Tear tape for packaging and method of manufacturing tear tape

Abstract

The invention relates to a tear tape (10) for a package (28) comprising a layer system (12). The layer system (12) comprises a paper substrate (14) and an adhesive layer (16) arranged on a first side of the paper substrate (14). The adhesive layer (16) comprises in at least a partial area an uneven surface structure with opposing elevations (20) and opposing depressions (22). The invention further relates to a method of manufacturing a tear tape (10).

Description

Technical Field

[0001] The present invention relates to a tear strip for packaging, a method for manufacturing the tear strip, and a package having the tear strip. Background Technology

[0002] Tear tape for packaging is known in the prior art, facilitating the opening of sealed packaging. However, tear tape is currently primarily made of plastic, which presents problems in terms of environmental protection and recycling. Therefore, efforts have begun to explore the manufacture of compostable or biodegradable paper-based tear tape.

[0003] However, the disadvantage of these paper-based tear strips is that their tearing performance is far inferior to that of plastic tear strips. This is because paper-based tear strips often break during the tearing process, resulting in packaging that cannot be opened or can only be partially opened.

[0004] Therefore, an object of the present invention is to provide a paper-based tear strip with improved tear performance. A further object is to provide a method for manufacturing this tear strip. Finally, a further object is to provide packaging having this tear strip. Summary of the Invention

[0005] According to the present invention, the above-mentioned object is achieved by a tear strip having the features of claim 1, a method for manufacturing such a tear strip having the features of claim 9, and packaging according to claim 15. The dependent claims describe advantageous constructions that are easy to develop, wherein advantageous constructions of each aspect of the innovation should also be considered advantageous constructions of corresponding other aspects of the innovation.

[0006] A first aspect of the invention relates to a tear strip for packaging, comprising a layer system. The layer system includes a paper substrate and an adhesive layer disposed on a first side of the paper substrate. According to the invention, tear performance is improved by including an uneven surface structure with relatively raised and relatively recessed areas in at least a portion of the adhesive layer. In other words, the invention provides a paper-based tear strip whose adhesive layer comprises an uneven surface structure with relatively raised (peaks) and relatively recessed (valleys, depressions) in a portion or all of its area. While not wishing to be bound by this theory, the inventors assume that such an uneven surface structure improves tear performance. Because depressions or valleys weaken local adhesion, while raised or peaked areas make the bond stronger and thus more firmly bonded, the tear strip can adhere to the relevant packaging with varying degrees of localized strength. When tearing the packaging, the localized weakening of adhesion prevents the paper-based tear strip from being torn due to excessive adhesion to the packaging. However, the raised areas reliably prevent the overall adhesion of the tear strip to the relevant packaging from being too weak. Preferably, the adhesive layer comprises 20 to 100 raised areas per square centimeter of the paper substrate. Particularly preferably, the layer comprises 40 to 60 protrusions per square centimeter, and more particularly preferably about 50 protrusions per square centimeter. Essentially, the adhesive layer can consist of one or more suitable adhesives and optionally include additives. For example, adhesives based on poly(meth)acrylate, natural or synthetic rubber, and / or sealant wax can be used. Generally, “a” should be understood as an indefinite article within the scope of this invention, and thus should generally be understood as “at least one” unless explicitly indicated to the contrary. Of course, “a” can also be understood as “only one”.

[0007] In an advantageous configuration of the invention, the paper substrate is compostable and / or biodegradable, thereby improving environmental balance. Alternatively or additionally, the basis weight of the paper substrate is 80 g / m³. 2 With 200g / m 2 Between, especially at 100g / m 2 With 140g / m 2 Between, specifically approximately 120g / m 2This ensures the stability of the paper substrate, thereby ensuring favorable sealing and tearing performance of the tear strip in most applications and embodiments. Particularly preferably, the amount of adhesive applied per unit area of ​​the paper substrate depends on or is a function of the paper substrate's basis weight, wherein a higher basis weight results in a higher amount of adhesive applied per unit area. This ensures reliable sealing of the packaging while preventing premature tearing or removal of the tear strip, thus ensuring reliable tearing performance. Alternatively or additionally, the paper substrate has a stability of at least 75 N / 15 mm, preferably at least 110 N / 15 mm, in the main extension direction; and / or, the thickness of the paper substrate is between 100 μm and 250 μm, particularly between 150 μm and 200 μm, thereby ensuring favorable sealing and tearing performance of the tear strip. The main extension direction can be understood as the direction in which the tear strip extends the longest, i.e., along which the relevant packaging is torn.

