Filter insert for a filter unit

Abstract

The invention relates to a filter insert (10) for a filter unit which comprises an electric supply module, comprising an electrically insulating filter material (14), at least one electrically conductive polarization element (16a, 16b) to which an electric voltage can be applied in order to polarize the filter material (14), and an elongate electric line path (20) for energizing the polarization element (16a, 16b), said line path running along a contacting surface (22) of the filter insert (10).

Description

[0001] Filter insert for a filter unit

[0002] The invention relates to a filter insert for a filter unit comprising an electrical supply module, with an electrically insulating filter material and at least one electrically conductive polarization element to which an electrical voltage can be applied to polarize the filter material.

[0003] Furthermore, the invention relates to a filter unit with a replaceable filter insert and an electrical supply module for supplying power to the filter insert.

[0004] Furthermore, the invention relates to a method for producing a filter insert comprising the step of providing an electrically insulating filter material and at least one electrically conductive polarizing element to which an electrical voltage can be applied in order to polarize the filter material.

[0005] Filters that operate with electrical polarization typically require a conductor arrangement for electrical contact, allowing the filter to be powered by an electrical supply module. The electrical paths of the conductor arrangement are currently implemented using stranded wires or conductive plastics.

[0006] However, such conductor arrangements are associated with comparatively high manufacturing and material costs. The object of the invention is therefore to reduce the manufacturing costs of a filter related to the electrical contacting.

[0007] The object is achieved by a filter insert of the type mentioned at the outset, wherein the filter insert according to the invention has an elongated electrical conduction path for energizing the polarization element, which runs along a contact surface of the filter insert.

[0008] The filter insert can be contacted by bringing the electrical conduction path into contact with one or two contact poles of the electrical supply module. For this purpose, the electrical supply module can comprise spring contacts, contact pins, hook strips, or other electrically conductive contact elements. The electrically conductive conduction path can have a path width in a range between 0.5 and 20 mm, preferably in a range between 1 and 5 mm. The polarizing element can be an electrically conductive nonwoven layer.

[0009] In a preferred embodiment of the filter insert according to the invention, the polarizing element is designed as a polarizing layer. The polarizing layer preferably runs parallel to the electrically insulating filter material and / or is in planar contact with the electrically insulating filter material.

[0010] Furthermore, a filter insert according to the invention is preferred in which two electrically conductive polarizing elements, each formed as a polarizing layer, are separated from each other by the electrically insulating filter material. An electrical voltage can be applied to the polarizing layers to polarize the filter material. The electrically insulating filter material and the two electrically conductive polarizing layers preferably form a pleated layer composite.

[0011] In a preferred embodiment of the filter insert according to the invention, the contact surface is an outer surface of the filter insert. Alternatively or additionally, the contact surface is located on an elongated material strip of the filter insert. The filter insert preferably has two opposite long lateral sides and two opposite short lateral sides. The contact surface is preferably located on a long lateral side or on a short lateral side of the filter insert. The elongated material strip can be a side lamination of the filter insert.

[0012] In a further embodiment of the filter insert according to the invention, the contact surface is located on a side lamination of the filter insert. The at least one electrical conduction path extends over at least half, in particular over at least 70%, of the length of the side lamination of the filter insert. The at least one electrical conduction path can also extend over the entire length of the side lamination of the filter insert.

[0013] In an advantageous development of the filter insert according to the invention, the electrical conduction path extending along the contact surface runs partially or completely in a straight line. In this case, the electrical conduction path is preferably a straight, electrically conductive strip. The electrical conduction path can extend along a large part of the contact surface or along the entire contact surface and / or run in a straight line over the entire extension area. Furthermore, the electrical conduction path extending along the contact surface can run partially or completely in a zigzag pattern, in serpentine lines, or in another regular pattern. With the regular pattern, the electrical resistance preferably increases proportionally to the length of the electrical conduction path.

