Mass and cost savings remain strong drivers underlying material and process selection. Plastics have long been the materials of choice in many automotive applications based on the mass, cost, and other attributes that they offer relative to their metal counterparts. As structural demands increase, however, there comes a point at which plastics are no longer viable unless they are reinforced.
Composites Products Incorporated has developed a proprietary in-line compounding thermoplastic compression molding process for forming glass reinforced thermoplastic parts. This process has been used to fabricate applications as diverse as skid plates, seat bases, and front-end module housings. As an example, Volvo is a licensee of the technology and molds the front ends of its S-70 and S-80 models using in-line compounding.
The advantages of CPI's technology over competing processes are many. First, through the clever and patented use of a two-extruder system, the length of the reinforcing fiber is maintained, thereby maximizing physical properties. Second, because “raw” resin and glass are processed inline with the molding process, the process eliminates a “middle man” greatly reducing costs. Finally, because composite formulations are set in-house, it is possible to “dial a composition” tailored to the requirements of the application. With modern equipment and controls, these compositions can be reliably switched “on-the-fly.” In this paper, IBIS and CPI will present a synopsis of the in-line compounding and compression molding technology. This synopsis will include a review of process flow, performance properties, and process economics.