EP1123799B1 - Method of embossing a sheet-like tissue product, and roller pair to carry out the method - Google Patents

Abstract

To emboss tissue webs, using at least one pair of rollers, the counter roller without a pattern has a diameter which is 0.1-30.0% larger or smaller than the patterned roller. A second embossed pattern is imposed on the tissue, with a surface area of at least 40% of the total embossed pattern surface. The second pattern (7) has a number of pattern points (7a-7g) with pressing surfaces (8a-8g) forming at least 40% of the surface area pressed against the counter roller. The engraved roller is of steel, hard rubber or plastics, and the counter roller is of soft rubber or plastics.

Description

The present invention relates to a pair of rollers with the Features of the preamble of claim 1 and a Method with the features of the preamble of the claim 14th

To tissue articles, in particular kitchen towels, handkerchiefs, Napkins, placemats and / or sanitary towels, so preferably disposable towels and toilet paper, to be provided with certain technical characteristics and / or decoratively, it is known in the context of Produce these web-shaped tissue articles with the help of embossed by at least one pair of rollers. Here can in the known method, the relevant at least one Roller pair of a desired first embossed pattern producing engraved roller, wherein to produce the For the embossing required nip an ungravierte Counter roll is provided. The tissue article to be embossed, the preferably made of paper, is then web-like guided the nip of the roller pair described above and provided there with the desired embossing.

Due to the fact that the engraved roller is a radially after having outside marking and that the web-shaped tissue article, which usually consists of one to four individual layers, has only a limited thickness, occur during the Embossing the pressure surfaces of the engraving in contact with the surface the counter roll. This explains why in the longer Use the counter roll material in the contact area the pressure surfaces of the engraving is considerably damaged, so that due to this damage, which is usually linear extends over the circumference of the counter roll and in one locally limited, significant wear and tear, an exchange the counter roll is required. This problem particularly occurs when the engraved roll has few, has large-format engravings.

A pair of rollers having the features of the preamble of the claim 1 is known from WO 96/18771. Hereby points this pair of rollers an engraved, provided with two engravings Roll on, with a mating roll for embossing the Tissue article required nip forms. To one To emphasize embossing patterns is the relevant engraving Compared to the other engraving, the other embossing pattern generated, formed radially higher. Because of this difference in the radial height of the two engravings occurs increased local wear of the counter roll.

The present invention is based on the object Roller pair and a method for embossing tissue articles to provide a locally limited wear the counter roll is reduced even with prolonged use or even suppressed.

This object is achieved by a pair of rollers the characterizing features of claim 1 and by a method having the characterizing features of the claim 14 solved.

The roller pair according to the invention for embossing a web-shaped Tissue article, in particular for embossing kitchen towels, Handkerchiefs, napkins, placemats and / or sanitary napkins, especially toilet paper and disposable towels, provides that the web-shaped tissue article to be embossed passed through the nip formed by the roller pair becomes. Here, the roller pair according to the invention comprises an engraved roll and hereby forming the nip Counter roller, the engraved roller except the desired first engraving still further a second engraving and the second engraving has a variety of individual engravings each having a small area pressure surface and the first engraving a first embossing pattern and the second engraving a Create second embossing pattern. The counter-roller has a Diameter up, 0.1% to 30% larger or smaller than the diameter of the engraved roll is, with the contact surface the second engraving at least 40% of the counter-roller makes contact in total contact pressure surface and wherein the Individual engravings have a radially outward-facing height, that of the radially outwardly facing height of the first engraving equivalent.

In other words, the roller pair according to the invention is based on three main points, with the first essential point it can be seen that a counter-roller is selected, whose Diameter 0.1% to 30% greater or less than that Diameter of the engraved roller. This will ensure that in the production of the first, desired embossing pattern, which is preferably a large-scale embossed pattern, not always the same area of the surface of the counter roll in Contact with the related first engraving of the engraved Roller occurs, but that this contact area over the circumference the counter roll due to the different diameters is evenly distributed. Alone this is already one Significant reduction in wear of the backing roll, the pressed during the embossing on the engraved roller and thereof transported, ensured.

