Different Colorfastness Test Standards In Different Countries

Due to the use of chemicals in the late processes of dyeing and finishing, like acid, alkali, oxidants, reductants, etc., and when using in washing, sunlight, rubbing, sweat, high temperature and so on, dyeing textiles may fade or discolor. Therefore, dye color fastness is diverse, including washing fastness, light fastness, rubbing fastness, perspiration fastness, chlorine fastness, ironing fastness, etc.   The color fastness requirement of textiles is different because of their different use and process. For example, the curtain which is less washed requires low colorfastness, but due to exposure to the sun for a long time, it needs high lightfastness. Summer clothing fabrics should have higher light fastness, washing fastness and perspiration fastness for the reason that they always expose to sun and human body always sweats.   Colour fastness is assessed generally by comparing any staining of specified adjacent fabrics during the test with a set of standard ‘grey scales’. A numerical grading is given on a scale of 1–5, where 1 is very poor and 5 is excellent. Generally, a grade of 4 or above is deemed acceptable for commercial use.   Different countries have set different standards for the different colorfastness requirements of different textiles. The main standards for colorfastness are as follows: 1. AATCC (American Association of Textile Chemists and Colorists) technical manual: Describes 66 numbers of different colorfastness tests. 2. SDC (Society of Dyers and Colorists): In 1927, SDC (Europe) made fastness test committee. 3. ISO(International Organization for Standardization): In 1947, ISO made color sub committee. ISO also grades the fastness: For light fastness: 1~8 For other fastness: 1~5