Embossing structure for an embossing roller for glueing tissue products, a corresponding embossing roller, a corresponding tissue product and a method for producing an embossing roller

Abstract

Embossing structure for an embossing roller for gluing tissue products, which has at least one embossing elevation with an embossing surface for creating an embossing motif, characterized in that a plurality of gluing elevations are arranged on the embossing elevation, which are raised relative to the embossing elevation and provide a smaller pressing surface relative to the embossing surface.

Description

[0001] The invention relates to an embossing structure for an embossing roller for gluing tissue products, which has at least one embossed elevation with an embossed surface for creating an embossed motif. Furthermore, a corresponding embossing roller, a corresponding tissue product, and a method for producing an embossing roller having the embossing structure are described.

[0002] From EP 1319 748 B9 an embossed tissue paper and an embossing tool for its production are known, wherein the embossing tool has, for design purposes, a first group of large, widely spaced embossed elevations and a second group of smaller, more narrowly spaced embossed elevations compared to the first group, which are arranged on a pedestal so that the upper sides of the first and second embossed elevations lie on the same plane and provide a common pressing surface.

[0003] WO 2008 / 132612 A1 discloses an embossing roller for a paper substrate with an embossing surface comprising an embossing line element and a step extending longitudinally or transversely to the embossing line element, which is arranged next to one of two opposite edges at the upper end of the embossing line element. The disclosed device aims to produce particularly clear embossed edges in order to convey a qualitative impression to the customer.

[0004] EP 1209 289 B1 discloses a device for producing absorbent crepe paper. The device comprises an embossing roller with a convex cylindrical surface for creating micro-embossings. A plurality of relief-shaped pins are arranged on the cylindrical surface, each of the pins consisting of a truncated pyramid-shaped base with a rectangular base plate and a flattened apex or free end portion.

[0005] Tissue products such as toilet paper or kitchen rolls are often constructed from multiple layers of tissue. The at least one top layer and the at least one bottom layer are each embossed in the embossing nip between a positively engraved steel roller and a smooth, rubber-coated counter roller in such a way that the resulting raised embossed figures face each other.

[0006] In order to bond the layers together, glue is applied to the raised tissue structure of the tissue while it is still on an embossing roller using a gluing unit.

[0007] As the embossing roller continues to rotate, the required gluing pressure is generated either in the top-to-top process by the counterpressure of the second steel embossing roller or in the nested process by an additional rubber-coated pressure roller.

[0008] Furthermore, it is common practice for the entire pressing surface of the embossed design to be coated with glue. This leads to the hardening of the coated surfaces, a comparatively high glue consumption, and, with large pressing surface areas, inadequate adhesion of the layers cannot be achieved despite the large amount of glue transferred.

[0009] In these cases, the insufficient adhesion is due to the fact that, due to the high pressing surface proportion, the total pressure in the gluing position is not sufficient to achieve the specific pressure at the point to be glued.

[0010] The resulting constraint not to exceed a critical pressing area ratio prevents the development of aesthetically pleasing designs that would require a high pressing area ratio.

[0011] Practice has shown that problems with layer adhesion occur when the pressing surface is high. In addition, the continuous glue surfaces on the pressing surfaces create a relatively high resistance to deformation of the tissue product, which is perceived as hard and unpleasant.

[0012] Devices known from the state of the art for producing tissue products therefore have a technical limit as regards the pressing area share of designs, which severely restricts the range of possible designs for tissue paper.

[0013] It is therefore the object of the invention to provide an embossing structure for an embossing roller, by means of which a reduction in glue consumption and production costs, an increase in the softness of the final product and aesthetically pleasing designs with high pressing surface proportions are made possible.

[0014] The problem is solved with the features of the independent claims.

[0015] Accordingly, it is provided that a plurality of gluing elevations are arranged on the embossed elevation, which are raised relative to the embossed elevation and provide a smaller pressing surface relative to the embossed surface.

