EP0851951A1

EP0851951A1 - Multilayered web-type tissue product with an unembossed, substantially freely mobile inner layer; the production of the tissue product; and a device for use in its manufacture

Info

Publication number: EP0851951A1
Application number: EP96932581A
Authority: EP
Inventors: Josef Berger; Friedrich Geishofer; Thomas Heilemann; Hermann Klemmer
Original assignee: SCA Hygiene Paper GmbH
Current assignee: Essity Germany GmbH
Priority date: 1995-09-20
Filing date: 1996-09-20
Publication date: 1998-07-08
Anticipated expiration: 2016-09-20
Also published as: NO981236D0; EP0851951B9; EP0851951B1; DK0851951T3; ATE228189T1; DE19534812A1; HUP9903803A2; PL325605A1; WO1997011228A1; NO981236L; CZ81698A3; HUP9903803A3; DE59609890D1; SK36798A3

Abstract

The disclosure pertains to a web-type tissue product with at least one unembossed substantially freely mobile middle layer, the layers of the tissue product being preferably joined to one another by join embossing common to those layers. The individual layers are smooth or provided with an embossed pattern extending substantially over the entire surface. The join embossing takes the form of embossed strips (4, 5) on both sides immediately adjacent to the edges (2, 3 ) of the multilayered web (1) and covering part of the web width (6). In a preferred embodiment, a number of pre-embossed outer layers (18, 20) are joined with a joining embossed pattern identical or similar in appearance to the layers´ embossed pattern.

Description

Multi-layer web-shaped tissue product with an embossed, essentially freely movable inner layer, its manufacture and device for its production

The invention relates to an at least three-layer web-shaped tissue product which has at least one unembossed, essentially freely movable inner layer between its outer layers, its production and a device for producing such a tissue product.

Within the scope of the present invention, an essentially freely movable inner layer or middle layer defines one or more inner layers which lie between the outer layers forming the two outer sides of the flat, multilayer tissue product and which are subjected to crimping or shear stress on the tissue product permits the outer layers to move relative to one another over a certain distance relative to the inner layer (s) without the cohesion of the product being changed or the product being destroyed.

This relative displaceability of the outer layers relative to the inner layer (s) gives the haptic impression of increased softness (subjective impression of softness), in particular increased softness of the tissue product compared to products in which this relative mobility is not guaranteed,

ORIG1NAL DOCUMENTS for example single-layer products whose basis weight corresponds to the sum of the basis weights of the individual layers of the multi-layer tissue product, since such single-layer products always have increased bending stiffness.

A relative mobility of the layers relative to one another in the sense of the definition is given if the layer attachment of the individual layers to one another is limited to certain areas or zones of the total area of the tissue product, for example zones parallel, along the cut edges of a roll product and this of the The area share serving for layer attachment makes up less than 50% of the total area of the tissue product / section.

The haptic impression of improved softness can be demonstrated by generating a shear stress, for example by the fingers of one hand moving against one another, which holds the tissue product between the thumb and the other 4 fingers.

Tissue product in the sense of the present invention means e.g. Toilet paper, towels and kitchen towels, in particular a corresponding toilet paper for at least three days, but also facial tissues and make-up removal towels.

DE-OS 1953878 relates to a paper laminate with high absorption capacity and high tear strength in the moist state, which is characterized in that the laminate consists of a layer of compressed, multilayer cellulose wadding which is water-resistant on at least one side with the aid of a binder with a layer Is coated crepe paper coated and a process for the manufacture of these paper laminates, wherein at least one layer of creped, waterproof tissue paper, which is to form the outer layer of the paper laminate and a layer of multi-layer cellulose wadding are pressed together by rollers between a pair of rollers after being pressed in between the rollers have a dispersion of a binder applied to at least one layer of the materials, on one side that comes to rest against the other material during the rolling. German Offenlegungsschrift 2455895 relates to a process for producing a multi-layer, absorbent paper wipe, wherein a continuous pattern of a water-resistant, reinforcing synthetic resin is applied to at least one side of a relatively inextensible middle layer of tissue paper, this pattern comprising between 15 and 50% of the total surface covered and at certain intervals on both sides of the middle layer an outer layer of a highly stretchable, creped tissue paper is glued to the embossing points formed on the said outer layers.

German patent specification 2149103 relates to a multi-layer composite material for absorbent paper towels, which is characterized in that an inner layer made of a creped absorbent cellulose wadding, which is extensible in at least one direction in the material plane, is sandwiched with at least one outer layer a creped absorbent cell wadding, which is less extensible in one direction, is connected, the or each outer layer being provided with projections spaced apart from each other and at least some of these embossments with the inner layer is connected by adhesive in such a way that unbound zones result between the connection points. From FIG. 1 and there in particular the reference numbers 7 to 10 and 17 to 20 respectively, it follows that the layer adhesion is given by two gluing units. This means that it is not possible for the central position to be freely movable. A similar situation can be found in US Pat. No. 3,738,905.

DE-A-4414238 relates to household or hygiene paper, consisting of at least one, preferably two to four layers of tissue paper, the paper being provided with an embossing, in particular for layer adhesion, which is characterized in that the household or hygiene paper is recalendered after it has been embossed and, if necessary, layered. In addition to this special post-calendering, this document sets out the subject of the present invention, such as stressed, not close, but especially not the unstamped freely movable middle layer.

From GB-A-2255745 a paper product consisting of at least two layers is known, in which the layers are at least partially embossed and connected with knurls, with dyes being arranged between the layers in such a way that a color appears points are visible at which the first layer comes into contact with the second layer. According to a preferred embodiment, the aforementioned laminate is formed from three layers, the outer layers being embossed and the middle layer being non-embossed, the outer layers being connected to the middle layer by a suitable adhesive. This publication also does not reveal the central position to be freely movable.

A method for producing laminated and embossed webs is known from German Offenlegungsschrift 1961528, two webs being embossed separately, each with a pattern of one to 30 elevations per cm ² and a height of 0.25 mm, at least on some of the elevations is applied by one of the above-mentioned sheets of adhesive, so that the above-mentioned sheets are arranged in such a way that the elevations are oriented towards one another and are offset from one another in such a way that an air volume is formed in the intermediate space and that one is used to unite the above-mentioned sheets Laminating pressure is applied while the elevations are supported on one of the webs mentioned. However, as can be seen in particular from the exemplary embodiments and figures, the layer is also arrested here by means of appropriate gluing, so that inevitably no freely movable middle layer can result.

DE-OS 3942536 and EP-A-0436170 relate to an embossed, multi-layer household or tissue paper, at least some of its layers being embossed independently of one another with one or more layers to form a rough and a smooth side, and which are independent of one another embossed layers by knurling tig are flush with each other that the outer sides of the outer layers are smooth.

EP-A-0264676 relates to a method for producing absorbent paper webs which has two outer layers and at least one inner layer, at least one of these paper webs being subjected to mechanical treatment, for example embossing, corrugation or folding, these webs together in an embossing station bonded together using adhesive and / or using mechanical means and the multilayer product thus obtained is then fed to a winding station.

According to the only exemplary embodiment for such a multi-layer tissue product, however, the middle layer is also fed to the embossing station, in which an embossing roller is assigned to a counter-roller.

A disadvantage of most of the aforementioned tissue products, which have a continuous embossing on all layers, is that the embossed knobs on the tissue product can be felt on the opposite side, which is not considered to be advantageous by the end user. Furthermore, such knobs are also regarded by the end user as little soft.

In the case of tissue products, the requirement for softness, in particular for body softness, and for fluffiness (surface softness) are usually in the foreground, and there must also be a certain minimum tensile strength required to meet the requirements for use.

It is an object of the present invention to provide a multi-layer web-like tissue product of the type mentioned at the outset, in which disadvantages, such as can occur in tissue products of a known type and as mentioned above, are eliminated. This object is achieved by a multi-layer web-shaped tissue product that, in addition to at least two embossed outer layers, it also has at least one non-embossed inner layer which is essentially freely movable.

The present invention therefore relates to a multi-layer, web-shaped tissue product with at least three layers with two embossed outer layers, which is characterized in that it also has at least one non-embossed inner layer which is essentially freely movable.

Compared to the prior art, this multi-layer, web-shaped tissue product has the following advantages:

A consumer-significant improvement in the softness (hand feel), in particular the softness of the wrinkles, due to a slight mobility of the individual layers relative to the areas connected by layer adhesion.

The mobility of the individual layers relative to one another is ensured in the case according to the invention by a reduction in the mechanical friction which occurs in the case of relative movements between embossed layers by the embossing knobs of the previously embossed outer layer of the tissue product on the surface of the tissue which is smooth compared to an embossing the unembossed middle layer can slide along without getting caught. The extreme contrast would be layers that are embossed together, whereby the embossing process itself causes the embossing sockets of the individual layers to already be in engagement with one another. In such a case, relative movements counteract higher frictional forces than when the embossed knobs slide on the relatively smooth surface of an unembossed central layer. The higher frictional resistance of the layers to one another is experienced haptically as a reduction in the softness, in particular the softness of the balls.

- Prevention of embossing knobs directed against one another during use (feeling through) by supporting them on the non-embossed middle layer (s). Increasing the tissue thickness of the tissue product by supporting the embossed knobs on the unembossed middle layer.