[0008] A further advantage is that the first and / or second sides of the paper substrate are embossed and / or bleached and / or dyed and / or printed. This allows the tear strip to be adapted particularly easily to different optical and / or functional requirements. For example, the embossed paper substrate can have better non-stick properties on its non-adhesive second side.

[0009] In a further advantageous embodiment of the invention, the adhesive layer is applied entirely or in sections to the first side. In other words, the entire surface of the paper substrate is coated with the adhesive layer, or only one or more surface areas are coated with the adhesive layer. This allows for control over both adhesion and tear resistance. Alternatively or additionally, the coating weight of the adhesive layer is approximately 15 g / m². 2 and 60g / m 2 Between, especially at 20g / m 2 and 30g / m 2 Between these elements, favorable tear-off properties are achieved. In a further construction, the adhesive layer has a regular surface structure, particularly a dotted structure and / or a wave-like structure and / or a linear structure and / or a pyramidal structure and / or a truncated pyramidal structure and / or a hexagonal structure and / or a linear structure with recesses and / or a dome structure, to achieve particularly uniform tear-off properties. The ridges and depressions of the surface structure comprise regularly arranged structural units, wherein only one type of structural unit may be provided, or two or more types of structural unit may be provided. When multiple types of structural unit are provided, the volumes of these structural units may be the same or different.

[0010] An additional improvement in tear resistance is that at least a portion of the surface structure of the adhesive layer includes periodic structural units, wherein at least one periodic extension vector of the structural unit is preferably inclined relative to the main extension direction of the paper substrate. In other words, the periodic extension vector of the structural unit is not parallel or coaxial with the main extension direction of the paper substrate, but rather forms an angle with the main extension direction of the paper substrate that is neither equal to 0 degrees nor 180 degrees. When the tear strip is pulled apart, the forces generated internally are advantageously deflected and better distributed, thereby reliably preventing the tear strip from being torn.

[0011] In a further advantageous embodiment of the invention, a separating layer is provided entirely or in sections on the second side of the paper substrate. The coating weight of the separating layer is preferably 0.1 g / m². 2 and 2.0g / m 2 Between, especially at 0.2g / m 2 and 1.0g / m 2 Between. This reliably prevents tearing of the tape, such as during winding, from creating obstructions or adhering to itself. The separator layer can be formed based on silicone, or other separator layers based on polyacrylates, urethanes, polyvinyl ether waxes, or other suitable compounds and mixtures thereof can be provided.

[0012] Alternatively or additionally, it has proven advantageous to provide a separating strip on the side of the adhesive layer facing away from the paper substrate, which also prevents the tear strip from getting stuck or adhering to undesirable areas of itself or related packaging. For example, the separating strip can be a separating foil or separating paper, such as silicone paper.

[0013] In a further configuration, the tear strip is wound onto a spool, preferably laterally wound, and / or packaged as a flat roll to facilitate storage or transport of the tear strip.

[0014] A second aspect of the invention relates to a method of manufacturing a tear strip for packaging, in which an adhesive layer is manufactured onto a first side of a paper substrate. According to the invention, the adhesive layer is manufactured such that at least a portion of its area includes an uneven surface structure having relatively raised and relatively recessed areas, thereby improving tear performance. The beneficial effects of the second aspect are described with reference to the first aspect, and the advantageous construction of the first aspect should be considered as an advantageous construction of the second aspect. The advantageous construction of the second aspect should also be considered as an advantageous construction of the first aspect. After manufacturing the tear strip, it can be wound laterally onto a roll, allowing for a usable length of up to 40,000 meters or longer, typically 10,000 to 20,000 meters. Alternatively, the tear strip can also be packaged as a flat roll.

[0015] In a further advantageous embodiment of the invention, the paper substrate is provided with an uneven surface structure before the adhesive layer is applied, and / or an uneven surface structure is generated in the adhesive layer. Thus, the uneven surface structure of the adhesive layer can generally be achieved by applying the adhesive layer itself accordingly unevenly to a paper substrate that has a uniform surface in at least some areas. However, alternatively or additionally, an uneven surface is first provided in at least some areas of the paper substrate, and then the adhesive layer is applied uniformly or unevenly to the paper substrate. The first and / or second sides of the paper substrate can generally have uneven surfaces. Smooth paper substrates are generally easier to coat than rough or structured paper substrates.

[0016] In a further advantageous embodiment of the invention, an anilox roller, particularly a hachure roller, is used to apply an adhesive layer to a paper substrate, thereby applying a specified local dosage of adhesive to the paper substrate to form an adhesive layer, thus producing a surface structure with predetermined ridges and depressions. In addition to the geometry of one or more structural elements forming the surface structure, the local coating volume of the adhesive layer can be precisely controlled by appropriately selecting the recesses and ridges of the anilox roller.

