Powder coating is a type of coating that is applied as a free-flowing, dry powder. The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a “skin”. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminum extrusions, drum hardware and automobile and bicycle parts. Newer technologies allow other materials, such as MDF (medium-density fibreboard), to be powder coated using different methods When a thermoset powder is exposed to elevated temperature, it begins to melt, flows out, and then chemically reacts to form a higher molecular weight polymer in a network-like structure. This cure process, called crosslinking, requires a certain temperature for a certain length of time in order to reach full cure and establish the full film properties for which the material was designed. Normally the powders cure at 200 °C (390 °F) for 20 minutes. The curing schedule could vary according to the manufacturer’s specifications. The application of energy to the product to be cured can be accomplished by convection cure ovens, infrared cure ovens, or by laser curing process. The latter demonstrates significant reduction of curing time.
The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a “skin”.Most are centered around chipping and rusting. Powder Coatings resist cracking, peeling, and chipping. Powder coat is abrasion, corrosion and chemical resistant. This does not mean that it will not crack, peel, chip, scratch, or corrode.
ADVANTAGES OF POWDER COATING
- Powder coatings contain no solvents and release little or no amount of Volatile Organic Compounds (VOC) into the atmosphere. Thus, there is no longer a need for finishers to buy costly pollution control equipment.
- Powder coatings can produce much thicker coatings than conventional liquid coatings without running or sagging.
- Powder coated items generally have fewer appearance differences between horizontally coated surfaces and vertically coated surfaces than liquid coated items.
- The wide range of speciality effects are easily accomplished using powder coatings that would be impossible to achieve with other coating processes.
- Curing time is significantly faster with powder coating as compared to liquid coating.
According to a market report prepared in August 2016 by Grand View Research, Inc., the global powder coatings market is expected to reach USD 16.55 billion by 2024. Increasing use of powder coatings for aluminum extrusion used in windows, doorframes, building facades, kitchen, bathroom and electrical fixtures will fuel industry expansion. Rising construction spending in various countries including China, the U.S., Mexico, Qatar, UAE, India, Vietnam, and Singapore will fuel growth over the forecast period. Increasing government support for eco-friendly and economical products will stimulate demand over the forecast period. General industries were the prominent application segment and accounted for 20.7% of the global volume in 2015….