Title: Unconstrained Layer Damping and the Use of Modified PVA as a High Efficiency Lightweight Material
text: A lightweight polymeric visco-elastic sheet material has been developed called ‘Dedpan’ (thickness 600 micron, surface weight 1.25 Kg/m2). It exhibits excellent vibration damping performance when used as an unconstrained layer on sheet metal panels. Geiger plate decay rates of 26 dB/sec have been measured. The sheet is flexible, non-toxic, and meets automotive and building flammability specifications. The material composition is stable under paint stoving conditions (temperature up to 200°C), and the product has a tendancy to drape form to underlying structures when hot. These properties make it ideally suitable for the vibration deadening of automobile body panels.