LASER-SINTERED FILTER, METHOD FOR PRODUCING THE FILTER, AND METHOD FOR ENSURING FLUID FLOW

Abstract

The invention relates to a filter (1) for cleaning fluids, having a main part (2) consisting of polyethylene particles (3) that have been bonded to each other by means of a generative manufacturing process such as to obtain a predefined macro- and microstructure, the main part (2) having regions in which the porosity is deliberately adjusted to varying values. The invention also relates to a method for producing a filter (1), the filter being generatively manufactured by selective laser sintering of polyethylene particles (3). The invention finally relates to a method for ensuring fluid flow.

Claims

1. Filter for cleaning fluids, having a main body made of polyethylene particles which are bonded to each other by means of a generative manufacturing method in such a way that a predefined macrostructure and microstructure is established, wherein the main body has regions in which the porosity is adjusted differently in a targeted manner, wherein the filter has a greater porosity at its surface than in an interior of the filter and/or has a coarse-grained surface structure.

2. Filter according to claim 1, wherein the main body is designed as a laser-sintered component.

3. Filter according to claim 1, wherein the particles of the main body are distributed in layers, wherein the particles of one layer are fused/sintered to each other by means of a laser and the particles from different layers are fused/sintered to each other by means of a laser.

4. Filter according to claim 1, wherein the polyethylene particles and/or the main body of the filter are/is provided with a metal doping and/or a ceramic doping.

5. Filter according to claim 1, wherein the particles of the main body are round, potato-shaped, angular, polyhedron-shaped, chip-shaped and/or oval.

6. Filter according to claim 1, wherein the surface of the main body is plasma-treated.

7. Filter according to claim 1, wherein the main body has undercuts and/or cavities.

8. Method for manufacturing a filter according to claim 1, wherein the filter is generatively manufactured by selective laser sintering of polyethylene particles.

Description

[0035] The invention is explained in the following with the aid of figures. The drawings serve for understanding the invention. Identical elements are characterized by the same reference signs. They show:

[0036] FIG. 1 shows a perspective, enlarged surface view of a filter according to the invention, which is produced by selective laser sintering,

[0037] FIG. 2 shows a schematic representation of a cross-section of the filter of FIG. 1 to illustrate a structure of the filter,

[0038] FIG. 3 shows a perspective, enlarged surface view of a conventional filter made by sintering, and

[0039] FIG. 4 shows a schematic representation of a cross-section of the filter of FIG. 3 to illustrate a structure of the filter.

[0040] FIG. 1 shows a filter 1 according to the invention for cleaning fluids. The filter 1 has a main body 2 composed of polyethylene particles 3. The particles 3 are joined together by means of a generative manufacturing process, in particular by selective laser sintering. In this process, the particles 3 are connected to each other in such a way that a predefined macrostructure and microstructure are formed. A macrostructure or a macroporosity is understood to be a structure of the main body that results from the design. This means, therefore, that the macroporosity in particular can be specifically adjusted in order to define, for example, the outer and/or inner geometry, the appearance, the surface properties and/or the microsection of the main body. A microstructure or microporosity is understood to be a structure in the interior of the main body that is created by the process as a result of manufacturing the filter from a mostly powder-like material. This means, therefore, that the microporosity is determined by process parameters such as a particle size.

[0041] In a comparison of FIG. 1 with FIG. 3, a difference between a filter 1 produced by laser sintering (FIG. 1) and a filter 4 produced by conventional sintering (compare FIG. 3) can be clearly seen. The laser-sintered filter 1 has a rougher surface, since it is applied in layers, in contrast to the compression-molded filter 4, so that a defined structure on the surface is not damaged, for example is not deformed or crushed by the mold. Thus, the macrostructure of the filter 4 produced by conventional sintering cannot be specifically adjusted. The surface structure or surface texture of the filter 1 according to the invention is independent of the mold used to produce the outer geometry.

[0042] The surface of the filter 1 has a defined structure. The structure is formed by the particles 3 which are rounded outwards. The surface of the filter 1 is formed in a scatter-like manner. This means that the particles 3 are round and not flat on the surface. The particles 3 are therefore mechanically non-deformed/undeformed. Interstices are formed between the particles 3, which are open towards the outside. This results in a large surface-to-volume ratio. Preferably, the ratio is greater than 10*1/mm.

[0043] According to the invention, the main body 2 has regions in which the porosity is specifically set differently. The porosity of the main body 2 is not the same in every region of the main body 2, but varies. This means, therefore, that the main body 2 has a different porosity in first regions than in second regions of the main body 2, which are arranged at a distance from the first regions. In a conventionally manufactured filter, the porosity cannot be influenced, but results rather randomly. In particular at the surface of a conventionally manufactured filter, the porosity is reduced by the manufacturing process.

[0044] In particular, the main body 2 may have greater porosity at the surface than at the interior. Due to the higher permeability at the surface, the fluid to be filtered can easily enter the entire main body 2.

[0045] The filter 4 of FIGS. 3 and 4 also has particles 5 arranged to form a surface structure. However, the particles 5 at the surface are mechanically deformed by compression molding. As a result, the spaces at the surface between the individual particles 5 are closed. In contrast to the filter 1, the particles 5 at the surface have flat surfaces. Accordingly, the ratio between the surface area and the volume of the particles 5 is also considerably lower than in the filter 1.