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The well-known hazards of diphenylmethane diisocyanate (MDI) have resulted in the development of foams with low MDI emissions for use in vehicle body cavities. While low MDI acoustic foams have been successfully launched in the automotive market, non-standard dispense equipment has been required. The latest low MDI acoustic foam development is dispensed via standard meter mix equipment, at the volumetric ratio of 1:1, enabling capital reduction for ventilation and application processing. This paper describes the benefits associated with using a 1:1 low MDI foam system. Industrial hygien testing and qualification of this system as low MDI are reviewed. Acoustical performance testing including insertion loss and sound absorption are discussed.

Automotive body structures are developed to meet vehicle performance requirements primarily based on ride and handling, crashworthiness, and noise level targets. The body is made of a multitude of sheet metal stampings welded together. Other closures such as fenders, hood, doors and trunk lid are developed to match body interfaces, to contribute and participate in the overall vehicle response, and to meet the sub-system and system structural requirements. In order to improve performance and achieve weight reduction of the overall vehicle steel structure, new polymeric materials and treatment strategies are available to body structural engineers to optimize the response of the vehicle and to tune vehicle performance to meet specified functional requirements. If early integrated to the design cycle, these materials help not only improve the structural body response, but also decrease the weight of the integrated body structure.

Advanced high strength steels (AHSS) are becoming major enablers for vehicle light weighting in the automotive industry. Crash resistant and fracture-toughened structural adhesives have shown potential to improve vehicle stiffness, noise, vibration, and harshness (NVH), and crashworthiness. They provide weight reduction opportunity while maintaining crash performance or weight increase avoidance while meeting the increasing crash requirement. Unfortunately, the adhesive bonding of galvanneal (GA)-coated steels has generally yielded adhesive failures with the GA coating peeling from the steel substrate resulting in poor bond strength. A limited study conducted by ArcelorMittal and Dow Automotive in 2008 showed that GA-coated AHSS exhibited cohesive failure, and good bond strength and crash performance. In order to confirm the reliable performance, a project focusing on the consistency of the adhesive bond performance of GA-coated steels of 590 MPa strength level was initiated.

The commercial validation of a optimized RRIM polyurethane substrate with a novel barrier coat for fascia applications is reviewed which creates cost competitiveness to thermoplastic olefins (TPO), without sacrificing performance. Meeting fascia performance requirements with thinner and lighter RRIM materials containing recyclate and the subsequent application of a barrier coat eliminating the traditional primecoat cycle was investigated.

An innovative seat back design for fold down split-rear seat backs has been developed for application in SUV’s, MPV’s and hatchbacks. The all-thermoplastic seat back design meets US and European government regulations such as, the FMVSS 210, 207 in the US, and ECE 17 (luggage retention) in Europe. It is also expected to meet the newly introduced FMVSS 225 (child seat belt tether load) requirement. Currently application of the blow molded seat back is limited to sedans where the seat belt anchor loads are transmitted to a steel package shelf. For applications where the seat-belt anchor loads are transmitted to the seat back, hefty steel frame and reinforcements are required which add weight and cost to the seat back. The same is true for seats that need to comply with the European luggage retention requirement.

The intent of this paper is to summarize the work of the V8 power plant intake manifold radiated noise study. In a particular V8 engine application, customer satisfaction feedback provided observations of existing unpleasant noise at the driver's ear. A comprehensive analysis of customer data indicated that a range from 500 to 800 Hz suggests a potential improvement in noise reduction at the driver's ear. In this study the noise source was determined using various accelerometers located throughout the valley of the engine and intake manifold. The overall surface velocity of the engine valley was ranked with respect to the overall surface velocity of the intake manifold. An intensity mapping technique was also used to determine the major component noise contribution. In order to validate the experimental findings, a series of analysis was also conducted. The analysis model included not only the plastic intake manifold, but also the whole powertrain.

Adhesive bonding technology is rapidly gaining acceptance as an alternative to spot welding. This technology is helping automobile manufacturers reduce vehicle weight by letting them use lighter but stronger advanced high strength steels (AHSS's). This can make cars safer and more fuel efficient at the same time. The other benefits of this technology include its flexibility, ability to join dissimilar materials, distribute stress uniformly, provide sealing characteristics and sound dampening, and provide a moisture barrier, thus minimizing the chance for corrosion. The lap shear work reported in the late 1980s and early 1990s has led to the prevalent perception that the galvannealed (GA) coating can delaminate from the steels, resulting in poor joint performance. However, the above work was carried out on steels used primarily in automobile outer body panels.