Improvement of the uniformity of the winding structure by equalization of the thickness despite the usual tolerances of the embossing due to the support of the embossing knobs on the non-embossed middle layer in the case of embossing not in register, with the result of an improved visual appearance if the tissue product is available as a roll product.

Strength increase by not stamping the middle layer (s) (avoid loss of strength by stamping).

The sandwich structure of the tissue product enables the implementation of functional concepts, such as the merging of different tissue qualities, i.e. for example soft outer layers and one or more solid, unembossed middle layer (s).

Furthermore, different embossing designs are possible on both outer sides of the tissue product in combination with one / more unembossed middle layers. A large number of different layer attachment methods, such as conventional knurling (edge embossing), wide knurling (wide track edge embossing), zone-by-layer layer gluing (structural laminating), their combination and a motif to generate layer attachment (spot embossing), possibly in a combination ¬ nation with gluing, possibly for decorative reasons with colored glue, can be used. However, this only lasts as long as the generation of the layer adhesion is limited to predetermined areas or zones of the tissue product and the mobility of the various individual layers relative to one another is maintained on the largest possible area when the tissue product is crumpled or other shear stress is applied. This area of essentially free movement of the layers is preferably the flat inner area of the multi-layer web-shaped tissue product or a section thereof, and the product is independent of the type of layer attachment generation of a previously applied embossing of the outer layers and has one or more non-embossed layers Inner layers. s

According to a preferred embodiment of the present invention, the multi-layer, web-shaped tissue product is predetermined in such a way that at least one of the outer layers, in the case of a roll product generally the outer layer facing the observer and facing the observer, has at least part of it Has surface applied (layer) embossing, which is independent of the layer adhesion generation.

According to a further preferred embodiment of the present invention, the multi-layer, web-shaped tissue product is predetermined in such a way that the outer layers have the same or different (layer) embossing or an embossing pattern on at least part of the surface, with the same embossing of both outer layers over the entire surface is particularly preferred.

According to a further preferred embodiment of the present invention, the multi-layer, web-shaped tissue product is designed such that the intensity of the embossing of the outer layers is the same or different for each outer layer, with a similar embossing intensity being particularly preferred for both outer layers.

A further embodiment of the tissue product according to the invention is characterized in that each of the two outer layers has at least two superimposed embossings, e.g. micro and macro embossing, possibly motif embossing, to produce certain functional properties, such as softness and volume (bulk), in combination with an optical appearance which is perceived by the consumer as interesting.

It is particularly preferred to arrange the layers in the multilayer, web-shaped tissue product according to the invention in such a way that the outer sides of the embossed outer layers are soft and the inner sides of the embossed outer layers are rough. According to a further preferred embodiment of the present invention, the multi-layer, web-shaped tissue product has a connection of the layers, for example by mechanical action, optionally also a layer adhesion produced by bonding, which is limited to a part of the total surface of the tissue product and thus creates sufficiently large zones in which the individual layers can move relative to one another under appropriate stress and which thereby have the impression of increased softness (subjective impression of softness, in particular increased softness of crumple) with sufficient bond strength for use. The distribution of the areas with layer adhesion can be zone-shaped, for example strip-shaped, narrow, as in the case of conventional knurling in the interior of the "cloth surface" of the tissue product of the tissue product section, parallel to the edge, one or more such knurling zones being common.

According to another preferred embodiment of the present invention, the strip-shaped area which has a layer adhesion can also have an enlarged width, such as, for example, in the case of a wide knurling with a strip width of 5 to 40 mm per strip or, together, 10 to 80 mm. Two such strips are then parallel to the cut edge of the multi-layer, web-shaped tissue product in direct connection to the cut edge and, corresponding to their width, extend from the cut edge into the interior of the surface of the tissue product.

In a particularly preferred embodiment of the multi-layer, web-shaped tissue product according to the invention, the knurling pattern of the knurling, in particular of the wide knurling, is matched to the embossing pattern of the layer embossing. This compensation of the layer embossing pattern and connection embossing pattern can be driven up to the identity and registration, which leads to an optical disappearance of the connection embossing in the pattern of the layer embossing. In practice, however, a more extensive adjustment is already sufficient, in which the zone of the layer adhesion visually no longer stands out from the layer embossing and no bulge which adversely affects the optics and haptics occurs due to the connection embossing. 40

A particularly advantageous embodiment of a multi-layer, web-shaped tissue product designed according to the invention, which is constructed from at least two previously embossed outer layers and one or more unembossed inner layer (s), is characterized in that it has an embossed pattern of a connection embossing which staples the layers together and the embossing pattern or patterns of the outer layers of the tissue product, which are formed by knobs (embossing knobs resulting from embossing in the tissue paper). These are arranged in an approximately rectangular or parallelogram-shaped, in particular square or rhombic, grid, the rows and columns of which are oriented approximately obliquely to the edges of the web (cut edge of the tissue product). With regard to the visual appearance, it is advantageous if the shape and arrangement of the embossed knobs of layer embossing and connection embossing in the outer layers of the tissue product largely correspond. It is particularly advantageous with regard to the achievable cohesion of the individual tissue layers by means of the embossed connection, if, in the aforementioned embodiment, it is provided that the knobs produced from the embossed tissue, an edge length determined on the end face with a polygonal cross-section (nub same as truncated pyramid) or diameter with a round cross-section (nub is equal to truncated cone) from 0.4 to 2.0 mm, preferably from 0.5 to 1.6 mm, particularly preferably from 0.7 to 1.5 mm . The front and foot surfaces of the knobs produced (shown) in the tissue can have a regular shape, e.g. N-angular, diamond-shaped, rhombus-shaped, square, square, round or oval, etc. In addition, the end and foot surfaces of the knobs can be designed irregularly in the form of any pattern.

In a further embodiment of the multi-layer, web-shaped tissue product according to the invention, the zones with layer adhesion are present in a relatively small area, ie in a spot-like manner (spot embossing, if necessary with structural laminating), these zones with layer adhesion evenly over the entire area of the tissue product are distributed that the mobility of the previously embossed outer layers relative to the unembossed middle layer (s) is maintained in the resulting gaps and these zones without layer adhesion similar to an air cushion to the one described ΛΛ

Improvement in softness and an improvement in the impression of volume.

In a further preferred embodiment, the multi-layer, web-shaped tissue product according to the invention can be post-smoothed or calibrated. By smoothing, i.e. under constant pressure or by calibration, i.e. the roughness peaks of the previous embossing (s) are eliminated by means of a constant spacing with the aid of a smoothing mechanism, whereby the surface softness is increased in addition to the improvement in the softness of the body according to the invention. The thickness of the tissue product is primarily equalized by calibration, which contributes to an improvement in the winding structure. The improvement in thickness is accompanied at the same time by an improvement in softness, which in many cases, however, lags behind the improvement in softness by smoothing.

According to a further preferred embodiment of the present invention, the embossing of at least one of the outer layers takes place in such a way that it is carried out by at least one embossing station in which an embossing gap is formed by a roller bearing a masculine nub with a steel surface of a counter-roller with a rubber surface, a plastic surface, a paper surface or a steel surface.

According to a further preferred embodiment, the multi-layer, web-shaped tissue product is such that the embossing of at least one of the outer layers takes place independently of one another by means of two embossing stations arranged one behind the other or one above the other, in which an embossing gap is formed in that a masculine nub load-bearing roller with a steel surface is assigned to a counter-roller with a rubber surface, a plastic surface, a paper surface or a steel surface. 41

According to a preferred embodiment of the present invention, the multilayer, web-shaped tissue product according to the invention has the same or a different tissue quality in the outer layers as the inner layer (s), the two outer layers particularly preferably in each case being the same and the inner layer (s) in addition to the feature not to be embossed, have a tissue quality that differs from the outer layers.

Tissue quality of a tissue paper layer in the sense of the present invention means such a quality which is selected from the group of tissue qualities which differ in their composition according to the type of fiber raw materials used, for example the origin of the cellulose from needles. , Hardwood or from annual plants, according to the chemical digestion process used, for example the sulphite or sulphate process, the type of feed to the tissue production process as dry pulp (in sheet form or flash dried) or as so-called pump pulp (in a consistency between 10 and 20%, as is customary in integrated pulp and tissue factories) or which differ according to the production process, such as, for example, production using the conventional tissue production process on a Yankee cylinder machine of conventional design or production using the TAD process (through air drying ). The selected tissue qualities can be produced layered or unlayered, creped or uncreped. The fiber raw material on which the selected tissue quality is based can originate from native fiber materials or come from recycled fibers (recycled fibers, waste paper), it can contain portions of synthetic fibers suitable for tissue manufacture or portions of chemically modified natural fibers, as well as its entirety or proportionally pulp from the group of wood pulp, ie for example ground wood, TMP (thermo-mechanical pulp), CTMP (chemi-thermo-mechanical pulp), HTCTMP (high temperature chemo-thermo-mechanical pulp).

In addition, the multilayer, web-shaped tissue products according to the invention include all those whose outer and / or inner layer (s) are made of tissue qualities were selected which contain one or more of the aforementioned features in any combination, certain properties of the tissue qualities used being able to be influenced in a targeted manner during the production process of preliminary or finished products by adding chemical auxiliaries. For example, the strength of the tissue quality used can be increased by adding dry and / or wet strength agents or the softness by using suitable plasticizers (softeners), optionally in combination with creping aids and the use of creping technology to promote softness, or the absorption capacity for liquids by adding absorption aids can be set to a desired dimension.

