CH709938A2 - Layered composite sheet-like porous layers. - Google Patents

Abstract

Layer composite (1) with a composite (2) of a plurality of flat porous layers (3, 4, 5), wherein each porous layer (3-5) at least one at least partially metallic surface (6), characterized in that the flat porous layers (3-5) via at least one common galvanic surface coating (7) are interconnected.

Description

The present invention relates to a composite layer of sheet-like porous layers. In this case, such a composite bearing, for example, consist of several wire fabric layers.

In the prior art, a layer composite of several wire fabrics has become known, wherein the respective planar and porous wire fabric layers are firmly connected to each other by a calendering or by at least one pressing operation and a subsequent thermal treatment. When exposed to considerable pressure from the outside, the individual wires of the wire fabric layers deform and interlock with each other, resulting in a solid layer composite after the thermal aftertreatment. Due to the high pressure occurring during calendering or during pressing, the thickness of the individual layers and thus also the total thickness is considerably reduced.

Inventive layer composites of porous layers are suitable for example for the filtration of various liquids or gases. But it is also possible to use in the acoustics for sound insulation, which can be broken by the individual flat porous layers of sound and thus better absorbed.

A disadvantage of the previously known layer composites of e.g. Wire mesh is the limited choice of different porous layers because not all different weaves, mesh sizes and wire diameters can be firmly and reliably connected together. In fact, in the combination of individual woven fabric layers in the selection of weaves, the mesh sizes and the wire diameter, the fabric layers to be joined together are limited to certain combinations.

It is therefore the object of the present invention to provide a layer composite of sheet-like porous layers available, in which different porous layers can be interconnected.

This object is achieved by a layer composite of sheet-like porous layers with the features of claim 1. Preferred developments of the invention are the subject of the dependent claims. Further advantages and features of the present invention will become apparent from the general description and the description of the embodiments.

An inventive layer composite comprises a composite of a plurality of flat porous layers. In this case, each porous layer has at least one at least partially metallic surface. Preferably, the individual porous layers have a substantially complete or even completely metallic surface. The flat porous layers are connected to one another via at least one common galvanic surface coating.

The inventive composite layer has many advantages. A considerable advantage of the novel layer composite is that a great variety of porous layers can be connected to one another. It is not necessary in the present invention that, for example, individual wires of individual porous layers interlock by pressure and combine with each other by diffusion under thermal action, but at least one common galvanic surface coating is applied, which firmly connects the porous individual layers. As a result, if, for example, wire meshes are used as porous layers, a wide variety of wire diameters can also be used in the individual woven wire layers. In this case, both very thin and very thick wires can be used without the risk that individual porous layers are damaged by the assembly.

The invention enables a finer and / or more defined filtration, since different filter layers can be interconnected. This also offers advantages in the application in acoustics, since the scattering of occurring sound waves is even greater, so that a more effective damping is achieved.

The layer composite can also provide a reservoir for, for example, solder or a solder.

In all cases, the individual layers are permanently connected to each other in the composite layer. The porous layers of the layer composite are in particular permanently connected to each other. This means that the composite of the porous layers is retained during normal handling and operation. Also acting vibrations or vibrations or bends by 90 ° or more do not destroy the composite of the majority of the sheet-like porous layers.

In a preferred embodiment, between 2 and 10 porous layers are joined together by the at least one common galvanic surface coating. In this case, identical or different porous layers can be connected to one another in order to set the desired filter or acoustic properties or the like as desired.

In all embodiments, it is preferred that the galvanic surface coating on at least one porous layer has two, three or more coating layers. At least one part and in particular each coating layer preferably consists at least essentially of catalytic materials. In all embodiments, the individual coating layers each consist at least to a substantial extent of nickel, chromium, gold, silver, copper, titanium, platinum, palladium and / or tin. In particular, a coating with several different coating layers is possible and preferred.

The thickness of a coating system of the surface coating is preferably between 1 .mu.m and 100 .mu.m and in particular between 1 .mu.m and 50 .mu.m. A total thickness of the surface coating is preferably between 1 .mu.m and 200 .mu.m, but in individual cases may also be up to 300 .mu.m or more. It is also possible that individual or many pores of at least one porous layer are closed by the galvanic surface coating.

In all embodiments, the individual porous layers each have pores. In a preferred development, the galvanic surface coating sets a pore size of at least some pores of a porous layer.

