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Damping materials are applied to the vehicle body during production to provide passenger comfort by reducing noise and structural vibration through energy dissipation. Noise, Vibration, and Harshness (NVH) Engineers identify critical areas of the vehicle body for material placement. Damping materials, which include liquid applied dampers, are typically applied directly on the structure, covering large areas. These film forming materials can be spray applied using automation and, after baking, result in a cured viscoelastic damping layer on the target substrate. Typical liquid applied dampers contain an aqueous dispersion of film forming polymer which functions to bind inorganic materials together in the coating and provide a composite structure that dissipates energy. Representative damping coatings were prepared from dispersions of polymers with varying viscoelastic properties and chemical compositions.

The blow molded knee bolsters on the 1996 Chevrolet Astro and GMC Safari vans are the first blow molded parts used on an interior structural application. These knee bolsters also meet FMVSS 208 requirements. The one-piece bolsters, used on both the driver's and passenger's sides of the vehicle reduced cost by $4.00 and weight by 40% per vehicle compared with two-piece, steel-reinforced plastic knee bolsters. Additional savings were realized in tooling cost reductions of $300,000 and a development time that was shortened by 64 weeks. Part testing was also reduced to the tunability of the process. Aesthetic concerns of matching adjacent injection molded and vinyl parts were also met. This paper discusses the combination of material, processing and tooling technologies that made this program a success.

The advantage of internal mold release in the production of automotive parts such as exterior fascia and body panels is well known. Recently a new type of internal mold release technology has emerged in the area of low density RIM for interior door panels. Products have been developed for both low density reinforced RIM and structural RIM applications without sacrificing physical properties. This latest technology has the potential for producing hundreds of parts after a single application of external mold release. The exact number of parts that can be obtained will vary depending on several factors including the initial condition and design of the mold. Although able to release from aluminum or steel, adhesion to vinyl cover stock is not greatly affected. Therefore, these products can be used for both pour behind vinyl and substrate only applications.

GENERAL techniques used in the weld repair of magnesium aircraft castings by both gas and arc welding methods are described here. Coverage is given to equipment, methods of surface preparation, preheating, welding procedure, post-heat-treatment. Some typical arc weld repair jobs are described and illustrated. Included also are descriptions of weld defects encountered because of poor welding technique. Typical mechanical property data are shown.

The human factor will always be a deterrent to achievement of 100% safety in automobiles, but new design and materials have considerably narrowed the margin of risk in highway accidents. This article considers the contributions made by the chemical industry in providing materials suitable for this purpose. Improvements in crash padding, hydraulic fluids, and gas tanks have greatly reduced injuries attributable to impact, fire, and brake failure. The close cooperation of the automotive and chemical industries is duly credited for these safety efforts. Emphasis is placed on the need for integration of inspection, driver education, highway design, and traffic laws with enforcing agencies in order to perfect overall in-use protection.