[0014] The filter insert according to the invention is further advantageously developed in that the electrical conduction path running along the contacting surface extends at least over half, preferably over at least 70%, of the length of the contacting surface, in particular over the entire length of the contacting surface. Alternatively or additionally, the electrical conduction path running along the contacting surface extends at least over half, preferably over at least 70%, of the length of the filter insert, in particular over the entire length of the filter insert. Alternatively or additionally, the electrical conduction path running along the contacting surface extends at least over half, preferably over at least 70%, of the width of the filter insert, in particular over the entire width of the filter insert.The electrical conduction path running along the contacting surface preferably extends at least over half, in particular over at least 70%, of the length of the side lamination of the filter insert, in particular over the entire length of the side lamination of the filter insert.

[0015] The filter insert according to the invention is further advantageously developed in that the electrical conduction path is formed by an electrically conductive material, wherein the electrically conductive material is located directly on the contact surface. In this case, there are no intermediate layers between the contact surface and the electrical conduction path, in particular no carrier layer that supports the electrical conduction path. The electrical conduction path is preferably formed from a cured adhesive material, so that no separate adhesive layer, for example, made of adhesive, is required between the contact surface and the electrically conductive material.

[0016] In another preferred embodiment of the filter insert according to the invention, the electrical conduction path is formed as a printed conductor track and / or printed onto the contact surface. Preferably, the printing paste or printing paste mixture is applied directly to the contact surface, in particular the side lamination. The contact surface can be processed before the electrical conduction path is printed, for example, by surface treatment. This processing can prepare the contact surface for printing.

[0017] In a further preferred embodiment of the filter insert according to the invention, the contact surface in the region of the electrical conduction path is surface-treated, in particular thermally surface-treated and / or smoothed. For example, the side lamination can be prepared over the entire surface or locally with a heated flat iron as part of print preparation in order to create a flat and smooth printing surface for printing the electrical conduction path. In another embodiment of the filter insert according to the invention, the electrical conduction path is part of a voltage divider. The electrical conduction path can function in sections as a resistance path of the voltage divider. By using the voltage divider, the supply voltage of the filter insert can be reduced to a voltage level suitable for polarization by means of a suitable voltage tap along the resistance path.Due to the voltage reduction, the voltage divider allows a significantly higher ionization voltage to be used for contacting, which can then be applied, for example, to an ionizer in the filter unit. If the filter unit includes an ionizer, no additional high-voltage source is required. The ionizer's high-voltage source can be used for polarization via a voltage tap. This also eliminates the need for additional wiring. For example, the voltage can be tapped directly from the ionizer, provided it is conveniently located near the filter insert or is designed as part of the filter insert. By having the voltage divider directly on the filter insert, the appropriate polarization voltage can be specified by the filter insert via a suitable voltage divider. This improves the adaptability and compatibility of the filter insert.This allows the filter insert to be adapted to a different polarization voltage by selecting a suitable voltage divider. This different polarization voltage can then be individually specified, for example, using a filter variant, without the manufacturer of the air conditioning system or the vehicle having to provide a different supply voltage. This significantly reduces variant management. Furthermore, further development of the system can also take place within the product life cycle. Further development of the system may necessitate a change in the required polarization voltage. This changed polarization voltage can be specified directly via an adapted voltage divider, without the need for a complex product modification to the high-voltage source. This significantly reduces change management.

[0018] The filter insert according to the invention is further advantageously developed in that the electrical conduction path has an electrical resistance of at least 10 kΩ. The electrical or ohmic resistance reduces the current flow through the voltage divider to a minimum, so that only very little energy is drawn. However, a minimum current must flow to achieve a voltage reduction along the resistance path and thus also to tap a reduced voltage for polarization. The resistance is also advantageous because it protects the filter insert from excessively high discharge energies in the event of electrical short circuits. These can permanently short-circuit the filter insert through local carbonization of the non-conductive filter material, meaning that no voltage can be applied. In this case, the filter material would then no longer be polarizable.Furthermore, the resistor makes it possible to test the filter element for the presence and / or correct contact of the filter element by applying a test voltage and comparing the resulting current flow with the expected current flow. Another advantage is that the resistor path discharges the live side to the ground side when the system is switched off, thus preventing a voltage potential when the system is switched off. This protects people from unwanted electrical arcing during filter replacement.

