Method and screen for producing a screen body

Abstract

The present invention relates to a method for producing a screen body, which includes one or more openings (18) on a screen surface (5), in particular the screen body of a screen (1) for use in a screw press (10). In order to achieve a particularly long service life, it is provided according to the present invention that the screen body is formed by a sintering process and / or an additive manufacturing process, in particular a 3D printing process. The present invention further relates to a screen (1) having a screen body that includes one or more openings (18) on a screen surface (5), in particular the screen (1) for a screw press (10).

Description

Technical Field

[0001] The present invention relates to a method for producing a screen body, which includes one or more openings on the screen surface, in particular a screen body of a screen for use in a screw press.

[0002] The present invention further relates to a screen having a screen body that includes one or more openings on the screen surface, in particular a screen for a screw press. Background Art

[0003] Screw presses are well known from the prior art. This type of screw press is used to separate liquid from, for example, a transport material, and includes a screw conveyor arranged in a spiral shape on a driven worm shaft, and a housing shell surrounding the conveyor, wherein a transport channel for the transport material being conveyed is implemented between the worm shaft and the housing shell and is partially bounded by the screw conveyor so that, during rotation of the worm shaft, the transport material is conveyed along the longitudinal axis of the screw press through the transport channel by means of the screw conveyor. The housing shell thus typically includes openings so that, via the pressure applied thereto during the transport of the transport material, the liquid is separated from the transport material and is conveyed out of the transport channel through the openings in order to dry the transport material during its movement along the longitudinal axis through the screw press. The openings are thus typically introduced into a metal sheet that serves as a screen, which is part of the housing shell. The screen is formed according to the prior art, wherein drill holes are introduced into the metal sheet. Since the metal sheet has a cylindrical profile, this requires great effort.

[0004] The normal operation of the screw press thus depends on the one hand on the friction between the transport material and the worm shaft or the screw conveyor arranged on the worm shaft, and on the other hand on the friction between the transport material and the inner surface of the housing shell, which is typically a screen implemented as a metal sheet, relative to which the worm shaft is rotatably driven during operation. If the friction between the transport material and the interior of the housing shell drops below a defined threshold, the transport material is not conveyed along the longitudinal direction of the worm shaft during rotation of the worm shaft, but instead only moves rotationally around the longitudinal axis and relative to the housing together with the worm shaft and the screw conveyor, so that the drying of the transport material does not occur and the corresponding process stops.

[0005] According to the prior art, the outer housing generally includes a metal screen having a defined minimum roughness when installed in new conditions in order to ensure a corresponding friction between the conveyed material and the outer housing. However, it has been shown that during operation, the conveyed material, which can consist, for example, of a slurry, sliding continuously along the metal screen causes wear of the screen, which in turn reduces the roughness of the metal screen. As a result, due to surface wear of the metal screen, operation of the screw press over a longer period of time results in improper operation of the screw press due to insufficient friction. Summary of the Invention

[0006] This is solved by the present invention. The object of the present invention is to specify a method of the type described at the beginning for producing a screen body which, when used in the outer housing of a screw press, allows the screw press to operate properly for an especially long period of time and is at the same time easy to produce.

[0007] Furthermore, a screen of the type described at the beginning should be specified which, when used in the outer housing of a screw press, enables the screw press to operate for an especially long period of time.

[0008] According to the present invention, the first object is achieved by a method of the type described at the beginning, in which the screen body is formed by a sintering process and / or an additive manufacturing process, in particular a 3D printing process.

[0009] In the course of the present invention, it has been found that materials formed by a sintering process and / or an additive manufacturing process (in particular such as a 3D printing process) exhibit a constant surface roughness, that is, even when a part of the surface is removed (for example due to abrasive wear). It has been found that this effect occurs due to the manufacturing process and is not limited to a specific material. In other words: contrary to screens formed by conventional methods, which can be implemented, for example, as metal sheets, in the case of the screen body produced according to the present invention, it is no longer possible during operation, for example, to polish the surface in such a way that the roughness decreases to the value necessary for normal operation by wear of the surface layer.