In particular, a pore size of at least some and in particular all pores of a porous layer is adjusted by the thickness of the surface coating. This allows a particularly accurate and defined adjustment of the pore size of the pores of a porous layer. A targeted galvanic coating can specifically influence the size of the pores.

It is also possible that first a porous layer or a plurality of porous layers are each individually electroplated to affect the respective pore size of the respective pores of the respective porous layers defined.

In all embodiments, it is preferred that at least one porous layer is a wire fabric layer. Wire cloth layers, for example, have the advantage that they allow a high open area and at the same time can be made very reproducible and exact.

A layer composite of several wire fabric layers over a galvanic surface coating is very advantageous. In the prior art, the wire cloth layers had to be pressed together and then thermally treated. This changes the geometric conditions as well as the material properties.

With the novel layer composite specifically defined geometric properties are set. The grain structure of the porous layers is not changed.

In all embodiments, it is preferred that at least some wires of the wire fabric layer consist of a metal. It is also possible that at least some wires of the wire fabric layer consist of a non-metal and / or have an electrically conductive surface coating. For example, it is also possible to use plastic wires which receive a metallic surface coating, so that these wires, which essentially consist of plastic, can also be connected to the other porous layers by means of a galvanic surface coating. Such an electrically conductive surface coating is in particular a metallic surface coating. A variety of metals are suitable for this purpose. The shape and the contour of the wires of a wire mesh are basically arbitrary. For example, round or square cross sections are possible. The outer contour may be regular or irregular.

It is particularly preferred that at least two porous layers consist of wire fabric layers. In particular, all porous layers are designed as wire fabric layers. But it is also possible that at least one layer consists of a perforated plate, an expanded metal, a non-woven, a welded mesh or a similar porous material.

In all embodiments, it is preferred that the orientation of different porous layers may be different from each other. For example, the orientation of the wires in the wire meshes of at least two wire meshes may be shifted from one another and / or twisted. The individual wires can run at any angle or parallel to each other.

One or at least one wire fabric layer of a layer composite according to the invention can have a wide variety of weaves. The fabric may have open meshes and thus have open through openings perpendicular to the surface. But it is also possible that the stitches are tightly beaten. The wire fabric layer can be designed as a weave fabric, resulting in only skew open pores, while the wire fabric layer is opaque perpendicular to the fabric surface. This means that the mesh size can be reduced to zero. Due to the three-dimensionality of a wire mesh, open pores with a small opening width also result in a turgid tissue, but the open pores are then oriented obliquely to the tissue surface.

In many cases, a large open area or a high proportion of the open area on the filter surface is desired for filter applications. A wire thickness of the warp wires and the weft wires can be basically arbitrary. Possible are the same and different strength warp wires and weft wires.

In all developments, it is possible that the wires each consist of monofilaments or multifilaments. It is also possible that both the warp wires and the weft wires of a wire fabric layer or all wire fabric layers each consist of multifilaments. Then all the multifilaments are coated by the common galvanic surface coating and thus the multifilaments and the individual porous layers are joined together. It is also possible that the individual multifilaments are galvanically coated or otherwise coated before the wire mesh is made from them. Subsequently, the individual wire fabric layers can be connected to one another via a galvanic coating.

It is possible and preferred that the porous layers are only partially connected to each other via the common metallic surface coating. It is possible that the common galvanic surface coating extends over a plurality of segments, on the other hand, further segments partially or flatly have no common metallic surface coating.

The pore size of different porous layers is preferably different. This allows a particularly fine filtration.

In all embodiments, at least one support layer can be provided. Such a support layer can serve to support the layer network and, in principle, need not be provided for further filtration purposes. In all embodiments, it is possible that at least one porous layer and / or the composite is compacted and / or calendered. Such densification and / or calendering may be done before or after galvanic surface coating.

An inventive layer composite can be prepared as a blackboard, roll or coil.

The invention provides a novel semi-finished product which has improved properties. Due to the common galvanic surface coating, a variety of different porous layers can be firmly and reliably connected. In this case, the basis weight can be reduced. The pore size of the individual porous layers is essentially freely selectable. Selected material combinations can be used to set specific absorption properties for use in acoustics, for example, which were previously not possible.

In this case, the material properties of the porous layer composite per se are not changed by the common galvanic surface coating, but it is a common layer composite created, for example. has precisely defined filter properties. A thermal aftertreatment with high temperatures of over 1000 ° C is not necessary.

