IMM Focus: Automotive:Hybrid mold speeds bumper to market

Originally conceived for making bumper prototypes, SPG Group’s aluminum-in-steel Pre-Tension Tool is meeting the demand for short-series, high-quality bumpers and helping carmakers cut time to market for custom or special models.

When SPG Group conceived of a mold using a steel frame and aluminum cores and cavities to make car bumpers, the primary objective was to speed delivery of prototypes to its automotive OEM and Tier One supplier customers. It worked, and production-quality bumpers are being turned around in as little as eight weeks. But prototype bumpers were not the only target market. The steel-aluminum hybrid mold can turn out bumpers in quantities significantly larger than normal prototype batch sizes, up to 50,000 parts, and perhaps a bit more. This opens a door into the market for short-series production models, a market segment that SPG Group sales director Mario Neijts says is healthy and growing.

The reason that bumpers coming from the Pre-Tension Tool, as the hybrid is called, are of production quality is that SPG uses the same technologies it employs to make its production-series bumper molds. The steel frame, which is pretensioned using large, adjustable bolts, provides the stability to neutralize stresses—particularly the lateral forces—that can distort unsupported aluminum in a mold of this size.

Fast Tools, Unique Parts

Neijts says the phenomenon of “mass customization” visible in many industries is a strong trend in the auto business. Auto marketers want buyers to be able to choose a car that is distinguishable from the one next door and that projects an image fitting the driver’s lifestyle. Designers are therefore creating variations of models to personalize them for buyers. The design customization involves the vehicle’s interior and exterior, including bumpers, and the production runs are much smaller than for standard models.

Neijts notes that SPG Group is not competing with its traditional customers, especially the Tier Ones, by molding these limited-run bumpers. The large suppliers are well aware that they are not set up for short runs. In fact, they are already outsourcing this short-run work to SPG. The Pre-Tension Mold went into production at SPG in 2003 and already has some happy clients. Using the new technology, SPG delivered a small series of production-quality bumpers to Porsche that enabled the automaker to start production of a vehicle 10 weeks earlier than originally planned, accelerating its return on investment. A front bumper system for the VW Golf GTI involving 14 components was turned around in nine weeks.

In addition to short runs of 20,000 or 30,000 bumpers for large OEMs and Tier Ones, Neijts says SPG is also looking at automakers whose production runs are always short—for example, Lotus and Ferrari. As well, the ability to economically and rapidly produce up to 50,000 large parts at production-quality levels can extend beyond bumpers. Neijts mentions auto dashboards, since designers want to customize interiors as much as exteriors, and there are also applications beyond the automotive market.

Small-series, Single-source Supplier

To provide an even broader range of service, SPG has created a business unit—SPG Project Management—that enables OEMs and systems suppliers to outsource their small-series part production. SPG Project Management takes on the entire task on a turnkey basis, handling every aspect of development and production, and giving the client a single point of contact.The tooling division of Netherlands-based SPG Group is a global supplier to the auto market, with bumper molds being only one of its specialties. The nine companies that comprise the SPG Group also supply tooling for semiconductor production, consumer electronics, heavy machinery, computers, and more. Specialties include large tools and multimaterial/multicolor molds, and there is full design capability to support clients and contribute to rapid turnaround times. The SPG Group is part of the worldwide Kroymans Group, which employs 2900 and had 2002 gross sales of e1.1 billion ($1.38 billion).