EP4032695A1 - 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 - Google Patents

Abstract

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

Description

The invention relates to an embossing structure for an embossing roll for gluing tissue products, which has at least one embossing elevation with an embossing surface for producing an embossing motif. A corresponding embossing roller, a corresponding tissue product and a method for producing an embossing roller having the embossing structure are also described.

From the EP 1319 748 B9 if an embossed tissue paper or an embossing tool for its production is known, the embossing tool for design purposes having a first group of large, widely spaced embossing elevations and a second group of smaller, more closely spaced embossing elevations compared to the first group, which are arranged on a pedestal, so that the tops of the first and second embossments are on the same plane and provide a common pressing surface.

the WO 2008/132612 A1 discloses an embossing roll for a paper substrate having an embossing surface having an emboss line element and a step extending longitudinally or transversely of the emboss line element and disposed adjacent one of two opposite edges at the upper end of the emboss line element. The aim of the device disclosed is to produce particularly clear embossed edges in order to give the customer a qualitative impression.

the EP 1209 289 B1 discloses an apparatus for producing absorbent crepe paper. The device has an embossing roller with a convex cylindrical surface for producing micro-embossing. A plurality of pegs shaped in relief are arranged on the cylindrical surface, each of the pegs consisting of a truncated pyramid-shaped base with a rectangular base plate and a flattened apex or free end part.

Tissue products such as toilet paper or kitchen rolls are often made up of several layers of tissue. The at least one top layer and the at least one bottom layer are each embossed in the embossing gap between a positively engraved steel roller and a smooth, rubber-coated backing roller in such a way that the resulting raised embossed figures face each other.

In order to join the layers together, glue is applied to the raised tissue structure of the tissue still on an embossing roller with the aid of a gluing unit.

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

Furthermore, it is common for the entire pressing surface of the embossing design to be wetted with glue. This leads to the surfaces wetted with glue hardening, to the fact that the consumption of glue is comparatively high and that, in the case of high pressing surface areas, the layers cannot be sufficiently bonded despite the large amount of glue transferred.

In these cases, insufficient adhesion is due to the fact that, due to the large proportion of pressing surface, the overall pressure in the gluing position is not sufficient to achieve the specific pressure at the point to be glued.

The resulting constraint not to exceed a critical press area prevents the development of aesthetically pleasing designs that would require high press area.

Practice has shown that problems with the adhesion of the plies occur with high proportions of pressing surfaces, and the continuous areas of glue on the pressing surfaces create a relatively high resistance to deformation of the tissue product, which is felt to be hard and uncomfortable.

Devices known from the prior art for producing tissue products are therefore subject to a technical limit as far as the pressing surface area of designs is concerned, as a result of which the range of possible designs for tissue paper is severely limited.

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 end product and aesthetically pleasing designs with high pressing surface areas are made possible.

The object is solved with the features of the independent claims.

Accordingly, provision is made for a plurality of gluing elevations to be arranged on the embossing elevation, which elevations are higher than the embossing elevation and provide a smaller pressing surface than the embossing surface.

The embossed elevation can be set up in particular to produce a visible embossed motif, in particular one with a large motif, on the tissue product. For this purpose, the embossed elevation can have a constant first height. The embossing motif can be highlighted in color compared to the rest of the tissue, for example. The gluing elevations can be applied to the upper side of the embossing elevation or can be produced by removing material from the embossing structure. Starting from the height of the embossing elevations, the gluing elevations can be raised by a second height above the first height. In particular, the gluing elevations have the purpose or advantage of producing relatively small pressing surfaces within the relatively large embossing surface, via which reliable adhesion between the at least two tissue plies is made possible. The pressing surface can essentially correspond to the base surface of the embossing elevation.

On the other hand, the pressing area can be the sum of the surfaces of all the gluing bumps on the embossing bump. The overall height of the embossed structure results from the sum of the first height of the embossing elevation and the second height of the gluing elevations.

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

Provision can be made for the gluing elevations to be formed uniformly and distributed regularly on the embossing surface. The gluing elevations can be linear and parallel, for example. The lines can be curved or jagged. Alternatively, the lines can cross. Furthermore, as an alternative, provision can be made for the gluing elevations to be arranged at certain points on the embossing elevation. These punctiform gluing elevations can have different shapes and can be, for example, square, round, oval, in the form of a flower pattern or similar. It is particularly advantageous if the gluing elevations extend over the entire embossing surface of the embossing elevation and are, for example, evenly spaced from one another.

Provision can be made for the gluing elevations to be linear ribs between which trenches are formed, with the pressing surface being segmented by the trenches. The segmentation of the pressing surface pursues the goal of breaking up the pressing surfaces by introducing parallel lines, in particular into individual surfaces that are independent of one another. The trenches can extend to the level of the first height of the embossing. The side walls of the trenches can be defined by the ribs respectively surrounding the trenches. The ribs can as possible

Course shapes can be straight, curved, meandering, zigzag, angled or grid-like, with the trenches being able to assume a corresponding course as a result.

