Common knowledge of coating: the coating contains bubbles and Degas badly. How to solve it?

Core tip: questions: In the production process of waterborne coatings, it is found that the coatings contain large and small bubbles after thickening The larger the bubble size is, the smaller the bubble size is The reversion phenomenon often occurs in the thick paste coating such as elastic roughening After the water-based coating film is dried, bubbles will cause pinholes or prickles, which will affect the appearance of the coating film Interpretation: The way to produce bubbles in water-based coatings: in the coating manufacturing process, the dispersion of pigments and fillers, the mixing in the thickening and paint mixing process, the vibration of the finished coating in the filtration and sub packaging process, the mixing and mixing of the coating and the color paste in the color mixing process Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Paint Home News: problem: in the production process of waterborne paint, it is found that the paint contains large and small bubbles after thickening The larger the bubble size is, the smaller the bubble size is The reversion phenomenon often occurs in the thick paste coating such as elastic roughening After the water-based coating film is dried, bubbles will cause pinholes or prickles, which will affect the appearance of the coating film Explanation: the way to produce bubbles in water-based coatings: in the coating manufacturing process, the dispersion of pigments and fillers, the mixing in the thickening and paint mixing process, the vibration of the finished coating in the filtration and subpackage process, the mixing and mixing of the coating and the color paste in the color mixing process, the mixing and introduction of air, the air in the water-based coating is wrapped by surfactant and stabilized in the coating to become bubbles As for the formulation and production process of water-based coating, the bubbles produced in the coating manufacturing process are mainly in the following processes 1 The improper feeding sequence of pigments and fillers in the dispersion stage can easily lead to the formation of tiny tip bubbles, especially in the coating system with high proportion of ultrafine fillers and high solid content The particle size of the fine particle is larger than the surface area The air adsorbed more should be put in low viscosity first, which is favorable for the foam to escape If the fine-grained filler is put into operation at the last stage, the viscosity of the slurry will be high after the fine-grained filler is put into operation, and a large amount of air brought in by the fine-grained filler will enter the slurry to form micro bubbles It is difficult for microbubbles to aggregate and grow up and rise to the surface of the coating to crack, which makes it difficult for all gases to escape from the coating 2 In the formulation of water-based coating, excessive surfactant is easy to bubble during mixing The vibration in the production, filtration and transportation of the coating, as well as the dumping and mixing of the coating from a high place, will once again produce bubbles that are difficult to get out 3 The design of the dispersing disc teeth of the dispersing machine is unreasonable, or the dispersing disc is improperly placed in the coating during the dispersing process Under high-speed mixing, a large amount of air is brought into the coating with high-speed dispersing by vortex Prevention and solution: 1 The feeding of water-based coating production should be in the order of first fine and then coarse, which is conducive to the bubble out and prevent the generation of micro bubbles; 2 The wetting agent should not be used excessively in the production of water-based coating formula, and it is not allowed to replace the dispersant with wetting agent If it is necessary to use in order to meet some requirements, low foam wetting agent should be selected Additional wetting agents are added during the paint mixing phase The defoamer with high antifoaming capacity is added to the slurry preparation; 3 The filtration, packaging and dumping of the coating should be carried out to reduce the vibration and dumping height as much as possible; 4 The dispersion disk should be selected properly, and the position of the best dispersion disk in the dispersion material should be determined through practice when dispersing the material, so as not to form a large vortex in the dispersion, so as not to bring in a large amount of air Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,