EP2665539A1

EP2665539A1 - Filter element having at least one mat-type or sheet-type filter web

Info

Publication number: EP2665539A1
Application number: EP12700608.8A
Authority: EP
Inventors: Micha Kreibig
Original assignee: Hydac Filtertechnik GmbH
Current assignee: Hydac Filtertechnik GmbH
Priority date: 2011-01-18
Filing date: 2012-01-17
Publication date: 2013-11-27
Also published as: CN103402600A; DE102011009325B4; WO2012097973A1; US9962639B2; CN103402600B; US20130306548A1; DE102011009325A1

Abstract

A filter element is disclosed having at least one mat-type or sheet-type filter web (3), which forms by its outside (5) at least in part a filter jacket (7) that is closed on the peripheral side, wherein along the outside (5) of the filter jacket (7) a surface configuration or modification takes place in such a manner that structures (11) that are delimited from the remaining surface (9) of the filter web (3), are joined to the filter jacket (7) and are of presentable contour and/or thickness are created, wherein the structures (11) are generated by spray-fibre application and shaping, in such a manner that in time sequence, first the structures (11) and then the filter jacket (7), or in reverse order in time sequence, first the filter jacket (7) and then the structures (11), or that simultaneously both the filter jacket (7) and the structures (11) are formed in negative or positive shape on the filter jacket (7). In addition, the production of the filter element and also a shaping device used in this production process are disclosed.

Description

Filter element with at least one mat or layered filter web

The invention relates to a filter element with at least one mat or layer-shaped filter web, which at least partially forms a circumferentially closed filter casing with its outside, wherein along the outside of the filter shell such a surface design or modification takes place that delimited from the other surface of the filter web, with the filter jacket connected structures of specifiable contour and / or density are created.

Filter elements for filtering gaseous and liquid fluids are freely available on the market in a variety of embodiments. The filter elements mentioned are used in a filter housing fed fed, loaded with dirt particles fluid, for example in the form of a hydraulic medium, through the use of a mat or layered filter web and cleans the thus cleaned fluid from the filter housing in the fluid, in particular in one Hydraulic circuit due. Basically, the reliability of such hydraulic circuits and the components incorporated therein depends to a great extent on the perfect condition of the respective fluids moving therein. For higher-value installations in particular, it is therefore necessary, for economic reasons, to provide suitable filter devices for the media and fluids in question in order drove impurities safely to eliminate. It is generally known to assemble mat or layered filter webs of various filter materials in the filter elements mentioned, to fold or to pleat them, at least in area areas, to produce folded or pleated filter mats, which are laid in particular around a support tube provided with passages. Such filter elements have to protect against damage on their outer circumference suitable protective devices, such as a fine-meshed wire mesh, which follows in particular the fold course of the filter mat on. Instead of fine-meshed wire cloth, it is also known to lay fiber structures, such as textile tapes, around the outer circumference of such a filter element in order thus to obtain protection against damage to the mat-shaped or layered, folded or pleated filter mats. The connection of the filter mat with the mentioned wire mesh or with textile tapes is complicated and expensive and does not guarantee in any case a protection of the filter mat from mechanical damage. Such additionally applied protective devices also tend to detach or delaminate, especially when the direction of flow of fluid on the said filter element is reversed, for example during a backflow process. The known protective devices, such as the mentioned wire mesh or textile fiber structures, such as tapes, also have the disadvantage that their flow and filtration properties in comparison to the sensitive filter materials made of polyester, glass fiber or paper non-woven are very different and sometimes worse. From a defined pre-filter effect sol- rather protective devices can hardly be spoken in the rule.