[0010] In addition, the corresponding manufacturing processes are advantageous, especially since widely different geometries can be produced in a simple manner, while the geometries of the screens from the prior art are usually predefined by the tools for producing the screens and cannot be changed without difficulty. As a result, particularly suitable screens can be easily formed, for example, for the various operating conditions of a screw press, such as, for example, the different compositions of the conveyed material to be dried, whereby this type of drying process can be implemented particularly efficiently. In addition, screens with different hole geometries for different positions on the screw press can also be easily produced, for example, in order to adapt the open surface of the screen to the dry content of the conveyed material being dried, which varies along the length of the screw press.

[0011] Typically, the corresponding material has a predetermined porosity such that even if the material on the surface is removed, it still results in the roughness of the new surface.

[0012] In addition, with this type of method, it is also easy to form a material containing harder and softer particles. Via the material containing harder and softer particles, even in the case of wear, the defined roughness can be obtained again. This can be achieved, for example, during the 3D printing process via different boundary conditions (especially different temperatures, and / or different starting materials used during fabrication).

[0013] It is beneficial if the screen body is formed of a plastic, metal, or ceramic material. This type of material has proven to be particularly beneficial for use in a sintering process or an additive manufacturing process for forming the corresponding body. In this case, via the material composition and the parameters of the manufacturing process, the defined porosity of the material, or the roughness obtained even when the surface is removed, can also be easily ensured if necessary.

[0014] The use of lightweight materials (such as, for example, plastics) also has the particular advantage that the replacement of the corresponding screen in a screw press is much easier than that of heavy metal parts. In addition, plastics generally exhibit a lower coefficient of thermal expansion than metals, such that the thermal expansion or thermal stress occurring between stop and operation due to the usually high operating temperature of the screw press (for example, 90 °C) is also reduced.

[0015] If plastics are used, it is particularly beneficial to use plastics having a Shore hardness D greater than 50, especially approximately 75, in order to obtain a particularly long service life when used in a screw press.

[0016] In order to obtain high strength and high rigidity, it can be specified that when the screen body is being formed, fibers are incorporated into and / or formed in the screen body. For example, glass fibers or carbon fibers can thus be incorporated into the screen body.

[0017] In order to obtain particularly beneficial mechanical properties of the screen body while obtaining the beneficial roughness of the screen body, it can be specified that the screen body is formed of different materials in terms of thickness. Different material properties can thus be easily obtained in terms of thickness (i.e., along the direction perpendicular to the screen surface). For example, in a region spaced apart from the screen surface, a material having higher strength and / or higher rigidity than on the screen surface can thus be used, for example, to achieve only slight deformation even under the pressures generally prevailing in a screw press, such as 1 bar to 10 bar, and a temperature of, for example, 90 °C, and at the same time ensure the desired roughness on the screen surface.

[0018] In this case, it is particularly advantageous if the screen body is formed from a first material constituting the screen surface and a second material constituting a region of the screen body spaced apart from the screen surface, wherein the second material has a higher rigidity than the first material.

[0019] Furthermore, it is preferably provided that the screen body is at least partially formed from a material that is dimensionally stable at a temperature of at least 45 °C, in particular at a temperature of at least 90 °C and a pressure load of 1.5 N / mm 2 of the pressure load.

[0020] Preferably, a material having a tensile modulus of at least 800 N / mm 2 and / or a tensile strength of at least 20 N / mm 2 is used.

[0021] To achieve particularly low thermal stress and thermal expansion, it is advantageous if a material having a longitudinal expansion coefficient of less than 0.0005, in particular less than 0.0002, is used.

[0022] Generally, the screen body is formed from a material suitable for use in a humid environment having a pH of 6 to 9 in order to obtain a particularly long service life when used in a screw press.

