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.
Chemical Stripping Rework
Removal Nature
Removal of applied colorants from a textile substrate occurs when a dyed or printed batch fails to meet the required color specification or uniformity standards. Execution of chemical stripping rework involves the use of reducing or oxidizing agents to break the molecular bonds of the dye. The procedure returns the fabric to a base state suitable for redyeing.
Process Mechanism
Success depends on the specific dye class used during the initial application. Reactive dyes on cotton often require a combination of sodium hydrosulphite and caustic soda at high temperatures to decouple the covalent bonds. Disperse dyes on polyester might necessitate carrier-assisted stripping or high-pressure treatments to migrate the pigment out of the synthetic fibre.
Material Impact
Aggressive chemical environments used during these corrective cycles often degrade the physical integrity of the yarn. Loss of tensile strength or increased hairiness results from prolonged exposure to high pH levels or extreme thermal conditions. Quality control checkpoints must verify that the fabric still meets the original burst strength and pilling resistance requirements after the stripping is complete.
Commercial Limit
Cost analysis determines whether a batch is stripped or sold as a lower grade. Most commercial mills limit chemical stripping rework to a single attempt because multiple cycles jeopardise the hand feel and dimensional stability of the goods.