ES2949012T3 - Embossing roller arrangement for producing tissue papers of at least two layers and method for producing an embossing roller arrangement - Google Patents

Abstract

Arrangement of embossing rollers for the production of paper tissues of at least two layers, such as in particular handkerchiefs and/or napkins and/or kitchen rolls and/or toilet paper, with a pair of rollers rolling one over the other, presenting the pair of rollers an embossing roller. roller and a counterroller, and with at least one embossing arrangement formed in the pair of rollers, wherein the embossing arrangement in the counterroller comprises a recess and in the embossing roller a projection that engages in the recess, the recess having a stamping edge surrounding the recess opening and the projection having at least partially angled side flanks with which the projection at least partially forms the stamping edge when immersed in the contacting recess. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Embossing roller arrangement for producing tissue papers of at least two layers and method for producing an embossing roller arrangement

The invention relates to an embossed roller arrangement for producing at least two-ply tissue papers, such as in particular paper handkerchiefs and/or paper napkins and/or kitchen rolls and/or toilet paper, with a pair of rollers that They roll one over the other, the pair of rollers comprising an embossing roller and a counter roller, and with at least one embossing arrangement configured on the pair of rollers, the embossing arrangement on the opposite roller comprising at least one notch and on the embossing roller has at least one projection that enters the recess, the recess having an embossing edge that surrounds the recess opening and the projection presenting at least in sections angled lateral flanks, with which the projection comes into contact at least in sections with the embossing roller upon entering the recess, the recess having a slope that has at least in the area of the embossing edge a slope angle that is smaller with respect to the vertical than a flank angle of the lateral flanks of the protrusion. The invention also relates to a method for producing an embossing roller arrangement.

For the adhesion of several layers during the production of tissue paper without the use of glue, different types of embossing are known from the state of the art, which differ in particular with regard to the engravings used. For example, joining rollers, top-to-flat or top-to-top rollers are known. In the case of joining rollers, two engraved rollers are manufactured, one of them engraved positively and the other negatively, with the first roller serving as an engraving tool during the engraving of the corresponding opposite roller. Due to this, the stamped figures on the positive roller correspond to the formations on the negative roller and can be inserted into them in a positive connection. The adhesion of the tissue papers is generated in this regard by the pressure that is produced in the annular space when the embossing roller enters the negative roller between the embossed figures and the formations.

In the case of top-to-flat rollers, a positive engraved embossing roller is pressed against a smooth counter roller with high pressure. The pressure of the flat engraving head against the smooth counter roller generates the adhesion of the layers.

Top-to-top rollers are a subset of top-to-flat rollers. In this case, two positive-engraved stamping rollers of the same type are used, in which the stamping elements are arranged oppositely. The required pressure is generated between the smooth heads of the stamping elements against each other.

In all of the embossing configurations described, the multi-ply tissue product is guided through the resulting gap between two rollers and after embossing is further processed to obtain the desired final product.

However, all methods have in common that the effective embossing surface is relatively large and therefore a correspondingly high pressure must be generated to produce the desired layer adhesion. However, this high pressure, which is necessary due to the stamping geometry, carries the risk of damage to the rollers and reduces their useful life. This is accompanied by an increased susceptibility to damage of the rollers due to vibrations. An embossing roller arrangement is known, for example, from US 5,503,896 A. Similar embossing roller arrangements are also known from EP 0338792 A2 or US 2,834,809 A.

The invention is therefore based on the object of providing an embossing roller arrangement or a method for producing such an embossing roller arrangement, in which a significantly lower pressure force between the rollers is necessary. stamping to produce the desired layer adhesion.

This object is achieved by the proposed embossing roller arrangement according to claim 1. Independent claim 12 relates to a corresponding method for producing an embossing roller arrangement. Advantageous embodiments of the invention are respectively the subject of the dependent claims.

Accordingly, an arrangement of embossing rollers is proposed to produce at least two-ply tissue papers, such as in particular paper handkerchiefs and/or paper napkins and/or kitchen rolls and/or toilet paper, in which case , the flank angle is at a rate of 10 degrees, and particularly preferably 15 degrees, greater than the slope angle. Preferably a plurality of the embossing arrangements are configured on the pair of rollers in a regular, irregular or patterned shape.

