Overview
ISO 5688:2024 - Textiles - Synthetic filament yarns - Test methods for crimp properties of textured yarns defines standardized laboratory procedures to determine the crimp behaviour of synthetic textured filament yarns. The standard specifies two approved crimp-development treatments: Method A (hot air) and Method B (hot water), and describes specimen preparation, conditioning, measurement, calculation of results and reporting requirements.
Key topics and technical requirements
- Scope: Test method for crimp properties (contraction, modulus, stability) of textured synthetic filament yarns.
- Crimp development methods:
- Method A - Hot air: development of crimp using a ventilated oven (temperature range and stability requirements provided).
- Method B - Hot water: immersion in hot water (use distilled or grade 3 water with non‑ionic surfactant 0.1 g/L unless otherwise agreed).
- Specimen preparation:
- Skein winding reel with specified circumference (1 000 ± 2.5 mm), controlled tension and turn count.
- Tension for reeling calculated by FP = P × T, where P for textured yarns = (0.20 ± 0.02) cN/dtex.
- Recommended set linear densities for skeins (examples: ≤200 dtex → 2 500 dtex; 200–400 dtex → 5 000 dtex; >400 dtex → 10 000 dtex).
- Apparatus requirements:
- Test specimen holder (vertical frame, hooks/clamps, >600 mm height).
- Length measuring device accurate to ±0.1 mm and tension application devices avoiding >10% overshoot.
- Ventilated oven (30 °C–130 °C capability, temperature variation ±2 °C near specimens).
- Hot water container capable of maintaining 100 °C ±3 °C around specimens.
- Conditioning and sampling:
- Standard atmosphere per ISO 139.
- Sampling guidance: avoid testing earlier than 5 days after processing; stress‑decay effects largely negligible after 7 days.
- Results and calculations:
- Express crimp contraction, crimp modulus, and crimp stability according to the methods and formulas in the standard.
- Precision and reporting: includes precision data and required test report items.
Applications and users
ISO 5688:2024 is intended for:
- Textile testing laboratories performing routine quality control of textured filament yarns.
- Yarn and filament manufacturers validating crimp characteristics during product development and acceptance.
- R&D teams assessing process changes (texturising, heat setting) and performance effects.
- Conformance and certification bodies requiring harmonized test data for specification compliance.
Practical benefits include reproducible crimp measurements for product specification, quality acceptance, process optimisation, and comparative benchmarking across suppliers.
Related standards
- ISO 139 - Standard atmospheres for conditioning and testing (referenced for environmental control).
- ISO 10132 - Definitions for textured filament yarns.
- ISO 3696 - Water for analytical laboratory use (grade 3 water).
- ISO 3534‑1 - Statistical vocabulary related to test precision and reporting.