Plastic fabric composite, packaging bag made of a plastic fabric composite, and a method for manufacturing a packaging bag

Abstract

A plastic fabric composite for a plastic fabric composite bag has a strip fabric, an outer film, a plastic intermediate layer disposed between the outer film and the strip fabric, where a line of weakness in a form of a punching line is included, where the strip fabric is completely severed along the punching line, where the punching line ends in the intermediate layer and where the outer film is undamaged at the punching lines.

Claims

1. A plastic fabric composite for a plastic fabric composite bag, comprising: a strip fabric; an outer film; a plastic intermediate extrusion layer disposed between the outer film and the strip fabric; wherein a line of weakness in a form of a punching line extends through the strip fabric and terminates within the plastic intermediate extrusion layer; wherein the punching line enables the strip fabric to be completely severed along the punching line without damaging the outer film, wherein the outer film and the strip fabric are extrusion-laminated by molten plastic that forms the intermediate extrusion layer between the outer film and strip fabric, wherein the intermediate extrusion layer has a thickness between 20 m and 55 m and wherein the outer film has a lesser thickness than the intermediate extrusion layer.

2. The plastic fabric composite according to claim 1, wherein the outer film has a layer thickness in a range of between 10 m and 50 m and is selected from a material from the group consisting of polyethylene terephthalate (PET), polypropylene (PP) and biaxially oriented polypropylene (BO-PP).

3. The plastic fabric composite according to claim 1, wherein an adhesion-promoter layer with a thickness in a range between 1 m and 10 m is disposed between the intermediate extrusion layer and the outer film.

4. The plastic fabric composite according to claim 1, wherein the strip fabric is formed of strips of a stretched film and has a mass per unit area in a range of between 50 g/m.sup.2 and 120 g/m.sup.2.

5. A packaging bag made from a plastic fabric composite according to claim 1, wherein the packaging bag comprises two front walls, wherein the outer film forms a bag outer side and wherein the strip fabric forms a bag inner side.

6. The packaging bag according to claim 5, wherein the punching line forms a tear-open aid.

7. The packaging bag according to claim 6, wherein the punching line extends on one of the front walls in a manner of a frame and borders a section that is removable from the corresponding front wall.

8. A method for manufacturing a packaging bag, comprising the steps of: forming a plastic fabric composite web by feeding a web of an outer film and a web of a strip fabric and extrusion-laminating the outer film and the strip fabric with molten plastic, thereby forming an intermediate extrusion layer between the outer film web and the strip fabric web, wherein the intermediate extrusion layer has a thickness between 20 m and 55 m and wherein the outer film has a lesser thickness than the intermediate extrusion layer; and feeding the plastic fabric composite web through a punching device and forming lines of weakness in a form of punching lines at predefined intervals, between a punching roller and a mating roller so that the strip fabric is completely severed and such that the punching lines end in the intermediate extrusion layer such that the outer film remains undamaged; and forming individual packaging bags from sections of the plastic fabric composite web.

9. The method according to claim 8, wherein the lines of weakness are formed to extend across an entire width of the plastic fabric composite web.

10. The method according to claim 9, further comprising subsequently folding the plastic fabric composite web into a plastic fabric composite tube, closing the folded plastic fabric composite tube on a periphery and separating individual tube pieces from one another along the line of weakness.

11. The method according to claim 10, wherein the line of weakness has steps along its extension in the direction of the width of the plastic fabric composite web.

12. The method according to claim 11, wherein the individual packaging bags include front walls and wherein the subsequently folding comprises forming the plastic fabric composite tube with gussets in such a way that the steps are located at transitions from the gussets to the front walls.

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 depicts a web of a plastic fabric composite;

(3) FIG. 2 depicts a sectional illustration of the design of the plastic fabric composite;

(4) FIG. 3 depicts the plastic fabric composite according to FIG. 2, having a line of weakness in the form of a punching line;

(5) FIG. 4 depicts a blank of a packaging bag having gussets, which is formed from a section of the plastic fabric composite web according to FIG. 1;

(6) FIG. 5 depicts an alternative embodiment of a weakening line for forming a 10 removable section; and

(7) FIG. 6 depicts a section along line A-A of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) 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.

(9) FIG. 1 depicts a plastic fabric composite web, which has a line of weakness in the form of a punching line 1 that extends in the direction of the width at equal intervals. Proceeding from the plastic fabric composite web, a plastic fabric composite tube having gussets 2 is formed in the following by folding (for example, see FIG. 4), wherein the subsequent folded edges 3 are shown as dashed lines for facilitating the assignment. The punching line 1 has steps along its extension, in the direction of the width, wherein the steps are formed at the transitions from the gussets 2 to the opposing front walls 4a, 4b.