[0023] Furthermore, if the screen body is formed from a material having a dry content of 3% to 40% of the material suitable for conveyance in a screw press, the use of the screen body in a screw press in which slurries, foods, and / or sludge are dried is particularly advantageous.

[0024] In principle, a wide variety of metallic, plastic, and ceramic materials can be used to form the corresponding screen body. It is particularly preferred if a plastic commercially available under the name aseTK49 from asetec GmbH of Rastenfeld, Austria, and available as of the filing date is used, especially since this plastic exhibits beneficial mechanical properties for use in a screw press.

[0025] It has been shown that the material aseTK49 is particularly suitable for the corresponding screen body, especially since the material has a tensile modulus of approximately 1650 N / mm 2 a limiting elongation of approximately 15%, a resistance to deformation at 1.5 N / mm 2 and 90 °C and 0.4 N / mm 2 and 150 °C, a tensile strength of approximately 40 N / mm 2 and a compressive strength of approximately 65 N / mm 2Compressive strength, and at the same time, a structure is formed that ensures substantially constant roughness even in the case of wear. In addition, the material is suitable for use in a screw press under correspondingly moist conditions at the prevailing pH levels.

[0026] It has proven effective that one or more openings are formed during the sintering process and / or the additive manufacturing process. This results in a particularly simple method even compared to the conventional production of corresponding sieves, in which multiple holes are typically drilled into a metal sheet to form the sieve. As part of the additive manufacturing process or the sintering process, the hole geometry can also be easily implemented, where the cross-section of the hole or opening increases from the inside to the outside to avoid clogging of the opening. Additionally, even non-perfectly circular openings can, in principle, be easily formed, such that there are no limitations in this regard, although openings with a circular cross-section are preferred.

[0027] According to the invention, a sieve that can be used, for example, in a screw press is typically formed using a sieve body implemented according to the invention. The sieve generally includes fastening means by which the sieve can be connected to, for example, a frame, a sieve basket frame, etc., in order to detachably arrange the sieve in, for example, the housing of a screw press. In principle, the sieve can consist only of the sieve body, or it can also include the sieve body as a separate body, together with, for example, additional components that can be used to fasten the sieve body in the screw press.

[0028] According to the invention, another object is achieved using a sieve of the type described at the beginning, in which the sieve body consists of a material formed by a sintering process and / or an additive manufacturing process (in particular a 3D printing process), where the sieve is produced, in particular, by the method according to the invention.

[0029] Using the corresponding sieve, a particularly long operation of a screw press or other equipment where a consistent friction value of the surface of the sieve, or a consistent roughness of the surface of the sieve, is advantageous can be easily ensured, especially since the corresponding roughness is still ensured even in the case of partial wear of the surface. According to the invention, at least the sieve body of the sieve (i.e., the part of the sieve that includes the sieve surface with openings) is implemented accordingly. Of course, in principle, it can also be provided that the sieve is completely formed by the corresponding method and is implemented as one piece with the sieve body.

[0030] It is beneficial if the screen body has a defined porosity that is substantially constant up to a defined depth (in particular a depth of at least 1 mm). This ensures that the desired roughness is always present on the surface even in the case of a corresponding wear level. Starting from a wear level beyond the defined depth (i.e., beyond a defined distance from the screen surface), the replacement of the screen or the screen body must generally occur anyway because the distance between the screw conveyor and the housing shell would otherwise become too large.

[0031] Preferably, it is provided that the screen is implemented as part of a substantially rotationally symmetric body, in particular as part of the shell of a cylinder or a cone, so that a plurality of identical screens can be combined to form a substantially rotationally symmetric body. In this way, the screen can be implemented, for example, as a tile on the inner surface of a cylindrical housing shell, so that the housing shell of a very large screw press can also be formed by correspondingly produced screens. Additionally, a defective screen can then also be replaced in a very simple manner. The screen is generally implemented as thin-walled.

