5. Application of defoamer in printing and dyeing
Application of defoamer in textile industry
Printing and dyeing industry is one of the departments that use silicone oil to eliminate foam. The 8 main processes of textile processing, namely spinning, sizing, weaving, removing pulp, washing, dyeing, dyeing and finishing, there are 4 processes (sizing, wool washing, dyeing and finishing) requiring surfactants and other auxiliaries. For example, in the process of fabric printing, leveling and bleaching, penetrant is often added to the dyeing of thick and dense fabrics to improve the dyeing uniformity, while the penetrant is very easy to bubble and cause color stains, even waste products; for example, when nylon silk printing, it is also easy to produce "bubble edge" and affect product quality. If silicone oil emulsion defoamer or octanol are added separately as defoamer, it can solve the problem of foam, improve levelling effect and stability of color paste. It should be pointed out that in the process of dyeing and finishing, there are strict requirements for the quality of defoamers used. If the stability of defoamer is not good, there may be oil stains or oil spots on the fabric, so that the product is downshifted or called waste. For this reason, the properties of defoamer, bath formula, acid and alkali, finishing temperature and stirring condition should be carefully selected. For general fabrics, silicone oil emulsion defoamer is preferred, and polyester emulsion fabric is used for dyeing at high temperature (above 130 degrees), and self emulsifying modified silicone defoamer is used.
From: textile printing and dyeing