There are many processes in textile printing and dyeing, such as dyeing, printing, oiling and so on. Foam is produced in the printing and dyeing process, especially in the case of intense agitation such as high temperature and high pressure jet overflow dyeing. The appearance of foam is easy to cause fabric floating and uneven dyeing, so the use of defoamer is particularly important.






During textile processing. Defoamer can be used in all processes. When weaving and finishing, weaving and sizing Ordinary fabrics require sizing. According to the different fiber varieties, the main slurry are starch, carboxymethyl cellulose, methyl cellulose polyvinyl alcohol, polyvinyl acetate, acrylic ester and sodium alginate. These polymer substances are easy to produce foam in the slurry, affecting the penetration and making the slurry uneven. In weaving and sizing, low foam or no foam is needed, and there are many defoamer, especially acrylic synthetic chemical pastes for chemical fibers and silk, which contain emulsifiers and are easy to foam.




The characteristics of defoamer are:


1, fast defoaming speed, good foam suppression performance.


2, does not affect the basic performance of the foaming system.


3, high diffusion rate, good permeability.


4, chemical stability.


5. No physiological activity, no corrosion, no toxicity, no adverse side effects, no combustion, no explosion, high safety.


The defoamer used in textile printing and dyeing has two properties: bubble breaking and bubble suppressing. Some defoamants can only temporarily break the foam and lose their function after they dissolve into a liquid. The ideal defoamer requires both defoaming effect and defoaming effect. It has low solubility in water and is not easy to be emulsified and dissolved by the working liquid.




When the defoamer is added to the working solution, it becomes a solution, emulsion or dispersion, which is adsorbed on the surface of the foam film. Because its surface tension is lower than that of bubble film, it can attract surfactants or foaming materials to pull down the surface viscosity of the foam liquid film, and locally thin and crack. In general, textile printing and dyeing defoamer can be divided into organic defoamer and polysiloxane defoamer (commonly known as silicone defoamer). Organic defoamer - a liquid with low surface tension that is insoluble in water. The concentration of this defoamer is relatively large, about 0.1-0.4%, and the defoamer effect is often not lasting.




Polysiloxane defoamer - polydimethicone is composed of molecular weight; In addition to the above six advantages, when the solution content is 1-60p pm, the low concentration of these defoamer is another feature that can play a good and long-lasting defoamer effect, so it is particularly suitable for the high temperature, high pressure jet overflow dyeing industry, dyeing under high temperature and intense agitation.




Silicone defoamer with polysiloxane as the main raw material: pure silicone oil, silicone oil solution, silicone oil slurry, silicone oil emulsion, powder, bulk six kinds. According to the dosage form, defoamer can be divided into: solution, latex, powder, paste, block. Defoamer can be divided into: food, pharmaceutical, fermentation, paper making, printing and dyeing auxilaries, petroleum mining, storage and transportation, refining, lubricating oil, chemical production, metal cutting fluid, chemical cleaning, water treatment, etc. According to the emphasis on performance, defoamer can be divided into defoamer, defoamer and defoamer. Silicon defoamer and non-silicon defoamer are used in different processes in the textile printing and dyeing industry. Silica defoamer is an important development direction of textile dyeing and finishing additives. It has the characteristics of strong defoamer, long bubble inhibition, small dosage, stable chemical properties, high temperature resistance, non-toxic and non-toxic. In textile dyeing and finishing processing, the commonly used defoamer is the emulsion containing 1% ~ 2% polysiloxane.