SK286354B6 - Device for the production of a product made from tissue and/or like material with at least two plies - Google Patents

Abstract

A device for manufacturing products, which consist of at least two layers and are made from tissue and/or tissue-like materials, which have adequate adhesion between the individual layers, comprising an embossing unit with at least two rollers, one roller being a plain roller (2) and the other an embossing roller (3). Said embossing roller (3) comprises a shaft (4) and at least two segments (6) arranged thereon with embossing elements (5), wherein the embossing roller (3) is subjected to pressure by means of a bearing unit (7) arranged on the shaft (4).

Description

Technical field

The present invention relates to an apparatus for producing at least two-layer products made of tissue and / or the like by means of a punching unit, as well as a method for producing such products.

BACKGROUND OF THE INVENTION

Tissue and / or similar material find a variety of uses. Such materials include, for example, toilet paper, handkerchiefs, kitchen paper rolls, napkins, paper tablecloths, absorbent and absorbent pads, paper handkerchiefs, dish towels, rags and many other various products.

For the purposes of the present invention, tissue is a product which complies with DIN 6730. Accordingly, tissue is a product which consists wholly or predominantly of pulp fibers, with fine and soft creping and closed formation, produced on a paper machine with a dry matter content of more than 90 %, consisting of one or more layers, which is in particular absorbent, with a specific weight per layer <25 g / cm ² before creping and a creep wet elongation> 5%.

For the purposes of the present invention, a tissue-like material is one which, unlike a tissue material, is produced by changing the drying process. According to the present invention, according to DIN 6730, a similar material to tissue is a product made predominantly of pulp fibers with large and soft creping and open formation, which is dry creped on a paper machine and consists of one or more layers, the density of the individual layer prior to creping < 25 g / cm &lt; ² &gt; and crepe moisture of one layer after crepe &gt; 25%. The material can also be made of old paper.

Products made of tissue and / or similar material are subject to different requirements. In addition to properties such as strength, volume, stiffness and absorbency, one of the most important properties of multilayer products is in particular the adhesion of the layers to one another, in particular the prevention of relative displacement of the layers. In addition, consumers also require good optical properties and, in particular, a decorative appearance from such products.

Various known embossing techniques are used in the prior art to achieve sufficient layer shear resistance in multilayer products. With the so-called steel-rubber shifting, resp. In a steel-paper stamping, one steel cylinder equipped with embossing points (die or embossing cylinder) is pressed against an elastic plain cylinder which is made of rubber or is a steel cylinder coated with a paper layer. This achieves a surface embossing with a small number of embossing points (about 6 to 20 embossing points / cm ² ) or a large number of embossing points (about 25 to 65 embossing points / cm ² ), called micro-embossing, especially full-surface embossing. In this case, the embossing roller is driven, while the elastic counterpart rotates with it as a result of their mutual contact. The action of the embossing points on the tissue material results in both elastic and plastic formation. By plastic molding, at least two embossed layers of material cross each other, at least in part. In this way, at least two layers of the product to be produced are prevented from moving relative to one another. However, the functional adhesion of the layers is not achieved.

In order to achieve the desired adhesion of the layers, the process is additionally followed by a process of additional creasing of the embossed tissue layers. In this case, additionally embossed structures on the overpriced tissue material in the form of continuous patterns (e.g. lines or points) in the direction of movement are achieved by the individually arranged scoring discs which work against the driven smooth roller. The scoring roller is rotated by the friction drive. As a result, an already overpriced tissue product is applied at a pressure of approximately 500 N / mm ² . The disadvantage of using additional creasing is that it can only achieve continuous and uninterrupted patterns on already overpriced patterns and, moreover, reduces the softness of the tissue product in the area of the applied creasing structure. A further disadvantage with the use of the creasing machine is that it can be realized exclusively with uninterrupted embossed grooves in the direction of movement of the tissue web. They cannot achieve embossing with a decorative look.

In addition, the problem, especially in the case of toilet paper, is the so-called defective perforation. This is the case, for example, in the case of a roll of multi-layer toilet paper, inadvertently wrapping a separate, not sufficiently cohesive tissue layer with a roll of toilet paper. The perforation lines between two separate sheets of toilet paper do not lie one above the other. This occurs particularly often at the beginning of the roll of toilet paper when the first sheet is torn off and is glued to the layer of toilet paper lying underneath. This problem of erroneous perforation occurs in all known embossing methods where the cohesiveness of the layers is not achieved.

