EP0178294B1 - Device and process for making finished skiver - Google Patents

Abstract

A leather, in particular a skiver, has depressions on at least one side and also absorbent, protruding fibres on that side. This side is bonded to a layer (14, 14a) which has been formed from an aqueous polymer dispersion and which fills out the depressions and completely absorbs the protruding fibres of the leather (13). This layer (14, 14a) forms either the entire surface finish or, in a two-layered structure thereof, the inner layer (14a) thereof. In this case, the inner layer (14a) has on top of it an outer layer (14b) which has been formed from an aqueous polymer dispersion or from a liquid polymer solution and which has been provided with a textured surface (16). <??>Such a surface finished leather is made by applying to the leather, to form the surface finish (14), an aqueous polymer dispersion in an amount between 150 g/m<2> and 450 g/m<2> in the wet phase, then placing the leather with the surface finished side facing down onto a base (2, 2') having a textured surface, and finally press bonding the leather to the applied polymer dispersion and subjecting it to a vacuum treatment. If the surface finish is to have a two-layer structure, then, before the leather with the aqueous polymer dispersion is placed on the textured surface of the base (2, 2'), the latter has applied to it a further aqueous polymer dispersion or liquid polymer solution, and the leather is placed on top of the base only after this further aqueous polymer dispersion or liquid polymer solution has solidified. <IMAGE>

Description

The invention relates to a method for dressing split leather or leather fiber materials, and a device for producing a finish on split leather or the like.

It is already known to provide split leather with a finish which has a structured surface, for example a surface structured like a leather grain. Here, a liquid, wet, the dressing-forming mass is applied directly to the top of the split leather, for example by pouring, brushing, plushing, spraying, printing, or by means of a roller application machine and solidifying by drying. In order for the finish to be given a leather-grain-like structured surface, the finished split leather must be embossed in this known method after the liquid dressing composition has dried or after the finish has solidified. This split leather is embossed in an embossing press under the action of heat at very high pressure. This undesirably changes the structure of the split leather and the finish. The trimmed split leather not only becomes thinner, but also harder and stiffer. Furthermore, the existing water vapor permeability of the dressing is reduced or destroyed because the pores present in the dressing are closed or destroyed again during embossing under heat and pressure.

A major disadvantage of this known method is that only thermoplastic materials which can be deformed under heat and pressure can be used for the preparation of the dressing, since otherwise it is not possible to subsequently emboss the structured surface into the hardened dressing. However, such thermoplastics have poorer properties than non-thermoplastic or less thermoplastic.

Another disadvantage is that the embossing of the structured surface takes place in a separate work process, i.e. the finished split leather must be treated further, that is, as a rule, inserted manually into an embossing press.

From EP-A 105 046 it is also known not to apply the liquid dressing compound directly to the split leather, but rather to apply this liquid dressing compound in several layers to a support provided with a non-stick coating and a surface corresponding to the desired structuring, the split leather being applied the last layer is laid in its wet phase and the split leather thus prepared is then pressed in a roller press and / or subjected to a vacuum treatment. With this procedure, an undesired hardening or hardening and an undesirable reduction in the thickness of the split leather is largely avoided, but the connection between the finish and the split leather is worse.

In EP-A 105 046 it is already proposed to first apply a part of the dressing compound to a base and allow it to solidify, then to apply another part of the dressing compound to one side of the split leather and this with the applied dressing compound in its wet phase on the base hang up in such a way that the side of the split leather provided with the finish lies on the solidified finish on the base and the dry side of the split leather without the finish points upwards. The base hiebei has a negative shape corresponding to the desired leather grain-like structured surface of the dressing, so that when the dressing composition dries under light pressure, the dressing at the same time acquires a leather grain-like appearance. In this procedure, the dressing is structured in such a way that the split leather does not change its thickness, softness and water vapor permeability, or changes it only slightly. Prepared split leather produced in this way is therefore soft, supple and comes closest to the full-grain leather in terms of its appearance and properties. The main disadvantage of this known procedure is, however, that the split leather must be turned over immediately after the wet dressing compound has been applied, so that the side of the split leather provided with the dressing compound faces downward and in the wet state with the base having a corresponding structure is brought into full contact. In particular with large gaps, manual turning over creates considerable difficulties and is associated with great physical exertion. In addition, during manual turning and laying on the pad, there are often air pockets between the pad and the side of the split leather provided with the finish, which deteriorates the adhesion of the finish and the appearance of the finish provided with the leather-like structure in the places where the Air pockets are present, is significantly impaired. This appearance is also adversely affected by the fact that the still wet dressing is damaged by touching the split leather for manual reversal, and in that if the split leather is not placed in the correct position on the base, a subsequent shifting is necessary.

The present invention has for its object to provide a finished split leather or a leather fiber material in which the finish having a structured surface can be made very thin, so that the properties of the split leather or the like are not significantly changed by applying the finish , whereby the coarse fibrous structure of the split leather is not on the surface of the finish and an inseparable connection between the leather and the finish is guaranteed.

Therefore, the present invention is intended to create a method and a device by means of which the preparation of such prepared split leather or the like is made possible in a simple and safe manner. In particular, the work involved in carrying out a color change during dressing should also be reduced.

To achieve this object, the method and the device according to claims 1 and 17 are proposed according to the invention. The fact that the layer formed by the aqueous plastic dispersion fills the recesses of the leather and completely surrounds the protruding fibers of the leather not only ensures an absolutely inseparable connection between this layer and the leather, but also ensures that the surface of the dressing only the desired has a structured shape, but the depressions of the leather and the fibers protruding from this leather do not appear on this surface of the dressing.

The term “aqueous plastic dispersion” is understood to mean highly polymeric plastics which contain water or are dispersed in water and which form films by removing the water, for example by evaporation, preferably with the addition of heat.

The dressing consists of two layers, the inner layer adjacent to the leather and completely absorbing the projecting fibers being formed by the aqueous plastic dispersion and the outer layer having the structured surface being formed from an aqueous plastic dispersion or from a liquid plastic solution.

The term “liquid plastic solution” is understood to mean high-polymer plastics dissolved in a solvent, which when sprayed or brushed form films which solidify through solvent removal, for example through evaporation of the solvent.

Such a design enables the plastic dispersion or plastic solution forming the dressing to be more rapidly solidified by evaporation of the water or solvent, since the thickness of each of these layers can then be kept thinner and the first layer already solidifies before the second layer is formed. Above all, however, this design makes it possible to produce the structured visible surface of the dressing separately by arranging the outer layer and to adapt it to the respective requirements, whereas the inner layer, which fills the depressions of the leather and accommodates the fibers protruding from the leather, can be left unchanged.

By applying the plastic dispersion in the specified amount, a finish is made with a thickness such that, on the one hand, a good, inseparable connection with the leather takes place, whereby a complete embedding of the fibers protruding from the leather is guaranteed, and on the other hand the properties of the leather through the finish are not be adversely affected.

So that the layer adjacent to the leather and its protruding fibers completely absorbing the desired foam structure, these hollow microspheres with a diameter of 0.008 to 0.1 mm are expediently admixed with the thin shell of thermoplastic material, preferably of vinylidene chloride, before application of the aqueous plastic dispersion Copolymer, exists.

According to the invention, before the leather provided with an aqueous plastic dispersion is placed on the structured surface of the base, an aqueous plastic dispersion or a liquid plastic solution is applied to it, the leather being applied to the base only after this further aqueous plastic dispersion or liquid plastic solution has solidified . This further aqueous plastic dispersion or liquid plastic solution can then, for example, directly form a finish. The construction of the dressing from two layers, of which the layer adjacent to the leather is preferably thicker than the layer with the structured surface, gives the advantage that the dressing has better abrasion properties than a dressing formed from a single layer.

