Shortwave Infrared Band Selection for Cotton Contaminant Removal
Targeting 1450 nm and 2200 nm shortwave infrared bands differentiates polypropylene and organic contaminants from cotton lint with high optical contrast.
Water Regain
Moisture Equilibrium
Standardized mass percentages quantify the dry weight basis ratio of absorbed water held by a textile material under controlled atmospheric conditions. Laboratory moisture testing determines water regain by weighing a textile sample, drying it completely in an oven, and comparing the moisture weight against oven dry weight. Hygroscopic fibres like wool and viscose exhibit high moisture absorption due to accessible hydrophilic sites along their molecular chains.
Complete fiber submergence in liquid water changes the physical system to liquid pick up, defining the boundary where regain calculations stop applying.
Commercial Weight
Commercial transactions for raw fiber, yarn packages and woven fabric rely on official standard regain allowances established by international standards organizations. Buyers and sellers calculate commercial invoice weights using water regain values determined in conditioning testing laboratories operating at twenty degrees Celsius and sixty five percent relative humidity. Adding standard regain allowances to oven dry fiber weights ensures fair billing regardless of environmental ambient humidity shifts during transit.
Fiber Behavior
Absorbed water alters mechanical properties across all natural and regenerated fiber types. Higher water regain values increase cotton fiber tenacity while reducing the dry breaking strength of regenerated viscose filaments during wet processing.
Process Control
Textile processing mills track ambient relative humidity inside spinning and weaving halls to maintain target moisture levels in running yarns. Controlling water regain reduces static charge generation, improves yarn elasticity and minimizes end breaks on high speed production machinery.