Clip Off the Old Block
Ainsworth Lumber has taken its existing Lillooet veneer mill and carried out an $8.5 million upgrade to increase recovery
By Helen Johnson
Substantial increases in recovery and productivity have been realized at Ainsworth Lumber's veneer mill in Lillooet, BC, following a recent $8.5 million upgrade of its green line. And, just as important as the gains to the bottom line, is the security the upgrade has given to the mill's employees in a climate of competitive markets, layoffs and permanent job losses. The backbone of the upgrade was the installation of a complete Raute Wood system. "Basically, we completely updated our entire green line, starting with a Raute Wood lathe, complete with XY charging system, power driven back roll, and roller bar," says Mickey Forman, the plant's general foreman, veneer. A clipping trash gate, a three tray veneer transfer system to the new Raute rotary clipper, and a three tray random strip tray system were among other additions to the line. New mobile equipment included two 928 Cats with grapples and an 8,000lb Nissan forklift. Starting out on the log deck, a new metal detector over the slasher on the block line picks up any metal pieces and prevents them from getting into the mill where they could damage equipment or pose a danger to workers.
Two L & M block saws, complete with hold down fingers, were also installed, again partly for safety reasons. They allow shorter pieces to be cut without getting pulled into the saw, while giving a square cut on the logs, says Forman. "And they speed it up because we can now cut with both saws at once. Previously we could only use one saw at a time," says maintenance supervisor Bill Davidson. "From there they go to the 928s, complete with grapples, and the nice thing about the grapples is that you can keep a grip on all the logs," says Forman. "And we get bigger payloads," adds Davidson. From there the wood moves on to 10 concrete conditioning chests, three of which are new custom designed, precast models. The hydraulic doors on the new chests provide a more thorough conditioning because they make a better seal, says Forman. Both SPF and Douglas fir blocks are conditioned in the chests for about 24 hours, depending on weather conditions, in water ranging from 120 to 160 degrees Fahrenheit. The additional chests mean an increased volume of heated water is required. To that end, a newly installed $450,000 burner combustion system, developed by Inproheat Industries Inc. of Vancouver, augments two existing eight million BTU capacity LochheadHaggerty submerged burners.
"The third burner has a 14million BTU capacity to make sure we have sufficient heat, especially in the wintertime," says Davidson. "The other advantage of the new system is that it's reported to be more cost efficient to run per BTU and its all PLC controlled." From the vats, the logs are put on an entry system into the mill step feeder, which singulates the logs-increasing cycle times- and feeds them onto a precharging system where they are precentred. Then the XY charging system again centres the logs as close as possible to the chucks. "There are seven lasers that look at the log. It does a complete 360degree turn and all that information is fed into the software, allowing the best possible centering to get the best recovery out of it as you process it through the lathe," says Forman. "The new lathe has given us the ability to peel down to three-inch cores. Previous to that we were doing four and seven eighths."
Other features of the lathe include overhung Raute outer spindles that provide better support for holding the block, a three-inch big bar, the newest Raute power driven back roll and temposonic control cylinders for roll positioning. A variety of profiles, pressures and pitch angles can be programmed into the computer. From there the logs come out of the lathe and are processed through the clipping trash gate. "Ideally, it's set up to work off our XY charging system. As we're peeling wood out of the lathe, the clipping trash gate is programmed to clip at the area that we start to get recoverable veneer and it just speeds up the cycle time of getting wood down to our clipper quicker," says Forman. "Previous to that we would have to do some roundup, break the ribbon, pause for a second or two, close the trash gate and then start to proceed with processing wood down to the clipper," says Forman. "This does it in one step." Three trays, each with an Avtron DC dedicated drive, pass the wood through a moisture meter so different sheet widths can be clipped for different moisture levels. From there they are fed to the clipper and through a Ventek scanning system-which scans the veneer for the best clip recovery-and through the rotary clipper. "An overhead transfer system transfers our 54's down to an eight bin Raute Wood stacker with doublelength DC drives.
From there it goes through an automated strapping system where it's picked up by the forklift and put out into inventory," says Forman. "With the eight bin stacker we're able to do four moisture sorts, as well as grade sorts. Previous to that we had a two bin stacker that only allowed two moisture sorts and no grade sorting. So that's been a good addition for us." Fishtail, random and half sheet pieces are diverted to the green chain and delivered to a three tray random strip tray system that allows a constantly higher speed through the clipper. "The strip trays are a big help in that we can store 150 lineal feet of veneer before the clipper has to go down to a slower speed, so that keeps the line speed up constantly. Before, when we went to the green chain, we'd have to go down to 220 feet a minute to the clipper until we diverted," says Davidson. "Now we have the ability to chop up enough veneer to fill up 150 feet of tray before we have to go down, and that doesn't happen very often." The veneer is manually sorted onto veneer carts, delivered to an automated strapping system and packaged into 4' x 8' x 30" bundles and 4' x 4' x 30" bundles. After identification stenciling, the loads await shipping either by truck or rail.
About 70 per cent of the mill's product is shipped to Ainsworth Lumber's plywood mill in Savona, BC, and the remaining 30 per cent goes to open market customers both in Canada and the US. The mill's only other byproduct is chips from the three inch cores and waste veneer that are blown into rail cars and shipped down to Fibreco in North Vancouver. Wood processed in the plant is about 60 per cent Douglas fir and 40 per cent white wood, all sourced from an annual allowable cut of 348,000 cubic metres. The veneer mill, built in 1980, was taken over by Ainsworth Lumber in 1987. A retrofit on the lathe and some modifications to the mill were completed in 1988 and 1989. "This recent upgrade has basically replaced the old line with the latest equipment Raute Wood had for green end systems," says Forman. "The decision evolved around going through a supplier that could do a whole line rather than have piecemeal suppliers. Raute fit the bill for offering a complete system," says Davidson. "The upgrade has improved recovery by five per cent and productivity by 30 per cent, all with a 1.5inch reduction in our average log diameter.
We have also gained the ability to service our customers' needs better with the addition of the eight bin stacker," says Forman, citing the ability to cut down to a three inch core, the moisture clipping and the XY charging system as big recovery items. "We put out 137 million square feet of three eighths in 1999 and should be able to meet our target of 195 million square feet of three eighths for 2000," says site manager Gary Miller. The upgrade was intended to produce better margins, while keeping the staffing level at about 100 employees. "We have realized the improved economics with the new line and made the plant a safer place to work as well," says Forman, noting that the mill recently completed its first accident free year. "In general, the morale's been fantastic and I think everybody's happy with the new equipment. There's been zero job loss and the added economics of producing more with a better recovery has given everybody a better state of security in a very competitive marketplace," he says. "We're known for the quality that we put out of this mill. Feedback tells us that, out of all the Raute systems out there working today, our mill is putting out the best quality in regards to thickness and surface in our veneer. And that's necessary because the end use of most of our products is in the overlay plywood industry," says Forman. "And that's a result, really, of the effort that our employees have put into this plant. They are second to none when it comes to monitoring quality. They've been absolutely instrumental in the process. They are our quality control ."
This page and all contents
©1996-2007 Logging and Sawmilling
Journal (L&S J) and TimberWest Journal.
page last modified on Tuesday, February 17, 2004