Greige Specification Parameters for Woven and Knitted Structural Engineering
Accurate greige specifications require defining relaxed loop length and conditioned thread counts rather than relying on unstable on-machine measurements.
Sizing Add-on
Polymer Addition
Starch derivatives and synthetic polymers applied to warp yarns prior to weaving form a sizing add-on, which increases tensile strength and reduces abrasion vulnerability during loom operation. Excess film formation during this application stage creates stiffness that impairs subsequent wet processing stages. Production managers calculate the dry mass increase by weighing yarn samples before and after the sizing process.
Laboratory technicians verify this deposit against purchase specifications to ensure fabric handle remains within acceptable limits during dyeing.
Rheological Control
Viscosity regulation inside the slurry tank governs pickup rates during immersion phases. High resistance to flow deposits excessive compound onto the core filaments, whereas thin mixtures fail to protect individual fibres against repeated mechanical friction. Operators adjust temperature parameters continuously to maintain consistent fluid dynamics throughout large production runs.
Extraction Mechanics
Squeezing rollers positioned immediately after the sizing bath determine the final moisture content and solid retention levels. Pneumatic pressure applied across these cylinders forces surplus liquid back into the reservoir. Worn roller surfaces create uneven film distribution across the yarn sheet, leading to warp breaks during subsequent shedding motions.
Chemical Recovery
Modern sizing operations utilize ultrafiltration systems to reclaim polyvinyl alcohol from wash water streams. Reclaimed solids return directly to preparation mixing vats without altering yarn performance characteristics. Environmental compliance mandates precise monitoring of effluent chemical oxygen demand values before discharge occurs.