FILM PACKAGING HAVING CAVITIES AND BEING ORIENTED IN THE DIRECTION OF MOVEMENT OF THE MACHINE

Abstract

A recyclable, cold-sealing packaging having at least a first film and a cold-sealing compound and a print. The film is formed from a largely unmixed polyolefin, is stretched monoaxially in the machine direction and has at least two layers. At least one layer has an inorganic filler to create cavities in the layer.

Claims

1. A recyclable, cold-sealing packaging (11, 13), comprising: a first film (1), a cold-sealing compound (2), and a print (4), the first film (1) being formed from a substantially unmixed polyolefin, being stretched monoaxially in a machine direction and having at least two layers (5, 6), and at least one of the layers (6) comprising an inorganic filler for creating cavities in the layer.

2. The packaging according to claim 1, wherein the cold sealing compound (2) is arranged directly on the first film (1).

3. The packaging according to claim 1, wherein the cold sealing compound (2) is arranged evenly on the first film (1).

4. The packaging according to claim 1, wherein the at least one layer (6) with the inorganic filler is formed as an inner layer, the inner layer being surrounded by two unfilled ones of the layers (5).

5. The packaging according to claim 1, wherein a density of the first film (1) is less than 0.99 g/cm.sup.3 and is more than 0.60 g/cm.sup.3.

6. The packaging according to claim 1, wherein the polyolefin is a polyethylene.

7. The packaging according to claim 1, wherein the filler is a CaCO.sub.3, and the filler has a particle size of less than 6.5 m.

8. The packaging according to claim 1, wherein a proportion of the filler in the layer (6) is more than 5% by weight, and less than 60% by weight.

9. The packaging according to claim 1, wherein the first film (1) has a thickness of less than 40 m and more than 5 m.

10. The packaging according to claim 1, wherein the first film (1) has a gas permeability of less than 500 cm.sup.3/m.sup.2 d bar according to DIN EN ISO 2556.

11. The packaging according to claim 1, wherein the first film (1) has an opacity according to DIN 53416 of more than 80%.

12. The packaging according to claim 1, wherein the first film (1) has a tensile stiffness at 2% secant modulus according to DIN EN ISO 527-3 of more than 500 MPa.

13. The packaging according to claim 1, wherein the first film (1) has a tensile strength in the machine direction according to DIN EN ISO 527-3 of more than 90 MPa.

14. The packaging according to claim 1, wherein the first film (1) has a shrinkage according to DIN 55543-4 of less than 4%.

15. The packaging according to claim 1, wherein the first film (1) further comprises a layer (12) of ethylene-vinyl alcohol copolymer layer (EVOH) or polyamide (PA).

16. The packaging according to claim 1, further comprising at least one further film (3), the at least one further film (3) having at least two layers of polyethylene of different density and being stretched in the machine direction.

17. The packaging according to claim 1, wherein the first film (1) has a dart drop according to DIN EN ISO 7765-1 of more than 95 g.

18. A method for manufacturing a package (11, 13) comprising the following steps: producing different compositions, extruding a film (1) having at least two layers (5, 6), printing on the film (1), stretching the film (1) monoaxially in a machine direction.

19. The method according to claim 18, wherein the extruding is carried out as a blow extrusion.

20. The method according to claim 18, wherein the film (1) is stretched by more than a factor of 3.

21. The method according to claim 18, wherein the film (1) is joined to at least one further film (3) to form a package (11).

22. The method according to claim 18, further comprising applying a cold sealing compound (2) to the film (1).

23. The method of claim 20, further comprising the film being a recyclable, unmixed cold sealing packaging (13).

24. The method of claim 20, further comprising laminating a further film (3) to the film, and using the film as recyclable, unmixed packaging (11).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Further advantages and features of the invention are apparent from the description of an embodiment example with reference to drawings and from the drawings themselves.

[0102] Shown are

[0103] FIG. 1 a schematic representation of the film according to the invention with a cold sealing compound,

[0104] FIG. 2 a schematic representation of the film with additional layer,

[0105] FIG. 3 a schematic representation of the packaging according to the invention with a cold sealing compound,

[0106] FIG. 4 a further variant of the packaging according to the invention.

DETAILED DESCRIPTION

[0107] FIG. 1 shows a schematic representation of the packaging 13 according to the invention in the embodiment of the film 1 with a cold sealing compound 2 and the print 4. In the embodiment shown, the film 1 has a nine-layer structure.