The second and third essential point of the invention Roller pair, after which the pressure surface of the second engraving at least 40% of the total contact surface coming into contact with the backing roll makes the other areas too the surface of the counter roll through the second engraving, their individual engravings have an identical height as the individual engravings the first engraving, claimed and accordingly be worn, so that a total of uniform wear takes place over the entire surface of the counter roll and therefore punctual, localized areal and / or over the circumference reaching linear damage, the occur relatively quickly in the prior art, avoided become. In other words, the inventive roller pair sure that in contrast to the state of the art here no localized damage and wear of the counter roll can occur because the entire surface of the counter roll on the one hand by the desired first embossing pattern generating the first engraving and the other by the additional provided second embossing pattern generating second Engraving is claimed during embossing. This in total then causes the operating time of a corresponding Counter roll in the inventive roller pair compared to conventional roller pair is considerably higher, so that in particular a life extension of 1.5 times to 3 times occurs.

Such an extension of the life brings the other Advantageous that costly downtime, consuming Missing productions and costly repairs Application of the roller pair according to the invention can be avoided. Furthermore, the inventive roller pair includes the Advantage that the roll surface of the counter roll not only locally by generating the first embossing pattern but all over or almost full surface by the simultaneous generation of the first embossing pattern and the second embossing pattern the corresponding engravings are machined so that in the use of the counter roll inevitably occurring changes the surface material of the counter roll, in particular Changes in elasticity and / or Shore hardness, always occur evenly over the entire surface, what in a corresponding homogenization of quality the embossing, even after long use of the backing roll, and thus ultimately also in the quality defect of the embossed article expresses conspicuously. Therefore, when using the roller pair according to the invention not only the quality of the embossed Tissue article kept constant but also the required Quality control effort, be it directly through Staff saving during the application of the invention Roller pair or by appropriate personnel savings regarding quality control of embossed tissue articles, considerably reduced, so that overall the invention Roller pair compared to the conventional pair of rollers one Particularly economical process management for the production allowed by embossed tissue articles.

In addition, can be in the inventive roller pair provided engraved roller relatively inexpensive, especially if the second engraving, the second additional An embossed pattern is produced, which is such an engraving has a variety of small-scale individual engravings.

In particular, when in the inventive roller pair such a counter roll is provided whose diameter greater than the diameter of the engraved roll, distribute the damage caused by the desired first engraving over a larger circumference, so that accordingly the Service life of such a counter roll with a corresponding enlarged diameter is further extended. Surprised This has shown that then excellent results regarding a prolonged service life and a reduced service life Wear then occur in the inventive roller pair, if in this case a counter roll is used, whose Diameter is preferably 1% to 10% larger than that Diameter of the engraved roller.

Likewise, an improvement in the life of the backing roll is achieved in the roller pair according to the invention then, when the Anpreßfläche the second engraving at least 60%, preferably between 65% and 85% contacting the counter roll Total contact area. Hereby remains for the desired and especially large-scale first engraving a contact surface of 40%, preferably between 35% and 15 %, based on the total pressure surface, wherein such a coined Tissue article in its overall appearance significantly influenced by the first, desired and preferably large-scale embossing pattern, generated by the first engraving, is determined.

The desired statement of the first, from the first engraving generated embossing pattern and thus its distinctive lifting is in a further advantageous embodiment of the roller pair according to the invention achieved in that second, from the second engraving generated embossing pattern on the Surface of the tissue article generates such a pattern is characterized by a variety of small-scale embossing points is trained. Here, this pattern can be configured arbitrarily be, for example, especially as a wavy line, as a zig-zag line, as a separately arranged rectangles, preferably Four- to octagons, as a multitude of rectangles, in a particular rapport with distance from each other are present or which interlock, and / or as others geometric pattern and / or fantasy pattern, if these patterns are suitable, the one described above ensure uniform wear of the surface of the backing roll.

As already stated above, this variety from small-scale embossed dots on the surface of the formative tissue article are arranged arbitrarily, wherein in a preferred embodiment of the roller pair according to the invention the multitude of single engravings across the surface of the engraved roller extending rows of Single engraving is arranged. Here are in addition arranged adjacent rows relative to each other, so that it is ensured that in the transport direction of the web seen no directly adjacent individual engravings of adjacent rows are aligned, i. on a single line lie, which extends perpendicular to the roll axis.

