High-speed chop line increases yield

High volume and high yield help component producer Cox Interior offer faster turnaround times. And a new high-volume chop line has streamlined operations and helped to achieve both.

 

"We average 150,000 lineal feet through this line in a 400-minute work day," says Cox's Tim Graham.

 

And the amount of waste material has been cut from 17 percent on the old line to 9 percent on the new line.

 

Weinig Group supplied most of the line, including three GreCon Dimter 450 high production chop saws, new technology LuxScan scanners, and most of the conveyors and handling equipment. Cox personnel built the scrap conveyors.

 

Cox Interior's 880 employees make interior and exterior doors, stairways, circle stairways, treads, balusters, risers, also cabinet door panels, mantles, keystones and arches, all in a large plant in Campbellsville, Ky. Graham says that stain grade veneered arches are an important product line, and Cox can make these in oak, cherry, mahogany and walnut. Cox supplies 25 hardwood species, primarily poplar, red and white oak. Cox runs a mix of No. 2 common, No. 1 common and 1F.

 

Infeed and scanner

The new line started running in February, replacing a 10-chop line that had a backrip system, and was running two shifts.

 

The operator's responsibilities are limited on the new line. First, boards are loaded on the infeed table. The operator keeps the boards straight, keeps them in queue, doesn't let them overlap, and positions sharp pointed boards. The operator also sets up the cutting widths for the product being run.

 

Cox Interior is running 60 boards a minute. The LuxScan scanner can process any board from 6 to 16 feet in length, and 1-3/4 to 7-9/16 inches in width.

 

"The wider the width you have the more resolutions to the cut, so you have to run it at a slightly lower pace," Graham says. "It takes the software just a little more time to figure it out."

 

After the scanner, boards go to three GreCon Dimter 450 high production chop saws. Material is then sent by conveyor and sorted as in a rough mill, by scrap, by rerip, cut stop length, orders received, and lengths from 6 to 24 inches.

 

Longer material is used for moulding. Shorter material that can be used for fingerjointing is sorted by width and thickness and placed in large blue bins. Shorter lengths are put on a conveyor that leads to a large box. Graham estimates that 90 percent of what Cox does is fingerjointed.

 

A long conveyor leads to a circular table, which is for rerip.

 

"We try to salvage every inch of the board we can, in length or in width," Graham says.

 

Cox was cutting 5-1/2-inch wide material during a recent visit. "We'll backrip that, in other words we'll rip it down if it has a bad edge on it, down to a 4-1/2, 3-3/4, 3-1/2 inch or less, even down to 1-3/4 inches.

 

Increasing yield

Pieces that have already gone through the chop saw are processed in this way to get more yield.

 

On a 5-1/2 inch board, for example, if that knot appears right in the middle, and good material could be produced on either side of that knot, the software determines how to backrip this board, cut out the knot, and salvage the 4-1/2-inch piece.

 

Graham says the technology of the scanner has jumped forward two-fold, compared to its first scanner, which was used for four years.

 

There are eight people working in the current operation. Previously, it took 15 to do the same work on two shifts.

 

"When we took out our old chop saw line and put the new production line in, we went from two truck trailerloads of waste a day to one," Graham says.

 

"Also, this production line is fast enough now that it allows me to maximize the fingerjoint operation. I can keep longer runs in front of them, which keeps them efficient."

 

Graham says that the cost of the new system was questioned, but after about five weeks, the improved efficiency and yield of the crosscut system was obvious.

 

Rough mill

Cox Interior's rough mill feeds material into the crosscut line. The crosscut line in turn feeds the fingerjoint operation, door factory, moulding operation, or gluing. In this plant mouldings are primed but not finished.

 

Other equipment includes a new Weinig 500 PowerLock quick-change moulder that allows Cox to do many setups in a day, three Kval door machines, and a Northwood CNC machine. Cox is also looking at putting another scan rip line in.

 

Graham says that Cox does mouldings particularly well. That requires good machines, quick setup, and an excellent grinding room for tooling.

 

Cox Interior sells directly to the homeowner or the contractor that's building the house. Customers can order a package from Cox that includes architectural millwork and veneer pieces in the same species. Graham says this direct link with the customer is a special service Cox offers.

 

Graham hasn't seen too much competition from imports, which may require six to eight weeks delivery time. Cox Interior delivers in a week or two.

 

"You can call us and ask for a 20-foot piece of Brazilian cherry handrail, and we're probably going to have it to you in a week," he says.

 

Someone building a new house could get a complete package of trim in two to three weeks.

 

"We strive on service, and quick delivery," he says.

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About the author
Karl Forth

Karl D. Forth is online editor for CCI Media. He also writes news and feature stories in FDMC Magazine, in addition to newsletters and custom publishing projects. He is also involved in event organization, and compiles the annual FDM 300 list of industry leaders. He can be reached at [email protected].