The Roy O Martin mill in the tiny timber town of Chopin, Louisiana, just got bigger with an entirely new Coe high speed small-log lathe line, dryer, lay-up line and press. This was a US$56m project. By the second quarter of 2008, when up to full production with the new addition, the mill will be turning out nine million ft2, 3’8in basis, of panels weekly with a current staff of 528.
Martin is not lacking for raw material. It owns 580,000 acres of Forest Stewardship Council-certified timberlands, with its mills placed in the most efficient locations for minimum hauls. The firm is vertically integrated into plywood, OSB, hardwood lumber and poles for the transmission industry.
Most raw material comes from a 30- to 35-mile radius and while much of the logging is contracted, Martin also has a subsidiary logging company.
Joe Mackay, the company’s plywood vice-president, said, "Our log yard has l8in thick concrete. We can store at least 30 days’ of wood on the slab, but we don’t tend to leave that much out there."
Rain slows hauls in the January to March period, but volumes are fairly steady through the rest of the year.
A Taylor log stacker, Volvo 340, or Caterpillar 96 unload and handle logs, with about 80 truck loads arriving daily, seven days a week. For the new line, a LeTourneau rotary crane loads the deck to a PSI unscrambler and singulator to a Nicholson 27in debarker. Oversize goes to the existing log processing.
Two scanners can handle tree lengths up to 62 feet. This provides a dimension scan for plywood blocks as well as identifying poles for length and class. Poles are treated at Martin’s Pineville mill.
The small tops are chipped in a large Valon Kone 600hp chipper, while the blocks, sorted for diameter, move to one of six vats for 160ºF (71oC) water conditioning for 12 to 16 hours, producing core temperatures of 105ºF to 110ºF (40-43oC).
A Linden log ladder leads up to the Coe turnkey-project lathe line, equipped with a camera-based x-y charger and Alpha Omega software for optimising block positioning. The system peels an average of 12 blocks a minute, with a peak of l6.
Three-stage retracting chucks are included, with the smallest being 21’2in. Veneer off-bears by a clipping trash gate onto three 100ft trays and to a Durand-Raute clipper supported by Ventek software. A Coe diverter directs veneer to a pair of two-bin stackers.
Included in the expansion project was an 18-door Coe jet dryer with Accumatic vacuum feed and 14-bin Coe stackers.
On the original 1995 line a Raute 28in lathe, with Elite x-y scanner upgrade, handles blocks 12in and larger. "We segregate around a 10in block to the Coe lathe," said Mr Mackay.
Veneer from the Raute goes to four 120ft clippers and to a Durand-Raute clipper, two three-bin stackers and a short green chain for strip and fish-tail.
Three existing Raute jet dryers are fired by two Wellons furnaces with 74 million btu/hour capacity each, assisted by a new Teaford furnace producing 80 million btu/hour. Heating is totally by thermal oil.
Two 29-section Raute dryers are installed, along with a 20-section Raute for re-dry and strip. The output of each of the large Raute dryers goes through either a Ventek GS2000 defect analyser or a Mecano veneer defect analyser into a 14-bin stacker. Ventek, Sequoia and Sentry moisture meters are installed.
"We have a high-moisture drying programme so we sort into four different moisture sorts in five different grades," Mr Mackay explained.
Such moisture content emphasis is a product of the mill’s timber supply. He said the southern pine forest is l00% second growth: "The second-growth trees don’t produce a significant amount of heartwood."
He continued: "We choose to lay up all our veneers into plywood. We do not sort for the LVL industry. Our veneer is 18-22% high grade; we can make more money selling plywood than veneer. While LVL can offer some significant advantages in a poor market, in a medium or strong market we’re better off. With LVL we would be giving up our best veneer."
An 18-door Coe jet dryer with Accumatic vacuum feed and a 14-bin Coe stacker were part of the new installation. Martin also rebuilt one of the Raute jet dryers.
Five Raimann patchers work 12 hours a day, seven days a week, producing about 50,000 faces weekly. Patched veneer off-bears to a circular sorter.
The glue technician mixes for both the spray line and the foam line without touching a bag; the whole mixing process is controlled by weight.
A new Spar-Tek seven-ply foam lay-up line, with four feed stations and three core stations, takes CD veneer and lays it up into industrial and sheathing grade to feed a Spar-Tek pre-press and a fast-closing Spar-Tek 50-opening 4x8ft hot press. For five-ply, pressing time is 5.5 to 6 minutes at 315ºF (157oC). Pressure of 200psi is applied for 120 to 180 seconds, after which the press goes to position control.
The press frame is built with two vertical end frames which are keyed and bolted to matching machined faces on the cylinder base and press crown. This produces a solid structure which maintains its integrity with no movement during a press cycle.
Another feature to simplify maintenance is an adjustable platen guide system with replaceable brass wear strips attached to the end frames, which can be adjusted for wear or replaced without disassembly.
The mill already had two Raute 50-opening presses, bringing the total to 150 openings.
About half the panels are trimmed by the Globe saw line, strapped, and go directly to distribution channels while the balance goes to the finishing department – to two Globe routing and filling lines and then to either a six-head Kimwood sander and a five-in line Globe, or to a Kimwood two-head sander and a speciality saw.
A Samuels automatic strapper serves all the lines.
The output is shipped 60% by rail and 40% by truck with Midwest, Southeast and California the major markets.
The production is a full range of speciality sanded, 1’4in to 11’8in, textured siding, AA, AB, BB, BC and industrial siding.
One speciality is beaded interior panels, pre-sanded and ready to paint. Premium 303 exterior siding is produced in rough-sawn or scratch-sanded face.