EP2682258A1 - Method and apparatus for embossing multilayer tissue webs - Google Patents

Abstract

The method involves passing two layers of a tissue trajectory (100) through a embossing gap (A) formed between embossing roller (1) and a backing roll (2). The raised projections are embossed in tissue trajectory corresponding to the embossing pattern (10). The embossed layers of tissue trajectory are passed through embossing gap (B) formed between embossing roller and backing roll (3). A subsequent stamping of type-point is produced against in region of raised projections, by backing roll (3) constructed with rigid and non-elastic flexible surface and embossing gap (B).

Description

The invention relates to a method for embossing multi-layered tissue webs of a predetermined width, in which at least two layers of the tissue web pass through a first embossing gap between an embossing roller provided at least in regions with a raised embossing pattern and a first counter-roller having an elastically yielding surface and in Direction of the first counter-roller raised projections are embossed in the tissue web according to the embossing pattern and then the thus embossed layers of the tissue web on the embossing roller resting on a second embossing gap between the embossing roller and a second counter-roller.

It is known to interconnect multi-ply tissue webs by embossing between single or double-sided engraved embossing rolls to form the interconnected tissue layers, e.g. to be used for the production of napkins, handkerchiefs or toilet paper. A distinction is made here between surface embossing, in which the entire surface of the tissue webs is embossed, and embossing, in which only partial areas of the tissue webs are embossed, while the remaining subareas are not embossed.

From the US 2010/0006247 A1 It is known to first emboss tissue webs in full form between a profiled embossing roll and a rubberized counter roll and then between the embossing roll and a

Variety of aligned on rolls soft rolls, each covering only a small width portion of the Tisssue-Bahn pass, to improve the embossing result. The known method is thus suitable only for the production of full-surface embossed tissue webs, but not for format embossing of the type mentioned.

When embossing tissue layers between a profiled and a smooth roll, a rough surface usually forms on the surface which rests on the smooth roll, since the embossing tips press on this side. This is undesirable and is remedied by applying another layer of tissue material on this rough side, e.g. by glue. However, the glue fixation of the smooth tissue layer is complicated and causes high costs, which seems to be in need of improvement.

The object of the invention is therefore to propose a method and a device which avoids the disadvantages of the prior art.

To achieve the object, the embodiment of the method according to the features of claim 1 is proposed according to the invention.

Advantageous embodiments and further developments are the subject of the dependent claims.

The invention proposes that the second mating roll is designed to form the second embossing gap with a stiff and elastically non-compliant surface and in the second embossing gap a locally limited re-embossing of the point-to-surface type in the region of the raised projections is effected.

Due to this locally limited stamping exclusively in the area of the raised projections, new applications of the invention result. According to a first proposal of the invention, it is possible by means of the method according to the invention to simulate a typical Union stamping variable. For this purpose, according to the invention, the layers of the tissue web embossed in the first nip are adhesively bonded together by means of the stamping only in the region of the raised projections.

This is due to the fact that initially the layers of the tissue web in the first nip an embossed pattern is formed, which gives the layers a desired volume. The stamping pressure prevailing in the first nip is in this case advantageously adjustable, so that as the stamping pressure increases, the volume produced in the tissue web is correspondingly increased. However, it is characteristic that the individual embossed layers of the tissue web only experience an increase in volume after leaving the first embossing gap in the region of the raised projections formed by the embossing, but not a significant adherent connection with the adjacent layers. However, according to the invention, the layers thus embossed continue to rest on the embossing roll, i. with engagement of the raised embossing pattern of the embossing roll in the raised projections of the tissue web, to supply a second nip in which a "point on area" is done, then the individual layers of the tissue web are in the second nip only in the raised projections, ie corresponding locally limited adherent connected.

The tissue web thus obtained in accordance with the present invention is very similar to a Union embossed web, except that the ply adhesion is effected only on the raised areas of the tissue web. In this way it is possible to make the volume, ie the height of the forming raised projections very variable, without affecting the ply adhesion. The ply adhesion is always effected according to the invention uniformly over the stamping in the second nip. It is irrelevant whether the tissue web is embossed over the entire surface or - as is common, for example, with paper napkins or handkerchiefs - only in the marginal area.

