Analysis of ISO 4913 Test Method for Cotton Fiber Length
ISO 4913 is an international standard method for determining the span length and uniformity index of raw and semi-processed cotton fibers. Based on optical scanning technology, this standard obtains continuous information on fiber length distribution through non-destructive measurement of processed cotton fiber bundles, thereby assessing the spinnability and processing stability of cotton fibers. Cotton fiber length is one of the important fundamental indicators determining yarn strength, evenness, and breakage rate, while the concentration of length distribution further affects the drafting stability and yarn structure consistency during spinning. Therefore, this standard is not only a testing method but also a key component of the textile raw material quality evaluation system. In actual testing, ISO 4913 emphasizes the measurement of “fiber group distribution characteristics” rather than the ideal length of a single fiber. This distinguishes it from traditional manual measurement me...