Knock on Wood: Italian powdercoater brings out unique wood-grain finish

Leave it to the Italians—connoisseurs of such premier finishes as marble, granite and limestone—to master a unique way to apply a powder coat that mimics old world craftsmenship.

 

Decoral Systems USA Corp. in Coral Springs, Fla., is an Italian firm that offers a custom finish coating system to apply realistic wood grains, marble and granite effects among others on almost any material, including aluminum, steel, iron, fiberglass, glass and thermal resistant plastics.

 

“We offer turn-key plants for the decoration in wood-grain, marble, granite and custom design of metal and aluminum parts,” says Massimiliano Collicelli, sales manager for Decoral, which started in the U.S. in 2005 but received its first patent for the process in 1993.

 

The system seems simple enough: for example, raw aluminum surface receives a traditional pretreatment of a chemical conversion, creating a thin layer of amorphous oxide with coating.

 

 

An electrostatic gun then applies a 2.5-mil layer of special polyurethane powder paint. The polymerization follows with a 302-392°F temperature, depending on the type of powder, for 20 minutes. Collicelli says the base coat ensures adequate hardness of the final product and protects the aluminum from light, weather, abrasion, corrosion and humidity.

 

For the decorated finish, a preprinted film transfer with organic photosensitive pigments and cellulose resin is wrapped entirely around the part. The profile is positioned on the surface of a movable trolley and air is removed through a vacuum suction system. The result is a perfect thermo print, Collicelli says.

 

Finally, the trolley is placed in a special oven where the decoration is effected, as the ink pigments turn from a solid into gas and back to solid inside the paint layer. After cooling for a bit, the film is removed.

 

Collicelli says his system can duplicate any grain of wood, custom wood grain, any stone or marble surface, denim, peacocks, or any other design a customer can visualize.

 

“Something psychedelic from the sixties, we can make it happen,” he says. “Mock fabric, paisley, polka dot, stripes or sand.”

 

And how does it hold up?

 

Collicelli says the Decoral system exceeds stringent product standards and earned American Architectural Manufactures Association certificates and Qualicoat designation given by the European Laboratory and Research Organization.

 

 

Decoral even puts out a 130-page booklet showing quality tests performed on the finish. The company says pretreatment of aluminum should include yellow chrome, phosphor chromate or chrome-free cleansers. The layer thickness of powder coating must be from 60 to 90 µm, and curing at a minimum 15 minutes at 210°C, ideal 20 minutes at 200°C, and maximum 25 minutes at 195°C. It is also available as a low-temperature powder that needs only 302°F for 15 minutes for MDF and fiberglass, among others.

 

“The key factors for the best quality and results are right temperature, time and mechanical pressure,” Collicelli says.

 

Jim Hester from Quality Powder Coating in Carrollton, Texas, has been using the Decoral system to apply wood and natural stone finishes for several years, and says the powder coating market is moving to these types of applications.

 

“As we search to integrate alternative materials into today’s building and design, this new process allows for conservation of our natural resources, as well as an alternative to conventional finishes,” Hester says.

 

“Unlike vinyl tape that doesn’t look real and veneers which chip easily, these finishes are high-quality dye-sublimated powder coating made from high-definition photographic images,” he says. “They are so real, so natural looking, you have to touch them to know the difference.”

 

 

Hester uses a simple sales pitch when he talks with building manufacturers about using his products instead of real wood finishes.

 

“You will never have to worry about termites,” he tells them.

 

Coaters can buy a turn-key system from Decoral that includes a platform on a movable trolley in front of an oven. The system is comprised of two hinged parts—each holding a membrane—which closes manually as soon as wrapped profiles have been laid on the lower membrane.

 

After the upper lid has been closed, a pump creates a vacuum between the two membranes. This process facilitates perfect adherence of the transfer film on the surface, through concerted pressure of the upper membrane. Once the vacuum operation is finished, the frame is pushed manually into the oven, where it remains for 7 to 10 minutes until the decoration transfer is completed to a coating layer of 2.5 to 3 mils. A temperature probe controls the condition of the sublimation process. Depending on the unit purchased, the platform is able to hold parts from 35 × 40 inches up to 5 × 21 feet.

 

The coating products and transfer films are all purchased from and supplied by Decoral. Collicelli says, depending on the size of the powder coating machine, it might take from 500 to 2,500 sq ft of space in a plant to install a system.

 

 

 

 

Other systems—including hydrographic water dipping—have applied such unorthodox finishes, but Decoral says its system is more affordable.

 

Decoral says its application is perfect for entry doors, garage doors, windows, sunrooms, enclosures, store fronts, store fixture, appliances, awnings, elevator doors, decks and railings, ceilings, furniture other items.

 

“The wood grain on metal and aluminum wood grain finish is so realistic that it’s almost indistinguishable from real wood, even from a close visual inspection,” Collicelli says. “Our system of powder coating permeates the entire thickness of the coating, and as a result the coating cannot be removed by normal rubbing, chipping or scratching.”

 

Currently, there are more than 200 wood-grain finishes, 30 marble and granite effects, and 20 “fantasy patterns” available from Decoral, which it says has more than 500 licensees around the world.

 

Decoral’s Florida headquarters are equipped with several demo machines, so it can decorate samples at no charge for prospective customers. Lead time for samples is normally 10-15 days, Collicelli says.