Types of Powder Coatings

Although there are not many varieties of powder coatings, there are also many polymer resins used as powder coatings. It can be basically divided into two categories: thermosetting and thermoplastic.

1. Thermosetting powder coating refers to a hard coating made of thermosetting resin as the film-forming substance, which can form an insoluble and non melting texture after adding a curing agent that triggers cross-linking reaction and heating. Due to the low polymerization degree and molecular weight of the resin used in thermosetting powder coatings, the coating has good leveling and decorative properties. Moreover, the low molecular weight prepolymer can form a network of cross-linked macromolecules after curing, resulting in good corrosion resistance and mechanical properties of the coating. Therefore, the development of thermosetting powder coatings is particularly rapid.

2. Thermoplastic powder coating. It melts at the spraying temperature and solidifies into a film when cooled. Due to the simple processing and spraying methods, powder coatings only require heating, melting, leveling, cooling, or extraction solidification to form a film, without the need for complex curing equipment. Most of the raw materials used are common polymers in the market, which can meet the performance requirements under most conditions. But there are also some shortcomings, such as high melting temperature, low coloring level, and poor adhesion to metal surfaces.

3. Fluororesin powder coating. There are many types of fluorinated polymers that can be used to prepare powder coatings, with excellent corrosion resistance, even in aqua regia, excellent dielectric properties, extremely low friction coefficient, and self-lubricating properties. Therefore, they are known as the "plastic king". Widely used in petroleum and chemical anti-corrosion coatings, sealing, bearing lubrication materials, electronic and electrical materials, ship launching guides, and non stick pot coatings.

4. Chlorinated polyether powder coating. Chlorinated polyether has excellent chemical stability, and its coating has good corrosion and dissolution resistance to various acids, bases, and solvents. Its chemical stability is second only to polytetrafluoroethylene, and its mechanical and friction properties are also very good. Chlorinated polyether powder coating is mainly used in chemical equipment, pipeline lining, instrument equipment shell, etc. Its disadvantage is poor adhesion to metals. Adding additives can improve the adhesion with metals and so on. There are other classifications as well. I will introduce it to everyone later.

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