The solidification of the layers forming the dressing can be accelerated by heating the aqueous plastic dispersion or liquid plastic solution during and / or after application, so that the water or solvent escapes more quickly. Such heating can be done electrically, for example by infrared radiation, but also by a gas burner. The aqueous plastic dispersion or liquid plastic solution applied to the surface of the base solidifies, starting from the heated base, so that there are no bubbles in the area forming the dressing, since there immediately upon contact of the aqueous plastic dispersion or liquid Plastic solution forms a firm skin with the heated surface.

It is particularly expedient if the aqueous plastic dispersion is applied to the leather by means of at least one application roller. The leather is expediently moved past the application roller, the direction of rotation of the application roller being opposite to the direction of movement of the leather. This ensures that the fibers protruding from the leather are fully embedded in the layer applied in a single operation using the shear forces and are thus inseparably connected to this layer after solidification.

A liquid plastic loaf is advisable solution or an aqueous plastic dispersion used that contains more than 40 vol .-% solids. It is advantageous if, in particular, the aqueous plastic dispersion or liquid plastic solution applied to the base contains pigments and / or dyes, which then determine the color of the finish. A crosslinkable, essentially non-thermoplastic polyurethane and / or polybutadiene dispersion is preferably used.

In particular, if the base consists of a silicone plate, it is advantageous if, according to the invention, the aqueous plastic dispersion is poured or sprayed onto the base. By pouring or spraying a thin layer onto the heated and therefore more than 70 ° hot surface, micropores are also formed in the desired manner, because the solidification of the poured or sprayed-on dispersion begins as soon as it hits the heated surface.

However, the base can also consist of a paper provided with an appropriate structuring, which is expediently provided with a coating. In this case it is advantageous to apply the liquid plastic solution to the base using a doctor blade.

The aqueous plastic dispersion forming the outer layer, which is applied to the base by casting or spraying, expediently has a lower viscosity and the liquid plastic solution applied to the base by doctor blade has a higher viscosity than the dispersion applied to the leather, which embeds the inner fibers Layer forms.

It is particularly advantageous if the leather is further moved with the finishing during the vacuum treatment. Since the application of the aqueous plastic dispersion to the leather, the application of the aqueous plastic dispersion or liquid plastic solution to the base and the placement of the leather provided with the aqueous plastic dispersion on the base as well as the pressing can be carried out continuously in this case, if so Leather with the finishing during the vacuum treatment is moved, enables a continuous production of the finished leather in the assembly line process.

The device according to the invention for the production of finished leather, in particular finished split leather, is provided with a support for the finished leather, a device for applying the dressing in the liquid phase to the leather to be finished and a device for producing a structure in the dressing, and essentially characterized in that at least part of the support is movably guided around a deflection point, in the area in which the leather provided with the dressing is transferred to a base which can be moved at essentially the same speed as the support in such a way that the leather with the The side provided for the preparation rests on the base, and the base is provided with a structured surface, for example with a negative leather grain structure. The device according to the invention enables the leather provided with an at least partially liquid dressing to be turned over in a simple manner without manual actuation, so that it then rests with the side provided with the dressing on the base at the bottom. When using the device according to the invention, the advantage is achieved in particular that the adhesion of the dressing composition to the leather is improved in that the dressing in the liquid phase is applied directly or immediately to the leather, so that the dressing is inseparably connected to the leather However, the disadvantages that arise when the leather is manually turned over with the wet dressing are avoided. The finished dressing thus does not have any disturbing errors which result from touching the leather provided with the wet dressing or by subsequently moving the leather which has already been turned over and deposited. By using the device according to the invention, the time which elapses between the application of the liquid dressing and the storage of the leather provided with the liquid dressing is reduced and, above all, can be calculated precisely in advance. As a result, the underlay can be warmed to a greater extent and the drying process of the dressing proceeds more quickly. Furthermore, the dressing compound can be applied to the leather in a thinner layer, because the fact that the time between the application of the liquid dressing and the turning and laying down of the leather on the pad can be kept very short ensures that none or at least almost no liquid evaporates or emigrates to the leather, which means that the finish adheres very well to very absorbent areas of the leather.

The use of the device according to the invention also makes it possible to bond porous, air and water vapor permeable dressings with a density of less than 0.8 firmly and inseparably to the leather, in particular split leather, which are particularly suitable for the production of shoe uppers which be provided with a foamed-on polyurethane sole, because the shoe upper made of split leather according to the invention and inserted into the shape required to form the polyurethane sole enables the air to escape during the foaming process due to the porous formation of the dressing. In addition, there is an excellent mechanical anchoring of the polyurethane sole during the foaming process with the upper of the shoe, since the polyurethane penetrates into the porous finish, so that an excellent connection between the finished split leather and the polyurethane sole is ensured.

When using the invention direction, the leather, which is already in a liquid phase, can be transferred to the support and from there to the base. However, the dressing can also be applied to the leather if it lies on the support.

The support can consist of an endless, driven belt guided over at least two rollers, one of the rollers forming the deflection point. This enables a continuous operation, whereby the liquid finish can be applied to the leather as it moves forward with the belt. The support forming the band expediently consists of rubber or plastic, that is to say of a material to which the leather adheres, so that it does not slip off the support, but in the transfer area detaches from the support and is transferred to the base. The band forming the support can also be provided with a cover, for example made of paper, wherein the paper can consist of an endless paper web in order to prevent contamination of the band when the aqueous plastic dispersion is applied to the leather located on the support. This paper can then be transferred to the base together with the leather, where, since the leather is turned onto the base when it is transferred, it forms the top layer. In particular, if the paper is air-permeable, it does not interfere with the further processing of the leather provided with the dressing and also protects the subsequent processing devices against contamination.

In order to easily apply the aqueous plastic dispersion to the leather in one operation, an application roller is provided according to the invention above the support, the direction of rotation of the application roller preferably being opposite to the direction of movement of the support. If this applicator roller rotates in the opposite direction to the movement of the support and thus also to the movement of the leather, then the aqueous plastic dispersion is massaged into the leather, resulting in an intimate connection with the leather. The arrangement of such a counter-rotating applicator roller is particularly advantageous if an aqueous plastic dispersion is applied, to which hollow microspheres are added in the manner mentioned, since in this case the hollow microspheres are also massaged into the leather and arranged between the fibers and contribute to this that the trimmed split leather has no uneven surface even when stretched. It is also advantageous if the layer applied to the leather, consisting of the aqueous plastic dispersion provided with hollow microspheres, does not contain any pigments or dyes, since in this case it is ensured that these pigments, which often have sharp edges and therefore have shielding properties, Dyes do not destroy the thin shells of the hollow microspheres when applied.

According to the invention, the base can be formed by a moving conveyor belt. The support is expediently formed by an endless conveyor belt which is guided by guide members, for example rollers. However, it is also possible to form the base from a plate-shaped carrier body which can be moved by means of a transport device, for example transport rollers. This design has the advantage that the finished leather can be transported away together with the carrier body, for example for further processing of the leather.

The base is preferably heated, as a result of which the solidification of the liquid dressing is accelerated and the advantages already mentioned occur.

The underlay expediently consists of silicone rubber, which is preferably provided with a reinforcement. For example, a wire mesh can be used as reinforcement. However, the reinforcement preferably consists of a fleece or fabric made of glass, asbestos or carbon fibers. These materials have the advantage that they are light in weight and have almost no thermal expansion and that they can withstand the temperatures that occur as well as the silicone itself.

The reinforcement can be embedded in the base, but can also be attached to the underside of the base.

It is also advantageous if the base consists of two layers with different hardness and / or different elasticity, the lower layer being harder and / or less elastic than the upper layer.

If the base consists of silicone rubber, then the surface on which the finished leather is placed has a structured surface which gives the top of the finish a leather-like appearance.

