Durakon Industries, a tier one and tier two supplier to automobile and truck manufacturers, is widely known for pioneering the production of truck bedliners. By adhering to a philosophy of "Winning with Technology," the Lapeer, MI-based company says it became the world's largest supplier of pickup truck bedliners to OEMs and the truck aftermarket in 1996.

In the past, the company used manual trimmers in the manufacturing process. As the market for bedliners increased, Durakon officials sought faster, more consistent methods to trim bedliners and other plastic automotive accessories. Though the company provided quality parts at a competitive price in the past, John Montagna, manager of manufacturing engineering for Durakon, said he knew that robotic automation would allow the company to grow.

In June 1994, the company purchased six K30 robots from Motoman Inc. to trim and cut 150 different bedliners from thermoformed plastic sheets. "With the robots, we can guarantee better quality," said Montagna. "The repetitive motion of the robot allows for a more consistent product which has generated more business for Durakon."

The Process
There are three major steps to manufacturing bedliners and similar parts at Durakon's Lapeer site --- extrusion, thermal forming and trimming. The raw, high-density polyethylene material is first extruded into sheets of 70 to 80 inches by 110 to 120 inches, in thicknesses of 1Ú8 to 3Ú8 inch. A forklift then loads 30 to 100 extruded sheets onto the loading platform of the thermal forming machine. This machine consists of four stations: a sheet load and positioning station, a heating station, a molding station and a part transfer station.

A sheet is locked into position before moving into an oven, where the sheet is heated to 400F. This softens the material into a bag shape for forming. Next, the heated sheet is placed into the mold station, where lower temperatures and a vacuum are applied. The vacuum draws the sheet against the mold to form the pickup truck bedliner shape. After the part is formed and the vacuum is removed, the part is cooled further before trimming. The square-like bedliner forms are then moved by conveyor into the trimming area.

The trimming area is made up of a trim cell, where parts are trimmed by Motoman robots. The thermoformed shell is secured with a set of fixtures and mechanical clamps. The robots first cut holes to allow attachment of bedliners to truck beds. Then, while one robot trims the bedliner perimeter, the other robot trims the tailgate section. The robots follow a pre-determined path around the tailgate or bedliner and complete trimming in less than five minutes. To extract the bedliner from the molded plastic, 40 linear feet of perimeter is trimmed and up to 10 holes are cut.

Improving Productivity/Quality
The trimming operation is now operated three shifts per day, five days a week. The number of bedliners produced and new products developed have grown with the use of robots. "Our production has increased since installing the robots," said Montagna. "We are also using the robots to trim interior door panels for vans at this location. This is a new product that could not have been produced without robots because the tolerances required are tight."

To overcome the limitations of the manual trimming process, Durakon selected the robots, equipped with routers and cutting bits, to perform the trimming function. With six-axis movement, the robots have much better control over such variables as pressure, cutting speed, and tool angle, Montagna said.

The cutting paths are preprogrammed for every type of bedliner. Once the bedliner number is entered into the robot controller, the robot automatically trims according to the specific program. After cutting, the scrap is melted and reused.

The MRC controller, with 32-bit Reduced Instruction Set Computing (RISC) architecture, directs the robot and includes menu-driven, application-specific software environment and easy-to-use program functions. Digital servo drives and digital signal processors ensure high-speed performance and high-path accuracy.

According to Montagna, robotic technology has significantly improved productivity. "Output at the automated cells has increased dramatically," said Montagna. "Quality has also definitely improved."

Increased Business
Montagna said he believes the robots' improved trimming consistency is strengthening the company's opportunity for contracts with OEMs in both domestic and international markets. This new quality status is already having an impact. Durakon was certified as a QS-9000 manufacturer in 1996. In January 1997, Durakon was named the exclusive supplier of pickup truck bedliners to the Ford Motor Co. for pickup trucks sold in the United States and Canada.

The robots are also helping Durakon expand into new markets, Montagna said. More new products are expected in the future as Durakon further expands into the accessories market for sport utility vehicles, vans and passenger cars. "Automation means you are going to remain strong and competitive, which enables us to garner more business. We are also able to guarantee better quality with the robots -- if you can deliver that, more business will follow."

Plastics Machining & Fabricating
P: (847) 634-4347 F: (847) 634-4379 EMAIL: hfrankurba@aol.com	P.O. BOX 1400 LINCOLNSHIRE ILLINOIS 60069