Thermoplastic powder coating powder appeared in 1950. It melts at spraying temperature and solidifies into film when cooled.
Due to the simple processing and spraying method, the powder coating powder only needs heating melting, leveling, cooling or extraction solidification into film, no complex curing device is needed.
Most of the raw materials used are common polymers on 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, poor adhesion to the metal surface.
However, the commonly used thermoplastic powder coating powders still show some unique properties, among which polyolefin powder coating powders have excellent solvent resistance; polyvinylidene fluoride coating has outstanding weather resistance; polyamide has excellent wear resistance; polyvinyl chloride has a better price/performance ratio; thermoplastic polyester powder coating powder has the advantages of beautiful appearance and high artistry.
These characteristics make thermoplastic powder coating powder occupy a large proportion in the coating market.
2.1 Polyvinyl chloride powder is one of the cheapest polymers commercially produced on a large scale.
It has excellent solvent resistance, good corrosion resistance to water and acid, impact resistance, salt spray resistance, can prevent food contamination and electrostatic spraying has high insulation strength.
Mainly used for coating metal mesh, steel furniture, chemical equipment and so on.
2.2 Polyethylene powder coating has excellent corrosion resistance, chemical resistance, excellent electrical insulation and ultraviolet radiation resistance.
The disadvantage is that the mechanical strength is not high and the adhesion to the matrix is poor.
It can be used for chemical tanks, impeller, pump, pipe inner wall, instrument shell, metal sheet, refrigerator screen, auto parts and so on.
2.3 Nylon powder coating powder.
Nylon, also known as polyamide, usually has a higher melting point because the N atom of the chlorine group on the molecular chain is easy to form hydrogen bonds with the hydrogen atom on the adjacent chain segment.
Nylon has the advantages of high mechanical strength, impact resistance, hardness, wear resistance and low friction coefficient, low dust absorption, etc., can be used for special requirements of parts.
For example, it is used for pump impeller, textile machinery parts, diesel engine starting piston parts, motor sail propeller impeller, automobile wheels, motorcycle support, agricultural machinery, construction and sports equipment, etc.
In addition, because of the resistance to nylon salt water and mold, bacteria inert, very suitable for manufacturing immersion in seawater or contact seawater coating, and nylon powder coating powder is non-toxic, tasteless, not by mold erosion, will not promote bacterial growth, very suitable for spraying parts of the food industry, drinking water pipes and food packaging.