초록 ▼

A plastic packaging material which, when formed as a package having seams, will provide a predictable line of failure along a seam when the package is opened to prevent the package from tearing down the side. The predictable failure path is provided through a lamination process involving specific re

A plastic packaging material which, when formed as a package having seams, will provide a predictable line of failure along a seam when the package is opened to prevent the package from tearing down the side. The predictable failure path is provided through a lamination process involving specific resins or blends of resins laminated in three (or more) layers in which an extruded inner layer forms a weak inner bond wholly within that inner layer to create the predictable line of failure and in which the process of forming the material does not inhibit processing speed, efficiency, and economics of materials used to provide this reliable openability.

대표청구항 ▼

[What is claimed is:] [1.]an inner film layer;a three layer extrudate of:first and second outer extrudate layers of polyethylene film material having a density of about 0.914 to about 0.926 and a melt index of 3.5 to 17.0;a third extrudate layer of plastic material having a core weight of 1.0 pounds

[What is claimed is:] [1.]an inner film layer;a three layer extrudate of:first and second outer extrudate layers of polyethylene film material having a density of about 0.914 to about 0.926 and a melt index of 3.5 to 17.0;a third extrudate layer of plastic material having a core weight of 1.0 pounds per ream or more laminated between and bonded to said first and second outer extrudate film layers, said third extrudate layer forming inner plies with the first and second extrudate layers and having characteristics such that a line of weakness is formed wholly within the extrudate that tears easier than the first and second outer layers and forms a substantially predictable line of failure wholly within the plastic extrudate material, the line of failure occurring when opening said package by applying a separating force to the sealed seam, and wherein the extrudate's inner plies are not exposed to air and have an adhesive level of 20 to 50 gms/in; andan outer film layer.