December 2004

Automating the Profile Finishing & Sanding Process

Three companies boost their productivity with automated profile finishing and sanding equipment

By J.D. Piland

A profiled moulding can add just the right accent to a room, cabinet or any piece of furniture. Often times, there is more to making, especially sanding and finishing, a wood profile than meets the eye.



Depending on the detail of the profile, sometimes a given sander cannot smooth out all the nooks and crannies or the finishing equipment cannot evenly coat the entire surface with the appropriate amount of stain. This can require repeating the process to correct any mistakes or misses. Not to mention the labor required. And then there is the drying time...

An employee at Middlebury Hardwood Products feeds product into the company's new Cefla UV coating system. An Opti-Sand profile sander was added as a denibbing unit.

New automated profile finishing equipment and profile sanders have improved that process. They can eliminate the need to make multiple passes, unless a high-end finish is desired. In addition, the finishing material can be reclaimed and the labor sometimes consists of just loading and unloading the machine.



The automation offers a more effective production process compared to hand finishing and sanding of the past.



Wood & Wood Products talked with three companies that use automated profile finishing and sanding equipment to see just how much this aspect of woodworking can cut costs and labor, and eventually increase productivity many times over.



Each of these companies either used to complete their finishing processes by hand or outsourced. In the interest of saving time and money, and having self-control, each company bought a profile finisher or sander to bring the processes in-house. The results were dramatic and their production has gone through the roof. The three companies W&WP interviewed include:



* T.W. (Two Women) Painting & Prefinishing, Brooten, MN: Mary Jane Schmitz and Heidi Kinzler, co-owners of T.W. Painting & Prefinishing, used to do all their finishing by hand in a spray booth. The company has used a Delle Vedove UVC/200 vacuum coater, plus FUV 7 UV oven, for six years. Two Superfici flatline systems were installed in August 2004 and have helped reduce finishing times on a door from 15 to 3 minutes. T.W. Painting runs its vacuum coater at about 100 feet per minute and the flatline systems at 400 feet a minute when running moulding, Schmitz says. At the end of a good day, and at those speeds, she says they produce an average of about 25,000 linear feet.



The flatlines, Schmitz says, are sometimes used to stain the mouldings. Mouldings are laid side by side and run through the sprayer. T.W. offers color matching on millwork, including doors, trim, windows and cabinets; the type of finish and topcoat runs the gamut to accommodate the customer, Schmitz says.

An employee at T.W. Painting & Prefinishing loads the Delle Vedove UVC/200 vacuum coater.



* Moulding Solutions, Chinquapin, NC: This eastern North Carolina moulding producer purchased an Opti-Sand L202 profile sander two years ago and in February 2004 installed Delle Vedove UV spray equipment. All of its products, which are covered on four sides for a moulding track system, are finished with a sprayable UV material with aluminum oxide for better protection. On the finishing line, Moulding Solutions produces about 5,000 linear feet a day, President Chris Jones says.



Moulding Solutions used to outsource its finishing, but as a cost- and time-cutting venture, brought the finishing in-house. The company offers hundreds of stain colors and top coats with a UV clear coat.



* Middlebury Hardwood Products Inc., Middlebury, IN: Middlebury Hardwood is slightly different from the other two companies in that it does not run profile mouldings, but rather lineal stock for face frames. Despite this, the company purchased equipment for producing profiles in February 2004.



"We go through all the same steps as you would [for profile finishing]," COO Del Miller says. "We could tomorrow morning run profile moulding." The company has a Cefla/Falcioni Profiplus 26 and spray machine and a UV Unisprayer and a sanding/denibbing unit from Opti-Sand.

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Like Moulding Solutions, Middlebury Hardwood outsourced its finishing. But in order to reduce cost and required inventory - and to get rid of the drying ovens and racks to free up floor space - Middlebury Hardwood decided on the UV finishing line, Miller says.



Most batch orders are 200 to 300 linear feet, Miller says, so a flexible system to accommodate quick changeover is essential. "Having our stain line separated from our UV line allows us the flexibility to run small batch orders by color, and then maximize the UV finish line to its potential independently." In November, Miller says the company ran 250,000 lineal feet of product.



Smoothing Things Out



As any woodworker can tell you, sanding is one of the most important operations when applying a finish to a workpiece. It is essential in providing a surface that holds the stain or the finish coat and, in turn, gives the final product a quality, desired sheen without sanding through it.

Profile sanding sometimes can be more complicated than just running any piece through a widebelt or drum sander.

Middlebury Hardwood Products employees unload the Cefla UV coating system.



One of the keys to profile sanding is the spindles. Miller says when his company decided to bring its finishing applications in-house, it went with a flat wheel sander from Opti-Sand, and one of the main draws to the machine was the flexibility it provided. In fact, due to the sander's modular construction, he says the sander was taken apart and made into two separate machines for denibbing, which is in line with the stain operation, and sealer sanding.



Miller says the sander initially was not going to be in the finishing line, though it would still be used for finishing applications. But, since the sander has variable speeds on the spindles, it was determined to be a worthwhile venture.



"It's really crucial that if you put [the sander] in the line you have [one] that has variable-speed spindles on the sanding heads," he says. The variable speeds allow you to be "aggressive enough, along with the grit of your sandpaper, to run at the same feedrate that your UV line is running."



At Middlebury Hardwood, "we can have each head at a different speed - depending on which wheels we want to be most aggressive - and we can have each wheel at a different rpm," Miller adds. The denibbing wheels are run at 165 rpm and the sealer wheels at 235 rpm, all with 180-grit abrasives.