Such qualities in the multi-layer, web-shaped tissue products according to the invention are tissue papers, in which the outer and / or inner layer (s) can be selected from different basis weights in the range from 12 to 40 g / m ² , preferably 14 to 23 g / m ² , but especially from the range of 15 to 21 g / m ² per individual layer.

According to a particularly preferred embodiment of the present invention, in the multi-layer, web-shaped tissue product according to the invention, at least one of the layers, preferably one of the inner layers, should be at least 50% by weight, preferably at least 80% by weight, in particular up to 100% by weight. , Recycled paper or waste paper. Typical basis weight ranges of these paper qualities both for the inner and for the outer layers are basis weights of 12 to 40 g / m, preferably 14 to 23 g / m ² , in particular 15 to 21 g / m per individual layer.

According to a further preferred embodiment of the present invention, in the multi-layer, web-shaped tissue product according to the invention, the tissue quality of the inner layer or at least one of the inner layers should have a greater, equal or smaller strength than the corresponding tissue quality of the outer layers. Typical strengths of the inner layers are about 0.5 to 30 N / 50 mm, preferably 1.0 to 10 N / 50 mm and more preferably at 2.0 to 8.0 N / 50 mm in the machine direction and 0.5 to 6.0 N / 50 mm, preferably 0.6 to 4.0 N / 50 mm and in particular at 0.8 to 3.0 N / 50 mm in the cross machine direction. In contrast, typical strengths of the outer layers are lower, for example 0.8 to 20 N / 50 mm, preferably 1.0 to 8.0 N / 50 mm and in particular 1.5 to 7 N / 50 mm in the machine direction and 0, 5 to 4.0 N / 50 mm, preferably 0.6 to 3.5 N / 50 mm and in particular 0.8 to 2.5 N / 50 mm in the cross-machine direction.

It is very particularly preferred, however, in connection with the multi-layer web-shaped tissue product according to the invention, to provide additional cohesion by means of a connection embossing by at least one depression present on the surfaces, in particular the end face (s), of the knurled wheel knobs is preferably round or angular. In this context, it is preferred to proceed in the multi-layer web-shaped tissue product according to the invention in such a way that the layers are additionally held together by gluing applied to at least part of the web, preferably in the area of the wide knurl. However, this gluing is not carried out over the entire surface, but only to a maximum of 50% of the surface, so as not to impede the free movement of the middle layer.

Another object of the present invention is a method for producing a multi-layer, web-shaped tissue product, which is characterized in that between two outer layers, of which on at least one of the outer layers there is an (layer) embossing which extends over at least part of its surface area in one the independent process step preceding the generation of layer liability is applied, at least one non-embossed middle layer is arranged which is essentially freely movable.

A preferred method for producing the multi-layer, web-shaped tissue product according to the invention provides that both outer sides have an (layer) embossing which extends at least over part of the surface of the respective outer layer. 45

which is applied independently, before the layer adhesion is generated, the outer layers being embossing pattem with the same or different embossing, the use of a similar embossing pattern for the (layer) embossing of the Outer layers over their entire surface are particularly preferred.

According to a further preferred embodiment of the method according to the invention, it is provided that the embossing intensity of the embossing of the two outer layers can be set to be the same or different for each outer layer, with a procedural possibility of being able to set the embossing intensity for each individual outer layer independently of one another However, setting them the same for both outer layers is very particularly preferred.

According to a further preferred embodiment of the production method according to the invention, two embossments are superimposed on each of the two outer layers, the embossing patterns of the overlapping layer embossments being essentially technically predeterminable, with one outer layer first in each case in the successive method steps of the embossing receive a micro-embossing and then a macro-embossing, the macro-embossing possibly being a motif embossing.

Using a suitable combination of the selected embossing pattern / embossing method of the overlying layer embossing of the outer layers, functional product properties, such as strength, softness, volume, can be influenced with an optical appearance of the tissue product which is of interest to the consumer, whereby the procedural trick that To leave the central layer (s) unembossed, in conjunction with a connection of the layers to each other (layer adhesion area (s)) that is limited to only a portion of the total area of the tissue product (section), the essentially free mobility of the unembossed inner layer relative to the previously embossed External locations guarantees what leads to desired consumer-significant improvement in softness (softness) leads, as a subsequent consumer test shows.

According to a further preferred embodiment of the method according to the invention, the arrangement is such that the outer sides of the embossed outer layers are made soft and the inner sides of the embossed outer layers are rough. This means that the outer layers after the embossing when they are brought together to form the finished product are arranged in such a way that the embossed knobs produced by layer embossing in the tissue paper of the outer layers are aligned with the unembossed middle layer (s) from the outside of the later tissue product. The embossed nub tips, which are perceived as rough, are supported on the non-embossed middle layer, so that the opposing embossed nubs or approximately opposing embossed nubs do not get caught together, but can move relative to one another despite being embossed due to shear or bending forces acting on the outer layers, in that the embossed knobs of the outer layers can slide along the unembossed middle layer.

According to a preferred embodiment of the method according to the invention, this requirement is met in that the connection of the layers and the resulting layer adhesion is produced by mechanical action, optionally supported by additional gluing, the area of mechanical action (connection stamping) possibly being Connection with additional bonding to a part of the total surface of the resulting tissue product (section or demolition) remains limited and thus creates macroscopically large enough zones in which the individual layers can move relative to one another under appropriate stress, which gives the impression of the finished product Increased softness (subjective impression of softness), in particular the increased softness of the crumple with sufficient bond strength for use.

This method according to the invention allows a desired distribution of the areas with mechanical action to generate layer adhesion, in which the Areas with mechanical action according to a predetermined pattern, based on the surface of the tissue product (sections), taking into account aspects such as durability of the ply connection during manufacture and later use, simplicity of manufacture, good visual appearance, etc. According to a further preferred embodiment of the method according to the invention, the areas for generating layer adhesion by means of mechanical action with additional gluing, if necessary, are arranged in a zone-like manner, for example in a strip-like manner, so that these zones are parallel in the interior of the subsequent tissue surface (tissue product / section) run to the edge, the method providing for the creation of one or more such zones.

It is very particularly preferred that in the method according to the invention the strip-shaped region in which layer adhesion is generated by mechanical action, optionally supported by additional gluing, is to be made wide, strips with widths of 5 to 40 mm per strip or strips taken together from 10 to 80 mm (so-called wide knurling). In order to ensure that these strips with layer adhesion run parallel to the cut edge of the resulting, multilayer, web-shaped tissue product in direct connection to the cut edge and protrude into the interior of the surface of the tissue product (section), such a process provides mechanical action (for example in the form of wide knurling) before that after passing through the multi-layer processing machine-wide tissue webs with their previously embossed outer layers and one or more unembossed middle layers through a special connecting embossing station (wide knurling station) in which a relatively wide connecting embossing track (wide knurling track / zone) due to mechanical Action is generated, a winding process follows, in which a so-called "trunk" is wound, with a tissue web length corresponding to the number of sections prescribed for the tissue product, the last section being glued to the circumference of the St amms is attached. This trunk, the length of which corresponds to the width of the processing machine, is divided into narrow rolls in a subsequent operation by a knife or saw cut according to the desired tissue product width in such a way that the knife cut in comes to rest essentially in the center of the previously created connection embossing track (wide knurled track). This means that due to the method used, a strip-like area with layer adhesion must automatically start directly from each cut edge which runs parallel to each of the outer cut edges of the tissue product (section), tissue product being equal to rolls. Each of the two strip-shaped areas with layer adhesion has a width of 5 to 40 mm according to the invention, taken together 10 to 80 mm, when using this wide knurling, the method according to the invention having an essentially matching width at the edge zones (with layer adhesion).

Layer adhesion by mechanical action in the manner explained above is produced, for example, by a method with the aid of a connecting embossing station, in which the tissue web according to the invention, which consists of several tissue layers, is passed through a further embossing gap which is formed from two rotating steel rollers, by which a harder steel roller carries masculine embossed knobs, while the other, softer steel roller has a smooth surface and in which the roller bearing the masculine knobs is pressed against the smooth surface of the counter roller in such a way that the tissue layers of the tissue web located between the rollers are in the press nip at the locations where embossed knobs of the steel roller carrying knobs are deformed, the knobs of which are reflected in all tissue layers, so that the tissue layers leaving the press nip now themselves have knobs.

The intensity of the deformation in the tissue (knobs formed) and its plastic and elastic content depend on the moisture, composition, structure and physical properties of the tissue on the one hand and the specific surface pressure generated in the area of the knobs by pressing the rollers against each other . The surface pressure that can be generated is in turn a function of the number of knobs per unit area, the distribution pattern of the knobs, the knob geometry, in particular the size and shape of the end face of the knobs, as well as the formation of the knob flanks and the effective contact pressure. If the studded steel roller of the connecting embossing station is subdivided into narrow sections, one speaks of wheels from a certain ratio of the jacket length to the roller diameter. If these narrow roller sections serve exclusively to hold the layers of the individual tissue layers of a multi-layered tissue and do not cover these "wheels" with studs, they do not cover the entire width of the tissue web, but rather, as separate individual wheels, are limited in zones to certain locations on the tissue web so-called knurled wheels.

