Sonoco Products Company

Jerry F Sansbury

Wade D Fletcher

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.

Composite container with balloon fold

A composite container comprising a tubular body formed of spirally wound plies of paperboard or the like and an internal vacuum accommodating liner substantially coextensive with the length of the tubular body and adhesively affixed solely at the opposed ends thereof to the tubular body. The container is completed by the mounting of opposed end caps which are hermetically sealed to the adhesively secured opposed ends of the liner for the accommodation of an internally developed vacuum within the liner. Formation of the tubular body and liner is effected utilizing conventional spiral winding equipment and involves (1) spirally forming a continuous liner with wide bands of adhesive spaced to correspond generally to the length of tube desired, (2) spirally forming a continuous length of composite tubing about the liner, the liner bonding peripherally to the tubing at the adhesive bands, and (3) severing the continuous tubing at a point generally centrally of each adhesive band whereby each formed tube will have the liner thereof adhesively secured solely at the opposite ends.

Method of constructing composite containers

Composite container construction

A pair of laterally spaced pocketed starwheels, mounted on a common shaft for synchronized rotation, receive and cradle composite fiber cans in a manner so as to preclude distortion of the cans upon movement past a capping station wherein the edge of each can engages an aligned flexible lid which is wiped onto the can end as the end is drawn past an inclined plate by continued movement of the can. A shaft mounted backing plate, laterally spaced from the outermost starwheel, stabilizes the can during the lid mounting operation.

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Hartsville, SC, United States of America

Jerry F Sansbury