Filter material, filter element with the same, and oil filter

Abstract

The present invention relates to a filter material (1) for a filter element comprising a multilayer composite (5) through which a liquid stream (3) flows, the composite having an absorption layer (6) comprising a water-absorbing material for absorbing water bound in the liquid stream (3), a particle filter layer (7) comprising a nonwoven material for separating particles contained in the liquid stream (3), and a support layer (8) for supporting the absorption layer (6) and the particle filter layer (7). The present invention further relates to a filter element comprising such a filter material and to an oil filter comprising at least one such filter element.

Description

[0001] The present invention relates to a filter material for a filter element according to the subject matter of claim 1. The invention further relates to a filter element with such a filter material and to an oil filter with such a filter element.

[0002] A filter element is designed to remove particles and bound and / or free water from a fluid flow circulating in a closed loop. This water can damage fluid components within the loop, for example through corrosion, or cause electrical short circuits. For this purpose, the filter element is equipped with a filter material through which the fluid flow is permeable. The current challenge lies in further developing this filter material so that it can be produced cost-effectively in large quantities and effectively removes the unwanted substances from the fluid flow.

[0003] Against this background, the object of the present invention is to provide an improved or at least an alternative embodiment of a filter material for a filter element. Furthermore, an advantageous filter element with such a filter material and an advantageous oil filter are to be provided.

[0004] To solve the first-mentioned problem, the invention proposes a novel filter material for a filter element, in particular an oil filter element for an oil filter, which has a multi-layered composite through which a liquid stream can flow, comprising an absorption layer comprising a water-absorbing material for absorbing water bound in the liquid stream, a particle filter layer comprising a nonwoven material for separating particles contained in the liquid stream, and a support layer for supporting the absorption layer and the particle filter layer.

[0005] The invention has recognized that the specified filter material, which could also be called filter composite material, can be produced cost-effectively and, when used in a filter element, can simultaneously separate particles and water bound (i.e. dissolved) in the liquid stream effectively from the liquid stream.

[0006] The term "composite" can be understood, within the meaning of the invention, to mean that the aforementioned layers of the multilayer composite are interconnected and consequently form a cohesive unit. This makes the proposed filter material easy to handle, transport, and store. Furthermore, due to its proposed structure, it can be relatively easily transformed into a predetermined shape, for example, by folding the filter material into a pleated form.

[0007] The fluid flow in question can be, in particular, an oil flow. The oil flow, in turn, can consist of oil or an oil mixture.

[0008] As mentioned at the outset, the liquid stream may contain unwanted water. This water, particularly in the oil stream, may be present as bound water and / or as free water. The invention defines "bound water" as water that is dissolved in the liquid stream, particularly in the oil stream. Furthermore, the invention advantageously defines "free water" as water that is undissolved in the liquid stream, particularly in the oil stream, i.e., in particular as a separate phase. For example, the free water in the liquid stream may be present in the form of water droplets.

[0009] Advantageously, the multilayer composite may have an upstream side facing the liquid flow and an outstream side facing away from the upstream side, wherein the absorption layer is arranged on or forms the upstream side, the support layer is arranged on or forms the outstream side, and the particle filter layer is arranged between the absorption layer and the support layer. Alternatively, the multilayer composite may have an upstream side facing the liquid flow and an outstream side facing away from the upstream side, wherein the particle filter layer is arranged on or forms the upstream side, the support layer is arranged on or forms the outstream side, and the absorption layer is arranged between the particle filter layer and the support layer.This describes two preferred embodiments of the filter material in which the order of the absorption layer and the particle filter layer is reversed with respect to the upstream side. In the first embodiment, the absorption layer is arranged upstream, i.e., it is advantageously directly exposed to the liquid flow. Tests have shown that this allows for the relatively effective removal of water bound (i.e., dissolved) in the liquid flow. In contrast, in the second embodiment, the particle filter layer is arranged upstream, i.e., it is advantageously directly exposed to the liquid flow. This allows for the relatively effective removal of particles contained in the liquid flow.

