How to Fix Powder Coating Caking

There are two main categories of powder coatings: thermoplastic and thermoset. Thermoplastic powder coatings have poor film appearance (gloss and leveling) and poor adhesion to metals, so they are rarely used in the field of automotive painting. Thermosetting powder coatings are generally used in automotive coatings. Thermosetting powder coatings are The thermosetting synthetic resin is used as the film-forming material. During the drying process, the resin is first melted, and then cured into a flat and hard coating film after chemical cross-linking. When the powder is stored, there will be agglomeration, how to solve it?

1) In the production of polyester resin, select some alcohols or acids that can increase its glass transition temperature, or reduce the amount of alcohol that can lower the glass transition temperature of resin to increase the glass transition temperature of polyester resin.

2) Reduce the amount of low glass transition temperature polymers used in powder coating formulation design, such as leveling agents and brighteners, to ensure that the glass transition temperature of the powder coating system will not decrease.

3) In terms of production, the broken flakes from the steel belt should be fully cooled before entering the grinding process. When grinding, the feeding speed should be appropriately reduced, the amount of induced air should be increased, and the imported air should be equipped with cold air conditioners to control the grinding process. temperature. However, if the crushed flakes cannot be cooled down before grinding, the latter method will not play a very good role. Consider the method of forced cooling of the crushed flakes for low temperature treatment, which is more effective than installing air conditioners.