[0019] Furthermore, a filter insert according to the invention is preferred in which the electrical conduction path is part of a conductor carrier applied to the contacting surface. The conductor carrier can be designed as a carrier film or carrier label. The carrier label can be an adhesive label. The conductor carrier can be a plastic film or comprise a plastic film. The conductor carrier can be a polyethylene terephthalate film (PET film) or comprise a polypropylene terephthalate film. The conductor carrier can be a polypropylene film (PP film) or comprise a polypropylene film. Alternatively, the conductor carrier can also be a plate, in particular a plastic plate. The conductor carrier can also be a carrier material or a carrier textile. The conductor carrier can be, for example, a carrier fleece. The conductor carrier can be adhesively bonded to the contacting surface.The at least one electrical conduction path can be a printed electrically conductive track. The conductor carrier can have a carrier layer, wherein the at least one electrical conduction path can be printed onto the carrier layer.

[0020] In a particularly preferred embodiment of the filter insert according to the invention, the electrical conduction path running along the contact surface is electrically conductively connected to the polarization element by means of at least one contacting element. The electrical conduction path is preferably electrically conductively connected to a first polarization element via a first contacting element and electrically conductively connected to a second polarization element via a second contacting element.

[0021] In another preferred embodiment of the filter insert according to the invention, the contacting element is designed as an electrically conductive contacting strip or as an electrically conductive contacting band. Thus, the position of the contacting element is variable. The contacting strip or contacting band can be formed from an electrically conductive nonwoven. The contacting strip or contacting band can be an electrically conductive plastic element, in particular an injection-molded plastic element. The contacting strip or contacting band can form a contacting tab. The contacting strip or contacting band can be designed as a contacting film, in particular a self-adhesive one.

[0022] The filter insert according to the invention is further advantageously developed in that the contacting element is an integral component of the polarizing element. For example, the contacting element is a layer section separated from the polarizing element. The separated layer section is preferably folded out of the polarizing element plane. The separation can be carried out by cutting or punching. If the polarizing element has a lamination, this is preferably removed in the region of the separated layer section. After being folded out or by being folded out, the contacting element is then brought into contact with the elongated electrical conduction path running along the contacting surface. In another preferred embodiment, the filter insert according to the invention has a first and a second polarizing element and a first and a second contacting element.The electrical conduction path is electrically conductively connected to the first polarization element via the first contacting element and electrically conductively connected to the second polarization element via the second contacting element. Preferably, the first and second polarization elements are each formed as a polarization layer. The electrically insulating filter material and the first and second electrically conductive polarization layers preferably form a pleated layer composite. The first and second polarization layers are preferably electrically conductively connected to one another via the first contacting element, the second contacting element, and a section of the conduction path extending between the first and second contacting elements.

[0023] In another preferred embodiment of the filter insert according to the invention, an electrically conductive contact path is interrupted between the electrical conduction path running along the contact surface and the polarization element, in particular on the contact surface. The electrical conduction path running along the contact surface is therefore not electrically conductively connected to the polarization element when the filter insert is not in contact. The interruption of the contact path is preferably bridged during insertion of the filter insert by an electrically conductive connecting element in the receiving area for the filter insert or a contact pole of the electrical supply module, so that the polarization element is energized. The interruption of the contact path provides protection against incorrect installation and the use of unsuitable filter inserts.

