Composites World has run an article that details some of the components that have gone into the 2007 Jeep Wrangler. Their primary focus is on the door assembly that was designed in an effort to maintain the modularity between the half height and full height doors.
The Wrangler door module contract was awarded to Hi-Lex Controls, a subsidiary of Japan’s Hi-Lex Corp. and an existing window regulator provider to DaimlerChrysler. The company was responsible for design, integration, and material and molder selections. “While we manufacture steel door modules at our Korean plants, this was a new challenge for us in the U.S.,” explains Hi-Lex’s director of engineering Tom Strickland. Hi-Lex not only would have to ensure that regulators and purchased components functioned properly on a plastic module plate, the company also would have to work with the door design team, to create a sufficient opening in the inner door panel to facilitate assembly, and with the supplier of the interior trim panel to accommodate their mounting requirements and pull handle support.
For the carrier plate that forms the backbone of the assembly, Hi-Lex enlisted the help of Ticona, already a supplier of thermoplastic compounds for other Hi-Lex components. “We were invited in at the start of the project at the end of 2003,” says Jason Lipke, door systems development engineer for Ticona. “The Jeep engineers had specified long glass polypropylene, and we had an existing relationship, plus the right materials for the job.” The team selected Ticona’s Celstran PP-GF40, a 40 percent by weight glass-reinforced PP in an 11mm/0.43-inch chopped pellet. The same material is used in the rear door latch presenter, while the front latch presenter uses a 30 percent short glass-filled polybutylene terephthalate (PBT) material, also supplied by Ticona. Lipke says that long glass materials offer improvements in impact resistance, including more ductile behavior and better fatigue resistance compared to short glass materials.