Features of environmental protection direct dye:
Environmental direct dyestuff is a kind of environment-friendly direct dyestuff used for polyester-cotton (polyester-viscose) fabric, polyester-cotton and polyester-viscose blended fabric with different properties of fiber in the same bath, which requires the direct dyestuff to have excellent high temperature stability, good lift and reproducing ability, good fastness and environmental performance.
Environmental protection direct dye operation process:
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Color paste and water treatment
the dye first with warm water (soft water) into a slurry, and then add the right amount of pure lye, and then heating, while constantly stirring, to the basic dissolution of the dye can be used.Direct dyes are not resistant to hard water and most can combine with calcium or magnesium salts to form an insoluble precipitate. Therefore, soft water dyeing is necessary.If hard water is used, it is softened with soda soda or sodium hexametaphosphate before it is used for dyeing.
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Add auxiliary dye
When willow products are dyed with direct dye, adding proper amount of salt or sodium sulfate in dyeing bath can promote dyeing and even dyeing.However, it has been proved in practice that the use of sodium sulfate as dye-promoting agent can get a brighter color while the effect of salt is poor, which is related to the purity of salt.
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Dyeing time
Dyeing time of willow products with direct dyes should be based on the characteristics of different dyeing rates of dyes.The time required for one stain is between 3 and 8 minutes.(for dyed finishing paint products only)
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Dyeing temperature
Dyeing temperature can be based on the type of dye properties to depend on the level, generally between 80-98oC.Moderate temperature can obtain good evenness and good color light and fastness.If the dyes with high dyeing rate and good levelness are used, the dye-loading rate is higher even at lower temperatures.The high temperature causes the dye rate to decline directly frozen yellow G, direct light yellow SG, direct blue G, these dyes wash fastness is also poor, only suitable for dyeing light color, and the temperature should be controlled between 85-90oC.For another example, direct yellow brown D3G, direct dark brown M and other dyes have low dyeing rate and poor evenness, and their dye-promoting effect is not obvious with the addition of dye AIDS. However, the temperature has a great influence on them.This kind of dye dyeing temperature must be controlled above 95oC, otherwise it will produce uneven color phenomenon, but the temperature can not be too high, to prevent the dye hydrolysis and failure.
