RadEX banks on the 'UV cure': RadEX's gamble on a million-dollar ultraviolet-curing line has made short work of curing powder coat finishes on MDF.

Five years ago, RadEX took a Leap of faith in deciding to use uLtraviolet light to cure powder coatings on MDF.

It was a new technology to North America. So new, in fact, that only one other company in North America was doing it. General Manager Glen McLean and Plant Manager Rick Grim, both of whom already had experience in thermal-curing powder coatings on metal for H&G Powder Painting, researched UV-curing wood powder coatings for two years, including making two trips to England to compare and contrast thermal- and UV-curing operations at woodworking companies there.

Ken Giles, owner of H&G and RadEX, both of London, ON, backed McLean and Grim's decision to go UV over thermal cure. The company invested $1 million to install a Line for powder coating MDF on a contract basis.

Being only the second UV-curing Line for this application on the continent presented its share of drawbacks, though. Convincing customers, who were unfamiliar with the UV-curing process and powder coatings in general, to switch to it from their trusted finishing methods, despite the many benefits of UV curing, was tough, McLean admits.

"It's hard getting people to change from what they already know, especially when it is a new technology," he says.

On the bright side, RadEX managed to Line up deals with potential customers, including Global, a Canadian office furniture manufacturer, Steelcase, Starbucks and HMV, a Canadian CD and DVD retailer. McLean says RadEX expected to have more than $1 million in sales its first year. Not bad for having not even opened yet.

But, only a few days after officially starting production, September 11 occurred.

The deals RadEX thought it could count on were derailed by the economic uncertainty that the terrorist attacks created. Businesses all over North America--and not just woodworkers--clammed up their orders.

RadEX had to start over.

McLean and Grim set out to reclaim RadEX's business and educate the industry about its services. They visited office furniture manufacturers, store fixture manufacturers and anyone that might want powder coated MDF parts so they would no longer have to contend with edgebanding, T moulding or hard edges, all white getting a harder, more stain-resistant and seamless finish.

McLean and Grim told their potential clients that RadEX's products are cost competitive with high-pressure laminates. They told them that the complaints with older, thermally cured powder coatings were not valid in UV curing. The tow-temperature requirements in RadEX's fine would not scorch the substrate, which results in a toss of structural integrity or moisture evaporation that causes coating failure or dries out the hard edges and corners of a part.

McLean and Grim produced hundreds of samples to illustrate this, but had a difficult time hooking businesses. That is not to say there was no business after Sept. 11, 2001, but the office furniture market RadEX specifically targeted suffered particularly bad times.

Slowly but surety, their efforts over the last four years have reversed that trend. McLean admits that more customers are needed still. Right now, a medical products manufacturer in Wisconsin is RadEX's biggest customer.

Most of RadEX's business is repeat business, but new customers are also coming on board. RadEX is looking for customers who need something every month, rather than once a quarter or once a year, which is how a tot of the company's customers order now. Though each month proves better than the fast, McLean, Grim, CAD/CAM Manager Bob Jones and U.S. Sates Manager Steve Couzens still find themselves having to educate the industry on the merits of the company's services.

"[Thermal-curing, HPL and paper laminates] are all good, and they all have their place," McLean says. "We are an alternative. If you like what we do, you like the finish and you like the price, then here we are."

In the Office

Jones is the first to see the 2-D or 3-D drawings sent in by customers. He prefers the images come in a neutral format (DXE or IGS).

Either way, Jones extracts the data from the rites and then determines how to make the piece. This step, Jones says, is the most difficult and time-consuming--or at least it can be.

Jones goes to work importing a 2-D or 3-D rite into AlphaCAM, drawing up the details, figuring out how to arrange the router toot paths and how to soften the edge, which RadEX recommends on all its finished products. This process could take him several hours if he has a complex 2-D drawing, or no drawing to work from. Often times, though, because of his background in aerospace drafting and engineering--and assuming the image is submitted correctly--Jones can program the part rather quickly.

"I'd say a couple hours later, you have code at the machine," Jones says. He and Grim agree that the process is so fast, a part could come off the UV line completely finished in about two hours--though, they add it is highly atypical for them to get an order that requires that quick a turnaround.

In the Shop

Machining customers' parts was not in the company plan when opening for business. However, when several customers asked RadEX to manufacture their parts, the company purchased two used routers: an Anderson and an AXYZ.

"Most of the customers ask about it, or at least ask us to quote [machining and finishing their parts]. Most companies want to design and maybe assemble. They want us to do the manufacturing, they want us to do the subassemblies --that's become commonplace in the industry. They outsource it, get it back, box it up and ship out to their customers. Designers ask us to do everything, from start to finish."

"We initially just wanted to have them send the (pre-machined) materials, so we could finish it and send it back," McLean adds. "We found out that we had a lot of inquiries asking, 'Can you make it?' We though that if we could control it, then we could choose the MDF, we could machine it and we could have a lot more control on the paint line. So we purchased a couple of CNC machines."

The code Jones produces is sent to one of the two routers, most often the Anderson because its twin tables allow for better work flow, Jones says.

RadEx uses MDF and HDF from Temple Inland, Georgia-Pacific and SierraPine, and moisture-resistant Extira from CMI. Jones says the panels are extremely important to their machining process, as well as the finished product.

