Patent ID: 8092878

Claim:
A container assembly comprising: a container; and a multi-material, elastomeric, cryogenic plug or plunger for the container, wherein the cryogenic plug or plunger includes: a base of cryophilic elastomer forming a core having at one end a first peripheral sealing surface engaging an inner wall of the container and a sidewall at a second end of the core, a cover of non-cryophilic elastomer molded over the second end of the core, the cover having at least one second peripheral sealing surface for sealingly engaging the inner wall of the container and wherein the second peripheral sealing surface is positioned between the inner wall of the container and the core, the non-cryophilic elastomer having a glass transition temperature (Tg) above about −80 degrees Celsius, and the cryophilic elastomer having a glass transition temperature (Tg) below about −80 degrees Celsius.