A further possible variant of the method according to the invention provides that after passing through the first embossing gap at least one further layer is placed on the embossed layers of the tissue web and these pass through the second embossing gap together, wherein the at least one further layer by means of the imprint in Area of the raised projections with the embossed layers is firmly bonded. Therefore, this at least one further layer does not have an embossing originating from the first embossing nip and forms a smooth covering layer on the embossed layers of the tissue web and is adhered firmly together with these in the second nip in the region of the raised projections without it the addition of adhesives is needed. This gives a very smooth-surfaced tissue web from both sides, the individual layers of which are bonded to the embossed layers in the region of the raised protrusions in the region of the raised protrusions in the second nip without any adhesive.

This embossment according to the invention has the advantage that the relatively coarsely embossed structure side of a volume embossing by one or more unembossed material layers, which are embossed in a point / surface embossing station with the or the separately embossed layers into a unit, so that a smooth bottom regardless of how high or rough the previously embossed structure is.

According to one proposal of the invention, the multi-ply web, which consists for example of several layers of tissue webs when a smooth side is to be generated, coming from the settlement through a ply separation station and on the number of layers for the lower smooth side and the upper to be embossed Page shared. It is understood that the top and bottom can also be reversed. The thus divided materials, which may be carried out to x-ply, are then fed to the individual embossing stations, if necessary, even web guide elements, such as a side edge control, pulleys, etc., can be integrated.

The one of the divided material webs passes through an additional embossing station and is fed to the embossing nip of the embossing according to the invention in the second embossing nip lying on the positively engraved steel roller following the embossing (volume embossing). The other material web resulting from the division is conveyed via web guiding elements, e.g. Deflection rollers or side edge control also supplied to the second embossing gap of the dot / surface embossing. In this point / surface embossing unit, the two material webs, i. the already embossed single- or multi-ply web and the other still smooth and also single-layer or multi-layered web formed into a composite, i. the individual layers of both web halves, namely the embossed embossing elements projecting upwards in the material, are embossed on the upstanding surface point with the smooth unembossed material to form a unit. This embossing is done as usual under pressure in the point / surface embossing and there is an arrest of the individual layers to each other without the addition of glue.

In order to allow in particular the processing of format embossing, for example edge embossing of napkins or handkerchiefs, according to the invention, the embossing roller and the first and second counter-rollers extend over the entire width of the tissue web. In the region of the axial ends of the individual aforementioned rollers, these are preferably supported on one another via races, as shown in FIG EP 1 080 876 A1 is described in detail and the disclosure content of which is expressly referred to in this context.

According to a further proposal of the invention it is provided that the second embossing gap is arranged downstream of at least one further embossing gap between the embossing roller and a further roller, which is traversed by the resting on the embossing roller tissue web. In this at least one further embossing gap, for example, a localized individual element can be embossed into the tissue web.

The localized individual element of the further roller may, depending on the purpose, have a different or the same engraving height as the embossing roller, the engraving itself may e.g. Engraving elements or lettering include.

The method according to the invention described above can be installed in a simple manner in almost any existing embossing station. Additional embossing rollers, which act against the smooth second counter-roller, are possible and conceivable.

Furthermore, logo or element embossing can be supplemented or made possible.

• Figur 1 in einer schematisierten Darstellung eine erste Ausführungsform der Erfindung.
• Figur 2 in einer schematisierten Darstellung eine zweite Ausführungsform des erfindungsgemäßen Verfahrens.
• Figur 3 in einer schematisierten Darstellung eine dritte Ausführungsform des erfindungsgemäßen Verfahrens.
• Figur 4 einen Schnitt durch eine nach dem erfindungsgemäßen Verfahren hergestellte Tissue-Bahn.
• Figur 5 einen Schnitt durch eine weitere Ausführungsform einer nach dem erfindungsgemäßen Verfahren hergestellten Tissue-Bahn.
• Figur 6 die Aufsicht auf eine nach dem erfindungsgemäßen Verfahren hergestellte Tissue-Bahn.

Further explanations of the invention will become apparent from the accompanying drawings. Show it:

• FIG. 1 in a schematic representation of a first embodiment of the invention.
• FIG. 2 in a schematic representation of a second embodiment of the method according to the invention.
• FIG. 3 in a schematic representation of a third embodiment of the method according to the invention.
• FIG. 4 a section through a tissue web produced by the process according to the invention.
• FIG. 5 a section through a further embodiment of a tissue web produced by the method according to the invention.
• FIG. 6 the supervision of a tissue web produced by the process according to the invention.

From the FIG. 1 there is shown a method of embossing multi-ply tissue webs wherein a tissue web 100 comprising at least two plies is fed to a first nip A which is sandwiched between an embossing roll 1 having a raised embossing pattern 10 and a first counter-roll 2 having an elastically yielding surface is formed. This elastically yielding surface may be formed, for example, by a rubber coating of the roll surface of the counter-roller 2.

