This part of ISO 105 specifies a method for determining the resistance of the colour of textiles of all kinds and in all forms to the action of dilute solutions of organic and mineral acids.
Three tests differing in severity are provided Any or all may be used, depending upon the nature of the fibre.
Drops of a solution of acid are placed on the specimen, the surface of which is rubbed gently with a glass rod to ensure penetration. The changes in colour of the textile, while it is still wet and after drying, are assessed with the grey scale. Three tests differing in severity are provided.
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