DE 10 2005 014 360 A1 shows and describes a filter element with a filter material folded in a star shape, has individual filter folds, at least partially arranged in the distance between two adjacent filter folds on the inner peripheral side or outer peripheral side to the filter folds, extends at least one fluid-permeable support means. The Supporting agent is provided in particular with filter-active substances or itself composed of these filter-active substances and can be used as a filter aid. The fluid-permeable support means in particular has a basic structure in the manner of a support tube, which surrounds the filter material of the filter element on the inside or outside circumference side. In the basic structure filter aids, such as bentonites, pearlite, activated carbon, diatomaceous earth and the like are embedded, which are able, as filter-active substances to prevent silting of the filter element in such a way that fluid or component-damaging components are reliably separated in the fluid ,

WO 01/37969 shows and describes a fastening tape, in particular in the form of an adhesive tape, which can be wrapped around a pleated filter medium and thus to stabilize individual filter pleats of the pleated filter medium in their predeterminable distance from each other and set. This permanently ensures the provision of a predefined filter surface of the filter medium. However, a prefiltration with this known solution is not possible. These known filter elements are characterized in particular by the fact that each functionality imprinted on them is realized by a manufacturing or working step by individual components, which is not optimal in terms of its production time or its use of materials. DE 693 16 647 T2 discloses a filter element with a porous, thick-walled, one-piece, self-supporting, resin-impregnated and bonded fibrous, tubular filter structure, which comprises:

a hollow core;

an inner shell of a first large pore porous medium adjacent to the hollow core; and an outer sleeve of a second small pore porous medium which is finer pored than the first porous medium and adjacent to the inner sleeve, the first and second porous media being resin impregnated and bonded, and wherein fluid to be filtered in operation passes radially inward the tubular filter structure flows.

In order to provide an increase in the quality level of this known filter element, an incrementally stepped porosity is provided in such a way that the pores on the outside of the filter element are the most numerous, where their dimensions are chosen to be smallest. Preferably, it is provided to introduce depressions as structures on the outside of the filter element and therefore in the outer filter jacket, which then represent themselves along the filter element longitudinal axis as individual rings running parallel to each other.

To make the known filter element, a fibrous material is mixed with water or other suitable dispersing agent to form a slurry. Thereafter, one or more perforated tiles or dies are immersed in the slurry in a felting tank containing an aqueous fiber dispersion and by applying a vacuum to the interior of the tiles, the fibers are simultaneously and uniformly "grown" onto the tiles, in order thus to form the structured outer contour of the filter jacket, the known annular structures appearing as recesses in the filter jacket and thus in negative form, and already imparting a specific functionality is not possible due to the uniform density profile of the respective structure until an adequate fiber volume has been grown by slurrying and otherwise the slurry process On a regular basis can only be implemented in a complex manner, starting from this prior art, the invention has the task, while maintaining the advantages of the known solution, such as a high filter stability and filter quality to ensure that they further improve that, in particular Regarding the production time and the use of materials an optimal filter element production is possible as well as a largely free influencing of the filter functionality.

According to the invention this object is achieved by a filter element with the features of claim 1 in its entirety, as well as by a molding apparatus according to claim 20 and a method according to claim 25.

Characterized in that according to the characterizing part of claim 1, the structures are produced by Sprühfaserauftrag and shaping such that in chronological order first the structures and subsequently the filter jacket or in reverse temporal order first the filter jacket and then the structures or at the same time both the filter jacket as If the structures in negative or positive form also form on the filter jacket, a simplified production of the filter element according to the invention in a cost-effective manner compared with the slurry method described above for forming the structures is achieved.

