ISO 20705:2019

This document specifies common methods for the quantitative microscopical analysis of various mixtures of fibres. The methods described are based on the use of a light microscope (LM) or a scanning electronic microscope (SEM), on the measurements of the fibre apparent diameter (preparation of longitudinal views) or on the measurements of fibre section area (preparation of cross views), depending on the section shape of the fibres.

NOTE 1 When the section shape is circular or almost circular, the longitudinal views are appropriate. For the other section shapes, the cross views are adequate and Annex A lists conventional density of fibres to be used for the calculation of the mass percentage of the components. Pictures of section shapes of fibres can be found in ISO/TR 11827.

NOTE 2 Annex B presents statistical data on fibre diameter measurements (longitudinal view) and on fibre area measurements (cross view).

The given procedures apply to fibres in any textile form when mixtures of fibres cannot be separated by manual methods or by chemical methods.

Examples of mixtures of fibres are cashmere and wool, cotton and flax, flax and hemp.