It is particularly advantageous in the development described above of the roller pair according to the invention, if this the variety of small-scale individual engravings, the second Engraving, on the surface of the engraved roller in such a way is arranged that in the direction of rotation of the engraved Roller saw the location of a single engraving only after a distance between 0.5 cm and 80 cm, preferably after a distance between 5 cm and 50 cm, repeated. Here is under the term location of a single engraving the distance of this single engraving from the roll edge, so that the previously reproduced Statement states that only after a distance of 0.5 cm to 80 cm, preferably after a distance between 5 cm and 50 cm, each seen in the direction of rotation of the roller a second single engraving, measured at a first single engraving Single engraving at the same distance from the roll edge located. All other single engravings between the first and the further single engraving on the surface of the engraved Roller are provided, each have a different Distance to the roll edge, as follows will be explained in detail with reference to the drawings.

Regarding the design of the individual engravings, the second Engraving on the engraved roller are preferred provided such engravings whose contact surface circular, triangular, rectangular, especially quadrangular to octagonal, oval, linear, wavy and / or trapezoidal are designed. Of course, are also different shaped Anpreßflächen possible, provided it is ensured that the sum of these pressure surfaces, which form the second engraving, at least 40% of the total pressure area, i. the sum from the pressure surface of the first engraving and the second engraving, but preferably at least 60% and especially between 65% and 85%, the total pressure area.

With regard to the individual engravings described above is furthermore note that this is preferably a radially after have outside facing height, which depends on the respective varying tissue article between 0.1 mm and 2.5 mm.

In order to avoid a marked, unwanted lifting of the impression caused by the second engraving on the tissue article in the roller pair according to the invention, provides a further advantageous embodiment of the roller pair according to the invention that each individual engraving has a relatively small pressure surface, preferably between 0.1 mm ² and 50 mm ² , in particular between 0.3 mm ² and 10 mm ² , varies. The second embossing pattern produced by each individual engraving then optically recedes as compared to the desired, preferably large, first embossing pattern, but ensures that the counter roll will be uniformly worn over its entire surface.

A further embodiment of the roller pair according to the invention provides that on the surface of the engraved roller provided in the second engraving individual engravings in a density between 5 and 90, based on 1 cm ^{2 of} the roll surface in the second engraving, are available. In this case, the individual engravings are provided in a density between 5 and 30 on 1 cm ² roll surface, these individual engravings are provided with relatively large pressure surfaces, so as to ensure the desired wear of the roll surface of the backing roll, while at a density between 60 and 90, based 1 cm ² of the roll surface, the pressure surface of each individual engraving is preferably made relatively small.

In particular, the roller pair according to the invention has an engraved Roll on, which has a diameter between 300 mm and 1,000 mm.

The pair of rollers according to the invention has an engraved roller Metal roller, in particular a steel roller, a hard rubber roller or a plastic roller, while the counter-roller in particular a rubber roller or a plastic roller made of soft plastic is. Here, the Shore hardness, i. the Shore hardness A, the counter roll preferably between 35 ° Sh and 85 ° Sh.

The present invention further relates to a method for embossing a web-shaped tissue article.

The inventive method for embossing a web-shaped Tissue article uses at least one roller pair, each from a desired first embossing pattern and a second embossing pattern producing engraved roll and a ungravierten counter roll is formed, wherein the to be embossed Tissue article through the nip of at least one Roller pair is guided. This is a pair of rollers used, as this previously as inventive roller pair is described.

Basically, the method according to the invention can be in the simplest Apply case to those tissue articles that are out be formed a single web. advantageously, However, the method of the invention in such Tissue articles applied where these tissue articles are made at least two web are formed, these two Webs optionally simultaneously with a single pair of rollers or separately, each with a pair of rollers be coined per web.

A particularly suitable development of the previously described Embodiments of the method according to the invention provide that in this case each web for itself to create the first Embossed pattern and the second embossing pattern is coined wherein after the separate embossing the two webs then glued together. This will then trained such a tissue article, the relevant Embossing, consisting of the first, desired embossing pattern and the second embossing pattern, both on the top and the underside of the tissue article.

