Inventors:
Keith M. Hankel - Dayton OH
International Classification:
E04B 199
G10K 1104
Abstract:
An improved acoustical material, which is simple in construction and uses conventional, inexpensive materials, for use as a lining material in association with noise generating machinery, comprising, in combination, a composite layer of plural layers of porous material which will not deteriorate, swell or retain oil, solvents, or water such as are found in machinery, and which has acoustical flow resistance of between 20 rayls and 80 rayls, and a highly porous layer which is or acts as a dead air space relative to the composite.