(10) As is evident from FIG. 4, one of the front walls 4a overhangs at a lower bag edge and the other front wall 4b overhangs at an upper bag edge. As a result of the staggering, it is possible to fold over the corresponding areas and fasten them, for example, with adhesive. And as is evident from FIG. 1, a further punching line 1 is formed on one of the front walls 4a. This further punching line 1 surrounds a removable section 5 in the subsequently produced packaging bag.

(11) The layered design of the plastic fabric composite is shown in FIG. 2. The plastic fabric composite includes a strip fabric 6, an outer film 7, an intermediate layer 8 between the strip fabric 6 and the outer film 7 and an adhesion-promoter layer 9.

(12) The strip fabric 6 and the outer film 7 form opposing surfaces of the plastic fabric composite, wherein, in the case of a packaging bag formed from the plastic fabric composite, the outer film 7 forms a bag outer side and the strip fabric 6 forms a bag inner side.

(13) The strip fabric 6 provides the greatest portion of the thickness of the plastic fabric composite. The strip fabric 6, which is formed from stretched film strips based on PP, typically has a thickness between 60 m and 140 m. In the exemplary embodiment, the thickness is approximately 90 m.

(14) The subsequent intermediate layer 8 is formed on the basis of polyolefine, wherein this can be, in particular, polyethylene, polypropylene, a mixture of polyethylene and polypropylene or also a polyolefine copolymer. The thickness is usually between 20 m and 55 m; in the exemplary embodiment, it is approximately 30 m.

(15) The intermediate layer 8 is incorporated, together with the adhesion-promoter layer 9, between the strip fabric 6 and the outer film 7, in an extrusion lamination, and so is reliable with good adhesion results. In particular, the initially molten material of the intermediate layer 8 adapts to the structure of the strip fabric 6 and, if necessary, can also penetrate the intermediate spaces to a certain extent. In the exemplary embodiment, the adhesion-promoter layer 9 has a thickness of approximately 5 m and consists of a polyethylene copolymer or polyethylene terpolymer.

(16) Provided as the outer film is a monofilm made of biaxially oriented polypropylene having a thickness between 10 m and 50 m, which is provided with an imprint 10 on its side adjoining the adhesion-promoter layer 9. As a result of this imprint 10, which is located on the inside and is applied in a reverse printing, a particularly high-quality appearance is achieved. The imprint 10 also is optimally protected by the outer film 4. In the exemplary embodiment shown, the thickness of the outer film is approximately 18 m.

(17) FIG. 3 shows the plastic fabric composite at the above-described punching lines 1, 1. According to the invention, the strip fabric 6 is completely severed along the punching lines 1, 1, wherein the punching lines 1, 1 end in the intermediate layer 8 and, therefore, the outer film 7 is undamaged at the punching lines 1, 1.

(18) Multiple advantages are achieved as a result. Initially, the plastic fabric composite remains closed, which is advantageous, in particular, with respect to the generation of a tear-open aid by means of the punching line 1, 1. In addition, as a result of the uniform structure of the punching line 1, 1, a particularly uniform tearing-open is possible, because all that needs to be torn along the punching line 1, 1 is the outer film 7, a portion of the intermediate layer 8, and the optionally provided adhesion-promoter layer 9. The force required for tearing open can be set so specifically that a controlled tearing with a clean tearing edge is possible, and inadvertent tearing is prevented.

(19) Finally, FIG. 4 shows, by way of example, a blank of a packaging bag that has not yet been filled. As described above, the edges easily can be folded over and glued, due to the staggered extension of the punching lines 1, 1a. The gussets 2 also provide for a large fill volume of the packaging bag, wherein a block shape results that also provides for better stacking and standing-up, in contrast to a simple cushion shape without gussets.

(20) The punching line 1 disposed on one of the front walls 4a is utilized to provide a removal opening, wherein the removable section 5 is torn out of the associated front wall 4a. In order to facilitate such a tearing-out, a small film slip 11 is provided at one end of the section 5, wherein a first area 11a of the film slip 11 is glued on the section 5 using adhesive and a second area 11b of the film slip 11 is free of adhesive. The second area 11b of the film slip 11, therefore, can be easily grasped by a user.

(21) FIG. 5 shows an alternative embodiment of a punching line 1, which 15 borders a removable section 5. As in the previously described embodiment, one end of the removable section 5 is covered by a film slip 11 in order to enable an easy initiation of a tear. An almost semi-circular punching-through 12, which cuts through the entire plastic fabric composite and enables an easy opening, is provided, where the film slip 11 covers the removable section 5. The glued film slip 11 ensures a secure covering. The punching line 1, which is attached to the punching-through 12, ends within the intermediate layer 8. The depth of the punching in the intermediate layer 8 differs in an alternating manner along the course of the punching line 1. Similar to a perforation, the tear-out forces which are required for an opening, are modulated by the form of the punching line 11, wherein there is no complete intersection.

(22) According to FIG. 6, the depth of the punching line 11 in the intermediate layer 8 differs in an alternating manner between sections with a low punching depth and sections, which are almost 5 completely severed.

(23) 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.