Solvent Standard
Standard test procedure ASTM D2257 quantifies solvent-soluble materials present in textile fibers and yarns. Dry ASTM d2257 extractable matter measures oils, greases, waxes, and synthetic lubricants removed by organic solvents during laboratory extraction. The measurement defines baseline cleanliness for raw materials before dyeing operations.
Gravimetric Wash
Laboratory extraction takes place inside a Soxhlet apparatus using specified organic solvents such as dichloromethane or petroleum ether. Volatile solvent vapor ascends into a condenser, drips over the fiber mass, and siphons off accumulated soluble chemicals into a boiling flask. The solvent evaporates under controlled heat until only non-volatile matter remains in a tared weighing container.
Heating cycles repeat until consecutive weighings show constant mass. This quantitative determination isolates processed spin finishes from synthetic filaments or raw cotton wax.
Residue Boundary
Water-soluble sizing compounds like starch or polyvinyl alcohol remain unaffected by organic solvents and fall outside this protocol. ASTM d2257 extractable matter excludes particulate dirt and insoluble binder residues.
Commercial Clearance
Mill specifications establish maximum allowable residue limits prior to fabric formation. Excess lubricant causes dye streaks and smoke emissions in heat-setting stenters. Insufficient lubricant leads to yarn friction and needle breakage during high-speed knitting.
Mill laboratories archive extract weight data to verify consistency across fiber lots.