According to the raised embossing pattern 10 of the embossing roll 1, the embossed pattern 10 is embossed in the supplied layers of the tissue web 100, as in more detail from the FIG. 4 can be seen, wherein the individual layers of the tissue web are denoted by 100.1 and 100.2.

After leaving the first embossing nip A, the superimposed tissue layers 100.1 and 100.2 have a course which follows the embossing pattern 10 of the embossing roller 1 by embossing raised projections in the direction of the first counter-roller 2 in the tissue web according to the embossing pattern.

Subsequently, the thus embossed layers of the tissue web on the embossing roll 1 are further supplied superimposed to a second embossing gap B, which is formed between the further guiding the tissue web 100 serving embossing roller 1 and another, referred to as second counter roll 3 roller. In this case, the raised structures of the embossing pattern 10 formed on the surface of the embossing roller 1 are furthermore in engagement with the raised projections in the tissue web 100.

It is characteristic of the second embossing gap B that the second counter-roller 3 is designed with a stiff and elastically non-compliant surface, eg a polished steel surface, so that in the second embossing gap an embossing of the already introduced embossing pattern of the point-to-surface type exclusively in the region of raised projections is effected.

In that regard, the tissue web receives no further embossing pattern when passing through the second embossing gap B, but the individual layers 100.1, 100.2 are in the region of the already formed raised projections by a point-surface pressure in the FIG. 4 103 marked area pressed so strong that sets a sufficient adhesive bond between the layers 100.1, 100.2. However, the adherent bond exists only in the area 103, but not in the previously unembossed areas in which the individual tissue layers 100.1, 100.2 still lie loosely on each other.

In that regard, a product of a tissue web is obtained from several layers 100.1, 100.2, which is very suitable, for example, for use as a paper napkin or handkerchief and has been embossed similar to a Unionwalzenprägung, but with the difference that the ply adhesion only on the upstanding surface 103 of the embossing is generated. In this case, the volume of the embossing, that is to say the degree with which the protruding areas 103 project beyond the further or other course of the tissue layers 100.1, 100.2, can be determined variably and simply by varying the pressing pressure in the first nip A accordingly, however, this does not affect ply adhesion. By ensuring a sufficient pressing pressure in the nip B, it is ensured that the individual layers 100.1, 100.2 are adequately interconnected independently of the volume of the embossing.

For this purpose, suitable, not shown, but known from the prior art devices are provided, by means of which the pressing pressure between the embossing roll 1 and the first and second counter-rollers 2, 3 is changed accordingly.

In a comparison with the first embodiment according to FIG. 1 and 4 modified embodiment, which from the FIG. 2 it can be seen, a tissue web is produced, which is characterized by two smooth surfaces with comparable ply adhesion. In a layer connection according to the aforementioned embodiment in FIG FIG. 1 Namely, there is a certain roughness of the surface to accept that the upstanding areas or raised projections 103, while in the embodiment according to FIG. 4 corresponding bottom feels relatively smooth.

To address this problem, the embodiment according to FIG. 2 the supplied multi-layered tissue web 100 is first divided into a layer separating device 5 into a first and second partial web 101 or 102, which may each comprise a plurality of layers of the tissue web, but may also each comprise only a single layer of the tissue web.

The first partial web 101 passes through the first embossing gap A between the embossing roller 1 and the smooth counter-roller 2 provided with an elastically yielding surface as already described with reference to the exemplary embodiment FIG. 1 Described and accordingly receives an embossing pattern with raised projections corresponding to the embossing pattern 10 of the embossing roll. 1

Before the thus embossed first partial web 101 analogous to the embodiment according to FIG. 1 is fed to the second embossing gap B between the embossing roll 1 and the second counter-roll 3 equipped with an elastically non-compliant surface, the previously divided second sub-web 102 is likewise fed to the embossing gap B via the deflection rolls 4, like the first sub-web 101 resting on the embossing roll 1 both partial webs 101, 102 pass through the embossing gap together. Upon entry into the second embossing gap B, however, the first partial web 101 is already embossed, while the second partial web 102 is present unembossed. As a result, within the second embossing nip B, in turn, a dot-surface embossing is performed in the region of the raised projections 103, whereby not only, as already described with reference to FIGS FIG. 4 described, the individual layers 100.1, 100.2 of the first partial web 101 are connected to each other in the region of the raised projections 103, but also the unembossed second partial web 102 is in the region of these raised projections 103 firmly connected to the individual layers 100.1, 100.2 of the first partial web 101. The result is thus a product of a multi-layered tissue web, which is relatively smooth on the top and bottom. The haptic perception is many times better than at a normal embossment with a negative smooth side and a positive rough side, such as out FIG. 4 seen. Such tissue webs have hitherto been produced only with the aid of adhesives or glue, but the method according to the invention makes it possible reliably to produce such a web without the aid of adhesive or glue due to the stamping in the second embossing gap of the point-to-face type.

