Flat, inelastic, dimensionally stable sheet material is formed by stretching parallel elastomeric strands to several times their relaxed length and then bonding them to one or more flat, inelastic webs with inelastic thermoplastic polymer. When the sheet material is heated, the strands contract and the...http://www.google.com.au/patents/US4552795?utm_source=gb-gplus-sharePatent US4552795 - Inelastic, heat-elasticizable sheet material
