Importance

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Abstract

A composite container capable of accommodating an internal vacuum environment within a tubular body of spirally wound paperboard or similar paperbase materials. A hermetically sealed liner is provided coextensive with the interior of the tubular body and adhesively secured thereto throughout substantially the full extent of the interior surface of the body. The liner is spirally wound, defining a spiral overlapped seam with the overlapping edge portion including an underfolded edge flap folded about a fold line prior to adhesive engagement with the overlapped edge portion. The seam fold thus formed has the interior thereof in direct communication with the paperbase body and is capable of ballooning inward, through the entire length thereof, upon generation of a vacuum atmosphere with the container. The vacuum atmosphere can thus be accommodated without affecting the structural integrity of the container. Lines of weakness are specifically avoided in the body plies by staggering the ply seams, offsetting the ply seams from the liner balloon seam, and providing at least some of the body plies with overlapped deckled or skived edges.

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First Claim