ISO 105-C06 Accelerated Washing Fastness Test
topic
ISO 105-C06 accelerated washing fastness test simulates domestic laundering conditions in a Launder-O-Meter (SDL Atlas, LOM, 40 stainless steel balls, 40 rpm rotation) or Gyrowash (SDL Atlas, equivalent test without balls using eccentric rotation): 100 mL test liquor containing SDC ECE reference detergent (4 g/L), sodium perborate monohydrate for oxidative bleach conditions (1 g/L for A2S, B2S conditions), specimen (100 mm × 40 mm) sewn to multifibre adjacent fabric (DW or TV), sealed in stainless steel container (500 mL capacity). Test conditions by washing temperature corresponding to care label claim: A1S (40°C, 30 min, 10 steel balls) for 40°C machine wash claim; B2S (50°C, 45 min) for 50°C; C2S (60°C, 30 min) for 60°C; D3S (70°C, 30 min) for 70°C; E2S (95°C, 60 min) for 95°C boil wash. After test: rinse in 100 mL distilled water twice at test temperature, spin-dry, line dry at <60°C. Assessment of dried specimen and multifibre adjacent fabric: colour change of specimen (ISO 105-A02 grey scale, grades 1–5) and staining of each of 6 adjacent fibre strips (ISO 105-A03 grey scale). Dye class fastness to C06 at 40°C: reactive dyes on cotton (well-fixed) grade 4-5 colour change, 3-4 cotton staining; direct dyes on cotton (unfixed) grade 2-3 (poor); acid dyes on nylon grade 3-4; disperse dyes on polyester grade 4-5 (excellent). Sodium perborate effect (A2S versus A1S): oxidative bleach in A2S degrades vat and reactive dyes by 0.5–1.0 grade versus A1S — important for specifying correct test variant matching actual care label claim (products labelled 'do not bleach' need only A1S testing). Launder-O-Meter ball number standardisation: ISO 105-C06 specifies 10 or 40 balls depending on condition — 40 balls increases mechanical agitation severity simulating drum machine washing versus handwash.
Role
ISO 105-C06 is the globally dominant washing fastness test method, referenced in virtually every apparel purchase specification worldwide — the test condition selection (A1S through E2S) must precisely match the garment care label claim to generate legally and commercially valid fastness data, making correct condition selection the critical methodological decision that determines whether test results accurately reflect in-use consumer washing behaviour.