WO2018091531A1

WO2018091531A1 - Method for producing a filter medium, filter medium, and filter element

Info

Publication number: WO2018091531A1
Application number: PCT/EP2017/079323
Authority: WO
Inventors: Anton Kreiner; Franz-Josef Holzner
Original assignee: Mann+Hummel Gmbh
Priority date: 2016-11-15
Filing date: 2017-11-15
Publication date: 2018-05-24
Also published as: DE102017010552A1

Abstract

The invention relates to a method for producing a filter medium (1) for a fluid filter, in particular in a motor vehicle, having the following steps: providing (S1) a flat filter material (2); providing (S2) a grating (3); arranging (S3) a meltable connection material (4) between the filter material (2) and the grating (3), said meltable connection material (4) being applied onto the grating and/or onto the filter material (2); thermally liquefying (S4) or allowing the connection material (4) to soften, the melting temperature of the connection material (4) being lower than the melting temperature of the grating material (3); placing the filter material (2) and the grating (3) against each other, wherein the placement is carried out prior to, during, or after the step of thermally liquefying or allowing the connection material to soften; and allowing (S5) the connection material (4) to solidify in order to form a bonded connection between the grating (3) and the filter material (2) by means of the connection material (4).

Description

description

Method for producing a filter medium, filter medium and filter element Technical field

The present invention relates to a method for producing a filter medium for a resource of a motor vehicle, such as. B. liquid resources such as oil. Furthermore, the invention relates to a filter medium and a filter element.

State of the art

Filters or filter elements usually comprise a filter medium which makes it possible, for example, to filter a fluid. A fluid may be an oil, a fuel, a urea solution or another fluid. The filter medium can be shaped into a star-shaped folded endless bellows. To form such a continuous bellows, a first end portion of the filter medium and a second end portion of the filter medium are connected together. In this case, the filter medium may have a plurality of folds. In order to ensure spacing between two adjacent folds, the filter medium may comprise a grid applied to a filter material. For example, DE 43 95 947 T1 describes that drainage layers can be in the form of a net or a grid or as a porous woven or nonwoven layer. EP 0 084 143 B1 discloses a method for producing a filter mat in which thermally softenable fibers are combined alone or in admixture with non-softenable fibers to form a nonwoven. The nonwoven is placed on a thermally softenable grid with discretely distributed convexed areas that rise at least 0.3 mm above the surface of the nonwoven. The grid has a melting point of 50 ° C or more below the melting point of the thermally softenable fibers. From the direction of the web is heated to a temperature which is at least 20 ° C above the melting point of the grid, but below the melting point of the thermally softenable fibers. For mutual connection, a compression is carried out, so that a filter mat of a nonwoven fabric and a point melted grid is formed. The melting of the grid itself or the introduction of additional, liquid adhesive for the connection of mesh and filter medium has the disadvantage that the filter pores can close by the melting and the filtration properties can thereby adversely affect, in particular, can block the filter pores. In addition, in the case of melting the grid the thickness of the grid changed adversely, so that the lattice properties, in particular the mechanical stability and the spacing and thus the drainage function of the grid are adversely affected.

DISCLOSURE OF THE INVENTION Against this background, the object of the present invention is to provide an improved method for producing a filter medium and an improved filter medium and filter element in that the application of a grid to a filter medium does not adversely affect the filtration properties of the filtration properties of the same filter medium In particular, a method for providing a filter medium with a grid applied thereto and such a filter medium is to be provided in which the filter pores of the filter material are not adversely changed by applying the grid, in particular closed, for example by additionally applied liquid Glue. It is therefore an object of the present invention to provide a filter medium with a grid and a filter material and a method for its production, wherein the grid can fulfill the drainage function for the oil flowing through as a spacer and as a mediator of mechanical stability without the pores of the filter material be closed by the application of the grid. It is a further object of the present invention to provide a filter medium and a method for the production thereof, wherein a high-quality weld seam is made possible between the filter material and the grid without having to completely melt through the grid and / or the filter material for the material bond , It is another object of the present invention to provide a filter medium and a method of making the same, wherein the thickness of the grid need not be reduced for connection to the filter medium.

Accordingly, a method for producing a filter medium for a fluid filter, in particular in a motor vehicle, is proposed. The method comprises the following steps: providing a flat filter material; Providing a grid; Placing a fusible bonding material between the filter material and the grid, wherein the fusible bonding material is applied to the grid and / or applied to the filter material; thermally liquefying or softening the bonding material, wherein a melting temperature of the bonding material is lower than a melting temperature of the mesh material; Aneinan- laying of the filter material and the grid, wherein the juxtaposition can occur before, during or after the thermal liquefaction or softening; Solidifying the bonding material to form a material bond between the grid and the filter material by means of the bonding material. By realizing the bonding of the filter material to the grid by means of thermal liquefaction or softening and solidification of the joining material, a fast bond between the filter material and the grid can be rapidly established since the bonding material can solidify in a relatively short time. Furthermore, the thermal liquefaction or softening of the bonding material can be inexpensively implemented in a flow production, since only locally a temperature increase must be realized. The solidification of the connecting material can be done accordingly after passing through the temperature increase.

