What Kind of Factors will Lead to Pigmentation on The Vat Dyed Fabrics?
2016-09-05 08:31 | writer: admin
Sometimes there will be some color stains or color spots on the vat dyed fabrics surface, mainly due to the following aspects:
1.The chemical raw material is not even enough: just like the painting pigment, if the temperature is low in winter, the pigment will gather easily and difficult to melt, So it is important to stir evenly under a certain temperature, it will be much better to filter the large particles and impurities.
2, Grey fabric issue: If there is no problem in dyeing, but the fabric has a problem, then will also cause the color stains. For example: the impurities left on the grey fabric will result in uneven dyeing. If the fabric itself has the color yarn, it is no use even though dyeing evenly. Especially the pH problem of cloth. The dosage of the caustic soda in pretreatment need to be carefully and accurately, too much or too little both will hurt the grey fabric. Some fabric were over-treated with caustic soda, its color may become deep. How much caustic soda will be based on specific fabrics.
3, The water for dying: Water is very important, The water quality and the metal ion amount has very big effect on the dying and printing, especially the iron ion.
4, The control of the dyeing heating rate: if the temperature increase too fast, it will also cause the pigmentation on the fabric.
5, The improper use of dyeing auxiliaries: The use of additives is not the more the better, the defined amount if very important. For example, some softening agents are not heat resistance, if used in high temperature, will cause the breaking of emulsion and gathered to form the oil color spots and uneven color lump inevitably. In addition, if the low temperature(no more than 40℃) silicone oil which was added in the vat dye or the cationic softener was not washed off, it will also affect the fabric color in the next vat.
6, The dye compatibility issues.
7, Poor quality dyes, some manufacturers blind pursuit the lower costs and use the dyes with poor dispersion forces, So the quality cannot be guaranteed.