Method for manufacturing a plastic fabric-film composite product, plastic fabric-film composite and packaging bag comprising a plastic fabric-film composite

Abstract

A method for manufacturing a plastic fabric-film composite product includes forming an extruded-film web with at least one sealing layer by film extrusion in such a way that the sealing layer is located on a first side of the extruded-film web and then, feeding and laminating a plastic-fabric web made of film-strip fabric and the prefabricated extruded-film strip with one another to form a composite web. The composite web is formed in such a way that a second side of the extruded-film web faces a first side of the plastic-fabric web.

Claims

1. A plastic fabric-film composite product comprising: an extruded-film web that has been coextruded in multiple layers, wherein one layer of the multiple layers comprises a sealing layer on a first side of the extruded film web that forms an outer side of the extruded-film web, and a plastic-fabric web formed of a film-strip fabric, the plastic-fabric web being connected via a first side of the plastic-fabric web to a second side of the extruded film web via an at least single-layered lamination layer, wherein the film-strip fabric comprises plastic strips that are interwoven so as to cross over one another.

2. The plastic fabric-film composite product as recited in claim 1, wherein the coextruded extruded-film web has at least three layers and comprises a barrier layer based on ethylene-vinyl alcohol copolymer (EVOH) or polyamide (PA) and adjoins the sealing layer via a primer layer.

3. The plastic fabric-film composite product as recited in claim 1, wherein the extruded-film web comprises at least one barrier layer in addition to the sealing layer.

4. The plastic fabric-film composite product as recited in claim 1, further comprising a cover film provided with an imprint on a print side, the cover film being laminated with the plastic-fabric web so that the print side of the cover film faces a second side of the plastic-fabric web.

5. The plastic fabric-film composite product as recited in claim 1, wherein the plastic-fabric web has a mass per unit area of between 40 g/m.sup.2 and 80 g/m.sup.2 and the extruded-film web has a thickness of between 25 μm and 90 μm, and wherein the lamination layer has a thickness between 10 μm and 50 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the invention will become apparent from the description of embodiments that follows, with reference to the attached figures, wherein:

(2) FIG. 1 is a schematic representation of a system for manufacturing a plastic fabric-film composite product, according to the invention;

(3) FIG. 2 depicts a layered design for an embodiment of a plastic fabric-film composite according to the invention;

(4) FIG. 3 depicts a layered design for an alternative embodiment of a plastic fabric-film composite according to the invention; and

(5) FIG. 4 depicts a layered design for an alternative embodiment of a plastic fabric-film composite according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(6) The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims.

(7) FIG. 1 shows, in a purely schematic representation, a system for manufacturing a plastic fabric-film composite product, wherein the steps of the method according to the invention are to be described with reference to the system. FIGS. 2 and 3 reflect an exemplary layered designs of the plastic fabric-film composite.

(8) In order to manufacture the plastic fabric-film composite product, an extruded-film web comprising at least one sealing layer 1 is formed as a blown-film web 2 using blown-film extrusion, such that a sealing layer 1 is located on a first side of the blown-film web 2. As shown in FIGS. 2 and 3, the blown-film web is preferably coextruded in multiple layers. During the production of the blown-film web 2, the web is initially expanded immediately after extrusion and is then laid flat, in a cooled state, according to known methods. A bubble formed by the blown-film web 2 is cut open in this case. After the blown-film web 2 is produced, the web is initially rolled onto rolls 3, which are only schematially indicated in FIG. 1. The blown-film web 2 is then withdrawn from the rolls 3 for further processing.

(9) To simplify the representation, FIG. 1 shows a variant in which the cooled and laid-flat blown-film web 2 is immediately fed to a further processing, even though the web is initially rolled up and unrolled in practical use. With respect to the blown-film extrusion, a conventional blown-film system 4 is schematically indicated in FIG. 1.

(10) The prefabricated blown-film web 2, after having been manufactured and preferably after having been stored on a roll 3, is fed together with a plastic-fabric web 5, wherein the blown-film web 2 and the plastic-fabric web 5 are connected, by extrusion lamination, via a molten lamination layer 6a in the gap between a roller pair 7.

(11) As described in greater detail in the following, the blown-film web 2 and the plastic-fabric web 5 are laminated with each other in such a way that the sealing layer 1 forms an outer layer of the composite web 8 on a first side of the blown-film web 2, while the blown-film web 2 is connected, at a second side, to the plastic-fabric web 5 via the lamination layer 6a.

(12) In the exemplary embodiment according to FIG. 1, the plastic-fabric web 5 is rolled off a roll 3′. In this case, it can already be provided that the plastic-fabric web 5 has already been laminated with a cover film 9, which is situated on the composite web 8 on the outside, opposite the sealing layer 1.

