Tech Briefs
Thermoplastic hardtops

Jeep Wrangler thermoplastic hardtop produced at Husky technical center

Prototype thermoplastic hardtops for the Jeep Wrangler are being made at Husky Injection Molding System's new technical center in Novi, MI. Fifty will be fitted on fleet vehicles, and as many as 5000 thermoplastic hardtops may represent initial production as early as the 2001 model year.

"If customers are as satisfied with the Jeep hardtops as we are and tests go well, we'll move forward with concepts for complete vehicle construction using the new material and molding technologies," Jim Holden, DaimlerChrysler President and Board of Management Member, said during a media event at Husky's new 9290 m² (100,000 ft²) facility.

About 2787 m² (30,000 ft²) in Husky's technical center is leased to DaimlerChrysler. Thermoplastic hardtops are being produced from a dual-platen injection-molding machine that is twice the size of the largest molding machine currently used in the auto industry. At 590 t (650 ton), the new machine exerts 80,000 kN (8,800 US tons) of clamp force, and can inject more than 45 kg (100 lb) of thermoplastic at a time.

Compared to the current sheet molded composite (SMC) Jeep Wrangler hardtop, the prototype hardtop is 10 kg (23 lb) lighter.

In addition to Bolton, Ontario-based Husky Injection Molding Systems, key suppliers on the project include Decoma International of Concord, Ontario (high volume production); Montell USA, Inc., Wilmington, DE (new thermoplastic material); Ticona, GmbH of Frankfurt, Germany (material testing); Progressive Tool & Industries, Southfield, MI (cooling and assembly fixturing); Ashland Chemical, Dublin, OH (bonding adhesives); and Paragon Die & Engineering Company, Grand Rapids, MI (mold designs).

Representing efforts that began with the Composite Concept Vehicle (CCV), prototype hardtops are another stepping stone in what DaimlerChrysler believes could lead to a complete vehicle body made with only six to 12 thermoplastic pieces.

"This could become an essential part of our small car strategy," predicted Holden.

Al Power, Decoma President and CEO noted, "This (phase) is an exciting and challenging project that represents a virtual revolution in how to produce vehicles."