[0032] In addition to the screen body, the screen generally also includes means for being connected (preferably in a detachable manner) to a frame or the like. The means can be implemented, for example, as openings through which the screen can be connected to the frame by means of screws.

[0033] Preferably, it is provided that on at least one lateral edge, recesses are provided, in particular folding seams or chamfers, so that the screen can be positively fixed in place, especially in a direction perpendicular to the screen surface. This enables the screen to be fixed particularly simply in the appropriate position in the frame of the screw press or in the support basket. For example, a T-shaped connecting rail can be provided, which corresponds to the folding seam arranged on the edge of the screen, so that the screen can be positively connected to the frame or the support basket by tightening the T-shaped fastening means.

[0034] It is beneficial if grooves are provided on a first side surface that is preferably arranged substantially perpendicular to the screen surface. The screen can then be easily coupled to another screen or a frame via the side surface.

[0035] It has proven effective to arrange protrusions corresponding to the grooves on a second side surface that is preferably substantially parallel to the first side surface, so that two correspondingly implemented screens can be positively and / or press-fittedly connected by means of the protrusions and the grooves, via the first side surface and the second side surface, in particular by means of a snap connection. For this purpose, it can be provided that the protrusions are implemented with indentations so that the protrusions can engage in the correspondingly implemented grooves.

[0036] For use in a screw press, the corresponding screen is usually implemented as part of a flat, preferably cylindrical or conical housing surface, such that the corresponding outer housing of the screw press (which serves as the screen) can be formed from a plurality of screens connected to one another. If the screens can be connected to one another form - fit or press - fit, in particular by means of snap connections, the installation and removal of the corresponding screens is particularly simple.

[0037] In a screw press for separating liquid from a transport material, having a worm shaft together with a screw conveyor and an outer housing surrounding the conveyor, the screw conveyor is arranged helically on the worm shaft, wherein a transport channel for the transport material being conveyed is implemented between the worm shaft and the outer housing, and wherein the outer housing includes at least one screen such that the liquid separated from the transport material can be conveyed through the outer housing, it is advantageous if the screen is implemented according to the present invention.

[0038] As a result, the operating life of the screw press is particularly long and it is possible for the screw press to be free of functional damage, especially since normal operation can be ensured even in the case of wear of the surface layer of the screen body.

[0039] Advantageously, it is provided that the screen extends only over a part of the circumference of the outer housing, which is implemented as substantially rotationally symmetric, in particular in the shape of a cylinder or a frustum. On the one hand, this simplifies the production of the screen. On the other hand, a defective screen can then also be easily replaced without replacing the entire outer housing.

[0040] Preferably, it is provided that a plurality of identical screens are provided, which are connected to one another form - fit and / or press - fit, in particular by means of snap connections. The outer housing is thus essentially formed from a plurality of individual screens, which are implemented, for example, in the shape of tiles and are thus easy to replace. In this way, it is also possible to form the outer housing of a very large screw press with a screen body or screen formed, for example, in a 3D printing process.

[0041] Since the screen implemented according to the present invention can easily be implemented with very different geometries, it can also be provided that screens with different hole geometries and / or different opening surfaces are used over the length of the screw press. As a result, the geometry of the screen can be altered, for example, to adapt to the prevailing operating conditions at a corresponding location in the screw press, in particular to adapt to the dry content of the transport material being dried at the corresponding location, such that a more efficient process can be achieved.

[0042] In principle, the screen can be arranged in the outer housing in very different ways. It is advantageous if the screen is fixed in place in the outer housing by means of fastening means (preferably by means of a threaded connection). The fastening means can be embodied, for example, as fastening guides.

[0043] It has proven effective that the outer housing includes a support structure, in particular a support basket, to which the screen is connected in a form-fitting and / or press-fitting manner, in particular by means of a threaded connection. The screen or screens that achieve the screening effect of the outer housing can then be easily replaced.