[0024] In a particularly preferred embodiment of the filter insert according to the invention, the elongated electrical conduction path, which runs along the contact surface, is electrically conductively connected to two contact points located on the contact surface, which are wider than the electrical conduction path and serve to electrically conductively contact the filter insert with contact poles of the electrical supply module. The contact points are preferably located on the side lamination. A first contact point preferably has a first distance from a first end edge of the side lamination. A second contact point preferably has a second distance from a second end edge of the side lamination. The first distance and the second distance preferably correspond. The first contact point and the second contact point are preferably the same distance from a central axis of the filter insert.

[0025] In a further preferred embodiment of the filter insert according to the invention, the electrical conduction path for energizing the polarizing element is an integral component of the contact surface. Preferably, the electrical conduction path is an integral component of the side lamination of the filter insert. The electrical conduction path can be a nonwoven strip of the side lamination formed from electrically conductive fibers.

[0026] The object underlying the invention is further achieved by a filter unit of the type mentioned above, wherein the filter insert of the filter unit according to the invention is designed according to one of the embodiments described above. With regard to the advantages and modifications of the filter unit according to the invention, reference is therefore first made to the advantages and modifications of the filter insert according to the invention.

[0027] In a preferred embodiment, the filter unit according to the invention has an ionizer operated with high voltage, wherein the electrical supply module is configured to supply current to the ionizer. The electrical supply module therefore serves, on the one hand, to supply current to the polarization elements and, on the other hand, to supply current to the ionizer. If the ionizer is to be operated with a higher voltage than the polarization voltage, the voltage provided by the electrical supply module can be reduced via a voltage divider and a suitable voltage tap along the resistance path. A current source can be used to supply current to the ionizer. The voltage generated at the ionizer can then be used for polarization, in particular by reducing the voltage level using a voltage divider.The object underlying the invention is further achieved by a method of the type mentioned above, wherein, within the scope of the method according to the invention, an elongated electrical conduction path running along a contact surface of the filter insert is created for energizing the polarization element. The method is preferably used to produce a filter insert according to one of the embodiments described above. With regard to the advantages and modifications of the method according to the invention, reference is therefore first made to the advantages and modifications of the filter insert according to the invention.

[0028] In a preferred embodiment of the method according to the invention, the electrical conduction path is created by applying an electrically conductive material to the contacting surface. Alternatively or additionally, the electrical conduction path is created by printing an electrically conductive conductor track onto the contacting surface. The electrically conductive material or the electrically conductive conductor track is thus applied directly to the contacting surface, so that in this case, no intermediate layer is present between the electrically conductive material or the electrically conductive conductor track and the contacting surface.

[0029] The method according to the invention is further advantageously developed in that the contact surface is surface-treated, in particular thermally surface-treated and / or smoothed, before the electrical conduction path is created. Preferably, as part of the print preparation, the entire or localized preparation of the printing surface is carried out using a smoothing iron to create a flat and smooth printing surface for printing the electrical conduction path.

[0030] A method according to the invention is further advantageous in which the electrical conduction path running along the contacting surface is electrically conductively connected to the polarizing element by means of at least one contacting element. Preferably, the electrical conduction path is electrically conductively connected to a first polarizing element via a first contacting element and electrically conductively connected to a second polarizing element via a second contacting element. The contacting element can be an electrically conductive contacting strip or an electrically conductive contacting band.

[0031] Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings.

[0032] Fig. 1 shows a filter insert according to the invention in a perspective

[0033] Depiction;

[0034] Fig. 2 shows a further filter insert according to the invention in a perspective view;

[0035] Fig. 3 shows a further filter insert according to the invention in a perspective view;

[0036] Fig. 4 shows a further filter insert according to the invention in a perspective view;

[0037] Fig. 5 shows a conductor carrier of a filter insert according to the invention in a perspective view;

[0038] Fig. 6 shows a further conductor carrier of a filter insert according to the invention in a perspective view; and

[0039] Fig. 7 shows a method according to the invention in a flow chart.

[0040] Figure 1 shows a filter insert 10 for a filter unit that can be used in a motor vehicle. The filter unit serves, for example, as the interior air filter of the motor vehicle.

