Overview
EN ISO 105-Z06:2000 (ISO 105‑Z06:1998) is an international textile test method for evaluating dye and pigment migration from pad liquors. The standard defines laboratory procedures to determine how colorants (dyes or pigments), and any migration inhibitors or auxiliaries in a pad liquor, move within or between textile substrates during drying. Results can be obtained by visual assessment or by reflectance measurement.
Key topics and technical requirements
- Scope: Assesses migration propensity of pad liquor systems containing colorants and optional migration inhibitors, thickeners or electrolytes.
- Principle: A padded fabric sample is partially covered during drying (watch glass) to produce differential drying; migration is evaluated by comparing covered and uncovered areas.
- Two procedures
- Procedure A: Dry at room temperature (simple, time‑consuming - overnight).
- Procedure B: Dry in oven/dryer at (100 ± 2) °C until dry (about 7 minutes), using a pin frame and sandwiching watch glasses.
- Apparatus & materials: laboratory padder, watch glasses, glass plate or pin frame, dryer/oven, balance, spectrophotometer, grey scale (ISO 105‑A02). Preferred substrates are indicated (e.g., 65:35 polyester:cotton for disperse/vat/pigment, 100% cotton for reactive dyes) but any relevant production substrate may be used.
- Evaluation methods
- Visual: Use ISO 105‑A02 grey scale to rate migration 5 (no migration) to 1 (very severe migration).
- Reflectance: Measure reflectance at wavelength of maximum absorption on the uncovered area, calculate K/S (Kubelka–Munk), then compute percent migration with the provided formula.
- Reporting: Include reference to ISO 105‑Z06, pad liquor composition and concentrations, substrate and wet pickup, drying conditions, evaluation method and results, and any deviations.
Applications and users
- Useful for textile mills, dye houses, chemical suppliers, and quality control laboratories to:
- Compare migration behavior of dyes and pigments.
- Evaluate effectiveness of migration inhibitors, thickeners and electrolytes.
- Pre‑screen pad liquor formulations before continuous dyeing runs.
- Investigate and control shade variation or cross‑contamination on dye ranges.
- Relevant to product development, process optimization and troubleshooting in continuous textile dyeing.
Related standards
- ISO 105‑A02:1993 - Grey scale for assessing change in colour (normative reference).
- Part of the ISO 105 series covering tests for colour fastness; published under EN ISO 105‑Z06:2000 in the CEN system.
Keywords: EN ISO 105-Z06:2000, colour fastness, dye migration, pigment migration, pad liquor, migration inhibitor, grey scale, reflectance measurement, K/S, textile testing.