Composite film, method for producing a composite film and a film composite consisting of at least one composite film, and apparatus for producing a composite film
The invention relates to a composite film ( 10 ), in particular for packaging ( 1 ) in the food industry, having at least one sealing layer ( 12 ), which consists of sealable material and is connected, at least indirectly, to a first layer ( 11 ) which acts as an outer layer, wherein the sealing layer ( 12 ) has a lower melting point than the first layer ( 11 ). According to the invention, it is provided that, on that side of the sealing layer ( 12 ) which is directed away from the first layer ( 11 ), a second layer ( 13 ), which acts as an inner layer, is arranged in operative connection with the sealing layer ( 12 ), that the second layer ( 13 ) has a higher melting point than the sealing layer ( 12 ), and that the second layer ( 13 ) has at least one through-opening ( 17; 17 a to 17 c ), which is covered over by the sealing layer ( 12 ).
1. A composite film ( 10 ), having at least one sealing layer ( 12 ), which consists of sealable material and is connected, at least indirectly, to a first layer ( 11 ) which acts as an outer layer, wherein the sealing layer ( 12 ) has a lower melting point than the first layer ( 11 ), wherein on that side of the sealing layer ( 12 ) which is directed away from the first layer ( 11 ), a second layer ( 13 ), which acts as an inner layer, is arranged in operative connection with said sealing layer ( 12 ), in that the second layer ( 13 ) has a higher melting point than said sealing layer ( 12 ), wherein a plurality of through-openings ( 17 ; 17 a to 17 c ) is configured in the second layer ( 13 ), the through-openings being arranged evenly spaced in relation to each other, wherein at least two rows of through-openings ( 17 , 17 a to 17 c ) are provided, in that a strip-like zone ( 19 ) without any through-openings ( 17 ; 17 a to 17 c ) is formed between the rows, the composite film ( 10 ) forming a folding edge such that the through-openings ( 17 ; 17 a to 17 c ) of the second layer ( 13 ) laid against each other are arranged relative to one another in an overlapping manner and aligned, and wherein said second layer ( 13 ) has at least one through-opening ( 17 ; 17 a to 17 c ) which is covered over by said sealing layer ( 12 ).
2. The composite film according to claim 1 , characterized in that the second layer ( 13 ) consists of polyethylene terephthalate (PET).
3. The composite film according to claim 1 , characterized in that at least one third layer ( 15 ) acting as a barrier layer is arranged between the sealing layer ( 12 ) and the first layer ( 11 ).
4. The composite film according to claim 1 , characterized in that the sealing layer ( 12 ) consists of polyethylene (PE) and has a layer thickness of 30 μm to 100 μm, and in that the second layer ( 13 ) has a thickness of 8 μm to 20 μm.
5. The composite film according to claim 1 , characterized in that the sealing layer ( 12 ) consists of polyethylene (PE) and has a layer thickness of between 50 μm and 90 μm and in that the second layer ( 13 ) has a thickness of between 12 μm and 18 μm.
6. The composite film according to claim 1 , wherein the sealing layer joins through the aligned through-openings to form a bond.
7. A method for producing a film composite ( 1 ) consisting of at least one composite film ( 10 ) according to claim 1 , the method comprising:
aligning the at least two rows of through-openings of the second layer; and activating the at least one sealing layer by introducing heat and pressure, whereby the introduction of the heat and pressure causes a displacement of a material of the at least one sealing layer into a region of the aligned through-openings such that the material of the at least one sealing layer comes mutually into operative connection.