[0017] A further advantage is that a printed layer and / or a separating layer are provided on the second side of the paper substrate. The printed layer allows for the adaptation of the optical imprint of the tear strip. Furthermore, the tear strip can also include symbols or usage instructions. Printing can typically be done using gravure printing, flexographic printing, offset printing, laser printing, inkjet printing, or any other suitable printing method. Printing inks can be based on nitrocellulose (NC), polyurethane (PU), polyvinyl chloride (PVC), polyvinyl butyral (PVB), or other adhesives. The separating layer prevents accidental adhesion of the tear strip, such as adhesion to itself.

[0018] Further proving advantageous is the application of a lacquer layer between the printed layer and the separator layer, which provides a simple way to protect the printed layer from damage and also further improves the optical performance.

[0019] The tear strip can be cut into multiple strips, preferably using scissors, so that the width of the tear strip is suitable for different application requirements. When manufacturing the tear strip, multiples of this width can be used initially to facilitate one or more coating processes of the forming layer system. Preferably, the width of the cut tear strip is between 2 mm and 15 mm, particularly between 4 mm and 8 mm.

[0020] A third aspect of the invention relates to a package comprising at least one tear strip, wherein the tear strip is a tear strip according to the first aspect of the invention and / or a tear strip manufactured using a method according to the second aspect of the invention. The beneficial effects of the third aspect of the invention can be referenced to the descriptions of the first and second aspects of the invention, wherein advantageous constructions of the first and second aspects of the invention should be considered advantageous constructions of the third aspect of the invention. Conversely, advantageous constructions of the third aspect of the invention should also be considered advantageous constructions of the first and second aspects of the invention. Preferably, the package is fully compostable or biodegradable. Furthermore, the package may comprise two or more tear strips. Attached Figure Description

[0021] Further features of the invention will be apparent from the claims, drawings, and description of the drawings. Features and combinations of features recited in the specification, as well as features and combinations of features recited in the description of the drawings and / or shown only in the drawings, can be applied not only in their respective specified combinations, but also in other combinations without departing from the scope of the invention. Therefore, embodiments that can be derived from the feature combinations of the described embodiments, though not explicitly shown and illustrated in the drawings, should also be considered as covered and disclosed by the invention. Embodiments and combinations of features that do not include all features of the original independent claims should also be considered as disclosed. Furthermore, embodiments and combinations of features that exceed or deviate from the relationships of the claims, particularly those recited in this specification, should also be considered as disclosed by the invention. In these drawings:

[0022] Figure 1 This is a schematic cross-sectional view of the tear strip according to the present invention;

[0023] Figure 2 This is a partial top view of the tear strip according to the present invention during the coating process of the adhesive layer;

[0024] Figure 3 It is a 3D diagram showing the tearing open of the roll;

[0025] Figure 4 It is a top view of the packaging with tear strips; and

[0026] Figure 5 yes Figure 4 A magnified view of point V in the middle.

[0027] Figure label:

[0028] 10. Tear open the tape

[0029] 12-layer system

[0030] 14 Paper substrate

[0031] 16 Adhesive layer

[0032] 18 Separator Layers

[0033] 20 bulges

[0034] 22. Depression

[0035] 24 cores

[0036] 26. Tear open the roll.

[0037] 28 Packaging

[0038] H Main extension direction

[0039] V extended vector Detailed Implementation

[0040] Figure 1 A schematic cross-sectional view of the tear strip according to the present invention is shown. The tear strip 10 includes a layer system 12, wherein, in this embodiment, the layer system 12 includes a paper substrate 14, an adhesive layer 16 disposed on a first side of the paper substrate 14, and a separator layer 18 disposed substantially optionally on a second side of the paper substrate 14. As can be seen from the cross-section, the adhesive layer 16 includes an uneven surface structure with a wavy structure having relatively raised areas 20 and relatively recessed areas 22.

