TEAR-OPEN STRIP FOR A PACKAGING AND METHOD FOR PRODUCING A TEAR-OPEN STRIP

Abstract

The invention relates to a tear-open strip (10) for a packaging (28), comprising a layer system (12) which has a paper substrate (14) and an adhesive layer (16) arranged on a first side of the paper substrate (14), the adhesive layer (16) having at least in some regions an uneven surface structure with relative elevations (20) and relative depressions (22). The invention also relates to a method for producing such a tear-open strip (10).

Claims

1. A tear-open strip for a packaging, comprising a layer system, which comprises a paper substrate and an adhesive layer arranged on a first side of the paper substrate, wherein the adhesive layer comprises an uneven surface structure with relative elevations and relative depressions at least in some regions.

2. The tear-open strip according to claim 1, wherein the paper substrate is compostable and/or biodegradable and/or that the paper substrate has a grammage between 80 g/m.sup.2 and 200 g/m.sup.2, in particular between 100 g/m.sup.2 and 140 g/m.sup.2, and/or that the paper substrate has a stability of at least 75 N/15 mm, preferably of at least 110 N/15 mm in a main extension direction and/or a thickness between 100 m and 250 m, in particular between 150 m and 200 m.

3. The tear-open strip according to claim 1, wherein the first and/or a second side of the paper substrate is embossed and/or bleached and/or dyed and/or printed.

4. The tear-open strip according to claim 1, wherein the adhesive layer is applied to the first side all over or in sections and/or that the adhesive layer has an application weight between 15 g/m.sup.2 and 60 g/m.sup.2, in particular between 20 g/m.sup.2 and 30 g/m.sup.2 and/or that the adhesive layer comprises a regular surface structure, in particular a dot structure and/or a wave structure and/or a line structure and/or a pyramid structure and/or a truncated pyramid structure and/or a hexagonal structure and/or a line structure with wells and/or a calotte structure.

5. The tear-open strip according to claim 4, wherein the surface structure of the adhesive layer comprises a periodic structural element at least in some regions, wherein at least one extension vector of the periodicity of the structural element is preferably arranged obliquely to the main extension direction of the paper substrate.

6. The tear-open strip according to claim 1, wherein a separating layer is arranged all over or in sections on the second side of the paper substrate, wherein an application weight of the separating layer is preferably between 0.1 g/m.sup.2 and 2.0 g/m.sup.2, in particular between 0.2 g/m.sup.2 and 1.0 g/m.sup.2.

7. The tear-open strip according to claim 1, wherein a separating strip is arranged on a side of the adhesive layer facing away from the paper substrate.

8. The tear-open strip according to claim 1, wherein it is rolled up on a reel with preferably traversing winding and/or is packaged as a flat reel.

9. A method for producing a tear-open strip for a packaging, in which a layer system is produced in that an adhesive layer is applied to a first side of a paper substrate, wherein the adhesive layer is produced with an uneven surface structure with relative elevations and relative depressions at least in some regions.

10. The method according to claim 9, wherein the paper substrate is provided with an uneven surface structure before applying the adhesive layer and/or that the uneven surface structure is generated in the adhesive layer.

11. The method according to claim 9, wherein the adhesive layer is applied to the paper substrate by means of an anilox roll, in particular a hachure roll.

12. The method according to claim 9, wherein the paper substrate is provided with a printing layer and/or with a separating layer on the second side.

13. The method according to claim 12, wherein a varnish layer is applied between the printing layer and the separating layer.

14. The method according to claim 9, wherein the tear-open strip is cut into multiple strips, preferably by means of scissors cut, wherein the strips preferably have a width between 2 mm and 15 mm, in particular between 4 mm and 8 mm.

15. A packaging comprising at least one tear-open strip according to claim 1.

16. A packaging comprising at least one tear-open strip, which is produced by a method according to claim 9.

Description

[0021] Further features of the invention are apparent from the claims, the figures and the description of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not comprise all of the features of an originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or deviate from the feature combinations set out in the relations of the claims. There shows:

[0022] FIG. 1 a schematic cross-section through a tear-open strip according to the invention;

[0023] FIG. 2 a schematic and partial top view to the tear-open strip according to the invention during the application of an adhesive layer;

[0024] FIG. 3 a schematic perspective view of a tear-open strip reel;

[0025] FIG. 4 a top view of a packaging, on which the tear-open strip is arranged; and

[0026] FIG. 5 an enlarged representation of the detail V shown in FIG. 4.

[0027] FIG. 1 shows a schematic cross-section through a tear-open strip 10 according to the invention. The tear-open strip 10 includes a layer system 12, which, in the present case, comprises a paper substrate 14, an adhesive layer 16 arranged on a first side of the paper substrate 14 as well as a basically optional separating layer 18 arranged on the second side of the paper substrate 14. One recognizes in the cross-section that the adhesive layer 16 comprises an uneven surface structure with a wave-like structure of relative elevations 20 and relative depressions 22.

