Reconciling Wet Processing Weight Loss against Finished Commercial Invoice Mass in Woven Sourcing
Reconciling woven fabric invoices requires deducting size solids and applying standard moisture regain to oven-dry mass before validating linear yield.
Caustic Weight Reduction
Chemical Modification
Controlled hydrolysis of polyester fibres using sodium hydroxide alters the surface and reduces the mass of synthetic fabrics. This caustic weight reduction improves the hand and drape of the material by creating micro-voids on the filament surface. It must be precise.
Tensile strength testing validates that the fabric retains sufficient integrity for its intended use.
Processing Sequence
Continuous or batch machines apply the alkaline solution at elevated temperatures to ensure uniform penetration. Concentration levels and dwell times determine how much polymer the caustic weight reduction removes from the outer shell of each fibre. Precise control of the liquor ratio prevents uneven patches where the chemical activity might be higher or lower than the bulk average.
Overexposure results in brittle yarns that cannot withstand downstream garment construction.
Verification Method
Measurement of the dry weight before and after the treatment provides the primary metric for process success. Lab technicians compare these values to confirm that the caustic weight reduction falls within the specified tolerance range for the order. Tensile strength testing validates that the fabric retains sufficient integrity for its intended use.
Surface Effect
Altering the cross-section of the filaments changes how the fabric interacts with light and skin. Because caustic weight reduction creates a pitted texture, the resulting fabric exhibits a matte appearance and a softer touch. These changes are permanent and do not wash out during laundry cycles.