[0016] The embossed elevation can be designed in particular to create a visible, in particular large-scale embossed motif on the tissue product. For this purpose, the embossed elevation can have a constant first height. The embossed motif can, for example, be highlighted in color compared to the rest of the tissue. The gluing elevations can be applied to the upper side of the embossed elevation or created by removing material from the embossed structure. Starting from the height of the embossed elevations, the gluing elevations can be raised above the first height by a second height. The gluing elevations have the particular purpose or advantage of creating relatively small pressing surfaces within the relatively large embossed surface, by means of which pressing surfaces a secure layer adhesion between the at least two tissue layers is enabled. The pressing surface can essentially correspond to the base area of ​​the embossed elevation.

[0017] In contrast, the pressing surface can be the sum of the surfaces of all bonding protrusions on the embossed protrusion. The total height of the embossed structure results from the sum of the first height of the embossed protrusion and the second height of the bonding protrusions.

[0018] In particular, it can be provided that the pressing surface area provided by the bonding elevations is less than 20%, preferably less than 10%, particularly preferably less than or equal to 6% of the embossed surface. It can be provided that the distances between the bonding elevations are each between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm. The smaller the pressing surface area, the larger the desired embossed designs can be without the tissue product being perceived as too hard and without the ply adhesion falling into an insufficient range.

[0019] It can be provided that the gluing elevations are uniformly formed and regularly distributed over the embossed surface. The gluing elevations can, for example, be linear and parallel. The lines can be curved or jagged. Alternatively, the lines can intersect. Furthermore, alternatively, it can be provided that the gluing elevations are arranged at specific points on the embossed elevation. These specific gluing elevations can have different shapes and can, for example, be square, round, oval, in the form of a floral pattern or similar. It is particularly advantageous if the gluing elevations extend over the entire embossed surface of the embossed elevation and are, for example, evenly spaced from one another.

[0020] It can be provided that the bonding elevations are linear ribs, between which grooves are formed, wherein the pressing surface is segmented by the grooves. The segmentation of the pressing surface pursues the goal of breaking up the pressing surfaces by introducing parallel lines into, in particular, independent individual surfaces. The grooves can extend to the level of the first height of the embossed elevation. The side walls of the grooves can be defined by the ribs surrounding the grooves. The ribs can be used as possible

[0021] The course shapes can be straight, curved, meandering, zigzag, angled or lattice-shaped, whereby the ditches can therefore take on a corresponding course.

[0022] In particular, it can be provided that the trenches cross the embossed elevation, so that the opposite trench openings each open into different sections of the same side edge or into opposite side edges of the embossed structure.

[0023] By having the grooves or, accordingly, the ribs traverse the embossed elevation, i.e., extend from one side edge to an opposite side edge of the embossed elevation, this ensures that the pressing surfaces extend right up to the edge of the embossed elevation and, at the same time, achieves the greatest possible distribution of the bonding elevations within the embossed surface. The groove openings point away from the embossed elevation in the direction of rib propagation. The side edges of the embossed structure therefore have alternating ribs and grooves in profile view. Similarly, both groove openings can be arranged to open on the same side of the embossed structure, provided the groove and / or the embossed elevation have a curved shape.

[0024] It may be provided that the bonding protrusions have an arcuate cross-section on their upper side. Alternatively, it may be provided that only the outer edges of the bonding protrusions facing the grooves surrounding the bonding protrusions are rounded.

[0025] Furthermore, it can be provided that the ribs are rounded downwards at their opposite rib ends, which are adjacent to at least one side edge of the embossed structure. Thus, the ribs can have a flattened profile directed toward the outside on their outer sides, which lie in the direction of rib propagation.

[0026] In a particularly pronounced variant of a rounded profile, it can thus be provided that the ribs have a convex profile along their rib propagation direction.

[0027] By eliminating sharp edges by providing rounded edges, the creation of sharp-edged transitions in the tissue paper is avoided, which ensures or maintains high stability of the tissue paper even with a high pressing surface area.

[0028] It can also be provided that the ribs have interruptions running essentially perpendicular to the direction of rib propagation to further reduce the pressing surface. The interruptions can be arranged as slot-shaped openings between the ribs. The openings can be recessed to the level of the embossed elevation opposite the ribs.

[0029] It can be provided that the interruptions are regularly or irregularly spaced from each other by a distance between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm.

