Search Results

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.

PC/ABS blends have been used with much success in energy management applications for the last 10 years. These systems are typically injection molded; however as blow molding technology advances, a re-examination of applicable applications is warranted. The attributes of the two molding techniques will be compared in a technical manner to illustrate which process delivers the most cost effective solution for automotive interior impact components. Material morphology and property consistency, energy management capability, weight savings, and total systems costs will be explored. Both fabrication techniques will be examined using FEA simulations to demonstrate energy management and weight savings. High magnification microscopy will depict part microstructure for both techniques, illustrating differences in morphology and rubber phase orientation in PULSE* Polycarbonate-Acrylonitrile-Butadiene-Styrene Blends (PC/ABS).

Many studies have been done to objectively measure car seat foam properties and correlate them to comfort performance. Typically, the vibration characteristics (namely transmissibility) of the foam cushion are measured. It has been generally accepted that low natural frequency equates to better comfort. However, no subjective studies have been done to verify that humans can feel the vibration differences that are measured. Also, the measured differences of the foam may not be detectable once the foam is built into a complete seat. Three different foam formulations utilizing MDI (methylene diphenyl diisocyanate) and TDI (toluene diisocyanate) technology were evaluated for vibration characteristics. The foams were then submitted to subjective human testing and objective lab testing after being built into seats. The subjective testing was done using a typical ride and drive evaluation where people were interviewed about the comfort of the seat while driving over various road conditions.

The drive to reduce costs and increase efficiency in the automotive industry is often the driving force for development of new technologies and methods of engineering. Polypropylene (PP) is widely used as a low cost alternative to “engineering” thermoplastics. This paper outlines the characterisation methods used to develop material models for talc-filled impact-modified PP, which are then used to increase the efficiency of the development process, by using engineering analyses to reduce the prototyping costs and potentially the development time for an application. Instrument panels (IPs), door panels and trim parts are usually subjected to heat requirements and must maintain dimensional tolerance levels for each application. This necessitates extensive prototype testing and often several design iterations in order to reach the requirements. This paper deals with the characterisation of PP creep behaviour and development of a model for use in Finite-Element (FE) - based codes.

The platform strategy broadly used by OEMs across their different brands, as well as the increasing targets in terms of cost, weight and performance are driving forward since several years the modular approach for a new generation of instrument panels. An innovative hybrid concept has been developed in order to integrate the HVAC system with the structural IP components, reducing cost and weight, improving thermal comfort and structural performance, with at the meantime high style flexibility. The integration of metallic and thermoplastic components, together with a structural use of plastic parts, has driven to the development of different modular concepts. Each of these concepts has been screened and optimized using engineering tools such as finite element analysis (FEA) and computational fluid dynamics (CFD) in order to assess the structural, noise-vibration-harshness (NVH), airflow and cool-down performance.

The material data provided by resin suppliers in their product datasheets generally focuses on single point data only and does not include the data useful to the design engineers. Even though the single-point data bears little relevance to the end-use performance of the material and provides very little insight into its behavior, design engineers rely heavily on these data because it is readily available. However, to enhance their confidence in their material selection decisions, they ask for large quantity of data without taking into consideration the cost of data measurement. Today, as resin suppliers struggle to justify the cost of generating all the data requested against the tremendous pressure to reduce their cost, it is important to put the direct costs of material data measurement in perspective.

This paper will present data that is the result of testing several rigid plastics by exposure to several automotive fuels. The fuels were selected from a list of fuels that have been suggested by several customers in the automotive industries. They are representative of fuels in service today and fuels that are expected to be used in the future. The plastics were selected because they are candidates for use in the rigid components of fuel handling systems. These plastics might be used in fuel filter housings, quick connectors, fuel rails or throttle bodies. The data are presented to provide design engineers with some of the information necessary for the design of rigid plastic components for fuel handling systems.

In the present paper the engineering development of a structural instrument panel (IP) concept made of a Polypropylene (PP) rubber modified compound filled with 15% talc in which the metal cross car beam has been eliminated, is discussed. The design concept consists of three main injection molded shells which are vibration welded to each other to form a stiff structure. The steering column is attached to the BIW and plastic structure by means of a separate column support made of steel, aluminum, magnesium or fiber-reinforced plastic. The concept has been developed for the European market and is therefore not intended to meet the unbelted FMVSS 208 requirements. The total IP assembly has a substantially lower cost and weight than conventional cross car beam based IP structures while meeting all of the performance requirements. The concept development was supported by static and dynamic numerical analyses using well established, widely used FEA codes.

