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July Aug 2003

Going radical with Red Cedar

Canadian forest company Interfor has established a new western red cedar reman mill in the US using some radical new concepts.

By Alan Froome

When you look at lumber products as a whole, western red cedar stands out as a special case. It is highly valued for use as fencing, decking, siding and numerous outdoor uses as a result of its natural weather-beating properties. In Canada, however, it basically only grows in the coastal regions of BC. While there are many established cedar mills on the west coast of Canada and the US, a new cedar mill—recently relocated for economic reasons— is taking another approach to the business and adopting some radical new concepts.

Carlo Rodrigues, manager of the CedarPrime mill, with a load of low grade cedar that will be remanufactured at the new US facility.

Canadian company International Forest Products, or Interfor, realized some time ago that the lumber they were producing at their McDonald Cedar division in Fort Langley, BC, was only marginally cost effective. They started to look at the possibility of relocating to the US side of the border. Possibility became reality when the US countervail/duty of 27.2 per cent, which also applies to cedar, was imposed on softwood lumber going into the US. A decision was made to close the mill and move south.

The entire move took only four months, from shutdown in BC to start-up this past February at the new location. Much of the machinery used in the new mill was from the old McDonald Cedar mill, but it is being used in a new way. The new company is called CedarPrime Inc, a brand name Interfor already has in the market. Sumas, Washington, where the mill is located, lies just south of the BC border. As a somewhat depressed area for jobs, the town was helpful in many ways in establishing the new facility.

An existing dry kiln company, Socco Forest Products, was interested in leasing acreage to the new company and providing kiln capacity. Setting up the new mill presented an opportunity to change production methods. The plan called for shipping low-grade cedar across the border from Canada and remanufacturing it to higher value products in the new US-based mill. Jack Draper, vice-president of Interfor (Cedar Division), estimates that the new Sumas mill represents a saving of $5 million CDN a year on duty alone, as the BC mill now ships low value lumber into the US, instead of high value. “The success of our US mill and its critical cost advantage is important to the survival of all our mills as a group,” he says. Overall design and engineering of the new mill was entrusted to Ches Piercy, a sawmill consulting engineer based in Qualicum Beach, BC.

The Addvantage X-ray scanner processing green common cedar. It scans the lumber for defects, looks for clears and controls the two downstream Dimter 304 Opticut chop saws.

Lloyd Pederson of Kelowna, BC was also involved for project management. After many meetings between Piercy and the Interfor engineers, it was decided the new mill would have three lines—basically a chop line, a finger-jointing line and a molding line. A six-acre site, with building, was leased from Socco FP to build the new mill. “It was a challenge to fit everything into an existing 40,000-square-foot building Socco already had on site, but it saved us a lot of time,” Piercy says. The pressure was on to be up and running as fast as possible.

Despite this, some radical new concepts were planned, some of them unique in the remanufacturing business For example, they now use low-grade green common and shop grade cedar, in lengths as long as 20 feet, to feed the mill, supplied from Interfor‘s Canadian mills, principally Hammond, BC. They also x-ray scan for clear lumber before finger jointing the blocks and gluing the blocks green (undried), and dry them after finger jointing and gluing. As well, the finger-jointed boards are now moulded and resawn to make bevel siding for other products after kiln drying.

The Dimter 304 Opticut chop saws (above) after the scanner. Lumber on the chop saw line is mostly 2x6 and 2x8.

The mill is part of a unique three-way partnership with neighbours Socco FP, who dry the lumber, and the Sumas 1 co-generating plant, also next door. The co-gen plant provides steam to the kilns and disposes of the sawdust from the mill. Wood chips are sent to a pulp mill. One of the members of the design team, Carlos Rodrigues, formerly manager of the Hammond and MacDonald cedar group, was selected as manager of the new mill. Rodrigues is one of a core team of four management and six specialists transferred from Canada to run the mill. As Sumas is close to the border, they actually commute from the BC side each day under a US transferee visa.