[0044] The support structure is usually embodied as a support basket. In order to be able to retrofit an existing screw press in a particularly simple manner with a screen according to the invention, it is preferably provided that the support basket is made of metal. A support basket of this type can then accommodate both a conventionally produced metal sheet screen and a screen implemented according to the invention, so that an existing screw press can be easily equipped with a screen implemented according to the invention.

[0045] It is preferably provided that the screen is connected to the support structure in a form-fitting manner by means of fastening means. The fastening means can be embodied, for example, as fastening guides having a T-shaped cross-section and can be positioned between two screens, so that each screen is connected to the support structure by two fastening guides arranged on the lateral edges of the screen.

[0046] Furthermore, it can be provided that the fastening means are made of the same material as the screen body. It is thus ensured that the fastening means are affected by abrasive wear in the same way as the screen body itself, so that a consistent surface removal occurs, so that even in the case of wear, a substantially uniform surface remains unchanged.

[0047] Generally, the screen consists of a single part, which is composed of a body formed by a sintering process and / or an additive manufacturing process (in particular a 3D printing process). Features of the screen for fastening (such as folding seams, grooves, protrusions, etc.) can thus be easily formed, for example, during the additive manufacturing process. Description of the Drawings

[0048] Further features, advantages and effects of the invention result from the exemplary embodiments described below. In the drawings to which reference is hereby made:

[0049] Figure 1 shows a screw press;

[0050] Figure 2 shows a part of the outer housing;

[0051] Figure 3 and Figure 4 shows the screen;

[0052] Figure 5 Showing the screen together with the support basket and the fastening device;

[0053] Figure 6 Showing a sectional view of the screen;

[0054] Figures 7 to 9 Showing Figure 6 a detailed view of. Detailed implementation

[0055] Figure 1 The screw press 10 according to the present invention is shown in a partial cross-sectional view. The screw press 10 is designed to separate liquid from a transport material, in particular from a slurry, and includes a worm shaft 11 which is arranged in a fixed housing 13 such that it can be rotated about a longitudinal axis 15 by means of a drive, wherein a screw conveyor 12 is arranged on the worm shaft 11 such that a transport channel for the transport material being conveyed is formed between the worm shaft 11, the housing 13 and the screw conveyor 12. In the rotation of the worm shaft 11 about the longitudinal axis 15, the transport material is thus also conveyed along the longitudinal axis 15 in the transport channel, wherein pressure is applied to the transport material in order to separate the liquid located in the transport material. The separated liquid is thus transported out of the interior of the screw press 10 through the housing 13, wherein the housing 13 serves as a screen.

[0056] In the described exemplary embodiment, the housing 13 of the screw press 10 is formed by a housing element 16 which is substantially semi-cylindrical on the inside, wherein one housing element 16 is illustrated in Figure 2 The housing element 16 includes a screen 1 which is fastened to a support basket 14 (which consists of metal in this case), and has openings 18 which are not illustrated in Figure 2 in order to separate solids from liquids during the operation of the screw press 14.

[0057] It can be seen that the individual screen 1 is thus implemented as a tile, that is to say, as a part of the shell surface of a cylinder, and is supported radially outwards on the support basket 14. As a result, an internal pressure of, for example, 1 bar to 10 bar can be applied to the housing 13 during the operation of the screw press 10, which does not cause any significant deformation of the screen 1. The tile-shaped screen 1 is positively connected to the support basket 14 via a fastening device implemented as a fastening guide 19, the fastening guide 19 being implemented with a T-shaped cross-section and being connected to the support basket 14 via a threaded connection.

[0058] The normal operation of the screw press 10 fundamentally depends on ensuring a defined friction between the conveying material and the screen surface 5, because once the friction drops below a defined minimum value, the conveying material is not conveyed along the longitudinal axis 15, but instead rotates about the axis of rotation together with the worm shaft 11.