[0030] In particular, it can be provided that the embossed elevation has a main propagation direction, with the gluing elevations extending in a direction deviating from the main propagation direction. However, it is conceivable that the gluing elevations also extend in the main propagation direction in some sections, for example, if the embossed elevation has a curved shape.

[0031] It is conceivable that the embossed elevation is a linear ridge. The linear ridge can have straight sections, curved or angled sections, and intersection points where the ridge crosses itself or crosses other linear ridges. The linear ridge can, in particular, have a constant width in the direction of travel. Likewise, the gluing elevations can have a constant width transverse to their main direction of extension. If the gluing elevations are designed as ribs, they can have the same width as the grooves formed between them.

[0032] The invention further relates to an embossing roller having an embossing structure according to one of the preceding claims. The embossing roller may not have any further elevations with the embossing height of the embossing structure or a greater embossing height. Thus, the embossing structure consisting of the embossing elevation and the gluing elevations arranged thereon may represent the highest elevation on the embossing roller. In contrast, it may be provided that either no further embossing structures are provided on the embossing roller or these have a lower Height than the Height of Have an embossed structure, for example for creating micro-embossings.

[0033] It can be provided that the embossing roller has, as an embossing structure, at least two linear ridges, in particular arranged perpendicular to one another, which intersect at at least one intersection point. When providing several linear ridges on the embossing roller, it is conceivable that these are arranged uniformly and regularly on the embossing roller, so that they form a grid-like pattern.

[0034] It is conceivable that a first plurality of substantially parallel and / or equidistant webs and a second plurality of substantially parallel and / or equidistant webs are provided, wherein the second plurality of webs is perpendicular to the first plurality of webs, wherein the intersection points are each arranged equidistant from the intersection points surrounding them.

[0035] The invention further relates to a tissue product which has an embossed motif extending over at least one embossed surface, wherein the embossed surface has a plurality of gluing impressions, in particular uniformly formed and regularly distributed over the embossed surface, with a smaller area proportion than the embossed surface, in particular between 4-20%, preferably 10-14%, particularly preferably 12% of the embossed surface. It can be provided that the distances between the gluing impressions are each between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm. It can also be provided that the tissue product also has micro-embossings in addition to the embossed motif. Furthermore, it can be provided that the embossed motif is highlighted in color. In contrast, it can be provided that micro-embossings are colorless.

[0036] The invention further relates to a method for producing an embossing roller according to one of claims 11 to 13, comprising the steps: a. Providing an embossing roller; b. Applying at least one embossed elevation to the embossing roller, wherein the embossed elevation has a substantially smooth surface; c. Processing the surface of the embossed elevation by means of an abrasive, additive, machining, or forming manufacturing process to produce a plurality of adjacent bonding elevations on the surface of the embossed elevation, wherein the bonding elevations are raised relative to the embossed elevation and provide a smaller pressing surface relative to the embossed surface.

[0037] Further properties, advantages and features of the invention can be seen in the following description of preferred embodiments of the invention with reference to the accompanying drawings, in which: Fig. 1: a perspective view of an embossing roller surface with applied embossed structure; Fig. 2: a tissue product with applied embossed motif and micro-embossing; Fig. 3a-c: a side view and two top views of two different embodiments of the embossed structure according to the invention.

[0038] Figure 1shows the embossed structure 1 according to the invention, which is applied to the surface of an embossing roller 2 and is designed to produce a puzzle-shaped embossed motif 5. The embossed structure 1 comprises, as embossed elevations 4, a first plurality of linear webs 14, which run essentially in a first direction, and a second plurality of linear webs 15, which run essentially in a second direction, wherein the second direction is perpendicular to the first direction. The linear webs 14, 15 are each arranged equidistant from one another and overlap at intersection points 13. The webs each have a main propagation direction X, wherein it can be seen that the linear webs 14, 15 have puzzle-typical bulges between the intersection points 13 in the illustrated embodiment, in which bulges the line course deviates from the main propagation direction X.After embossing the tissue paper, the total surface area of ​​the embossed elevations 4 essentially corresponds to that of the embossed motif produced. On the embossed elevations 4, rib-shaped gluing elevations 6 are provided, essentially perpendicular to the direction of travel, i.e., in the rib propagation direction Y, which can also be described as a ripple structure. The ribs 6 are spaced apart from one another and form grooves 7 between them, wherein it can be seen that both the ribs 6 and the grooves 7 each span the embossed elevation 4 over their entire width BP, so that the groove openings 8 directed towards the outer sides of the embossed structure 1 each open into the side edges 9, 10 of the embossed structure 1. The sum of the surfaces of the gluing elevations 6 ultimately results in the pressing surface or gluing surface B, over which the tissue layer processed with the embossing roller 2 is adhered to the at least one adjacent tissue layer.It is clearly visible that area B is significantly smaller than area A, which makes it possible to create large-scale embossed motifs.

