Overview
EN ISO 105‑X14:1997 (ISO 105‑X14:1994) specifies a laboratory test method to assess colour fastness of wool to acid chlorination using sodium dichloroisocyanurate. The procedure simulates a common manufacturing operation in which a mildly acidic liquid containing or liberating active chlorine is used to impart shrink‑resistant properties to wool. Change in colour after treatment is evaluated against the ISO grey scale.
Key topics and technical requirements
- Scope: Applies to wool textiles in all forms (yarn, fabric, garments, loose fibre after suitable preparation).
- Test chemistry:
- Use a formic acid buffer (pH 4.0 ± 0.2) containing sodium formate and a wetting agent.
- Sodium dichloroisocyanurate solution (11.27 g/L dihydrate - typical 55% available chlorine on mass basis) is added to introduce active chlorine.
- Sodium hydrogensulfite solution (3.29 g NaHSO3/L) is used to quench the reaction.
- Grade 3 water and starch‑iodide paper are specified for checks.
- Procedure essentials:
- Continuous agitation and full immersion are required, particularly after adding sodium dichloroisocyanurate.
- Dosages and liquor ratios specified per specimen mass (e.g., 47 mL buffer per g specimen; 3.0 mL dichloroisocyanurate solution per g; 10.0 mL NaHSO3 solution per g).
- Test temperature maintained at 25 °C ± 2 °C; rinsing sequence and a final drying step (60 °C ± 5 °C) are prescribed.
- Presence of residual available chlorine is checked with starch‑iodide paper; specimens failing the check are discarded and retested.
- Assessment: Colour change is assessed using the ISO grey scale (ISO 105‑A02). Optional separate staining tests for adjacent white wool are described.
Practical applications and users
- Textile manufacturers and wool processors use this standard to evaluate how dyeings will withstand acid chlorination steps used for shrink resistance.
- Quality assurance and independent textile testing laboratories rely on EN ISO 105‑X14 for reproducible, comparable colour‑fastness data.
- Dye houses, product developers, and procurement/specification engineers reference the method when qualifying dyes, finishes, or processing routes for wool products.
- Useful for compliance testing, process optimization, troubleshooting discolouration during production, and communicating requirements between suppliers and buyers.
Related standards
- ISO 105‑A01: General principles of colour fastness testing (referenced for conditioning, water quality, wetting).
- ISO 105‑A02: Grey scale for assessing change in colour (used for evaluation).
- ISO 3074: Determination of dichloromethane‑soluble matter in wool (relevant for specimen pre‑treatment limits).
Keywords: EN ISO 105‑X14:1997, colour fastness, acid chlorination, wool, sodium dichloroisocyanurate, textile testing, grey scale, shrink‑resistant wool.