By spraying fiber application by means of a suitable nozzle applicator and the aforementioned shaping, at least the outer side of the filter element, which is constructed from a mat or layered filter web or several such webs, can make such a surface design or surface modification that of the remaining surface of the filter jacket Spatially delimited structures of a varying, predefinable contour and / or density are created on the filter web, so that the outside in the sense of a functional surface structuring learns, the various functionalities, such as areas of increased strength, areas with deposits of filter aids, areas with different fluid guiding properties or areas with specific optical properties and the like allows more. The targeted introduction of fiber material by means of a spray application process in the respective prepared mold surface creates a molding process in which in contrast to the known Aufschlämm process specifically the application of the fibers can be controlled in the mold, so that a very wide range of different filter elements, which differ in their functionality. It is provided either as a recess first to produce the outer filter casing by the Sprühfaserauftragverfahren in the mold and then temporally following the respective negative internal structure, which depending on the configuration of the manufacturing process of dahinge- this process can also be reversed in time, so that the first positive projecting structure is formed and then in time the outer filter shell. The demarcation between the filter casing and the structure can be seen in the fact that the filter casing should in principle occupy the larger or at least the same surface with respect to the particular structure to be applied or applied. If a plurality of spray nozzles of the molding apparatus are used for the application of fibers, it is also possible to have structure and fiber material emerge simultaneously, at least in some areas. The arranged on the outside of the filter mantle structures specifiable contour and / or density are designed in a particularly advantageous embodiment of the filter element such that the structures the flow and / or the flow of fluid through the filter element, in particular through the filter jacket, in the At least partially determine or influence the type of flow-directing elements. The structures of predeterminable contour are thus able to decisively influence the type of fluid flow to take on the filter element, to the effect that a structurally desired flow direction and speed of the fluid flow and also the basic type of flow and flow through the filter element - turbulent or laminar - can be adjusted. In particular, if the structures have an increased density in comparison to the remaining density of the mat or layered filter web, they can be used to stiffen the filter jacket at least partially. As a result, in particular the introduction or arrangement of additional stiffening elements on the filter casing is unnecessary for the purpose of increasing, for example, the buckling stiffness of the filter casing.

It may also be advantageous to use the structures of predeterminable contour and / or density on the outside of the filter web for forming image, in particular numerical or alphanumeric elements, such as trade marks and the like. The structures may hereby be depressions or elevations, which represent a trade mark for the filter element, wherein the depressions or elevations may form surfaces or lines for a subsequent printing of the structures. It is expedient to form the structures specifiable contour and / or density in particular for stiffening purposes of the filter element or for purposes of fluid management on the outside of the filter web linear or strip-like. In this case, these line or strip-like structures can extend tangentially over the outside of the filter jacket or can also extend substantially axially to the filter jacket. It may also be advantageous to align the line- or strip-like structures at least predominantly in the radial direction of the filter element on the outside of the filter web. The line- or strip-like structures, which, as mentioned, can extend radially and / or tangentially and / or axially, may also have interruptions in their contour or in their orientation. In a particularly preferred embodiment of the invention terelements have the line or strip-like structures on the outside of the filter jacket preferably constant selected distance from each other. It is understood that in particular for the representation of pictorial symbols by the line or strip-like structures, these can also intersect. However, it may be advantageous to the line or strip-like structures S-shaped curved or jagged form in its course. In principle, any other geometric design of the plan or the transverse or longitudinal section of the structures is possible, so that it may be advantageous to form the structures disc or circular and this particular as disc or circular elevations or depressions on the surface of the filter shell train. The outside of the filter jacket can in this case be both the inflow and the outflow side of the filter element. Preferably, the structures of predeterminable contour and / or density are an integral part of the filter web and the outside of the filter web, but it may also be advantageous to form the structures partially or completely as attached components of the filter web. To minimize the production costs of the filter element, it is in any case advantageous to form the structures of individual fibers from which also preferably the filter web, at least partially, is formed. It is understood that, in addition to the filter web thus formed, depending on the intended use of the filter element, one or more further filter layers with or without support grid or other support means can form the filter element, so that overall a multilayer structure of the filter element can result. In particular, this allows a structurally predetermined and desired adjustment of the filtration of the fluid as it flows through the filter element with respect to filter fineness, through-flow direction of the filter element and the effect of filter aids on the fluid to be filtered effect (parameterization). In a particularly preferred embodiment, the filter element with its filter web and any further filter layers and support grids is guided around a flow-through support tube in the manner of a cylindrical hollow element, so that an integrally formed filter element is thus formed as a replacement part for a filter housing in a hydraulic system. All components of the filter element mentioned above, in particular the filter web according to the invention, can hereby be defined between two end caps of the hollow element, so that a handleable structural unit or tradeable structural units with differing structures of definable contour and / or density can be formed on the surface of a filter jacket can.

