Many manufactured articles, whether they be of metal, plastic or glass, require a protective coat that also enhance their performance and appearance. Traditionally this has been done by giving them a coat or two of paint. Powder coating is a finishing process that applies plastic powder that is thermoplastic or thermosetting and done electrostatically so that the products have an even coating. If you need help, visit powder coating in Melbourne.
Powder coating has many advantages over liquid paint coatings and is cost-effective. The environmentally-friendly process gives high durability and long-lasting finish. It can be applied in a variety of colour and textures. Its environmental advantage comes from the fact that it contains no solvents. The parts coated have a high resistance to scratches, chipping, and fading. Colours remain brighter for a long time. The process of powder coating is challenging, with larger parts requiring more time for drying and curing. As heat is used, the materials on which the coating is to be applied can withstand the heat. It does require equipment that can be quite capital intensive.
The process of powder coating has to go through three stages, starting with the preparation, then the application, and followed by the curing. Click Doogood, for more information.
Preparation work is important as it ensures that the material coated has a surface that is suitable for coating. It can be done by immersing the material to be coated in dip tanks filled with weak alkali or detergent tanks, or spraying them with hot water or steam so that the oils, solvents and other residues that adhere to the substrate material are removed and the surface becomes completely clean. Where this substrate material has rust, scaling, or existing paint, blasting with pressurized fluid or other abrasive material, like sand git or shot, is the process used to achieve a clean and smooth surface. At times, during this preparation stage of the powder coating process, it may be needed to keep certain parts of the surface free of the coating, and certain masking products are used to achieve this and cover the areas that are not to be coated.
The second step of the application of the powder coat can be done in two ways. On most metal parts, the process used is electrostatic spray deposition and this electrostatic spray, gun deposits charged powder particles on the metal part. This work is carried out in powder spray booths while the powder is fed into the spray gun with a powder feeder. The part to be coated is positively charged so that it attracts the powder and allows it to bond to the charged surface. The second method is called a fluidized bed powder coating. In this process, the parts to be coated are preheated and then dipped into the powder material that is within a fluidized bed, over which there is a cloud of electrically charged powder particles. The system will have a tank to hold the powder, a means of charging the powder, and air supply at low pressure. The air helps to suspend the charged particles into which the parts to be coated are dipped. It allows coatings of a greater thickness.
Powders used for powder coating can be a thermoplastic or thermoset polymers. Both of these powders need to be heat cured, but it is done in different ways. Thermoplastic powder applied to workpieces that are heated. The heat causes the powder to melt, flow, and harden on cooling. It does not cause any chemical change in the powder. Thermoset powders can be applied at room temperature and then cured by heat in an oven. The powders used in this coating process come in many colours and rated for interior or exterior use. Studies show why powder coating is important.
The final process of powder coating is the curing. It keeps the already coated parts at temperatures between 160 and 200 degrees Celsius for a set period. It allows the polymers coated to undergo a chemical change that cures them to a hard shell.
Powder coating is a dry painting process that does not involve any volatile organic compounds as paints will do, and it is safer to use and better for the environment.