Should according to the inventive method a particular made of voluminous tissue products, so will one Further development of the method according to the invention applied. In this case, each web is then coined separately, where then after the separate embossing of each web the two webs are glued together in such a way that the tissue article respectively on its two surfaces the embossing pattern (first desired embossing pattern and second embossing pattern), wherein the bonding point-like is performed. The for bonding the two webs Required adhesive dots are projecting inwards Increases in the embossing patterns of the upper and lower webs applied, so that only these inward-pointing elevations dot-shaped are glued together, resulting in the so-produced Tissue articles to increase the thickness and thus leading to an increase in volume. Such a voluminous Tissue article possesses besides a pleasant soft Handle a high absorbency and a high absorption capacity for liquids.

Particularly long service life of the rollers are in the inventive Procedure then warrants if as engraved Roll a metal roll, in particular a steel roll, a Hard rubber roller or a plastic roller is used.

Contour-sharp embossing patterns can be especially then achieve by using the method according to the invention, if in the inventive method as counter-roll a Rubber roller or plastic roller is used, wherein the counter-roller by application of the method according to the invention localized line or area damage and wear is protected, as in the beginning of the invention Roller pair is explained, so that the inventive Method used counter roll over its entire Surface is always evenly worn.

In the method according to the invention, the engraved roll driven while the backing roll on the engraved roll pressed and transported thereby, so that the counter-roller even has no own drive but only is moved as idler roller.

The term web is used in the context of the present Invention a cellulosic web, in particular a paper web, understood, usually a limited Length between about 100 m and 100,000 m and a defined Width has, with the width between about 0.3 meters and varies about eight meters.

Figur 1

eine Teildraufsicht auf die Oberfläche einer bekannten gravierten Walze;

Figur 2

eine schematische Teilschnittansicht durch ein Walzenpaar des Standes der Technik;

Figur 2 a

eine Abbildung wie Figur 2, jedoch der oberen Walze;

Figur 3

Draufsichten und Schnittansichten von verschieden gestalteten Einzelgravuren, wie sie als zweite Gravur bei dem erfindungsgemäßen Walzenpaar vorgesehen sind;

Figur 4

eine Teildraufsicht auf die Oberfläche einer ersten Ausführungsform einer gravierten Walze;

Figur 5

eine schematische perspektivische Teilansicht einer Vielzahl von auf der Oberfläche einer gravierten Walze vorgesehenen Einzelgravuren;

Figur 6

eine Teildraufsicht einer zweiten Ausführungsform einer gravierten Walze;

Figur 7

eine Teildraufsicht einer dritten Ausführungsform einer gravierten Walze; und

Figur 8

eine Teildraufsicht einer vierten Ausführungsform einer gravierten Walze.

The invention will be explained in more detail below with reference to embodiments in conjunction with the drawing, in which Figures 1, 2 and 2a represent the prior art and with reference to Figures 3 to 8, the invention described above is explained. Hereby show:

FIG. 1

a partial plan view of the surface of a known engraved roller;

FIG. 2

a schematic partial sectional view through a pair of rollers of the prior art;

Figure 2 a

an illustration as Figure 2, but the upper roller;

FIG. 3

Top views and sectional views of differently shaped individual engravings, as provided as a second engraving in the roller pair according to the invention;

FIG. 4

a partial plan view of the surface of a first embodiment of an engraved roller;

FIG. 5

a schematic perspective partial view of a plurality of provided on the surface of an engraved roller engraved single;

FIG. 6

a partial plan view of a second embodiment of an engraved roller;

FIG. 7

a partial plan view of a third embodiment of an engraved roller; and

FIG. 8

a partial plan view of a fourth embodiment of an engraved roller.

The prior art is used to produce one with a first Embossed pattern provided an engraved tissue article Roller used as its surface partially in plan view is shown in Figure 1. This shows the surface the engraved roller a total of 1 and la designated large-scale floral first engraving on, looking for a predetermined desired pattern over the surface of the engraved Steel roller extends. The first engraving is 1 or la formed from a plurality of individual engravings 2, wherein the Individual engravings 2 radially over the shell of the engraved roll protrude.

As best seen in the partial sectional view of Figure 2 is the well-known used for embossing tissue articles Roller pair a lower engraved roller 3, whose surface is partially shown in Figure 1. This engraved bottom roller 3 made of steel is provided with a drive.

A counter roller 4 is for embossing the tissue article below Forming a nip 5 on the engraved lower Roll 3 pressed and driven by this contact. By The nip 5 becomes a web of a tissue article led here by the engraving 1 or la on this web made of paper then generates a desired first embossing pattern becomes.

