Scanning for lumber grade and defects is still a young technology. Most companies considering the technology spend months or years researching it. Tim Kelly, vice president of Kelly Lumber Co., made the decision in a couple of weeks.
It could be said necessity was the mother of invention. A fire destroyed Kelly Lumber Co.'s newly built flooring mill in February 2004, so the company needed to rebuild the mill quickly. To achieve the throughput rates he was looking for required a chop saw coupled with automated scanning. So he called WoodEye and asked for a quote to integrate its scanning system into his mill. The new mill was up and running in January 2005.
Prior to the fire, the Ashland, Maine-based company was using a rip-first system with an automatic chop saw. Employees were manually defecting with crayons. Kelly saw getting away from manual grading and defecting as a big step forward.
Eliminating manual grading has three benefits, according to Kelly. It increases consistency because the scanner grades the same every day. It cuts direct labor by eliminating the bodies doing the manual scanning. And it eliminates a major human resources headache.
"The people doing the grading and defecting are the second-highest paid in the mill. They require very high training costs and they have the highest rate of turnover in the plant," says Kelly. Combine those three factors, and you have an enormous labor cost in defecting and grading.
Kelly figured his payback on the automated scanner at 16 months in labor savings alone. That doesn't factor in any benefit from increased yield, better quality and consistency or improved productivity. That's all icing on the cake.
Kelly Lumber's flooring plant is producing what Kelly calls "boutique" flooring. The primary species is hard maple, and the company produces "wider widths, longer lengths and smaller bevels," according to Kelly. He says they aren't trying to compete in the commodity oak flooring business. The company wants to fill the need for upper-end flooring in the better distributors.
The mill has the capacity to do 12,000 square feet of flooring a day, with about 22 people when it's running at full capacity. Kelly describes that as a "nice, even 12,000 feet a day, all at the high end of the flooring market."
The process starts with rough 2 and 3A common lumber, either purchased dried or dried in the company's six Irvington-Moore dry kilns. Lumber is first run through a Cantek double-sided planer. Kelly says the double surfacing is done simply to give the scanner a better surface to look at. The WoodEye system could scan the rough lumber, but results are better with the surfaced lumber.
From the planer, boards move to an infeed table for a Paul optimizer. Kelly says the Paul optimizer uses triangulating lasers to determine size and the shape of the top of the board. It can account for wane on top of the board, and will skew boards sideways if it has to. The Paul optimizer feeds a Progressive 30-inch fixed-arbor rip saw.
"We use standard sizes so fixed-arbor works very well and gives multiple combinations to optimize yield," says Kelly. After the rip saw, waste is separated manually and ripped boards are fed into the WoodEye scanner. The scanner grades and defects the boards at a maximum of 1,200 feet per minute and feeds a Dimter 450 Quantum chop saw. Pieces come out of the chop saw and are automatically sorted and kicked into the proper areas. From there they are sorted manually and palletized.
That sounds simple, but getting all that to happen at 1,200 fpm is a trick. The key is the WoodEye scanner and its software. Kelly says it integrates seamlessly with the Dimter chop saw.
As the board starts coming in to the scanner, both the scanner and chop saw see the board coming and start measuring the length of board. The chop saw also measures the board's width to set the fence. The scanner measures the board two ways using physical encoders and optically.
The WoodEye scanner uses color scanning technology to create a color image of all four sides of the board. The WoodEye software then uses that information to match the board with the cutting bill for the day, fitting the board into the correct lengths and grades needed. The cutting information for each board is then sent to the saw.
Scanner in control
The saw simply follows the WoodEye's instructions. "The chop saw is a simple saw," says Kelly. "Dimter makes more complex ones that read crayon marks and cut around them, but this one follows the scanner's directions. It counts rotations on the infeed encoder, stops, cuts, counts, stops, cuts."
The chop saw measures the length of board again as it comes into the saw. Kelly says that makes sure it is cutting the board that was scanned. "Every now and then something will get out of sequence or a board will fall on the floor," says Kelly. "The chop saw sees the wrong length and stops."
Kelly's system has a lateral infeed table between the scanner and chop saw that serves as a buffer. Kelly says that on newer systems they are eliminating that buffer and its added complexity and chance for error. "With the speed of the scanner and chop saw, you could run right from the scanner and into the saw," he says. "If you are scanning faster than the saw, then add a second saw and have it run to both saws. Then if one saw jams, everything goes to other saw." Kelly says that's the route he can take if the company needs to add capacity to the system.
Kelly says the two companies WoodEye and Dimter have integrated the two seamlessly. "You hear these stories about two companies fighting over where problems are, but we haven't had that happen. The data interchange is transparent between the two and we haven't had problems with communication between them."
Training the scanner
Startup of the mechanical system took about three weeks and went without a hitch, says Kelly. Getting the scanner and software calibrated took a little longer. "We went to WoodEye's headquarters in Sweden with 20 boards and thought we had trained the software there," says Kelly. But he discovered fine-tuning the software to read the real-world variety of boards is a time-consuming task. "It took us two solid weeks back here to train it for just for color on one species."
The results have been more than worth the effort. Kelly says the color scanning ability of the system is phenomenal. "We can say if we want dark or light maple and the scanner will pick that up and optimize accordingly. The results are amazing."
In addition to the improved, labor-free grading, the WoodEye software opens up some entirely new abilities that are allowing Kelly Lumber to move into the component business. "Right now our main business is flooring," says Kelly. "We are moving into components, and if that's all I was doing, I could make 70,000 a day."
That's 70,000 blanks that are optimized and labeled. As parts come out of the chop saw, a part number is inkjet printed on each one. In addition to a part number, the software can find parts in the rough lumber.
An example Kelly uses is a chair arm. He says he can start with a simple bitmap outline of the part and add the proper dimensions. He can also give the part very specific characteristics according to grade.
"Say it's a chair arm, so the first four inches have to be clear, then the next six inches can be 2A, then go back to 1A. The software will find parts that meet that specification on the fly, cut them on the saw and label them right down to orientation for the next machine."
The right face
For the flooring product, the scanner determines the good face for each part as it goes through and a black dot is applied with an inkjet printer on the back of the part. Parts are then manually sorted and palletized, then moved to the next building for storage prior to being milled for flooring.
The flooring line is in an adjacent building and consists of a Leadermac six-head jointed moulder, a Doucet end matcher, and material handling and packing equipment. The blanks are run through the moulder and either palletized to go to an off-site finishing contractor or packaged for sale as unfinished flooring.
"The flooring business has been very tough for a lot of people the last couple years, due to overcapacity," says Kelly. "People wonder why we're getting into it right now, but I think it's a great move for us. With the capabilities we have, we can fill the gaps in the market."
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