Another known method of embossing is the so-called union embossing method. In this union, the at least two-layer starting material is guided between at least two mutually opposed rollers, the rollers having radially arranged projections on their surfaces, the cross-section of which is in the form of a blunt pyramid. The protrusions of one cylinder engage in recesses formed by the protrusions of the other cylinder. The starting material passes between the two rollers, and is embossed over the projections of the two rollers over the entire surface or on a part of the surface. Since the punching points formed and the flutes which lie against these grooves cannot come into contact with the unwinding movement of the two rollers, the starting material is pushed against each other during the union embossing. By this punching, at least two of the starting sheets cross each other, but still this does not achieve sufficient layer shifting to prevent erratic perforation. For this reason, the gap between the rollers must be adjusted very precisely for both rollers, otherwise the two opposing rollers could be damaged. In general, tissue products produced by the union embossing process are additionally scored by the scoring process.

Multilayer tissues are also produced by the so-called spot-smoothing process. In this case, the steel cylinder provided with the embossing points and the smooth steel cylinder (the so-called smooth cylinder) are arranged such that a defined distance is maintained between them. This distance is achieved by an expensive slot adjustment. The starting strips of material are pressed together so strongly that the layers are mutually fixed as they pass between the smooth roller and the embossing roller. The pressure required for this compression must be exerted by the cylindrical structure itself. The required pressures are in the range of about 230 N / m ² . Due to this high pressure, the method is limited to narrow widths of the material web, e.g. In this case, a support related to the embossing roller / counter-roller system is required. By this system, embossed patterns can be applied in the form of longitudinal or transverse lines, which are known, for example, in handkerchiefs. The absence of support of the embossing roller against the smooth roller may result in a "puncture" or "lifting" of the embossing roller. In the first case, this leads to damage to the embossing cylinder ("flattening embossing points") by touching the embossing points with the smooth cylinder. In the latter case, the coherence of the layers is not obtained (insufficient compression of the tissue layers). Compensation between the application of the longitudinal and transverse lines (especially for handkerchiefs) is difficult to achieve by adjusting between the embossing and smooth rollers.

In addition, various methods are known in the art in which, in addition to embossing in which differently distributed patterns are applied to the surface, partial or full-surface gluing is followed. For this purpose, it is necessary to use an adhesive device in series, which, however, increases production costs. The adhesive device applies the adhesive to the tissue layers via the adhesive rollers. A portion of the adhesive is applied to the tissue layer, and a portion is collected for reuse in the container. However, the adhesive is contaminated by the high dust content of the tissue belt. The adhesive unit therefore has high cleaning costs. Finally, due to the application of the adhesive, although it is applied only partially and not over the entire surface to the tissue strips, the resulting tissue product is "plate-like", that is, clearly loses its softness. A further disadvantage is that the use of the adhesive is limited to a maximum of 3-layer tissue products, since the applied adhesive must penetrate the individual layers for bonding.

The so-called decorative print, i.e. j. forming punches by which shaped patterns such as flowers and the like can be applied. on the tissue product, is achieved, for example, by an additional embossing unit / adhesive unit. On the embossing roller, for example, some embossing points are formed in the region of the desired decorative print, in the form of the desired shape pattern. However, such an additional embossing does not achieve any additional adhesion of the layers, which is less compared to full-surface micro-embossed products, so that gluing with these drawbacks and / or creasing with a scoring machine is necessary. However, the additional creasing deteriorates the good optical appearance, especially when the creasing takes place through the shape patterns shown.

It is therefore an object of the present invention to provide a device that does not have the drawbacks of devices known in the art.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved by an apparatus for producing at least two-layer tissue and / or similar material products comprising an embossing unit with at least two rollers, one of which is a smooth roller and the other is a embossing roller. it comprises a shaft and at least one bearing unit arranged thereon, the cylinder being subjected to pressure by at least one bearing unit arranged on the shaft and wherein the bearing unit is arranged between two segments. The pressure is transmitted to the bearing unit by a pressure device. The pressure device may act on the bearing unit between the two segments immediately through the extension. By means of the device according to the invention it is possible to produce multilayer products having excellent layer cohesion. In addition, the cohesiveness of the layers can be achieved at a conventional machine width of, for example, 2800 mm or more.

Thus, in the case of non-pretended tissue, the fishing unit or the adhesive unit necessary to ensure the bonding of the layers is omitted and the decorative print is applied. The device according to the invention replaces the creasing unit or the gluing unit which are required in the above-mentioned methods for producing tissue products.

