Chemical Extraction
Laboratory test procedures remove processing oils and sizing materials from textile specimens to establish clean dry fibre mass. Quantitative analysis using non-fibrous matter extraction prepares yarns and fabric structures for accurate fibre content determination and moisture regain testing. Soxhlet extraction apparatus circulates organic solvents such as petroleum ether or dichloromethane through fabric samples to dissolve wax and oil additives.
The extraction process isolates non-fibrous contaminants but does not alter the underlying insoluble fibre polymers.
Analytical Procedure
Gravimetric measurement records specimen dry weight before and after solvent exposure to quantify removed non-fibrous constituents. When testing grey fabric directly from the loom, non-fibrous matter extraction quantifies applied starch sizing and synthetic lubricants that would otherwise skew chemical blend analysis. Samples undergo repeated solvent washing cycles followed by oven drying to constant mass under controlled laboratory conditions.
Precise temperature control prevents thermal degradation of synthetic fibres during drying cycles.
Residue Measurement
Weighing the evaporated solvent residue confirms the total mass of removed processing oils and finishing chemicals. Percentages calculated from extracted residues must not exceed contractually established limits for grey or scoured yarns.
Commercial Application
Purchase contracts for grey yarns and scoured wool specify maximum allowable non-fibrous content to protect downstream processing quality. Dyeing facilities perform extraction testing on incoming fabric lots to prevent sizing agents from causing uneven dye absorption. Excess non-fibrous residue results in financial debits against spinning mills or mandatory re-scouring before fabric processing continues.