[0028] The shown tear-open strip 10 is compostable and/or biodegradable. Generally, the paper substrate 14 is formed based on cellulose. However, other paper types, for example paper based on PET fibers, can also be provided. The grammage of the paper substrates 14 is between 90 and 200 g/m.sup.2, for example 120 g/m.sup.2. The paper substrate 14 can be white or bleached or unbleached or dyed. Similarly, it can be provided that the paper substrate 14 is printed on one side or on both sides. The paper substrate 14 has a high mechanical stability in the main extension direction H (see FIG. 2) or running direction of at least 75 N/15 mm, in particular of at least 110 N/15 mm or more. As one sees in FIG. 1, the paper substrate 14 is smooth to allow a good capability of coating. However, it can basically also be provided that the paper substrate 14 comprises a structured surface on its first and/or second side, to which the adhesive layer 16 and/or the separating layer 18 are applied. By embossing the paper substrate 14, a better nonstick characteristic of the non-adhering, second side can often be achieved.

[0029] In the present case, the adhesive layer 16 is applied to the first side of the paper substrate 14 all over, wherein only an application in some regions can basically also be provided. As one recognizes in FIG. 2, which shows a schematic and partial top view to the tear-open strip 10 according to the invention during the application of the adhesive layer 16, the structured surface of the adhesive layer 16 comprises a regular line or wave structure, which is formed by lines or waves formed by the elevations 20 as the structural elements. The shown wave or line structure can for example be generated by means of a corresponding gravure of a coating cylinder, for example by means of a hachure roll. Furthermore, one sees in FIG. 2 that the line structure with the elevations 20 and depressions 22 is regularly formed, since the lines periodically repeat themselves on the surface of the paper substrate 14. In addition, an extension vector V of the periodicity of the line structural element is arranged obliquely to the main extension direction H of the paper substrate 14. In other words, the lines or elevations 20 do not extend perpendicularly or parallel to the main extension direction H, but extend in diagonal manner. However, other regular or irregular surface structures (patterns) can basically also be generated instead of line- or wave-shaped surface structures.

[0030] For the adhesive layer 16, an adhesive based on polyacrylate, a natural or synthetic rubber or a sealing wax can be employed. The adhesive application is typically in the range between 15 and 60 g/m.sup.2, in particular at 20 to 30 g/m.sup.2.

[0031] The separating layer 18 can also be applied all over or only to certain surface regions of the paper substrate 14. The separating layer 18 is typically based on silicone, however, other separating agents, for example based on polyacrylate, carbamate or polyvinyl ether wax, can generally also be used. The application weight of the separating layer 18 is normally in the range between 0.1 and 2.0 g/m.sup.2, in particular between 0.2 and 1.0 g/m.sup.2.

[0032] Alternatively, the separating layer 18 can be omitted and the adhesive layer 16 can instead be covered with a separating foil (not shown) or a separating paper, for example a silicone paper.

[0033] Optionally, the paper substrate 14 can be printed, in particular on the non-adhering side. If a separating layer 18 is provided, the print is preferably directly effected on the paper substrate 14 before coating with the separating layer 18. The print can be effected in gravure printing, flexographic printing, offset printing or another printing method. The printing ink can be based on NC, PU, PVC, PVB or other binders. Optionally, an additional varnish coating (not shown) can be applied between the printing layer and the separating layer 18. In this case, the layer construction of the layer system 12 would be adhesive layer 16paper substrate 14printing layervarnish layerseparating layer 18.

[0034] FIG. 3 shows a schematic perspective view of a tear-open strip reel 26. Hereto, the tear-open strip 10 is wound to a core 24. Therein, the tear-open strip 10 is preferably reeled with traversing winding, whereby a large running length of up to 40,000 m, typically 10,000 to 20,000 m, is allowed. Alternatively, the tear-open strip 10 can also be packaged as a flat reel. The tear-open strip 10 can be cut into narrower strips. The typical strip width for the most usual packagings 28 is about 2 to 15 mm, in particular 4 to 8 mm. Cutting is typically effected in scissors cut, however, other cutting or separating types are also possible.

[0035] FIG. 4 shows a top view of an unfolded packaging 28, on which a further embodiment of the tear-open strip 10 according to the invention is arranged. FIG. 4 is explained in synopsis with FIG. 5, which shows an enlarged representation of the detail V. One recognizes in particular in FIG. 5 that the adhesive layer 16 has a regular dot pattern of dot-shaped elevations 20 and corresponding depressions 22 in the present case.

[0036] The parameter values specified in the documents for definition of process and measurement conditions for characterizing specific characteristics of the inventive subject matter are to be regarded as encompassed by the scope of the invention also within the scope of deviationsfor example due to measurement errors, system errors, weighing errors, DIN tolerances and the like.

LIST OF REFERENCE CHARACTERS

[0037] 10 Tear-open strip [0038] 12 layer system [0039] 14 paper substrate [0040] 16 adhesive layer [0041] 18 separating layer [0042] 20 elevations [0043] 22 depressions [0044] 24 core [0045] 26 tear-open strip reel [0046] 28 packaging [0047] H main extension direction [0048] V extension vector