These knurled wheels (wide knurled wheels) of high hardness carrying the connecting embossed knobs are usually suspended individually and press against a mostly continuous white steel roller with a smooth surface and thereby form an embossing gap in which knobs are knocked on all tissue layers in every tissue position due to the mechanical action of the steel knobs are formed (shown), which slide into each other and interlock with one another, whereby in addition to mechanical interlocking of the roughness peaks of the tissue within the knobs formed at high surface pressure, “welding” of individual fibers to one another is also considered for the surface connection to one another. By further increasing the surface pressure to the extreme, an essentially desired additional perforation of the tissue layers is achieved, which further improves the layer adhesion, this perforation on the end faces of the embossed knobs or a part of these end faces, especially their edges are limited. Unwanted roughness of an outside of the tissue product that arises as a result is optionally eliminated by subsequent smoothing.

This zone-by-zone embossing by knurling can be made sufficiently firm to ensure the cohesion of the tissue layers, both over all stages of the manufacturing process that follow the knurling and when the tissue product is used by the end user for the intended use. 10

According to a particularly preferred embodiment of the method according to the invention, the embossing pattern for the layer embossing of the outer layers and the connection embossing, in particular in the case of wide knurling, is chosen to be identical or at least so similar that the connection embossing is largely invisible when the two embossments are superimposed .

In a further preferred embodiment of the method according to the invention, the embossing is carried out in such a way that the process of embossing the connection creates knobs in the tissue, which are arranged in an approximately rectangular or parallelogram-shaped, in particular square or rhombic grid, the rows and columns of which are approximately identical are arranged at an angle to the edges of the web (cutting edge of the tissue product).

With regard to the visual appearance, it is advantageous if the shape and arrangement of the embossing knobs of layer embossing and connection embossing in the outer layers of the tissue product largely correspond. It is very particularly advantageous with regard to the achievable cohesion of the individual tissue layers by means of the embossed connection if, in the aforementioned embodiment, it is provided that the knobs produced by the embossed connection from tissue have an edge length, determined on the end face, with a polygonal cross-section (nub = pyramid stump) ) or diameter with a round cross section (nub = truncated cone) of 0.4 to 2.0 mm, preferably 0.5 to 1.6 mm, particularly preferably 0.7 to 1.5 mm. The front and foot surfaces of the knobs produced (shown) in the tissue can have a regular shape, for example n-square, diamond-shaped, rhombus-shaped, square, square, round or oval, etc. In addition, these front and foot surfaces of the knobs can also be designed irregularly in the form of any pattern.

According to a further preferred embodiment of the method according to the invention, the mechanical action with which layer adhesion is produced, possibly in conjunction with gluing, is measured on a small area, measured on the total area 2. 4

A portion of the tissue product is limited to punctiform areas that are evenly distributed over the entire surface of the tissue product in such a way that in the resulting gaps the mobility of the previously embossed outer layers relative to the unembossed middle layer (s) is maintained and these zones without layer adhesion similar to an air cushion lead to the described improvement in softness and an improvement in the impression of volume.

According to a further preferred embodiment of the method according to the invention, post-smoothing or calibration takes place, which leads to a further improvement in the impression of softness and the winding structure.

According to a further preferred embodiment of the manufacturing method according to the invention, the finished product is created by a chronological sequence of several procedural steps to be determined, which are implemented by the mechanical installation of the processing line (processing machine or plant).

The following process steps are typical for the first quasi-continuous part of the production process according to the invention:

- Provision of suitable raw tissue qualities, single-layer or multi-layer doubled;

- separate unrolling of mother rolls from single-layer or multi-layer doubled raw tissue;

- separate management of the tissue rolls for the outer and inner layer (s);

- separate regulation of speed and web tension, separately for outer and inner layer (s) and for each process step, guided by a first layer embossing plant and depending on the connection embossing station, possibly gluing;

- Wide stretches of individual webs, possibly of the network, to avoid wrinkling through transverse contracts;

- separate, if necessary joint embossing of the outer layers to produce a layer embossing; 12th

- feeding the unembossed middle layer (s);

- Combining the layers and connecting the outer layers, which may be embossed over the entire surface or over part of their surface, with the unembossed middle layer (s) by mechanical action (connection stamping), optionally in conjunction with additional gluing, the mechanical action by conventional means Knurling or preferably by wide knurling takes place;

- printing if necessary;

- If necessary, insertion of winding cores (sleeves);

- If necessary, attachment of the first section to the winding core by first sheet gluing;

- dividing the tissue composite web into sections (single sheets) of the tissue roll product by means of perforating cross cuts;

- winding the tissue composite web into stems with the desired number of sections in the end product on a predetermined diameter;

- cutting off the trunk when the number of sections has been reached;

- Gluing the end sheet.

The process steps which are used in the discontinuous part in the context of the process according to the invention essentially include:

- ejecting and transporting the logs;

- storing logs in a log storage;

- Divide the logs according to the number of benefits possible from the log length (raw tissue web width on the mother roll) and the roll width (finished product) by cutting off with a knife or saw cut, the separating cut according to the invention in the middle, in each case in a paper-running direction with layer adhesion , preferably with a connection stamping, particularly preferably in the middle in a wide knurled zone;

- Collecting, transporting, stacking, packing the rolls, merging them into large containers, if necessary stacking on transport pallets according to the needs of the market. Experiments on the development of the process technology according to the invention have shown that an unexpectedly high level of control engineering is required if tissue layers of different working capacities (force / elongation behavior) are to be unrolled separately and then processed together. This was shown in particular when merging several individual layers if, as is provided according to the invention, different raw tissue qualities are selected for the different layers. The raw tissue webs provided as outer layers are embossed in an upstream process step, and these are then subjected, together with the unstamped inner layer (s), to a process in which mechanical action, optionally supported by gluing, a layer adhesion between the layers is generated so that, for example, embossing or non-embossing means that previously existing differences in length (elongation) of the individual layers in the composite can no longer be compensated for. Without such an individual regulation of the speed and tension of each individual web (tissue layer) in connection with the corresponding spreading of each web, starting from the unwinding over each station representing a single process step up to the winding, a production of end products with an unembossed middle layer proves to be less than desirable .

The control strategy for a preferred embodiment of the method for producing a multi-layer, web-shaped tissue product according to the invention with an unembossed central layer, which is essentially freely movable, has to meet the requirement that the speed of each individual layer of the multi-layer tissue product to be produced at the inlet of the connection embossing station ( Knurling or wide knurling station) is the same and this is related to the transport speed of the connection embossing station (circumferential speed of the driven embossing roller) in such a way that the tensile stress in each of the supplied tissue webs (individual layers) almost takes the value zero, so that different length changes individual layers as a result of different force / strain behavior, for example, the embossed outer layers relative to the unembossed middle layer (s) should be avoided before entering the connection embossing station.

The control strategy of a method for producing a tissue product according to the invention therefore provides that the speed of the unwinding (peripheral speed of the mother roll) belonging to the two embossed outer layers (peripheral speed of the mother roll) associated with the master drive of the “leading” first layer stamping station is so driven readjust that a desired tensile stress that can be predetermined for this tissue web can be kept constant.

From the master drive of this first ply embossing station, the speed of the subsequent connecting embossing station (knurling, if appropriate, wide knurling station) is regulated in a forward control with a small positive difference in such a way that the tensile stress occurring in this tissue web (ply) between the first ply embossing and the following one Connection stamping station almost takes the value zero. A positive difference means that the speed of the connecting embossing station is only slightly higher than that of the leading position embossing station, which is sufficient to hold and transport the tissue web without significant stretching and without wrinkling or sagging.

The control strategy of a method for producing a tissue product according to the invention further provides that the web tension of each further tissue web which forms a layer of the tissue product according to the invention (beyond the outer layer already described) is regulated via the speed of the respective upstream station, guided by the speed of the connection (knurling, if appropriate wide knurling) station.

This means that the circumferential speed of the unwinding (s) for the unembossed inner layer (s) is regulated in dependence on the (circumferential) speed of the connection embossing (knurling, possibly wide knurling) station in such a way that the occurring web tension remains essentially constant and almost assumes the value zero. For this purpose, the speed of this unwinding (s) is chosen to be slightly lower than that of the connecting embossing station, in accordance with the criteria described above.

In the case of the second embossed outer layer (n, if several outer layers are embossed together), the speed of the drive of the upstream layer embossing station is first regulated in dependence on the speed of the connection embossing station so that the transport speed of the tissue web (s) remains essentially constant and with which the connection embossing station (knurling or wide knurling station) essentially coincides, the peripheral speed of the ply embossing station being chosen to be slightly lower than that of the connection embossing station, so that a tension (web tension) is set between these two stations which almost reaches the value zero .

The layer embossing station of the second embossed outer layer (s) then takes over the management of the upstream associated unrolling in such a way that the unwinding of the unwinding, the peripheral speed thereof, is adjusted as a function of that of the ply embossing station in such a way that one for the tissue web ( en) specifiable, desired tensile stress can be kept constant.

The transport (peripheral) speed of all stations following the connection stamping station are conventionally regulated according to the state of the art.