[0041] The tear strip 10 shown in the attached diagram is compostable and / or biodegradable. Generally, the paper substrate 14 is based on cellulose. However, other paper types, such as PET fiber-based paper, can also be used. The basis weight of the paper substrate 14 is 90 g / m². 2 and 200g / m 2 Between, for example, 120g / m 2 The paper substrate 14 may be white, bleached, unbleached, or dyed. Similarly, printing may be performed on one or both sides of the paper substrate 14. The paper substrate 14 is in the main extension direction H (see...). Figure 2 It must have a mechanical stability of at least 75 N / 15 mm in the direction of operation, particularly at least 110 N / 15 mm or higher. Figure 1 As shown, the paper substrate 14 is smooth, thus possessing good coating ability. However, the first and / or second sides of the paper substrate 14 may also include structured surfaces on which the adhesive layer 16 and / or the release layer 18 are coated. By embossing the paper substrate 14, better non-stick properties can be achieved on its non-adhesive second side.

[0042] In this embodiment, the adhesive layer 16 is applied to the entire first side of the paper substrate 14, or it may be applied only to a portion of the first side. (See reference) Figure 2 , Figure 2This is a partial top view schematic diagram of the tear strip according to the invention during the coating process of the adhesive layer. The structured surface of the adhesive layer 16 includes a regular linear or wavy structure, which is composed of multiple lines or waves formed by ridges 20 as structural units. The wavy or linear structure shown in the figure can be produced, for example, by a corresponding gravure of a coating roller, such as by a hachure roller. Furthermore, as... Figure 2 As shown, multiple lines repeat periodically on the surface of the paper substrate 14, thus the linear structure with ridges 20 and depressions 22 is regularly formed. Furthermore, the periodic extension vector V of the linear structural units is set obliquely relative to the main extension direction H of the paper substrate 14. In other words, the lines or ridges 20 do not extend perpendicularly or parallel to the main extension direction H, but rather diagonally. However, other regular or irregular surface structures (patterns) can also be generated to replace the linear or wavy surface structures.

[0043] The adhesive layer 16 can use an adhesive based on polyacrylate, natural or synthetic rubber, or sealant wax. The application rate of the adhesive is typically 15 g / m². 2 Up to 60g / m 2 Between, especially at 20g / m 2 Up to 30g / m 2 between.

[0044] The separator layer 18 can be coated on the entire surface or only a portion of the surface of the paper substrate 14. The separator layer 18 is typically silicone-based, but other separators, such as those based on polyacrylates, urethanes, or polyvinyl ether waxes, can also be used. The coating weight of the separator layer 18 is typically 0.1 g / m². 2 and 2.0g / m 2 Between, especially at 0.2g / m 2 and 1.0g / m 2 between.

[0045] Alternatively, the separator layer 18 can be omitted, and a separator foil (not shown in the figure) or separator paper, such as silicone paper, can be covered on the adhesive layer 16.

[0046] Optionally, printing can be performed on the paper substrate 14, particularly on its non-adhesive side. When a separator layer 18 is provided, printing is preferably performed directly on the paper substrate 14 before applying the separator layer 18. Printing can be performed using gravure printing, flexographic printing, offset printing, or other printing methods. The printing ink can be based on NC, PU, ​​PVC, PVB, or other adhesives. Optionally, an additional varnish layer (not shown) can be applied between the printed layer and the separator layer 18. In this embodiment, the layer structure of the layer system 12 is: adhesive layer 16—paper substrate 14—printed layer—varnish layer—separator layer 18.

[0047] Figure 3 A perspective view of the tear tape roll 26 is shown. The tear tape 10 is wound around the core 24. The tear tape 10 is preferably wound laterally, allowing for a usable length of up to 40,000 meters, typically 10,000 to 20,000 meters. Alternatively, the tear tape 10 can also be packaged as a flat roll. The tear tape 10 can be cut into narrow strips. The width for the most commonly used packaging 28 is typically about 2 mm to 15 mm, particularly 4 mm to 8 mm. Cutting is usually done using scissors, but other cutting or splitting methods are also possible.

[0048] Figure 4 A top view of the package 28 in its unfolded state is shown, wherein the package 28 is provided with a tear strip 10 according to another embodiment of the present invention. (Combined) Figure 5 Let's understand together, among which, Figure 5 yes Figure 4 A magnified view of the middle V section. Specifically, from... Figure 5 As can be seen, in this scheme, the adhesive layer 16 has a regular dot pattern of dot-like protrusions 20 and corresponding depressions 22.

[0049] Parameter values ​​specified in documents defining the processes and measurement conditions used to characterize the subject matter of this invention should be considered to be included within the scope of this invention and within the range of deviations from this invention (e.g., caused by measurement errors, systematic errors, weighing errors, DIN tolerances, etc.).