Due to the fact that during the embossing process constantly a local pressurization of the counter roll 4 by the engraving. 1 or la takes place on the surface of the counter roll 4 forms already after a relatively short operation in the counter-roller locally limited wear 6, which when reaching a certain depth to a partial localized Damage to the counter roll, which is usually a rubber roller or a roller made of soft plastic leads. Due to this It is required in the prior art, this counter-roller through an undamaged and partially unused counter roll already after a relatively short operating time.

In contrast to the partial plan view depicted in FIG the surface of a known engraved roll have the in Figures 4, 6, 7 and 8 reproduced partial plan views of Surfaces of the engraved rolls according to the invention first, relatively large-scale floral engraving 1 or 1a and in addition still a second engraving 7, wherein the second engraving 7 formed from a plurality of individual engravings 7 a becomes.

A possible selection of such individual engravings 7a to 7g, how they jointly form the second engraving is in the figure 3 shown.

Thus, the single engraving 7 a shown in FIG. 3 consists of a frustoconical single engraving, wherein the circular Anpreßfläche 8 of the individual engraving 7a radially over the engraved Roller protrudes outward and during embossing with the Contact roller comes into contact.

The individual engraving 7 b has an oval shaped contact surface on, the individual engraving 7 c a quadrangular contact surface. 8 c, the hexagonal shaped single engraving 7 d has a hexagonal shaped pressure surface 8 d, the cross-shaped configured Single engraving 7 e has a cross-shaped Anpreßfläche 8 e, the square single engraving 7 f has a square pressure surface 8 f and the S-shaped bent Single engraving 7 g includes a corresponding S-shaped Contact surface 8 g.

Here, a plurality of those shown in Figure 3 by way of example Single engravings 7 a to 7 g to form the second Engraving on the roll surface on the engraved roll, this second engraving 7 ensures that when Embossing the tissue article no localized wear, caused by the first desired engraving 1 or la, occur as in the prior art in conjunction with of Figure 2 is described above. Rather, effect These individual engravings of the second engraving 7, that in the inventive Roller pair or process also the areas 9 (Figure 2) of the counter roll are worn evenly, wherein these located between two adjacent Abnutzungen 6 Areas 9 are not damaged in the conventional method. This then causes the surface of the counter roll not, as in the known method, locally worn out but is evenly removed over its entire surface.

FIG. 5 shows a possible arrangement of the second engraving training individual engravings. Here are these individual engravings 7 in a variety of rows 10 to 19 on the Surface of the engraved roller arranged, the direction of the arrow 20 indicates the transport direction during embossing. In order to simplify the illustration of FIG. 5 accordingly, Here, the curvature of the engraved roll was not considered.

Each engraving has a circular pressure surface 7 a on.

As can be easily seen in FIG. 5, the individual engravings are 7 offset from adjacent rows relative to each other arranged so that in the embodiment shown, the Location of the first single engraving of the series 10 only in the position of first single engraving of the series 15 repeated, while all remaining first individual engravings series 11 to 14 offset this are arranged. This embodiment then causes in particular that the areas 9 (Figure 2) over the entire surface and in desired be reproducibly worn.

Figures 4, 6, 7 and 8 are exemplary different arrangements the second engraving, the surface of a each engraved roller always a first engraving 1 and la and has a second engraving 7.

In the illustrated in Figure 4 surface of the engraved Roller is the second engraving 7 as a variety of oblique too arranged the marked with an arrow direction and aligned parallel rows of individual engravings 7a.

In the illustrated in Figure 6 surface of the engraved Roller is the second engraving 7 through a variety of wavy formed parallel lines, the direction These wavy lines at an angle to that marked with an arrow Running direction of the roller runs.

In the illustrated in Figure 7 surface of the engraved Roller is the second engraving 7 by a variety of pairs arranged quadrilaterals, wherein a larger Square 21 each of four smaller quadrilaterals 22a, 22b, 22c and 22d is symmetrically surrounded. Overall, these are many of quadrilateral oblique to that marked with an arrow Positioning direction of the roller positioned.

In the surface of the engraved surface shown in FIG Roller will be the second engraving 7 through a variety of zigzag lines formed, which are each arranged in parallel and oblique to the direction indicated by an arrow are aligned.

