Easy opening shrink wrapper for product bundle

Abstract

A product bundle plastic film shrink wrapper and method of forming same is described. The shrink wrapper comprises a plastic film having shrink properties and formed from a blend having from about 5% to 10% polybutene-1. The plastic film forms a wrapper for the bundle by being shrunk wrapped about the bundle with a lap seal formed by overlapped film end portions of the film in a section of the wrapper. The polybutene-1 provides for the lap seal to have a shear force sufficient to hold the product bundle together and low peel force to permit separation of the overlapped film portion by sliding fingers of a user's hand in an unsealed gap of the lap seal and sliding the fingers along the lap seal whereby to easily remove the wrapper from the product bundle.

1 . A product bundle plastic film shrink wrapper comprising a plastic film having shrink properties and formed from a blend having from about 5% to 10% polybutene-1, said plastic film forming a wrapper for said bundle by being shrunk wrapped about said bundle with a lap seal formed by overlapped film end portions of said plastic film in a section of said wrapper, said polybutene-1 providing for said lap seal to have a shear force sufficient to hold the product bundle together and sufficient to permit separation of said overlapped film portion by sliding a separation means between said overlapped film end portions to separate said lap seal whereby to easily remove said wrapper from said product bundle. 
     
     
         2 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said lap seal is further provided with an unsealed gap to provide for the insertion of said separation means. 
     
     
         3 . A product bundle plastic film wrapper as claimed in  claim 2  wherein said separation means is constituted by the fingers of a person's hand to be inserted in said gap and slid along said lap seal to separate said seal of said overlapped film end portion. 
     
     
         4 . A product bundle plastic film wrapper as claimed in  claim 2  wherein said unsealed gap is formed by a release varnish disposed over said plastic film and extending transversely of said overlapped film end portions. 
     
     
         5 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said product bundle is a bundle of asphalt shingles. 
     
     
         6 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said plastic film is a multi-layered blend of LDPE (Low Density Polyethylene), LLDPE (Linear Low Density Polyethylene) and said polybutene-1 as an inner layer. 
     
     
         7 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said plastic film is a mono layer of polyethylene blended with said polybutene-1. 
     
     
         8 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said plastic film has a thickness of from about 1.75 mil to about 3 mil. 
     
     
         9 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said lap seal has a low peel force of less than 6 lbs for a one inch wide lap seal and preferably 1.6 lbs. 
     
     
         10 . A product bundle plastic film wrapper as claimed in  claim 4  wherein said release varnish is disposed over said plastic film of one of said overlapped film portions in the area of said lap seal to prevent sealing of said lap seal in the area of said varnish. 
     
     
         11 . A product bundle plastic film wrapper as claimed in  claim 4  wherein said unsealed gap is 2 to 3 inches wide. 
     
     
         12 . A product bundle plastic film wrapper as claimed in  claim 1  wherein said plastic film is a clear plastic film having printed matter thereon and a clear window area for product viewing. 
     
     
         13 . A method of forming a plastic film shrink wrap about a product bundle comprising the steps of:
 i) wrapping said product bundle with a plastic film having shrink properties and formed from a blend having therein from about 5% to 10% polybutene-1, said film having overlapped film end portions on an underside thereof;   ii) subjecting said wrapped bundle to a heat environment to shrink said plastic film about said product bundle, said overlapped film end portions of said film forming a lap seal when subjected to said heat environment, said polybutene-1 in said blend creating said lap seal to have a shear force sufficient to hold said product bundle together and a low peel force to permit separation of said lap seal by sliding a separation means between said overlapped film end portions whereby to separate said lap seal to easily remove said shrink wrap from said product bundle.   
     
     
         14 . A method as claimed in  claim 13  wherein there is further provided the step of applying a strip of a release substance coating across one of said overlapped film end portions prior to step (ii) to form an unsealed gap in said lap seal to provide for the insertion of said separation means in said gap and to slide same along said lap seal to separate said overlapped film end portions or a section thereof. 
     
     
         15 . A method as claimed in  claim 14  wherein said separation means is constituted by the fingers of a person's hand inserted into said unsealed gap and slid along said lap seal to separate said overlapped film end portions, said product bundle being a rectangular asphalt shingles bundle, said lap seal extending longitudinally on an underside of said bundle. 
     
     
         16 . A method as claimed in  claim 14  wherein said plastic film is a clear plastic film, and wherein there is further provided the step of printing a color and/or matter on said clear plastic film while leaving a clear film window area for product viewing. 
     
     
         17 . A method as claimed in  claim 13  wherein said plastic film is a mono layer or multilayer blown film or cast film formed from a blend of LDPE (Low Density Polyethylene) and LLDPE (Linear Low Density Polyethylene) and a polybutene-1 polymer on an inner surface thereof to cause said lap seal to form an easy-to-open seal when subjected to said step (ii).