In particular, it can be provided that the trenches traverse the embossed elevation, so that the opposite trench openings open out in different sections of the same side edge or in opposite side edges of the embossed structure.

Since the trenches or correspondingly the ribs also traverse the embossed elevation, i.e. extend from one side edge to an opposite side edge of the embossed elevation, it is ensured that the pressing surfaces reach up to the edge of the embossed elevation on the one hand and have the greatest possible distribution on the other of the gluing elevations within the embossing area. The trench openings point away from the embossed elevation in the rib propagation direction. The side edges of the embossed structure accordingly have alternating ribs and trenches in a profile view. In the same way, it can be provided that both trench openings end on the same side of the embossed structure if the trench and/or the embossed elevation has a curved course.

Provision can be made for the gluing elevations to have an arcuate cross section on their upper side. Alternatively, it can be provided that in each case only the outer edges of the gluing elevations directed towards the trenches surrounding the gluing elevations are rounded.

Furthermore, it can be provided that the ribs are rounded downwards at their opposite rib ends which abut at least one side edge of the embossed structure. The ribs can thus have a flattening profile on their outer sides lying in the rib propagation direction.

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.

By dispensing with sharp edges through the provision of roundings, the production of sharp-edged transitions in the tissue paper is avoided, as a result of which high stability of the tissue paper is ensured or maintained even with a high percentage of pressing surface.

Provision can furthermore be made for the ribs to have interruptions running essentially perpendicularly to the direction of propagation of the ribs in order to further reduce the pressing surface. The interruptions can be arranged as slit-shaped openings between the. The openings can be deepened down to the level of the embossed elevation opposite the ribs.

Provision can be made for the interruptions to be spaced apart from one another regularly or irregularly by a distance of between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm.

In particular, it can be provided that the embossing elevation has a main propagation direction, with the gluing elevations running in a direction deviating from the main propagation direction. However, it is conceivable that the gluing elevations also run in the main propagation direction in sections, for example if the embossing elevation has a curve.

It is conceivable that the embossed elevation is a linear web. It can be provided that the linear web has straight sections, curved or angled sections and intersections at which the web crosses itself or other linear webs crosses. The linear web can in particular have a constant width in the direction of extent. Provision can also be made for the gluing elevations to have a constant width transversely to their main direction of propagation. When the gluing elevations are designed as ribs, it can be provided that these have the same width as the trenches formed between them.

The invention further relates to an embossing roller having an embossing structure according to any one of the preceding claims. In this case, the embossing roller cannot have any further elevations with the embossing height of the embossing structure or a greater embossing height. The embossing structure consisting of the embossing elevation and the gluing elevations arranged thereon can thus represent the highest elevation on the embossing roller. In contrast, it can be provided that either no further embossing structures are provided on the embossing roller or these have a lower height than the height of the embossing structure, for example for producing micro-embossing.

Provision can be made for the embossing roller to have at least two linear webs as an embossing structure, in particular arranged perpendicular to one another, which intersect at at least one point of intersection. If several linear webs are provided 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 grid.

It is conceivable that a first plurality of essentially parallel and/or equidistant webs and a second plurality of essentially parallel and/or equidistant webs are provided, the second plurality of webs being perpendicular to the first plurality of webs, with the intersection points each being equidistant to the these surrounding intersections are arranged.

The invention further relates to a tissue product which has an embossing motif extending over at least one embossing area, the embossing area having a plurality of gluing impressions, in particular uniformly formed and regularly distributed on the embossing area, with a smaller, in particular between 4-20%, compared to the embossing area. , preferably 10-14%, particularly preferably 12% of the embossing area, surface proportion. It can be provided that the distances between the impressions of the glue are between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm. Provision can also be made for the tissue product to have micro-embossings in addition to the embossing 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.

1. a. Bereitstellen einer Prägewalze;
2. b. Aufbringen von zumindest einer Prägeerhebung auf die Prägewalze, wobei die Prägeerhebung eine im Wesentlichen glatte Oberfläche aufweist;
3. c. Bearbeiten der Oberfläche der Prägeerhebung mittels eines abtragenden, additiven, zerspanenden oder umformenden Fertigungsverfahrens zur Erzeugung einer Mehrzahl benachbarter Verleimungserhebungen auf der Oberfläche der Prägeerhebung, wobei die Verleimungserhebungen gegenüber der Prägeerhebung erhöht sind und eine gegenüber der Prägefläche kleinere Pressfläche bereitstellen.

