Method for producing an easily openable tightly sealed bag
AssigneeAsahi Chemical Polyflex Ltd.
InventorsHisao Kai, Kiyoshi Nakashima
Life of this patent
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Abstract
A process for producing a tightly sealed bag that can be easily opened by tearing at an edge thereof. According to the process a multiplicity of through cuts are formed along a line in a laminate film having at least one substrate layer and at least one heat seal layer. The laminate film is formed into an open bag with the line of through cuts provided along an edge to be sealed of the bag and edges of the open bag are heat sealed to form a sealed bag. In an alternative embodiment of the process, a multiplicity of through cuts are formed along a line in a substrate film and a heat seal film is laminated to the substrate film provided with the through cuts to form a laminate film prior to forming the sealed bag.
Claims10
A method of producing a tightly sealed bag that can be easily opened by tearing at a plurality of desired locations along an edge thereof comprising:
- providing a laminate film having a substrate layer and a heat seal layer, said heat seal layer having a tensile strength smaller than that of said substrate layer and a tear strength greater than that of said substrate layer;
- forming a multiplicity of elongated through cuts along a line in the laminate film, each of said through cuts being substantially parallel to each other and substantially perpendicular to the direction of said line;
- forming an open bag from the laminate film with said heat seal layer being disposed between two of said substrate layer and with the line of through cuts being provided parallel to an edge to be sealed of the bag whereby said through cuts are disposed substantially perpendicular to and substantially in said edge;
- and
- heat sealing edges of the open bag to form a sealed bag with a significant amount of said through cuts being wholly or partially filled by said heat seal layer in such a manner that the heat seal layer penetrates into the through cuts and closes said through cuts.
A method of producing a tightly sealed bag that can be easily opened by tearing at any desired location along an edge thereof comprising:
- providing a substrate layer;
- forming a multiplicity of elongated through cuts along a line in said substrate layer, each of said through cuts being substantially parallel to each other and substantially perpendicular to the direction of said line;
- superimposing and binding a heat seal layer on said substrate layer provided with the through cuts to form a laminate film, said heat seal layer having a tensile strength smaller than that of said substrate layer and a tear strength greater than that of said substrate layer;
- forming an open bag from the laminate film with said heat seal layer being disposed between two of said substrate layer and with the line of through cuts being provided parallel to an edge to be sealed of the bag whereby said through cuts are disposed substantially perpendicular to and substantially in said edge;
- and
- heat sealing edges of the open bag to form a sealed bag with a significant amount of said through cuts being wholly or partially filled by said heat seal layer in such a manner that the heat seal layer penetrates into the through cuts and closes said through cuts.
Dependencies are inferred from the claim text.