UV curable powder coating
UV-curing powder coating is a new coating technology combining powder coating technology and UV curing technology. It combines the advantages of traditional powder coating and liquid UV-curing coating technology, and overcomes the shortcomings of two types of coatings to some extent.
Conventional thermal curing powder coatings require curing at 180-200 ° C for 5- to 30 minutes, which limits the application of this technology in heat sensitive substrates. The rapidly growing UV-curable powder coating with a melting point of 100 to 1200 °C solves this problem. Compared with traditional heat-cured powder coatings, the melt leveling and solidification of UV-cured powder coatings are two separate processes. The powder particles are first heated and melted by infrared radiation, and then cured by ultraviolet radiation. Smooth and smooth coating. Since the UV-curable powder coating has a low melting temperature, it can be widely used for coating of heat-sensitive substrates (such as paper, rubber, plastic), which greatly expands the application space of the powder coating. UV-curing powder coating has no reactive diluent, low shrinkage of coating film, high adhesion to substrate, and can form a thick coating with good quality (75-125 gm) in one coating, and the powder sprayed by paint can be recycled. Used, therefore, UV-curable liquid coatings have higher technical, economic and ecological advantages.
Foreign countries began to develop UV-cured powder coatings in the early 1990s. They were commercialized in the mid-1990s and developed rapidly. There are many reports and patents on UV-cured powder coatings for wood, metal, metal/composite parts, and paper substrates. UCB Chemicals of Belgium has developed the UvecoatTM series of powder coatings, of which the UvecoatTM 1000 series is suitable for composite woods; the Uvecoat TM2000 series is suitable for metal substrates. DSM reported the use of UV-cured powder coatings on paper substrates.