Reinforced thin film for flexible packaging

Abstract

The invention provides a thermoplastic film comprising: a base film wherein the base film comprises a stretchable polyolefin material comprising one or more layers; and a plurality of extruded fibre elements; wherein the extruded fibre elements are located on at least one surface of the base film; wherein the extruded fibres form one or more protrusions relative to the plane of the base film; wherein at the location where the fibre elements are provided on the base film, a domain of a material mixture comprising the base film material and the fibre material is present between a domain of pure base film material and a domain of pure fibre material, and wherein the average thickness of the base film is less than the average thickness of the protrusion.

1 . A thermoplastic film comprising:
 a base film wherein the base film comprises a stretchable polyolefin material comprising one or more layers; and   a plurality of extruded fibre elements;   wherein the extruded fibre elements are located on at least one surface of the base film;   wherein the extruded fibre elements form one or more protrusions relative to the plane of the base film;   wherein at the location where the fibre elements are provided on the base film, a domain of a material mixture comprising the base film material and the fibre material is present between a domain of pure base film material and a domain of pure fibre material,   wherein the average thickness of the base film is less than the average thickness of the protrusion; and   wherein the fibre elements cover less that 51% of the surface area of the film.   
     
     
         2 . The thermoplastic film according to  claim 1 , wherein the ratio of the average width to the average length of said elements of the current invention is in a range selected from the group consisting of: 1:500-1:10,000,000 and 1:50-1:500,000. 
     
     
         3 . The thermoplastic film according to  claim 1 , wherein the average diameter of the fibre elements is in a range selected from the group consisting of: between 30 μm and 500 μm, between 50 μm and 300 μm, and between 75 pm and 150 pm. 
     
     
         4 . The thermoplastic film according to  claim 1 , wherein the number of fibre elements extruded on the base film is selected from the group consisting of: at least three fibre elements and at least eight fibre elements. 
     
     
         5 . The thermoplastic film according to  claim 1 , wherein each of said fibre elements covers an area of the base film selected from the group consisting of: more than 4.5 mm 2 , more than 6.0 mm 2 , and more than 8.0 mm 2 . 
     
     
         6 . The thermoplastic film according to  claim 1 , wherein the maximum average diameter of the fibre elements does not vary from the minimum average diameter of the fibres by a percentage selected from the group consisting of: more than 75%, more than 50%, more than 25%, and more than 10%. 
     
     
         7 .- 10 . (canceled) 
     
     
         11 . The thermoplastic film according to  claim 1 , wherein the ratio of the width to the height of the fibre elements is in a range selected from the group consisting of: 3:1 to 1:3, 2:1 to 1:2, and 1.5:1 to 1:1.5. 
     
     
         12 . (canceled) 
     
     
         13 . The thermoplastic film according to  claim 1 , wherein the average thickness of the base film is in a range selected from the group consisting of: 4 μm to 50 μm, 5 μm to 30 μm, and 6 μm to 25 μm. 
     
     
         14 . The thermoplastic film according to  claim 1 , wherein the fibres elements protrude above the plane of the surface of the base film on average in a range selected from the group consisting of: between 30 μm and 500 μm, between 50 μm and 300 μm, and between 75 μm and 150 μm. 
     
     
         15 . The thermoplastic film according to  claim 1 , wherein the base film and the fibre elements are prestretched by a percentage selected from the group consisting of: at least 10%, at least 50%, at least 100%, and at least 200%. 
     
     
         16 .- 19 . (canceled) 
     
     
         20 . The thermoplastic film of  claim 1 , wherein the thermoplastic film is provided on a roll. 
     
     
         21 .- 26 . (canceled) 
     
     
         27 . The thermoplastic film according to  claim 1 , wherein the fibre elements have an oval or elliptical cross section with a ratio of average width to average height of less than 10:1. 
     
     
         28 . The thermoplastic film according to  claim 1 , wherein the fibre elements have an oval or elliptical cross section and have a basis weight of less than 1 gr/cm 2 . 
     
     
         29 . The thermoplastic film according to  claim 1 , wherein the fibre elements have an oval or elliptical cross section with a ratio of average width to average height of less than 10:1 and have a basis weight of less than 1 gr/cm 2 . 
     
     
         30 . The thermoplastic film according to  claim 1 , wherein the base film and the fibre elements are independently selected from the group consisting of polyethylene, polypropylene, polyisobutylene, polybutyl-1-ene, poly-4-methylpent-1-ene, polyisoprene, polybutadiene and mixtures and copolymers thereof. 
     
     
         31 . The thermoplastic film according to  claim 1 , wherein the base film has an ABC, ABA, ABCBA or ABCDE structure, wherein ABCDE are layers having different compositions and/or thicknesses, with the exception that layer D may be the same as layer B. 
     
     
         32 . The thermoplastic film according to  claim 1 , wherein the outer layer A has a lower density and/or crystallization temperature than an adjacent layer of the base film. 
     
     
         33 . The thermoplastic film according to  claim 1 , wherein said thermoplastic film is perforated. 
     
     
         34 . A method of producing a thermoplastic film comprising:
 (i) extruding a base film comprising a stretchable polyolefin material comprising one or more layers;   (ii) extruding a plurality of fibre elements;   (iii) applying the plurality of fibre elements to at least one side of the base film, and   (iv) bonding the fibre elements to the base film;   wherein the fiber elements are extruded directly onto the base film; wherein the extruded fibres form one or more protrusions relative to the plane of the base film;   wherein at the location where the fibre elements are provided on the base film, a domain of a material mixture comprising the base film material and the fibre material is present between a domain of pure base film material and a domain of pure fibre material, such that at least a portion of each fibre element forms an interfacial mixture with the base film and wherein the average thickness of the base film is less than the average thickness of the protrusion;   wherein the fibres cover less than 51% of the surface area of the film.   
     
     
         35 . The thermoplastic film product of  claim 33 , wherein the thermoplastic film is provided on a roll.