The use of several separate unwinds and, in particular, a high level of technical complexity have hitherto been unusual in conventional processing plants. The present invention is also based on the object of providing a device for producing tissue products of the aforementioned type, comprising means for unwinding mother rolls 21, 22, 23 and means for determining and regulating web tension 44, 45, 46 and transport speed (Peripheral speed of driven rollers / master rolls), if appropriate for each tissue web individually, if appropriate from station to station between unwinding, first layer embossing, subsequent connection embossing and, if appropriate, further subsequent stations, if appropriate via controllable individual drives and means for and guiding the tissue webs 18, 19, 20 , a first (layer) embossing station 24, consisting of at least two separate embossing units, for the tissue webs 18, 20, a further (connecting) embossing station 25, which forms an embossing gap in which a plurality of narrow embossing rollers 26, optionally knurled wheels or preferably wide knurled wheels are assigned to a counter roller 27 and also contain means for spreading the individual tissue webs and the tissue product web, if appropriate between each station, optionally a smoothing unit, optionally a printing station and a roll-up station 28.

Such a device preferably contains a first layer embossing station 24 consisting of at least one pair of rollers, in which a roller with a steel surface which carries masculine knobs is assigned to a roller with a rubber surface, a plastic surface, a paper surface or a steel surface.

The smoothing unit itself is optionally designed in such a way that the tissue web is guided once through the nip (or several nips in a row) of a pair of rollers, optionally several pairs of rollers, in which first a smooth roller with a steel surface, a smooth counter-roller with a plastic surface and then a smooth roller with a plastic surface is assigned in mirror image to a smooth counter-roller with a steel surface (soft smoothing).

Furthermore, the smoothing can also be carried out in such a way that a smooth roller with a steel surface is assigned to a smooth counter-roller with a steel surface.

The printing unit is used, for example, to apply a pattern, lettering, logo, etc. 2?

The feeding of the tissue webs from the unwinds to the embossing stations (embossing station 24) in the case of the outer layers as well as all other webs including the unembossed middle (inner) layer (s) to the connecting embossing station 25 and the guidance of the tissue product web through further subsequent stations ¬ follows in a preferred embodiment of a device for producing a tissue product according to the invention preferably by means of the speed and the elongation behavior of the embossed tissue webs compared to the unembossed web (s) depending on the speed of a first ply embossing station and regulate that of the connection embossing (knurling, possibly wide knurling) station, for example by individual unrolling with corresponding tension controls, web guides including spreading devices.

It is further preferred that the first layer embossing stations serve exclusively for embossing the outer layers, that is to say that the middle layer (s) remain (are) unembossed.

For the purposes of the present invention, preference is given to a device in which the further connection embossing station 25 is a knurling station in which a knurling wheel roller or a plurality of knurling wheels, optionally wide knurling wheels, is assigned to at least one counter-roller with a steel surface, a rubber surface, a plastic surface or a paper surface . In this part of the device, the knurling wheel roller particularly preferably has knurling wheels which produce a wide knurling, that is to say knurling over a width of 10 mm to 80 mm, preferably 20 mm to 60 mm, per track. This means that these wide knurled wheels create flat zones (“traces”) oriented in the longitudinal direction of the tissue product web with a layer adhesion effective over all tissue product layers, in that the wide knurled wheel knobs are formed in the tissue webs by mechanical action on the tissue during operation of the device leave correspondingly shaped knobs in each tissue layer of the tissue product web, which secure the layer bond by frictional engagement, if necessary mechanical hooking. 2g

It is particularly preferred in this connection that this part of the device for producing a tissue product according to the invention is designed such that the knobs of these wide knurled wheels (FIGS. 4, 7, 8, 9) have depressions on at least part of their surface, in particular their end face . These recesses are in particular designed such that they have a multiplicity of polygons or circles, preferably rectangles or parallelograms.

Such depressions are held so that they are present in particular in the form of fine notches in the knurled knob surface. Compared to the knurled knobs with a smooth surface described above, the knurled knobs with a recess surprisingly have the advantage for the person skilled in the art that they produce a significantly greater layer adhesion, with the tissue webs to be connected in the grooves due to the many edges and notches during the pressing of the various tissue layers, a significantly higher fiber composite can be achieved.

Typical geometries 31 for depressions present on the end faces 30 of the knurled knobs are both only narrow depressions with a rectangular or V-shaped cross section, possibly with rounded lower edges, but also a combination of narrow depressions with wider depressions, but the recesses being smaller smooth surface of the embossed knobs should be kept as low as possible. A good additional layer adhesion can be achieved by an embodiment with narrow depressions, preferably depressions arranged crosswise. These depressions should make up less than 50%, preferably less than 30%, of the non-recessed surface.

All other details of a preferred embodiment of a device for producing a tissue product according to the invention, in particular details of the wide knurling device such as the arrangement of the knurled (embossed) knobs, knob geometry, dimensions, design and fine structure of the knob end face 30 of the individual knurled wheel knobs as well the inclination of the network structure to the edges of the end face the corresponding detailed descriptions of preferred embodiments for tissue products and methods according to the invention.

A further preferred embodiment of a device for producing a tissue product according to the invention contains means for applying a sizing agent, adhesive or, if appropriate, hotmelts for punctiform or thread-like application, if appropriate according to a pattern at least in the area of the wide knurling to support the generation of layer attachment by mechanical means Impact.

The invention will now be further explained with reference to figures which are shown schematically in the drawing.

Show it

FIG. 1 is a top view of the surface of a section of a narrow web that has already been cut longitudinally of a multi-layer tissue product designed according to the invention,

FIG. 2 shows a part of a trunk of a wound, multi-layered tissue product according to the invention, which is intended to be divided into rolled webs of a tissue product designed according to the invention by separating cuts,

FIG. 3 shows an example of a device which is provided for the production of a multi-layer web-like tissue product designed according to the invention,

FIG. 4 shows a top view of the end face of an individual knurled knob with the pattern of depressions located thereon (exemplary, schematic, in high magnification),

FIG. 5 shows an example of an alternative device which is provided for the production of the web-shaped tissue product designed according to the invention, and FIG. 6 shows an example of a further device which is provided for the production of a web-shaped tissue product designed according to the invention.

FIG. 7A shows a plan view of an enlarged section of the surface of the embossing roller to produce a position embossing of the tissue product outer layers according to the invention, showing the pattern of the embossing knobs with a rounded foot zone,

7B shows a section A-A from FIG. 7A, illustrating the shape of the embossed knobs with a flat end face and a rounded foot zone

8A shows a plan view of an enlarged section of the surface of an alternative embossing roller for producing a layer embossing of the outer product layers according to the invention, which represents an alternative pattern of alternative embossed knobs with a sharp-edged foot which are spaced apart from one another.

FIG. 8 B shows a section B-B from FIG. 8 A, illustrating the shape of alternative embossed knobs (truncated pyramids) with a flat end face and a sharp-edged foot,

FIG. 9A shows the combined cross section / top view of a wide knurled wheel with a diameter and width marking,

9B shows the enlarged section of detail B from the surface of the wide-knurled wheel according to FIG. 9A, illustrating the arrangement and shape of the knurled embossed knobs for producing a connection embossing for a tissue product according to the invention,

9 C shows the further enlarged detail of the detail C from FIG. 9 B, exemplifying the fine structure of the diamond-shaped end face of a knurled embossed knob for wide knurling in combination with fine knurling, created by the incorporation of linear depressions into the initially flat surface of the end face of these knurled knobs, see above that a cross-lattice network of sharp-edged depressions covers the end face. Tissue narrow web 1, of which a section is shown in FIG. 1 in view of the fully embossed surface of an outer layer of the tissue cut to the final product width, consists of several, for example three or more, preferably three to four, layers, which are preferably joined together by an additional connection embossing common to these layers is stapled together in the areas 4, 5. This connection embossing is in the form of embossing strips 4, 5 which directly adjoin the cut edges 2, 3 of the multilayer web on both sides and which take up part of the web width 6. With usual narrow web widths of approximately 90 to 120 mm corresponding to the end product width, for example of a toilet paper roll (corresponding to its section / sheet width), the width of the embossing strips 4, 5 can be selected in total, for example, with approximately 10 to 80 mm, preferably 20 to 60 mm. For larger web widths, for example 120 to 300 mm (for example kitchen rolls) and more, the embossing strips 4, 5 can also be made wider.

In the illustrated case, the embossing pattern present in the embossing strips 4, 5 of the connecting embossing that binds the layers of the tissue narrow web 1 together is formed by knobs 7, which are arranged in an approximately rectangular or parallelogram-shaped grid, the rows and columns of which are approximately equally inclined the cutting edges 2, 3 of the narrow tissue web 1 are aligned. The course of the rows by dash-dotted lines 9 and the course of the columns by dashed lines 8 are indicated in FIG. 1; the angles denoted by 10, which include the lines 8 with the cutting edges 2, 3, and the angles denoted by 11, which enclose the lines 9 with the cutting edges 2, 3, are approximately the same. Approximate equality of these angles is favorable for a straight run of the tissue web in connection embossing (knurling, if appropriate, wide knurling). A slightly helical course of the embossing knobs which follow one another in the circumferential direction is likewise advantageous.

