Polyurethane Decoupling Foam with Variable Stiffness and Thickness: Insulation Performance versus Their Mechanical and Transport Properties

Polyurethane foam (PU foam) is widely used in automotive noise reduction palliatives. As a decoupling insulator its acoustic performance depends on intrinsic properties, called “Biot” parameters. An important decoupling parameter is the apparent stiffness of the PU foam cell structure, as this controls the transportation of vibrational energy, with “softer PU foam” being the preferred option. However, some areas of application, for example in automotive carpet design, requires stiffer PU foam in order to accommodate under foot comfort. For a comprehensive approach to automotive component design, it is necessary to calculate the appropriate spatial PU foam properties ideally without the need for series of prototypes. This paper describes the methods and processes used when compiling and validating a material database capable of predicting the acoustic performance of flat sample or spatially complex 3D component with minimal prototype manufacture.