[0039] Figure 2 shows an example of a embossing roller 2 from Figure 1 manufactured tissue product 3, which has the corresponding characteristic embossed motif 5 in the form of a puzzle. The tissue product 3 essentially has three distinguishable regions, on the one hand the regions which are not covered by the embossed motif 5 from Figure 1provided with micro-embossings 12 are arranged. On the other hand, the area A of the embossed motif 5 and the gluing impressions 16 arranged therein, the totality of which represents the gluing area or pressing area B. It is noticeable that the gluing impressions 16 run in the Y direction, i.e. perpendicular to the main propagation direction X of the lines of the embossed motif 5 created by the embossed elevations 4. This relationship is only deviated from in the curved profiles of the embossed motif 5 and at intersection points 13 of the essentially perpendicular embossed motif lines, at which points it can be provided locally that the gluing impressions 16 run in the same direction as the embossed motif lines.

[0040] Figure 3 shows two different embodiments of the embossed structure 1, where Figure 3a a side view of an embossed structure 1 and the Figures 3b and 3ceach represent top views of an embossed structure 1. The side view of the embossed structure 1 in Figure 3ashows that the embossed structure 1 has, on the one hand, an embossed elevation 4 with a first height H1 and a plurality of gluing elevations 6 arranged on the embossed elevation 4, wherein the gluing elevations 6 each have a second height H2, so that the total height of the embossed structure 1 results from the sum of the heights H1 and H2. Furthermore, it can be seen that the embossed structure 1 has a longitudinal extent LR and the gluing elevations 6 each have a width BR. In the embodiment shown, the gluing elevations 6 each have a rectangular cross-section, but can also have different cross-sections, for example trapezoidal or rounded at the top. Between the gluing elevations 6, trenches 7 are formed, which open with their opposite trench openings 8 into the side edges 9, 10 of the embossed structure 1. In other words, the embossed elevation 4 is spanned by the gluing elevations 6 in its full width BP.. Figure 3a clarifies that the area A of the embossed motif 5 is oriented towards the total surface of the embossed elevation 4. In contrast, the pressing area B results from the sum of the surfaces of the gluing elevations 6. In the example shown, the gluing elevations 6 are parallel to one another and have a regular spacing. In this and corresponding embodiments, the pressing area portion thus results from the ratio of a gluing elevation surface to the distance between two adjacent gluing elevations 6.

[0041] The Figure 3b The embodiment shown has as gluing elevations 6 the ones already shown in Figure 3ashown linear ribs, which run perpendicular, ie in the Y-direction, to the propagation direction X of the embossed elevation 4, are arranged parallel to each other, have a regular distance from each other and span the embossed elevation 4 over its full width BP, so that the length of the ribs corresponds to the width BP of the embossed elevation 4. The also regularly spaced trenches 7 each open on opposite side edges 9, 10 of the embossed structure 1 with respective trench openings 8. The embodiment of the Figure 3b It is particularly well-suited for narrow embossed projections where segmentation of the bonding projections 6 in the Y direction is not necessary. Furthermore, this design is easy to manufacture and cost-effective to produce.