The invention also relates to a method for producing an embossing roller according to one of claims 11 to 13, comprising the steps:

1. a. providing an embossing roller;
2. b. applying at least one embossing bump to the embossing roll, the embossing bump having a substantially smooth surface;
3. c. Machining the surface of the embossed elevation by means of an ablative, additive, machining or forming manufacturing process to produce a plurality of adjacent glued elevations on the surface of the embossed elevation, the glued elevations being higher than the embossed elevation and providing a pressing surface that is smaller than the embossing surface.

Fig. 1

eine perspektivische Darstellung einer Prägewalze Oberfläche mit aufgebrachter Prägestruktur;

Fig. 2

ein Tissueprodukt mit aufgebrachtem Prägemotiv und Mikroprägungen;

Fig. 3a-c

eine Seitenansicht und zwei Draufsichten zwei unterschiedliche Ausführungsformen der erfindungsgemäßen Prägestruktur.

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:

1

a perspective view of an embossing roller surface with applied embossing structure;

2

a tissue product with applied embossing motif and micro-embossing;

Fig. 3a-c

a side view and two plan views of two different embodiments of the embossing structure according to the invention.

figure 1 shows the embossing 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 embossing motif 5 . The embossed structure 1 comprises, as embossed elevations 4, a first plurality of linear webs 14, which essentially run in a first direction, and a second plurality of linear webs 15, which essentially run in a second direction, the second direction being perpendicular to the first direction . The linear webs 14, 15 are each arranged equidistantly from one another and intersect at intersections 13. The webs each have a main propagation direction X, it being evident that the linear webs 14, 15 between the intersections 13 in the illustrated embodiment have jigsaw-type bulges , in which the course of the line deviates from the main propagation direction X. After the tissue paper has been embossed, the total surface area A of the embossed elevations 4 essentially corresponds to that of the embossed motif produced. Rib-shaped gluing elevations 6 are provided on the embossed elevations 4 essentially perpendicularly to the direction of extension, ie in the direction of rib propagation Y, which can also be described as a corrugated structure. The ribs 6 are spaced apart and form between them Trenches 7, it being seen that both the ribs 6 and the trenches 7 each span the embossing elevation 4 over its entire width BP, so that the trench openings 8 directed to the outside of the embossed structure 1 are in the side edges 9, 10 of the embossed structure 1 flow. The sum of the surfaces of the gluing elevations 6 ultimately results in the pressing surface or gluing surface B, via which the tissue ply processed with the embossing roller 2 is bonded to the at least one adjacent tissue ply. It is easy to see that area B is significantly smaller than area A, which makes it possible to create large-area embossed motifs.

figure 2 shows an example with the embossing roller 2 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 those that do not have the embossed motif 5 figure 1 provided area in which micro-embossings 12 are arranged. On the other hand, the surface A of the embossed motif 5 and the gluing impressions 16 arranged therein, the entirety of which represents the gluing surface or pressing surface B. It is noticeable that the gluing impressions 16 run in the Y direction, ie perpendicular to the main propagation direction X of the lines of the embossed motif 5 produced by the embossed elevations 4 . The only deviation from this relationship is in curves of the embossed motif 5 and at intersections 13 of the embossed motif lines essentially perpendicular to one another, at which points it can be provided locally that the glue impressions 16 run in the same direction as the embossed motif lines.

figure 3 shows an example of two different embodiments of the embossed structure 1, wherein Figure 3a a side view of an embossing structure 1 and the Figures 3b and 3c each represent top views of an embossing structure 1 . The side view of the embossing structure 1 in Figure 3a shows that the embossed structure 1 has an embossed elevation 4 with a first height H1 and a plurality of gluing elevations 6 arranged on the embossing elevation 4, with the gluing elevations 6 each having a second height H2, so that the total height of the embossed structure 1 is the sum of the heights H1 and H2. It can also be seen that the embossed structure 1 has a length extension LR and the gluing elevations 6 each have a width BR. In the illustrated embodiment, the gluing elevations 6 each have a rectangular cross-section, but they can also have different cross-sections, for example trapezoidal or rounded at the top. Trenches 7 are formed between the gluing elevations 6 and open into the side edges 9 , 10 of the embossed structure 1 with their opposite trench openings 8 . In other words, the embossing elevation 4 is spanned over its full width BP by the gluing elevations 6 . Figure 3a makes it clear that the area A of the embossed motif 5 is based on the entire surface of the embossed elevation 4 . In contrast, the pressing surface 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 from one another. In this and in corresponding embodiments, the proportion of the pressing surface results from the ratio of a gluing elevation surface to the distance between two adjacent gluing elevations 6.