"Every thickness of MDF acts differently, every powder acts differently, different wood manufacturer's MDFs act differently," McLean adds.

While RadEX only buys panels from about a half-dozen MDF manufacturers, if a customer delivers already-machined panels to RadEX, then that is what is used, regardless of brand.

After panels are machined on the router, they are sanded. For now, RadEX hand sands all the parts that come off the routers; also in use is a SlipCon wheel sander. RadEX currently is looking to purchase an automated sander to help eliminate some of the time spent on hand sanding, as well as considering buying a new router.

"We have considered getting a new router," Jones says, "one that runs on G-Code so we can run one machine, then, when that is done, the other one can keep working. The idea is to get a machine that is similar to that one, with G-Code so one operator can run both machines."

On the Line

The million-dollar investment to install the powder coating line is starting to pay off because of the speed of finishing once a part is on the line. On the surface, it is amazingly simple.

Loading: Workers load the parts onto the 350-foot-long overhead conveyor, which is manufactured by Jarvis Webb and is capable of moving at speeds up to 18 feet per minute, though RadEX has not needed to run it that fast. Twelve feet per minute is the average. McLean says that, in his experience, thermally cured lines run at 6 to 8 feet per minute.

Grim says the conveyor has been modified to accommodate parts up to 5 feet wide, 12 feet long and 2 inches thick; the load bars from where the parts are hung can be removed and spaced as needed.

"We can run different shapes and different thicknesses," Grim adds.

Pre-heating: After hooking parts on the conveyor, the parts move into a Nutro Coyote infrared/convection pre-heat oven. Grim says either or both infrared and convection heat can be used to heat the surface--and only the surface--of the board.

The infrared heat helps RadEX avoid heating all the way through because it heats from the outside in, while convection heat works from the inside out. Since thermal curing uses only convection heat, the entire part is heated completely through.

With less heat, the structural integrity of the board is unaffected, like it may be when thermally heated, McLean says. In addition, the high temperature requirements of thermally curing powder coats add energy costs.

The oven is set to a different temperature or a different heat source for each shape, each thickness and each type of substrate. The entire pre-heating process takes 1 to 2 minutes, Grim adds.

Applying Powder: As the part comes out of the pre-heat oven, photo sensors signal the automatic powder guns to spray, creating a cloud of powder. This cloud picks up the flew of electricity emitted by the electrostatic spray guns and a thin coat of powder is applied to the part surface.

RadEX uses 16 powder guns--12 automatic and four manual--in the powder application stage. The automatic guns are used most often when the parts are of a simple design, such as a desktop or shelving, and the manual guns are for the more complex designs like the X-ray cart handles that were being finished when Wood & Wood Products visited the shop.

Compared to the 6 to 8 microns of powder that McLean says is required for thermally cured parts, UV curing only needs 3 or 4 microns, which is what RadEX applies. Changing over from one powder color to another takes anywhere from 20 minutes to an hour, depending if reclamation is required, Grim says.

RadEX credits Protech Chemicals for providing much-needed support in the beginning stages of the business. The powder coating supplier helped educate McLean, Grim, Jones and the others in UV powder coating. Protech's Nuvocoat comprises the bulk of the powder used at RadEX.

Melting and Flowing: Upon exiting the spray booth, the conveyor carries a powder-coated part into the "gel" oven, where another Coyote infrared/convection oven--operating at about 250F, depending on the substrate thickness--activates the powder in about a minute, causing it to melt and flow over the surface of the panel. After this quick heating, the part travels to the UV oven.

UV Curing: Fourteen UV lamps are positioned at Left, right, top and bottom within the Fusion UV chamber--all of the Lamps angled differently to cure every area of the part. The trip through the curing Lamps lasts only a matter of seconds, resulting in a completely cured part.

Cooling Down: Grim recalls that one English thermal-curing company he visited snaked its conveyor high into the building's rafters after exiting the curing oven. This was to aid in the cool-down stage and added about an extra 25 minutes to the operation.

RadEX's conveyor comes directly from the UV oven makes a sharp curve, totaling about 50 feet, at which point parts are coot enough to touch and unload. From there, RadEX workers can wrap up the parts and get them ready for packaging and shipping. The entire process takes, on average, about 30 minutes.

Always Working

Mclean and the rest of the managers agree they face an uphill battle in getting more customers. However, they say that when they do get customers, they keep them because of the speed and quality of the finish. White business continues to increase everyday, they stilt have to pound the pavement to convince new customers of RadEX's and the UV Line's worth.

The managers admit that UV-cured powder coated parts do not have as smooth of a finish as thermally cured parts. They boast that they are perfecting it day to day, and soon it will be comparable.

One finish that is relatively new to the company is an antimicrobial powder coating by DuPont Powder Coatings. It contains AgION, a compound that protects against bacteria, fungi, yeast, mold and mildew. RadEX hopes this will be a big hit in the medical furniture manufacturing sector, as well as in day cares and schools.

RadEX has started UV curing plastics and is Looking into the feasibility of curing assembled car components. The tow-temperature requirements would not affect the rubber seals or the grease within the part, McLean says.