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Woodcraft optimizes rough mill productivity.

Using two separate gang rip operations, Woodcraft Industries' St. Cloud facility optimizes 50,000 board feet of lumber every day.

The rapidly increasing costs of hardwood lumber have become a constant challenge for woodworking operations all over the country. Three years ago, Woodcraft Industries, a manufacturer of cabinet and furniture parts, decided to fight back by investing in advanced rough mill equipment to increase its productivity and obtain higher yields.

"The boards we get today are smaller, shorter and narrower, which means we get a greater percentage of lower grade boards," said Steve Jacobs, manager of Woodcraft's St. Cloud Div. "We purchased the rough mill equipment to lower our lumber costs by using more of the wood we purchase. Also, the system is faster and safer because workers are not handling the boards."

Three years ago, the company installed two Barr Mullin Compu-Rip computerized, laser guided optimizing systems in its St. Cloud Div., in addition to installing a similar optimizing system at its St. Cloud door plant. Jacobs estimates that the new rough mill equipment has helped the company achieve a 55 percent overall yield from green scale lumber to the finished product.

"With our current computerized rip-saw equipment, we can tell the machine what kind of yield we want from each board. Regardless of the lumber grade, we are getting higher yields with our current equipment," Jacobs said.

Ordering ahead

Planning is critical for the company to be able to fill the orders of wood cabinet manufacturing customers such as Aristokraft, Norcraft, StarMark and WCI Cabinet Group. Woodcraft relies on a combination of the information provided by the optimizing equipment, computer estimating and past ordering experience to judge the amount of lumber needed to fill orders.

Its ordering schedule is based on a four-month inventory plan, a three-week sales projection and an IBM System 36 computer database to determine how much wood will be needed to fill orders.

Using mostly red oak, hard maple and white oak logged from hardwood forests in the upper Midwest, Kentucky, Tennessee and Indiana, the green lumber is trucked in and predried/kiln dried before it is ready for optimizing.

"Company-wide we get about 270 truckloads of lumber a month which totals out to 2 million board feet a month," said Steve Wilhelm, marketing manager with Woodcraft. "We have 550,000 board feet of dry kiln space and the wood is pre-dried before it is kiln dried. If production is beyond kiln capacity, we hire an outside kiln drier that will dry the wood to our specifications. We haven't been able to find kiln-dried lumber in the spot market that meets our specifications."

Cutting it close

Woodcraft practices a rip first operation versus a chop saw first operation because "that's the way we've always done it and we also make a lot of long, narrow pieces when it comes to manufacturing cabinet parts," Jacobs said.

The plant uses 40 percent #1 common lumber, 40 percent #2 common and 20 percent select upper grade. Jacobs added that defects such as knots, mineral rot, checks, splits and frost cracks are not circled with a chalk by hand, but are cut out by using the gang rip and chop saw operations.

After the wood is removed from the kiln at 6 to 8 percent moisture content, it is sent to one of two gang ripsaw stations. At the first station, operators feed the lower grade lumber through a Newman S282 two-sided planer and the planed lumber is conveyed to the laser guided optimizing station on the Barr Mullin Compu-Rip system.

The key to the Compu-Rip operations are the laser guides that aim thin red beams of light along the length of the board and which are coupled to a computer optimizing program. The Laser lights can be dialed wide or narrow to find the maximum usable width of each board.

The sawyer determines the maximum width with the Barr Mullin laser and computer screen. The board is then conveyed to a movable fence that, after a computer command, knows which width channel that specific board must enter before being ripped by a stationary arbor Mereen-Johnson 424 gang ripsaw. The ripped boards are conveyed to Precision chop saws with 14-inch blades and then either edge glued and assembled into panels in Taylor clamps or machined on Weinig moulders.

To optimize premium and #1 common grade lumber, the processing is similar. The higher grade lumber is sent through an Oliver Machine Co. Stratoline planer, conveyed to the Barr Mullin Compu-Rip optimization station and gang ripped on the Mereen-Johnson Select Rip with movable arbor. Waste from both saws is burned in the plant boiler.

"The 424 cuts ten percent faster than the Select Rip because the arbor on the 424 doesn't have to move for realignment like the Select Rip," said Jacobs. "But the Select Rip offers a two percent higher yield, so we cut the higher quality boards on the Select Rip."

Both saws use 10-inch carbide-tipped circular saw blades from North American Products Corp. Jacobs said the company sharpens its own blades but sends them out for retipping and hammering for balance. Each blade averages 100 hours of service before a blade change is required. Downtime for blade changes takes 20 minutes.

The quest for perfection

The new system is running smoothly, but getting to today's rate of optimization was not easy. Learning curves, some employee skepticism and some equipment changes turned out to be challenging.

"There were some bugs with the new system, and it took us about six months to get used to the new equipment," said Jacobs. "This high-tech equipment can't be run by the old-fashioned maintenance people who used to hold a hammer and an oil can. When I explained to our rough mill employees that this new equipment was going to make their jobs easier and faster, they were willing to learn. We've got an employee that's been with us for 41 years who was instrumental in making the decision to purchase the Compu-Rip and has been operating it since installation."

Another problem occurred when the company tried using thin kerf saws to increase its optimization. "The thin kerf blades on our gang ripsaws didn't hold up as well as our standard blades and the cuts they gave didn't give a good glue joint," said Jacobs.

Preparing for tomorrow

To make the most out of the raw materials, the company is looking at other markets, better optimization with other rough mill equipment and experimentation with fingerjointing.

"Even when we get in a load of white maple, some board will contain the darker heartwood. We are looking for applications where we can use woods that have differing colors," said Wilhelm. "We'd also like to see our cut-off saws operate on a higher yield principle so that we can be more profitable in that area. And finally, we'd like to experiment with hardwood fingerjointing. There are companies already doing it with softwoods, so why not hardwoods? The fingerjointing could even help reduce more waste."

Thinking about the future and the available supply of hardwood is very much the concern at Woodcraft Industries and the company is rapidly pursuing possible solutions.

"Today's boards are smaller and of lower quality," said Wilhelm. "Our industry must find ways to use more of the natural wood being produced."
COPYRIGHT 1993 Vance Publishing Corp.
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Copyright 1993, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Title Annotation:Increasing Productivity; Woodcraft's St. Cloud Division
Author:Derning, Sean
Publication:Wood & Wood Products
Date:Oct 1, 1993
Words:1219
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