For example, the filter material is a nonwoven material. In the present case, a "nonwoven material" is understood as meaning a material which comprises nonwoven fabric. A nonwoven fabric is a fabric of limited length fibers, filaments or cut yarns of any kind and of any origin which are joined together in any nonwoven fashion into a nonwoven (fibrous layer, fibrous web) and bonded together in any nonwoven fashion have been. Suitable types of composite of the fibers with each other in the nonwoven fabric are the form-fitting, z. As by entanglement, and / or the cohesion and / or adhesion, wherein the fibers can be oriented or confused in the nonwoven fabric.

The filter material may also include paper or other suitable material for filtration. Suitable materials include foam, thus a foamed plastic with cellular structure, textiles, and membranes, for example Polymermebranen.

In the present case, a "grid" is understood to mean a structure which comprises webs, wherein the webs are arranged such that intermediate spaces or continuous openings are formed between the webs. The use of a grille in a liquid filter has the advantage of preventing crimping of wrinkles. Such crimping is caused by the high pressure drops that typically occur in liquid filters in a non-meshed filter. The grid prevents a flat "jamming" or sticking together of fold sections, since a spacing of the fold sections is ensured by the webs.

The grid is made up of a large number of meshes. Preferably, an opening defines an area of the filter mat that is greater than 0.1, 0.2, 0.5 or 1 mm ² . The surfaces have, for example, a quadrangular geometry. The surfaces may in particular be diamond-shaped, parallelogram-shaped or square-shaped. Alternatively, the surfaces may also be oval or round.

In the present case, a "fusible bonding material" is understood as meaning a material which, when a specific temperature or a specific temperature range is exceeded, can be converted from a solid state of aggregation into a liquid state of matter. This transfer can also be referred to as melting. Furthermore, when the temperature falls below a certain temperature or a certain temperature range, the bonding material can be converted from the liquid state of matter into the solid state of aggregation, forming a cohesive connection. This may be referred to as solidification or solidification of the bonding material. Suitable softening or melting temperatures of the bonding material are in a range of, for. B. 70 to 500 ° C, preferably 80 to 400 ° C, particularly preferably 100 to 300 ° C. For the described changes in the states of aggregation, an approximately constant external pressure is assumed. Preferably, atmospheric pressure prevails [normal pressure (standard conditions)]. Suitable fusible bonding materials are, for example, thermoplastics. A thermoplastic is a plastic that is reversible (thermoplastic) deformable in a certain temperature range. Thermoplastics are also weldable. The thermoplastic can accordingly assume a soft, liquid or molten state. Suitable thermoplastics are polyolefins, polyamides, or polyesters. The fusible bonding material may, for example, when the temperature increases, assume a state in which it is deformable such that a material bond with another material can be entered. For example, the fusible bonding material is formed as a fusion adhesive bonding material. The fusible bonding material has a lower melting temperature than the mesh. Preferably, the fusible bonding material has a melting temperature which is 1 to 40 ° C, more preferably 10 to 20 ° C below the melting temperature of the grid. For example, a grid may be formed of a polyolefin, polyamide or polyester, and the fusible link may be made of any one of Melting temperature corresponding to lower selected co-polyolefin, co-polyamide or co-polyester may be selected, wherein the base polymer is preferably from the same group, so illustratively exemplified for the group of suitable thermoplastics, a polyolefin mesh with a co-polyolefin compound material used become. Suitable combinations include polyester / copolyester; Polyphenylene / polyethylene (PP / PE) or polypripopylene / co-polypropylene (PP / CoPP), polyamide / co-polyamide (PA / CoPA) or mixtures thereof.

The grating material in one embodiment has an equally high or higher melting temperature than the filter material. The lattice preferably has a melting temperature which is 1 to 40 ° C., more preferably 10 to 20 ° C. above the melting temperature of the filter material. This has the advantage that the filter material in its thickness or structure is not adversely affected by melting. The filter material also can not have a melting point.

The term "thermal liquefaction or softening" is understood here to mean the generation of a state by means of a temperature increase or a heat input in which the bonding material can plastically change its state and thereby adapts the surface of the bonding material to a bonding partner. The adaptation of the surface of the connection material to the connection partner can also be understood as wetting. By "solidifying" is meant in this case the solidification of the connecting material. Thus, the bonding material, in particular by allowing to cool below the melting temperature, in a solid state.

