Decreased waterproof quality (contamination-resistance) Promoted acid hydrolysis
Fixing	Bad fixing agent Color change due to fixing agent	Decreased sunlight-resistance Decreased chlorine-resistance
Post-Processing	Bad processing agent	Color change during processing Decreased sunlight-resistance

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• Physical Factors

1. Dyeing Machine Performance:
   a. Mixing and circulation of dye liquid
   b. Temperature inside the dyeing machine, evenness in liquid amount, etc.

2. Factors Relating to the Dyed Objects:
   a. Evenness of the fabric
   b. Types and precision of the textile structure of the fabric
   c. Density of the fabric and its distribution during washing

3. Factors Relating to Dyeing Conditions
   a. Temperature increase speed, dyeing temperature, dyeing time, methods of adding
     dyestuffs

• Chemical Factors
   Factors relating to the chemical properties of the dyestuffs and agents:
   1. Dyeing speed, applicability of mixed color dyeing
   2. Migration (directness of the dyestuffs)
   3. Relations of applicability between dyestuffs and agents

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• Differences in fabric histeresis

• Insufficient refinement
• Uneven presetting
• Color inconstancy in dyestuffs
• Unreliability of prescribed dyestuffs
• Difference in average amount between dyestuffs, agents, etc.
• Different dyeing conditions (dyeing temperature, time, etc.)
• Difference in the dyeing machine sizes
• Differences between the breaker test and the fabric dyeing machine
• Difference in the size of the fabric dyeing machine
• Different methods of drying used
• Differences due to resin processing and other chemical processes
• Color change due to heat during mechanical organizational processing except P ress.

   All these factors are possible causes for color differences. In order to prevent changes or differences in colors of final products, thorough field management and supervision are thus required.

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  Jigger dyeing machines often produce various stains in the end of the fabric, faded color in the center of the fabric, stains in both ends of the fabric, uneven length of dyeing, uneven dyeing phenomenon, and so forth. All these problems are created either when the handling process is wrong, or when the dyeing machine has problems.

      In case stains are found after dyeing, they can be fixed only by re-processing. Re-dyeing the stained fabric will damage the fabric in any form, thereby reducing its value as a product. Re-processing is also more costly than usually thought, taking into account the cost of dyestuffs and agents used again and decreased productivity.

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• These stains could be produced before dyeing, during dyeing, or after dyeing.

1. Stains before dyeing :

     - Insufficient desizing and refinement;
     - Dye stains are found due to insufficient or uneven drying after refinement.
        In case of padding-dyed fabrics, in particular, uneven moisture level deriving
        from insufficient or non-thorough dyeing create dye stains.

2. Stains During Dyeing

  Unsuitable dyeing methods or dyeing conditions: short dyeing time, overload of fabrics injected into the machine, uneven dye absorption, loop marks created as the fabric is rolled into a loop in case of winching, stains from picking the fabric up when padding-dyeing, uneven distribution heat in the thermoset method, etc.

3. After Dyeing

  Dyes may move around due to insufficient drying, color inconstancy, and uneven
  distribution of heat during heating.
  Most stains are created by insufficiency of pre-dyeing processes. Thus, these
  processes need to be managed and conducted thoroughly.

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