The device according to the invention makes it possible to emboss the web of the starting material in whole or in part. It is particularly advantageous here to apply the decorative print by means of punching elements. There is also no need for glue application.

The high pressure required for the pressure action is preferably obtained from at least one pressure device comprising at least one pressure cylinder. In this case, one pressure device can be associated with each segment, but preferably two segments are associated with one pressure device. The pressure cylinders can be activated or deactivated. However, it is also possible to activate several pressure cylinders together. The pressure devices are preferably movable independently of one another. For example, at a tissue width of approximately 2800 mm, 27 pressure cylinders and a corresponding number of 28 segments can be arranged on the shaft. The shaft together with the bearing device and the segments form an embossing cylinder. By means of a targeted compressive action on the individual segments by means of the bearing unit, the rolls are prevented from bending relative to one another, and the flexible punching roller also adapts to the flexible smooth roller. The advantage of this is that the rollers are not mutually damaged. Compressing through the segments containing the embossing elements provides a uniform and defined support for the entire embossing roll. The pressure cylinder of the pressure device may be adjusted to a pressure in the range of from about 3 to 10 bar, particularly preferably from 4 to 6 bar.

According to a further embodiment of the invention, the pressure device is provided with a stop for adjusting the gap between the rollers. Preferably, this stop is adjustable by means of a wedge. Thereby it is possible to bias the embossing roll in a targeted manner before being used by separate pressure devices.

The bearing unit preferably comprises ball bearings. However, it is possible to use a bearing of any other known type. Importantly, this bearing is intended to withstand radial loads and also have axial guiding properties. In addition, the bearings can also be equipped with a guide. By acting of the pressure cylinder through the bearing device on the embossing cylinder, on the one hand, the slot can be precisely adjusted externally even during machine operation, and on the other hand, any possible oscillations of the embossing cylinder are absorbed by the bearing unit. A further intermediate bearing may be provided between the pressure cylinder and the bearing unit.

The embossing roller is preferably provided with a quick-release device. This makes it possible in a relatively simple way to create different patterns according to the customer's wishes (especially logos) in a single workflow. Preferably, the embossing roller is provided with a quick-release device mounted on a separate journal.

Both the smooth roller and the embossing roller of the device according to the invention can have the same diameter. However, this is not necessary, but rollers of different diameters can also be used. Preferably, both the smooth roller and the embossing roller have the same circulation speed. In addition, both the smooth roller and the embossing roller can be driven in an advantageous manner.

By means of the device according to the invention, in contrast to the creasing methods, decorative prints can be applied not only continuously and continuously, but also insulated and individual.

The present invention further relates to a method for producing at least two-layer tissue and / or similar material articles on an apparatus according to the invention, wherein:

- in a first step, at least two material strips are fed into the gap between the smooth roller and the embossing roller, the embossing roller being subjected to pressure;

- in a second step, the material strips are joined together by segments provided with punching elements; and

- in a third step, the product obtained is taken from the apparatus.

The process according to the invention advantageously produces products which have excellent layer adhesion properties. It is also possible to produce products with very nice decorative prints. According to a preferred embodiment of the method according to the invention, the bonding of the individual material strips is carried out with a pressure of at least 700 N / mm ² . Preferably pressures of at least 900 N / mm ² , and more preferably at least 1100 N / mm ^{2, are used} . Such pressures on the material strips can only be achieved in such a way that the embossing cylinder is adapted to be pressurized by the bearing on the individual segments.

On the device according to the invention, it is possible to produce at least a two-layer product of tissue and / or similar material. Advantageously, such at least two-layer product provided with a decorative print on the outside no longer contains any further embossing, in particular a micro-embossing. It is further preferred that it is not knurled and / or glued. The at least two-layer material according to the invention therefore has excellent optical and contact properties, and moreover the two layers are very cohesive to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the present invention will be elucidated in the following on the basis of exemplary embodiments and the accompanying drawings. In the drawings: FIG. 1 is a cross-sectional view of an embossing unit of a device according to the invention;

Fig. 2 is a side view of an embossing roll according to the invention; Fig. 3 is a top view of a cut-out of a segment with a punch element.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows the embossing unit of a device for producing at least two-layer tissue and / or similar material products according to the invention by 1. The embossing unit 1 comprises a smooth roller 2 as well as an embossing roller 3. The smooth roller 2 and the embossing roller 3 rotate with respect to each other and are driven in the direction of the arrow 17 and 18. The smooth roller 2 has a slightly larger diameter than the embossing roller 3.