The base can also be formed from a structured paper, preferably provided with a plastic coating, in particular from a roll of paper that can be pulled off, to which a thin film of the aqueous plastic dispersion or liquid plastic solution is applied in the case of a two-layer structure of the dressing. This aqueous plastic dispersion or liquid plastic solution is expediently applied by means of a pouring, doctoring or spraying device provided above the base.

In order to improve the adhesion of the dressing to the leather, according to a further feature of the invention, a pressing or pressing device is provided which acts on the base supporting the leather provided with the dressing.

To facilitate the transfer of the leather with the liquid finish from the support to the base, inventions can be made According to the invention, at least one transfer roller can be provided in the transfer area from the support to the base. Such transfer rollers are particularly useful when the support is formed by a circumferential belt and the diameter of the rollers over which this belt is guided is large. Multiple transfer rollers of smaller diameters can also be used.

The device according to the invention furthermore has a drying device, preferably formed by a vacuum device, for the leather provided with the dressing on the base, which causes the dressing to rapidly solidify and remove the vapors produced during this hardening. According to a preferred embodiment of the invention, the vacuum device consists of at least two moving parts, between which the leather provided with the finish is arranged, at least one of these parts having elastomeric properties and being provided with at least one closable opening which can be connected to a vacuum source , as a result of which a negative pressure can be maintained between the two parts, which causes the part having the elastomeric properties to be pressed against the leather provided with the finish and supported on the other part. By moving the two parts while maintaining the vacuum between the two parts, a continuous manufacture of the trimmed leather can be achieved because the speed of movement of these two parts constituting the vacuum device can easily be based on the movement of those in front of this vacuum device Facilities, in particular to the speed of movement of the pad. The lower of these two parts is expediently formed at least in part by the base, which is supported on a transport device, so that the vacuum treatment of the finished leather takes place on the base on which the leather was deposited when the finish was formed. This also supports continuous production.

The transport device can consist, for example, of individual moving tables on which the support rests. These tables expediently move in a closed path, for example in a substantially circular path, so that after a certain time each table comes back to a transition point where a pad provided with a trimmed leather is handed over.

However, the transport device can also be formed by an endless rotating carrier body. This carrier body expediently consists of individual, interconnected plate-shaped or tubular elements which, according to a further feature of the invention, are interconnected by at least one transport chain which is guided around sprockets. The formation of the carrier body from individual, interconnected plate-shaped or tubular elements has the advantage over the formation of the carrier body as an endless belt that thermal expansion can be compensated for by changing the gaps between the elements.

According to the invention, the plate-shaped or tubular elements can consist of metal, preferably of steel, but also of heat-resistant plastic, for example of polyimide or of silicone rubber, in the latter case preferably a reinforcement of metal, for example of a wire mat, of a fabric or of a fleece is provided so that the elements are able to withstand the stress that occurs.

However, the carrier body can also consist of an endless band, for example of a steel band or of a band of elastomeric material, for example of silicone rubber.

In order to prevent the carrier body from moving downward when the vacuum is applied and the upper part is thereby pressed onto the support supported on the carrier body, support rollers can be provided according to a further feature of the invention below the carrier body.

Furthermore, heating devices, for example infrared emitters, are expediently provided below the printing device or the carrier body, by means of which the underlay and the finished leather supported on the underlay are heated. This heating causes the dressing to solidify more quickly.

According to a preferred embodiment of the invention, the upper of the two moving parts has a membrane made of elastomeric material which, when a negative pressure is formed between the two parts, is pressed against the leather provided with the dressing on the lower part. The membrane can have an all-round sealing strip, which is supported on the transport device or on the support supported on it, the membrane being moved by the transport device. The membrane can interact with a single piece of leather, but also with two or more pieces of leather arranged side by side. A plurality of membranes can also be arranged next to one another on the transport device, one of these membranes in each case covering at least one finished leather, the membranes possibly being connected to one another.

In a further embodiment of the invention, the membrane is formed by a band consisting of an elastomeric material, which moves synchronously with the endless, rotating support body. In particular, if this band consists of a semi-hard material and has a thickness of at least 2 mm, it attaches to the split leather due to its own weight, which already results in a certain amount Sealing takes place between the membrane and the base or the transport device, which enables the formation of a vacuum when connected to a vacuum source. However, in order to ensure such a seal, the band consisting of elastomeric material and / or the carrier body can be provided with sealing strips made of elastomeric material at the edge regions running in the direction of movement and optionally at predetermined intervals transversely to the direction of movement. These sealing strips are preferably made of a softer material than the membrane and can be glued or vulcanized to the membrane or, if the carrier body consists of plastic, to this carrier body.

The openings for connection to the vacuum source are expediently arranged in the sealing strips and provided with valves. The arrangement of the valves has the advantage that the connection to the vacuum source can be interrupted during the further movement of the transport device and the membrane and the vacuum can still be maintained by closing the valve.

So that the vapors produced during the drying of the dressing are also safely removed from the inner areas of the leather, according to the invention the membrane on the side facing the leather is provided with grooves which form channels for the removal of these vapors.

Preferably, the membrane is also heated, whereby the advantage is achieved that the plastic material forming the finish, if it should settle on the membrane in an undesirable manner when it emerges from the side of the leather, can solidify there and then be easily removed.

According to a preferred embodiment of the invention, the transfer area from the support to the base is provided between the pouring, knife or spray device for applying the plastic dispersion or plastic solution to the base and the vacuum device. In this way, rational production by means of the device according to the invention is made possible.

According to the invention, the base can be arranged below the application roller. The structure of such a device is simple, but when using known application devices on the market, the space required is often not available there. In this case, an embodiment is advantageous in which the base is arranged on the side of the application roller. The support is then expediently formed according to the invention by an arc-shaped deflection device, for example consisting of transport rollers, which is arranged between a conveyor belt or the like which conveys the leather to be finished and which interacts with the application roller and the base and which causes a change in the direction of movement of the leather. The deflection device can be designed in such a way that the leather is deflected in a direction in which it can be transferred to a base which is guided past the device for applying the dressing.

In order to facilitate the detachment of the leather from the support and the transfer to the base, a compressed air nozzle directed towards the leather located on the support can be provided in the transfer area. The compressed air emerging from this nozzle releases the leather from the support.

Finally, the speed of the support and the support can be regulated, preferably continuously, whereby the time between the application of the liquid dressing to the leather and the placement of the leather provided with the dressing on the support changes and the respective requirements according to the amount of applied Dressing, the temperature of the edition, etc., can be adjusted.

The invention enables the production of a finished split leather or leather fiber material, in which the finish, despite the fact that it only consists of a relatively thin layer, has a deceptively similar surface to a full-grain leather or a velor-looking leather and also has the outstanding properties of such leather, whereby an absolutely inseparable connection between the split leather or the like and the dressing is guaranteed. In particular, the finished leather according to the invention has the desired water vapor permeability and there is no stretching when stretching due to the foam structure of the dressing, which is caused not least by the use of the vacuum device and by the inclusion of hollow microspheres in the dressing. The device according to the invention enables in a particularly advantageous manner a continuous production of the finished leather, this continuous production also being ensured in the vacuum device, since this continues to move while the negative pressure is maintained and is only opened when the dressing has completely solidified and the process for the preparation of the finish has ended.