Of the individual layers of the web-shaped tissue product, which are stitched together in particular by the connection embossing (knobs 7) in the form of the two embossing strips 4 and 5, the outer layers (webs) are each individually with a marked embossing pattern extending over the entire surface, whereas at least one of the inner layers is not embossed. In the interest of good optics and good grip (softness, in particular crumpling softness) and volume and a total thickness of the web-shaped tissue product that is approximately the same over the entire web width, it is advantageous to provide an embossing of the individual outer layers of the narrow tissue web 1 that extends over the entire surface . This is also realized in the example shown in FIG. 1. In this example, the layer embossing patterns are largely identical to the embossing pattern of the connection embossing, which, in addition to the technical advantage that the multilayer tissue narrow web has approximately the same properties everywhere, also has the advantage that the embossing strips 4, 5 hardly differ visually Lift off the embossing pattern of the zone between these embossing strips without layer attachment 14.

If, for example, one chooses the mutual distances 12 that exist between the lines 8 and the mutual distances 13 that exist between the lines 9 differ in size, this is for a uniform engagement of the knobs of the connection embossing rollers (knurled if necessary, wide knurled wheels) in the tissue layers to be united and thus advantageous for a smooth running of the connection embossing process. If there are only slight differences between the distances 12 and 13, resulting in an approximately square or rhombic grid in which the knobs forming the embossed pattern of the connection embossing are arranged, this gives a largely similar appearance in the central zone 14 to the appearance of the embossed pattern on the one hand, where only the surface embossing of an outer layer of the narrow tissue web can be seen, and the embossing pattern of the connection embossing present in the embossing strips 4, 5, on the other hand. The embossing recognizable in the top view (embossing knobs in the tissue are schematically marked as black dots) in the embossing strips 4, 5 accordingly represents the superimposition of two embossings which have arisen independently of one another, namely the layer embossing also present in the central zone 14 and the connection embossing with which the individual layers, which together form the narrow tissue web 1, are stapled together. The dimensions of the individual knobs which form the embossing pattern are advantageously chosen such that the edge length or the diameter of the end face of these knobs on the tissue web is in the range from 0.5 to 5 mm, preferably 1 to 2.5 mm, in particular is preferably less than 1.5 mm.

In the production of the web-shaped tissue product, the procedure is such that several embossed tissue outer webs together with at least one non-embossed tissue inner web, the width of each of which is a multiple of the width of the narrow tissue web to be produced, together by means of an axially divided connecting station, preferably one Embossing gap, in which the stitching of these tissue webs into a multi-layer "tissue product web" is brought about by means of a connection embossing. The connection embossing thereby forms a plurality of embossing strips 16 spaced apart from one another. The multi-layer tissue product web stitched together in this way then becomes one Stem 15, a part of which is shown in Figure 2. Embossed strips 16, which are separated from one another by zones 14, are provided in this processing machine-wide tissue product web wound into a stalk 14. Stem 15 is then cut , which are guided with saws and knives approximately in the middle of the embossing strips 16, as indicated by dash-dotted lines 17, divided into a number of rollers with a smaller axial length. These have the width intended for the use of the tissue product and contain a wound-up narrow tissue length which results from the section (sheet) length determined by perforation cut and the specified number of sheets.

In the device shown schematically in FIG. 3 with 3 unrolls, three single-layer tissue webs 18, 19, 20 are each processed separately from so-called mother rolls 21, 22, 23, and the tissue webs 18 and 20 are guided through an embossing station 24, in which these tissue webs each can be seen individually with a layer embossing. With this device, each of these webs can be embossed independently of one another according to pattern and intensity, or the webs can also be embossed by lifting off the associated embossing rollers stay. The layer can be embossed over the entire surface or restricted to certain areas of the tissue layer, which are distributed according to a predeterminable pattern, or decorative embossing can be carried out in the manner of a spot embossing. Thereafter, these embossed or unembossed tissue webs 18, 19, 20 are guided together through a further embossing station 25, where these tissue webs pass as they pass through an embossing gap which is formed between a plurality of narrow embossing rollers, optionally knurling or wide knurling wheels 26 and a counter roller 27, the tissue webs 18, 19, 20 being stitched together to form a three-day “tissue product web”. This three-layer tissue product web is then fed to a take-up station 28, where this tissue product web, the width of which contributes a multiple of the axial length of the finished paper rolls to be produced, is fed Logs are wound as shown in Fig. 2. As mentioned in connection with Fig. 2, this wide tissue product web is then divided according to the dash-dotted lines 17 into individual finished narrow rolls, the dimensions of which correspond to the intended use.

In the course of this manufacturing process, additional processing or manipulation can also be carried out, e.g. gluing the individual tissue product web to be rolled up into logs 15 to winding cores 29 (not shown here), securing the end lying in the trunk 15 with adhesive, if desired printing the tissue product web, for example after it has been stitched together to form a multilayer web by means of embossing , or putting paper loops around the finished logs. The supplementary processing steps also include dividing the tissue product web into sections of the desired length (individual sheets of the tissue product) by means of a perforated cross section.

In order to control the embossing process of the connection embossing, it is advantageous to provide a controllable pressure of the embossing rollers, optionally knurling or wide knurling wheels 26 on the counter roller 27. For example, a pneumatically working, controllable pressure device can be used for this. FIG. 4 shows the top view of a truncated pyramid-shaped knurled knob with a square end face 30, which has at least partially depressions 31. In this exemplary embodiment, the depressions 31 are designed in the form of a net as fine depressions each in a rectangular shape, the depressions being oriented obliquely to the boundary edge of the end face and producing a checkerboard-like pattern on the end face.

In the device with 2 unwinds shown in FIG. 5, a three- or four-layer, web-shaped tissue product can be produced in such a way that the two outer layers are presented doubled for two days, but separately embossed, and one or two middle layers are not embossed can be created. This takes place in such a way that, in the device shown in FIG. 5, three tissue webs 32, 33 and 34 are processed from so-called mother rolls 35 and 36 provided, and tissue webs 32 and 33 are each guided through an embossing station 37, in which these tissue webs are separated can be embossed. In contrast to this, tissue web 34, which can be designed as a single-layer as well as double-layered, is passed between the two layer-embossing rollers of the first embossing station 37 without embossing this layer (s) and then embossing it together with the two embossed layers Outer layers 32, 33 are fed to a further, downstream connection embossing station (not shown here) analogous to 25 in FIG. 3, in which the desired connection embossing (optionally knurling or wide knurling) which is limited to a part of the total area of the Tis¬ web is produced, which the Individual layers are joined together by mechanical action, the latter possibly being supported by additional gluing. On the way to the first ply embossing station 37 and further to the connecting embossing station, deflection rolls in the form of dancer rolls 35A, 36A (corresponding to the reference numbers 44, 45, 46 in FIG. 6) are in each case in the position to be embossed as well as in the non-embossed position. provided that serve to compensate for the different tensile forces resulting from embossing or non-embossing and to provide the necessary control impulses for the respective speed control 56

Find. Wrinkling can thus be prevented, which would otherwise lead to a deterioration in the appearance.

In the device shown in FIG. 6 with 3 separate rolls, both a three- and a four-layer tissue product can be produced, two or three layers of which are embossed separately and one or two middle layer (s) are obtained without being embossed. Here the outer tissue layers 38 and 40 are each fed to a first embossing station 47 with two embossing stations via a system of dancer rollers 44 and 46 and deflection rollers from the corresponding mother rollers 41 and 43, respectively. In addition, a tissue layer 39, which in turn is unwound from a mother roll 42 by means of a deflection roller system with a dancer roller 45, passes the embossing station without embossing and is then fed to a connecting embossing unit analogous to 25 in FIG. 3. Depending on the tissue product to be produced, the mother rolls 41, 42 and 43 are specified either in one layer or in two days. For example, the parent roll 41 can be specified in one layer, then the parent roll 42 is single-layer or two-layer and the parent roll 43 is single-layer. Furthermore, the mother roll 41 can be specified in two layers, and then the mother rolls 42 and 43 are each in one layer. If the master roll 41 is specified in one layer, the master roll 42 will also be available in one layer and then the master roll 43 will be available in two layers.

FIG. 7A shows the planar development of an enlarged section of the surface of a particularly preferred embodiment of a metallic embossing roller (steel) for producing a layer embossing of the outer layers of tissue product according to the invention in supervision. The drawing shows the pattern of the embossed knobs in vertical supervision, with their square end face 48 and the side edges emerging from the corners of the end faces, each knob being formed as a truncated pyramid, the end face of which is essentially flat and the leading edges of which are sharp-edged, the foot zone is rounded off, however, so that the foot zones of embossed knobs arranged next to one another merge smoothly into one another. The embossing knobs are arranged in rows on the embossing roller surface in such a way that the same edges of the end faces of the next neighboring embossing knobs, seen in the direction of fall over the knobs flanks, 3?

come to lie on parallel lines which are aligned obliquely at an angle with respect to a surface line of the substantially cylindrical embossing roller. The center points of the end faces of embossing knobs which follow one another in the circumferential direction of the embossing roller are arranged on the same circumferential line, the diagonals of the square end faces of the embossing knobs coinciding in the direction of rotation of the embossing roller with a circumferential line and transversely with a surface line. The alignment of the embossing knobs to a surface line of the embossing roller is 45 ° in the preferred embodiment shown, but can deviate therefrom. The regular arrangement of the embossed knobs defines a grid pattern in which the reference number 49 denotes the length of the side edges of the essentially square end faces of the embossed knobs, and the reference number 50 the distance between two parallels to the same end face edges on a line perpendicular to the next adjacent embossing represents pimpled, these parallels being inclined at a characteristic angle of preferably 45 ° against a surface line of the embossing roller. The reference number 51 represents the grid spacing of the next adjacent embossing knobs, which are arranged on parallel circumferential lines. AA is a reference line along which a cut is made perpendicular to the flat development of the roller surface, in which 3 embossing knobs which follow one another on the oblique reference line be cut so that the contour of the knobs is visible in a side view.

