I. Color difference between the beginning and end (lighter and darker ends)
Cause: The dye concentration is not consistent during the dyeing process, especially noticeable in giant roll dyeing machines due to long running times and uneven dye adsorption.
Solution: Use dry cloth for dyeing to avoid uneven wetting of the cloth, which can cause differences between the edge and the center.
Install a liquid level control device and a dye liquor circulation system to ensure consistent dye concentration throughout.
When dyeing with reactive dyes, run two passes first, then increase the temperature for color fixing, ensuring the fabric is dyed at a constant concentration.
II. Color difference between the edge and the center (lighter and darker edges)
Cause: Uneven fabric width when entering the dyeing machine, excessive curvature of the fabric stretching frame, or inconsistent temperature/pH values between the edge and the center.
Solution: Ensure even fabric width when winding to avoid a "bulging belly" phenomenon.
Select dyes with similar dyeing temperatures to reduce the impact of temperature differences between the edge and the center. Strengthen pretreatment to ensure uniform pH across the entire fabric.
III. Color Variation and Weft Skew
Causes: Excessive heating rate, insufficient dye dissolution, or asynchronous dyeing and fixing.
Solutions: Control the heating rate after 80℃ to avoid excessively rapid dyeing in high-temperature zones.
Use compatible dyes to prevent weft skew caused by secondary dyeing.
Dyes must be filtered before use and manually stirred to ensure complete dissolution.
IV. Overlap Marks
Causes: Seams are too wide or thick, causing compression after being rolled onto the roller, or significant color/texture differences between the guide fabric and the dyed material.
Solutions: Seams should not be too wide; make a few cuts at the seam to prevent water accumulation.
Ensure the guide fabric and dyed material have similar colors and uniform textures to avoid differences in liquid absorption.
V. Wrinkles and Weft Skew
Causes: Excessive tension, strong water jet impact, or uneven dyeing process.
Solutions:
Adjust tension to a moderate level and keep the fabric stretcher horizontal.
Avoid excessive steam during boiling dyeing to reduce impact.
Ensure even hand movements when loading the dye bath to prevent weft skewing.
6. Loose board printing
Causes: Excessive tension and temperature during fabric winding.
Use cold water for winding to avoid high-temperature setting.
Control winding tension to prevent excessive fabric stretching.
7.Small spots and stains on the fabric surface
Causes: Incomplete dye dissolution, cationic/anionic reaction precipitation, or inadequate equipment cleaning.
Filter dyes before use; dissolve disperse dyes in cold water.
Keep equipment clean to prevent yarn tangling or impurities.
Use cationic/anionic auxiliaries in different baths, or add an anti-settling agent.
