New horizons in wood finishing.
Manufacturers are continually seeking new technologies to help cut costs, increase productivity and enhance product quality. In recent years, manufacturers of finished metal products have relied on powder coatings to achieve such goals. Due to the economic and environmental benefits they provide, powder coatings have become one of the fastest growing segments of the finishing industry.
Powder coatings have primarily been used to finish metal products such as household appliances, file cabinets, barbecue grills, and lawn and garden furniture. Several obstacles have prevented this technology from expanding beyond applications on metal. However, an intense effort is being made to develop chemistries that will allow powder coatings to be applied to non-metal substrates such as medium density fiberboard. As a result, ongoing technological advancements are breaking down the barriers that have prevented the growth of powder coatings in the wood composites market.
What They Are, Why They're Used
Powder coatings consist of finely-ground particles of pigment and resin. These particles are spray-applied via corona discharge electrostatic guns or tribo charging guns, which administer electrostatic charges to the powder particles. Parts to be coated are grounded neutral, uniformly attracting the charged particles to product surfaces. The powder is held there until cured in a convection, infrared or ultraviolet oven where it melts and flows, producing an attractive and durable surface finish.
Perhaps the main reason for powder coatings' popularity is that they are dry finishes and use no solvents in any part of the application process. This eliminates the need for venting, filtering and solvent recovery systems to control volatile organic compounds released into the atmosphere. Furthermore, any spillage can be safely and easily removed with a vacuum.
In addition, powder coatings help create a clean work environment. These coatings come in a ready-to-use form and do not require mixing with any solvents or catalysts. Health hazards to workers are reduced as these coatings contain no VOCs which may cause eye, throat or skin irritation. Also, air used to exhaust powder spray booths can be recirculated directly to the plant, reducing the cost of heating or cooling makeup air.
Powder coatings can be applied either manually or automatically to horizontally conveyed or vertically-hung parts. Vertical applications help increase production and reduce unit cost as products can be racked closely together, allowing more parts to pass through a production line in a given amount of time.
Powder coatings offer a one-step application process that reduces the amount of training necessary for system operators. These coatings adhere uniformly to surfaces regardless of configuration, producing seamless edges that allow for greater design flexibility, and eliminate runs, drips, sags and other surface irregularities. Poorly sprayed parts, detected prior to curing, can be blown off with an air gun and recoated. Furthermore, approximately 95 percent of unused over-sprayed powder can be recovered, recycled and reused, resulting in maximum material utilization.
Powder coatings produce durable surface finishes that meet or exceed the performance characteristics of traditional laminates and liquid paints. These coatings resist cracking, peeling and marring and are abrasion, corrosion and chemical resistant.
Offering high quality, wide selection, high transfer efficiencies and low overall finishing costs compared to non-compliant coatings, powder coatings provide exciting new alternatives to the wood finishing industry.
Powder Coating Pluses
* One-step finishing process, no mixing nor priming required
* Materials are dry and contain no solvents or VOCs
* 90%-plus transfer efficiency
* Overspray can be recycled
* Easy cleanup with a vacuum
* Cured finish has good abrasion, corrosion and chemical resistance
Mike Favreau is marketing specialist, Morton Powder Coatings, Reading, PA. Morton's new product, Lamineer, is being introduced to the woodworking industry at IWF '98. For more information phone (800) 367-3318, ext. 6823.
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|Title Annotation:||powder coating technology in wood finishing|
|Publication:||Wood & Wood Products|
|Date:||Jul 1, 1998|
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