Tailor-Made All MDI Based Moulded Floor Systems for the Automotive Industry

MDI based, CFC free, moulded polyurethane foam floor pan carpet composites are in production world wide. They will play an increasingly important role as a versatile and economic solution to the reduction of interior vehicle noise. This paper reviews current processing experience with ICI all-MDI acoustic foam systems and describes some of the results of the acoustic development programme which has been underway for the past two years. Simple model representations for airborne and structure borne noises are presented and analysed. A laboratory test rig is described which is used for the evaluation of the airborne noise and vibration radiated noise Insertion Loss of non-bonded carpet composites. Data are presented showing how system and material design parameters affect acoustic performance. Analysis of data shows that performance is controlled primarily by system parameters, namely area mass of heavy layer and thickness of foam isolating core. It is shown that control of foam properties such as density, stiffness, and clamping can be used to optimise system performance for a vehicle having a particular noise and vibration signature.