Such a layer composite may be designed as a laminate and have at least one coating of, for example, nickel, chromium, gold or the like. Preferably, at least one wire fabric layer is provided. The individual layers can be arranged at an angle to each other or arranged in parallel, overlapping or partially overlapping.

Basically, it is possible in the use of, for example, wire mesh or a nonwoven fabric as a porous layer to produce the wire mesh or the fleece of different materials. It is possible to use metals, plastics, organic or inorganic or hybrid materials. In this case, at least part of the material used is provided with a metallic surface layer before the galvanic coating, if the surface was not already electrically conductive in itself.

After the production of the layer composite this can be calendered. It is also possible during further processing to weld the layer composite to other parts. In this case, a resistance welding or ultrasonic welding or the like can take place.

In principle, the layer composite can also serve as a carrier material of substances. It is possible, e.g. the use as an electrode, wherein a stock material is provided as a solder material, which later serves for soldering and for electrical contacting of the porous layer or the layer composite with other components.

It is possible, for example, the use in a fuel cell for filtering the fuel. The use is also possible in the chlorine gas production or in the heat and the heat. The invention can also be applied to the acoustic field for sound insulation. Also possible and preferred is the targeted passage of air, for example, for the fluidization of bulk solids. The invention can also be used during transport or in the exhaust gas recovery or in conjunction with ceramic and metal, for example for screening. In the field of architecture, the use as a visible component offers. It is also possible to use shielding to prevent electromagnetic radiation from certain components or areas.

Further advantages and features of the present invention will become apparent from the embodiments, which are explained below with reference to the accompanying figures. In the figures show: <Tb> FIG. FIG. 1 shows a highly schematic cross-sectional view of a layer composite of flat porous layers according to the invention; FIG. <Tb> FIG. 2 <SEP> another highly schematic cross-sectional view of a layer composite according to the invention; <Tb> FIG. 3 <SEP> a single porous layer with a coating layer; <Tb> FIG. 4 <SEP> another areal porous layer with two coating layers; <Tb> FIG. 5 <SEP> another layer composite in a highly schematic cross-sectional view; <Tb> FIG. FIG. 6 shows a highly schematic top view of the layer composite according to FIG. 5; FIG. <Tb> FIG. 7 <SEP> an enlarged detail of a fabric layer of the layer composite according to FIG. 6; <Tb> FIG. 8 <SEP> is a further enlarged detail of another flat porous layer of the layer composite according to FIG. 6; and <Tb> FIG. 9 <SEP> a multifilament of a wire fabric layer of the layer composite according to FIG. 6.

Fig. 1 shows a first highly schematic illustrated embodiment of an inventive layer composite 1 in a cross section. The layer composite 1 consists of a composite 2 of here several flat porous layers, which comprise the sheet-like porous layers 3, 4 and 5. All porous layers here each have completely metallic surfaces 6.

The sheet-like porous layers 3, 4 and 5 are fixedly connected to one another via a common galvanic surface coating 7. Firmly connected here means that the individual layers of the layer network do not separate again during normal use. It is even possible to bend the layer composite by 90 ° or more without local or planar detachment of the individual porous layers from each other.

As FIG. 2 shows, it is also possible that the composite 2 not only has a single coating layer 8, but the galvanic surface coating 7 can also consist of two or even more coating layers 8, 9. The total thickness of the surface coating 7 of the composite 2 is then composed of the thickness 10 of the coating layer 8 and the thickness 11 of the coating layer 9. Since the individual porous layers 3, 4 and 5 each have non-visible pores 17 in FIGS. 1 and 2, the common galvanic surface coating 7 is not only arranged around the individual sheet-like porous layers 3, 4 and 5, but is also located on the surfaces in the individual pores 17.

Fig. 3 shows, for example, the porous layer 4 of a composite layer 1 of FIG. 1 or 2. The porous layer 4 is formed here as a wire fabric layer 14 and has warp wires and weft wires (shown hatched here). After weaving the wire fabric layer 14, it is galvanically coated with a coating layer 8. This results in the structure shown in Fig. 3.

But it is also possible that, for example, the porous layer 5 shown in Fig. 4, which is also designed here as a wire cloth layer 15, after weaving with, for example, two different coating layers 8 and 9 is successively electroplated. The individual coating layers 8 and 9 may consist of the same or of different materials. For example, first a copper layer can be applied, which is then surrounded by a nickel layer or other materials.