The embossing roll 3 comprises a shaft 4, and is mounted on its bearing unit 7. Further, the embossing roll 3 comprises embossing beers 5. The embossing roll 3 is supported by an extension 22 of the pressure device 8. This attachment 22 is arranged on a rocking lever 21 which side stop 10 and pressure cylinder 9.

In this case, the pressure cylinder 9 exerts pressure in the direction of the arrow 30 via the rocker lever 21 and the extension 22 on the embossing cylinder 3. In this case, the embossing cylinder 3 is biased against the smooth cylinder 2 by means of the stop 10. a defined slot 11 is set. The stop 10 can be realized, for example, by a wedge stop not shown here, the wedge being movable by means of a slotted nut and acting at the end of the rocker 21 associated with the rocker 10. However, the stop 10 can also act directly on the pressure device 8 by means of a screw without the aid of a wedge at the end of the rocking lever 21. The pressure cylinder 9 is filled through a pressure supply (not shown) to a pressure of approximately 5 bar.

To produce, for example, a bilayer tissue product, the material webs 14 and 15 of unstretched, monolayer material in the direction of the arrows 19 and 20 are fed together to the embossing unit 1. They are guided through a slot 11 between the smooth roller 2 and embossing roller 3. 15, the embossing elements 5 disposed on the embossing roll 3 are provided with a decorative print and at the same time they are joined. The thus joined two-layer product 16 is further removed and taken from the punching unit 1.

The smooth roller 2 and the embossing roller 3 are driven by a fixed gear drive, which may be a pair of rapporträder. This achieves that the smooth roller 2 and the embossing roller 3 have the same orbital speed.

In FIG. 2 the arrangement of the embossing roll 3 is shown. The embossing roll 3 consists of segments 6 which are arranged on the embossing unit shaft 4 with the overall width of the material web. Thus, for example, for a single strip width of 2800 mm, 28 segments 6 are arranged together. These segments 6 carry punching elements 5 which are arranged side by side and mounted on segments 6. The punching elements 5 on the segments 6 are arranged, for example, on a toilet sheet. The paper has 5 elements with decorative print. This is sufficient to permanently bond the layers. However, several decorative embossing elements per sheet may also be provided.

Bearing units 7 are arranged between the individual segments 6, in which the extension 22 of the pressure device 8 fits. The bearing unit 7 consists of a bushing 24 which is fixedly connected to the shaft 4. A bushing 25, which includes a ball bearing 12, is mounted. Guiding the bearing 12 is provided by the cover 25. Furthermore, the bearing 12 is arranged against the longitudinal axis of the shaft 4 so that it can absorb axial forces exerted on the bearing 12 by the pressure device 8.

The individual segments 6 of the embossing cylinder 3 are interconnected by means of pins 23. These are housed in mutually coaxial recesses of pairs of adjacent segments 6. The segments 6, the housing 24 and the cover 25 are guided radially on the shaft 4. Axial fixation of the segments 6 is achieved by means of pins 23 arranged externally on the housing 24, by clamping all the segments 6 with the housing 24 and the cover 25 by means of at least one nut 31 arranged externally and laterally on the shaft. The nut 31 acts on the corresponding segments 6 via a connecting element 32 having at least on one side a recess for receiving the pin 23 coaxially arranged to receive the first segment 6.1 to radially fix the segments 6 by means of a pin 23 located laterally on the housing 24 In this way, the segments 6 can be rotated relative to adjacent segments, thereby achieving a uniform load distribution during operation. In addition, it will be preferable to use only one type of segments per cylinder.

The embossing roller 3 is provided with a quick-release device 13. This consists of a dome element 26 which is fastened to the bolts of the device according to the invention by means of hexagonal screws 28 and 29. The driving of the embossing roll 3 is made possible by a tight tongue (not shown) fixed on the shaft 4 contained in the cupola element 26 and allows easy fixing by a threaded screw 27. By using a quick-clamping device 13 it is possible for the embossing roll 3 to be easily and quickly remove from the machine tool and replace it with another cylinder which is provided with embossing elements 5 with different patterns. Thus it is possible to apply different ornamental prints with one machine.

