Method and device for closing and sealing gable shaped folding cartons
AssigneeNimco Corporation
InventorGeorge L. Bachner
Life of this patent
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Abstract
Apparatus and method for forming sealed joints, including a pouring lip sanitarily protected therein, by welding layers of thermoplastic coated paperboard together. Paperboard layers are pressed together by jaws, with relieved areas where excessive pressure would render pouring lip less satisfactory, while or after heat is applied to said paperboard layers. The apparatus and method is particularly useful for forming sealed joints for paperboard cartons, such as milk cartons.
Claims12
In an apparatus for sealing a package having a gable shaped closure, the gable shaped closure having marginal areas forming a sealing truss, the apparatus having jaw means for applying force externally on said marginal areas while the temperature of said marginal areas is elevated to thereby seal the package, the improvement comprising jaw means having a pair of jaws with multiplanar surfaces, each of said jaws having a first planar surface for engaging a first thickness of package material, a second planar surface, recessed from the first planar surface, for engaging a second thickness of package material, a third planar surface, recessed from the second planar surface, for engaging a third thickness of package material, and a fourth planar surface, recessed from the third planar surface, for engaging the third thickness of package material, whereby less force is exerted on the third thickness of package material corresponding to relieved portions engaged by the fourth planar surface of the multiplanar surfaces of said jaw means.
In a method of forming a sealed joint in a container having thermoplastic coated surfaces by engaging the outer surface of a sealing truss with jaws and applying a sufficient amount of heat to melt the thermoplastic coating and weld the surfaces together, the sealing truss having a pouring spout folded therein, the improvement which comprises the use of jaws with multiplanar surfaces, each of said jaws having a planar surface for engaging a first thickness of package material, a second planar surface, recessed from the first planar surface, for engaging a second thickness of package material, a third planar surface, recessed from the second planar surface, for engaging a third thickness of package material, and a fourth planar surface, recessed from the third planar surface, for engaging the third thickness of package material, whereby less force is exerted on the sealing truss in the area of the pouring spout compared with the remainder of the sealing truss so that the seal formed in the area of the pouring spout is less secure thereby facilitating the opening of the container to expose the pouring spout.
Dependencies are inferred from the claim text.