DE102022210893A1 - Method for producing a filter molding - Google Patents

Abstract

The present invention relates to a method for producing a filter molding (100) with a filter (101) having an opening width in the micrometer range, comprising:- providing (305) a material; and- 3D printing (307) the material into the shape of the filter molding (100).

Description

The present invention relates to a method for producing a filter molding, in particular with a filter having an opening width in the micrometer range.

Previous conventional manufacturing processes for small-scale filter moldings include a comparatively high number of manufacturing steps, which include forming, separating (e.g. machining) and joining process steps for machining the workpiece as well as corresponding preparation steps for carrying out these process steps (e.g. alignment, positioning, etc.). Such complex manufacturing processes can lead to high unit costs and/or long production times.

Furthermore, conventional manufacturing processes also limit the design freedom of small-scale filter moldings, such as the properties of a filter (sieve) of the filter moldings.

The object of the present invention is to provide a method which at least partially overcomes the above-mentioned disadvantages.

This object is achieved by a method according to claim 1. Further advantageous embodiments of the invention emerge from the subclaims and the following description of preferred embodiments of the present invention.

• - Bereitstellen eines Materials; und
• - 3D-Drucken des Materials in die Form des Filterformteils.

According to a first aspect, the present invention provides a method for producing a filter molding with a filter having an opening width in the micrometer range. The method comprises:

• - Providing a material; and
• - 3D printing the material into the shape of the filter molding.

The filter molding is a component in the form of a plug or a cylinder that can be inserted into a passage channel of a component. The cross-section of the filter molding can be, for example, round, oval, rectangular, star-shaped, etc. The component is in fluid communication with the environment via the passage channel and the filter molding filters impurities, particles, or the like from a fluid flow through the passage channel. For this purpose, the filter molding comprises a filter (sieve) with an opening width (mesh width) in the micrometer range. The opening width corresponds to the size of the (clear) openings of the filter. The opening width can be at least 50 µm or larger, e.g. 125 µm.

In some examples, the filter molding may have a length of 7 to 11 mm, e.g. 9 mm, and/or a diameter of 7 to 9 mm, e.g. 8 mm.

The present method is directed to providing the filter molding using a 3D printing method. In the context of the present disclosures, the 3D printing method corresponds to a manufacturing method in which the (manufacturing) material is applied layer by layer to produce the (three-dimensional) filter molding. The “3D printing method” can also be referred to as an additive/generative manufacturing method or rapid technology.

The method includes providing the material. The material is suitable for 3D printing processes. For example, the material can be based on stainless steel such as “BASF Ultrafuse 316L”. In other examples, plastic can also be used. In principle, materials are possible that are suitable for the 3D printing described below. For example, materials that can be processed into filaments and used for 3D printing can generally be used.

The method further includes 3D printing the material into the shape of the filter molding. In some examples, the 3D printing may be done via fused deposition modeling (also known as fused filament fabrication, FDM, or FFF). In some examples, the 3D printing may be used to create a green part in the shape of the filter molding. The green part may be further processed (as described below) to form the filter molding.

With the process described above, it is possible to produce the filter molding faster and more cost-effectively than with the conventional manufacturing processes mentioned above.

Furthermore, it has been found that an effective filter surface of the filter molding can be dimensioned and manufactured to be larger than that of a similar filter molding produced using conventional manufacturing processes. The process described above therefore enables the production of filter moldings with improved filter properties and greater design freedom for the filter molding.

Furthermore, 3D printing allows the filter molding to be manufactured in one piece (monolithic), which improves the stability of the filter molding.

Material waste is also reduced by eliminating machining steps.

• - Entbindern (309) des Filterformteils (100); und
• - Sintern (311) des Filterformteils (100).

In further embodiments, the method may further comprise:

• - debinding (309) of the filter molding (100); and
• - Sintering (311) of the filter molding (100).

These steps are necessary when using certain materials, especially when a green compact in the form of the filter molding is produced using 3D printing. The green compact is debinding and sintering is carried out to produce the filter molding.