In the present case, a "cohesive connection" is understood as meaning a connection in which the connection partners are connected to one another by fusion, by intermolecular or chemical bonding forces or, if appropriate, by additives In this case, the connection between the connection material and the filter material as well as the connection between the connection material and the grid are regarded as materially cohesive.The connection between the filter material and the non-destructive detachable connections and lattice is also regarded as cohesive, wherein the bonding material is present as an intermediate layer and thus as a bonding agent Form fit and / or Reibkraftschluss between the filter material and the grid are present. A "positive connection" is created by the meshing or grasping of at least two connection partners.

A frictional connection presupposes a normal force on the surfaces to be connected to each other, whereas frictional connections ensure frictional engagement, and the mutual displacement of the surfaces is prevented as long as the counterforce caused by the static friction is not exceeded.

The filter material and the grid are held together by means of the fusible bonding material, wherein the fusible bonding material preferably exclusively has melt-adhesive bonding properties. In other words, the fusible bonding material serves as an adhesive, wherein the material closure takes place by heat input and juxtaposition or optionally also by additional pressure or compression. Illustratively, the connection is made by means of the connecting material by "ironing" the grid on the filter material, where the additional, optional minimum pressure is the pressure corresponding to the weight of the grid or the filter material, thus becoming the grid and / or the filter material made "ironable" by the fusible bonding material.

In one embodiment, the thermal liquefaction or softening and compression may be performed in parallel for additional process optimization.

The fusible bonding material preferably has no or substantially no solvent. The fusible bonding material also can not have a chemically curing component. Alternatively, the fusible bonding material may comprise a chemically curing ingredient and / or a solvent. Meltable bonding agents which have no or substantially no solvent have the advantage that they are easier and safer to manipulate and process in terms of storage technology and for occupational safety aspects compared to solvent-containing alternatives. The filter material and the grid can be connected only partially or partially cohesively. This has the advantage that a larger area of the filter material can be used for filtering. The mesh material includes, for example, polyester. The fusible bonding material includes, for example, co-polyester. The fusible bonding material can also serve as a sealing layer.

In further embodiments, the bonding material and the grid material comprise fusible plastic, wherein a melting temperature of the grid material is higher than a melting temperature of the bonding material.

This has the advantage that a heat input or a heating can be selected such that the connecting material softens or begins to liquefy and the grid material substantially retains its state of aggregation. The fusible plastic comprises, for example, a thermoplastic or consists entirely of it. For example, the bonding material may be referred to as a low melting component and the mesh as a higher melting component.

In embodiments, the grid and the bonding material are extruded into a two-layer grid, in particular coextruded. This embodiment is particularly preferred since it is particularly cost-effective, since it requires only one process step to produce the grid. The production is also cost-effective by the saving of additional liquid adhesive and has a relation to the use of a liquid adhesive increased occupational safety. The compound material layer has a complete adhesion and is therefore not destructive separable, this allows a particularly simple processing. The lattice is descriptively "ironed out." The lattice is clearly described in one layer out of the extrusion die as a multilayer composite in one process step, without the melts of lattice material, possibly of the filter material, and the fusible bonding material mixing during the extrusion The individual layers, filter material, bonding material and grid material are thus distinguishable from one another and are materially separated.The bonding material adheres to the respective surface and makes it "ironable", ie integrally bondable by heat input and juxtaposition or optional additional compression. This allows a high-quality weld without completely melting the grid or filter material. Preferably, the grid and the connecting material are materially connected to each other. For example, the grid and the connecting material are integrally formed. For example, the two-layer grid is formed by coextrusion. For example, a two-layer coextrusion die is used. examples For example, the two-layer co-extrusion die is supplied with a liquefied lattice matehal and a liquefied bonding material. In this case, the liquefied lattice material can also be referred to as a lattice raw material and the liquefied connecting material as a connecting raw material. The lattice raw material and the raw joining material may be formed into a lattice structure as stratified strands. In other words, in the extrusion process, in particular the coextrusion process, the lattice raw material and the compound raw material, preferably with different melting points, are extruded over one another. This results in a grid, which is composed of two layers. Preferably, the compound raw material has a lower melting point than the lattice raw material. Illustratively, this has the additional advantage that the fact that the raw material is melted at lower temperatures, the "Ironing" or cohesive prototypes or cohesive, thermal forms by juxtaposition or additionally under pressure, without destruction or damage to the Gitterrohmateri- than in particular, without reducing the thickness of the grid raw material, since the grid raw material has not yet melted at the melting temperature of the bonding raw material, this is particularly important since, in particular, a reduction in the thickness of the grid material reduces or even destroys the drainage function of the grid material Alternatively, the fusible bonding material may be extruded to the mesh or mesh to the bonding material.