In order to minimize the manufacturing and in particular assembly costs of a filter element provided with the structures according to the invention, a mold device for producing the filter element is proposed, which comprises a mold, whose mold surface the delimited structures, but at least the spatial boundary of the structures, for the filter jacket of the Fitlerelements having the nature of a positive or negative matrix. The mold surface thus formed is thus able to form the outside of the filter mantle in the sense of a moldable from it Negativbzw. To get positive design. It is advantageous, in particular in the case of a complex overall shape of the filter element, to form the mold from at least two equally sized mold halves, the mold halves joining together at least partially defining the delimited structures for the surface of the filter web. To produce a filter element in a tubular shape, it is thus also advantageous to form the shape tubular and on the inside of the mold, especially exclusively on the surface of the inside of the mold, the respective matrix for creating the delimited structures of predeterminable contour and / or density for the To arrange filter web. Such a shape designed with a free space or a preferably cylindrical cavity defined by the mold is particularly suitable for forming a spunbonded nonwoven on its inside with the aid of a nozzle device with spinnerets, from which a plastic melt can be formed into individual fibers or threads the filter web and the filter web itself essentially forms to apply. The nozzle device can be formed, for example, in the case of a substantially cylindrically formed shape as a nozzle lancet or nozzle beam with a lining in the axial and / or radial direction of spinnerets with a distance defined to one another. In this way, and provided that the surface of the mold has self-releasing properties with respect to the applied fibers, a seamless layer or seam may be formed by a continuous and continuous fiber application in the axial and / or radial direction to the mold.

Due to their adjustable fiber thickness, the fibers are very thin and thus suitable for enabling a multi-layer continuous application of fibers or threads formed from plastic melt (thermoplastic). The fibers or filaments applied in the plastic state are applied to the inside of the mold and the mold components arranged therein in the manner of a negative matrix to form the delimited structures of predeterminable contour and / or density for the filter web, wherein after a cooling and / or curing process of the fibers or filaments the delimited structures are permanently formed on the surface of the filter web. The pertinent nozzle device makes it possible, in particular, to select the amount of fiber or thread locally applied over the inside of the mold and thus also the constructively desired adjustment of the density of the filter web, in particular in the region of the delimited structures. It is understood that this results in regions of different strength and / or loading rich different filter fineness over the entire filter web. Overall, can be produced by the inventive method in a simple manner a predetermined in any limits layer thickness of the surface of the filter element forming filter web material.

It may be advantageous to choose the layer thickness between about 2 mm and 6 mm. In order to be able to use the filter web produced according to the invention in particular as a prefilter for the filter element, it is advantageous to vary the layer thickness or the fiber density of the fibers or filaments applied to the inside of the mold in the manner proposed over the thickness of the filter web. So it is possible, for example, to choose the fiber density on the upstream side of the filter web less than on the downstream side of the filter web. In this proposed manner can be a total of a one-piece filter sheet form, which alone forms a filter element. After cooling and solidification of the fibers or threads in the mold, the filter element can be removed in particular by dissolving the two or a plurality of moldings from the mold and these are reused for a re-manufacturing process of a filter element according to the invention. It is understood that before applying a new filter sheet in the form to clean them and / or to be treated with release agent on its surface.

With the method according to the invention for producing the delimited structures of predeterminable contour and / or density and the filter mantle, filter elements can be formed which require no further post-processing, in particular no processing of the edge seam.

The invention is explained in more detail with reference to the drawing. It shows in principle and not to scale representation of the 1 shows a perspective view of a filter element according to the invention with fiber cladding;

Fig. 2 is a perspective view of a molding apparatus for producing a filter element comparable to the solution according to the

Fig.1;

3a shows a perspective view of a mold half of a mold for

Production of a further embodiment of a filter element;

FIG. 3b is a perspective view of one of two mold halves as shown in FIG. 3a; FIG. 4a is a perspective view of another embodiment of a mold half for producing a filter element;

Figure 4b is a perspective view of a mold formed from two equal-sized mold halves as shown in Figure 4a; and

5 to 8 further embodiments relating to a perspective

View of a mold half for the production of differently shaped filter elements.

