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New Technology Benefits Oregon Mill
Roseburg Forest Products Pioneers System from Wagner Electronics to Measure Green Density
By Carolee Anita Boyles
Date Posted: 7/1/2006
ROSEBURG, Oregon — It takes a large dose of intestinal fortitude to be the first to implement any new technology. Roseburg Forest Products has taken a leap of faith and invested in a new technology to sort green lumber for drying. If Roseburg’s innovation pays off, it will lead to both energy savings and improved product quality.
Founded in 1936 by Kenneth Ford, Roseburg Forest Products began as a one-mill operation just east of Roseburg, Oregon. Through careful and judicious purchasing of timberland and by pouring profits back into the business, Kenneth built Roseburg into what it is today a totally integrated, state-of-the-art company whose business begins in the woods and ends in the boardroom.
“We have four plywood plants, two particleboard plants, an engineered wood products (EWP) plant, and a chip facility at Coos Bay in addition to our stud mill just outside Roseburg in Dillard, Oregon,” said Dave Reader, quality assurance supervisor and planer general foreman of Roseburg Forest Products. Other than a particleboard mill in Missoula, Montana and a plywood plant in Weed, California, the rest of the company’s mills are in Oregon.
At the stud mill outside Roseburg, the company cuts lumber that ranges in length from 6 to 10 feet. “We cut 2x4s, 4x4s, 2x6s and 4x6s, and 1-inch as a falldown,” Dave said. “That’s our entire product line
Roseburg Forest Products has not grown and succeeded by avoiding risk. Rather it has a history of thoroughly evaluating new technologies and taking carefully calculated risks that have enabled Roseburg Forest Products to ride the wave of the country’s dynamic housing market.
At the Dillard mill, Roseburg Forest Products has done a lot of high tech innovation over the past few years. “We have scanners on all the breakdown equipment and the debarker,” Dave said. “So the log is scanned when it comes in, and the equipment can tell how to buck it up. We have scanners on both head rigs, all four edgers, and both trimmers in the mill. Inside the sawmill we have a real-time size check system that has eight different sites, so every board that goes through the mill is measured about 250 times.”
At the planer, a machine performs geometric grading and looks for biological defects, running about 220 boards a minute.
“We have a batch trimmer that runs at about 240 boards a minute,” Dave said. “Everything is automated. We have one person working as a grader who looks for things that the machine doesn’t ‘see’ well. The end seal and the stencils are all automated as well.”
The mill cuts about 70% Douglas fir and also hemlock, white fir and lodgepole pine. The lumber is sold dry or green, depending on market demands. “All the hemlock, white fir, and lodgepole pine goes out dry,” said Dave.
The timber that comes in for cutting is from a mixture of private land and what the company buys from other sources.
The studs cut at the mill go to both big box stores and a network of wholesale customers. “We don’t sell to small customers,” Dave said. “We want customers who take truckloads and truckloads at a time. Big box stores make up roughly 20 percent of our customer base, and distributors and warehouses make up the rest.”
All in all, Dave said, the Dillard mill cuts more than 400 million board feet a year. “There are some random length mills that do more than we do under one roof,” Reader said, “but I believe that makes this the largest stud mill in the world.”
“Roseburg Forest Products, like many other lumber producers, was looking for a good way to sort green lumber prior to being stacked for drying,” Dave said. “As we all know, there’s a very large difference in the amount of moisture in different pieces of lumber; thus, different pieces require a different amount of time to dry to perfection. If lumber can be sorted into groups that require close to the same amount of drying time, it would save drying time — saving energy and improving kiln capacity while also improving recovery through less shrinkage and warp from over-dried lumber.”
At a trade show in Portland in 2004, one of the things on Dave’s list to look for was a way of sorting green lumber for drying. He saw a demonstration for a new product called a density sorter that was being manufactured by ISOSCAN (formerly Trueview), a company in Australia. The evening prior, Wagner Electronics had reached an agreement to be Trueview’s exclusive sales representative in North America.
“After the product demonstration, I met with Wagner Electronics and ISOSCAN representatives,” Dave said. “They claimed that this system was working very well in Australia and New Zealand, and that it was cutting 15% off drying times and improving recoveries significantly.”
That intrigued Dave, but he wanted to see the equipment in action. Dave and two other Roseburg Forest Products representatives flew to Australia to see the density sorter — called the LDS 200 — in action.
“We looked at three different mills, seeing the density sorter at all three mills,” said Dave. “We heard nothing but rave reviews from the mill operators and observed it operating flawlessly on radiata pine at speeds of up to 120 lugs per minute.”
After about nine months of negotiation, Roseburg Forest Products became one of the first two forest products companies in North America to install an LDS 200. (The other LDS200 is operating at a company in Florida.)
To understand the value of the LDS 200 in a mill operation, it’s necessary to understand something about what the system is and how it works.