The use of two-component polyurethane foam materials to improve sealing, stiffness, and crash performance in vehicle structures has increased significantly in the past 10 years. The proven cost and performance advantages associated with polyurethane chemistry, along with recent development efforts by Dow Automotive to minimize industrial hygiene concerns traditionally associated with polyurethane use [1], have resulted in increased activities associated with design, application development, and launch of foam systems in the automotive industry. This paper describes the key considerations that must be addressed to successfully incorporate polyurethane foams into vehicle structures from design, application development, and launch perspectives.

Extensional damping materials are commonly used in the automotive industry to control structure-borne noise. Using the dynamic properties of the material or composite panel, these materials can be represented in vehicle finite element or statistical energy analysis (SEA) models. However, in order to make the detailed design changes to the damping material treatment, proper characterization of the material properties is required. This paper discusses the method of measuring and validating the complex modulus of an extensional damping material using the Oberst beam technique [1]. Also, it is shown that the Ross, Kerwin, Ungar (RKU) analytical model can be utilized to predict damping of composite panels for SEA models [2]. SEA modeling of various composite panel constructions will be examined with supporting measurements.

Dow Automotive has developed an ACM DPF substrate, characterized with light-weight, low pressure-drop, rapid regeneration, and excellent chemical resistance at high temperature. An uncatalyzed DPF was tested on a 2.0L common-rail diesel engine for over 100 soot loading and regeneration cycles, which included a combination of controlled regenerations, uncontrolled regenerations and incomplete regenerations. The DPF demonstrated high filtration efficiency and physical integrity throughout the entire test. The ACM DPF has also demonstrated excellent catalyst coating capability and performance. An ACM DPF with a total volume of three-liter and coated with the same catalyst formulation as the original catalyzed DPF, was used to replace the OEM four-liter catalyzed SiC DPF on a 2005 model-year 1.9L European diesel passenger car. It was demonstrated that the ACM DPF has lower pressure drop and faster regeneration than that of the OEM DPF.

In structural Instrument Panels the conventionally used cross car beam is eliminated by using the plastic structure as a load carrying construction. Due to the continuous search for lowering costs and weight in the development of new cars, the concept has been applied a number of times. Many articles have been published since on this subject, describing the design concepts, engineering development and types of plastic material applied. In general, the structural instrument panel assemblies show to have substantially lower cost and weight compared with conventional cross car beam based instrument panel structures while all of performance requirements are met. Also, improved packaging space, reduction in assembly time and improved recyclability are seen as major advantages. The use of state of the art Computer-Aided Engineering (CAE) has proved to reduce development time and costs.

The 1997 F-Series and Expedition Instrument Panel programs were initially launched with steering column and glove compartment knee bolsters constructed of compression molded, glass filled polypropylene. First run capability of the material at production speeds was only 65 percent due primarily to dimensional stability (warp), paint adhesion, and excessive rework issues. A Ford APO (now Visteon) / Dow Automotive† team was formed to seek a replacement material / design for the glass filled polypropylene material which would solve the problems. The new material system had to meet or exceed current FMVSS 208 crash performance standards, provide improved quality and reduce variable and scrap costs all with a minimum tooling investment. Using Dow PULSE™ PC/ABS resin, the team designed / implemented a new knee bolster system in 12 months.

Car manufacturers continue to strive to find creative routes to differentiate their vehicles while continuing to reduce cost. Acoustic comfort derived from high performance sprayable dampener systems is one important option for OEM's to differentiate their models. But there is a significant conflict between high performance, low cost and vehicle weight reduction. This paper describes an innovative vibration dampening material resin. It is a one part, reactive, solvent free, sprayable, epoxy based technology using a unique polymer resin with reduced safety labeling requirements. Good corrosion protection and oil absorption characteristics allow this resin to be applied in either the body or paint shop facilities. Benchmarking against the existing dampener type in the areas of damping performance, process costs, ease of application and environment/health aspects shows that this new generation of epoxy damper is superior to other current damper coatings.

Pedestrians forming the most important casualty of road accidents, European countries have brought in new laws for vehicles to be made safer for pedestrian impacts. The needs of pedestrian safety are different from current requirements such as low speed or insurance impacts. To fulfill both traditional vehicle to vehicle and pedestrian safety requirements, design changes are needed to find a good balance. However, design limitations are imposed in order to conserve the styling and aesthetics of the front end, which define the image and often handling/aerodynamics of the car. Thus, numerous boundary conditions, both mechanical and non-mechanical, should be taken into account during the implementation of pedestrian safety solutions. This study breaks out part of vehicle front profile, which can be explicitly given values. These values have been based on 2-D simulations conducted across four vehicle categories available in the Indian scenario.

