Paper-based composite container for off-gassing products, and method for making same
A substantially paper-based composite container for an off-gassing product includes a paperboard can body having a substantially gas-impervious liner attached to an inner surface thereof, and a pair of substantially paper-based end closures attached to the opposite ends of the can body, each end closure defining a generally cylindrical sealing panel in contact with an inner surface of the can body. Heat-sealable materials are disposed on opposing surfaces of the sealing panel and can body. The sealing panels of the end closures are attached to the can body by heat seals. The heat seal for at least one of the end closures is discontinuous such that at least one vent channel extends through the heat seal so as to establish fluid communication between an interior of the composite container and the environment outside the composite container. The at least one vent channel is operable to vent excess gas pressure from the interior of the container.
1. A substantially paper-based composite container for an off-gassing product, comprising:
a can body comprising a tubular wall constructed from paperboard wrapped about an axis, the can body having opposite ends each defining an opening, the can body further comprising a substantially gas-impervious liner attached to an inner surface of the paperboard of the can body; and
a pair of substantially paper-based end closures attached to the opposite ends of the can body, each end closure defining a cylindrical sealing panel in contact with a surface of the can body, a heat seal material being disposed on a surface of the sealing panel and a heat seal material being disposed on the surface of the can body contacted by the sealing panel;
the sealing panels of the end closures being attached to the can body by heat seals;
the heat seal for at least one of the end closures being formed as a plurality of separate, spaced heat seal regions between the sealing panel and can body, and there being an unsealed region between each pair of adjacent spaced heat seal regions in which there is heat seal material on the sealing panel and on the surface of the can body contacted by the sealing panel but in which said heat seal materials are not sealed together such that each unsealed region constitutes a vent channel between the sealing panel and the can body so as to establish fluid communication between an interior of the composite container and the environment outside the composite container, the vent channel(s) being operable to vent excess gas pressure from the interior of the container.
2. The substantially paper-based composite container of claim 1 , wherein the spaced heat seal regions are spaced apart in a circumferential direction about the can body, the vent channel(s) extending generally axially of the can body.
3. The substantially paper-based composite container of claim 2 , wherein there are a plurality of vent channels circumferentially spaced apart.
4. The substantially paper-based composite container of claim 1 , wherein the end closures comprise a paperboard layer and a heat-sealable layer providing the heat seal material.