1 shows a schematic, perspective view of a filter element 1, as it is used, for example, in suction filters or line filters for the depth filtration of a gaseous or liquid fluid. The filter element 1 is formed as a hollow cylinder with over its axial length approximately the same outer and inner diameter. The filter element 1 is produced in a spray application method (spun spray method) from 2, which are applied to an inner side 41 of a mold 29 by means of a nozzle device 39 by means of a coating method of a plastic melt shown in FIG. The filter element 1 is thus formed as a one-piece, produced by a continuous application of individual fibers 23 on a mold surface 31 of the mold 29 component. The individual fibers are arranged chaotically or in regular order over the thickness of the entire filter element. The filter element 1 has a filter web 3, which is formed in the manner mentioned as a fiber mat of individual fibers 23 and whose outer side 5 in the illustrated Ausführungsbei- game in Fig.l the inflow side 22 forms to be cleaned fluid of the filter element 1. The filter web 3 forms a circumferentially closed, around the entire Fi lterelement 1 reaching filter casing. 7

As FIG. 1 further shows, the filter element 1 is constructed by stacking a total of three filter layers 25, of which the filter web 3 forms the outermost filter layer. In the exemplary embodiment shown in FIG. 1, the individual filter layers 25 have a layer thickness S of approximately 2 mm to 4 mm in each case. A surface 9 of the filter web 3, arranged around the circumference of the filter web 3, shows a demarcated positively projecting structure 11 formed as an image symbol 15. The icon 15 or the demarcated structure 1 1 is arranged over the entire axial length of the filter element 1 at defined distances a to each other. The filter sheet 3 and the image 1 5 are made of the same material, namely a thermoplastic such as polyamide, polypropylene, polyacrylic or the like and made in a single procedural font. In this case, the density of the selected fiber material within the icon 1 5 and within the filter web 3 is not fundamentally different. The image characters 15 or the demarcated structure has a greater geodesic height than the rest of the outside 5 of the filter web 3. The image character 1 5 can be lifted by means of a simple printing process color of the surface 9 of the filter sheet 3. This requires For example, only the rolling of the outer side 5 of the filter element 1 on a straight, flat carrier dye for printing the icon 1 5. As the Figure 1 further shows, the filter element 1 has a further radially inner filter layer, which has a greater filtration fineness has the filter web 3. The further inner filter layer 25a is, as well as the adjacent radially further inner filter layer 25b, formed in a process step with the filter web 3, in a so-called spun-spray process. The individual fibers 23 of the respective filter layers 25a and 25b lie chaotically one above the other, as is the case with the filter layer 25 or with the filter web 3, wherein the filter fineness of the filter layer 25 is greatest of all three filter layers shown. Fluid 13, for example a hydraulic oil, is guided in the operation of the filter element 1 by fluid-carrying means within a filter housing (not shown), in which the filter element 1 is housed, to the inflow side 22 of the filter element 1 and penetrates the filter layers 25 to 25 b, after Passage of a support tube, not shown in the interior of the filter element 1 at its outflow side 22 'from the filter element 1 escape th and cleaned cleaned to be supplied to a hydraulic circuit. However, the filter element 1 can also be formed only from a peripheral layer of individual fibers.

FIG. 2 shows, in an embodiment shown only by way of example, a forming device 27 for producing a filter element 1, as shown in FIG. In principle, the molding device 27 has two essential components, namely a hollow-cylindrical mold 29 formed from two equal-sized mold halves 35, and the nozzle device 39. The mold halves 35 are simplified as thick-walled cylinder halves, in which, for example, a cooling device can be arranged to cool its inner side 41 formed. The mold halves 35 are provided with suitable fixing facilities, which are not shown in detail, provided to connect them without offset to each other but positively releasable together.

