Paint knowledge | why does NC paint film turn white and how to prevent it?

Core tip: answer: the phenomenon that the paint film presents turbid or milky white after film forming is called film whitening, also called whitening, whitening, etc The reasons for the whitening of nitrolacquer film during spraying are as follows: 1 Nitrolacquer itself has very good solvent release property, and the solvent volatilizes to the atmosphere in NC paint, which is easier than in other paints; 2 NC paint formula contains more solvent with faster volatilization; 3 In case of high temperature environment, the solvent volatilizes faster; 4 The solvent evaporated rapidly, absorbed the internal energy of the wet film of NC paint film just sprayed, and made the surface temperature of the wet film drop 2-30c instantly, 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 Home of coatings: A: after the coating film appears turbid or milky white phenomenon is called film whitening, also called whitening, whitening, etc The reasons for the whitening of nitrolacquer film during spraying are as follows: 1 Nitrolacquer itself has very good solvent release property, and the solvent volatilizes to the atmosphere in NC paint, which is easier than in other paints; 2 NC paint formula contains more solvent with faster volatilization; 3 In case of high temperature environment, the solvent volatilizes faster; 4 The solvent volatilizes rapidly, absorbs the internal energy of the wet NC film just sprayed, makes the surface temperature of the wet film drop 2-30c instantly, and provides a "cooling bed" where "condensation" occurs; 5 The high temperature and high humidity environment makes the high content of water vapor around the wet film condense rapidly on the "cooling bed" to form micro water droplets; 6 The phenomenon of turbidity or milky white is caused by the bad miscibility of water droplets and wet film, which is called "whitening" The above 1, 2 and 3 are prerequisites for whitening, 4 is the intermediate process, and 6 is the final result After the occurrence of whitening phenomenon, some appropriate heating (such as lighting) can make the whitening disappear and recover as before Some of them are irreversible and white forever for unknown reasons Although there are estimates, they will not be repeated The following measures can be taken to prevent the paint film from "whitening": 1 The temperature of the painting environment should be 15-250c, and the relative humidity of the environment should not be more than 75%; 2 The effect of oil-water separator should be checked frequently during spraying, and the moisture in the compressed air should be removed in time; 3 The paint and Tianna water of higher quality should be taken as far as possible; 4 In the high temperature and high humidity environment, white water (such as nz308 white water of China Resources furniture paint) can be added when white phenomenon occurs during construction In fact, slow dry solvent can be added to reduce the evaporation speed of solvent on the surface of wet film and prevent the formation of "cold bed" When adding the white water, first add the white water into Tianna water and mix well, then add Tianna water into the paint normally The general adding amount is: Tianna water: white water = 9:1 (weight ratio) The maximum dosage can be increased to 20% of Tianna water In this case, if the paint film is still white, the coating shall be stopped, and the construction shall be carried out after the ambient temperature and humidity are reduced Because too much white water will make the film dry too slowly, soft and sticky, which will affect the quality of the film 5 Use the right method to keep the indoor painting environment in line with the requirements It's wrong to open doors and windows to "ventilate" when it's cloudy and rainy outside When it's cloudy and rainy outside, the humidity will drop, but the indoor humidity will still be wet, which will not dry for several days This is the result of the water vapor is easy to enter and hard to get out At this time, it's right to open the doors and windows, or even forced ventilation 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,