DE102017004946A1 - Filter element, filter, filter system and use of the filter - Google Patents

Abstract

A filter element for filtering intake air in a vehicle, the filter element having a frame, and wherein the filter element comprises at least two filter media disposed side by side in the frame, the filter material of the first filter medium being different from the filter material of the second filter medium; and a filter, a use of the filter and a filtration system.

Description

Technical area

The present application relates to a filter element, a filter with this filter element, a filter system and a use of the filter.

There are known filter elements which each serve a functionality, for example as a particle filter or for the removal of hydrocarbons. These are installed as separate elements in different areas of a vehicle.

An integration of a plurality of filter media in a flow direction within a housing leads to an increase in the installation space of the filter element and makes its arrangement in the limited space of a vehicle more difficult.

State of the art

Typically, a filter body consisting of a filter medium is held in a rack. Such a frame may for example be a box or a frame which encloses the filter body. It is also possible that the frame is formed of a cylindrical grid-shaped support tube and two end plates. The filter body is pushed over the support tube. The end plates form a stop during axial displacement of the filter body on the support tube.

Typically, a filter body is glued or welded to the edge of the frame. While the welding may mean weakening of the filter material in the edge region, it may occur in certain media, such as oils or fuels, weakening of the adhesive bond by dissolving a bonding agent used for bonding in the respective medium to be filtered.

Disclosure of the invention

Based on the aforementioned preliminary consideration, it is the object of the present invention to provide a filter element and a method for its production, with an optimal connection between the filter element and the molded body of the frame, for example an end plate. This optimal connection particularly preferably also has a high degree of impermeability to oils and fuels.

The present invention achieves this object by providing a filter element having the features of claim 1.

A filter element according to the invention comprises a filter body made of a filter medium and a shaped body of a frame enclosing the filter body at least partially.

The frame is part of the filter element. It may for example be cylindrical or box-shaped. The frame can also consist only of the molded body. However, it is also a multi-part structure of the frame, for example, with a cylindrical grid-shaped support body and two terminal arranged on the support body end plates possible.

The filter body is materially connected in a connection region with the molded body. Material fit or cohesive means that no pure mechanical form fit z. B. is done by jamming the filter material to the end plate, but the formation of a chemical bond between the filter body and the molding. Such a material connection is often achieved by gluing or fusing the two components to be joined. The first variant is typically carried out with the aid of a bonding agent or adhesive.

In the present case, however, the connection is formed by a material of the molded body and / or of the filter body that has been loosened in the connection area.

Since the connection of the two components takes place in partially or exclusively by annealed material of one of the two or both components, the connection of the two components can preferably take place without adhesion promoter.

Thus, common media to be filtered, such as oil and / or fuel, are filtered through the filter element without causing the bonding area of the two components to dissolve.

Advantageous embodiments of a filter element are the subject of the dependent claims.

The filter element may advantageously be a monolithic component of the shaped body and the filter body. Monolithic in this context means that the shaped body and the filter body are combined in one component. Regardless, the molded body may nevertheless consist of a solid material, in particular of plastic, and the filter body of a fiber material. However, it can no longer be made clear at which point the material transfer takes place, but the materials flow into each other fluently.

It has proved to be advantageous if the molded body consists of polyamide or at least partially coated with polyamide. This material is particularly suitable for dissolving and for subsequent connection with the filter material of the filter body when adding a carboxylic acid, in particular formic acid.

The connection region can preferably be formed without welding beads and / or free of melting zones. Typically, when the filter material is welded to the shaped body, a material overhang, a so-called welding bead, remains. This is not the case when solving the material of one or both connection partners and then connecting the connection partners. Also combustion residues of the plastic material, as they can occur as a result of melting in the region of a molten zone, can not be perceived in the connection area.

Both the shaped body and the filter body can have the same plastic material, preferably a polyamide, outside the connection area. Since, as is known, the same dissolves well in the same way and bonds to one another, it is particularly advantageous if both the shaped body and the filter material of the filter body have the same plastic material, at least to a certain extent. Thus, when both components are brought into contact in the presence of a carboxylic acid, both the filter and the shaped body dissolve somewhat.

The filter material of the filter body may preferably comprise a polyamide support grid and / or a support fiber layer, preferably a spunbond layer, of polyamide, which forms a bond with the molding. For this purpose, it is advantageous if the support fiber layer or the grid rest directly on the molding. The filter material can also have a filter fiber layer, which is arranged on the support fiber layer or the support grid and does not rest directly on the surface of the molding.