The inner side 41 of the mold halves 35 has a self-separating property with respect to the material of the filter web 3. In the surface 43 of the inner side 41 of each mold half 35, a negative matrix 33, which images the image symbol 1 5 shown in FIG. 1 on the filter web 3 in a mirror image, is introduced in the manner of cutouts or other recesses. In the viewing direction of FIG. 2, the matrix 33 is formed on the right by the icons 15, such that the icons 15 in FIG. 1 are mirror-image recesses 45 in the mold surface 31 or surface 43 of the inside 41 of each mold half 35. The matrix 33 is formed in the viewing direction of Fig.2 left by circular disc-shaped recesses 21, also in the form of over the entire region of the wells 21 reaching, equally deep recesses. As shown, the two mold halves 35 thus form a hollow cylinder, so that a cylindrical free space 37 results in the radial direction between the mold halves 35. The nozzle device 39 is essentially formed by a nozzle bar 40 made of a plastic melt 47 transporting tube 49. On the nozzle bar 40 spinnerets 51 are arranged to form the individual fibers 23 at regular intervals. The nozzle openings 53 of the spinnerets 51 in the embodiment shown form the individual fibers 23 hydraulically by applying pressure to the plastic melt 47 and align the fibers approximately perpendicular to the surface 43 of the inner side 41 in each mold half 35 for the spray application. The nozzle bar 40 is moved in the axial direction of the mold 29 by a servomotor device, not shown, wherein the axial movement is superimposed by a rotational movement of the nozzle bar 40, so that the individual fibers 23 are sprayed chaotically onto the surface 43 become. It may be advantageous to use a carrier air flow for better fanning out the plastic melt jet and for transporting the individual fibers 23 to the surface 43. In a single process, therefore, the structures 1 1 and all filter layers 25, 25 a, 25 b, and thus also the filter web 3, which carries the structures 1 1 on its outer side 5, are formed by applying the individual fibers 23 in the manner mentioned. Alternatively or additionally, the mold may also move relative to the nozzle bar 40.

After complete application of the individual fibers 23 and the formation of the desired filter layers and after a solidification or solidification process of the filter layers 25, 25a, 25b, the mold halves 35 shown can be radially moved apart after loosening the corresponding form-fitting and performing a centering connection and the filter element 1 are removed , The filter element 1 is characterized by a sufficient rigidity in relation to its intended use, wherein the further figures show measures, inter alia, to improve the rigidity of the filter element 1. For example, FIG. 3a shows, in a schematic, perspective view, a mold half 35, on the inside surface 43 of which spirally extending, slightly inclined recesses 45 having a constant, rectangular cross-section are embedded in the surface 43.

The recesses 45 in the manner of lines or strips have the same, axial distance from each other, so that they, as shown in Fig. 3b in a further perspective view of a mold 29, form an endless, circumferential spiral shape when the mold halves 35 are moved together. If, in a production method as shown in FIG. 2, a filter element 1 is produced by application of individual fibers 23 in the described manner. The result is a filter element 1 whose outer side 5 of its filter web 3 has a surface 9 which has a spiral 55 projecting radially out of its surface 9. The spiral 55 formed in this way represents a delimited structure 1 1, which is able to contribute both to the radial and / or axial stiffening of the filter element 1 and to the fluid guidance on its surface 9. Incidentally, the same reference numerals apply to the same components as in the preceding figures.

The shape can also be formed in one piece, for example, consist of a hollow cylindrical injection mold and the filter element can be removed accordingly due to its flexibility from the mold. Also, a removal of the filter element can be achieved by destroying the mold. As shown in FIGS. 4 a and 4 b, recesses 45 can be introduced into the surface 43 of the inner side 41 of each mold half 35 of the mold 1 for the production of delimited structures 11 on the upper side 9 of a filter element 1, also in the form of rectangular grooves , The recesses 45, which are shown in FIGS. 4 a and 4 b, each extend at an acute angle to one another substantially radially to each mold half 35 and intersect tangentially approximately in the center of each inner side 41 of each mold half 35, so that Overall, as shown in FIG. 4b, the recesses 45 form a winding shape. Accordingly, when a filter element is produced in the mold 29 shown in FIG. 4b, a structure 11 is formed on the surface 9 of the filter web 3 of the relevant filter element 1, which has an intersecting strip-like shape. A pertinent structure 1 1 serves primarily the axial and radial stiffening of the filter element. 1 5 shows in a further perspective, schematic view of a mold half 35 for a mold for producing a filter element. 1 a further embodiment possibility of the surface 43 on the inside 41 of the respective mold half 35. Here are regularly axially extending recesses 45 shown over the axial length constant, rectangular cross-section. These longitudinal paths 57 represent a negative matrix 33 which, after the formation of a filter element in the pertinent form, forms longitudinal webs on the surface of the filter element, which webs are arranged around the circumference of the filter element 1 at a constant, tangential distance. This results in particular in an improved buckling and bending stiffness of the relevant filter element 1. In addition, rectangular fluid guide channels on the upstream side are formed between the structures 1 1 formed as a longitudinal webs of a filter element 1 originating from the mold half or from the mold 29 22 of a pertinent filter element 1. Thus, with a design of the mold in the manner as shown in Figure 5, a longitudinal guide of the inflowing to the filter element 1 fluid 13 along the outside 5 of the filter web 3 is supported.

