Overview
ISO 105-203:1996 - Textiles: Tests for colour fastness - Part Z03: Intercompatibility of basic dyes for acrylic fibres specifies a laboratory method to determine how a basic (cationic) dye behaves when mixed with other basic dyes on acrylic fibres. The standard clarifies whether a dye yields on‑tone, bluer or yellower dyeings across a set sequence of reference dyes, using defined test baths and visual assessment scales. It is part of the ISO 105 colour‑fastness series.
Key topics and requirements
- Scope: Evaluates compatibility of a basic dye with other basic dyes when applied to acrylic fibres under controlled dyeing conditions.
- Reference dye series: Two five‑step scales (yellow and blue) are used. Compatibility is reported as the value of the reference dye that produces on‑tone dyeings with the test dye.
- Test conditions:
- Liquor:goods ratio: 40:1
- pH: 4.5 ± 0.2 (acetate buffer)
- Pretreatment: approx. 95 °C for 10 min in 1% glacial acetic acid + 1% sodium acetate (omf)
- Dyeing temperature and time adjustable within 90–100 °C and 5–10 min to achieve approximately equal exhaustion across specimens
- Use grade 3 water (ISO 3696) and analytical‑grade reagents
- Specimens and procedure: 4–6 specimens per dyebath; five dyebaths prepared - one for each reference dye - containing specified amounts of reference dye and the dye under test to achieve about 1/2 of 1/1 standard depth.
- Assessment: Visual assessment across the sequence; compatibility value can be whole or half steps (e.g., 2.5). Values outside the scale are reported as less than 1 or greater than 5.
- Reporting: Include standard number/year, full description of dye and acrylic fibre used, and the observed compatibility value.
- Safety: Follow good laboratory practice, personal protective equipment, and local safety regulations.
Applications and users
- Dye and chemical manufacturers validating new basic dyes for acrylic fibre systems
- Textile mills and dyehouses performing quality control and batch formulation
- Colour‑matching and R&D laboratories assessing dye combinations to avoid unlevelness or hue shifts
- Procurement and compliance teams ensuring dyes meet compatibility requirements for blended shades
- Troubleshooting colorfastness and shade variation issues in acrylic garments and home textiles
Related standards
- ISO 105 series (general colour‑fastness testing principles)
- ISO 105‑A01: General principles of testing (referenced for context)
- ISO 3696:1987 Water for analytical laboratory use (water quality for testing)
Keywords: ISO 105-203:1996, colour fastness, compatibility testing, basic dyes, acrylic fibres, dyeing procedure, reference dyes, textile testing, laboratory method.