Pullman Wash -- For lumber mills, the higher grade yield of Machine Stress Rated (MSR) or Machine Evaluated Lumber (MEL) means higher profits. MSR is a thorough and cost-effective lumber grading method utilizing special machines to bend or "stress" individual boards to evaluate stiffness. MEL and E-Rated lumber grades can be produced in the same equipment.

Contractors and truss builders who demand the highest quality material are turning in greater numbers to MSR and MEL lumber grades. Lumber mills have capitalized on this growing demand by installing MSR grading machines, however, many mill operators mistakenly believe they do not have space for new MSR machinery and that creating space would be costly and unprofitable.

The size of MSR equipment is not the only factor. The layout of other milling machinery is also important, and some degree of mill reconfiguration is almost always necessary. However, equipment can be fit by adding conveyors or rerouting the path of material and even with the most complicated installation, MSR grading can still produce profitable returns.

"When we’re installing these machines into a mill, it isn’t just about size, it’s also the layout of the mills," noted James D. Logan, president of Metriguard, Inc., the world’s leader in MSR lumber production equipment. "There might be two mills that are laid out alike somewhere, but I haven’t found them yet. Every installation is a custom installation. Many people think we can’t get the equipment in, but we can."

Metriguard has custom-fit nearly every machine they’ve sold. Their engineers have never failed to make the MSR equipment work, and more often than not there is a cost-effective solution that will pay off with higher profits in the future.

Mill owners often envision bankrupting costs when they consider altering their operations to accommodate new machinery. However, even with several modifications, the financial returns can be substantial. For suppliers who have squeezed all the volume they can get from reduced kerf widths and target sizes, increasing grade yield is the best opportunity to improve revenue, because a higher grade sells at a higher price.

"The most complicated installation might cost around a million dollars, but if a mill is making $6 to 8 million on MSR a year, that’s still a pretty good return," Logan noted. "Sawmills that specialize in MSR lumber can show a very nice return on their investment for this equipment."

Truss builders have saved money by installing MSR equipment at their sites as well. They purchase lumber, regrade it and build it into their product with full assurance of its performance. Around 10 to 30 percent of non-MSR wood is unusable for some truss builders because of knots, wane or other characteristics.

End users have become more concerned with avoiding lumber failures. Dismantling and reassembling structures because of faulty lumber costs construction companies a fortune in lost resources, time and labor. One truss manufacturer saves over $100,000 per year in man hours alone by using MSR lumber that eliminated a five-man repair crew. MSR lumber can also help prevent structural failures at the end of the line and other problems like Ceiling-Floor Partition Separation—gaps between ceiling or floor finishes that open in winter and close in summer.

The machine that makes custom installations possible is the Metriguard 7200 High Capacity Lumber Tester (HCLT), the latest MSR/MEL grader which can evaluate up to 2000+ ft. (600 m) of lumber per minute. Its tunnel design means fewer plug ups and less downtime and it can accommodate a range of sizes from 2 x 3 to 2 x 12, and metric 35 x 70 mm to 45 x 290 mm. The HCLT is EC certified and produces all machine grade categories including MSR, MEL, MGP, MSG and E-Rated Lumber.

Ideal installation of MSR/MEL equipment is in the production line between the planer and the "slow-down" belt, avoiding as many turns as possible. The design of the 7200 HCLT allows boards to be run flat, rather than having to be turned onto their side like other MSR machines. This means fewer operations to roll the wood into position, so boards exit the planer directly into the grader.

Older designs for MSR equipment required far more space—17 feet for the machine, plus the length of the lumber to be processed, plus five additional feet. That means processing 20 foot boards requires a total of 42 feet of space for the machinery. The 7200 HCLT is only about 15 feet long, and with an optional drive system, virtually no space is required between the planer and the grader. Often the grader is installed right outside the exit port of the planing room.

However, some mills don’t have space between the planer and the slowdown belt for the grader. Another common problem is having the planer in an odd position, such as 15 feet above the mill floor or even underneath the sawmilling operations. Both of these problems can be addressed in a variety of ways, including installing additional conveyors, simply moving equipment, or more complex adjustments to the layout of the mill.

In one mill, sawmill operations were located above the planer, yet both shared the same sorter. Large steel posts supporting the operations above were in the area that needed to be clear for the MSR equipment. In that case, Metriguard suggested rerouting material on additional conveyors. The mill installed bridges over the area and removed the posts to create a clear space.

"The mill always has to make changes when the equipment is installed. Sometimes it is insignificant, other times it is major, like building bridges," Logan said. "It’s very seldom a drop-in case, unless the mill was designed with space left for the equipment. Those are the dream installations."

One of the most complicated installations involved a sawmill in Canada, where the mill hadn’t left enough room for the MSR equipment and as a result required complex conveyor systems and custom machine fittings.

"They brought the material down to the sorting machine, dropped it out onto a belt that carried it lengthwise onto a sloped set of chains. From there it was accelerated and shot it back across the chain through the machine onto a new grading chain where the visual graders were located," Logan explained. "From there it went into a new tray sorter front-end which routed the lumber back to the rolling trays in the sorter. They built an identical front-end for the tray sorter and carried the material back to the trays with individual belts. It was complex, but it worked and is still working."

"My message is that when you design a new planermill, leave room for the equipment," Logan advised. "But, one way or the other, we can help get the job done—we haven’t found a mill yet where we couldn’t fit our equipment in. We will find a way for you to maximize your returns with MSR lumber."

For more information Metriguard’s 7200 HCLT Stress Rating machine and how it can be fit into your application, contact Metriguard Inc, at PO Box 399, Pullman, WA 99163, or call (509) 332-7526; or fax (509) 332-0485; e-mail sales@metriguard.com; or visit on the web at www.metriguard.com.