In embodiments, the bonding material comprises melt fibers applied to the filter material. However, the filter material and the fusible bonding material may also be in the form of core-sheath fibers ("core-shell fibers") .The bonding material and the filter material may also be extruded, in particular coextruded, together As can be seen, the (co) extruded fiber of the filter material has a lower melting layer on the outside (sheath) and a higher melting point on the inside (core), the inner layer when joining, in particular cohesive thermal joining, is not melted. In embodiments, the bonding material is sprayed onto the grid and / or the filter material. The spraying takes place for example with the aid of a spray nozzle. This can be done for example when unwinding the filter material or the grid. For example, the fusible bonding material is in a liquid state during spraying. This has the advantage that, for example, after the spraying by solidification of the connecting material a cohesive connection can be formed. Accordingly, for example, the liquefaction of the connecting material takes place already during or before the spraying process. The spraying has the advantage that it can be done directly in the production of the filter medium inline (in a continuous manufacturing process). Thus, no additional, separate process step is required. The sprayed-on bonding material is additionally advantageous a thermoplastic, in particular a so-called hot melt adhesive, which is applied to the adhesive surface in the hot state, in particular sprayed, is immediately solidified after the spray application and thereby forms a firm connection with the grid and / or the filter material. This has the further advantage that the filter medium can be conventionally wound and can be "ironed out" during subsequent cohesive, thermal forming by heating and juxtaposition or additionally by compression, in particular, for example, by a heated roller is not destroyed by the connection with the grid, because the fusible bonding material is clearly applied as a first again solid but selectively remeltable melt adhesive on the surface of the fiber of the filter material and the melting temperature is below the melting temperature of the filter material, or no thermal degradation takes place Embodiments convey the filter material, the connecting material and the grid laid together along a heating path, in particular additionally using a, in particular heated or heated, roller h, the connecting material (4) is at least partially liquefied and / or softened and optionally additionally, at least in sections, compressed. For example, the filter material, the bonding material and the grid are laid together over a heated or heated roller promoted. As a result, the connecting material is at least partially liquefied or made to soften. The ironability of the connecting material by means of a heated or heated roll has the additional advantage that no additional, liquid adhesive must be used, which has to cure, which requires curing depending on the liquid adhesive up to several days. The method according to the invention is therefore simpler, faster, cheaper and safer than a conventional method, in which the filter material and the grid material are connected by means of a liquid adhesive which has to harden. The inventive method is also advantageous over a conventional method in which the fusible bonding material has a melting temperature above the melting temperature of the grid or the filter material, since in the method according to the invention neither the lattice material nor the filter material are melted when connecting by means of the bonding material.

"Placed" in the context of the present invention means a planar layers of the filter material, the connecting material and the grid. Preferably, the two-layer grid and the filter material are abutted by means of a deflection roller during transport. Subsequently, the filter material and the two-layer grid pass through the heating path, in particular the heated roller, wherein the grid, the filter material and the bonding material are heated so that only the bonding material is liquefied or softened. For example, after passing through the heating section, the connecting material solidifies, so that a cohesive connection between the grid and the filter material is realized. Alternatively or additionally, melt fibers can be melted between the filter material and the grid when passing through the heating section. Accordingly, the cohesive connection between the grid and the filter material can be realized by the solidification of the melt fibers. Alternatively or additionally, the connecting material can be liquefied or softened by means of an ironing process. Thus, the two-layer grid can for example be ironed onto the filter material by means of heat input and juxtaposition or additionally by compression. The connection therefore advantageously already takes place through the use of the heated roll in one step and requires no additional process step, no additional adhesive and no additional solvents.

In embodiments, in a further step, the filter material, the grid material and the bonding material are pressed together in a contiguous state over the entire surface or in sections. The full-surface or partial compression, for example, with the help of the heated roller. The heated Roller may be formed as a hot roller. By means of a cross-sectionally circular hot roller, for example, a full-surface compression can be realized. The full-surface compression has the advantage that a reliable connection between the grid and the filter material is realized without interruption.

"Sectional compression" means in the present case that only at certain points a compression and / or heating of the connecting material takes place. For example, a roller on the circumference elevations, which are heated, for example, with the help of the surveys, a pressure and optionally heat input can be realized. The pressing in sections can be done, for example, in analogy to an embossing pattern. For this purpose, for example, a heated roller having an embossed pattern can be used. Alternatively or additionally, a pressure and heat input can be realized with the help of thin heated disks. In embodiments, in a further step, the filter material together with the grid and connecting material are folded into a fold pack.