In the Figure 3b The embodiment shown has the gluing elevations 6 already shown in Figure 3a linear ribs shown, which run perpendicularly, i.e. in the Y direction, to the direction of propagation X of the embossed elevation 4, are arranged parallel to one another, have a regular spacing from one another and span the embossed elevation 4 over its full width BP, so that the length of the ribs is Width BP of embossing bump 4 corresponds. Trenches 7, which are also regularly spaced, open out on opposite side edges 9, 10 of embossed structure 1 with respective trench openings 8. The embodiment of FIG Figure 3b is particularly well suited for narrow embossing elevations where a segmentation of the gluing elevations 6 in the Y-direction is not necessary. Furthermore, this embodiment is easy to manufacture and inexpensive to produce.

Figure 3c represents a further embodiment of the embossing structure 1, in which compared to the Figure 3b 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 perpendicularly to the rib propagation direction Y and have a reduced height compared to this, which can reach down to the level of the embossed elevation 4 . By segmenting the pressing surface not only in the propagation direction of the embossing elevation, but also perpendicular to it, it is achieved that the pressing surface portion of the gluing elevations 6 is even greater can be reduced or a more regular distribution of the surveys can be achieved.

The features of the invention disclosed in the above description, in the drawings and in the claims can be essential for the realization of the invention both individually and in any combination.

Reference List

1

embossing structure

2

embossing roller

3

tissue product

4

embossing elevation

5

embossed motif

6

gluing surveys

7

ditches

8th

ditch openings

9

side edge

10

side edge

11

interruptions

12

micro embossing

13

intersection

14

first plurality of bars

15

second plurality of webs

16

gluing impressions

A

embossing surface

B

Pressing surface/ gluing surface

H1

Height of embossing

H2

Amount of gluing survey

LR

Length embossed structure

BR

rib width

bp

Wide embossed structure

X

Main direction of propagation embossing elevation

Y

rib propagation direction

Claims (15)

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 embossing motif (5), characterized in that on the embossing elevation (4) a plurality of gluing elevations (6) are arranged, which are higher than the embossing elevation (4) and provide a pressing surface (B) that is smaller than the embossing surface (A). Embossing structure (1) according to claim 1, wherein the proportion of pressing surface 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). Embossing structure (1) according to Claim 1 or 2, in which the gluing bumps (6) are formed uniformly and are regularly distributed on the embossing surface (A). Embossing structure (1) according to one of the preceding claims, in which the gluing elevations (6) are linear ribs between which trenches (7) are formed, the pressing surface (B) being segmented by the trenches (7). Embossing structure (1) according to claim 4, wherein the trenches (7) traverse the embossing elevation (4) so that the opposite trench openings (8) are respectively in different sections of the same side edge (9) or in opposite side edges (9, 10) of the embossing structure ( 1) flow. Embossing structure (1) according to any one of the preceding claims, in which the gluing bumps (6) have an upwardly arcuate cross-section. Embossing structure (1) according to any one of claims 4 to 6, wherein the ribs to further reduce the pressing surface (B) substantially perpendicular to Rib propagation direction (Y) running interruptions (11). Embossing structure (1) according to Claim 7, in which the interruptions (11) are regularly or irregularly spaced from one another by a distance of between 0.1 mm and 10 mm, preferably between 0.2 mm and 1.0 mm. Embossing structure (1) according to any one of the preceding claims, wherein the embossing bump (4) has a main propagation direction (X), the gluing bumps (6) running in a direction deviating from the main propagation direction (X). Embossed structure (1) according to Claim 9, in which the embossed elevation (4) is a linear web. Embossing roller (12) having an embossing 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 embossing structure (1) or a greater embossing height. Embossing roller (12) according to Claim 11, which has at least two linear webs, in particular arranged perpendicularly to one another, as the embossing structure (1), which intersect at at least one point of intersection (13). Embossing roller (12) according to claim 12, which has a first plurality (14) of substantially parallel and/or equidistant lands and a second plurality (15) of substantially parallel and/or equidistant lands, the second plurality (15) of lands perpendicular to the first plurality (14) is webs, the points of intersection (13) being arranged equidistant to the points of intersection (13) surrounding them. Tissue product (3) which has an embossing motif extending over at least one embossing area (A), the embossing area (A) having a plurality of, in particular uniformly formed and regularly on the Gluing impressions (16) with a smaller gluing area (B) compared to the embossing area (A), in particular between 4-20%, preferably 10-14%, particularly preferably 12% of the area proportion of the embossing area (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), the embossing elevation (4) having a substantially smooth surface; c. Machining the surface of the embossed elevation (4) by means of an ablative, additive, machining or forming manufacturing process to produce a plurality of glued elevations (6) on the surface of the embossed elevation (4), the glued elevations (6) being higher than the embossed elevation (4) and provide a pressing surface (B) that is smaller than the embossing surface (A).

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