LAMINATED PERFORATED SOUND-ABSORBING FOAMS

PROBLEM TO BE SOLVED: To provide a process of manufacturing relatively thick sound-absorbing foams useful for acoustical attenuation, which resolves problems in perforating foams to facilitate blowing agent dissipation and to reduce airflow resistivity.SOLUTION: A process for making an acoustically active polymeric foam comprises the following steps: (a) providing at least two initial polymeric foams, each having opposing major surfaces; (b) perforating the initial polymeric foams all the way from one major surface through the foam to the opposing major surface to form perforated polymeric foams having perforation channels that extend in a continuous and linear fashion all the way through the perforated polymeric foam; and (c) laminating the perforated polymeric foams together such that a perforated surface of one perforated polymeric foam adheres to a perforated surface of another perforated polymeric foam.