Composite sound absorbing sheet esp. for bonding to metal - has layer containing voids, thermoplastics layer and metal foil

摘要

A composite plate or panel comprises a thermoplastics sound- absorbent layer of max. thickness 5mm, a layer of organic material containing numerous cavities and of max. thickness 15mm on one side of this layer, and a metal foil of max. thickness 0.5mm on the opposite side. In a preferred embodiment, the open side of the layer containing cavities is faced with adhesive, onto which apeel-off foil is placed.. Used in partic. for bonding onto metal plates which emit noise, esp. of low frequency.