Over the past 30 years, powder coatings have brought revolutionary changes to the coating industry due to their excellent performance, good durability and environmental protection. These characteristics are particularly obvious in the field of metal products, such as electrical appliances, auto parts, and sports. Supplies and other metal products.
In recent years, advances in raw materials, construction processes, and curing methods have brought the possibility of applying powder coatings to heat-sensitive substrates. Powder coatings have now been applied to areas that were considered impossible a few years ago.
One of the major breakthroughs is in the application of medium density fiberboard (MDF). MDF is a kind of artificial board made by mechanical separation and chemical treatment of wood or plant fibers, mixed with adhesives and waterproofing agents, and then formed by high temperature and high pressure. Due to its low porosity and uniform surface characteristics, MDF It is a very suitable substrate for powder coating. MDF products include office furniture, kitchen and bathroom cabinets, doors, lockers and display racks, barbecue trays and assembled furniture.
Powder coatings are a revolutionary change for the MDF market. Not only do they have design freedom that cannot be provided by other coating methods, but powder coatings can provide colorful, beautiful, durable, and dense coatings. At the same time, powder coatings can also make MDF free It is troubled by crushing and sticking stains, water stains and scratches.
Challenges for thermal substrates
Some wood and wood products, because they contain a certain amount of moisture, can conduct electricity and can be painted directly. Compressed air can be used to remove surface contaminants on wooden parts that need to be polished. In order to enhance the adsorption capacity of the surface, the conductive liquid can be pretreated to provide a conductive surface. Then these wood products need to be preheated to a set temperature to help the powder coating adhere to the surface. A uniform surface temperature will help the efficiency of powder coating and the stability of the product coating. Next, use a spray gun to spray the charged powder coating onto the MDF surface. The main application of MDF is thermal curing powder coating or UV curing powder coating.
Thermosetting powder coatings rely on infrared heating, convection heating, or a combination of the two. The heat can make the powder coating melt and level, and further crosslink and solidify to form a coating.
For specially formulated UV-curing powder coatings, melting and leveling are separated from the curing process, and only a small amount of thermal energy is needed to complete the curing process. The substrate is first heated by infrared or convection for 2 to 10 minutes to melt and level the coating, and then the substrate is placed in ultraviolet light, and the curing of the coating can be completed in only a few seconds. Then, the substrate can be cooled naturally or artificially to complete the coating and leave the coating line.
Powder coating meets MDF product demand
Many office furniture manufacturers are abandoning standard shapes (such as rectangles, squares, etc.) and choosing more rounded corners to enable better placement of computer cables, etc. In addition, manufacturers also achieve various colors and effects through surface coating.
Powder coatings can fulfill these requirements well, while other surface treatment methods, such as welting methods, cannot fully meet the relevant requirements. In addition, powder coating can be completed in one step, without the need for multiple coatings or longer drying time.