• Fig. 1 in Seitenansicht eine erste Ausführungsform der erfindungsgemäßen Vorrichtung;
• Fig. 2 in Seitenansicht eine zweite Ausführungsform der erfindungsgemäßen Vorrichtung;
• Fig. 3 eine abgewandelte Ausführungsform nach Fig. 1;
• Fig. 4 ein Detail der Ausführungsform nach Fig. 3 in größerem Maßstab;
• Fig. 5 in vergrößertem Maßstab ein erfindungsgemaßes Spaltleder mit einer aus zwei Schichten gebildeten Zurichtung;
• Fig. 6 in Draufsicht eine dritte Ausführungsform der erfindungsgemäßen Vorrichtung;
• Fig. 7 zeigt schematisch in Draufsicht eine erfindungsgemäße Vorrichtung, die ein Arbeiten im Fließbandverfahren ermöglicht;
• Fig. 8 zeigt in Draufsicht eine erste Ausführungsform einer Vakuumvorrichtung, die einen Teil der erfindungsgemäßen Vorrichtung bildet;
• Fig. 9 stellt einen Schnitt nach der Linie X-X in Fig. 8 dar;
• Fig. 10 zeigt in Seitenansicht eine zweite Ausführungsform der Vakuumvorrichtung;
• Fig. 11 stellt einen Schnitt nach der Linie XII--XII in Fig. 10 dar;
• Fig. 12 zeigt in Seitenansicht eine dritte Ausführungsform einer Vakuumvorrichtung.

In the drawing, the invention is illustrated schematically using exemplary embodiments. Show it:

• 1 shows a side view of a first embodiment of the device according to the invention;
• 2 shows a side view of a second embodiment of the device according to the invention;
• 3 shows a modified embodiment according to FIG. 1;
• 4 shows a detail of the embodiment according to FIG. 3 on a larger scale;
• 5 shows on an enlarged scale an inventive split leather with a dressing formed from two layers;
• 6 is a top view of a third embodiment of the device according to the invention;
• Fig. 7 shows schematically in plan view a device according to the invention, which enables working in the assembly line process;
• 8 shows a top view of a first embodiment of a vacuum device which forms part of the device according to the invention;
• Fig. 9 shows a section along the line XX in Fig. 8;
• 10 shows a side view of a second embodiment of the vacuum device;
• Fig. 11 shows a section along the line XII - XII in Fig. 10;
• 12 shows a third embodiment of a vacuum device in side view.

The device shown in FIG. 1 has a support 1 for the leather to be finished, formed by a split leather 3, which is formed by an endless driven belt which is guided over two rollers 5. The split leather 3 is placed on the belt 1 and the dressing 4, which consists of an aqueous plastic dispersion, is evenly applied to the split leather 3 via an application roller 6 while the latter is moving under the application roller 6. The applicator roller 6 rotates, as indicated by the arrows, in the opposite direction to the direction of movement of the belt forming the support 1.

Instead of the application roller 6 rotating in opposite directions, a pouring device can also be used, by means of which the dressing 4 consisting of an aqueous plastic dispersion is applied to the split leather 3 while the latter is moving on. In this case, the support 1 does not consist of an endless driven belt, but rather of endless ropes guided over the two rollers 5, which gives the possibility that the excess aqueous plastic dispersion can flow off.

The lower roller 5 forms a deflection point for the belt 1, at which the split leather provided with the liquid dressing is lifted off the belt 1 and placed on a base 2 formed by a conveyor belt such that the side of the split leather 3 provided with the liquid dressing 4 rests on this conveyor belt 2. The conveyor belt 2 moves at the same speed as the belt 1, so that when the split leather 3 provided with the finish is transferred to the conveyor belt 2, there is no relative displacement between the split leather 3 and the conveyor belt 2.

A counter roller 7 supporting the conveyor belt 2 is provided below the lower roller 5 so that the conveyor belt 2 does not sag in the transfer area. This conveyor belt 2 is guided over rollers 8.

The detachment of the split leather 3 provided with the dressing 4 from the belt 1 and the transfer of this split leather to the conveyor belt 2 can be facilitated in that a compressed air nozzle 19 is provided in the transfer area, the compressed air emerging from this nozzle blowing against the split leather 3 and this detaches from conveyor belt 1.

The conveyor belt 2 is preferably made of silicone rubber, the upper side of the conveyor belt 2 having a negative grain structure, so that the dressing that is solidifying on the conveyor belt 2 is provided with a grain structure on its surface and therefore has a leather-like appearance. In order to accelerate the film formation of the dressing, the conveyor belt 2 is heated in a manner not known per se, which is known per se.

The embodiment according to FIG. 2 differs from the embodiment according to FIG. 1 in that, instead of the conveyor belt 2, a base 2 'formed by a plate-shaped carrier body is arranged, which is moved forward by means of transport rollers 9. The plate-shaped carrier body is preferably made of silicone rubber and is provided with a reinforcing insert made of nonwoven or fabric made of glass or carbon fibers. The base 2 'can also be constructed from two layers, the upper layer having the structuring being softer or more elastic than the lower layer. Furthermore, a transfer roller 10 is provided in the transfer area, via which the split leather 3 provided with the dressing 4 is transferred to the plate-shaped carrier body 2 '. This plate-shaped carrier body 2 'is also heated.

Instead of the transfer roller 10, a transfer belt can also be provided, by means of which a change in the position of the split leather can be effected during transfer to the plate-shaped carrier body 2 '.

The plate-shaped carrier body 2 'can either itself have a negative grain structure, so that the surface of the dressing solidifying on this carrier body is provided with a grain structure, but it is also possible to have a structured surface with a plastic coating on the plate-shaped carrier body put on provided paper, which causes the formation of a structured surface of the dressing. Of course, such a structured surface paper can also be placed on the conveyor belt 2 (FIG. 1), which then has no negative scar structure and which, for example, consists of a paper web that can be pulled off a roll.

In the embodiment according to FIG. 3, pressure or pressure rollers 11, 11 'are provided, by means of which the split leather 3 provided with the dressing 4 which is in the solidifying state is pressed against the top side of the conveyor belt 2 provided with the grain structure. From Fig. 3 it can also be seen that the conveyor belt 2 does not have to run flat over its entire length, but can be bent in the area of the counter-roller 7, as is shown in broken lines in Fig. 3. Such a design facilitates the transfer of the split leather 3 provided with the finish 4 from the belt 1 to the conveyor belt 2.

Also in the embodiments according to FIGS. 2 and 3, compressed air nozzles causing the split leather to be detached can be provided.

FIG. 4 shows the application of a layer 12 to the conveyor belt 2, as is necessary in the case of a two-layer construction of the dressing. Such a layer can of course also be applied to a plate-shaped support body 2 'forming the base or to the paper web. This layer 12, which is formed from an aqueous plastic dispersion or from a liquid plastic solution, is applied by means of a casting, knife or spray device 20. The layer 4 of an aqueous plastic dispersion applied to the split leather 3 then forms the inner layer of the dressing. In this case, the split leather 3 provided with the still liquid layer 4 is placed on the base 2 or 2 'only after the layer 12 has at least largely solidified. In order for this to be the case, the doctor blade or spray device, via which the layer 12 is applied to the base 2 or 2 ', is located on one side of this transfer region at a distance from the transfer area from the conveyor belt 1 to the base 2, 2'. On the opposite side of this transfer area, a drying device (not shown), for example a vacuum dryer, is provided for the split leather 3 provided with the finish.

The speed of the belt 1 and the base 2 or 2 'is expediently infinitely variable in order to be able to adapt it to the respective requirements. The preferred speed at which the split leather 3 moves forward is between 3 and 8 m / min.