[0010] Furthermore, the water-absorbing material of the absorption layer can be a superabsorbent polymer, in particular sodium polyacrylate. A superabsorbent polymer (SAP for short) within the meaning of the invention is advantageously a polymer-based material that can absorb water, especially water dissolved in the liquid stream, and store it by converting the material into a gel-like state. It should also be noted that the water-absorbing material can be in powder or bulk form. This allows water bound in the liquid stream, especially the oil stream, to be effectively separated from the liquid stream.

[0011] To ensure that the absorption layer is cost-effective to manufacture and easy to handle, it can be designed to include sublayers, one of which contains the water-absorbing material of the absorption layer. Specifically, it can be designed that a first sublayer, forming a protective layer, is a nonwoven material; a second sublayer, forming a protective layer, is also a nonwoven material; and a third sublayer, forming a functional layer, contains the water-absorbing material of the absorption layer. Furthermore, the functional layer is positioned between the first and second protective layers. This placement protects the functional layer from contact and / or mechanical damage. The protective layers also facilitate easy handling of the functional layer.of the water-absorbing material. Advantageously, the first protective layer and the second protective layer may each have or form at least one pocket for receiving the functional layer or the water-absorbing material, for which purpose the first and second protective layers may, for example, be locally connected to one another, such as by bonding. Furthermore, the sublayers of the absorption layer may form a sublayer composite. The "sublayer composite" within the meaning of the invention may be a composite in which said sublayers are connected to one another and consequently form a coherent structural unit. This makes the absorption layer easy to handle, transport, and store.

[0012] The nonwoven material of the first and second protective layers can be, for example, a plastic nonwoven, in particular a polyethylene nonwoven (PE nonwoven). This allows the first and second protective layers to be produced relatively cost-effectively.

[0013] Furthermore, the nonwoven material of the particle filter layer can be a plastic nonwoven. This plastic nonwoven can be a polyethylene nonwoven. In particular, the plastic nonwoven can be made of or comprise a thermoplastic material. Specifically, polytrimethylene terephthalate (PPT) and / or polyethylene terephthalate (PET) can be used as thermoplastic materials for the plastic nonwoven, resulting in a PPT or PET nonwoven. This allows the nonwoven material to be produced cost-effectively and in large quantities. It should also be noted that the particle filter layer can be made of this nonwoven material.

[0014] It may also be advantageous if the nonwoven material of the particle filter layer has, or is provided with, a permeable open-pore structure. In this case, a pore size of 125 µm or greater and / or an air permeability of the nonwoven material in the range of 1100 L / m² are desirable. 2 s up to 1600 L / m 2 s should be set, where “L” is the volume of the liquid flow in liters, “s” is the time in seconds, and “m” 2 “specifies the size of the area through which the fluid flows through the nonwoven material. The invention has recognized that this allows the particles contained in the liquid flow to be effectively separated from the liquid flow and, at the same time, favorable flowability through the nonwoven material can be achieved with a relatively low pressure loss.

[0015] In particular, the support layer can comprise or be formed from a grid-like material that supports the absorption layer and the particle filter layer. The support layer, especially said grid-like material of the support layer, is designed to impart mechanical strength to the filter material, ensuring both safe handling and manufacturing of the filter material and sufficient resistance of the filter material to differential pressure generated when flowing through it, i.e., when it is used in a filter element. The support layer or the grid-like material of the support layer can have a mesh size larger than that of the nonwoven material of the particle filter layer. The mesh size of the support layer or the mesh size of the grid-like material of the support layer can be in the range of 1.5 mm to 2 mm, or preferably 1.7 mm.Furthermore, the invention has recognized that the grid-like material of the support layer provides a certain drainage effect.

