Overview
ISO 18067:2015 - Textiles - Synthetic filament yarns - Determination of shrinkage in dry‑hot air (after treatment) specifies standardized methods to measure dry‑hot air shrinkage of synthetic filament yarns. It covers two principal test approaches: the skein method (manual and automatic measurement variants) and the single‑end method (manual measurement). The standard applies to synthetic filament yarns with nominal linear density less than 3 000 dtex and excludes partially oriented yarns. In disputes, the manual procedure is the reference method.
Key topics and requirements
- Test methods: Skein method A (manual), Skein method B (automatic), and Single‑end method (manual).
- Apparatus: specifications for skein winding reels, length‑measuring stands, automatic shrinkage testers (0.05 mm resolution), and a ventilated oven with controlled temperature (±3 °C) and internal height ≥ 600 mm.
- Specimen preparation: reeling procedure, knotting, and conditioning in a standard atmosphere (referenced ISO 139). Set skein linear densities (example table): ≤ 400 dtex → 2 500 dtex skein; > 400 to ~ 3 000 dtex → 10 000 dtex skein.
- Tension control: tension calculated from yarn linear density; typical tension per unit linear density: non‑textured yarns (0.05 ± 0.01 cN/dtex), textured yarns (0.20 ± 0.04 cN/dtex).
- Dry‑hot air treatment: temperature and time depend on fiber type (examples from the standard: polyester/polyamide 66 - 190 ± 3 °C, 15 ± 1 min; multifilament polyamide 6 - 170 ± 3 °C, 15 ± 1 min; polypropylene - 110 ± 3 °C, 15 ± 1 min).
- Sampling and number of specimens: requirements for lot and laboratory samples (minimums range from 10 to 20 specimens depending on lot size; arbitration procedures specify up to 60 specimens).
- Results: shrinkage expressed as percentage decrease in length before and after thermal treatment; procedures for measurement, equilibrium times, and reporting are specified.
Applications
- Quality control and acceptance testing for manufacturers and suppliers of synthetic filament yarns (polyester, polyamide, polypropylene).
- Textile testing laboratories verifying dimensional stability after heat treatment.
- Product development and R&D where yarn shrinkage affects downstream processes (texturizing, weaving, knitting, finishing).
- Procurement, compliance, and arbitration where standardized shrinkage data are required.
Related standards
- ISO 139 - Standard atmospheres for conditioning and testing (referenced for conditioning and moisture equilibrium).
Keywords: ISO 18067:2015, dry‑hot air shrinkage, synthetic filament yarns, skein method, single‑end method, textile testing, shrinkage test.