6 shows a top view of a device according to the invention, in which the support consists of an arcuate deflection device which is formed by a plurality of transport rollers 1 '. In this device, a known device for applying the dressing in the liquid phase to the split leather is used, which consists of a conveyor belt 18, over which the split leather is moved, whereby the dressing 6 is applied evenly to the split leather 3. At the end of the conveyor belt 18 opposite the applicator roller 6, the at least partially driven conveyor rollers 1 'are connected, which are arranged in such a way that the split leather 3 transferred from the conveyor belt 18 to these conveyor rollers 1' is deflected by approximately 90 °. The last of these transport rollers 1 'forms the deflection point 5, at which the split leather provided with the liquid dressing 4 is placed on the base formed by a transport belt 2 such that the side of the split leather provided with the liquid dressing 4 rests on this transport belt 2. Of course, in this embodiment too, instead of the conveyor belt 2, a base 2 'formed by a plate-shaped carrier body can be provided, which is moved forward in a manner analogous to the embodiment according to FIG. 2 via transport rollers. In any case, the deflection device ensures that the conveyor belt 2 or the support 2 'moved forward via transport rollers can be arranged in a position in which the device for applying the dressing to the split leather is not in the way.

FIG. 7 schematically represents a continuous workflow when dressing a split leather. On a conveyor belt 21, which replaces the transport rollers 9 in FIG. 2, the pads 2 'made of silicone rubber are moved further in the direction of the arrow 22. The top of the documents 2 'is provided with a structure. An aqueous plastic dispersion or a liquid plastic solution is poured or sprayed onto this upper side by means of the device 20 and allowed to solidify during further movement, the solidification being accelerated by heating devices, not shown, by means of which the underlays 2 'are heated.

The conveyor belt 1, on which the split leather 3 rests, is located at a distance from the device 20. An aqueous plastic dispersion is applied to the split leather via the applicator roller 6 in the manner described, and then the split leather is placed with the wet side at the bottom on a base 2 'provided with the already solidified layer, as previously discussed.

The split leather thus prepared is deflected via transport rollers 21 'and arrives at a further conveyor belt 23, where the split leather is pressed onto the base 2' by means of the press rolls 11. After a further deflection via transport rollers 23 ', the finished split leather reaches a vacuum device 24, which is described in more detail below, and from there via transport rollers 25' onto the conveyor belt 25, where at 26 the finished split leather provided with a finish is removed . The documents 2 'are conveyed onward and reach the conveyor belt 21 again via transport rollers 27'.

8 and 9, a first embodiment of a vacuum device is shown. Tables 29 are attached to a support part 28 which can be rotated about an axis 28 'and which form a support body for the base 2'. At point 33, a table 29 is loaded with a base 2 'on which a prepared split leather is located. This is followed by a further movement of the tables 29 in the direction of the arrow 34. In the next position, a membrane 30 is placed on the table 29, which can be rectangular, in particular square, but also round, in particular circular, and which has an all-round on its edge Has sealing strip 31, whose free end, preferably provided with a profile, rests on the table 29. The membrane 30 provided with the sealing strips 31 thus surrounds the base 2 ′ with the trimmed split leather 3.

An arranged at one point of the sealing strip, provided with a valve, is connected to a vacuum source, not shown, so that after connecting this vacuum source in the space enclosed by the membrane 30 and the sealing strip 31, a negative pressure is created, which causes the membrane 30 lies against the split leather 3 and presses it against the base 2, at the same time sucking off the vapors produced during the drying of the dressing.

Both the membrane 30 and the sealing strip 31 are made of an elastomeric material, the sealing strip 31 preferably being made of a softer material than the membrane 30. Rubber or rubber, in particular silicone rubber, are primarily suitable as the elastomeric material.

If the valve of the opening 32 is closed, the negative pressure is maintained even if the connection to the vacuum source is interrupted. The table 29 is then moved together with the base 2 'and the membrane 30 pressed against the split leather 3 into the position shown on the right in FIG. 8 and finally arrives at the removal point 35, where the valve of the opening 32 is opened, so that a Connection of the space enclosed by the membrane 30 and the sealing strips 31 to the atmosphere takes place. As a result of the material's own restoring force, the membrane 30 returns to the starting position and can be lifted off, the trimmed split leather is removed together with the base 2 '.

In the embodiment according to FIGS. 10 and 11, a carrier body consisting of plates 36 is provided, the plates being connected via projecting projections 37 to transport chains 38 which are guided via chain wheels 39. Instead of the plates, lamellae or tubular support bodies can also be provided.

The plates 2 ′ rest on the plates 36, on which the split leather 3 provided with the finish is located. The documents 2 'are expediently arranged so that they each cover a gap between two adjacent plates 36.

Below the plates 36 there are heating devices, for example infrared radiators 40, by means of which the plates 36 and thus also the documents 2 'are heated.

The plates 36 cooperate with a membrane 41 consisting of an endless band, which band is guided over rollers 42. This membrane 41 formed from the endless band is designed in such a way that a tight seal between the membrane and the underlays 2 'or the plates 36 is possible, so that a negative pressure can again be formed in the intermediate space. For this purpose, in the embodiment shown in FIG. 10, sealing strips 43 made of an elastomeric material are provided on the edge regions of the membrane 41 running in the direction of movement, and sealing strips 44 also running, if appropriate, transverse to the direction of movement Sealing strips can be built. In the sealing strips or in the absence of the same in the membrane 41, openings 45 are provided with a valve, which can be connected to a vacuum source. As a result, the membrane 41 is again pressed against the split leather 3 located on the base 2 'and the fumes produced when the dressing dries are extracted.

The endless band forming the membrane 41 is shorter than the support body formed by the plates 36 and acting like an endless band, so that the finished split leather 3 can be removed in a simple manner together with the base 2 '.

The suction of the vapors is improved in that grooves 41a are provided on the side of the membrane 3 facing the leather 3, through which grooves the vapors which are formed can escape. Such grooves can of course also be provided in the membrane 30 (FIGS. 8 and 9).

The plates 36 are preferably made of metal, for example steel. The arrangement of individual plates instead of an endless steel strip has the advantage that the thermal expansion of the plates does not have a disruptive effect due to the subdivision. In particular when using substrates 2 'made of silicone, the gap between adjacent plates 36 is sealed in such a way that this gap does not hinder the formation of the vacuum. This vacuum is formed in this case between the base 2 'made of silicone rubber and the membrane 41 and, if present, the sealing strips 43, 44, the sealing strips 44 dividing the membrane 41 into a plurality of chambers.

The membrane 41 consisting of an endless band expediently consists of rubber or caoutchouc and can be reinforced by a metal grid, a fabric or a fleece. The reinforcement can either be arranged as an insert within the membrane or be placed on the outside of the membrane.

As a rule, the dead weight of the membrane 41 is sufficient to ensure an initial seal against the base 2 ', which subsequently enables the vacuum to be formed. However, pressure rollers 42 'can also be provided, by means of which the membrane 41 is pressed against the base 2'. Furthermore, the membrane 41 is also expediently heated by heating devices 40 ', for example infrared emitters, whereby the advantage is achieved that residues of the still liquid plastic solution or aqueous deposits on the membrane Solidify the plastic dispersion there and then easily remove it from the membrane.

The sealing strips 43, 44 are expediently made of a softer material than the membrane 41 and are glued or vulcanized onto the membrane 41.

If the plates 36 do not consist of metal, but of a heat-resistant plastic, it is possible to arrange the sealing strips not on the membrane but on these plates.

The membrane 41 can also be arranged on an endless steel belt.

In the embodiment according to FIG. 12, the carrier body consists of an endless band 46 made of steel or of an elastomeric, heat-resistant material which is supported by support rollers 47. Furthermore, heating devices 40 are also provided here.

The belt 46 carries a paper web 48, on the structured upper side of which a coating formed from an aqueous plastic dispersion or a liquid plastic solution is already applied, which forms the outer layer of the dressing. This paper web 48 replaces the base 2 '. The split leather 3 provided with the still aqueous plastic dispersion is placed on this paper web 48 in such a way that the wet side comes to rest on the paper web. A membrane 49 provided with all-round sealing strips 50 is slipped onto each split leather 3 placed on it. Each membrane 49 again has an opening 51 provided with a valve, via which the connection to a vacuum source takes place. By applying the vacuum, the membrane is pressed against the split leather again and the vapors are extracted. The split leather with the membrane is further conveyed through the belt 46. At the end of this band, the membrane is lifted off and the split leather removed from the paper web 48. The layer prefabricated on the paper web 48 then forms the outer layer of the dressing containing the pigment. The paper web can again be provided with such a layer and then used again.