[0016] To ensure that the multilayer composite forms a cohesive unit, as mentioned earlier, it is advantageous for the absorption layer, the particle filter layer, and the support layer to be bonded together, at least in sections, particularly along the edges of the filter material. A hot melt adhesive, for example, can be used to bond these layers. This ensures that the absorption layer, the particle filter layer, and the support layer are permanently fixed to one another.

[0017] Alternatively, and / or in a particularly lightweight and cost-effective embodiment of the filter material, the absorption layer, the particle filter layer, and the support layer can be fixed to one another, at least partially, and in particular exclusively, by friction. This ensures that the layers are fixed in place. The frictional connection of the absorption layer, the particle filter layer, and the support layer can be achieved, for example, by applying the absorption layer and the particle filter layer to the support layer with a certain preload, so that the absorption layer and the particle filter layer adhere to the support layer by static friction. In this embodiment, adhesives or other bonding agents can be omitted, thus providing, as mentioned, a lightweight and cost-effective embodiment of the filter material.

[0018] The second problem mentioned at the outset is solved by a filter element, particularly for an oil filter, comprising a filter material designed according to the preceding description. This provides an advantageous filter element, especially one that is cost-effective and lightweight. In this context, it may be advantageous if the filter material is folded in a zigzag pattern and / or designed as a pleated star and / or is arranged in a housing of the filter element as a filter stage for separating particles and bound water from the liquid stream, particularly as a pleated star. It is conceivable that, in addition to the aforementioned filter stage, the filter element may also have a further filter stage for separating free water, for example, water droplets, from the liquid stream.

[0019] The problem mentioned last at the beginning is solved by an oil filter with at least one filter element designed according to the preceding description. This provides an advantageous oil filter, particularly one that is cost-effective and lightweight.

[0020] In summary, the present invention advantageously relates to a filter material for a filter element comprising a multilayer composite through which a liquid stream flows, comprising an absorption layer (a water-absorbing material for absorbing water bound in the liquid stream), a particle filter layer (a nonwoven material for separating particles contained in the liquid stream), and a support layer for supporting the absorption layer and the particle filter layer. The present invention further relates to a filter element comprising such a filter material and to an oil filter comprising at least one such filter element.

[0021] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0022] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention. The components of a higher-level unit, such as a device, apparatus, or arrangement, mentioned above and those to be mentioned below, which are designated separately, can form separate parts or components of this unit or be integral areas or sections of this unit, even if this is depicted differently in the drawings.

[0023] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0024] Each of these shows, schematically, Fig. 1 in a sectional view a section of a filter material according to the invention in a first embodiment, Fig. 2 in a sectional view a section of a filter material according to the invention in a second embodiment and lastly Fig. 3 also in a sectional view a greatly enlarged representation of an absorption layer of the filter material according to the in Fig. 1 or Fig. 2 illustrated embodiment, wherein the remaining layers of the filter material are hidden.

[0025] The Fig. 1 and Fig. Figures 2 and 2 each show a section of a filter material, designated as 1 in its entirety, for a filter element not shown. The filter element can be used, for example, in an oil filter (also not illustrated) to separate particles, bound water, and / or free water from a fluid flow 3 circulating in a circuit, in particular an oil flow consisting of oil or an oil mixture. This free water can damage components fluidly integrated into the circuit, for example, through corrosion, or cause electrical short circuits.

[0026] The filter material 1 has a continuous, multi-layered composite 5, which is separated from the liquid stream 3 in a Fig. 1 and Fig. 2 each flow direction 4 indicated by an arrow is permeable or is permeated. The multilayer composite 5 thus has an upstream side 9 directly accessible to the liquid flow 3, which can be assigned to a raw space of the filter element (not illustrated), and an outflow side 10 facing away from the upstream side 9, which can consequently be assigned to a clean space of the filter element.