As FIG. 6 shows in a further perspective, schematic view of a mold half 35 of a further embodiment of a mold 29, the recesses 45 on the surface 43 of the inner side 41 of the relevant mold half 35 can also be S-shaped in their ground plan form. It may also be advantageous, as shown in FIG. 7, to make the recesses 45 jagged in their plan view. The embodiment of a mold half 35 shown in FIG. 6 provides a surface 9 of the filter web 3 of a filter element 1 formed therefrom which is capable of slowing fluid 13 passing through it and laminar flow on the filter element 1 in its flow form. The changes in direction 19 of the structures 11 formed during the formation of a filter element from the shape shown in FIG. 7 can contribute to a turbulence formation and slowing down of a fluid flow at the surface 9 of the filter web 3. 8 shows a further schematic, perspective view of a mold half 35 for a mold 29 for forming a filter element 1, the surface 43 of which has line-like, circular disk-shaped recesses with a constant, over the entire surface of the respective recess 45 constant depth of engagement. The circular disk-shaped recesses 45 have constant axial distances a to each other, so that form in a formation of a filter element 1 from the pertinent form 29 structures 1 1 on the surface 9 of the filter element 1, which have interruptions to each other. The resulting circular disk-shaped structures are preferably able to generate different pressure differences over the entire circumference of a filter element 1 when flowing through the filter element with fluid 13.

It is understood that the embodiments of the matrix 33 shown in all figures can not only be formed as recesses 45, but also partially or entirely in the form of protrusions projecting from the surface 43 of the inner side 41 of each mold half 35.

During the Herste II process of a filter element 1 in the manner shown, filter aids with a chemical and / or physical action mechanism can also be introduced into the various filter layers 25, 25a, 25b.

Claims

P a n t a n s p r e c h e

Filter element with at least one mat or layer-shaped filter web (3) which forms at least partially with its outer side (5) a circumferentially closed filter jacket (7), wherein along the outside (5) of the filter jacket (7) takes place such a surface design or modification in that structures (1 1) of predeterminable contour and / or density connected to the filter jacket (7) are delimited from the other surface (9) of the filter web (3), characterized in that the structures (11) are applied by means of spray fiber application and Forming are generated such that in time first the structures (1 1) and subsequently the filter casing (7) or in reverse temporal order first the filter casing (7) and then the structures (1 1) or that at the same time both the filter casing (7 ) as well as the structures (1 1) in negative or positive form on the filter casing (7) arise.

Filter element according to claim 1, characterized in that the structures (1 1) as depressions design depressions in the filter casing (7) or as positive design elevations on the filter casing (7).

Filter element according to claim 1 or 2, characterized in that the structures (1 1) are an integral part of the filter jacket (7).

Filter element according to one of the preceding claims, characterized in that at least one structure (1 1) passes from a recess into an elevation and vice versa and / or that both at least one recess and an elevation spatially separated from each other in the respective filter casing (7) are present , Filter element according to one of the preceding claims, characterized in that the structures (1 1) predeterminable contour and / or density at least partially determine or influence the flow and / or the flow of fluid (13) of the filter jacket (7).

Filter element according to one of the preceding claims, characterized in that the structures (1 1) predeterminable contour and / or density effect the stiffening of the filter jacket (7) in the axial and / or radial direction at least partially.

Filter element according to one of the preceding claims, characterized in that the structures (1 1) predeterminable contour and / or density are at least partially formed by image (15) -, in particular by numeric or alphanumeric elements.

Filter element according to one of the preceding claims, characterized in that the structures (1 1) predeterminable contour and / or density have a line or strip-like shape.