[0042] Figure 3c represents a further embodiment of the embossed structure 1, wherein compared to the Figure 3bIn the embodiment shown, the gluing elevations 6, designed as linear ribs, have regular interruptions 11, which thereby segment individual rib elements from one another in the Y direction. The interruptions 11 run perpendicular to the rib propagation direction Y and, compared to these, have a reduced height, which can extend down to the level of the embossed elevation 4. By segmenting the pressing surface not only in the propagation direction of the embossed elevation, but also perpendicular to it, the pressing surface portion of the gluing elevations 6 can be further reduced or a more regular distribution of the elevations is achieved.

[0043] Further advantageous embodiments are described in the following clauses: 1. Embossing structure (1) for an embossing roller (2) for gluing tissue products (3), which has at least one embossing elevation (4) with an embossing surface (A) for producing an embossed motif (5), characterized in that a plurality of gluing elevations (6) are arranged on the embossing elevation (4), which are raised relative to the embossing elevation (4) and provide a smaller pressing surface (B) relative to the embossing surface (A). 2. Embossing structure (1) according to clause 1, wherein the pressing surface portion provided by the gluing elevations (6) is less than 20%, preferably less than 10%, particularly preferably less than or equal to 6% of the embossing surface (A). 3. Embossing structure (1) according to clause 1 or 2, wherein the gluing elevations (6) are uniformly formed and regularly distributed over the embossing surface (A). 4.Embossed structure (1) according to one of the preceding clauses, wherein the gluing elevations (6) are linear ribs between which grooves (7) are formed, wherein the pressing surface (B) is segmented by the grooves (7). 5. Embossed structure (1) according to clause 4, wherein the grooves (7) traverse the embossed elevation (4) so ​​that the opposite groove openings (8) each open into different sections of the same side edge (9) or into opposite side edges (9, 10) of the embossed structure (1). 6. Embossed structure (1) according to one of the preceding clauses, wherein the gluing elevations (6) have an upwardly curved cross-section. 7. Embossed structure (1) according to one of clauses 4 to 6, wherein the ribs have interruptions (11) extending substantially perpendicular to the rib propagation direction (Y) to further reduce the pressing surface (B).Embossed structure (1) according to clause 7, wherein the interruptions (11) are regularly or irregularly spaced from one another by a distance between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm. 9. Embossed structure (1) according to one of the preceding clauses, wherein the embossed elevation (4) has a main propagation direction (X), wherein the gluing elevations (6) extend in a direction deviating from the main propagation direction (X). 10. Embossed structure (1) according to clause 9, wherein the embossed elevation (4) is a linear web. 11. Embossing roller (12) having an embossed structure (1) according to one of the preceding clauses, wherein the embossed roller (12) has no further elevations with the embossing height (H3) of the embossed structure (1) or a greater embossing height.Embossing roller (12) according to clause 11, which, as an embossing structure (1), has at least two, in particular perpendicularly arranged, linear webs which intersect at at least one intersection point (13). 13. Embossing roller (12) according to clause 12, which has a first plurality (14) of substantially parallel and / or equidistant webs and a second plurality (15) of substantially parallel and / or equidistant webs, wherein the second plurality (15) of webs is perpendicular to the first plurality (14) of webs, wherein the intersection points (13) are each arranged equidistant from the surrounding intersection points (13). 14.Tissue product (3) having an embossed motif extending over at least one embossed surface (A), wherein the embossed surface (A) has a plurality of gluing impressions (16), in particular uniformly formed and regularly distributed over the embossed surface, with a gluing area (B) that is smaller than the embossed surface (A), in particular between 4-20%, preferably 10-14%, particularly preferably 12% of the area share of the embossed surface (A). 15. Method for producing an embossing roller (2) according to one of clauses 11 to 13, comprising the steps: a. providing an embossing roller (2); b. applying at least one embossed elevation (4) to the embossed roller (12), wherein the embossed elevation (4) has a substantially smooth surface; c.Processing the surface of the embossed elevation (4) by means of an abrasive, additive, machining or forming manufacturing process to produce a plurality of gluing elevations (6) on the surface of the embossed elevation (4), wherein the gluing elevations (6) are raised relative to the embossed elevation (4) and provide a pressing surface (B) that is smaller than the embossed surface (A).

