Apparatus for making tear resistant separable end-connected bags
AssigneeUnion Carbide Corporation
InventorsCharles R. Walitalo, Alvin E. Ericson
Life of this patent
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Abstract
Continuous strip closed-bottom open-mouthed packaging bags are produced by continually making, at spaced intervals in a continuous flattened tubular oriented plastic film supply, a transversely extending heat seal to define a bag bottom, and, adjacent each heat seal, perforating the two plies of the film supply with a blade heated to effect annealing of the edges of the perforations and having a serrated cutting edge with spaced deep recesses to define connecting tabs between perforations.
Claims2
Apparatus for forming discontinuous annealed edged perforations separated by tabs in flexible plastic film sheet material comprising, in combination, a serrated edged cutting blade having recesses disposed at spaced intervals extending into the blade from its cutting edge to beyond its cutting edge, said recesses being disposed at the apexes of crevices in the serrated edge of the blade, and means to heat the blade to a preselected temperature lower than the melting temperature of the plastic film sheet material in process, at which temperature the material will anneal.
Dependencies are inferred from the claim text.