In addition, over 60 local people have been hired and trained, with the help of the Bellingham Technical College. The mill’s three basic lines can process random length blocks from 6 inches to 20 feet long. On the chop saw line, the lumber used is mostly 2x6 and 2x8. It is first fed through a Stetson Ross 610 planer to get uniform width and thickness, then on to a transverse lug loader deck, which feeds the Addvantage scanner. This scans the lumber for defects, looks for clears and controls the two downstream Dimter 304 Opticut chop saws. The pieces are then sorted into bins before the next stage. “Any wood with moisture content over 60 per cent at the scanner is kicked out and brought back later after air drying to a lower level,” says Rodrigues.

The green chain and sorted bevel siding at the CedarPrime mill (above). The production target for bevel siding at the mill, which is run on a two-shift basis, is 70,000 board feet a day.

At the finger-jointing operation, clear blocks are conveyed into the Western Pneumatics finger-jointing line, which lightly end-trims the pieces. A 3/8” feather joint is cut at one end and the pieces then move across to allow the other end to be trimmed and the joint cut. From here, the pieces move through the glue applicator and then are manually graded. Any material with knots or other defects is removed. Approximately 40 per cent of the incoming rough cedar becomes waste—due to wane and rot—and because no defects are permitted in the finished products.

The accepted pieces move 90 degrees through into the assembly machine, which presses the glued pieces together, using 400 psi to make the bond. The finger-jointed lengths, up to 20 feet, are transferred past an end trim saw and across a deck, into a horizontal resaw. This can split the boards in two when making bevel siding downstream. These lengths are then stacked and sent by forklift to the kilns for drying. “We had to do a lot of work on the glue before we got it right,” says Rodrigues. They now use a special polyurethane-based glue supplied by Nacan Products of Surrey, BC. “It’s important that there are no air gaps in the joints and that the moisture content of the cedar actually works as a catalyst with the glue.”

A full bond is made within the five minutes it takes to move the glued boards across the transfer table to the horizontal resaw. The integrity and strength of the joints have been tested and approved by forest industry research lab Forintek. The third line at the CedarPrime mill is the moulder, a used Weinig H22B, which was purchased and reconditioned in Germany before it arrived in Sumas. The finger-jointed boards are brought back to the mill after drying down to about 12 per cent and are singulated from a pallet lift onto a transverse deck before feeding into the moulder.

Then the pieces are turned on edge and passed through a Turner 48” vertical band resaw set at an angle. This splits the boards into two bevel pieces, both 1/2” thick, which then go to a green chain for sorting and stacking by hand. The scanning system which controls the two chop lines is key to the entire operation and was supplied by COE Newnes McGehee. The Addvantage chop saw optimizer system is very much state of the art and controls the chop saws to recover the high-value clears. “The system was developed at our Salmon Arm, BC, plant and we have eight systems installed so far,” says Harry Ogloff, COE product manager. “The system is capable of running at feed speeds up to 700 fpm.

The line at Sumas is running at 400 fpm at present.” He notes that the CedarPrime project was very challenging, as is any scanning application on cedar due to the wood’s unique characteristics, such as colour variations and internal rot. For this reason, four separate types of sensor are used at Sumas, providing combined information about the material. Laser profile sensors, top and bottom, scan for shape variations like narrow material or wane. A camera looks for surface defects, like knots, splits and pitch pockets, while an x-ray sensor looks internally for density defects like knots or rot.

Also, a moisture sensor detects wet pockets and allows the green finger-joint blocks to be sorted by moisture content. “The Addvantage system can automatically grade lumber using 600 fixed-length grades, 20 finger-joint grades and 10 backrip grades,” Ogloff explains. “Its ability to optimize the cuts using an assortment of grades sets it apart from manually controlled lines.” CedarPrime is now producing 1/2”x6” and 1/2”x8” bevel siding, both solid and finger jointed. Most of this is shipped east to the Boston area. They also make export clears in 7/4” x 6” and 7/4” x 8” in lengths from 3- to 8-feet, which goes to Australia for use in window frames. Finger-jointed blanks in 2x5s, 2x6s and 2x8s, in lengths mostly 16 feet long, are shipped to a California customer for edge gluing into wide panels.

The mill is run on a two eight-hour shift basis and being new production was still ramping up earlier this year. Production targets are 60,000 board feet a day of finger joint material, 35,000 board feet a day of bevel siding from the molder line, plus additional production in rip blocks and clears, for a total of 20 million board feet a year. Approximately 40 per cent of the incoming rough cedar becomes waste due to wane and rot and because no defects are permitted in the finished products.

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