Claims

1. A tear strip (10) for packaging (28), comprising a layer system (12), said layer system (12) comprising a paper substrate (14) and an adhesive layer (16) disposed on a first side of said paper substrate (14), characterized in that, The adhesive layer (16) includes at least a portion of an uneven surface structure with relatively raised (20) and relatively recessed (22) areas. The surface structure of the adhesive layer (16) includes periodic structural units in at least a portion of the area, wherein at least one periodic extension vector (V) of the structural unit is inclined relative to the main extension direction (H) of the paper substrate (14).

2. The tear strip (10) according to claim 1, characterized in that, The paper substrate (14) is compostable and / or biodegradable; and / or, the basis weight of the paper substrate (14) is 80 g / m³. 2 and 200 g / m 2 Between; and / or, the paper substrate (14) has a stability of at least 75 N / 15 mm in the main extension direction (H); and / or, the thickness of the paper substrate (14) is between 100 µm and 250 µm.

3. The tear strip (10) according to claim 1 or 2, characterized in that, The first and / or second sides of the paper substrate (14) are embossed and / or bleached and / or dyed and / or printed.

4. The tear strip (10) according to claim 1, characterized in that, The adhesive layer (16) is applied entirely or in sections on the first side; and / or, the coating weight of the adhesive layer (16) is 15 g / m². 2 and 60 g / m 2 Between; and / or, the adhesive layer (16) includes a regular surface structure.

5. The tear strip (10) according to claim 1, characterized in that, A separating layer (18) is provided entirely or in sections on the second side of the paper substrate (14), wherein the coating weight of the separating layer (18) is 0.1 g / m². 2 Up to 2.0 g / m 2 between.

6. The tear strip (10) according to claim 1, characterized in that, The adhesive layer (16) has a separation strip on the side opposite to the paper substrate (14).

7. The tear strip (10) according to claim 1, characterized in that, The tear strip (10) is wound on a roll (26) laterally, and / or the tear strip (10) is packaged into a flat roll.

8. The tear strip (10) according to claim 1, characterized in that, The paper substrate (14) is compostable and / or biodegradable; and / or, the basis weight of the paper substrate (14) is 100 g / m³. 2 and 140 g / m 2 Between; and / or, the paper substrate (14) has a stability of at least 110 N / 15 mm in the main extension direction (H); and / or, the thickness of the paper substrate (14) is between 150 µm and 200 µm.

9. The tear strip (10) according to claim 1, characterized in that, The adhesive layer (16) is applied entirely or in sections on the first side; and / or, the coating weight of the adhesive layer (16) is 20 g / m². 2 and 30 g / m 2 Between; and / or, the adhesive layer (16) includes a dotted structure and / or a wave-like structure and / or a linear structure and / or a pyramidal structure and / or a truncated pyramidal structure and / or a hexagonal structure and / or a linear structure with a recess and / or a dome structure.

10. The tear strip (10) according to claim 1, characterized in that, A separating layer (18) is provided entirely or in sections on the second side of the paper substrate (14), wherein the coating weight of the separating layer (18) is 0.2 g / m². 2 Up to 1.0 g / m 2 between.

11. A method of manufacturing a tear strip (10) for packaging (28), comprising a manufacturing layer system (12) wherein an adhesive layer (16) is coated on a first side of a paper substrate (14), characterized in that, The adhesive layer (16) is manufactured with an uneven surface structure having relatively raised (20) and relatively recessed (22) areas in at least a portion of the region. The surface structure of the adhesive layer (16) includes periodic structural units in at least a portion of the area, wherein at least one periodic extension vector (V) of the structural unit is inclined relative to the main extension direction (H) of the paper substrate (14).

12. The method according to claim 11, characterized in that, Before the adhesive layer (16) is applied, the paper substrate (14) is provided with the uneven surface structure; and / or, the uneven surface structure is generated in the adhesive layer (16).

13. The method according to claim 11 or 12, characterized in that, The adhesive layer (16) is applied to the paper substrate (14) by means of an anilox roller, which is a triple helical roller.

14. The method according to claim 11, characterized in that, A printing layer and / or a separating layer (18) are provided on the second side of the paper substrate (14).

15. The method according to claim 14, characterized in that, A paint layer is applied between the printed layer and the separating layer (18).

16. The method according to claim 11, characterized in that, The tear strip (10) is cut into multiple strips by scissors, wherein the width of the multiple strips is between 2 mm and 15 mm.

17. The method according to claim 11, characterized in that, The tear strip (10) is cut into multiple strips by scissors, wherein the width of the multiple strips is between 4 mm and 8 mm.

18. A package (28) comprising at least one tear strip (10), said at least one tear strip (10) being formed according to any one of claims 1 to 10, and / or manufactured using the method according to any one of claims 11 to 17.

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