[0044] The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the realization of the invention both individually and in any combination. List of reference symbols

[0045] 1Embossed structure 2Embossed roller 3Tissue product 4Embossed elevation 5Embossed motif 6Gluing elevations 7Trenches 8Trench openings 9Side edge 10Side edge 11Interruptions 12Micro embossings 13Intersection 14First plurality of webs 15Second plurality of webs 16Gluing impressions AEmbossed surface BPressing surface / Gluing surface H1Height of embossed elevation H2Height of gluing elevation LRLength of embossed structure BRRib width BPWidth of embossed structure XMain propagation direction of embossed elevation YRib propagation direction

Claims

1. Embossing structure (1) for an embossing roller (2) for gluing tissue products (3), which has at least one embossed elevation (4) with an embossed surface (A) for producing a linear embossed motif (5), characterized in that a plurality of, optionally evenly distributed, gluing elevations (6) are arranged on the embossed elevation (4), which are raised relative to the embossed elevation (4) and provide a pressing surface (B) that is smaller than the embossed surface (A).

2. Embossed structure (1) according to claim 1, wherein the pressing surface portion provided by the gluing elevations (6) is less than 20%, preferably less than 10%, particularly preferably less than or equal to 6% of the embossed surface (A).

3. Embossed structure (1) according to claim 1 or 2, wherein the gluing elevations (6) are uniformly formed and regularly distributed on the embossed surface (A).

4. Embossed structure (1) according to one of the preceding claims, wherein the gluing elevations (6) are linear ribs between which grooves (7) are formed, wherein the pressing surface (B) is segmented by the grooves (7).

5. Embossed structure (1) according to claim 4, wherein the trenches (7) traverse the embossed elevation (4) such that the opposite trench openings (8) each open into different sections of the same side edge (9) or into opposite side edges (9, 10) of the embossed structure (1).

6. Embossed structure (1) according to one of the preceding claims, wherein the gluing elevations (6) have an upwardly curved cross-section.

7. Embossed structure (1) according to one of claims 4 to 6, wherein the ribs have interruptions (11) running substantially perpendicular to the rib propagation direction (Y) to further reduce the pressing surface (B).

8. Embossed structure (1) according to claim 7, wherein the interruptions (11) are regularly or irregularly spaced from one another by a distance between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm.

9. Embossed structure (1) according to one of the preceding claims, wherein the embossed elevation (4) has a main propagation direction (X), wherein the gluing elevations (6) extend in a direction deviating from the main propagation direction (X).

10. Embossed structure (1) according to claim 9, wherein the embossed elevation (4) is a linear web.

11. Embossing roller (12) having an embossed structure (1) according to one of the preceding claims, wherein the embossing roller (12) has no further elevations with the embossing height (H3) of the embossed structure (1) or a greater embossing height.

12. Embossing roller (12) according to claim 11, which has as embossing structure (1) at least two, in particular perpendicularly arranged, linear webs which intersect at at least one intersection point (13).

13. Embossing roller (12) according to claim 12, which has a first plurality (14) of substantially parallel and / or equidistant webs and a second plurality (15) of substantially parallel and / or equidistant webs, wherein the second plurality (15) of webs is perpendicular to the first plurality (14) of webs, wherein the intersection points (13) are each arranged equidistant from the intersection points (13) surrounding them.

14. Tissue product (3) which has an embossed motif extending over at least one embossed surface (A), wherein the embossed surface (A) has a plurality of linear gluing impressions (16), in particular uniformly formed and regularly distributed on the embossed surface, with a gluing area (B) which is smaller than the embossed surface (A), in particular between 4-20%, preferably 10-14%, particularly preferably 12% of the area share of the embossed surface (A).

15. A method for producing an embossing roller (2) according to one of claims 11 to 13, comprising the steps: (a) providing an embossing roller (2); (b) applying at least one embossing elevation (4) to the embossing roller (12), wherein the embossing elevation (4) has a substantially smooth surface; (c) machining the surface of the embossing elevation (4) by means of an abrasive, additive, machining or forming manufacturing process to produce a plurality of gluing elevations (6) on the surface of the embossing elevation (4), wherein the gluing elevations (6) are linear and raised relative to the embossing elevation (4) and provide a pressing surface (B) that is smaller than the embossing surface (A).

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