The belt 46 is guided over rollers 52.

Again, grooves 41a are expediently provided on the side of the membrane 49 facing the split leather 3 in order to facilitate the removal of the vapors.

The movement of all vacuum devices described can be controlled so that it is adapted to the speed of the upstream devices, so that continuous production is possible.

In all devices, the membranes can consist of various products with elastomeric properties, such as natural rubber, synthetic rubber, silicone rubber and elastic polyurethane.

6 shows an enlarged split leather according to the invention on an enlarged scale.

The dressing consists of two layers 14a, 14b, hollow microspheres being embedded in the inner layer 14a which completely absorbs the fibers of split leather 13. This inner layer 14a is preferably color-neutral and contains no pigments or dyes.

The outer layer 14b, which is significantly thinner than the inner layer 14a, does not have hollow microspheres, but instead has such a proportion of pigments or dyes that the coloring of the finish is thereby determined. The top 16 of this outer layer 14b is again structured and therefore has a leather-like appearance.

example 1

• Eine zweischichtige Silikonunterlage, die mittels einer Asbestgewebeeinlage verstärkt ist, wird auf ein Fließband aufgelegt und während des Wietertransportes auf diesem Fließband mittels Infrarotstrahlen auf etwa 85°C erwärmt. Die Silikonunterlage hat eine Größe von 2,4 m² und eine Stärke von ca. 3 mm. Auf die etwa 85°C warme Silikonunterlage wird mittels Gießen eine ca. 45% Feststoff enthaltende wässerige Dispersion aufgetragen. Die Dispersion enthält ca. 40% Polyurethan und ca. 5% Weißpigment und hat eine Viskosität von ca. 60 Sekunden (die Bestimmung der Viskosität erfolgt im Ford-Becher bei einer 4 mm-Düse). Die naße Dispersion wird in einer Dicke von ca. 0,11 mm auf die warme Unterlage aufgetragen, wobei die Verdickung und die darauffolgende Verfestigung dieser Dispersion unmittelbar nach dem Auftreffen auf die Unterlage durch Wasserverdampfung erfolgt. Die Unterlage weist eine strukturierte Oberseite auf, so daß sich beim Verfestigen dieser das Pigment aufweisenden Schicht gleichzeitig die später sichtbare Narbenstruktur der Zurichtung bildet. Die verfestigte äußere Schicht hat eine Stärke von ca. 0,06 mm. Die Polyurethandispersion bildet einen Film mit einer Härte von ca. 90 Shore A.

A split leather prepared according to the invention, which is comparable in its appearance and properties to a full-grain natural leather of the same type and thickness, is produced as follows:

• A two-layer silicone base, which is reinforced with an asbestos fabric insert, is placed on a conveyor belt and heated to about 85 ° C on this conveyor belt during transport by infrared rays. The silicone pad has a size of 2.4 m ² and a thickness of approx. 3 mm. An aqueous dispersion containing approximately 45% solids is applied to the approximately 85 ° C silicone base by pouring. The dispersion contains approx. 40% polyurethane and approx. 5% white pigment and has a viscosity of approx. 60 seconds (the viscosity is determined in the Ford cup with a 4 mm nozzle). The wet dispersion is applied to the warm base in a thickness of approx. 0.11 mm, the thickening and subsequent solidification of this dispersion taking place immediately after striking the base by water evaporation. The base has a structured top side, so that when this layer containing the pigment solidifies, the scar structure of the dressing that is later visible forms at the same time. The solidified outer layer has a thickness of approx. 0.06 mm. The polyurethane dispersion forms a film with a hardness of approx. 90 Shore A.

During the consolidation, the base moves on the conveyor belt at a speed of 4.5 m / min. 8 meters after pouring on the dispersion containing the pigment, a split leather, to which an aqueous plastic dispersion had previously been applied, is placed with the wet side onto the pre-dried layer of the substrate containing the pigment without manual intervention. The split leather has a size of approx. 1.3 m ² and a thickness of 1.4 mm and has a bright chrome-green color.

The dispersion applied to the split leather is a polyurethane dispersion that contains approx. 62% solids. These solids essentially consist of 50% polyurethane and 10% hollow microspheres as well as a thickening agent. The aqueous dispersion has a viscosity of approx. 280 seconds (measured in a Ford cup with a 4 mm nozzle) and dries to a film with a hardness of approx. 65 Shore A and a density of approx. 0.78. The relative viscous dispersion was applied to the split leather by means of a roller which rotates in the opposite direction to the direction of movement of the leather, so that the dispersion is massaged into the leather using the shear forces and essentially fills all cavities between the protruding fibers. Due to the different lengths of the protruding fibers of the leather, the layer thickness cannot be determined. The application weight of the wet dispersion was approx. 240 g _{/ m2.}

After the leather is placed on the solidified pigment layer on the base, this leather is pressed onto the base by a soft, elastic roller covered with silicone, whereby any air pockets between the pigment layer and the wet plastic dispersion applied to the leather can escape. Thereafter, the leather provided with the dressing and placed on the base is brought together with the base into a warm vacuum device which is provided with a membrane, a vacuum being generated below the membrane, so that the membrane lowers and against the Leather presses. The membrane adapts to the contours of the leather and presses it onto the base. The gases and water vapors generated by the heating of the vacuum device are extracted via the vacuum line. After approx. 75 seconds, the finished leather can be removed from the vacuum device. During this time, the vacuum device has moved on, so that continuous production takes place.

Example 2

• Auf einem Papierträger mit einer negativen Narbenstruktur und eine Oberflächenausrüstung, die ein Ablösen eines Verfestigten Polyurethanfilmes ermöglicht, wird mittels einer Rakel bzw. Streichvorrichtung eine hochviskose Polyurethanlösung in einer Schichtdicke von ca. 0,13 mm aufgetragen. Die Polyurethanlösung enthält als Feststoffe im wesentlichen 38% Polyurethan und 3% Braunpigment. Die Lösung trocknet zu einem Film mit einer Dichte von ca. 1,05 auf, der dann eine Härte von ca. 98 Shore A besitzt. Diese Pigmentschicht wird auf dem Papierträger vorfabriziert, der Papierträger kann also zusammen mit der Pigmentschicht bis zu seiner Verwendung auf Lager gehalten werden.

A split leather with a grained, particularly abrasion-resistant finish is produced as follows:

• A highly viscous polyurethane solution in a layer thickness of approx. 0.13 mm is applied to a paper carrier with a negative grain structure and a surface finish which enables a solidified polyurethane film to be removed. The polyurethane solution essentially contains 38% polyurethane and 3% brown pigment as solids. The solution dries to a film with a density of approx. 1.05, which then has a hardness of approx. 98 Shore A. This pigment layer is prefabricated on the paper base, so the paper base can be kept in stock together with the pigment layer until it is used.

In the production of the preparation of a split leather, the paper carrier is placed on a base, for example a conveyor belt, and moves in the direction of the transfer point of the leather provided with the wet plastic dispersion, where the leather is placed with its wet side onto the pigment layer of the paper carrier without manual assistance becomes. The aqueous plastic dispersion applied to the leather is pigment-free and has a milky appearance.

The paper web with the leather placed on it then runs under the application device for applying the aqueous plastic dispersion onto the leather to a pair of rollers, where it is pressed on.

The composition and amount of the aqueous dispersion layer applied to the leather corresponds to that in Example 1.

