Abstract: This invention is directed to a liner for venting excessive internal pressure of an associated container, the liner including at least two plies of plastic material in which a first ply is formed of impermeable plastic and a second ply is deformable when subjected to a compressive force, the second ply including a plurality of indentations, the material in the areas of the indentations of the second ply are compressively deformed whereas second areas of the second ply are generally uncompressed or less compressed whereby when the liner is associated with a container and closure venting is permitted either through vents formed between a sealing lip of the container and the first or second areas depending upon the axial load of the closure relative to the container as determined by the torque involved in applying the closure to the container.

Abstract: This invention is directed to a liner for venting excessive internal pressure of an associated container, the liner including three plies of plastic material in which a first ply formed of foam plastic is sandwiched between second and third plies which are impermeable, the second ply including a plurality of indentations opening in a direction away from the third ply, such that the material in the areas of the indentations of the first ply are compressively deformed whereas second areas of the first ply are generally uncompressed or less compressed whereby when the liner is associated with a container and closure venting is permitted either through vents formed between a sealing lip of the container and the first or second areas depending upon the axial load of the closure relative to the container as determined by the torque involved in applying the closure to the container.