In other embodiments, the debinding can be carried out using an acid. Nitric acid, for example, can be used. This allows the debinding to be carried out more quickly.

In further embodiments, debinding can take place in a temperature range of 100°C to 140°C, in particular at a temperature of 120°C. Debinding in this temperature range is particularly suitable for materials based on stainless steel.

In other embodiments, sintering (of the green compact) can be carried out under vacuum. This can improve properties such as surface quality and mechanical properties of the filter molding.

In further embodiments, the sintering (of the green compact) can take place in a temperature range of 1200°C to 1400°C, in particular at a temperature of 1380°C. It has been found that with these process parameters, the sintering of the molded part (or the green compact) can be improved, in particular if the material used is based on stainless steel. An exemplary sintering process can comprise three phases. In the first phase, a sintering device (e.g. a (blast) furnace) is heated from room temperature to 600°C (e.g. with a temperature increase of 5 Kelvin per minute) and held there for one hour. In the second phase, the sintering device is heated from 600°C to 1380°C (e.g. with a temperature increase of 5 Kelvin per minute) and held there for three hours. The third phase corresponds to a cooling phase.

In other examples, depending on the material used, a different temperature range may be selected, which includes a temperature just before the melting point of the material used.

• - Erstellen eines 3D-Modells des Filterformteils; und
• - Umwandeln des 3D-Modells in ein Schichtmodell (bzw. in Schichten) zum 3D-Drucken (des Filterformteils bzw. des Grünlings).

In some embodiments, the method may further comprise:

• - Creating a 3D model of the filter molding; and
• - Converting the 3D model into a layered model (or layers) for 3D printing (of the filter molding or the green part).

The 3D model can be created using a CAD program, for example. The 3D model is then converted into layers for 3D printing, using slicer software, for example. The slicer software converts the 3D model into specific instructions for a 3D printing device.

In some examples, the green compact can be larger than the 3D model by a predetermined factor (e.g. 1.2). This allows shrinkage of the green compact during sintering to be taken into account.

• 1a, b schematisch eine Seiten- und Perspektivansicht eines Filterformteils;
• 2 schematisch eine Schnittansicht des Filterformteils aus 1a, b in einem eingebauten Zustand;
• 3 ein Verfahren zum Herstellen des Filterformteils aus 1a, b;
• 4a, b das Filterformteil aus 1a, b und ein konventionell hergestelltes Filterformteil.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

• 1a , b schematically shows a side and perspective view of a filter molding;
• 2 schematically a sectional view of the filter molding from 1a , b in an installed state;
• 3 a method for producing the filter molding from 1a , b;
• 4a , b the filter molding made of 1a , b and a conventionally manufactured filter molding.

1a and 1b schematically represent a filter molding 100. 1a a side view and 1b a partially sectioned perspective view. The filter molding 100 has a cylindrical shape and comprises a filter (sieve) 101 at a first (front) end 111 and an outlet opening 103 at a second (front) end 117. The filter 101 can have an opening width of 100 µm to 150 µm, for example 125 µm. The filter 103 rests on the first front end 111 from the outside or covers the first front end 111.

On an outer peripheral side, the filter molding 100 comprises a sealing portion 105 which, in an installed state of the filter molding 100, is in contact with a contact surface 205a of a (in 2 shown) hollow shaft element 200. The filter molding 100 shown has a length L of 9 mm and a diameter D of 8 mm.

In 2 a sectional view is shown in which the filter molding 100 is inserted into the shaft element 200. The contact surface 205a of the shaft element 200 corresponds to an inner peripheral surface a cavity (passage channel) 205 of the shaft element 200.

Returning to 1a , b the filter molding 100 further comprises a chamfer 107 on the side of the first front end 11. An angle α of the chamfer 107 can be from 55° to 65°, e.g. 60°.

In 1b It can be seen that the filter molding 100 comprises a passage opening 109 at its first front end 111, which is provided for pressure regulation (e.g. pressure reduction) of a fluid. The diameter of the passage opening 109 can vary depending on the application. In some applications, the diameter can be from 0.3 mm to 0.5 mm, e.g. 0.4 mm. In the installed state (see 2 ), the fluid flows through the filter molding 100 from the filter 101 in the direction of the outlet opening 103.