FIG. 7B shows the contour of three embossing knobs from the surface of an embossing roller, the planar development of which is shown in detail in FIG. 7A, along the section line A-A. In FIG. 7B the sharp-edged transition from the flanks to the end face and the rounding of the knobbed foot can be clearly seen, reference numeral 52 representing the knob height and reference numeral 53 the flank angle along the falling line as the angle between the falling line and the normal intersecting it.

8A shows, analogously to FIG. 7A, the planar development of an enlarged section of the surface of an alternative embodiment of a metallic embossing roller (steel) for producing an alternative layer embossing according to the invention of the outer layers of tissue product in supervision. The drawing again represents the pattern of the 58

Embossed knobs in a vertical view and also shows square end faces analogous to reference number 48 in FIG. 7A. The embossed knobs are designed as truncated pyramids, in contrast to FIG. 7A but with a square foot surface, delimited by sharp edges and not rounded as in FIG. 7A Foot. The individual embossed knobs are at a small distance, measured as the distance 54 between parallel edges of the foot surfaces of two adjacent embossed knobs, isolated from one another on the cylindrical base of the embossing roller. The end faces of the embossing knobs are essentially flat in relation to the flat development, so that in reality they form partial surfaces from a curved cylindrical surface corresponding to the outermost circumference of the knob-bearing embossing roller. The reference number 56 indicates the edge length of the square end face of the embossed knobs, the reference number 55 indicates the edge length of the likewise square foot surfaces of the truncated pyramids. Analogously to FIG. 7A, the center points of the end faces of embossing knobs which follow one another in the circumferential direction of the embossing roller are also arranged on the same circumferential line in FIG. 8A, the diagonals of the square end faces of the embossing knobs in the rotational direction of the embossing roller each having a circumferential line and transversely for this purpose coincide with a surface line, the distance between two circumferential lines marked in this way forming the grid spacing of the grid, which is identified by reference number 57. Parallels to the section line B-B and the lines perpendicular thereto form, with a surface line, also analogously to FIG. 7A, an angle which is essentially 45 ° in the preferred embodiment of the embossed embossing pattern shown, but may deviate therefrom if necessary.

FIG. 8B shows the contour of three embossing knobs from the surface of an embossing roller, the flat development of which is shown in detail in FIG. 8A, along the section line BB. 8B shows the sharp-edged transition from the flanks to the end face and the likewise sharp-edged transition of the foot part of the knobs, which in contrast to FIG. 7B is not rounded, to the bottom of the knock-bearing embossing roller, which in reality is cylindrical. The reference number 58 designates the nub height, the reference number 59 the flank angle of the equilateral pyramids of the embossed nubs 33

in analogy to 63 from FIG. 7B, both the angle 59 being greater than the angle 53 and the knob height 58 from FIG. 8B exceeding the knob height 52 from FIG. 7B.

FIG. 9A schematically shows the combined cross section (top) and a top view (bottom) of a wide knurled wheel, reference number 60 representing a surface line of the outermost cylinder surface of the knurled wheel carrying the knurled knobs as a reference line, the distance to the lower limiting surface line indicated by arrows ¬ is drawn, which mark the diameter of the knob-bearing wide knurled wheel. The wide knurled wheel consists of an annular casing 61 which is fastened by suitable means 62 on an axis of rotation 63 (not shown here). The inner diameter of the annular knurled wheel casing is identified by reference number 66, the width of the knurled wheel casing is identified by reference number 68, an inner part 64, which is the same on both sides, being slightly drawn in to a smaller width, as shown by reference number 67. Reference numeral 65 indicates the diameter of the circular center line on which all the bores are located, which are provided for fastening the knurled wheel jacket on a shaft serving as an axis of rotation. Detail B as a cutout of the outer surface of the knob-bearing wide knurled wheel casing is shown in FIG. 9B on a larger scale.

FIG. 9B shows the flat development of a surface section with knurled (wheel) knobs in a large enlargement, which in a process analogous to the layer embossing by the generation of a deformation of the tissue web which becomes effective through all the tissue layers of the tissue product, embossed knobs in the throat Ue sue forms that mechanically connect the individual layers. Detail B shows the diamond-shaped end faces 69 of the knurled knobs made of hardened steel, which in the particularly preferred embodiment shown here are arranged in such a way that a diamond-shaped grid results, the knurled knobs following one another in series so that the resulting connecting lines of the same or parallel edges of the knob end faces to a surface line on the outer circumference of the knurled wheel at an angle 71 in one main direction and at one opposite χ0

71 smaller angles 71 A to the other main direction with respect to the surface line serving as reference are shown. This minimal oblique alignment of the knurled knot pattern with respect to the running direction of the knurled wheel has proven to be particularly effective in preventing wrinkling in the tissue during production. The distance 70 that results between parallel reference lines of the same edges of the end faces of successive knurled knobs to those of neighboring knurled knobs is the same in the particularly preferred embodiment shown. The distance 69 A between parallel edges of the diamond-shaped end faces of each individual knurled knob 69 is the same and, in a particularly preferred embodiment, has a value of less than 2 mm.

FIG. 9 C shows the further enlarged detail of the detail C from FIG. 9 B. This detail represents the diamond-shaped end face of an individual knurled knob, which in this strong enlargement has a fine structure similar to that of the knob arrangement on the surface of the wide knurled wheel. This "fine knurling", which is a very particularly preferred embodiment of the device according to the invention, consists of a cross-grid-shaped network of notch-like depressions with a V-shaped or rectangular cross section, optionally with the lower part of the depression directed towards the center of gravity of the knurled knob 9c, the two side edges 71 of the end face of a knurled knob are of equal length. The mesh-like depressions leave rows of essentially square or in a further embodiment (here (not shown) diamond-shaped elevations which remain as remnants of the originally essentially flat end face of each individual knurled knob when the recesses are finely engraved. These resident subareas of the knurled knob surface are arranged in rows like the knobs themselves, whose grid division is identified by the reference number 73 as being the same. As FIG. 9C also shows, the rows of the resident subareas of each knurled knob end face are inclined at an angle 74 to the edge of the end face, which is of particular importance for perfect knurling without wrinkling in the tissue. The present invention is explained below by means of exemplary embodiments which have been obtained in connection with carrying out a consumer test.

In a consumer test, two different, commercially available 3-ply branded toilet papers against corresponding prototypes of 3-ply toilet papers according to the invention produced according to the invention were assessed under a reservation of secrecy.

The two commercially available brand toilet papers, pattern A and pattern C, differed in the fiber raw material used (recycled fibers from deinked waste paper) in such a way that the proportion of lower waste paper quality for the toilet paper according to sample A was higher than that for the production of toilet paper according to the sample C, recognizable from the outside by a significantly lower whiteness of pattern A compared to pattern C.

Furthermore, the two commercial branded toilet papers differed in basis weight in that toilet paper according to sample A had a basis weight of 17.5 g / m ^{2 for} the individual layer, those according to sample C had a basis weight of only 17.0 g / m ² and layer.

The structure of the two commercially available products in 3 layers, which were connected to one another in the form of strips in the longitudinal direction of the tissue paper web by mechanical action, was of the same type, the manufacturing of the test goods being different from the usual production practice and better comparability because of the wide-knurled method according to the invention for producing layer adhesion has been.

The two commercially available toilet paper were each fully embossed according to the state of the art and equipped with a central layer, likewise embossed over the entire surface, whose embossed pattern matched that of the outer layers. Both toilet AI

papers according to sample A and sample C had the same embossing pattern as a full-surface "diamond embossing" analogous to FIG. 7A with the same embossing intensity.

In contrast to this, the comparison products to be assessed in a monadic test arrangement were prototypes of a corresponding toilet paper made from the respectively identical raw tissue quality with samples A and C, each with a comparable basis weight, but according to the invention with an unembossed middle layer (samples B and sample D) ). The outer layers of these prototype-like comparative products, pattern B and pattern D, had surface embossing comparable to patterns A and C with a comparable intensity.

The patterns described in this way were subjected to a monadic in-home test assessment (blind test without branding), as explained in more detail in non-fiction books on experimental marketing analyzes.