[0041] The filter insert 10 comprises a pleated multilayer composite 12. The composite 12 comprises an electrically insulating filter material 14 and two electrically conductive polarizing elements 16a, 16b. The polarizing elements 16a, 16b are designed as polarizing layers. An upper polarizing layer 16a is located above the filter material 14. A lower polarizing layer 16b is located below the filter material 14.

[0042] Material strips 18a, 18b run along the outer edges of the pleated layer composite 12. The material strips 18a, 18b form the side laminations of the filter insert 10 and are integrally bonded, for example, by adhesive bonding, to the pleated layer composite 12.

[0043] The filter insert 10 comprises at least one elongated electrical conduction path 20 for energizing the polarization elements 16a, 16b. The at least one conduction path 20 runs along at least one contact surface 22 of the filter insert 10. The contact surface 22 is at least one outer surface of the filter insert 10 and is located on the elongated material strip 18a and / or 18b.

[0044] The contact surface 22 can also extend over several outer surfaces of the filter insert, in particular several side laminations, for example over one side, two sides, three sides or four sides of the filter insert 10. Preferably, the contact surface 22 runs only on one side lamination or two opposite side laminations.

[0045] The contacting of the filter insert 10 is effected by bringing the electrical conduction path 20 into contact with two contact poles 100a, 100b of an electrical supply module of the filter unit.

[0046] The electrical conduction path 20 running along the contact surface 22 is completely straight and extends over the entire length of the contact surface 22. The electrical conduction path 20 is formed by an electrically conductive material, wherein the electrically conductive material is located directly on the contact surface 22. The electrical conduction path 20 is designed as a printed conductor track and is printed onto the contact surface 22.

[0047] Figure 2 shows that the electrical conduction path 20 running along the contact surface 22 is electrically conductively connected to the polarization elements 16a, 16b by means of contact elements 24a, 24b. The electrical supply path 20 is electrically conductively connected to a first polarization element via the contact element 24a and electrically conductively connected to a second polarization element 16b via the contact element 24b.

[0048] The contact elements 24a, 24b are designed as electrically conductive contact strips and are integral components of the polarizing elements 16a, 16b. The contact element 24a is a layer section separated from the polarizing element 16a and folded out of the polarizing element plane. The contact element 24b is a layer section separated from the polarizing element 16b and also folded out of the polarizing element plane. After folding out, the contact elements 24a, 24b are brought into contact with the elongated electrical conduction path 20, which runs along the contact surface 22.

[0049] The electrical conduction path 20, together with the contacting elements 24a, 24b, forms a voltage divider 26. Along the resistance path 28 of the voltage divider 26, the contacting element 24a taps a suitable voltage level for polarizing the filter material 14. Contacting of the filter insert 10 is achieved by bringing the electrical conduction path 20 into contact with two contact poles 100a, 100b of the electrical supply module.

[0050] In the filter insert 10 shown in Fig. 3, the electrical conduction path 20 is part of a conductor carrier 30 applied to the contact surface 22. The conductor carrier 30 is a carrier film designed as an adhesive film. The conductor carrier 30 is thus glued to the contact surface 22. The electrical conduction path 20 is a printed electrically conductive track. The conductor carrier 30 has a carrier layer, with the electrical conduction path 20 printed onto the carrier layer.

[0051] Fig. 4 shows that the polarizing elements 16a, 16b are connected to contacting elements 24a, 24b, wherein the contacting elements 24a, 24b are not electrically conductively connected to the conducting path 20 on the contacting surface 22. The interruptions between the conducting path 20 and the contacting elements 24a, 24b are bridged by connecting elements 102a, 102b of the electrical supply module upon insertion of the filter insert 10, thus enabling the application of a polarizing voltage to the polarizing elements 16a, 16b. Furthermore, upon insertion of the filter insert 10, contact poles 100a, 100b are brought into contact with the electrical conducting path 20. The contact pole 100b also functions as a connecting element 102b.