An (optional) support 113 for stabilizing the filter molding 100 extends between the first front end 111 (which corresponds to a bottom of the cylindrical filter molding 100) and an inner peripheral side of the filter molding 100.

Furthermore, the filter molding 100 comprises at least one (optional) slot 115 on the casing side, which extends in the longitudinal direction of the filter molding 100 and is arranged in the region of the sealing section 105. In other examples in which a plurality of slots 115 are provided, the slots 115 are arranged in the circumferential direction (optionally uniformly) of the filter molding 100.

3 shows a method for producing a filter molding, such as the filter molding 100 described above from 1a , b.

In 301 a 3D model of the filter molding 100 is created.

In 303, the 3D model is converted into layers (or into a layer model) for 3D printing the filter molding 100 or the green body. The resulting layer model can be larger than the 3D model by a predetermined factor, e.g. 1.2, so that shrinkage of the green body during sintering is taken into account and the (final) filter molding 100 is the same size as the 3D model.

In 305, a material is provided for producing the filter molding 100 or the green compact for the filter molding 100.

In 307, the material provided is brought into the shape of the filter molding 100 by means of 3D printing. In other words, the green part for the filter molding 100 is produced by means of 3D printing. The 3D printing is carried out using a corresponding device for 3D printing. Furthermore, the 3D printing follows based on the 3D model and therefore also based on the layer model of the filter molding 100.

In 309, the filter molding 100 or the green part is debound. This can be done with the help of acid. Furthermore, debound can be done in a temperature range of 100°C to 140°C.

In 311, the filter molding 100 is sintered. The green body can be sintered in a temperature range of 1200°C to 1400°C to produce the filter molding.

4a and 4b show the filter molding 100 produced using the method according to the invention or a conventional filter molding 100' (ie produced using conventional production methods).

The conventional filter molding 100' and the filter molding 100 are essentially constructed in the same way, but differ in the structure of the filter 101, 101'. A filter surface 101a of the filter 101 of the filter molding 100 is larger than a filter surface 101a' of the filter 101' of the conventional filter molding 100'.

Reference symbols

100

Filter molding

100'

conventional filter molding

101

Filter/sieve

101'

Filter/sieve

101a

Filter area

101a'

conventional filter area

103

Outlet opening

105

Connecting section

107

chamfer

109

Passage opening

111

first front end

113

support

115

slot

117

second front end

200

Shaft element

205

Passage channel/cavity

205a

Contact surface

300

Method for producing a filter molding

301

Creating a 3D model of the filter molding

303

Converting the 3D model into layers

305

Providing a material;

307

3D printing the material into the shape of the filter molding;

309

Debinding

311

Sintering

α

angle

d

diameter

L

length

Claims (8)

Method (300) for producing a filter molding (100) with a filter (101) having an opening width in the micrometer range, comprising: - providing (305) a material; and - 3D printing (307) the material into the shape of the filter molding (100). Procedure (300) according to Claim 1 , further comprising: - debinding (309) of the filter molding (100); and - sintering (311) of the filter molding (100). Procedure (300) according to Claim 2 , wherein the debinding (309) is carried out using an acid. Method (300) according to one of the Claims 2 or 3 , wherein the debinding (309) takes place in a temperature range of 100°C to 140°C, in particular at a temperature of 120°C. Method (300) according to one of the Claims 2 until 4 , wherein the sintering (311) takes place under vacuum. Method (300) according to a Claims 2 until 5 , wherein the sintering (311) takes place in a temperature range of 1200°C to 1400°C, in particular at a temperature of 1380°C. Method (300) according to one of the Claims 2 until 6 , further comprising: - creating (301) a 3D model of the filter molding (100); and - converting (303) the 3D model into a layer model for 3D printing. Method (300) according to one of the Claims 2 until 7 , the material is based on stainless steel.

Images