In all the roll surfaces described above, the desired, relatively large first engraving 1 or la also created from a variety of individual engravings, taking a selection of these individual engravings by way of example in FIG. 3 is shown.

Claims (17)

1. A pair of rollers for embossing a web of endless tissue article with an engraved roller and a counter-roller forming a gap therewith, whereby the engraved roller, apart from the desired first engraving, also has a second engraving having a large number of individual engravings with in each case a small-area pressing surface and the first engraving produces a first embossing pattern and the second engraving produces a second embossing pattern, characterised in that the counter-roller has a diameter which is 0,1% to 30% larger or smaller than the diameter of the engraved roller, that the pressing surface (8, 8b - 8g) of the second engraving (7) forms at least 40% of the whole pressing surface coming into contact with the counter-roller and that the individual engravings (7a - 7g) have a height pointing radially outwards that corresponds to the height of the first engraving pointing radially outwards.
2. The pair of rollers according to claim 1, characterised in that the counter-roller has a diameter which is 1% to 10% larger than the diameter of the engraved roller.
3. The pair of rollers according to claim 1 or 2, characterised in that the pressing surface (8, 8a - 8g) of the second engraving (7) forms at least 60%, preferably between 65% and 85%, of the whole pressing surface coming into contact with the counter-roller.
4. The pair of rollers according to any one of the preceding claims, characterised in that the large number of individual engravings (7a - 7g) is arranged in lines (10 - 19) of individual engravings (7a) extending crosswise over the surface of the engraved roller, whereby neighbouring lines (10 - 19) of individual engravings (7a) are arranged offset relative to one another.
5. The pair of rollers according to any one of the preceding claims, characterised in that the large number of individual engravings (7a) is arranged on the surface of the engraved roller in such a way that, viewed in the direction of rotation of the engraved roller, the position of an individual engraving is repeated only after a distance between 0,5 cm and 80 cm, preferably after a distance between 5 cm and 50 cm.
6. The pair of rollers according to any one of the preceding claims, characterised in that the engraved roller has as individual engravings (7a - 7g) engravings which are such that their pressing surface is formed circular, triangular, rectangular, oval and/or trapezoidal.
7. The pair of rollers according to any one of the preceding claims, characterised in that the height of the individual engraving pointing radially outwards varies between 0,1 mm and 2,5 mm.
8. The pair of rollers according to any one of the preceding claims, characterised in that each individual engraving (7a - 7g) has a pressing surface (8, 8b - 8c) between 0,1 mm² and 50 mm², preferably between 0,3 mm² to 10 mm².
9. The pair of rollers according to any one of the preceding claims, characterised in that, on the surface of the engraved roller, the individual engravings (7a - 7g) provided in the region of the second engraving (7) are present in a density between 5 and 90, related to 1 cm² of the roller surface in the region of the second engraving (7).
10. The pair of rollers according to any one of the preceding claims, characterised in that the engraved roller has a diameter between 300 mm and 1000 mm.
11. The pair of rollers according to any one of the preceding claims, characterised in that the engraved roller is a metal roller, in particular a steel roller, a hard-rubber roller or a plastic roller.
12. The pair of rollers according to any one of the preceding claims, characterised in that the counter-roller is a rubber roller or plastic roller.
13. The pair of rollers according to claim 12, characterised in that the Shore A hardness of the counter-roller varies between 35° Shore and 85° Shore.
14. A method for embossing a web of endless tissue article with at least one pair of rollers, which is formed by an engraved roller producing a desired first engraving pattern and a second engraving pattern, and a non-engraved counter-roller, whereby the tissue article to be embossed is guided through the roller gap of the at least one pair of rollers, characterised in that a pair of rollers according to any one of claims 1 to 13 is used.
15. The method according to claim 14, characterised in that the tissue article is formed from at least two fabric webs.
16. The method according to claim 14 or 15, characterised in that each fabric web is embossed by itself and that the two fabric webs are glued together after the embossing.
17. The method according to claim 16, characterised in that the fabric webs are glued together in such a way that each external surface has the embossed patterns and that the gluing is carried out point-wise in such a way, that raised portions of the embossing patterns projecting inwards are jointed together by the point-wise gluing thereby forming a voluminous tissue article.

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