By contacting the lateral flanks of the projection only with the stamping edge of the recess and not, as previously, with a large part of the inner surface of the recess, the active stamping surface is reduced, so that also the The pressure force acting on the embossing roller or the counter roller can be reduced while maintaining the specific pressure required for the generation of layer adhesion of the tissue paper layers. The active embossing surface is now reduced from a relatively large surface area, as is known from the prior art, to a very narrow embossing edge. Another advantage of the arrangement according to the invention is that there is no thickening of the stamped material, as occurs, for example, when stamped with bonding roller. In some uses, such as, for example, in the case of paper napkins, which are folded into quarters, due to the thickening of the embossed edge, especially at high stacking heights, an inclined stack results, which is disadvantageous during packaging. and during storage. In contrast, paper napkins printed with the embossing arrangement according to the invention have a perfect flat position after embossing.

The radius of the stamping edge may in particular be between 0.1 mm and 5 mm.

The projection may have a projection height with which the projection moves away from the surface of the embossing roller, the projection narrowing at least in sections in the direction of the upper side of the projection. For example, the projection may be tapered conically. In particular, the projection may have a trapezoidal cross section. Alternatively, the projection can be tapered into a parabola.

In particular, the width of the upper projection side may be narrower and the width of the projection base wider than the width of the recess opening. This configuration means that the projection cannot completely enter the recess and as a result the lateral flanks of the projection come into contact with the stamping edge of the recess starting from a certain insertion width.

For example, the recess may have a rectangular cross section with vertical side walls, so that the slope with respect to the vertical is 0 degrees. Correspondingly, the side flanks on both sides of the projection can respectively have an angle of more than 0 degrees, so that the projection tapers in the direction towards the upper side of the projection. The flank angle of the lateral flanks of the projection is preferably always more than 0 degrees, regardless of the slope angle of the recess. Thus, in an extreme case, the notch may even have a negative slope angle, the projection, however, coming into contact with its lateral flanks with the stamping flank due to its beveled lateral flanks with an angle of more than 0 degrees.

By providing an angular difference between the inclination of the recess and the lateral flanks of the projection or a contact of the lateral flanks with the stamping edge, the arrangement according to the invention has the advantage that, compared to arrangements known from In the state of the art, significantly fewer requirements have to be met with regard to the adjustment of the rollers relative to each other, since the projection is itself centered in the recess. Due to the choice of a particularly large angle difference this effect is reinforced. Due to the choice of a small angle difference, the contact surface between the side flanks and the stamping edge increases, which can be advantageous for certain applications.

Furthermore, the upper protrusion side of the protrusion may be separated from the base of the recess when it enters the recess. This is achieved when the boss is configured such that the side flanks of the boss come into contact with the stamping flank before the upper side of the boss touches the base of the recess. This is therefore influenced by the width and height of the projection, as well as the flank angle of the side flanks and, on the other hand, by the depth of the recess and the width of the recess opening.

Furthermore, the upper projection side may have a plateau. Alternatively, the upper side of the projection may be pointed or rounded.

Furthermore, the projection may be symmetrical in axis with respect to the vertical direction. Furthermore, the projection can be configured as a body rotating around its vertical central axis. Because side flanks with the same flank angles are provided, an inclination of the projection in the housing can in particular be avoided, which has an advantageous effect on the service life of the embossing roller arrangement.

Furthermore, the recess may advantageously be symmetrical in axis with respect to the vertical direction. In particular, the recess may also be configured rotationally symmetrical about its vertical central axis. Particularly preferably, both the recess and the projection are designed with rotational symmetry.

Furthermore, the stamping edge can surround the cutout opening with a round, oval or polygonal shape. Alternatively, the recess can also be configured in the form of a slot. In this regard, the round shape, alternatively also the oval shape, is particularly preferred, since in the case of these shapes the adjustment precision of the rollers relative to each other is the lowest.

Correspondingly, the projection can also have a round, oval or polygonal outer circumference that corresponds to the stamped edge. For the effect of particularly high layer adhesion, it is particularly advantageous that a pressure is achieved along the entire perimeter of the embossing edge.

The lateral flanks of the projection can therefore come into contact with the stamping edge that surrounds the notch opening over the entire circumference of the opening.

Furthermore, the protrusion height may be less than or equal to the recess depth.

Furthermore, a method is claimed for producing an embossing roller arrangement according to one of the preceding claims, comprising embossing at least one embossing arrangement configured on the pair of rollers by means of a direct laser process.