The individual embossing elements 5 are mounted on the segments 6 of the embossing cylinder 3 and have a circular construction. However, any other form may also be used, for example the embossing elements 5 may have a square, rectangular or pyramidal shape. By placing the embossing elements 5 side by side on the segments 6, a uniform load distribution over the entire width of the embossing roll 3 is preferably achieved.

Fig. 3 shows the embossing element 5 itself, which is located on the embossing segment 6 of the embossing roller 3. The embossing element 5 is circular in shape and comprises a base 31 on which the embossing points 32 are arranged such that they form a letter &quot; M &quot; Of course, other letters, characters, or pictorial representations such as flowers or the like are also possible. The depth distance of the embossing points 32 from the base 31 is adjusted according to the shaped elements 33 and the embossed material. The depth spacing of the base 31 from the segmented base 34 is selected so as to prevent crushing of the tissue web.

The punching unit 1 produces a two-layer tissue product. Non-spun tissue material having a grammage in the range of about 18.5 to 22 g / cm ² and a thickness of about 150 µm can be used as the starting material. An ornamental embossing in the shape of FIG. 3 of the letter "M". A pressure of 5 bar is applied to the pressure cylinder. The width of the material strips is approximately 2800 mm. The pressing pressure is about 1150 N / mm ² , the linear pressure is about 85 N / mm. The linear pressure is generally at least 45 N / mm and preferably ranges from 60 N / mm to 110 N / mm, even more preferably from 80 N / mm to 100 N / mm. A two-layer tissue product is obtained which, without further creasing or gluing, has well-connected layers to one another. In the area of ornamental printing, no concavities were observed, which occur particularly during creasing, and no densification of the product was observed. If the tissue product produced in this way is held against the light source, it can be clearly observed that in the area of the ornamental printing the product is clearly more translucent than in the non-embossed area. In addition, the aforementioned flat-embossed tissue product (micro-embossing) was obtained by the embossing unit 1. The individual layers (in this case four) are fixed to each other by means of a series of decorative embossments. The appearance of the decorative embossing is equal to the above.

First of all, the device according to the invention makes it possible to achieve a sufficient and high cohesion of ¹ layers between the layers of a multilayer tissue product. Moreover, this cohesiveness of the layers is realized exclusively by decorative embossing. In particular, when using the device according to the invention, it is not necessary to use either creasing or gluing of the product to achieve cohesive layers. The device according to the invention makes it possible for the first time to embellish strips of material with a width of 2800 mm or more. The pressure device used in the device according to the invention makes it possible to ensure continuous and constant support of the segments. The embossing roll is easily and quickly exchangeable so that various decorative patterns can be realized according to customer requirements without great assembly costs by simply replacing the embossing roll.

Claims (10)

PATENT CLAIMS Apparatus for producing at least two-layer products of tissue and / or the like, comprising an embossing unit (1) with at least two rollers, one of which is a smooth roller (2) and the other roller is a embossing roller, the embossing roller (3) comprising a shaft (4) and at least one bearing unit (7) disposed on the shaft (4), characterized in that the embossing roller (3) comprises at least two segments (6) arranged thereon equipped with embossing elements (5) and that embossing roller (3) is subjected to pressure by at least one bearing unit (7) arranged on the shaft (4), the bearing unit (7) being arranged between two segments (6). Device according to claim 1, characterized in that decorative embossing is applied by means of the embossing elements (5). Apparatus according to claim 1 or 2, characterized in that the pressure action is carried out by means of at least one pressure device (8) comprising at least one pressure cylinder (9). Device according to one of the preceding claims, characterized in that the pressure device (8) is provided with a stop (10) for adjusting the gap (11) between the rollers (2, 3). Device according to one of the preceding claims, characterized in that the metal unit (7) comprises a ball bearing (12). Device according to one of the preceding claims, wherein the roller (3) is provided with a quick-release device (13). Device according to one of the preceding claims, characterized in that the roller (2) and the embossing roller (3) have the same circulation speed. Device according to one of the preceding claims, characterized in that the roller (2) and the embossing roller (3) are driven. An embossing roller comprising a shaft (4) and at least one bearing unit (7) arranged on the shaft (4), characterized in that the embossing roller (3) comprises at least two segments (6) arranged thereon equipped with embossing elements (5) and that the cylinder (3) is subjected to pressure by at least one bearing unit (7) arranged on the shaft (4), the bearing unit (7) being arranged between two segments (6). Method for producing at least two-layer tissue and / or similar material products on a device according to claims 1 to 9, wherein in the first step at least two material strips (14, 15) are fed into the slot