The polyamide support grid and / or the polyamide support fiber layer can advantageously be partially dissolved in the connection region, such that the fiber and / or the grid filament structure are arranged visible in the connection region on the molding and bonded to the molding. Thus, it is possible that the filaments and fibers are partially flowed on the surface, but still their position on the surface of the molding can be seen. These filaments or fibers allow a higher tensile strength between the filter medium and the molded body in the connection area.

The material of the shaped body and / or filter body can be dissolvable by a carboxylic acid-containing solvent, in particular by an acid containing formic acid. In particular, the connection between the shaped body and the filter body by a carboxylic acid-containing solvent, in particular by a formic acid-containing solvent, be on or dissolvable. In the present invention is between a medium to be filtered, z. As oil or fuel, and a distinction between a carboxylic acid-containing solvent. Apart from the abovementioned solvent, the material of the filter element in the connection region is chemically very resistant to a large number of media to be filtered. However, the solubility of the material by said solvent offers a possibility of working up and / or reuse, for example, of the molding.

The shaped body can advantageously be designed as a first of two end disks enclosing the filter body, as a box enclosing the filter body or as a frame enclosing the filter body.

• I Bereitstellen eines Filterkörpers aus einem Filtermedium und einen Formkörper eines den Filterkörper zumindest teilweise einfassenden Gestells, wobei der Filterkörper und/oder der Formkörper zumindest bereichsweise ein Material aufweist, welches in einem Lösungsmittel anlösbar ist;
• II Auftrag des Lösungsmittels auf die Oberfläche des Formkörpers und/oder Filterkörpers;
• III Inverbindungbringen des Filtermediums des Filterkörpers mit dem Formkörper des Gestells, wobei im Verbindungsbereich zwischen dem Filterkörper und Formkörper ein angelöstes Material des Filterkörpers und/oder Formkörpers angeordnet ist; und
• IV Aushärten des angelösten Materials zu einer fest verklebten und einer abdichtenden Verbindung zwischen dem Filterkörper und dem Formkörper.

A method according to the invention for producing a filter element, preferably a filter element according to the invention, comprises the following steps:

• I Providing a filter body of a filter medium and a shaped body of the filter body at least partially enclosing frame, wherein the filter body and / or the molding at least partially comprises a material which is dissolvable in a solvent;
• II application of the solvent on the surface of the molding and / or filter body;
• III bringing into connection of the filter medium of the filter body with the molded body of the frame, wherein in the connection region between the filter body and the molded body a dissolved material of the filter body and / or molded body is arranged; and
• IV hardening of the solute material to a firmly bonded and a sealing connection between the filter body and the molding.

Advantageous embodiments of the method are the subject of the dependent claims.

The solvent may advantageously have a content of at least 15% by weight, preferably at least 20% by weight, of concentrated carboxylic acid, preferably of formic acid. A dilute formic acid has a particularly short reaction time until the material is dissolved, especially polyamide, and is therefore optimal for use in the present process.

In addition, the dissolution in particular of a polyamide-containing molded body and / or filter body can be assisted if the solvent, in particular the carboxylic acid-containing solvent, at least 10 wt .-%, preferably at least 20 wt .-% of a dissolved or dissolved to the material of the shaped body and / or filter body plastic of the same kind, in particular a polyamide having. By adding a similar plastic to the solvent, the dissolution of the material of the filter and / or molded body is additionally supported. Identical means that it is dissolved or dissolved in the solvent plastic at least the same class of polymer, z. To the class of polyesters, polyamides, polyethylenes, polypropylenes and the like.

The contact time of the solvent on the molding and / or filter body is advantageously more than 30 seconds, preferably more than two minutes. As a result, the handling of the respective component is easier, and the solvent can be removed from unintentional job sites, without causing major damage to the material.

It is advantageous if the bringing into contact of the shaped body with the filter body takes place less than two hours after the application of the solvent to the shaped body and / or the filter body, which on the one hand requires little time for production, on the other hand hardening of the loosened plastic prevented before its connection with the material of the connection partner.

For a time-efficient procedure and a higher strength of the compound can advantageously be carried out curing under heat treatment.

Brief description of the drawings

In the drawings, an embodiment of a filter element according to the invention is shown. This will be described in more detail below, wherein also further embodiments of the invention are also explained. Show it:

1 a schematic perspective view of individual components of a filter element according to the invention in the disassembled state;

2 a schematic perspective view of a merging of the components of the filter element of 1 ;

3 a schematic perspective view of a progressive merging of the components of the filter element of 2 ; and

4 a schematic perspective view of the components of 1 - 3 in the progressive assembly to a filter element according to the invention.

Embodiment (s) of the invention

1 shows components of a filter element according to the invention 1 with a to a cylindrical filter body 2 trained bellows. The filter body 2 is formed of a filter medium. In this case, the filter body has a sequence of zigzag-shaped folds.