The method may further comprise the separate structuring of embossing roller and counter roller by means of a laser unit using separate control data adapted to the different angles of flank angle and slope angle.

It is not possible to produce different flan angles

negative with classical engraving procedures, such as, for example, those described above for bonding rollers. A stamping arrangement according to the invention can only be achieved in that both rollers are directly structured by means of a suitable laser unit using control data adapted for the specification of the flank angle. Etching is achieved in this regard by direct evaporation of the roller material.

Exemplary embodiments of the invention are explained by the following figures. In this regard it shows:

Figure 1a an arrangement of connecting rollers known from the state of the art;

Figure 1b a top-to-flat roller arrangement known from the state of the art;

Figure 1c a top-to-top roller arrangement known from the state of the art;

Figure 2 a cross-sectional view of an embossing roller according to the invention;

Figure 3 a cross-sectional view of a counter roller according to the invention;

Figure 4 a cross-sectional view of an embossing roller arrangement according to the invention.

Embossing roller arrangements known from the state of the art are shown in Figures 1a to 1c. Figure 1a shows a tie roller arrangement, Figure 1b a top-to-flat roller arrangement and Figure 1c a top-to-top roller arrangement. The bonding roller arrangement has two engraved rollers, of which the embossing roller 2 is positively engraved and the counter roller 3 is negative engraved, with the embossing roller 2 being used as an engraving tool during the engraving of the counter roller 3 Due to this, the projection 6 of the embossing roller 2 corresponds to the notch 5 in the opposite roller and can be inserted when the embossing roller 2 enters the opposite roller 3 in a positive connection therein. The adhesion of multi-ply tissue papers is generated in this case by the pressure resulting from the projection and the recess in the annular space. The top-to-flat roller arrangement of Figure 1 b has a positively engraved embossing roller 2 with projection 6, as well as a flat counter roller 3, the embossing roller 2 being pressed against the smooth counter roller 3 with high pressure. The pressure of the flat engraving head against the smooth counter roller 3 results in the adhesion of layers. The top-to-top roller arrangement of Figure 1c is a subform of the top-to-flat roller arrangement. In this case, two identical positive-engraved stamping rollers 2 are used, in which case the projections 6 of identical configuration are arranged exactly opposite. The required pressure is generated in this case between the smooth engraving heads of the projections 6 against each other.

The cross-sectional view of a projection 6 on an embossing roller 2 shown in FIG. 2 shows a trapezoidal projection 6 with angled side flanks 9 and a plateau 10 or a flat engraving head as the upper side of the projection. With respect to the embossing roller surface, the projection has a height Hv, a width Bvs at the base of the projection 6, as well as a width Bvo on the upper side of the projection. The side flanks 9 each have an angle p with respect to the embossing roller radius.

The cross-sectional view of a recess 5 on a counter roller 3 shown in Figure 3 shows a trapezoidal recess 5 with an inclined slope 11 and a flat recess base. On its upper side or at the level of the surface of the opposite roller, the recess 5 has a recess opening 7, which has an opening width B ^ao . The cutout opening 7 is delimited by a stamping edge 8. The cutout opening 7 is preferably circular, so that the stamping edge 8 surrounds the cutout in a correspondingly circular manner. With respect to the opposite roller surface, the recess 5 has a recess depth T ^a and a width B ^ag of the recess base. The slope 11 of the inner wall of the funnel-shaped recess 5 has an angle a with respect to the opposite roller radius.

The embossing roller arrangement 1 according to the invention is represented in Figure 4. The embossing arrangement 4 is represented at the moment when the embossing roller 2 rolls on the opposite roller 3, in which the projection 6 of the embossing roller The stamping has entered the recess 5 of the counter roller 2 and the side flanks 9 of the projection 6 of the stamping roller 2 are in contact with the stamping edge 8 of the counter roller 3, so that a local pressure is generated there. In the case of a circular cut-out opening 7, a corresponding circular embossing of the multi-layer tissue paper material is therefore produced there. It can be seen that the width Bvo of the upper side of the projection 6 is smaller than the width B ^ao of the notch opening 7 and the width Bvs of the base of the projection 6 is larger than the notch opening 7. In addition, respectively results in a difference of angle p minus a between the angle p of the lateral flanks 9 and the angle a of the slope 11 in the space below the stamping edge 8, of the recess 5. In the example of embodiment shown, both the lateral flanks 9 and Also the slope 11 of the recess funnel are configured flat, so that the angle difference p minus a exists up to the base of the recess 5. Furthermore, the projection 6 has a flat projection upper side or a plateau 10 to avoid a contact between this upper side and the lower part of the recess 5 or to ensure a pressure between the side flanks 9 and the stamping edge 8. There is the possibility of influencing the stamping depth through the width of the projection 6, as well as a modification of the flank angle e.g. By adjusting these parameters, it is determined with what depth the projection 6 enters the recess 5 or at what point on the side flanks 9 the stamping edge 8 comes into contact. In addition, the distance between the surfaces of the embossing roller two and counter roller three. For example, a larger gap can be selected in case of multiple layers of tissue paper and a smaller gap can be generated in case of a smaller number of layers by varying the parameters mentioned above.