After the preparation of individual porous layers 3, 4 and 5, these are connected to one another with a common galvanic surface coating. The finished state is shown in FIG. 5 in a highly schematic cross-sectional view. Here, an uncoated wire fabric layer 13 was connected as a flat porous layer 3 with the single-coated wire fabric layer 14 of FIG. 3 and a double-coated wire fabric layer 15 of FIG. 4 by a surface coating 7. This means that the surface coating 7 here is the outermost galvanic surface coating that connects all the layers together.

In other embodiments, it is also possible to first connect two wire fabric layers or other sheet-like porous layers to each other via a first common galvanic surface coating and then to this first composite with another or with several other planar porous layers via a further common galvanic surface coating connect. In all these cases, in the context of the present invention, a layer composite with a plurality of areal porous layers is created, which are surrounded overall by a common galvanic surface coating.

Fig. 6 shows a highly schematic plan view of a layer composite 1, for example, two different porous layers 3 and 4, which also here again preferably made of wire fabric layers 13, 14.

The layer composite 1 has an edge region 27 and a central region 28. The edge region 27 can be compressed, for example by a pressing operation. Here in the exemplary embodiment, the two porous layers 3 and 4 are arranged at an angle 25 from here 45 ° to each other. This means that the warp wires of the two porous layers 3, 4 each extend at an angle of 45 ° to each other. The same applies to the weft wires of the wire fabric layers 13, 14.

But it is also possible that the individual porous layers are arranged parallel or at other angles to each other to adjust the desired properties.

FIG. 7 shows a detail enlargement of the flat porous layer 3 for the layer composite from FIG. 6 before the coating. The wire mesh 13 has pores 17. The wire mesh 3 has a fabric type 24 and a mesh size 21 and defined wire diameter.

FIG. 8 shows an enlarged detail of the flat porous layer 4 of the layer composite 1 from FIG. 6. Here, the details of FIG. 7 and FIG. 8 are reproduced on the same scale. This means that the mesh size 21 of the flat porous layer 4 is considerably larger than the mesh size 21 of the flat porous layer 3. Also, the wire diameter of the wire mesh of the sheet-like porous layer 4 are considerably larger than the wire diameter of the wire mesh of the sheet-like porous layer 3. Similarly, the pores 17 of the sheet-like porous layer 4 have a larger pore size 16 than the pore size of the sheet-like porous layer 3. In the galvanic surface coating, the two flat porous layers 3 and 4 are positioned directly on one another, a galvanic surface coating is performed around all the wires of the wire fabric layers 13 and 14 so that a solid composite 2 is produced.

In all cases, it is possible that a multifilament 26 is used as the wire. Such multifilaments 26 are also completely surrounded by a common galvanic surface coating.

Overall, the invention provides an advantageous layer composite 1 available, which is particularly suitable but not only for use in the filtration. In this case, a wide variety of porous layers can be firmly connected to each other. For example, a wire mesh layer of 0.25 mm mesh size and 0.14 mm wire diameter can be connected to a second woven mesh layer having a mesh size of 0.5 mm with a wire diameter of 0.16 mm. Optionally, a third wire fabric layer can be connected to the first two, which in turn has a mesh size of 0.25 mm with a wire diameter of 0.14 mm. Such a layer composite is suitable for example for the filtration of foreign substances from fuels or other liquids. Depending on the application example, larger and smaller mesh sizes and wire diameters can be used.

In principle, a wide variety of metals could be applied by electroplating. In the last-mentioned layer composite, for example, a coating with nickel can be useful, which has a coating thickness between about 1 and 30 microns.

For galvanic coating, different steps may be useful or necessary, for example, a first bath may be designed as acid bath, while or after an activation bath may be provided before finally the actual galvanic coating bath is provided.

In contrast to the prior art, in which a plurality of wire fabric layers are connected to each other via calendering, different porous layers can be joined together here. In the prior art, a thermal aftertreatment of the calendered layers was required regularly, which was carried out at 1000 ° C or more. Such a high temperature regularly causes a change in the grain structure, wherein the connection takes place on the one hand by a mechanical entanglement of the calendering and on the other hand by a thermal diffusion due to pressure, temperature and time. This results in changes to the pore size and the structure of the individual layers, which may be disadvantageous in some cases. In contrast, such disadvantages are avoided by the galvanic surface coating of the layer composite according to the present invention.