This can be done, for example, in a subsequent step. For example, during folding, the fusible bonding material may have a soft or fluid state. The complete solidification of the connecting material - thus the transition from the melt to the solid after falling below the melting temperature - takes place before the folding.

In embodiments, in a further step, the fold pack is formed into an endless bellows.

Furthermore, a filter medium for a fluid filter, in particular oil or fuel filter, proposed in a motor vehicle. The filter medium comprises a flat filter material, a grid and a fusible connecting material, wherein the fusible connecting material between the filter and the grid is arranged and connects them at least partially cohesively.

In embodiments, the filter material comprises nonwoven material, wherein the grid material and the bonding material comprise a fusible plastic and wherein a melting temperature of the mesh material is higher than a melting temperature of the bonding material. In embodiments, the filter material is formed into an endless bellows. For example, the end faces of the continuous bellows are sealed by means of end plates.

Furthermore, a filter element with a filter medium, as described above, is proposed. In embodiments, the filter element comprises a pleated filter medium, as described above or below, wherein at least partially folding sections are spaced from each other by adjacent struts of the grid.

Further, a motor vehicle with a filter medium, as described above, and / or a filter element, as described above, is proposed.

The filter element is designed in particular as an oil filter or fuel filter. Also conceivable is an embodiment as a filter element for a urea solution.

Further possible implementations of the invention also include not explicitly mentioned combinations of features or method steps described above or below with regard to the exemplary embodiment. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the filter material. The features described for the method apply mutatis mutandis to the filter medium, the filter element and the motor vehicle.

Further embodiments of the invention are the subject of the dependent claims and the embodiments described below. Furthermore, the invention will be explained in more detail by means of embodiments with reference to the accompanying figures.

Brief description of the drawings

It shows: FIG. 1: a schematic side view of a filter medium;

2 shows a schematic perspective view of a filter medium;

3 shows a schematic plan view of a filter medium;

Fig. 4: a section IV of Fig. 2;

5 shows a block diagram of a production method for a filter medium FIG. 6 shows schematically a production method for a filter medium; FIG. 7 shows schematically a further embodiment of a production method for the filter medium; FIG.

8 shows schematically the extrusion of a two-layer grid; and

9 shows a schematic view of a filter medium 1 produced by the method according to FIGS. 5 to 8.

Embodiment (s) of the invention

1 shows a schematic side view of a filter medium 1. The filter medium 1 comprises a flat filter material 2, a grid 3 and a fusible bonding material 4. The fusible bonding material 4 is disposed between the filter material 2 and the grid 3 and connects them at least in sections cohesively. The filter medium 1 comprises a plurality of folds 5, wherein a plurality of contiguous folds 5 forms a fold pack 6. A fold 5 in this case comprises a first folding section 7 and a second folding section 8, wherein the folding sections 7, 8 are connected to one another with the aid of a kink 9. For example, the first fold section 7 is arranged at an angle to the second fold section 8. In this case, an angle 10 between the first fold portion 7 and the second fold portion 8 are present. When reducing the angle 10, the grid 3 prevents the filter material 2 of the first fold section 7 and the filter material 2 of the second fold section 8 from lying flat on one another. Thus, it can be ensured that the filter performance of a fold 5 is reliably ensured during the lifetime of the filter. The grid 3 is a spacer and prevents the juxtaposition of filter material 2 on filter material 2, in particular the collapse of fold sections 7. The spacing allows the fluid, in particular the oil can flow through the pleated filter medium and extends the life of the filter medium. 1

For example, the grid 3 is configured to space two fold sections 7, 8 from one another. The grid 3 may also be referred to as a drainage grid. Preferably, the effect achieved by the grid 3, no stiffening of a fold edge, but a spacing of the filter material 2 in juxtaposition of the fold sections 7, eighth

2 shows a schematic perspective view of the filter medium 1. The grid 3 has webs 1 1, which are arranged such that openings 12 or intermediate spaces between the webs 1 1 are formed. The openings 12 ensure that a fluid can penetrate the filter medium 1.

FIG. 3 shows a plan view of the filter medium 1 from FIG. 2. The webs 11 of the grid 3 are arranged such that a network structure is formed. In this case, four webs 1 1, which are arranged around an opening 12 and connected to each other, form a mesh 13. The mesh 3 is formed from a plurality of meshes 13. Preferably, an opening 12 defines an area of the filter material 2 that is greater than 0.1, 0.2, 0.5 or 1 mm ² . The surfaces 12 have, for example, a quadrangular geometry. The surfaces 12 may be diamond-shaped, parallelogram-shaped or square-shaped. Alternatively, the surfaces 12 may also be oval or round.

