"In this business, you must be fast on your feet," says Bruce Wakefield, manu-facturing engineer for Mann+Hummel Automotive. The South Bend, IN-based company develops and produces injection-molded plastic manifolds for the international automobile industry. Using lost-core and multi-shell technology, the Mann+Hummel unit is a Tier One producer of plastic manifolds, primarily for U.S. OEM customers.
The plastic manifold segment of Mann+Hummel business has been highly successful for the past 10-plus years. Injection-molded plastic manifolds are both lighter in weight and lower in cost than cast-metal versions. They require neither honing nor polishing, and permit more complex geometries than cast metal manifolds, improving airflow. Plastic manifold components are friction-welded on the production line, eliminating the need for later assembly on the vehicle engine-production line.
The South Bend operation produces three-part manifolds for four-cylinder General Motors engines, and a four-part assembly for eight-cylinder Chrysler engines. As with most auto-parts manu-facturing facilities, the Mann+Hummel manifold plant requires both efficiency and flexibility. "We have major investments in production equipment and stringent delivery requirements for finished products," says Wakefield. "To ensure that we can meet our primary commitments, we may have excess production capacity that we can sell. At the same time, we must avoid downtime, which requires being able to service our production lines quickly, including necessary reconfigurations and repairs."
Manifold production lines include conveyors that feed three 1,750-ton presses located in three cells. Work in process goes from the presses to a collect chute, where operators put parts in totes and continue on to workstations where automatic welding takes place.
The original conveyor system, installed when the plant was built in 1989, was a typical fixed steel design, with runs varying up to 80 ft. Though the conveyors performed reliably, there were circumstances when they did not offer the flexibility or ability to "tweak" a configuration that would have helped production flow. When manifold designs changed, the molding cells needed to be reconfigured. In some cases, this meant ordering new conveyors, which meant waiting weeks for them to be delivered.
In early 2000, Mann+Hummel replaced the conventional steel conveyors on a secondary line in its South Bend plant with a lightweight, modular plastic conveyor system made by Dynamic Conveyor Corp., Muskegon, MI. The trial DynaCon system proved reliable and offered flexibility with a range of module designs. The company decided to apply the system to the line feeding one of its primary manifold-molding cells.
"We had a tight arrangement in one cell, and the DynaCon system made it a lot easier to bring the parts in on the conveyor," says Wakefield. "We were able to try angles on the conveyor as we were laying out the cell on paper. It gave us flexibility in our floor plan and for down the road if we want to make changes. And it's easy to reconfigure the conveyor. That's an advantage, because with automotive programs, your cell will eventually be obsolete."
Wakefield says the assistance he received from Dynamic Conveyor during installation made it virtually turnkey. He adds that modification is easy, thanks to the extensive inventory of standard parts he maintains. "The last metal conveyor we ordered took five or six weeks for delivery," he says. "With the DynaCon system, we can work with the modules and components we have on hand."
Wakefield says the remaining, fixed conveyor systems at the plant will eventually be replaced with modular DynaCon systems. "Many manu-facturers who use conveyors would benefit from this system," he says, "especially from the perspective of the commonality of parts throughout the entire production line."
