The discolored results of numerous machine washings and the Early fading of manufacturing textiles are signs of a lack of quality. This is the reason colour fastness tests are gaining global meaning. There are a quantity of evaluation methods systematically employed for color fastness and for dyes. The more important are:
- Grey Scale for Assessing Change in Colour: This Grey Scale is for analyzing changes in color of leather in color fastness tests, by way of instance, wash fastness, perspiration fastness, etc.. The scale consists of nine pairs of gray color chips representing a visual difference and comparison.
- Grey Scale for Assessing Staining: This Grey Scale is for analyzing the level of staining brought on by a dyed leather in color fastness tests. By way of instance, the staining of cotton and wool fabrics in the wash fastness, perspiration fastness, etc.. The scale consists of nine pairs of gray color chips each representing a visual difference and comparison.
- Colour Fastness of Leather to Light: This system is intended for determining the resistance of the color of leather into the action of a conventional artificial light source. The Xenon lamp has an emission wavelength profile near daylight. The side to be tested of the leather sample is exposed to light from a Xenon Lamp, under controlled conditions, along with eight blue dyed wool criteria (blue scale). The light fastness is assessed by comparing the fading of the leather with the fading of the grim criteria. The fading is typically made in two exposure times to better help the test.
- Colour Fastness of Leather to Mild Washing: Fastness of the color of leather to hand washing is your resistance to washing under gentle national laundering in water. In washing , not only varies in color can
Occur in the leather, but colored materials may bleed from it and can stain adjacent cloth materials.
- Colour Fastness of Leather to Machine Washing: Fastness of the color of leather to machine washing is your resistance to washing under national machine laundering in water. In washing leather, not only varies in color can occur in the leather, but colored substances may bleed out of it and can stain adjacent cloth materials.
- Colour Fastness of Small Samples to Dry Cleaning Solutions: This procedure is intended only for determining the resistance of the colour and the end of leather to dry cleaning solutions. It doesn’t pay for the suitability of composites or complete leather clothing to dry cleaning procedures.
- Colour Fastness of Leather to Migration to Plasticized PVC: The color fastness in respect of migration to plasticised poly(vinyl chloride) – PVC – is the transfer of color from leather to white plasticised PVC in 50 C. The side of the leather sample to be analyzed is placed on a white pigmented sheet of
Plasticised PVC along with the composite specimen is subjected to heat under pressure at an proper device for16 h at 50 C.
- Colour Fastness of Leather to Perspiration: From fastness of color of leather to sweat is intended its immunity to the prolonged action of an artificial sweat solution.
Another style of evaluation is Chrome-free leather. This leather has slowly gained commercial importance, especially for auto upholstery applications. In many respects, however, chrome-free leather is poor to chrome-tanned leather. UV and heat are known to be more detrimental to chrome-free leather compared to chrome-tanned leather, particularly in respect to the colorfastness of dyestuff and mechanical properties. Temperature, UV radiation, and humidity are key environmental factors that impact leather properties. The function of humidity and its interaction with UV radiation and temperature on leather possessions, however, aren’t clear to the leather business, and this advice is required for formulation of antioxidants which will protect chrome-free leather from UV and heat damage.