Such a layer composite is also suitable for use as a double-layer electrode, as a reservoir during soldering and the like.

LIST OF REFERENCE NUMBERS

[0057] <Tb> 1 <September> Location composite <Tb> 2 <September> Composite <tb> 3 <SEP> porous layer <tb> 4 <SEP> porous layer <tb> 5 <SEP> porous layer <Tb> 6 <September> surface <Tb> 7 <September> surface coating <Tb> 8 <September> coating layer <Tb> 9 <September> coating Läge <tb> 10 <SEP> Thickness of 8 <tb> 11 <SEP> Thickness of 9 <tb> 12 <SEP> Thickness of 7 <Tb> 13 <September> Wire fabric layer <Tb> 14 <September> wire mesh Läge <Tb> 15 <September> Wire fabric layer <Tb> 16 <September> pore size <Tb> 17 <September> Pore <Tb> 18 <September> Wire <Tb> 19 <September> Wire <tb> 20 <SEP> Surface coating (electrically conductive) <Tb> 21 <September> mesh <Tb> 22 <September> wire diameter <Tb> 23 <September> division <Tb> 24 <September> tissue <Tb> 25 <September> Angle <Tb> 26 <September> multifilament <Tb> 27 <September> edge area <tb> 28 <SEP> central area

Claims (19)

A composite layer (1) having a composite (2) of a plurality of flat porous layers (3, 4, 5), each porous layer (3-5) having at least one at least partially metallic surface (6), characterized in that the flat porous layers (3-5) are connected to one another via at least one common galvanic surface coating (7). 2. layer composite (1) according to claim 1, wherein between two and ten porous layers (3-5) are interconnected by the at least one common galvanic surface coating (7). 3. layer composite (1) according to any one of the preceding claims, wherein the galvanic surface coating (7) a plurality of coating layers (8, 9), each comprising at least a substantial portion of catalytic materials such. As nickel, chromium, gold, silver, copper, titanium, platinum, palladium or tin exist. 4. layer composite (1) according to the preceding claim, wherein a thickness (10, 11) of a coating layer (8, 9) of the surface coating (7) between 1 .mu.m and 100 .mu.m and in particular between 1 .mu.m and 50 .mu.m. 5. layer composite (1) according to any one of the preceding claims, wherein a thickness (12) of the surface coating (7) is between 1 micron and 200 microns. 6. layer composite (1) according to one of the preceding claims, wherein by a thickness (12) of the surface coating (7) a pore size (16) of at least some pores (17) of a porous layer (3-5) is adjusted. 7. layer composite (1) according to any one of the preceding claims, wherein at least one porous layer (3-5) is a wire fabric layer (13-15). 8. layer composite (1) according to the preceding claim, wherein at least some wires (18) of the wire fabric layer (13-15) consist of a metal. 9. layer composite (1) according to one of the two preceding claims, wherein at least some wires (19) of the wire fabric layer (13-15) consist of a non-metal and / or an electrically conductive surface coating (20). 10. layer composite (1) according to any one of the preceding claims, wherein at least two porous layers (3-5) consist of wire fabric layers (13-15). 11. layer composite (1) according to the preceding claim, wherein at least two wire fabric layers (13-15) have different fabric parameters or weaves. 12. layer composite (1) according to one of the two preceding claims, wherein the orientation of the wires in the wire fabrics of at least two wire mesh is shifted from each other and / or rotated. 13. layer composite (1) according to any one of the preceding claims, wherein at least some wires (18, 19) consist of monofilaments or multifilaments (26). 14 layer composite (1) according to any one of the preceding claims, wherein at least one porous layer (3-5) consists of a perforated plate, an expanded metal, a non-woven or a welding grid. 15. Layer composite (1) according to one of the preceding claims, wherein the porous layers (3-5) are only partially connected to each other via the common metallic surface coating. 16 layer composite (1) according to any one of the preceding claims, wherein the pore size (16) of different porous layers (3-5) is different. 17. Layer composite (1) according to one of the preceding claims, wherein at least one support layer is provided. 18. Layer composite (1) according to one of the preceding claims, wherein at least one porous layer (3-5) and / or the composite (2) is at least partially compressed and / or calendered. 19. Layer composite (1) according to one of the preceding claims, wherein the composite (2) is prepared as a blackboard, roll or coil.