Quantitative Fibre Blend Composition Analysis

Quantitative fibre blend composition analysis (ISO 1833 series, 25 parts covering all major binary and ternary blend combinations) determines the percentage of each fibre component in textile blends using selective chemical dissolution followed by gravimetric weighing, with correction factors accounting for solvent attack on the residue fibre. General method (ISO 1833-1): dry specimen to constant weight at 105°C → weigh (m₁ g) → dissolve component A in reagent specified for blend type → filter, wash, dry at 105°C → weigh residue (m₂ g) → calculate: %A = (1 − m₂ × d / m₁) × 100 where d = correction factor (1.00–1.05 depending on solvent attack on residue). Key binary blend methods: PES/Co (polyester/cotton, ISO 1833-11: 75% H₂SO₄ dissolves cotton, polyester residue, d = 1.01); WO/PES (wool/polyester, ISO 1833-4: alkaline sodium hypochlorite dissolves wool, polyester residue, d = 1.00); PA/PES (nylon/polyester, ISO 1833-16: formic acid 80% dissolves nylon, d = 1.00); CO/CV (cotton/viscose, ISO 1833-2: zinc chloride/formic acid solution dissolves viscose, d = 1.02). Accuracy: ±1% for homogeneous well-prepared specimens at >10% component content. FTIR spectroscopy (Attenuated Total Reflectance ATR-FTIR, 4,000–400 cm⁻¹, 32 scans, 4 cm⁻¹ resolution, library match >95%) provides rapid semi-quantitative blend estimation in 2 minutes without chemical dissolution — useful for screening and fibre type confirmation before chemical quantification. DNA-based fibre authentication (animal fibre species: sheep, cashmere goat, vicuña by mitochondrial DNA PCR, IWTO-58) detects luxury fibre adulteration (cashmere labelled as such but containing 30–80% sheep wool) — limit of detection 5% contamination level.