A veneer plant, opened 40 years ago in White City, Oregon, has been owned by Boise since 1976. Five years ago a fire levelled its sister plant in nearby Medford and this prompted re-tooling and a big jump forward.
Disaster was to strike again when a forest fire in August 2002 singed 9,000 acres of company-owned forest and called for quick action to beat the bugs to the wood. The fire started on US Forest Service land, but quickly spread to Boise land. Plant superintendent Dave Anderson said: “We started logging that same week, before the ashes were cold.We have been peeling those logs since the fire.” At the time of WBPI’s visit in mid-August, he thought the salvageable logs would all be peeled by the month’s end.
Some of the company’s young plantations, established after harvesting, burned too, with nothing left to salvage.
Despite that quick action, Boise lost some wood. “We didn’t see much early deterioration, other than logs were a bit dry throughout the winter,” Mr Anderson said. “This spring the bugs started coming out and the worms started getting in there.We even have some stain in the Douglas fir.” Normally, blue stain deterioration is seen in pine; there was little pine in the salvaged stand.
The US Forest Service fought a half-million acre fire nearby at the same time. Hamstrung by preservationists’ opposition to timber harvesting, they have yet to recover the burned forest’s value and prevent complete loss. Several Oregon State University forestry professors studied the problem and called for immediate action.
The Forest Service had produced a plan with alternatives ranging up to 450 million board feet of salvage while the forestry professors advocated salvaging up to 2.5 billion board feet. That much of the fire area is in a federally designated wilderness area, where road building and other activities are off limits, complicates the matter further.
In any case, work would not begin until next summer, after bugs and fungi have had more than a full year to build their numbers.
All of Boise’s logging is contracted, with logs delivered to the logyard where LeTourneau and Caterpillar 950 and 956 front-end loaders handle them. The Cats offload debarkers, stack on the ground, fill and unload vats and feed the lathe decks. A new 4ft lathe and another converted to high speed triggered an extra debarker shift. The logs are sprinkled to prevent deterioration.
A typical log mix was to be seen in July when there was 78% Douglas fir, 10% white fir and 10% pine. Most of the pine is ponderosa with a small amount of lodgepole. Monthly veneer production in two ninehour shifts is about 24 million ft2, 3/8in basis.
“We’ve been peeling the fire logs as fast as possible, usually within a week of their arrival at the mill,” Mr Anderson said.
The company’s adjacent sawmill handles debarking and bucking with a Salem 65in rosserhead and Kochum Cambio 30in ring barker. Earlier, the veneer plant could handle blocks as large as 80in in diameter but, at the time of the revamp following the plymill fire, they decided that 45in would be the maximum.
Highest recovery is necessary with contemporary high wood costs. On the 4ft line, they can peel down to a 21/8in core.
They sort for diameters at the debarker. Seven inches and under usually goes to the 4ft lathe. The debarkers remove any charred wood on the fire-killed logs.
The bucked blocks are forklifted to the 14 steam vats that have been converted to hot water at around 155°F. Mr Anderson said: “Steam sort of dries your blocks. Water seems to soften them and does a more even job of heating them. It’s quicker, too.We reached the point where we couldn’t get our logs hot in the winter.”
He said in summer they run pine off the ground ‘cold’. “It might be 100°F outside, so it’s really not cold. If you get a block too hot, it gets soft and will spin out on you.”
The mill runs two shifts totalling 16,000 to 18,000 blocks daily, including the 4ft lathe. Most of the lathe work has been by Coe Manufacturing.
Coe converted a Premier lathe. All Coe x-y systems and chargers are installed. The two 8ft lathes are powered by 450hp and the core lathe is 160hp. Elite controls are on the ‘A’ lathe with Raute on the other two.
The mill has clipping trash gates on the 4ft and ‘A’ lathes. These save time – 0.7 to 0.8 second, “And help you gain constant thickness, too, from not going in and out of your peel,” said Mr Anderson. Lathe cycle times are as short as four seconds. The computer follows everything with cycles timed to fractions of seconds. Milliseconds, when added together, can result in savings.
Mr Anderson said: “Sometimes you might not be able to identify a problem. With this data, you might find the charger coming in a little bit slow or the core drive coming in slow, or chucks not retracting quickly enough.”
Plant management has weekly maintenance meetings to find such solutions.
When planning the mill revamp following the plywood fire and the decision to consolidate veneer production at White City, they discussed the merits of two- versus threetray installations for the core lathe. They built so that adding a third tray would be fairly simple, but found that two trays were sufficient. A Lloyd Controls following system works well.
The trays are generally long enough to handle the blocks assigned, but if a ribbon is too long, the clipper takes over the lathe speed. Veneer is never broken at the lathe.
The core lathe speed is about 1,000fpm while trays unload at the clipper speed of about 500fpm.With the clipping trash gate, very little material goes to the hog. Nearly all goes to the clipper.
Boise crews built the core line tray system followed by a Raute three-bin stacker. One chain puller works at the end while four chain pullers work on the two 8ft lines.
There are Elite controls for the ‘A’ lathe and clipper and rotary clipper with Ventek scanners on all three lathes.
Boise doesn’t clip just 27in and 54in, but includes random widths up to 33in. That means an additional 6in of wood recovered than if a 27in had been clipped. Normally that would have gone over the end of the chain. This recovery benefit is gained by the fact that the green end’s customer is the company’s own plywood mill, with its composer handling random widths.
An important market is Boise’s LVL mill just a half-mile away.
As with most mills, safety is an important consideration. This mill has a better record than most, in fact 1,682 days without a lost-time accident at the time of WBPI’s visit. Everyone participates in safety, watching out for each other in the mill. This extends to project work.