ISO/TC 38/SC 23/WG 5 - Fibres - Natural proteins

This document specifies a method of test for determining the percentage of medullated wool fibres by means of the projection microscope. The method is applicable to woollen and worsted products, at all stages, from raw materials to yarn.

This document specifies the test method for determining the size of silk yarns in all types of package forms. It is applicable to various kinds of silk yarns. It is not applicable to spun silk yarns.

ISO 137:2015 specifies the procedure and the measurement conditions for the determination of the wool fibre diameter using a projection microscope. The method is suitable for wool fibres in any form and also for other fibres of reasonably circular cross-section. (In the case of dyed, bleached or finished fibres, the diameter might be different from that of fibres not subjected to such treatments. The estimates of fibre diameter obtained at the various stages of processing one lot of wool will not necessarily be the same.)

ISO 18596:2015 specifies a test method for a staple length of dehaired cashmere by a hand-arranging method. ISO 18596:2015 is also applicable to dehaired camel, dehaired yak, etc.

ISO 1136:2015 specifies a method for the determination of the mean diameter of wool fibres, using an apparatus which passes a current of air through a bundle of fibres. This International Standard is applicable to clean, unmedullated wool fibres dispersed in a uniform, open state. It provides a method particularly suitable for combed slivers. The dichloromethane extractable matter content of the specimen must not exceed 1,0 %. It is applicable to oil-combed slivers after cleaning with an organic solvent. The method described in this International Standard is less accurate for lambswool and for wool which is appreciably medullated (see Annex D) and heavily dyed wool.

ISO 3074:2014 specifies a method for determining the dichloromethane-soluble matter in combed wool sliver. Its use can be extended to wool in other forms. It should be recognized that extraction with dichloromethane under the prescribed conditions does not completely remove all the fatty material present in a sample of wool. A further amount, possibly material of similar character, will usually be extracted by the use of solvents that cause greater swelling of the wool fibres. The method is applicable only to 100 % wool products. It can give misleading results if applied to products in which fibres other than wool are present.

ISO 15625:2014 specifies a test method for defects and evenness of raw silk by capacitive and optical electronic testers. It is applicable to raw silk with the yarn size between 13,3 dtex and 76,7 dtex or 12 denier and 69 denier, whether in skein or on cone, soaked or unsoaked.

The air permeability test method is based on the Kozeny equation. Weighed fibres (test specimen) are introduced in a measuring chamber with known volume. Air is passed through this test specimen. A scale indicating variations in permeability of air may be calibrated in appropriate absolute units of rate of flow or pressure difference and a table or graph is provided for conversion of the observed reading into values of mean diameter of the measured wool fibres.

Projection on a screen of the magnified images of the profiles of wool fibre pieces and measurement of their width by means of a graduated scale. The operating technique assures a random sampling of the fibres to be measured. Suitable for wool fibres in any form and also for other fibres of reasonably circular cross-section.