[0027] In order for the filter material 1 to be cost-effective to produce and, when used in the filter element, to effectively separate particles from the liquid stream 3 and water bound (i.e. dissolved) in the liquid stream 3, it is necessary in the present embodiment according to Fig. 1 as well as in the embodiment according to Fig. 2 provided that the composite 5 has an absorption layer 6 comprising a water-absorbing material for absorbing (i.e. taking up) water bound (i.e. dissolved) in the liquid stream 3, a particle filter layer 7 comprising a nonwoven material for separating particles contained in the liquid stream 3 and a support layer 8 for supporting the absorption layer 6 and the particle filter layer 7.

[0028] The water-absorbing material of the absorption layer 6 can be a superabsorbent, in particular sodium polyacrylate. The nonwoven material of the particle filter layer 7 is preferably a plastic nonwoven with a permeable open-pore or grid-like structure. Furthermore, the support layer 8 has or is formed from an open-pore or grid-like material that is designed to support the absorption layer 6 and the particle filter layer 7. It should also be noted that in the present case, i.e., both in the Fig. 1 as shown as well as in the Fig. In the embodiment shown in Figure 2, the absorption layer 6, the particle filter layer 7 and the support layer 8 are at least partially frictionally fixed to one another, so that the said layers 6, 7, 8 are fixed to one another without adhesive or other connecting means.

[0029] In Fig. 1 and Fig. 2. It is further evident that the layers 6, 7, 8 of the filter material 1 have different layer thicknesses along the flow direction 4. It is advantageous if a layer thickness of the absorption layer 6 along the flow direction 4 is greater than a layer thickness of the support layer 8 along the flow direction 4 and / or a layer thickness of the support layer 8 along the flow direction 4 is greater than a layer thickness of the particle filter layer 7 along the flow direction 4.

[0030] The in Fig. The embodiment of the filter material 1 shown in Figure 1 is characterized in particular by the sequence of its layers 6, 7, 8 along the flow direction 4. Specifically, the absorption layer 6 is arranged on the upstream side 9 of the filter material 1, and the support layer 8 is arranged on the downstream side 10 of the filter material 1. Furthermore, the particle filter layer 7 is arranged between the absorption layer 6 and the support layer 8 along the flow direction 4. This allows the upstream absorption layer 6 to be directly exposed to the liquid flow 3, thereby enabling the relatively effective separation of the water bound (i.e., dissolved) in the liquid flow 3 from the liquid flow 3.

[0031] The in Fig. The embodiment of the filter material 1 shown in Figure 2 relates to an alternative arrangement of the layers 6, 7, and 8. Specifically, the particle filter layer 7 is arranged on the upstream side 9 of the filter material 1, and the support layer 8 is again located on the downstream side 10 of the filter material 1. The absorption layer 6 is arranged along the flow direction 4 between the particle filter layer 7 and the support layer 8. This means that the upstream particle filter layer 7 is directly exposed to the liquid flow 3, allowing the particles contained in the liquid flow 3 to be separated from it relatively effectively.

[0032] The Fig. Figure 3 shows a highly magnified cross-sectional view of the absorption layer 6 of the filter material 1 according to the [reference to be added]. Fig. 1 or Fig.In the illustrated embodiment shown in Figure 2, the remaining layers 7, 8 of the filter material 1 are omitted for simplicity. The absorption layer 6 comprises a continuous arrangement 11 of several stacked sublayers 12, 13, 14. A first sublayer 12, 13, 14 is designed as a first protective layer 12. A second sublayer 12, 13, 14 is designed as a second protective layer 13. The first and second protective layers 12, 13 are made of or comprise a nonwoven material, thereby effectively protecting a third sublayer 12, 13, 14, which, as a functional layer 14, comprises the water-absorbing material of the absorption layer 6 and is arranged between the first protective layer 12 and the second protective layer 13, from contact and / or mechanical damage. Reference symbol list 1 filter material 3. Fluid flow 4 Flow direction 5 network 6 Absorption position 7 Particle filter layer 8 Support position 9 Upstream side 10 Outflow side 11. Arrangement 12 first protective layer 13 second layer of protection 14 Functional position

