Common knowledge of coating: "wet touch wet" spraying

Core tip: "wet touch wet" process originated from the coating of industrial baking paint From the original two spray one grind two bake (spray bake grind spray bake) to two spray one dry When is the best time to "touch"? The key is to make the solvent of the first wet film volatilize as much as possible under the environmental conditions at that time and within the appropriate interval between layers, so that the second paint film "touched" does not have pinholes, bubbles or sags during the curing 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: "wet touch wet" technology from the industrial paint coating From the original two spray one grind two bake (spray bake grind spray bake) to two spray one dry When is the best time to "touch"? The key is to allow the solvent of the first wet film to volatilize as much as possible under the environmental conditions at that time and within the appropriate interval between layers The second paint film "touched" shall be free of pinholes, bubbles and sags during the curing process The appropriate interval time between layers, depending on the weather, substrate, paint type, wet film thickness, is usually within a suitable period of time after surface drying If you want to "touch" well, the principle should be that "the bottom should be a little thinner, the top can be thicker" The most vulnerable operation is "the lower layer is too thick and the interval between layers is not enough" This is to be emphasized, because "to seek change, we need to be careful, but to be quick, we cannot achieve it." If it is "wet to dry" or "dry", it is generally necessary to lightly grind it to ensure the adhesion In addition, tests shall be conducted to prevent "wet" from biting up "dry" "Wet touch wet" process is usually applied to PU polyester primer and NC nitro primer A thick spray of PU and NC coating is easy to produce pinholes, bubbles, sagging and other phenomena In order to avoid this phenomenon, the first coat (usually one coat refers to two crosses) can be sprayed first When the first coat reaches surface dry, the crosslinking reaction of crosslinking curing Pu primer has been preliminary For the volatile NC primer, most of the solvent in the film has evaporated when the first film is dry The first paint film starts to cure initially, and then spray the second paint, because the first paint film is not fully cured For PU type two paint films, they participate in the cross-linking reaction, and for NC type two paint films, they penetrate each other No matter it is Pu or NC type, the two-layer paint film will be integrated, without interlayer grinding, and the adhesion is also very good, just like the one-time spraying paint film However, for PE paint, its own characteristic is that a thick spray does not produce pinholes and bubbles Therefore, PE paint generally does not use the "wet touch wet" spraying process, and usually PE primer is finished by a continuous spray Through the above analysis, for the "wet touch wet" spraying process, it is necessary to grasp the application flexibly according to the actual situation, so as to achieve good results in quality and economy 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,