Then the paper base with the split leather on it is taken over by a heated endless steel belt, which has a length of more than 12 meters and a width of more than 1.2 meters, and is transported through it in such a way that in those places where the leather lies on the paper web, a rubber cover acting as a membrane with a sealing frame and a valve-provided opening for connection to a vacuum source is placed on the leather so that it covers the leather. Then the air is sucked out below the rubber cover, so that the membrane presses against the leather due to the resulting negative pressure and presses the leather onto the paper or onto the steel band. Due to the pressure of the membrane on the leather, there is a good connection between the pigment layer on the paper web and the hollow microspheres, which embed the fibers of the leather, and solidify the dispersion layer. Due to the negative pressure and the effect of heat, this dispersion layer dries quickly.

The steel strip is heated to a temperature between 70 and 140 ° C by illuminating the underside of the steel strip using infrared radiators.

Approx. The valve is opened 60 seconds after the vacuum is applied and the rubber cover takes on its original shape due to its elastic properties. After removing the rubber cover, the finished leather can be peeled off the paper. The longitudinal and transverse grooves provided in the rubber cover ensure that the gases and water vapor can escape from the leather even when the membrane is pressed onto the leather by the vacuum.

The term "membrane" is by no means understood to mean only an elastomeric material clamped in a frame or other holder. The membrane can also consist of only a single or multi-layer elastomeric material and can have any shape, e.g. be designed like a lid. In any case, the membrane must have such a shape that it limits an evacuable cavity when placed on the support and / or on the base and is pressed against the leather when the vacuum is applied.

The continuous movement of the front Dressed split leather in the vacuum device, which is supported on the base, can be made not only in a substantially horizontal plane, but also, for example, in a paternoster-like manner in a substantially vertical direction or also in a direction that is oblique to the horizontal. However, a circular movement is expediently always carried out in such a way that the transport device always returns to a specific transfer point.

Claims (69)

1. Process for dressing skiver or leather fibre materials, wherein a liquid polyurethane-containing plastics material, optionally a polymer solution, is placed onto a textured surface of a base (2, 2'), preferably of silicone rubber, and is allowed to solidify by heating the base (2, 2') to produce an outer layer (14b) of the dressing with a textured surface produced in situ, and an aqueous plastics dispersion forming an inner layer (14a) of the dressing is subsequently placed onto the moving skiver (13) or the like and, together with the skiver (13) or the like in its wet phase, is laid onto the pre-solidified outer layer (14b), and wherein the dressing formed from the two layers (14a, 14b) is then subjected with the skiver (13) or the like to a pressure treatment, characterised in that across-linkable dispersion or solution is applied to the base (2,2'), a cross-linkable, preferably polyurethane-containing dispersion is subsequently applied to the moving skiver (13) or the like by means of a rotating application cylinder (6) in a quantity of between 150 g/m² and 450 g/m² in the wet phase, preferably in a quantity of about 300 g/m² in the wet phase, to form the inner layer (14a), a relative velocity existing between the application cylinder (6) and the skiver (13) or the like so that the aqueous, preferably polyurethane-containing dispersion is rubbed into the skiver (13) or the like, the drying and the beginning of cross-linking of the inner layer (14a) take place during the residence time on the base (2, 2') heated from the underside, wherein the steam produced during drying is carried off at least in part through the skiver (13) or the like during this time, and in that the finished skiver (13) or the like is subsequently removed from the heated base (2, 2').

2. Process according to claim 1, characterised in that the cross-linkable dispersion forming the inner layer (14a) has a higher viscosity than the cross-linkable dispersion or solution forming the outer layer (14b).

3. Process according to claim 1 or 2, characterised in that the dressing formed from the two layers (13a, 13b) together with the skiver (13) or the like is additionally subjected to a vacuum treatment as it solidifies.

4. Process according to claim 1, 2 or 3, characterised in that the skiver (13) or the like is laid onto an overlayer advantageously composed of paper before the placement of the cross-linkable dispersion or solution forming the inner layer (14a) of the dressing and is turned together with the overlayer and laid onto the pre-solidified outer layer (14b).

5. Process according to one of claims 1 to 4, characterised in that the pressure treatment and/ or vacuum treatment takes place together with an overlayer preferably composed of air-permeable paper.

6. Process according to one of claims 1 to 5, characterised in that the base (2, 2') is moved on as the polyurethane-containing dispersion or solution forming the outer layer (14b) is being applied.

7. Process according to one of claims 1 to 6, characterised in that the dressing formed from the two layers (14a, 14b) with the skiver (13) or the like is moved on during the pressure treatment and/or during the vacuum treatment together with the base (2,2').

8. Process according to one of claims 1 to 7, characterised in that the base (2, 2') is supported on a carrier (36) which is composed of metal and is heated at least in part during the pressure treatment and/or vacuum treatment.

9. Process according to one of claims 1 to 8, characterised in that the rotation of the application cylinder (6) is opposed to the direction of movement of the skiver (13) or the like.

10. Process according to one of claims 1 to 9, characterised in that, prior to application of the aqueous, preferably polyurethane-containing plastics dispersion to the skiver (13) or the like, microhollow spheres having a diameter of 0.008 to 0.1 mm having a thin shell composed of thermoplastic material, preferably of viny- lidenechloride copolymer, are added to this dispersion.

11. Process according to one of claims 1 to 10, characterised in that an aqueous, preferably polyurethane-containing plastics dispersion or liquid plastics solution which contains more than 40% by volume of solids is used.

12. Process according to one of claims 1 to 11, characterised in that an aqueous, preferably polyurethane-containing plastics dispersion or liquid plastics solution which contains pigments and/or dyes is used.

13. Process according to one of claims 1 to 12, characterised in that the aqueous polyurethane-containing plastics dispersion or liquid plastics solution forming the outer layer (14b) is poured or sprayed onto the base preferably composed of a silicone slab.

14. Process according to one of claims 1 to 13, characterised in that the aqueous plastics dispersion or liquid plastics solution forming the outer layer (14b) is poured or sprayed onto the already heated base (2, 2') while the heated base moves on and in that further heat is supplied to the base (2,2') as this aqueous plastics dispersion or liquid plastics solution is solidifying, and this base is moved on to the position where the skiver (13) or the like is laid on.

15. Process according to one of claims 1 to 12, characterised in that the polyurethane-containing plastics dispersion or liquid plastics solution forming the outer layer (14b) is placed onto the base preferably composed of a paper by means of a doctor.

16. Process according to one of claims 1 to 15, characterised in that a prefabricated strip of paper provided with a solidified plastics dispersion or plastics solution is used as a base.

17. Device for producing a dressing on a skiver (3) or the like with a support (1, 1') for the skiver (3) or the like to be dressed, a system (6) for applying an aqueous plastics dispersion to the skiver (3) or the like to form an inner layer (14a) of the dressing and a base (2, 2') with a textured surface, for example, with a negative leather grain texture for supporting a textured outer layer (14b) of the dressing, characterised in that at least a part of the support (1, 1') is movably guided round a return point (5), in the region of which the skiver (3) or the like provided with the dressing (4) is transferred to the base (2, 2') supporting the outer layer (14b) such that the skiver (3) or the like rests with the side having the aqueous plastics dispersion on the outer layer (14b) supported by the base (2,2'), and in that an application cylinder (6) for applying the aqueous plastics dispersion onto the skiver or the like is provided above the support (1).

18. Device according to claim 17, characterised in that the support (1) consists of an endless driven belt guided over at least two rollers (5), one of the rollers forming the return roller.

19. Device according to claim 17 or 18, characterised in that the belt forming the support (1) is provided with a covering, advantageously of paper, which preferably consists of a continuous strip.

20. Device according to claim 17, 18 or 19, characterised in that the direction of rotation of the application cylinder (6) is opposed to the direction of movement of the support (1).

