Heavy Cotton Duck Dyeing Process Control and Levelness Optimization
Heavy cotton duck dyeing requires progressive electrolyte dosing, high-pressure liquor penetration, and strict tension control to eliminate surface ring-dyeing.
Edge-to-Center Listing
Visual Deviation
Variation in color intensity across the width of a fabric roll indicates a failure in the uniform application or fixation of dyes during the finishing process. Presence of edge-to-center listing typically appears as a darker or lighter shade at the selvedge compared to the middle of the web. Shading discrepancies render the fabric unusable for garment patterns that span the full width of the cloth.
Mechanical Origin
Machine settings on a continuous dyeing range or a stenter frame often drive this inconsistency. Uneven pressure across the padding rollers or temperature fluctuations in the drying oven lead to differential dye migration. Rollers that are slightly bowed or have worn surfaces fail to apply the liquor with the necessary precision.
Detection Method
Inspection involves taking swatches from the sides and the center of the roll for side-by-side comparison under standardized lighting. Quantitative measurement of edge-to-center listing uses a spectrophotometer to check if the variation exceeds a set threshold. If the color difference is visible to the naked eye, the fabric is downgraded to seconds.
Prevention Strategy
Regular maintenance of the padding mangle and monitoring of the airflow in the dryer prevent the development of these shade gradients. Proper fabric tensioning also ensures that the dye liquor penetrates the structure evenly from one side to the other.