[0052] Fig. 5 shows that the electrical conduction path 20 can be part of a conductor carrier 30, which can be applied to the contact surface 22 of the filter insert 10. The conductor carrier 30 can be an elongated carrier film, which can be glued as an adhesive film to the side lamination of a filter insert 10.

[0053] Fig. 6 shows a conductor carrier 30 which is designed as a self-adhesive carrier label.

[0054] The electrical conduction path 20 of the conductor carrier 30 is connected to two contact points 32a, 32b, which are wider than the electrical conduction path 20 and serve for the electrically conductive contact of the filter insert 10 with contact poles 100a, 100b of an electrical supply module of the filter unit.

[0055] The conduction path 20, together with the contacting elements 24a, 24b and the contact points 32a, 32b, forms a voltage divider 26 with a resistance path 28.

[0056] Fig. 7 shows a method for producing a filter insert 10. In step 200, a pleated layer composite 12 with an electrically insulating filter material 14 and two electrically conductive polarization layers 16a, 16b is first provided, wherein the side edges of the pleated layer composite 12 are connected with a side lamination.

[0057] In step 202, an elongated electrical conduction path 20 is created, running along a contact surface 22 of the filter insert 10, for energizing the polarization elements 16a, 16b. The contact surface 22 is located on the side lamination of the filter insert 10. The creation of the electrical conduction path 20 includes step 204, which involves printing an electrically conductive trace onto the contact surface 22.

[0058] Subsequently, in step 206a, a first polarization element 16a is connected to the electrical conduction path by means of a contact element 24a formed as a contact strip. Furthermore, in step 206b, a second polarization element 16b is connected to the electrical conduction path 20 by means of a contact element 24b formed as a contact strip.

[0059] Reference symbol

[0060] 10 filter inserts

[0061] 12 layer composite

[0062] 14 Filter material

[0063] 16a, 16b Polarizing elements

[0064] 18a, 18b material strips

[0065] 20 Conductor path

[0066] 22 Contact surface

[0067] 24a, 24b Contact element

[0068] 26 voltage dividers

[0069] 28 resistance section

[0070] 30 cable carriers

[0071] 32a, 32b Contact points

[0072] 100a, 100b contact poles

[0073] 102a, 102b Fasteners

[0074] 200-204 Procedural steps

[0075] 206a, 206b Procedural steps

Claims

Claims 1. A filter insert (10) for a filter unit comprising an electrical supply module, comprising an electrically insulating filter material (14); and at least one electrically conductive polarizing element (16a, 16b) to which an electrical voltage can be applied to polarize the filter material (14); characterized by at least one elongated electrical conduction path (20) for energizing the polarizing element (16a, 16b), which extends along a contact surface (22) of the filter insert (10).

2. Filter insert (10) according to claim 1, characterized in that the polarizing element (16a, 16b) is designed as a polarizing layer.

3. Filter insert (10) according to claim 1 or 2, characterized by two electrically conductive polarizing elements (16a, 16b) each designed as polarizing layers, which are separated from one another by the electrically insulating filter material (14).

4. Filter insert (10) according to claim 3, characterized in that the polarization layers are electrically conductively connected to one another over a partial section of the conduction path (20).

5. Filter insert (10) according to one of the preceding claims, characterized in that the contacting surface (22) is at least one outer surface of the filter insert (10) and / or is located on at least one elongate material strip (18a) of the filter insert (10).

6. Filter insert (10) according to claim 5, characterized in that the contacting surface (22) is located on a side lamination of the filter insert (10), wherein the at least one electrical conduction path (20) extends at least over half, in particular over at least 70%, of the length of the side lamination of the filter insert (10), or over the entire length of the side lamination of the filter insert (10).

7. Filter insert (10) according to one of the preceding claims, characterized in that the at least one electrical conduction path (20) extending along the contact surface (22) runs in a straight line in sections or completely.

8. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) running along the contacting surface (22) extends at least over half, preferably over at least 70 percent, of the length of the contacting surface (22), in particular over the entire length of the contacting surface (22); and / or extends at least over half, preferably over at least 70 percent, of the length of the filter insert (10), in particular over the entire length of the filter insert (10); and / or extends at least over half, preferably over at least 70 percent, of the width of the filter insert (10), in particular over the entire width of the filter insert (10).

9. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) is formed by an electrically conductive material, wherein the electrically conductive material is located directly on the contact surface (22).

10. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) is designed as a printed conductor track and / or is printed onto the contacting surface (22).

11. Filter insert (10) according to one of the preceding claims, characterized in that the contact surface (22) in the region of the electrical conduction path (20) is surface-treated, in particular thermally surface-treated and / or smoothed.

12. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) is a component of a voltage divider (26).

13. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) has an electrical resistance of at least 10 kOhm.

14. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) is a component of a conductor carrier (30) applied to the contacting surface (22).

15. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) running along the contacting surface (22) is electrically conductively connected to the polarizing element (16a, 16b) by means of at least one contacting element (24a, 24b).

16. Filter insert (10) according to claim 15, characterized in that the contacting element (24a, 24b) is designed as an electrically conductive contacting strip or as an electrically conductive contacting band.

17. Filter insert (10) according to claim 16, characterized in that the contacting element (24a, 24b) is an integral part of the polarizing element (16a, 16b).

18. Filter insert (10) according to one of the preceding claims, characterized by a first and a second polarization element (16a, 16b); and a first and a second contacting element (24a, 24b); wherein the electrical conduction path (20) is electrically conductively connected to the first polarization element (16a) via the first contacting element (34a) and electrically conductively connected to the second polarization element (16b) via the second contacting element (34b).

19. Filter insert (10) according to one of the preceding claims, characterized in that an electrically conductive contact path between the electrical conduction path (20) running along the contact surface (22) and the polarizing element (16a, 16b), in particular on the contact surface (22), is interrupted.

20. Filter insert (10) according to one of the preceding claims, characterized in that the elongated electrical conduction path (20) which runs along the contact surface (22) is electrically conductively connected to two contact points (32a, 32b) located on the contact surface (22), which contact points are wider than the electrical conduction path (20) and serve for the electrically conductive contacting of the filter insert (10) with contact poles (100a, 100b) of the electrical supply module.

21. Filter insert (10) according to one of the preceding claims, characterized in that the electrical conduction path (20) for energizing the polarizing element (16a, 16b) is an integral part of the contacting surface (22).

22. A filter unit comprising a replaceable filter insert (10); and an electrical supply module for supplying power to the filter insert (10); characterized in that the filter insert (10) is designed according to one of the preceding claims.

23. Filter unit according to claim 22, characterized by a high-voltage ionizer, wherein the electrical supply module is configured to supply current to the ionizer.

24. A method for producing a filter insert (10), in particular a filter insert (10) according to one of claims 1 to 21, comprising the step: Providing an electrically insulating filter material (14) and at least one electrically conductive polarizing element (16a, 16b) to which an electrical voltage can be applied to polarize the filter material (14); characterized by the step: Creating an elongated electrical conduction path (20) running along a contact surface (22) of the filter insert (10) for energizing the polarization element (16a, 16b).

25. The method according to claim 24, characterized in that the electrical conduction path (20) is created by applying an electrically conductive material to the contacting surface (22); and / or by printing an electrically conductive conductor track onto the contacting surface (22).

26. Method according to claim 24 or 25, characterized in that the contacting surface (22) is surface-treated, in particular thermally surface-treated and / or smoothed, before the electrical conduction path (20) is created.

27. Method according to one of claims 24 to 26, characterized by the step: electrically conductively connecting the electrical conduction path (20) running along the contacting surface (22) to the polarization element (16a, 16b) by means of at least one contacting element (24a, 24b).

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