Tubular composite containers having folded unsupported film liners

Abstract

A tubular composite container includes a paperboard body ply wrapped into a tubular shape, and a polymer film liner ply wrapped into a tubular shape and adhered to the inner surface of the body ply. The liner strip includes a heat seal layer facing the body ply that is formed of a heat-sealable material, and the inner surface of the liner ply that contacts the mandrel is formed of a hard polymer material whose melting temperature is substantially higher than the sealing temperature at which the heat-sealable material softens and seals to itself. One edge portion of the liner ply is folded inward toward the mandrel, the liner ply is wrapped onto the mandrel such that the folded edge portion overlaps an opposite edge portion of the liner ply, and the heat seal layer on the folded edge portion is heat sealed to the opposite edge portion.

Dependencies are inferred from the claim text.