When latex is stirred, poured, flowed and filtered, a large amount of foam is often generated due to air mixing. Due to the needs of the production process, the diluent used in the latex paint is water, and a certain amount of emulsifier must be used during emulsion polymerization to achieve Prepare a stable aqueous dispersion. Due to the use of emulsifiers, the surface tension of the emulsion system is greatly reduced, which is the main reason for foaming.
The pigment wetting agent and pigment dispersant in latex paint can also reduce the surface tension of the system, and promote the generation and stability of foam; when the viscosity of latex paint is low, it is not conducive to construction, and the use of thickeners will increase the thickness of the foam film wall Increase its elasticity, make the foam stable and not easy to eliminate; extract free monomers when producing emulsion: high-speed dispersion and stirring used in the preparation of latex paint; during the construction process, operations such as roller, brushing, spraying, etc. All these processes change the free energy of the system to different degrees, which helps to generate bubbles.
(Rubber industry)
Due to the foam problem of the latex liquid, the production operation is difficult. The air in the foam will hinder the dispersion of pigments or fillers, and also make the equipment utilization insufficient and affect the output. When the finished product is canned, more cans are required due to foam. During construction, air bubbles are left in the paint film and the surface is not smooth, which is unsightly and affects the service life of the paint film. The foam is not easy to dissipate in the latex, which makes further adding operations difficult. In addition, the mixing of air bubbles during molding, especially during dipping, often results in defective products or waste products. In order to eliminate these harmful factors, it is necessary to add rubber defoamers, emulsion defoamers, etc. to prevent the generation of bubbles or make the generated bubbles escape quickly.
The foam formed inside the aerosol container needs to be controlled, otherwise, unfavorable conditions will occur. First, when the container is shaken to disperse the propellant, the foam will reduce the efficiency of the shaking; second, when most of the volume of the aerosol container is used, foam formation will reduce the effective spraying of a large amount of liquid concentrate. When the internal foam is formed, the volume fraction of 10%-15% behind the container is filled with foam when shaken, and the propellant flows away when the useful components are not completely dispersed.
(Rubber defoamer)
The defoamer for rubber is a rubber defoamer specially designed for the foaming characteristics of the synthetic rubber industry. A mineral oil-based high-efficiency defoamer refined with a variety of defoaming active substances through a special process. The product does not contain silicone ingredients and is safe for synthetic rubber and its derivative products. The product has stable chemical properties, acid and alkali resistance, non-volatile, and non-toxic. It is used in the suppression of latex polystyrene butadiene rubber foam; it is also widely used in the defoaming of synthetic fibers and latex degassing systems. How to use: Stir properly before use, and it can be added directly to the foaming liquid.
