MOLDMAKING REPORT: Cost and weight reduction solution earns high praise for Waltec Engineering

The story of this SPE award-winning part began in January 2000 when Michael Pickholz, manager advanced exterior project development from LDM Technologies (Leamington, ON), approached Waltec Engineering Inc. (Wallaceburg, ON) about producing a mold for a controlled energy management (CEM) part. Pickholz knew this particular mold would require a high level of tooling experience, and Waltec’s reputation and previous successes for Pickholz made Waltec his first choice.

The new part was to be a component bumper energy absorber that LDM was producing for the Ford Windstar. Discussions were also held with General Motors and Chrysler, who expressed interest in the part concept and process. The first development review meeting with Waltec and LDM was held in February, and by April Waltec had released the prototype tools.

General Motors was so intrigued they placed an order with LDM to produce the part for the Cadillac STS, and LDM kicked off the production mold just two weeks after the Ford prototype mold was produced. The first Cadillac STS samples off the production mold were a first-shot success.

“In October of 2000, I submitted a prototype build of a Ford Windstar CEM to SPE as an entrant in the annual plastic design competition,” says Pickholz, “and in November we were notified that we had won first prize for the Chassis Division, and the grand prize for Innovation. We share this win with Waltec and all members of the build team.”

The real story is the innovation that went into this part and its mold. As the photo shows, the part is a honeycomb of small plastic tubes. The honeycomb fits inside the bumper shell and will crush during an accident. Traditionally, bumper innards were either foam or mechanical.

The mold has 123 hot drops and 140 individual temperature zones, which gives the molder great flexibility to program the parameters for optimal molding. The mold is designed to maintain the part’s wall thickness at +/- 0.002 in.

This honeycomb solution meets all crash test requirements, reduces bumper weight by two to eight pounds, and saves $7 to $12 per vehicle over other energy management products. In this way, auto makers can use smaller isolator packages that reduce rear overhang and save $2 on each vehicle.

Waltec is ISO 9001 certified, and compliant with QS-9000 and TE Supplement. The company designs and builds plastic injection molds, die cast dies and forging dies for clients in the automotive, power tool, plumbing and consumer goods industries.