9. Filter element according to one of the preceding claims, characterized in that the line or strip-like structures (1 1) extend substantially tangentially or substantially axially to the filter casing (7).

10. Filter element according to one of the preceding claims, characterized in that the line or strip-like structures (1 1) radially and / or tangentially and / or axially directed interruptions (1 7) or changes in direction (19).

1 1. Filter element according to one of the preceding claims, characterized in that the line or strip-like structures (1 1) occupy a defined distance (a) to each other.

12. Filter element according to one of the preceding claims, characterized in that the line or strip-like structures (1 1) intersect at least partially.

13. Filter element according to one of the preceding claims, characterized in that the line or strip-like structures (1 1) are S-shaped curved or serrated. 14. Filter element according to one of the preceding claims, characterized in that the structures (1 1) disc or circular elevations or depressions (21) on the surface (9) of the filter jacket (7). 15. Filter element according to one of the preceding claims, characterized in that the structures (1 1) on the Anström (22) - or outflow side (22 ') of the filter element (1) are arranged.

16. Filter element according to one of the preceding claims, characterized in that the structures (1 1) integral or attached

Part of the filter web (3) are.

1 7. Filter element according to one of the preceding claims, characterized in that the structures (1 1), as far as they are on the surface or top of the filter web (3) are placed from individual fibers

(23) consist of which also preferably the filter web (3) is constructed.

18. Filter element according to one of the preceding claims, characterized in that in addition to the filter web (3) further filter layers

(25a, 25b), preferably also with the inclusion of support grids are present, which result in a multilayer filter element structure.

19. Filter element according to one of the preceding claims, characterized in that the filter web (3) together with any further filter layers (25a, 25b) and support grids are guided in the manner of a cylindrical hollow element around a support tube around and that the above-mentioned components themselves extend between two end caps such that a tradeable assembly is provided.

20. Forming device for producing the filter element according to claim 1, characterized in that a mold (29) is present, whose mold surface (31) defines the demarcated structures (1 1) for the filter casing (7) of the filter element (1) in the Type of positive and / or negative matrix (33). ,

21. Shaping device according to claim 17, characterized in that the mold (29) is formed from at least two equally sized mold halves (35) which, when joined, at least partially define the delimited structures (11) of the filter web (3).

22. Molding device according to one of the preceding claims,

characterized in that the mold (29) is tubular and on its inner side (41) the respective matrix (33) for creating the demarcated structures (1 1) predeterminable contour and / or density for the filter web (3) is formed. 23. Molding device according to one of the preceding claims,

characterized in that in a free space (37) of the mold (29) at least the surface (9) of the filter web (3) forming nozzle means (39) is inserted, by means of the plastic melt (47) formed individual fibers (23) on the Inner side (41) of the mold (29) can be applied.

24. Molding device according to one of the preceding claims,

characterized in that the nozzle means (39) to mi least one, the free space (37) of the mold (29) axially extending nozzle lancet or a nozzle bar (40) is arranged

Method for producing delimited structures (1 1) of predeterminable contour and / or density relative to the filter casing (7) of the filter element (1) using a molding device (27), in each case according to one of the preceding claims, characterized in that at least the Surface (9) of the filter web (3) forming material is formed by the spray application of fibers (23) on a mold surface (31) of a mold (29) that the fibers (23) from a solid base material, which in a melt (47 ), are formed.

A method according to claim 22, characterized in that the at least the surface (9) of the filter web (3) forming material by a nozzle means (39) on the inside (41) of the mold (29) is sprayed.

Method according to one of the preceding claims, characterized in that the application of fibers (23) with respect to the mold (29) takes place continuously in the axial and / or radial direction by the nozzle device (39).

Method according to one of the preceding claims, characterized in that a predefinable layer thickness (S) of the material forming the surface (9) of the filter web (3) is produced by the continuous application of fibers (23) to the mold surface (31).

Method according to one of the preceding claims, characterized in that the fibers (23) in a layer thickness (S) of about 2 mm to 6 mm are applied to the mold surface (31). Method according to one of the preceding claims, characterized in that the surface (9) and / or the structures (1 1) of the filter web (3) forming material is selected such that a lower or higher filtration fineness than the filter web (3) itself is reached.