| The discolored results of numerous machine washings | | | | laundering in water. In washing leather, not only |
| and the Early fading of manufacturing textiles are | | | | changes in colour can occur in the leather, but coloured |
| indications of a lack of quality. This is why color | | | | substances may bleed from it and may stain adjacent |
| fastness tests are gaining international meaning. There | | | | textile materials. |
| are a quantity of test methods systematically used for | | | | - Colour Fastness of Small Samples to Dry Cleaning |
| colour fastness and for dyes. The more significant are: | | | | Solutions: This method is intended only for determining |
| - Grey Scale for Assessing Change in Colour: This | | | | the resistance of the colour and the finish of leather to |
| Grey Scale is for assessing changes in colour of | | | | dry cleaning solutions. It does not cover the suitability of |
| leather in colour fastness tests, for example, wash | | | | composites or complete leather garments to dry |
| fastness, perspiration fastness, etc. The scale consists | | | | cleaning processes. |
| of nine pairs of grey colour chips all representing a | | | | - Colour Fastness of Leather to Migration into |
| visual difference and contrast. | | | | Plasticized PVC: The colour fastness in respect of |
| - Grey Scale for Assessing Staining: This Grey Scale | | | | migration into plasticised poly(vinyl chloride) - PVC - is |
| is for assessing the degree of staining caused by a | | | | the transfer of colour from leather to white plasticised |
| dyed leather in colour fastness tests. For example, the | | | | PVC at 50 C. The side of the leather sample to be |
| staining of wool and cotton fabrics in the wash | | | | tested is placed on a white pigmented sheet of |
| fastness, perspiration fastness, etc. The scale consists | | | | Plasticised PVC and the composite specimen is |
| of nine pairs of grey colour chips each representing a | | | | exposed to heat under pressure in an appropriate |
| visual difference and contrast. | | | | apparatus for16 h at 50 C. |
| - Colour Fastness of Leather to Light: This method is | | | | - Colour Fastness of Leather to Perspiration: By |
| intended for determining the resistance of the colour of | | | | fastness of colour of leather to perspiration is meant |
| leather to the action of a standard artificial light source. | | | | its resistance to the prolonged action of an artificial |
| The Xenon lamp has an emission wavelength profile | | | | perspiration solution. |
| close to daylight. The side to be tested of the leather | | | | Another way of test is Chrome-free leather. This |
| sample is exposed to light from a Xenon Lamp, under | | | | leather has gradually gained commercial importance, |
| controlled conditions, along with eight blue dyed wool | | | | particularly for automobile upholstery applications. In |
| standards (blue scale). The light fastness is assessed | | | | many respects, however, chrome-free leather is |
| by comparing the fading of the leather with the fading | | | | inferior to chrome-tanned leather. UV and heat are |
| of the blue standards. The fading is typically made in 2 | | | | known to be more detrimental to chrome-free leather |
| exposure times to better assist the evaluation. | | | | than to chrome-tanned leather, especially in regard to |
| - Colour Fastness of Leather to Mild Washing: | | | | the colorfastness of dyestuff and mechanical |
| Fastness of the colour of leather to hand washing is | | | | properties. Temperature, UV radiation, and humidity are |
| the resistance to washing under mild domestic | | | | key environmental factors that affect leather |
| laundering in water. In washing leather, not only | | | | properties. The role of humidity and its interaction with |
| changes in colour can | | | | UV radiation and temperature on leather properties, |
| Occur in the leather, but coloured substances may | | | | however, are not clear to the leather industry, and this |
| bleed from it and may stain adjacent textile materials. | | | | information is needed for formulation of antioxidants |
| - Colour Fastness of Leather to Machine Washing: | | | | that will protect chrome-free leather from UV and heat |
| Fastness of the colour of leather to machine washing | | | | damage. |
| is the resistance to washing under domestic machine | | | | |