Cost Effective Molded Polyurethane Foam for Automotive Acoustical Carpet Underlay and Dash Insulators

NVH (Noise Vibration Harshness) control is receiving increased attention in the automotive industry, as the automotive engineers seek new ways to improve vehicle quality and customer satisfaction.

Significant advances in cast (molded) Polyurethane foam for automotive acoustical applications are increasing the cost competitiveness of this technology against more traditional sound deadening media, such as polyurethane slabstock foam (for dash insulators) and die-cut or molded resinated polyester waste fibers (“shoddy pads”) for carpet underlay. This paper details these continuous improvements, which include density reduction without the use of any Chlorofluorocarbon (CFC) blowing agents from 5.0 pcf to 3.0 pcf, and demold time reduction from 5.0 minutes to 2.0 minutes for cycle time (productivity) improvements. While these advantages pertain to economics, advancing technology has also resulted in cast polyurethane systems meeting increasingly stringent physical property requirements, including heat and humid aged tensile strength, fogging and mildew resistance, without compromising acoustical performance. The economic impact of these developments will enable the automotive NVH engineering/design community to expand the use of cast acoustical polyurethane foam to a greater number of North American-built vehicles.