Heat sealed paperboard carton having polymer coating on one side only
AssigneeWestvaco Corporation
InventorsBarry G. Calvert, Walter H. Donnellan
Life of this patent
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Abstract
Folded paperboard food cartons having a polymer coating only on the interior surface and sales graphics on a substantially unplasticized clay coated exterior surface are heat sealed at contiguous areas of overlapping flaps wherein the polymer coated interior surface is in direct contact with a small portion of the clay coated exterior surface or, where it is desired to secure together two portions of the clay coated exterior surface. In such heat sealing areas, small and accurately located exterior clay coated carton surface areas are primed with a water based polymer emulsion such as ethylene vinyl acetate that is precisely applied to such areas by a printing press.
Claims12
A composite material package blank formed from a paperboard sheet having a coating of hot, viscous, thermoplastic polymer film applied to an inside surface thereof, an outside surface of said paperboard sheet having selectively positioned areas of press applied graphics and water soluble polymer emulsion applied thereto whereby an internal volume of a package erected from said blank is closed by an integral cover portion of said sheet and at least partially sealed by fuse bonds between said inside surface coating of polymer film on said integral cover portion and said selectively positioned areas of polymer emulsion on said outside surface.
A folded paperboard package having interior and exterior surfaces, said interior surfaces having a coating of thermoplastic film applied thereto as a substantially continuous, hot, viscous curtain, said exterior surface having a uniformly calendered coating of mineral particulates supporting respective areas of press applied graphics and water soluble polymer emulsion, a vessel portion of said package having an interior volume closed by a cover portion, said cover portion and vessel portion being distinct portions of the same paperboard structure separated by an integral hinge score, said cover portion being secured at an interior volume closure position by a fuse bond between said areas of press applied water soluble polymer emulsion and said interior surface film.
Dependencies are inferred from the claim text.