Claims

[1] Filter material (1) comprising a filter element - comprising a multi-layered composite (5) through which a liquid stream (3) can flow, comprising an absorption layer (6) comprising a water-absorbing material for absorbing water bound in the liquid stream (3), a particle filter layer (7) comprising a nonwoven material for separating particles contained in the liquid stream (3), and a support layer (8) for supporting the absorption layer (6) and the particle filter layer (7). [2] Filter material (1) according to claim 1, characterized by , that - the multilayer composite (5) has an upstream side (9) that can be approached by the liquid flow (3) and an outflow side (10) that is turned away from the upstream side (9), - wherein the absorption layer (6) is arranged on or forms the upstream side (9), - wherein the support position (8) is arranged on or forms the outflow side (10), and - wherein the particle filter layer (7) is arranged between the absorption layer (6) and the support layer (8). [3] Filter material (1) according to claim 1, characterized by , that - the multilayer composite (5) has an upstream side (9) that can be approached by the liquid flow (3) and an outflow side (10) that is turned away from the upstream side (9), - wherein the particle filter layer (7) is arranged on or forms the upstream side (9), - wherein the support position (8) is arranged on or forms the outflow side (10), and - wherein the absorption layer (6) is arranged between the particle filter layer (7) and the support layer (8). [4] Filter material (1) according to any one of the preceding claims, characterized by , that - the water-absorbing material of the absorption layer (6) is a superabsorber, in particular sodium polyacrylate or sodium polyacrylate. [5] Filter material (1) according to any one of the preceding claims, characterized by , that - the absorption layer (6) has an arrangement (11) of sublayers (12, 13, 14), one of which sublayers (14) has the water-absorbing material of the absorption layer (6). [6] Filter material (1) according to claim 5, characterized by , that - a first of the sublayers (12, 13, 14) comprising a nonwoven material as a first protective layer (12), - a second of the sublayers (12, 13, 14) having a second protective layer (13) consisting of a nonwoven material, - a third of the sublayers (12, 13, 14) having a functional layer (14) in which the water-absorbing material of the absorption layer (6) is formed, - wherein the functional position (14) is arranged between the first protective position (12) and the second protective position (13). [7] Filter material (1) according to any of the preceding claims, characterized by , that - the nonwoven material of the particle filter layer (7) is a plastic nonwoven. [8] Filter material (1) according to any of the preceding claims, characterized by , that - the nonwoven material of the particle filter layer (7) has a permeable open-pore structure or is provided with such an open-pore structure, - wherein the pore size of the pores of the nonwoven material is 125 µm or greater than 125 µm and / or the air permeability of the nonwoven material is in the range of 1100 L / m 2 s up to 1600 L / m 2 s lies. [9] Filter material (1) according to any of the preceding claims, characterized by , that - the support layer (8) has or is formed of a grid-like material that supports the absorption layer (6) and the particle filter layer (7), - wherein optionally a mesh size of the support layer (8) or a mesh size of the grid-like material of the support layer (8) is in a range of 1.5 mm to 2 mm or preferably 1.7 mm. [10] Filter material (1) according to any of the preceding claims, characterized by , that - the absorption layer (6), the particle filter layer (7) and the support layer (8) are bonded together at least in sections. [11] Filter material (1) according to any of the preceding claims, characterized by , that - the absorption layer (6), the particle filter layer (7) and the support layer (8) are at least partially frictionally fixed to one another. [12] Filter element, in particular a pleated star, for in particular an oil filter, comprising a filter material (1) designed according to one of the preceding claims. [13] Filter element according to claim 12, characterized by , that - the filter material (1) is folded in a zigzag shape and / or is designed as a pleated star arranged in a housing of the filter element. [14] Oil filter with at least one filter element according to claim 12 or 13.

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