“The LDS 200 was designed by the Institute of Geological and Nuclear Sciences, Ltd. — GNS — in New Zealand,” said Ron Smith, senior applications and technical advisor for Wagner Electronics. “This system was first marketed and sold in New Zealand and Australia. It uses very low-level gamma rays that are very safe and environmentally sound — you get more radiation flying cross-country in a jet aircraft.”
The very low-level gamma rays are harnessed to measure the green density of the lumber. Once the green density is determined, accurate predictions can be made about the rate at which the lumber will dry.
“That’s where the rubber meets the road,” Ron said. “The green density is defined as a combination of the amount of water in the piece of lumber and the density of the cellulose itself.” The density of the cellulose varies among species of wood and even between different pieces of wood of the same species.
There is a very strong correlation between the green density of wood and how fast it dries. “Wood with a higher green density dries slower, and wood with a lower green density dries faster,” Ron said.
Why is this important?
“When wood is in the sawmill, it’s already being automatically measured and sorted by width, length, and it’s going into different bins,” Ron noted. “A given sawmill might have 20, 30, 50 or even more bins, depending on the number of products cut at that mill. Let’s say a high percentage of the volume of this mill is 2x4s of 8 feet, 9 feet, and 10 feet, a combination of hemlock and fir. If a mill has the bin capacity, or can make bins available, they can double up how they’re sorting the lumber and not only sort it by size, but also sort it by green density, putting the ‘heavy’ wood in one bin and the ‘light’ wood into another bin.”
Now, instead of one bin for 2x4s, there is one bin for 2x4 ‘heavies’ and one bin for 2x4 ‘lights.’ This allows the mill to segregate and dry lumber with similar green density.
“If you can decrease your drying variables going into the kiln, you’ll decrease your variability coming out of the kiln,” Ron said. “When you sort your ‘heavies’ into one group, you can dry them on one schedule. And you can dry your ‘light’ sort in a significantly shorter amount of time than if you were drying both types mixed.”
Having the capability to measure green density and sort by green density for drying provides a lot of benefits. First, it means a more consistent product at the end of the drying process. The drying
Second, the company benefits from energy savings. It can produce kiln-dried lumber, achieving a more consistent product, in a shorter period of time. “It means a huge potential energy savings,” Ron said.
Another benefit is increased production. “In the long run,” Ron added, “your actual energy consumption may not go down all that much. Your total energy consumption may actually be the same because you’re still keeping the kiln busy. But at the same time, you have a higher annual throughput. You’re drying more lumber for the same amount of energy in the same amount of time.”
Roseburg Forest Products installed two LDS 200 systems at the Dillard stud mill on the weekend of July 4th, 2005.
“We put a density sort system on each of our two sorter lines,” Dave said. “Line one runs a top speed of 120 lugs per minute with 32 inches between lugs. Line two runs up to 165 lugs per minute with 16 inches between lugs. The installation of both lines took 48 hours and went in very well. Start-up cost us no downtime, but it did take us a few days to ‘tune’ for sorting purposes.”
Before the LDS 200 systems were installed, technicians were concerned about the speed of line no. 2, and the line did have some ‘bugs’ in it.
“We’ve had the system ‘lock up’ on line two,” Dave said. “It seemed to be a computer software problem. Their software didn’t seem to want to keep up with the speeds that we run. We now run between 140 and 160 lugs per minute with few lock-ups, and that problem is 95 percent fixed or better.”
Another challenge Roseburg Forest Products faced was mis-marking and-or improper placement of lumber once it was sorted.
“Our sorter is very large, and at times the reloader operators have put the wrong tag on a unit, and at times the drivers have stacked a sinker unit in a floater crib,” Dave said. “Communication and education have been the main tools to fix this problem. We have also ordered an ink jet marker to go right behind the density sort so it will mark all the sinker and floater with their own mark. So in the near future, each board will be clearly marked.”
Overall, Dave said Roseburg Forest Products has been very happy with the results it has had with the LDS 200.
“We’ve seen a 15 percent reduction in the time and energy needed to dry lumber,” he said. “Those are both big things, because the energy reduction is a straight cost savings, and the time is capacity. That’s important to us, because this year we’re drying a little more than 50 percent of our total product, and drying that much really pushed our capacity. If we didn’t have the density sorter in place, we couldn’t dry as much as we’re drying this year.”
The money Roseburg Forest Products saved on energy is not inconsiderable, but it’s still not the biggest change the company has seen at the stud mill as a result of installing the LDS 200 systems.
“By separating the wood into density sorts, we’re able to dry it better, so we don’t over-dry wood as much,” Dave said. “That saves us from a huge amount of degrade lumber. The biggest cost for a sawmill is the cost of the log — the raw material — itself. If you damage the raw material, there’s no way you’re going to win that fight. So by reclaiming more of the raw material into a usable product, we’re able to save a lot of money. We saw a big savings in both grade recovery and in trim loss.”
Where does Roseburg Forest Products go from here?“We just keep looking for new things,” Dave said. “We’ve been real happy with the LDS density sorter. It’s done what we’ve expected it to do.”
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