The features of the invention disclosed in the above description, in the figures, as well as in the claims may be essential for the implementation of the invention both individually and also in any combination.

Reference list

1 embossing roller arrangement

2 embossing roller

3 counter roller

4 stamping arrangement

5 cutout

6 outgoing

7 cut-out opening

8 stamping edge

9 lateral flanks

10 plateau

11 pending

HV overhang height

BVO width of top side of projection

BVS projection base width

B ^ao width of cutout opening

B ^ag width of the bottom of cutout

T ^at depth of notch

at slope angle

p flank angle

Claims (13)

1. Arrangement of embossing rollers (1) for producing at least two-ply tissue papers, such as in particular paper handkerchiefs and/or paper napkins and/or kitchen rolls and/or toilet paper, with a pair of rollers that They roll one over the other, the pair of rollers comprising an embossing roller (2) and a counter roller (3), and with at least one stamping arrangement (4) configured on the pair of rollers, the stamping arrangement (4) on the opposite roller (3) comprising a notch (5) and on the stamping roller (2) a projection (6 ) that enters the notch, the notch (5) presenting a stamping edge (8) that surrounds the notch opening (7) and the projection (6) presenting, at least in sections, angled lateral flanks (9), with the which the projection (6), upon entering the notch (5), comes into contact at least in sections with the stamping edge (8), the notch (5) presenting a slope (11), which presents at least in the stamping edge area (8), a slope angle (a), which with respect to the vertical is less than a flank angle (p) of the lateral flanks (9) of the projection (6), characterized in that the flank angle (p) is greater than the slope angle (a) by more than 10 degrees, and particularly preferably 15 degrees. 2. Embossing roller arrangement according to claim 1, the projection (6) having a projection height (Hv), with which the projection (6) moves away from the surface of the embossing roller (2), the projection narrowing (6) at least in sections, in the direction of the upper side of the projection. 3. Embossing roller arrangement according to claim 1 or 2, the width (Bvo) of the upper side of the projection being narrower and the width (Bvs) of the base of the projection being wider than the width (B ^ao ) of the opening of notch (7). 4. Embossing roller arrangement according to one of the preceding claims, the upper protruding side of the protrusion (6) being separated from the base of the recess (5) when inserted into the recess (5). 5. Embossing roller arrangement according to one of the preceding claims, the upper protruding side having a plateau (10). 6. Arrangement of stamping rollers according to one of the preceding claims, the projection (6) being symmetrical in axis with respect to the vertical direction. 7. Embossing roller arrangement according to one of the preceding claims, the notch (5) being symmetrical in axis with respect to the vertical direction. 8. Embossing roller arrangement according to one of the preceding claims, the embossing edge (8) surrounding the cut-out opening (7) with a round, oval or polygonal shape. 9. Embossing roller arrangement according to claim 8, the projection (6) having a round, oval or polygonal outer circumference corresponding to the embossing edge (8). 10. Embossing roller arrangement according to claim 8 or 9, the lateral flanks (9) of the projection (6) coming into contact with the embossing edge that surrounds the notch opening (7) over the entire opening circumference. . 11. Embossing roller arrangement according to one of the preceding claims, the protrusion height (Hv) being less than or equal to the notch depth (A ^t ). 12. Method for producing an embossing roller arrangement according to one of the preceding claims, comprising embossing at least one embossing arrangement (4) configured on the pair of rollers by means of a direct laser process. 13. Method according to claim 12, comprising separate structuring of embossing roller (2) and counter roller (3) by means of a laser unit using separate control data adapted to the different angles of flank angle (p) and angle of slope (a).