Another component of the filter element 1 of the 1 is supporting body 5 , This support body 5 is formed as a tubular grid with a longitudinal axis. In this case, the grid has annular grid transverse struts perpendicular to the longitudinal axis of the support body 5 on. The support body also has lattice longitudinal struts which are parallel to the longitudinal axis of the support body 5 run and connect the grid cross struts together on.

The supporting body 5 is preferably partially or completely formed of plastic. It serves the dimensional stability of the filter body 2 and is inside the filter body 2 arranged.

The supporting body 5 is in the filter element 1 inside the filter body 2 and coaxial with the filter body 2 arranged.

The filter body 2 is axial between two end discs 3 and 4 in the filter element 1 arranged. These end discs 3 and 4 are also partially or completely formed from a plastic. The end plates are plate-like and may be formed, for example, round or rectangular.

The filter element 1 can be arranged in a filter housing of a filter. The filter element 1 may preferably be a replaceable component of the aforementioned filter.

The variant of the 1 - 4 is only a variant of a filter element. For example, in the context of the present invention, it is also possible that a folded or unfolded filter body is enclosed in a frame or arranged in a box, which frame or box consists of a plastic. Such filters can, for. B. be formed as flat filter elements, in particular with a square frame surface.

The whole of the end discs 3 . 4 and supporting body 5 is referred to in the context of the present invention as a frame. This frame serves to support and surround the respective filter body 2 , This definition also includes the aforementioned framework or box. The frame is either a shaped body, z. As a box or frame or individual components of the frame are molded body, such. B. the end plates 3 and 4 and the support body 5 in 1 - 4 , At least one shaped body of the filter element has, together with the filter body 2 a connection area 6 on which in 4 by the end plate 3 is indicated.

The plastic from which the frame is partially or completely formed, may preferably be partially or completely formed as a thermoplastic, more preferably made of polyamide.

The filter body 2 is partially connected to the frame partially, in particular edge-side, material fit. Specifically, this relates to the facing surfaces of the two end plates 3 . 4 , which in a contact area with the filter medium of the filter body 2 are materially connected. Apart from the material of the filter medium and the frame or the end plates 3 . 4 does not become another adhesive for connecting the filter body 2 used with the frame.

The filter medium of the filter body 2 may also comprise a plastic and preferably be formed of a nonwoven comprising plastic fibers.

The plastic of the frame and / or filter medium can be adhesively bonded by dissolving.

The solvent used to dissolve the plastic is a carboxylic acid. The carboxylic acid may be a formic acid in a particularly preferred embodiment variant of the invention.

Also, individual components of the frame, in particular the support body 5 , can with at least one, preferably with both end discs 3 . 4 material fit by dissolving the plastic of the support body 5 and / or the end discs 3 . 4 be connected in the connection region of these two components.

The material connection between the filter body 2 and the frame takes place without melting, ie without occurrence of a melting zone with thermal degradation products of the respective plastic.

Also, a welding bead between the filter medium and the frame, which typically occurs during thermal welding of the filter medium to the frame, may be present in the connecting region 6 the filter body with the frame in the filter element according to the invention preferably can not be determined. The filter element is thus in the connection area 6 schweißwulstfrei.

In addition, the connection area points 6 no thermal discoloration, eg. B. black dyeings of the filter medium, on. However, depending on the type of plastic used, it can sometimes lead to a milky white discoloration of the surface.

Preferably, the filter medium comprises the filter body 2 and the frame at least in the connection area 6 both elements in each case a polyamide, in particular a polyamide of the same type.

Alternatively, instead of a plastic-containing medium, it is also possible to use a medium which comprises cellulose fibers and / or consists of cellulose fibers.

Thus, between the filter body 2 and the frame generates a polyamide / polyamide compound by dissolving the surface of at least one of the two components. In particular, lies in the connection area 6 both elements a compound of a single plastic, the corresponding polyamide, before.

Straight polyamide has a particularly good chemical and / or mechanical resistance for a filter element. This is especially true for high fuel and oil resistance. Therefore, a preferred use of the filter element according to the invention 1 in an oil filter, oil separator, fuel filter or fuel separator, in particular before the supply of the respective fluids in an internal combustion engine.

It thus creates a monolithic component of frame and filter body. The bonding between the filter body 2 and the frame is preferably in all three dimensions, since the filter medium may partially sink into the surface by the dissolution of the surface, in particular the surface of the frame, so that individual fibers of the filter medium preferably not only superficially, but partially to more than 35% the fiber circumference, preferably more than 50% of the fiber circumference, are wetted with the material of the frame.