As with many cost-cutting operations, this aspect of profile sanding allows the piece to pass through just once. Not only that, the variable speeds can help determine what grit of paper is necessary on each head, Miller says. "It allowed us to pick the right mix of what grit of paper we wanted in conjunction with the rpms of the sanding head to get the quality of sanding we wanted and not have to impact or sacrifice the speed of the line."



Profile sanders utilize sanding wheels, which have "sanding fingers," as Jones calls them. These fingers - or strips - are individually attached to the sanding head, making them easy to replace.



Moulding Solutions uses its Opti-Sand profile sander for denibbing operations. Therefore, the company uses 120 grit and runs the machine at full speed during the shift. Though the grit is not very high, Randy Jones, vice president of Moulding Solutions, says they still interchange the strips in order to get the most use out of their sanding strips.



Right now, they use a color-coded system for replacing the fingers; blue strips are changed first, then red. Alternating the sanding strips does not bog down on the wood and gives it a more polished finish.



"Sometimes it sands better with some old and some new, than it does with all new," Chris Jones adds. "[It] depends on how much is used and how heavy the sanding we are doing is. But most of the time, for our denibbing application, we rarely have to change the heads - maybe once a month. We don't change the heads themselves, just the paper that goes in them.



"You can give it just one setup and then change it for the thicker or wider stuff, and that's about it. For the narrow stuff, we actually use some extra-size sanding heads that can feed multiple pieces at a time, like four or five rather than just one." But that only applies to the simpler profiles, like a quarter round, he adds.



Miller says Middlebury Hardwood does not change the sanding wheel at all anymore either, but does switch out every third strip. "[It] allows us a longer life on the sanding wheel, reduces our sanding costs, and at the same time improves the sanding capability," he says. "You can change each little insert in a matter of about 10 seconds apiece."



The Finishing Touch



Installing a UV vacuum coater or an automated spray machine will boost productivity several times over, Schmitz says.



Before purchasing a Delle Vedove UV vacuum coater six years ago, Schmitz says the company did all its finishing by hand in a spray booth. But, upon installing the machine, "in an hour and a half, we had it done. It went from something that took days, into hours, literally.



"It's able to provide my customers with economical pricing that they need to be able to sell that moulding," she says. "And it gives me the opportunity to keep up with customer demands. Now I am able to work with manufacturers of mouldings. It makes that much difference. Otherwise, I might just be a five-person shop."



Jones echoes the importance of the UV finishing equipment. Moulding Solutions' Delle Vedove UV spray equipment helped the company "triple our capacity because we don't have any drying time or rack space," he says.



The drying time, or lack thereof, has dramatically improved all three companies' production; for each facility, because of the UV curing times, all of the pieces produced can go directly to wrapping and packaging.



Cleaning House



There is much more to it than just purchasing UV spray equipment and the drying aspect. One of the most important tasks is to clean and maintain the filters, or in the case of sprayers, the guns.



"The key ingredient, from a personnel standpoint," Miller says, "is making sure that housekeeping or preventive maintenance - like changing the filters, cleaning the guns - is done on a scheduled basis. To eliminate your downtime, you want to make sure your guns are cleaned periodically and not wait until they are plugged." The companies generally clean at the end of the shift unless a different finishing material is necessary.



Miller says the maintenance schedule for Middlebury Hardwood includes cleaning and inspecting the guns and gun tips every 25,000 to 30,000 feet (about every other day); every 40,000 feet the filters are cleaned or changed. Gun cleaning, based on 10,000 feet, is typically about twice a day. T.W. Painting and Middlebury Hardwood both registered at about 10 to 15 minutes to maintain these essential elements.



When ending a day's production, Jones says: "Make sure you strain it when you reclaim [material] and seal everything. [Some] say you can leave it in the machine overnight, but we've found that you have to flush it out every night or it will stop up your filters and slow you down a lot because you have to keep cleaning them out. We flush it every night and then put some solids in it and leave it overnight. Then just make sure your solid is out before you start running UV through it."



The thing that occupies more time is changing over the finishing material. Typically the changes take about 30 to 45 minutes, regardless of gloss levels.



Those interviewed for this article say the single most important aspect of finishing is the product you are using for the finish.



Each company went through several test runs with different suppliers to determine how well their respective product would turn out on the new equipment.



The finishing material affects most aspects of the machine and the process, including material changeover, clean up and number of passes. For example, a catalyzed varnish or urethane can create more sanding on the piece because it may cause some wood species (like oaks and ash) to "tick again," Jones says, necessitating another denibbing pass. "There was some hand sanding involved in that, which was a nightmare," he adds, referring to the previously used finishing products.



Adding to those issues, Jones faces a problem in the shop itself. It is located in North Carolina and the humidity can get high, which can cause the piece to be rougher, and then require another pass on the sander.



All three interviewees stress the importance of working closely with the finish supplier to achieve goals.



As for the UV machines themselves, Schmitz says they are pretty simple and not prone to breaking down or needing much maintenance, simply because "there's nothing to go wrong with [them]." The only things, she mentions, that really need routine replacement are the UV bulbs and filters. But as long as proper care is taken - knowing the number of hours the bulbs can run, cleaning techniques and not to touch them - then replacement of the bulbs may only need to occur about three times a year, even if the machine is run everyday, like T.W. Painting's machine is.



The benefits of profile finishing and sanding equipment, when compared to outsourcing or hand finishing, are tremendous. Just buying the equipment upped the productivity for each company interviewed and has led to more customers and more orders. Not only is the equipment relatively easy to use, it does not need much maintenance and lends itself to additional units for effectively finishing various products.



Schmitz says she no longer rejects large orders because she knows she can get it done with her automated finishing equipment.

                                                                                                                                                                                           

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