[0108] Layer 6 is the filled layer, whereby the proportion of CaCO.sub.3 is approx. 55% by weight. Furthermore, layer 6 has a proportion of LDPE of approx. 15% by weight, a proportion of MDPE of approx. 18% by weight and a proportion of HDPE of approx. 12% by weight.

[0109] The layers 5 form the outer layers of the film 1, whereby the layers 5 have no fillers. In layer 5, the proportion of MDPE is approx. 70% by weight and the proportion of HDPE is 30% by weight. The HDPE is made, for example, from a Hostalen ACP 7740 F3, whose density is 0.946 g/cm.sup.3 and whose melt flow rate (at 190 C. at 5 kg) is 1.6 g/10 min according to ISO 1133.

[0110] Three further thin layers 10 are arranged between the filled layer 6 and the unfilled layers 5. Layer 10 is formed entirely from an MDPE, for example a Borealis Borshape FX1002, whose density is 0.937 g/cm.sup.3 and whose melt flow rate (at 190 C. at 5 kg) is 2 g/10 min in accordance with ISO 1133.

First Example

[0111] After blow extrusion, the film 1 has a thickness of 119 m. After monoaxial stretching by a factor of 4.82, the thickness of film 1 is 24.7 m, with a density of 0.92 g/cm.sup.3.

Second Example

[0112] After blow extrusion, the film 1 has a thickness of 147 m. After monoaxial stretching by a factor of 5.74, the thickness of film 1 is 40 m, with a density of 0.86 g/cm.sup.3.

[0113] The film 1 has a tensile stiffness of more than 632 MPa at 2% secant modulus and a tensile strength in the machine direction according to DIN EN ISO 527-3 of more than 119.3 MPa. Furthermore, the shrinkage of film 1 according to DIN 55543-4 is less than 2.1%, while the opacity according to DIN EN ISO 2813 is more than 95%. Film 1 has a dart drop of 135.4 g according to DIN EN ISO 7765-1.

[0114] FIG. 2 shows a schematic representation of the packaging 13 according to the invention in the form of film 1 with an additional layer 12. The film 1 essentially corresponds to the embodiments in FIG. 1, whereby in this embodiment an additional layer 12 of EVOH is arranged between the print 4 and the layer 5.

[0115] FIG. 3 shows a schematic representation of the packaging 11 according to the invention with a cold sealing compound 2. The packaging 11 is formed from the film 1 and the further film 3.

[0116] A print 4 is positioned between the other film 3 and the film 1, which is printed onto the opaque film 1 before it is joined. The print 4 is used to identify the food to be packaged and to visually recognize and support the brand image of the food brand.

[0117] In this embodiment, the other film 3 is formed with nine layers in a symmetrical structure. The five innermost layers 7 and 9 consist entirely of an MDPE, for example a Borealis Borshape FX1002, whereby the three innermost layers 9 are significantly thinner than the two surrounding layers 7.

[0118] In addition to the MDPE, the two outer layers 8 of the other film 3 each have a proportion of HDPE. In the embodiment shown, the proportion of HDPE is 85% by weight and is made, for example, from a Hostalen ACP 7740 F3.

First Example

[0119] The nine-layer, additional film 3 has a thickness of 139 m after blow extrusion. After monoaxial stretching by a factor of 5.95, the thickness of the additional film 3 is 25 m, with a density of 0.905 g/cm.sup.3.

Second Example

[0120] After blow extrusion, the film 1 has a thickness of 147 m. After monoaxial stretching by a factor of 5.74, the thickness of film 1 is 40 m, with a density of 0.86 g/cm.sup.3.

[0121] In the embodiment shown in FIG. 3, the film 1 has a three-layer structure. Layer 6 is the filled layer, whereby the proportion of CaCO.sub.3 is approx. 55% by weight. Furthermore, layer 6 has a proportion of LDPE of approx. 15% by weight, a proportion of MDPE of approx. 18% by weight and a proportion of HDPE of approx. 12% by weight.

[0122] The filled layer 6 is each surrounded by a layer 5, whereby the unfilled layer 5 has no fillers. In layer 5, the proportion of MDPE is approx. 70% by weight and the proportion of HDPE is 30% by weight.

[0123] After blow extrusion, the film 1 has a thickness of 140 m. After monoaxial stretching by a factor of 4.82, the thickness of film 1 is 29 m, with a density of 0.87 g/cm.sup.3.

[0124] The embodiment of the packaging 11 shown in FIG. 4 essentially corresponds to the embodiment in FIG. 3. Only the film 1 has a nine-layer structure as already described in detail in FIG. 1.