Yarn Count and Sizing Chemistry in Warp Preparation
Warp sizing requires matching yarn packing factor to polymer viscosity, adjusting squeeze nip pressure for precise solids add-on, and maintaining elongation.
Ultrafiltration PVA Recovery
Polymer Recycling
Membrane-based filtration process used to concentrate and reclaim polyvinyl alcohol from textile desizing wastewater reduces chemical consumption in finishing mills. Implementation of ultrafiltration pva recovery allows the mill to reuse the sizing agent for subsequent yarn preparation batches. This system filters out the large water molecules and salts while retaining the long-chain polymer molecules.
Its operation reduces the chemical load on the wastewater treatment plant.
Membrane Separation
The dilute wastewater from the desizing bath is pumped under pressure through semi-permeable membranes that have a specific molecular weight cut-off. These membranes allow the wash water to pass through as permeate, while the polyvinyl alcohol is concentrated in the retentate stream. This ultrafiltration pva recovery process must run at elevated temperatures to prevent the polymer from gelatinizing on the membrane surface.
Regular chemical cleaning is required to remove any accumulated flax waxes or pectins that can reduce the filtration rate. The recovered polymer concentrate is then blended with fresh size before being applied to the warp yarn.
Economic Benefit
Mill managers track the recovery rate using refractometers to measure the concentration of the reclaimed sizing solution. This measurement helps calculate the cost savings from reduced polymer purchases. Recycling these chemicals protects local water sources.