ISO 23733:2007

Overview

ISO 23733:2007 specifies a standardized test method for the determination of linear density of chenille yarns. The standard defines how to prepare, condition, reel and weigh skeins of chenille yarn to calculate yarn linear density expressed in the Tex system. It addresses the higher inherent variation of novelty chenille yarns and provides sampling guidance and reporting requirements to ensure reproducible, comparable test results.

Key topics and technical requirements

• Test principle: Linear density (tex) is calculated from the mass (grams) and length (metres) of conditioned skeins:
  Linear density (tex) = (m × 1000) / L, where m is mass in g and L is length in m.
• Skein length: Test skein length is 25 m.
• Reeling apparatus: Typical reel perimeter is 1 000 mm (±0.25% recommended). Reels must avoid bunching and indicate length wound; traversing mechanism and length checks required.
• Reeling tension: Reeling under specified tension - 0.5 cN/tex - to produce reproducible skein lengths; adjust tension until skein length tolerance is within ±0.25%.
• Weighing: Use a balance with sensitivity of 1 part in 1 000 (grams) for average linear density determination.
• Conditioning: Condition sample and test skeins to moisture equilibrium in standard atmospheres per ISO 139 (humidity/temperature control); deviations must be reported.
• Sampling & number of specimens: Sampling guidance is in Annex B. Default test count is three skeins per sample skein unless specified otherwise; statistical guidance and required specimen numbers are included for higher precision.
• Variation guidance: Table of industry variation tolerances is provided (e.g., for 1 skein ±20%, 5 skeins ±10%, 10 skeins ±6%, 25 skeins ±4%, 100 skeins ±2%).
• Reporting: Test report must reference ISO 23733:2007 and include sample ID, mean linear density (tex), number of specimens, skein length, sampling scheme, any coefficient of variation, and any procedural deviations.

Applications and practical value

• Ensures consistent measurement of chenille yarn fineness for quality control, specification compliance, incoming inspection and supplier verification.
• Supports production control in chenille yarn manufacturing and downstream textile processes (weaving, knitting, tufting) where yarn mass per length affects fabric weight, appearance and performance.
• Useful in procurement specifications, testing laboratories, research & development, and regulatory documentation to compare products and verify declared yarn counts.

Who should use this standard

• Chenille yarn manufacturers and their QC teams
• Textile testing laboratories and conformity assessment bodies
• Fabric manufacturers that consume chenille yarns
• Product specifiers and procurement specialists

Related standards

• ISO 139 - Standard atmospheres for conditioning and testing (normative reference)
• ISO 2060 - (referenced for comparison) yarn linear density methods for conventional yarns

Keywords: ISO 23733, chenille yarns, linear density, tex, test method, skein, reeling tension, textile testing, ISO 139.