One-hand quick-opening closure device for sealed bags made of plastic material or paper

Abstract

A quick-opening closure device for sealed bags is described. The device can be opened and used by one hand, as the mouth of the bag is torn by the compression made by two fingers of a user by bending two juxtaposed sheets.

1 . A quick-opening closure device for sealed bags made of paper or plastic material, the closure device comprising
 two straight or curved flexible sheets having an elongated shape, with a sheet length much greater than a sheet width or sheet thickness, the sheets having sheet sections of variable or even constant shape,   said sheets being sealed to a border region of a mouth of the bag and being juxtaposed and parallel to each other with the bag in a closed condition,   said sheets being moveable apart from each other by bending outwardly when a compression is exerted, said bending causing the bag to be quickly opened by a tearing action by way of the two sheets at the paper or plastic border region closing the bag.   
     
     
         2 . The device according to  claim 1 , wherein the two flexible sheets are pre-bent such that once juxtaposed, with sheet faces in contact on a plane when the bag is closed, stresses are generated inside the paper or plastic material of the sheets, said stresses moving apart central areas of the two flexible sheets to tear the mouth of the bag when a manual compression is applied on distal ends of the flexible sheets. 
     
     
         3 . The device according to  claim 1 , wherein each one of the two flexible sheets has a surface or plane to be juxtaposed against a respective surface or plane of the other sheet, said sheets contacting each other while having a greater thickness in their central area and a smaller thickness at their distal ends such that, in absence of inner structural stresses of the material, neutral plane of the sheets is farther from their common flat surface in the central area that in the distal ends, in order to generate an initial outwardly bending moment when the compression force is applied between their distal ends. 
     
     
         4 . The device according to  claim 1 , wherein each one of the two sheets has a groove perpendicular to a sheet length, said groove being located on a side opposite to the side than that where the border region of the mouth of the bag is sealed each groove is being placed at a same distance from a common center of the sheets such that, when the sheets are compressed, the sheets bend tearing the border region of the bag generating a parallelogram shaped aperture. 
     
     
         5 . The device according to  claim 1 , wherein the two sheets are joined together, each one at one of its distal ends by a short thin film made of the same material of the sheets, such that the sheets can be juxtaposed when are folded by 180° one against the other. 
     
     
         6 . The device according to  claim 1 , wherein the sheet sections have a triangle shape, the sheets being sealed to the border region of the mouth of the bag on a side of said triangle. 
     
     
         7 . The device according to claim the sheet sections have a right trapezoid shape, the sheets being sealed to the border region of the mouth of the bag on one of the parallel sides of the trapezoid. 
     
     
         8 . The device according to  claim 1 , wherein bag walls are made of layers of different materials. 
     
     
         9 . The device according to  claim 1 , wherein an inner bag wall material is a material suitable for for food, pharmaceutical or industrial use. 
     
     
         10 . The device according to  claim 1 , wherein the sealing occurs by glueing, welding or application of a “stick-no-stick” adhesive to the border region of the mouth of the bag.