4 shows section IV from FIG. 2. The grid 3 has a side 14 which faces the filter material 2. The filter material 2 has a side 15 which faces the grid 3. The connecting material 4 is arranged between the side 14 and the side 15. In this case, the side 14 of the grid 3 is firmly connected to the connecting material 4. Furthermore, the side 15 of the filter material 2 is firmly connected to the bonding material 4. Thus, the bonding material 4 can be seen as a bonding layer or intermediate layer that attaches the mesh 3 to the filter material 2. With the help of the connecting material 4, a material connection between the grid 3 and the filter material 2 is generated. For example, the filter material 2 comprises nonwoven material, wherein the mesh material 3 and the bonding material 4 comprise a fusible plastic and wherein a melting temperature of the mesh material 3 is higher than a melting temperature of the bonding material 4. In this case, the mesh material 3 and the bonding material 4 as a coextruded body, which is formed in one piece, are present. In this case, the composite of grid material 3 and connecting material 4 is formed with the coextrusion. The connection between the filter material 2 and the connecting material 4 is formed by a melting of the connecting material 4 and a solidification of the same. For example, the molten bonding material 4 may partly penetrate into the filter material 2. Alternatively, the bonding material 4 may also be present as melt fibers 30, which are applied to the filter material 2. For example, an application of the fusible fibers 30 to the filter material 2 and / or incorporation of the fusible fibers 30 in the Filter material 2 possible. Thus, a fusion between the grid 3 and the filter material 2 is formed by the melting and solidification of the melt fibers 30.

Alternatively, the bonding material 4 may also be in the form of a sprayed-on layer which is sprayed onto the side 14 of the grid 3 and / or onto the side 15 of the filter material 2. After spraying, the filter material 2 and the grid 3 may be brought together such that the bonding material 4 is interposed therebetween. In this case, the connecting material 4 may have a liquid, thermoplastic or soft state when the grid 3 and the filter material 2 are brought together, so that after solidification of the connecting material 4 there is a material connection between the grid 3 and the filter material 2. Alternatively, the sprayed-on bonding material 4 solidify before the joining process, wherein the material connection between the grid 3 and the filter material 2 is realized by a further melting and solidification process.

5 shows a flowchart of a method for producing the filter medium 1. The method comprises the steps of providing S1 of the sheet filter material 2; providing S2 of the grid 3; arranging S3 the fusible bonding material 4 between the filter material 2 and the grid 3, wherein the fusible bonding material 4 is applied to the grid and / or applied to the filter material 2; a thermal liquefaction or softening S4 of the bonding material 4, wherein a melting temperature of the bonding material 4 is lower than a melting temperature of the mesh material 3; a juxtaposition of the filter material 2 and the grid 3, wherein the juxtaposition can take place before, during or after the thermal liquefaction or softening (the juxtaposition can thus take place as part of step S3 and / or step S4) and a solidification S5 of the connecting material 4.

The provision S1 of the sheet-like filter material 2, the provision S2 of the grid 3 and the placing S3 of the fusible connecting material 4 between the filter material 2 and the grid 3 preferably take place before the thermal liquefaction or softening S4 of the connecting material 4. After the thermal liquefaction or softening S4 must solidify the bonding material 4 S5 to connect the grid 3 with the filter material 2.

For example, an optional step (shown in dashed lines) of the full-surface or sectional compression S6 of the filter material 2, the grid material 3 and the bonding material 4 in an abutted state. This compression S6 may occur during or after the thermal liquefaction or softening S4.

Furthermore, after the thermal liquefaction or softening S4 and during or after the solidification S5 of the bonding material 4 or after the compression S6, optionally a folding S7 of the filter material 2 together with the mesh 3 and bonding material 4 into a fold pack 6 can take place. An optional processing S8 of the filter medium 1 to a filter element 23 can take place after the folding S7 or during the folding S7. After the step S8 of the processing of the filter medium 1, the filter element 23 is present, the filter element 23 comprising a filter medium 2 with a grid 3. The filter medium 2 is folded into a fold pack 6, wherein the grid 3 adjacent fold sections 7, 8 of the fold pack 6 spaced from each other to counteract adherence of the fold sections 7, 8, in particular at a pressure drop within the filter element 23. Steps S1 to S8 are not exclusively to be performed sequentially (as shown in FIG. 8). Rather, several of the steps S1 to S8 can take place in parallel; in particular, the steps of thermal liquefaction or softening S4 and of compression S6 can be carried out sequentially or in parallel, the parallel flow being preferred. Steps S4 and S6 may elapse before step S5. FIG. 6 shows a schematic sequence of the method for producing the filter medium 1. In this case, in step S1, the filter material 2 is rolled up into a roll 24.

