aerated plastic

foamed plastic, plastic foam

1. A plastic expanded chemically, mechanically, or thermally, to form a lightweight closed-cell structure; used as thermal insulation. Also see chemically foamed plastic.
2. A resin in a sponge form, either flexible or rigid, with cells that are either closed or interconnected.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.