ISO 1833-20

Residue Gravimetry

Dry mass determination establishes the exact proportion of each polymer present in a sample. Technicians weigh dried specimens on analytical balances before and after applying specific chemical reagents. Temperature control during the extraction phase prevents thermal alteration of sensitive synthetic fibers.

Final calculations compare dry weights to identify mass loss percentages against established commercial tolerances.

Reagent Specificity

Chemical agents must selectively dissolve target polymers while leaving co-existing fibers completely unaffected. Acetone dissolves acetate fibers rapidly during the initial extraction cycle without altering adjacent chlorofiber components. Incorrect solvent selection compromises the entire analytical outcome by dissolving secondary yarn elements prematurely.

Laboratory supervisors verify reagent purity regularly to maintain strict repeatability across commercial test batches.

Interference Limits

Complex finishes and applied coatings disrupt mass loss calculations if technicians fail to remove auxiliary substances prior to testing. Specialized extraction pretreatments eliminate spin finishes, size, and non-fibrous matter before the primary solvent procedure begins. Multi-layer woven constructions require mechanical separation of distinct yarn systems before individual component testing proceeds.

Standardized protocols define clear procedural boundaries where chemical dissolution yields unreliable data due to excessive polymer degradation.