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The use of Low Pressure Moulding (LPM), in its many forms, is becoming more widespread in the Automotive Industry. Design and setup of this process generally relies on experience built up over years of working with the process and often several tool and process changes in the development phase in order to optimise the process. This paper outlines a method of designing for LPM using C-Mold® software from AC-Technology, and the experience of working with the process and materials, which will reduce the number of iterations required to design for LPM and further increase the benefits to be gained by use of the process. The paper shows some of the characteristics of the process and the extent to which this can be simulated using the software.

The major element of contact between the occupant, the vehicle and the road surface is the automobile seat. Flexible polyurethane foams are the material of choice for this application, not only because of the economies offered by large-scale molding operations, but also because the cushioning characteristics of the foam/seat assembly can be adjusted. The automotive original equipment manufacturers (OEM’s) worldwide are looking for optimization of the balance between foam weight and foam specifications, with more emphasis than ever on comfort and durability. This goes with specific requirements for the various foam pads, i.e., front cushion, rear cushion, front backrest and rear backrest. Commercially useful foams can be made from a variety of polyurethane molding chemistries.

The challenging economic climate of today is causing many suppliers to develop new and creative ways to improve efficiency and meet the needs of customers without jeopardizing the quality of service and support. The Dow Automotive business group is evaluating a new mechanism for remotely supporting customers' injection molding trials by combining wireless video camera technology and traditional videoconference (VC) capabilities. The Video Response System™ (VRS), from Teleco Video Systems, incorporates a wireless remote camera on a wheeled tripod and a wireless audio connection to allow users to transmit a real-time video and audio signal from anywhere within a location to other sites around the globe. The video and audio signals generated by the VRS system are transmitted to a traditional VC unit in the molding shop which in turn transmits the signals over ISDN lines to an awaiting VC unit.

Fully-integrated structural instrument panels (IP) have been in commercial use in passenger cars, light trucks, and sport utility vehicles for some years now. They offer a cost-effective alternative to the more traditional IP construction that utilizes full-size cross car beams to achieve the structural stiffness and energy management required to meet Federal Motor Vehicle Safety Standard (FMVSS) 208 and corporate performance requirements. The natural evolution of interior designs demands an increasing level of integration of the different components in the interior of the vehicle. Therefore, the natural extension of current structural IP technology is to integrate the steering column subassembly, i.e., steering column and column support, and the heat, ventilation, and air conditioning (HVAC) unit into a modular pre-assembled system.

Among the various materials used today for an instrument panel application, polypropylene is one of the least expensive per kilogram and therefore one of the most attractive. Typically, different polypropylene compounds may be used in different components of the IP according to the desired performance requirements. At the same time, polypropylene is one of the most difficult thermoplastics to use properly when designing an instrument panel due to weaknesses related to its semi-crystalline nature. For some vehicles, the metal reinforcement which would be needed to overcome these weaknesses would lead to a higher overall system cost compared with engineering thermoplastics. In the last decade significant progress has been made in the development of new polypropylene compounds and processes.

In a joint effort between Ford Motor Company, Visteon Automotive Systems, Textron Automotive Company, and Dow Automotive the 1999 Mercury Cougar instrument panel (IP) was designed and engineered to reduce the weight and overall cost of the IP system. The original IP architecture changed from a traditional design that relied heavily upon the steel structure to absorb and dissipate unbelted occupant energy during frontal collisions to a hybrid design that utilizes both plastic and steel to manage energy. This design approach further reduced IP system weight by 1.88 Kg and yielded significant system cost savings. The hybrid instrument panel architecture in the Cougar utilizes a steel cross car beam coupled to steel energy absorbing brackets and a ductile thermoplastic substrate. The glove box assembly and the driver knee bolster are double shell injection molded structures that incorporate molded-in ribs for added stiffness.

To address the automotive industry's initiative to maximize the utility of each component by decreasing both weight and cost to improve the performance and value of its products, it is logical to try to minimize the thickness of any part whose main function is ostensibly decorative. A example of such a candidate part on the vehicle would be the fascia and body side claddings. The fascia and claddings of vehicles do provide some impact resistance and resiliency functionality to vehicles, but more and more, the energy management functionality is being taken on by improvements in the engineering design and support systems behind the exterior part. The function of these exterior parts then, is, to a large degree, to be aesthetically pleasing when painted, and maintain their high quality fit and finish over the life of the vehicle. These applications are therefore justifiably subject to investigations into the reduction of their wallstock.

An advanced high flow PCABS was developed for improving the efficiency of injection molding processes and cycle times. Proprietary technology was used to develop this new blend while maintaining key properties (heat resistance and impact) necessary to meet end use part requirements. Significant rheological improvements in melt flow rate (MFR) and flow capabilities throughout the entire viscosity versus shear rate range were obtained. These improvements allowed for lower cooling times (21-27% reduction) and injection pressures. Molders using this resin have the potential to improve cycle times, improve processes, and save money. This paper will document cycle time and process improvements in automotive instrument panel applications with the new high flow PCABS blend, PULSE*2000EZ.