(13) FIG. 2 shows a preferred layered design of the plastic fabric-film composite formed in the method according to FIG. 1 comprising the composite web 8.

(14) The plastic-fabric web 5 is formed from a film-strip fabric, wherein this fabric can have a mass per unit area, for example, between 50 g/m.sup.2 and 70 g/m.sup.2. The individual film strips, which are not represented further in the figures, are generally interwoven from stretched polypropylene having a width of typically approximately 3 mm in a vertical orientation.

(15) According to the invention, the plastic fabric-film composite comprises a blown-film web 2 which, in the exemplary embodiment represented, is coextruded in three layers. A functional layer in the form of a barrier layer 11 adjoins the sealing layer 1, which is located on the outside in the composite web 8, via a primer layer 10a. The total thickness of the blown-film web 2 is typically between 30 μm and 80 μm, wherein EVOH and PA, in particular, are possible options as the material for the barrier layer 11, and polyolefins, in particular polyethylene, is a possible option for the sealing layer 1.

(16) As shown in FIG. 2, the lamination layer 6a is in the form of two layers and adjoins the barrier layer 11 of the blown-film web 2 via a primer layer 10b and adjoins the plastic-fabric web 5 via a connecting layer 12a comprising polypropylene. The thickness of the lamination layer 6a is typically between 15 μm and 40 μm.

(17) The represented design of the blown-film web 2 comprising the sealing layer 1, the primer layer 10a, and the barrier layer 11 in the layer sequence PE/HV/PA or EVOH is presented merely by way of example. In particular, within the scope of the invention, blown-film webs 2 comprising more than three layers are easily formed. The layered designs PE/HV/EVOH/HV/PE, PE/HV/PA/HV/PE, PE/HV/PA/EVOH/PA/HV/PE, for example, also are suitable.

(18) FIG. 3 shows that the second side of the plastic-fabric web 5 situated at the top in the figures also can be laminated with a film, where the film then forms an outer cover film 9.

(19) Biaxially oriented polypropylene (BO-PP) and polyethylene terephthalate (PET) also are possible options for use as the material. The thickness of the cover film 9 is typically between 10 μm and 40 μm. The cover film 9 can be provided with an imprint 13 in the direction of the plastic-fabric web 5, which imprint is situated on the inside, in a protected manner, on the composite web 8 that is formed.

(20) The cover film 9 and the plastic-fabric web 5 are preferably connected to each other by extrusion lamination, for which a further lamination layer 6b is provided. As is similarly the case with the above-described lamination layer 6a, lamination layer 6b is designed having two layers, including a primer layer 10c and a connecting layer 12b.

(21) Packaging bags can be formed from the plastic fabric-film composite, in the case of which the sealing layer 1 is located on an inner side of the bag. It is then also possible to heat-seal such a bag, wherein at least one connecting seam is formed on the sealing layer 1 by a heat-sealed seam without the structure of the film-strip fabric being adversely affected there.

(22) For example, in the case of a side-gusseted bag, a back-side seam extending along the length of the bag is formed by hot air. A head and a base of the film bag is formed by heat-sealing, if necessary, wherein a stepped trimming of the front walls and of the side gussets are possible options for improving the closure.

(23) Proceeding from the plastic-fabric web according to FIG. 3, FIG. 4 shows a five-layered design of the blown-film web 2. The sealing layer 1 located on the outside in the composite web 8 is produced from polyethylene and has a layer thickness of 22 μm. A 6 μm-thick layer comprising EVOH adjoins the sealing layer 1 via a primer layer 10a having a layer thickness of 5 μm. A further polyethylene layer having a thickness of 22 μm is adjoined via a further 5 μm-thick primer layer 10d. The entire blown-film web 2 therefore has a layer thickness of 60 μm.

(24) The blown-film web 2 is connected to the plastic-fabric web 5 via a lamination layer 6a. The lamination layer 6a consists of a connecting layer 12a, which preferably consists of polyethylene or a blend of polypropylene and polyethylene, and a primer layer 10b comprising Lotader®—a terpolymer. The connecting layer 12a preferably has a thickness of 28 μm, and the primer layer 10b has a thickness of 7 μm. The lamination layer 6a also adjoins the polyethylene layer 14 of the blown-film web 2 via the primer layer 10b and adjoins the plastic-fabric web 5 via the connecting layer 12a. In the example shown, the cover film 9 is preferably produced from polyethylene or oriented polypropylene (OPP) and typically has a thickness between 18 μm and 20 μm. The cover film 9 also is connected to the plastic-fabric web 5 via the lamination layer 6b, wherein the lamination layer 6b is either designed identically to the lamination layer 6a or has a layered design corresponding to one of the preceding examples.

(25) As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that.