Particularly preferred embossings of the tissue web according to the invention in embossing gap A for the embossing of so-called formats, as they are from the supervision in accordance with FIG. 6 are apparent and are needed eg for the napkin or tissue production. It can be seen on the basis of the exemplary illustration of a tissue web 100 that embossings 103 are arranged only in the manner of a grid in the edge area of tissue web 100, while large parts of the tissue web are unembossed, that is to say that in this area the individual layers are not embossed connected with each other. Of course, the indicated by arrow feed direction in the illustrated embodiment according to FIG. 6 also be chosen differently and it is also possible to create several such embossing patterns side by side across the width of the tissue web. All of the embossing and counterrolls 1, 2 and 3 shown extend over the entire width of the tissue web 100.

From the embodiment according to FIG. 3 is compared to the embodiment of FIG. 2 Yet another embodiment can be seen in which the second embossing gap B downstream of a third embossing gap C is provided, which is formed between the embossing roller 1 and another counter-roller 6, through which in the embossing gap B interconnected tissue layers according to FIG. 5 be guided.

For example, this embossing roll 6 can have an embossed structure on your part and locally provide the layers of the tissue web which are already connected to one another with a single element which is embossed into the surface, for example that in FIG FIG. 6 stellverstretend shown in a corner area logo 104. It is understood that the embossing roll 1 in this Area in which the embossing roller 6 acts, should have a corresponding compliant surface or a recess.

In addition to the creation of embossing rollers, which operate according to the above-explained method, it is also possible in a simple manner to convert already existing embossing stations in view of the above-described method, for example, if already a pair of embossing rollers to form the embossing gap A or B is present and the Station then only has to be supplemented by the respective missing counter-roller to form the embossing nip B and A respectively.

In order to prevent the embossing or counter-rollers 1, 2, 3, 6 in creating format embossing according to FIG. 6 undergo strong load changes, these have the already mentioned in the foregoing description support by means of races on each other, as is known in the prior art.

Claims (7)

Method for embossing multi-ply tissue webs (100), in which at least two plies (100.1, 100.2) of the tissue web (100) have a first embossing gap (A) between an embossing roll (1) provided at least in regions with a raised embossing pattern (10) ) and a first counter-roller (2) with an elastically yielding surface and in the direction of the first counter-roller (2) raised projections (103) in the tissue web (100) are embossed according to the embossing pattern (10) and then embossed thus embossed Laying (100.1, 100.2) of the tissue web (100) on the embossing roll (1) lying on a second embossing gap (B) between the embossing roller (1) and a second counter-roller (3), characterized in that the second counter-roller (3 ) is executed with a stiff and elastically non-compliant surface and in the second embossing gap (B) a re-embossing of the type point against surface in the region of the raised projections (103) is effected. A method according to claim 1, characterized in that the embossed layers (100.1, 100.2) of the tissue web (100) by means of the stamping in the region of the raised projections (103) are adhesively bonded together. A method according to claim 1 or 2, characterized in that after passing through the first embossing gap (A) at least one further layer on the embossed layers (100.1, 100.2) of the tissue web (100) is placed and collectively the second embossing gap (B ), wherein the at least one further layer is adhesively bonded to the embossed layers (100.1, 100.2) by means of the embossing in the region of the raised projections (103). Method according to one of claims 1 to 3, characterized in that the embossing roller (1) and the first and second counter-rollers (2, 3) extend over the entire width of the tissue web (100). Method according to one of claims 1 to 4, characterized in that the pressing pressure between the embossing roll (1) and the first and second embossing roll (2, 3) is variable. Method according to one of claims 1 to 5, characterized in that the second embossing gap (B) arranged downstream of at least one further embossing gap (C) between the embossing roller (1) and a further roller (6), which of the on the embossing roller ( 1) lying tissue web (100) is passed through. A method according to claim 6, characterized in that in the further embossing gap (C) a locally limited individual element (104) is embossed in the tissue web (100).

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