Calibrating Optical Laser Instruments for Fine Cashmere Fiber Testing
Precise optical calibration against certified wool and cashmere standards prevents costly diameter drift, securing accurate micron declarations and customs tariffs.
ISO 13735
Measurement Standard
International guidelines for evaluating yarn quality specify optical methods to quantify the number of protruding fibres along a yarn body. Compliance with iso 13735 ensures that yarn hairiness is measured uniformly across different manufacturing facilities and commercial testing laboratories. This standard defines the parameters for optical sensors that register the frequency and length of surface hairiness.
These measurements provide a common basis for comparing yarn performance before knitting or weaving.
Sensor Technology
Photoelectric detectors measure yarn hairiness by registering the interruption of light beams by protruding fibre ends. Operating under iso 13735, the testing apparatus feeds the yarn at a controlled speed through the measurement field. The sensor counts fibres that exceed specific threshold distances from the core of the yarn.
Highly hairless yarn reduces friction during weaving.
Specimen Preparation
Conditioning packages of yarn in a standard atmosphere of sixty-five percent relative humidity and twenty degrees Celsius is necessary before running the test. The mechanical tension applied to the yarn during unwinding must be carefully regulated to prevent artificial increases in surface hairiness, which would invalidate the results under iso 13735. This tension control prevents stretching and retains the true yarn structure.
Quality Control
Spinners use the test data to monitor spindle wear and ring travel performance on the spinning frame. A sudden increase in the hairiness value obtained via iso 13735 indicates a need for maintenance.