In step S2, the grid 3 and the bonding material 4 are provided as extruded two-layer grid 25. The two-layer grid 25 is rolled up into a roll 21 and is provided as a roll 21.

In step S3, the two-layer grid 25 and the filter material 2 by means of a guide roller 26 are juxtaposed and conveyed to a heated roller 27.

The step S4 is performed by means of a pass around the heated roller 27, wherein the heated roller 27 causes a heat input into the filter material 2, the grid 3 and the bonding material 4, so that melting or softening of the bonding material 4 is realized. Optionally, during step S4 with the aid of the heated roller 27, the step S6 of the full-surface compression can be carried out. sens the filter material 2, the grid 3 and the connecting material 4 done. By means of the thermal liquefaction or softening S4 of the bonding material 4 and of the compression S6, a sufficient wetting of the filter material 2 by the molten or softened bonding material 4 is ensured. The filter material 2, the grid 3 and the connecting material 4 are arranged as shown in Fig. 4.

Subsequently, the filter material 2, the grid 3 and the connecting material 4 can be supplied to a folding device 29 for carrying out the step S7 by means of a further deflection roller 28. The step S5 of solidifying the bonding material 4 to form a material bond between the grid 3 and the filter material 2 by means of the bonding material 4 can be completed before reaching the folding device 29, during the folding process S7 or after the folding process S7. Preferably, the folding device 29 is designed as a stamping folding system. After the step S7, the filter medium 1 has a plurality of pleats 5 as shown in FIG.

Alternatively, instead of the two-layer grid 25, the grid 3 may be provided without the bonding material 4, wherein on the filter material 2 melt fibers 30 are applied.

As a further alternative, the connecting material 4 can be sprayed onto the grid 3 during unrolling of the grid or sprayed onto the filter material 2 during unrolling of the filter material (indicated by arrows 22).

The bonding material 4 and the mesh material 3 comprise fusible plastic, wherein a melting temperature of the mesh material 3 is higher than a melting temperature of the bonding material 4. In contrast to FIG. 6, FIG. 7 schematically shows a manufacturing process in which the two-layer grid 25 in step S3 and the filter material 2 by means of two pulleys 31, 32 are brought together and brought together.

After passing through the deflection rollers 31, 32, the filter material 2, the grid 3 and the connecting material 4 are placed side by side two rollers 33, 34, wherein the steps S4, S6 are performed by means of rollers 33, 34, the sections a heat and pressure entry in the filter material 2, grid 3 and 4 introduce compound material. Thus, the bonding material 4 is partially melted S4, so that after the step S5 of solidification of the bonding material 4, the filter material 2 and the grid 3 are only partially joined materially together. For example, one or both of the rollers 33, 34 may have elevations 35 that can exert partial pressure on the filter material 2, the grid 3 and the connecting material 4. In this case, the roller 33, 34 can be heated either completely or only at the elevations 35. The partial cohesive bonding of the filter material 2 to the grid 3 has the advantage that there are fewer areas of the filter material 2 that are adhesively bonded by the connecting material 4 and thus the filter effect is less impaired. FIG. 8 schematically shows a manufacturing process of a two-layer grating 25 which can be used for the manufacturing processes as shown in FIGS. 6 and 7. In this case, a raw material 36 of the connecting material 4 is provided and liquefied in an extruder 37. Furthermore, a raw material 38 of the grid 3 is liquefied in an extruder 39. The raw materials 36 and 38 are supplied to a channel 40, 41, respectively. The channels 40, 41 are connected to a channel, so that the liquefied raw materials 36, 38 are brought together accordingly. During this merging, the forming grid material 3 and the forming connecting material 4 are bonded together in a material-locking manner. The mesh material 3 and the bonding material 4 are layered. The channels 40, 41 are arranged, for example, in a die 42. Furthermore, for example, a grid tool 43 is connected to the die 42. After passing through the die 42, the interconnected layers of bonding material 4 and grid material 3 are fed to the grid tool 43. The grid tool 43 converts the two layers of bonding material 4 and grid material 3 such that a corresponding two-layer grid 25 leaves the grid tool 43. The coextrusion can also be called, for example, bi-extrusion.

Alternatively, the bonding material 4 may be extruded onto the mesh material 3 or the mesh material 3 onto the bonding material 4.

By providing the two-layer grid 25 and applying the same to the filter material 2, as shown in FIGS. 6 and 7, steps S1, S2 and S3 are realized.