21. Device according to one of claims 17 to 20, characterised in that the base (2) is formed by a moving conveyor belt.

22. Device according to claim 21, characterised in that the base (2) is formed by an endless conveyor belt guided by guide members.

23. Device according to one of claims 17 to 20, characterised in that the base (2') is formed by a plate-shaped carrier adapted to be moved by a conveyor system, for example conveying rollers (9).

24. Device according to one of claims 17 to 23, characterised in that the base (2, 2') is heated.

25. Device according to one of claims 17 to 24, characterised in that the base (2, 2') is composed of silicone rubber preferably provided with a reinforcement.

26. Device according to claim 25, characterised in that the reinforcement is composed of a nonwoven or woven fabric from glass, asbestos or carbon fibres.

27. Device according to claim 25 or 26, characterised in that the reinforcement is embedded in the base.

28. Device according to claim 25 or 26, characterised in that the reinforcement is disposed on the underside of the base.

29. Device according to one of claims 25 to 28, characterised in that the base (2') consists of two layers of differing rigidity and/or differing flexibility, the lower layer being more rigid and/or less flexible than the upper layer.

30. Device according to one of claims 17 to 24, characterised in that the base is formed by a paper having a textured surface preferably provided with a plastics coating, in particular by a strip of paper (47) adapted to be drawn off a roll.

31. Device according to one of claims 17 to 30, characterised in that a pouring, doctoring or spraying device (20) for applying a plastics dispersion or plastics solution to the base is provided above the base (2, 2').

32. Device according to one of claims 17 to 31, characterised in that a contact or pressing system (11, 11') acting upon the base (2, 2') supporting the skiver (3) or the like provided with a dressing (4) is provided.

33. Device according to one of claims 17 to 32, characterised in that a pre-dried layer, preferably a finish layer (12) which attaches itself to the dressing (4) is arranged on the base (2, 2').

34. Device according to one of claims 17 to 33, characterised in that at least one transfer cylinder (10) is provided in the region of transfer from the support (1) to the base (2, 2').

35. Device according to one of claims 17 to 34, characterised in that a drying system preferably formed by a vacuum device (24) is provided for the skiver (3) or the like located on the base (2, 2') and provided with the dressing.

36. Device according to claim 35, characterised in that the vacuum device (24) consists of at least two moving parts (29, 30; 36, 41; 46, 49) between which the skiver (3) or the like provided with the dressing is arranged, at least one of these parts (30, 41, 49) having elastomeric properties and" being provided with at least one closable orifice (32, 45, 50) which can be connected to a vacuum source so that a vacuum can be maintained between the two parts to press the part (30, 41, 49) having elastomeric properties against the skiver (3) or the like provided with the dressing.

37. Device according to claim 35 or 36, characterised in that the lower of the two parts is formed at least in part by the base (2') supported on a conveyor system (29, 36, 46).

38. Device according to claim 37, characterised in that the conveyor system consists of individual moving tables (29) on which the base (2') rests.

39. Device according to claim 38, characterised in that the tables (29) are movably arranged in a closed track.

40. Device according to claims 38 and 39, characterised in that the tables (29) are movably arranged about a centre (28') in a substantially circular track.

41. Device according to one of claims 37 to 40, characterised in that the conveyor system is formed from an endless revolving carrier (35, 46).

42. Device according to claim 41, characterised in that the carrier consists of individual plate-shaped or tubular elements (36) which are joined together.

43. Device according to claim 42, characterised in that the plate-shaped or tubular elements (36) are joined together by at least one conveying chain (38) guided round chain wheels (39).

44. Device according to claim 42, characterised in that the plate-shaped or tubular elements (36) are composed of metal, preferably of steel.

45. Device according to claim 42, characterised in that the plate-shaped or tubular elements (36) are composed of heat-resistant plastics material, for example of polyimide or of silicone rubber, and are preferably provided with a reinforcement of metal, for example of a wire mat, a woven fabric or a nonwoven fabric.

46. Device according to claim 41, characterised in that the carrier consists of an endless belt (46).

47. Device according to claim 46, characterised in that the carrier consists of a steel belt.

48. Device according to claim 46, characterised in that the carrier consists of a belt of elastomeric matterial, for example of silicone rubber.

49. Device according to one of claims 41 to 48, characterised in that supporting rolls (47) are provided beneath the carrier (46).

50. Device according to one of claims 37 to 49, characterised in that heating means, for example infrared radiators (40), are provided beneath the conveyor system or the carrier.

51. Device according to claim 36, characterised in that, of the two moving parts, the upper part has a membrane (30, 41, 49) of elastomeric material which is pressed against the skiver (3) or the like supported on the lower part and provided with the dressing, as a vacuum is building up between the two parts.

52. Device according to claim 51, characterised in that the membrane has an encircling sealing strip (31, 50) which rests on the conveyor system (29, 46) or on the base (2', 48) supported thereon, the membrane also being moved by the conveyor system.

53. Device according to claims 37 and 52, characterised in that several membranes (49) are arranged next to one another on the conveyor system (46), one respective membrane covering at least one dressed skiver (3) or the like, the membranes optionally being joined together.

54. Device according to claim 51 characterised in that the membrane is formed by a belt (41) which is composed of an elastomeric material and moves synchronously with the endless revolving carrier (36).

55. Device according to claim 54, characterised in that the belt (41) composed of elastomeric material and/or the carrier are provided at the edge regions extending in the direction of movement and optionally at predetermined intervals transversely to the direction of movement with sealing strips (43, 44) of elastomeric material.

56. Device according to one of claims 52 to 55, characterised in that the sealing strips (31; 43, 44; 50) are composed of a more flexible material than the membrane (30, 41, 49).

57. Device according to claim 52 or 54, characterised in that the sealing strips (31; 43, 44; 50) are stuck or vulcanised on the membrane (30, 41, 49) or on the carrier.

58. Device according to one of claims 36 to 57, characterised in that the orifices (32, 45, 51) for connection to the vacuum source are arranged in the sealing strips (31, 43, 50).

59. Device according to one of claims 36 to 58, characterised in that the orifices (32, 45, 51) are provided with valves for connection to the vacuum source.

60. Device according to one of claims 36 to 59, characterised in that the membrane (30, 41, 49) is provided with grooves (41a) on the side facing the skiver (3) or the like.

61. Device according to one of claims 36 to 60, characterised in that the membrane (30, 41, 49) is provided with a reinforcement, for example of metal, of a woven fabric or of a nonwoven fabric.

62. Device according to one of claims 36 to 61, characterised in that the membrane (30, 41, 49) is heated.

63. Device according to one of claims 17 to 62, characterised in that the region of transfer from the support (1) to the base (2, 2') is provided between the pouring, doctoring or spraying system (20) for applying the plastics dispersion or plastics solution to the base (2, 2', 48) and vacuum device (24).

64. Device according to one of claims 17 to 63, characterised in that the base (2, 2') is arranged beneath the application cylinder (6).

65. Device according to one of claims 17 to 63, characterised in that the base (2, 2') is arranged to the side of the application cylinder (6).

66. Device according to one of claims 17 to 65, characterised in that the support is formed by an arc-shaped return system which consists, for example, of conveying rollers (1') and is arranged between a conveyor belt (19) or the like conveying the skiver (3) or the like to be dressed and co-operating with the application cylinder (6) and the base (2, 2') and alters the direction of movement of the skiver (3) or the like.

67. Device according to one of claims 17 to 66, characterised in that the support (1) is composed of rubber or plastics material.

68. Device according to one of claims 17 to 67, characterised in that a compressed air nozzle (19) directed toward the skiver (3) or the like located on the support (1) is provided in the transfer region.

69. Device according to one of claims 17 to 68, characterised in that the velocity of the support (1) and of the base (2, 2') is adjustable, preferably smoothly adjustable.

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