Overview
EN ISO 105‑E12:2010 - "Textiles - Tests for colour fastness - Part E12: Colour fastness to milling: Alkaline milling" is a CEN-endorsed ISO method for assessing how well wool and part‑wool textiles retain colour when subjected to alkaline milling conditions. The standard defines two procedures: a severe (alkaline) method using soap plus sodium carbonate and a mild (soap-only) method applicable to light- or medium-weight wool clothing fabrics.
Key topics and technical requirements
- Scope: Resistance of wool/part-wool colours to soap + Na2CO3 (severe) or soap only (mild).
- Test principle: Composite specimens (test fabric + adjacent fabric(s)) are milled with steel balls in a rotating container filled with defined milling solution; afterwards colour change and staining are assessed.
- Apparatus:
- Rotatable water‑bath device with radial containers (≈ 75 mm diameter, 125 mm height, ~550 ml capacity).
- Non‑corrodible stainless‑steel balls (~6 mm dia.).
- Temperature control at (40 ± 2) °C and rotation frequency (40 ± 2) min‑1.
- Spectrophotometer or colorimeter for instrumental assessment (optional).
- Reagents and formulations:
- Milling solution A (severe): 50 g soap + 10 g anhydrous sodium carbonate per litre.
- Milling solution B (mild): 10 g soap per litre.
- Soap specification: limits on free alkali, total fatty matter, iodine value; free from fluorescent whitening agents.
- Grade 3 water (ISO 3696).
- Specimen preparation:
- Composite specimens (40 × 100 mm) made with multifibre adjacent fabric or two single‑fibre adjacent fabrics (as specified in Table 1).
- Test control for severe method: CI Acid Blue 7 dyed wool sample processed alongside specimens to validate test severity.
- Assessment:
- Use ISO grey scales for change in colour and staining (ISO 105‑A02 / A03) or instrumental evaluation (ISO 105‑A04 / A05).
- Mandatory control check: test-control must show specified change (rating 3) for valid severe method run.
Practical applications and users
- Quality control and R&D in wool textile manufacture and finishing.
- Textile testing laboratories verifying dye fastness for garments, upholstery and blended wool products.
- Dye houses and mills validating dyeing processes and finishing treatments (alkaline milling/fulled effects).
- Compliance evaluation for product specifications and trade performance claims.
Related standards
- ISO 105 series (general principles and assessment methods): ISO 105‑A01, A02, A03, A04, A05.
- Adjacent fabric specifications: ISO 105‑F01 … F10 (wool, cotton, viscose, polyamide, polyester, acrylic, multifibre).
- Water quality: ISO 3696.
By following EN ISO 105‑E12:2010, organisations can reliably measure colour fastness to alkaline milling, compare results across labs, and ensure wool products meet expected performance under milling/finishing conditions.