Greige Preparation Parameters for Heavy Woven Cotton Twill
Preparation of heavy cotton twill requires 85-degree flame singeing, dual-dip enzymatic desizing, open-width alkaline scouring, and 28 Baumé mercerization.
Cold Pad-Batch Desizing
Chemical Treatment
Fabric preparation begins with the systematic removal of sizing agents applied to warp yarns prior to weaving. Cold pad-batch desizing is a low-energy method that uses enzymatic or oxidative agents to break down starch at room temperature. The fabric is saturated with the solution and then wound onto a batch roll for several hours.
This prolonged dwell time allows the chemicals to digest the size without the application of heat.
Process Mechanism
The impregnated fabric roll is wrapped in plastic film to prevent moisture evaporation during the reaction phase. Enzymatic reactions require a specific pH and temperature range to function effectively. By allowing the fabric to dwell for up to twenty hours, the enzymes thoroughly solubilize the starch.
Once the dwell period terminates, the fabric undergoes a hot wash to remove the degraded residues, exposing the clean cotton fiber underneath. This step is critical because any residual starch will act as a barrier to subsequent dyeing and finishing chemicals, causing uneven color or patchy spots on the finished garment.
Resource Efficiency
Modern mills adopt this method because it significantly reduces steam consumption compared to continuous desizing ranges. It decreases both carbon emissions and processing costs.
Quality Assessment
Laboratory technicians perform a Tegewa test using an iodine solution to check for starch leftovers on the washed fabric. A pale or colorless result indicates successful starch removal, while a dark blue spot shows incomplete desizing.