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The adoption of head-up displays (HUDs) is increasing in modern automobiles. Yet integrating this technology into vehicles with standard windshield (WS) laminates can create negative effects for drivers, primarily due to the thickness of glass used. The double ghosting in HUD images is typically overcome by employing a wedged PVB between the two glass plies of the laminate. Another solution is to reduce the thickness of the glass without impacting the overall windshield toughness. Although this still requires the use of a wedged PVB to eliminate HUD ghosting, the thinner glass provides opportunity to increase the image size. However, reducing the thickness of a soda-lime glass (SLG) ply or plies in a conventional soda-lime glass (SLG) laminate can significantly impact the robustness of the laminate to external impact events.

Quantitative in-use pressure measurements were taken from packaging ceramic substrates with the SoftMountSM technology and two more traditional technologies, stuffing and tourniquet. Each technology was assessed using four separate mat materials. Mat selection enhanced the application of the SoftMountSM technology through the reduced pressures applied to the substrate during packaging. High temperature and low temperature thermal cycling studies were performed on the canned converters for the three packaging technologies so that an evaluation could be made of converter durability. The SoftMountSM packaging technology yielded the lowest pressures of all the processes studied, regardless of mat type. The laminar hybrid mat evaluated yielded the best combination of pressure and durability performance. Low temperature residual shear strengths following thermal cycling of the converters showed good correlation between the SoftMountSM technology and the stuffing method.

An analytical model for estimating shear and bending stresses during canning of cordierite ceramic catalyst supports is presented. These stresses arise when the radial pressure distribution is nonuniform due, primarily, to variations in gap bulk density (GBD ) of intumescent mat around the perimeter of the substrate. Variations in GBD can occur during canning, regardless of the canning technique, due to anisotropic can stiffness or component tolerances or mat overlap. The model helps relate shear and bending stresses to substrate size and orientation, elastic modulii, cell size and wall porosity. If these stresses approach the corresponding strength of substrate, a shear crack may develop during or after the canning process depending on the magnitude of stress. A special test fixture was developed to measure the shear strength of ceramic catalyst supports, with different cell sizes, before and after the application of washcoat.

This paper focuses on the effect of temperature on biaxial strength of curved, symmetrically laminated, automotive windshields. In view of their aspheric curvature, the measurement of biaxial strength requires a special ring-on-ring test fixture with compliant loading and support rings. The key factors that affect strength are (i) fatigue behavior of surface flaws, (ii) expansion mismatch between glass and PVB interlayer, and (iii) interfacial bond integrity. These, in turn, depend on the operating temperature which for automotive windshields can range from −40°C in winter to +50°C in summer. The data show that the biaxial strength is 21% higher at −40°C and 28% lower at +50°C than that at room temperature. An assessment of fatigue and interfacial bond integrity shows that strength changes of these magnitudes are predominantly caused by residual stresses arising from expansion mismatch between glass and PVB interlayer.

One approach to the remediation of NOx generated under lean automotive engine conditions is its controlled storage and then periodic release and reaction under enriched conditions. This process is being considered for automotive exhaust systems that will be operated pre–dominantly lean for reasons of fuel economy. Because of the special characteristics of alkali and alkaline earth elements in the presence of NOx, they are being considered for use, in conjunction with γ–alumina–based washcoats and precious metal catalysts, as NOx catalyst coatings on cellular supports. It is known that alumino–silicates will react with alkali and alkaline earth elements to form stable ceramic phases when mixtures of the components are held in direct contact at elevated temperatures.

The monolithic, large frontal area (LFA), extruded ceramic substrates for diesel flow-through catalysts offer unique advantages of design versatility, longterm durability, ease of packaging and low Cost [1, 2]*. This paper examines the effect of cell density and cell size on catalyst light-off performance, back pressure, mechanical and thermal durability, and the steady-state catalytic activity. The factors which affect these performance characteristics are discussed. Certain trade-offs in performance parameters, which are necessary for optimum systems design, are also discussed. Following a brief discussion of design methodology, substrate selection, substrate/washcoat interaction and packaging specifications, the durability data for ceramic flow-through catalysts are summarized. A total of over 18 million vehicle miles have been successfully demonstrated by ceramic LFA catalysts using the systems design approach.

The motorcycle emissions regulations for both two-stroke and four-stroke engines, which are receiving worldwide attention, will go into effect in the very near future. To meet these regulations, the motorcycles will require a catalyst in conjunction with the muffler due to space limitations. The combination of high engine speeds, high vibrational acceleration, high HC and CO emissions, high oxidation exotherms, and stringent durability requirements, points to cordierite ceramic substrate as an ideal catalyst support. However, as an integral unit within the muffler, its packaging design must be capable of withstanding isothermal operating conditions which may exceed the upper intumescent temperature limit of the ceramic mat. This paper describes a durable packaging design for the ceramic catalyst which employs a hybrid ceramic mat, special end rings and gaskets, and high strength stainless steel can.

The stringent durability requirements approaching 100,000 vehicle miles for automotive substrates and 290,000 vehicle miles for large frontal area diesel substrates for 1994+ model year vehicles call for advanced packaging designs with thick ceramic mats and high mount densities. The latter result in high mounting pressure on the substrate and enhance its mechanical integrity against engine vibrations, road shocks and back pressure forces. A novel measurement technique which applies a uniform biaxial compressive load on the lateral surface of ceramic substrates, thereby simulating canning loads, is described. The biaxial compressive strength data obtained in this manner help determine the maximum mounting pressure and mat density for a durable packaging design. The biaxial compressive strength data for both round and non round substrates with small and large frontal area are presented.