A new test methodology has been developed to quantify the performance of vehicle cavity fillers. This test methodology focuses on the vehicle Body in White (BIW) and provides a proper test environment for individual cavity fillers. Since the focus of the methodology is BIW, the proper boundary condition is automatically implemented and the results obtained from this test methodology can be utilized for an actual comparison of noise reduction (NR) performance for different cavity fillers. In this study a noise source generator was placed at different locations within the vehicle body to generate the desired noise level. The goal was to realistically simulate wind, tire and the powertrain noise sources at the vehicle level and evaluate the performance of the cavity fillers. By placing several microphones in the vicinity of the A, B, C and D pillars, the noise reduction performances of the individual cavity fillers were obtained.

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.

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.

The trend in the automotive industry to establish higher quality, comfort and safety levels, while at the same time reducing cost and weight, is pushing production techniques, materials and the development cycle to become as efficient as possible. The automotive supplier has to choose from a broad range of fabrication technologies and material alternatives to achieve the highest performance level at the lowest possible cost. This paper outlines the process followed by a multi-functional team to design and develop the interior door panels for the VW Golf, in ABS resin for large scale production. The team effort, headed by the Tier 1 (Sommer Allibert Industrie), with extensive interaction with the OEM, and the support of the material supplier and tool-maker, led to a thin-walled part with integrated mountings, high quality appearance and excellent dimensional stability.

The QUESTRA* Crystalline Polymer product family, based on syndiotactic polystyrene (SPS), has been improved to meet the needs of the automotive connector and light socket applications in a very cost effective manner. In this paper, the attributes of two new SPS formulations, SPS/polyamide (PA) blends and low gas SPS formulations, are compared to existing SPS formulations and competitive resins. It is shown that the SPS/PA blends have significantly improved strength and ductility over existing SPS formulations. This improves the SPS formulation technology to include the full range of strength and ductility options the designer of automotive connectors needs to achieve the terminal retention forces and latch deflection distances necessary for the smaller connectors like the .64 mm terminal systems that the automotive industry is migrating towards.

Currently, throughout the automotive industry, a major emphasis is being placed on reducing costs of plastics part manufacturing. For example, manufacturers of plastics parts used for interior trim applications have traditionally painted parts, to improve part aesthetics and cover over such surface defects as weld lines. Part painting can typically add from $.60-$2.00 to the part costs for these applications. Furthermore, due to the loss in mechanical properties found at weld lines, structural integrity can also be sacrificed. This paper discusses the use of the multi-live feed molding process as a solution to minimize weld lines, improve mechanical properties and part aesthetics, and potentially reduce costs by eliminating steps in manufacturing operations such as painting.

Field cracking in some instrument panels (IP) manufactured with a competitive grade of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) material was observed in high temperature/high humidity geographies. OEMs and tier molders are: 1) questioning the thermal and hydrolytic stability of the various suppliers' PC/ABS resins, and 2) converting to grades with advantaged stability. A study was undertaken to compare the thermal and hydrolytic stability of two suppliers' high flow PC/ABS resins. Materials were aged at 90C/95% relative humidity up to 1000 hours. Samples were tested to compare the retention of properties. This paper will discuss the experimental procedures, resulting data, and the common factor in the PC/ABS resins showing the best stability.

This paper describes a comprehensive hybrid technique developed for optimization of damping materials on vehicle bodies. This technique uses finite element analysis (FEA) along with experimental techniques to complement each other. In this particular application, a hybrid technique was used to address floorpan vibration and the resulting radiated noise. The objective of this approach was to develop an optimized damping material application layout. This optimized layout balances the increased performance with the overall material volume, mass, and cost. The optimized damping material application developed resulted in a 3-5 dB reduction in the floorpan vibration level while saving 10% in material volume and mass. This optimized layout was validated on a body-in-white using a laser vibrometer. In addition, a new liquid applied material was also introduced with better damping characteristics.