Closed Cell Foam: A Sound Barrier and More

Sound barrier materials come in many varieties. They are generally described as being dense, high mass, and impervious to airflow. Until recently, lightweight foams have not generally been recognized or utilized as sound barriers. However, closed cell foam is an effective sound barrier that performs in accordance with the Mass Law. It can be used in many applications where a lightweight barrier is sufficient, avoiding the penalty of excessive mass relative to the noise reduction required.

Sound absorption does not generally accompany the sound transmission loss performance of a sound barrier material. Recently developed closed cell foam with significant sound absorption properties is described.

This paper describes the production of closed cell foam and the fabrication of parts from this material. A visual tour of material production and part fabrication is presented. Material characteristics and typical applications are described.