Mobil Oil Corporation

Tenneco Plastics Company

Pactiv Corporation

Earle R Powell

Gerald E Rawlings

Carl R Letendre

A thermoplastic bag structure and a method for forming handle-containing bags in roll-form. The method includes the steps of forming a continuous collapsed tube; forming pairs of closely spaced seals transverse to the tube at bag length distances apart; forming a transverse line of weakness between each pair of seals; simultaneously or thereafter folding the marginal edges of the tube inwardly toward each other; forming and removing a cut-out region at one end of each sealed segment of the tube so that on removal of the cut-out region, the cut defines loop handles and a bag mouth region in each bag; again folding the marginal edges of the tube inwardly toward each other; and convolutely winding the structure to form severable bags on a roll.

Integral handled layflat thermoplastic bag

An improved thermoplastic film heat bonding apparatus includes a heated seal bar, a support member supporting the heated seal bar for reciprocating motion against a platen and a resilient coupling between the support member and the heated seal bar to allow deflection of the heated seal bar with respect to the support member providing better conformance between the platen and the face of the seal bar contacting the platen for more uniform and repeatable heat seals. Springs are used to provide the resilient coupling between the support member and the heated seal bar. One mounting providing both resilient coupling and continuous adjustable spacing between the support member and the heated seal bar includes a bracket supporting a threaded member passed through the support member and a coil spring biasing the bracket and support member apart. The bracket is itself resiliently mounted to the heated seal bar also by compression coil springs. Further contributing to improved registration between the heated seal bars and the platen is a flexible, cantilever mounting of the platen. The heated seal bar support member is mounted on a support arm rotationally mounted at one end and biased against a cam at an opposing end. Rotation of the cam pivots the support arm back and forth reciprocating the support member and heated seal bar against the platen.

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Jacksonville, IL, United States of America

Earle R Powell