Automotive manufacturers are driving for improvement, creativity and innovation in vehicle systems in order to differentiate products in the global market. Progress in fuel efficiency, occupant safety, comfort, recyclable friendly pre-assembled modular systems, and novel manufacturing methods is difficult to achieve if no major departure from the traditional design, engineering, material mix, and assembly approaches is considered. More importantly, these benefits will not materialize unless the relationship between automotive manufacturers and suppliers changes, allowing suppliers to take a more active role in the vehicle development process. The present paper explores achievements made towards the development of new, innovative technologies to address simplification and overall performance improvements using non-traditional materials.

Low density polyurethane foam, applied in general assembly, is being used as a replacement for rubber-based heat reactive baffles in automobile cavities to inhibit noise transmittance. Most chemically reactive urethane foam systems used in barrier applications are MDI-based (diphenylmethane diisocyanate). The use of classical MDI-based technology in assembly plants typically requires substantial levels of ventilation [1]. High capital and operating expenses associated with plant ventilation systems have hindered the growth of polyurethane technology. This paper describes benefits of using a low MDI polyurethane foam system in place of classical two-component MDI-based foam systems and conventional rubber-based heat reactive baffles. Severe industrial hygiene testing has indicated that ventilation requirements to use the low MDI foam system in assembly plants may be greatly reduced.

Polyamide resins are well established within the automotive industry and are widely used in a range of demanding under-the-hood applications such as valve covers and air intake manifolds. In reality however, the disadvantages of conventional nylon products, such as excessive warpage and poor dimensional stability to name but two, make it increasingly difficult for engineers to produce the ever more complex parts demanded by new engine developments. In this paper we shall introduce a new range of modified Dow Polyamide resins that greatly reduce the above mentioned disadvantages. In comparisons with commercially available nylon 6 and 66 materials we shall illustrate improved warpage behaviour and lower moisture pick-up in combination with excellent chemical resistance to, for example, hot motor oil and ethylene glycol. In summation, examples will be provided to illustrate the improved utility of these new, modified Dow Polyamide resins.

This paper describes the application of pore-scale filtration simulations to the advanced ceramic material (ACM) developed for use in advanced diesel particulate filters. The application required the generation of a three-dimensional substrate geometry to provide the boundary conditions for the flow model. An innovative stochastic modeling technique was applied matching chord length distribution and the porosity profile of the material. Additional experimental validation was provided by the single-channel experimental apparatus. Results show that the stochastic reconstruction techniques provide flexibility and appropriate accuracy for the modeling efforts. Early investigation efforts imply that needle length may provide a mechanism for adjusting performance of the ACM for diesel particulate filter (DPF) applications. New techniques have been developed to visualize soot deposition in both traditional and new DPF substrate materials.

Diesel particulate filters (DPF) made from Dow's advanced ceramic material (ACM) have already demonstrated high filtration efficiency, low pressure drop, and high temperature performance capabilities. In addition to these advantages of the ACM-DPF, it has been found to be well suited for use in combination with various catalyst coatings while maintaining it's overall advanced performance over a broad range of catalyst loadings. Our recent studies on catalyzed ACM DPF demonstrate that the unique micro structure of ACM is able to maintain significant amount of catalyst and washcoats. The characteristics of the ACM DPF pressure drop versus catalyst washcoats loading have been fully investigated. With defined coating techniques, ACM DPF can be loaded with three times the amount of washcoat than can a Silicon Carbide DPF without significantly increasing the pressure drop.

The application of two-component polyurethane (PU) foam materials for acoustical and structural performance enhancements in vehicle structures have increased significantly in the past ten years. The benefits include NVH management (through effective cavity sealing), body stiffness improvements and energy management in crash applications. These PU foams can either be pumped into body cavities in the OEM assembly plants (bulk applied) or can be pre-molded into Structural Foam Inserts (SFI) and installed in the body-shop prior to full frame assembly. The choice of application type depends on vehicle-specific requirements and assembly plant criteria. The chemistry, plant application and benefits associated with bulk PU foam has already been cited in previous work.1, 2, 3 This paper showcases BETAFOAM™ SFI technology developed by Dow Automotive that complements traditional bulk foam technology.