What Is Powder Coating Equipment?
It is a type of coating equipment that helps in applying powder. Powder coating equipment does not involve solvents in its processes. The coating is carried out electrostatically and is then passed under heat, allowing the powder to flow and form a “skin”. It may be a thermoset polymer or a thermoplastic. Generally, it is used to give a hard finish which is harder than the conventional point which was formerly used. The main purpose of using this equipment is for coating metals, such as bicycle parts, household appliances, aluminium extrusions and many more.
Few advantages of powder coating are mentioned below:
– Emission Of Volatile Organic Compounds Are Reduced By Coating The Metals
– It Produces Much Thicker Coating As Compared To Traditional Liquid Coating
– It Can Be Recycled, Facilitating 100% Reusability Of The Substance
– Produces Less Hazardous Waste As Compared To Traditional Use Of Liquid
– Lesser Operating Cost Than Liquid Lines
Process Of Powder Coating
The Powder Coating Equipment work in following basic processes:
– Part Preparation Or The Pre-Treatment
– The Powder Application
Processes And Equipment Of Part Preparation
Prior to the powder coating process removal of lubrication grease, metal oxides, mud, oil etc are essential. There are various chemical as well as mechanical methods of removing these substances from the metal surface. The method depends upon the performance requirement of the finished product. In spray application process, chemical pre-treatments involve the use of chromates and phosphates. Phosphating and chromating of the substrate occur in multiple stage. Bonding of the powder to the metal involves cleaning in the pre-treatment process. Sand Blasting is an another method of preparing the surface prior to coating. It is used to provide finishing, etching, surface texturing and preparation and degreasing for products made of wood, glass, or plastic. Different powder coating applications can require alternative methods of preparation such as abrasive blasting prior to coating. The online consumer market typically offers media blasting services coupled with their coating services at additional costs.
Commonly electrostatic gun or corona gun is used for applying the powder coating to metal objects. Here, lets discuss the working of electrostatic gun. Negative electric charge is imparted to the powder. The negatively charged powder is then sprayed towards the grounded object by mechanical or compressed air spraying equipment. It is then accelerated towards the workpiece by the powerful electrostatic charge. The object is then heated, and the powder melts into a uniform film, and is then cooled to form a hard coating. To achieve more uniform finish preheating could help but problems can also be created as runs caused by excess powder.
Tribo gun is the second type of gun which is used to spray powder on metal surfaces. The powder is first charged by triboelectric friction and these charged powder particles then adhere to the grounded substrate. It requires a different formulation of powder with respect to corona guns.
Fluidized bed method can also be used for Powder coating. At first the substrate is heated and then it is dipped into aerated powder-filled bed. Later the powder sticks and melts to the hot object. Most dishwasher racks are coated with this method of coating.