9 shows a schematic view of a filter medium 1 produced by the method according to FIGS. 5 to 8. The filter material 2 and the grid 3 are zigzag-shaped folded and the fusible bonding material 4 is located between the filter material 2 and the grid 3 and connects them. The filter material 2 and the grid 3 are connected to each other by cohesive thermal joining. The grid 3 gives the filter material 2 mechanical stability and keeps the folds of the Filtermateri- as 2 at a distance from each other, so that the drainage of a fluid to be filtered, in particular oil, can be done optimally. Characterized in that the grid 3 and / or the filter material 2 by means of the fusible bonding material 4 by means of heat input and Aneinanderlegens or additionally by compression are firmly bonded together, wherein the fusible bonding material 4 is a melting temperature below the grid 3 and the filter material 2, the filter pores are not closed by excess adhesive material or bonding material, or the thickness of the mesh 3 is not reduced by the heating. The method according to the invention thus makes possible a high-quality weld seam without completely melting through the grid 3 and / or the filter material 2. The drainage function of the filter medium can be used optimally and the flow R can be optimally carried out by the folds of the filter medium shown.

Claims

claims

1 . Method for producing a filter medium (1) for a fluid filter, in particular in a motor vehicle, with the steps:

- Providing (S1) a flat filter material (2);

- providing (S2) a grid (3);

- placing (S3) a fusible bonding material (4) between the filter material (2) and the grid (3), wherein the fusible bonding material (4) is applied to the grid and / or applied to the filter material (2);

- thermal liquefaction or softening (S4) of the bonding material (4), wherein a melting temperature of the bonding material (4) is lower than a melting temperature of the mesh material (3);

- juxtaposition (S3 and / or S4) of the filter material (2) and the grid (3), wherein the juxtaposition can occur before, during or after the thermal liquefaction or softening;

- solidifying (S5) the joining material (4) to form a material connection between the grid (3) and the filter material (2) by means of the joining material (4).

2. The method of claim 1, wherein the melting temperature of the grid (3) is equal to or higher than the melting temperature of the filter material (2).

3. The method of claim 1 or 2, wherein the grid (3) and the bonding material (4) to a two-layer grid (25) extruded, in particular coextruded, are.

4. The method of claim 1 to 3, wherein the filter material (2) and the fusible bonding material (4) extruded, in particular coextruded, are.

5. The method of claim 4, wherein the bonding material (4) and the filter material (2) are formed as a core-sheath fiber, wherein the filter material (2) the core and the bonding material (4) the sheath of the core-sheath fiber forms.

6. The method according to any one of claims 1-5, wherein the connecting material (4) on the grid (3) and / or the filter material (2) is sprayed.

7. The method according to any one of claims 1-6, further comprising the step of the full-surface or sectional compression (S6) of the filter material (2), the grid material (3) and the connecting material (4) in the joined state.

8. The method according to any one of claims 1-7, wherein the filter material (2), the connecting material (4) and the grid (3) abutting each other are conveyed along a heating path and thereby the connecting material (4) at least partially liquefied and / or softened ,

9. The method of claim 8, wherein the filter material (2), the connecting material (4) and the grid (3) juxtaposed and using a, in particular heated or heated roller (27, 33, 34) are conveyed along the heating section and thereby the connecting material (4) at least partially liquefied and / or softened and in addition, at least in sections, is compressed.

10. The method according to any one of claims 1-9, further comprising the step of folding (S7) of the filter material (2) together with grid (3) and connecting material (4) to a fold pack (6).

1 1. Method according to one of the preceding claims, wherein the steps (S4) and (S6) are carried out in parallel.

12. The method according to any one of the preceding claims, wherein the fusible bonding material (4) is a thermoplastic.

13. The method of claim 12, wherein the fusible bonding material (4) is a thermoplastic from the group of polyolefins, polyamides or polyesters.

14. Filter medium (1) with a flat filter material (2), a grid (3) and a fusible bonding material (4), wherein the fusible bonding material (4) has a lower melting point than the grid (3), wherein the fusible bonding material ( 4) between the filter material (2) and the grid (3) is arranged and this connects at least partially cohesively.

15. Filter medium (1) according to claim 14, wherein the melting point of the grid (3) is equal to or higher than the melting point of the filter material (2).

16. Filter mediunn (1) according to claim 14 or 15, wherein the grid (3) and / or the filter- material (2) with the fusible bonding material (4) extruded, in particular coextruded, in particular, the filter material (2) as Core-sheath fiber formed, wherein the filter material (2) the core and the connecting material (4) forms the sheath of the core-sheath fiber and / or the grid (3) is formed as a two-layer grid (25).

17. Filter medium according to claim 14 or 15, wherein the fusible bonding material (4) on the grid (3) and / or the filter material (2) is sprayed.

18. Filter medium (1) according to one of the preceding claims, wherein the fusible bonding material (4) is a thermoplastic.

19. Filter medium (1) prepared by a process according to claims 1 to 13.

20. Filter element with a filter medium (1) according to one of claims 14 to 18 or according to claim 19.