Due to the novel compound and the method for its production and filter elements with complex structures and complex components can be integrated in a filter element. So far this was only possible to a limited extent since, due to their dimensioning, welding tools for fusing or bonding individual components could not be optimally brought to a connection region to be created.

To create an optimal connection, the frame, in 1 - 4 the end discs 3 . 4 have a surface of polyamide at least in the connection region with the filter body. At the same time, the filter body 2 at least in the connection area 6 with the frame, a proportion of at least 10 wt .-%, preferably of at least 50 wt .-%, of polyamide.

The filter medium of the filter body 2 may preferably comprise at least about 50% by weight of one or more polyamides and / or one or more polyesters.

The filter element of the filter body can in particular be needled. In an advantageous embodiment, the filter medium may be a fiber-containing medium layer, in particular as a nonwoven fabric. Particularly preferably, the medium layer can additionally be supported by a grid and / or a spunbond layer. The grid and / or Spunbondlage may preferably comprise a thermoplastic material, particularly preferably a polyamide, or consist of such a material. This is particularly preferred since the fiber or lattice structure of the spunbond layer or the lattice layer is partly dissolved even after the connection with the molded body and at the same time is also partially retained, and thus a higher tensile strength of the filter medium in the connection region 6 can be achieved. The lattice and / or the Spunbondlage is in the connection of the filter medium with the molding to the molding, for example, to the end plate 3 . 4 directed towards.

In this embodiment, the fibrous medium layer may preferably consist of polyamide fibers, polyester fibers, cellulose fibers or the like.

The method for producing a filter element according to the invention will be discussed in more detail below.

In a first method step I, the provision of the shaped body, in particular of plastic, of the frame takes place. This shaped body can, for example, one or more of the end plates 3 . 4 of the 1 - 4 or a box in which the filter body 2 can be arranged.

Then, in a process step II, an application of a solvent takes place on the surface of the shaped body. The order is preferably carried out in areas. The solvent is preferably carboxylic acid-containing. The carboxylic acid content of the solvent may preferably be at least 15% by weight, more preferably at least 20% by weight. It can thus be used as a dilute carboxylic acid in the present process as a solvent. The dilution of the carboxylic acid may, for. Example, with an alcohol, with water, with acetone or the like.

The carboxylic acid used may preferably be formic acid, more preferably containing between 15-60% by weight. Preferred means of dilution is water.

The solvent takes some time to act. The exposure time is preferably at least 30 seconds, more preferably at least two minutes.

Subsequently, in step III, a connection of the filter medium of the filter body takes place 2 with the loosened molded body of the frame. As part of bringing in connection, pressing of the filter medium onto the shaped body can take place. The material of the filter medium is wetted with the loosened material of the molding and can preferably also be dissolved.

The process step III can preferably be carried out less than two hours after the dissolution in order to prevent premature curing of the dissolved material.

Finally, in method step IV, the material is cured to form a firmly bonded connection. The curing may by drying apparatus, eg. As a hot air dryer or a drying oven can be supported. The formic acid and any other solvent can evaporate better.

1 - 4 shows a filter body of a folded filter medium. However, a filter body used in a filter element according to the invention may alternatively and preferably also be formed from a wound filter medium.

In method step II, it is also possible to apply a solvent, in particular a carboxylic acid-containing solvent, to the molding, in which plastic particles, eg. As polyamide particles, dissolved or at least be present dissolved. The plastic fraction in the solvent may preferably be more than 20% by weight, preferably between 22 and 65% by weight.

In the context of the present invention, a leak test was carried out with respect to the in 1 - 4 illustrated embodiment for checking the tightness of the joint between the end plates 3 . 4 and the filter body 2 carried out.

First, a filter element according to the invention was produced. For this purpose, a first and a second filter element with end disks made of polyamide and a first filter body made of cellulose fibers and a second filter body made of polyester with polyamide support grid was used.

The first filter element with the cellulosic fiber filter body has a weight of 1.5 kg, and the second filter medium with the polyester-polyamide lattice filter body has a weight of 2.0 kg.

To one of the end discs 3 . 4 a hose ring was stretched. Subsequently, 2 ml of the first filter medium or 4 ml of formic acid for the second filter medium were added to each end plate.

Subsequently, the filter body was peripherally connected to the end plates.

The filter elements were weighted and placed in a drying oven at preferably at least 60 ° C, especially at 80 ° C.

The exposure time before the drying oven was 3 minutes. The drying time in the drying oven was preferably more than 5 minutes, in particular 7 minutes.