This included 2x2 structurally identical groups of 100 housewives, quoted in terms of age, employment, household size, location awareness, brand use, etc., who had used the corresponding toilet paper (sample A and sample C) during the past 12 months, while a trial period of 5 days for each toilet paper used to try out the following samples:

* one made of 100% waste paper 3-lg. Paper quality with the following characteristics:

- Weight per unit area of 17.5 g / m2

- All layers have a diamond pattern over the entire surface

- The layer attachment is generated by a wide knurling (pattern A)

* a 3-lg. Tissue paper quality as in pattern A, but with an unembossed middle layer instead of an embossed middle layer (pattern B)

* one made of 100% waste paper 3-lg. Tissue paper quality with higher whiteness than sample A with the following characteristics: - Basis weight of the individual layers 17.0 g / m2

- All layers have a full diamond pattern

- The individual layers are arrested by means of a wide knurl (pattern C)

* a 3-lg. Tissue paper quality as in pattern C, but with an embossed middle layer instead of an embossed middle layer (pattern D)

In conjunction with the product test in home, a supported evaluation was carried out and this was subjected to a significance test on the basis of property profiles. In a follow-up interview, a strengths / weaknesses analysis based on a spontaneous discussion was carried out by interviewing each test person in the following way:

“I have the two toilet papers that you tested here. Please tell me again spontaneously from memory what you liked about this toilet paper! "

After evaluation, sample B was assessed by the test subjects as significantly softer and more skin-friendly than sample A, i.e. 54% in favor of sample B versus 39% for sample A, whereas 7% considered samples A and B to be equally soft and skin-friendly.

In the same way, the aforementioned test was also carried out with the tissue paper qualities according to sample C and according to sample D. There, the tissue quality D was regarded by 73% of the consumers as significantly softer and more tear-resistant than pattern C, that is to say, pattern C was felt by only 27% of the consumers as softer and also more tear-resistant.

Claims

claims

1. Multi-layer web-shaped tissue product with at least 3 interconnected layers with 2 embossed outer layers (18, 20), characterized in that it also has at least one non-embossed inner layer (19) which is essentially freely movable.

2. Multi-layer web-shaped tissue product according to claim 1, characterized gekenn¬ characterized in that at least one of the outer layers (18, 20) has at least on a part of its surface applied (layer) embossing.

3. Multi-layer web-shaped tissue product according to any one of the preceding claims, characterized in that at least one of the outer layers (18, 20) has the same or different (layer) embossing or an embossing pattern on at least part of the surface.

4. Multi-layer web-shaped tissue product according to any one of the preceding claims, characterized in that each of the two outer layers (18, 20) has two superimposed embossments.

5. Multi-layer web-shaped tissue product according to any one of the preceding claims, characterized in that the arrangement of the layers is such that the embossed outer sides of the outer layers (18, 20) are soft and the embossed inner sides of the outer layers (18, 20) are rough .

6. Multi-layer web-like tissue product according to any one of the preceding claims, characterized in that it has a connection of the layers, for example via a layer attachment by mechanical action, where appropriate, supported by gluing, which is limited to part of the total surface area of the tissue product.

7. Multi-layer web-shaped tissue product according to any one of the preceding claims, characterized in that it has an embossed pattern of a connection embossing between the outer layers (18, 20) and the inner layer (s) (19).

8. Multi-layer web-shaped tissue product according to any one of the preceding claims, characterized in that the zones with connecting adhesion are relatively small in area.

9. Multi-layer web-shaped tissue product according to any one of the preceding claims, characterized in that the outer layers (18, 20) have the same or a different tissue quality as the inner layer (s) (19), the inner layer (19) preferably having a different tissue quality ¬ points like the outer layers (18, 20).

10. Multi-layer web-shaped tissue paper according to any one of the preceding claims, characterized in that the outer layer (s) (18, 20) have the same or a different material composition as the inner layer (s) (19), the fiber raw materials are entirely or predominantly recycled fibers from waste paper.

11. Multi-layer web-like tissue product according to any one of the preceding claims, characterized in that the weight per unit area of the outer and / or inner layer is in the range from 12 to 40 g / m ² , preferably 14 to 23 g / m ² and in the case of waste paper qualities, basis weights of 12 to 40 g / m ² , preferably 14 to 23 g / m ² , each in each case

Multi-layer web-like tissue product according to at least one of the preceding claims, characterized in that the inner layer has a strength of 0.5 to 30 N / 50 mm, preferably 1.0 to 10 N / 50 mm, in the machine direction and 0.5 to 6 .0 N / 50 mm, preferably 0.6 to 4.0 N / 50 mm, in the transverse direction of the machine and the outer layers have a strength of 0.8 to 20 N / 50 mm, preferably 1.0 to 8.0 N / 50 mm, in the machine direction and 0.5 to 4.0 N / 50 mm, preferably 0.6 to 3.5 N / 50 mm, in the cross machine direction

Multi-layer web-like tissue product according to at least one of the preceding claims, characterized in that the outer layer and / or the inner layer (s), which may have been creped, in their entirety or partly fiber materials from the group of the wood materials, like wood pulp, TMP, CTMP or HTCTMP included

Method for producing a multi-layer, web-shaped tissue product, characterized in that at least one unembossed middle layer is arranged between two embossed outer layers (18, 20) and is essentially freely movable

A method according to claim 14, characterized in that the outer layers (18, 20) are provided with the same or different embossing on at least part of their surface

Method according to the preceding claims, characterized in that at least one of the outer layers (18, 20) is embossed by at least one embossing station, in which an embossing gap is formed in that a roller with a steel surface and a counter roller with a rubber surface, plastic surface, paper surface or steel surface is assigned 4?

17. The method according to the preceding claims, characterized in that the embossing of at least one of the outer layers (18, 20) is carried out by two embossing stations arranged one behind the other, in which the embossing gap is formed in that a roller with a steel surface of a counter roller with a rubber, if necessary Plastic surface, paper surface or steel surface is assigned.

18. The method according to the preceding claims, characterized in that an unloading station is provided in connection to the first embossing station.

19. The method according to the preceding claims, characterized in that the arrangement of the layers in the tissue product takes place such that the embossed outer sides of the outer layers (18, 20) are soft and the inner sides of the embossed outer layers (18, 20) are rough.

20. The method according to the preceding claims, characterized in that a connection of the layers by an edge embossing, spot embossing or knurling, optionally wide knurling, optionally additional gluing, takes place.

21. The method according to any one of the preceding claims, characterized in that several, three or more, provided with a knob embossed tissue outer webs (18, 20), the width of which is a multiple of the width of the tissue narrow web (1) to be produced, together with at least one non-embossed central layer (19) are passed through an axially divided embossing gap, which is between at least three axially aligned steel knobs embossing rollers, optionally knurled wheels, optionally wide knurled wheels (26) and one or more of these knobs Embossing rollers, if appropriate knurling wheels, if appropriate mating roller (s) associated with wide knurling wheels, preferably with a rubber surface, plastic surface, Paper surface or steel surface (27) is formed, and that the multilayered tissue product web thus formed is divided by cuts into several narrower tissue product webs after the layers have been stitched together in the embossing gap, which cuts each lead approximately in the middle of the strip-shaped embossing patterns formed in this stitching the division into several narrower tissue product webs, which have the width desired for the use of the tissue product, is carried out after the roll-up of the tissue product web which has passed through the embossing nip has been rolled up.

22. The method according to claim 21, characterized in that strip-shaped embossing patterns are formed each 10 to 80 mm, preferably 20 mm to 60 mm wide, when the tissue webs are stitched together.

23. The method according to claim 21 or 22, characterized in that the knob embossing roller (26) on at least part of their surface (30) have depressions (31) which produce a further connection stamping.

24. The method according to claim 23, characterized in that the further connection embossing is carried out by depressions (31) in the form of a plurality of polygons or circles, preferably rectangles or parallelograms.

25. The method according to the preceding claims, characterized in that subsequent to the further embossing, smoothing takes place by means of a soft smoothing unit, in which the tissue product web is guided through one or more columns, with several columns lying one behind the other, first one A roller with a steel surface is associated with a counter roller with a plastic surface and then a roller with a plastic surface is mirror-image-associated with a counter roller with a steel surface. 43

26. Device for the production of tissue products according to claims 1 to 13, containing means for unwinding mother rolls (21, 22, 23) and guiding and regulating the web tension of the tissue webs (18, 19, 20), an embossing station (24) for the tissue webs (18, 20), a further embossing station (25) which forms an embossing gap in which a plurality of narrow embossing rollers are optionally assigned knurling or wide knurling wheels (26) to a counter roller (27), if appropriate a smoothing unit, possibly a printing unit and a reeling station (28).

27. The device according to claim 26, characterized in that the first embossing station (24) contains at least one pair of rollers in which a roller with a steel surface is associated with a roller with a rubber surface, plastic surface or steel surface.

28. Device according to claim 26 or 27, characterized in that the first embossing station is used exclusively for embossing the outer layers (18, 20).

29. Device according to claim 26 to 28, characterized in that the further embossing station (25) contains a knurling station in which a knurling wheel roller or a plurality of knurling wheels is assigned at least one counter roller (27) with a steel surface, rubber surface, plastic surface or paper surface.

30. Device according to claim 26 to 29, characterized in that the knurled wheel roller has knurled wheels which produce knurling over 10 mm to 80 mm, preferably over 20 to 60 mm.

31. The device according to claim 26 to 30, characterized in that the knobs of the knurled wheels have depressions (31) on at least part of their surface. SO

Device according to claims 26 to 31, characterized in that means for regulating the tensile stress and the speed of each individual tissue layer, in particular the outer layers, are provided with respect to the middle layer (s)

Device according to claims 26 to 32, characterized in that the recesses (31) are designed as a plurality of polygons or circles, preferably rectangles or parallelograms

Device according to claims 26 to 33, characterized in that means for spreading each of the tissue web (s) and the tissue product web are provided