This was followed by a leak test with gasoline as the test medium at different pressures of the test medium. In the leak test, also called bubble test, was carried out at an overpressure of 9 mbar, 10 mbar, 11 mbar, 15 mbar, 20 mbar and 25 mbar no medium through the junction.

At 20 mbar and 25 mbar, small bubbles the size of champagne bubbles rose from the medium.

This leak test or the bladder test according to ISO 2942-5.2 was done with the filter elements. Overall, the bubble test was passed through the filter element according to the invention.

By the aforementioned manufacturing method, a uniform folding pitch of a folded filter body can also be achieved.

The end plates of the embodiment of the 1 - 4 are arranged parallel to each other. The manufacture of the filter element according to the invention by the method according to the invention can be carried out with great accuracy and / or dimensional accuracy.

Although the present invention has been described in detail with reference to preferred embodiments, it is not limited thereto, but variously modifiable.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• ISO 2942-5.2 [0081]

Claims (17)

Filter element ( 1 ) comprising a filter body ( 2 ) of a filter medium and a shaped body of the filter body ( 2 ) at least partially enclosing frame, wherein the filter body ( 2 ) in a connection area ( 6 ) is materially connected to the molded body, characterized in that the connection by a in the connection area ( 6 ) annealed material of the shaped body and / or of the filter body ( 2 ) is formed. Filter element according to claim 1, characterized in that the filter element ( 1 ) a monolithic component of the shaped body and the filter body ( 2 ). Filter element according to claim 1 or 2, characterized in that the molded body consists of polyamide or at least partially coated with polyamide. Filter element according to one of the preceding claims, characterized in that the connection region ( 6 ) is designed without welding beads and / or free from melting zones. Filter element according to one of the preceding claims, characterized in that both the shaped body and the filter body ( 2 ) outside the connection area ( 6 ) has the same plastic material, preferably polyamide. Filter element according to one of the preceding claims, characterized in that the filter material of the filter body ( 2 ) has a polyamide support grid and / or a support fiber layer, preferably a spunbond layer of polyamide. Filter element according to claim 6, characterized in that the polyamide support grid and / or the polyamide support fiber layer partially dissolved in the connection area ( 6 ) is present, such that the fiber and / or grid filament structure visible in the connection area are arranged on the molded body and bonded to the molded body. Filter element according to one of the preceding claims, characterized in that the material of the shaped body and / or the filter body ( 2 ) are dissolvable by a carboxylic acid-containing solvent, in particular by a solvent containing formic acid. Filter element according to one of the preceding claims, characterized in that the shaped body as a first of two the filter body ( 2 ) enclosing end discs ( 3 . 4 ), as the filter body ( 2 ) enclosing box or as the filter body ( 2 ) enclosing frame is formed. Filter element according to one of the preceding claims, characterized in that the connection between the shaped body and the filter body ( 2 ) by a carboxylic acid-containing solvent, in particular by a formic acid-containing solvent, is soluble or dissolvable. Method for producing a filter element, preferably a filter element ( 1 ) according to one of the preceding claims, characterized by the following steps: I providing a filter body ( 2 ) of a filter medium and a shaped body of the filter body ( 2 ) at least partially enclosing frame, wherein the filter body ( 2 ) and / or the molding at least partially comprises a material which is dissolvable in a solvent; II application of the solvent to the surface of the shaped body and / or the filter body ( 2 ); III bringing the filter medium of the filter body ( 2 ) with the molded body of the frame, wherein in the connection region between the filter body ( 2 ) and the shaped body a loosened material of the filter body ( 2 ) and / or the shaped body is arranged; and IV curing of the dissolved material to a firmly bonded and a sealing connection between the filter body ( 2 ) and the molding. A method according to claim 11, characterized in that the solvent has a content of at least 15 wt .-%, preferably at least 20 wt .-%, of concentrated carboxylic acid, preferably of formic acid. Method according to one of the preceding claims, characterized in that the solvent at least 10 wt .-%, preferably at least 20 wt .-% of a dissolved or dissolved to the material of the shaped body and / or the filter body of the same type plastic, in particular a polyamide having. Method according to one of the preceding claims, characterized in that the contact time of the solvent on the shaped body and / or filter body ( 2 ) is more than 30 seconds, preferably more than two minutes. Method according to one of the preceding claims, characterized in that the bringing in connection takes place less than two hours after the application of the solvent ( 2 ) on the shaped body and / or the filter body ( 2 ) he follows. Method according to one of the preceding claims, characterized in that the curing takes place under heat treatment. Use of the filter element according to one of the preceding claims in an oil filter, an oil separator, fuel filter or a fuel separator, in particular before being fed into an internal combustion engine.

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