[0059] According to the invention, the screen body (i.e., the part of the screen 1 that includes the screen surface 5 with openings 18) is formed by a sintering process and / or an additive manufacturing process, such that even if a surface or a part of the screen surface 5 is removed (e.g., by abrasive wear), a screen surface 5 with a predetermined minimum roughness is still produced when the conveying material slides over the screen surface 5, so that a completely smooth surface of the screen body cannot be achieved, and with such a surface, the normal operation will no longer be ensured.

[0060] In an exemplary embodiment, the screen 1 is formed entirely of the screen body, although of course the following embodiments are also conceivable, in which the screen body formed by a corresponding method is, for example, detachably arranged in a frame of the screen 1 formed by a plurality of parts, and the frame can also be composed of a material different from that of the screen body.

[0061] In this case, the fastening device implemented as a fastening guide rail 19 with a T-shaped cross-section is formed of a material corresponding to the screen body and can likewise be produced by a 3D printing process, such that the wear of the fastening guide rail 19 corresponds to the wear of the screen body, and even in the case of wear or after a long-term operation of the screw press 10, an internally substantially cylindrical and uniform surface of the housing 13 is ensured.

[0062] Figures 3 to 9 The corresponding screen 1 is shown in a detailed view, where Figure 3 The screen 1 is shown in an isometric view, Figure 4 A top view of the screen 1 is shown, Figure 5 Shown together with a part of the support basket frame 14 and the fastening guide rail 19, Figure 3 and Figure 4 a side view of the screen 1 shown in Figure 6 and a cross-section along line VI-VI in Figure 4 is shown. Figure 7 Shown Figure 6 detailed view VII of Figure 8 Shown Figure 6 detailed view VIII of Figure 9 Shown Figure 6 detailed view IX of

[0063] It can be seen that the sieve 1 is substantially implemented in the shape of a cylindrical housing, and on the inner sieve surface 5 of the sieve 1, a plurality of openings 18 extending in the radial direction through the sieve 1 are provided. In Figure 6 and Figure 7 it can be seen that the cross-section of the opening 18 increases from the inside to the outside, or increases as the distance from the sieve surface 5 increases. Therefore, it is easy to prevent the opening 18 from being blocked, and at the same time, it is ensured that only solids with a diameter 17 smaller than the minimum diameter 17 of the opening 18 are transported out of the inside. In the illustrated embodiment, the diameter 17 can be, for example, 1.5 mm. The opening 18 can also, as particularly visible in Figure 7 be implemented with an opening angle α, and the opening angle α can be, for example, 10° to 30°.

[0064] In order to be able to connect the individual sieves 1 in the direction of the longitudinal axis 15 of the screw press 10 in a simple manner, grooves 8 are provided on the first side surface 6 of the sieve 1 or the sieve body, and protrusions 9 corresponding to the grooves 8 are provided on the second side surface 7 opposite to the first side surface 6, as can be seen in Figure 6 , Figure 7 and Figure 8 The first side surface 6 and the second side surface 7, as well as the grooves 8 and the protrusions 9, extend in the circumferential direction in the sieve 1 described in the exemplary embodiment.

[0065] The protrusion 9 is illustrated in detail in Figure 8 It can be seen that the protrusion 9 includes a dent 2 so that the engagement of the protrusion 9 in the groove 8, which is illustrated in detail in Figure 9 , is possible. In this way, a snap mechanism for the simple connection of multiple sieves 1 along the longitudinal axis 15 is easily achieved.

[0066] The fastening of the sieve 1 in the support basket 14 can occur, as shown in Figure 2 , via two fastening guide rails 19 arranged along the sieve 1. For this purpose, on the lateral edges of the sieve body that extend substantially parallel to the longitudinal axis 15 in the installed state, each folding seam 3 corresponding to the cross-section of the fastening guide rail 19 is implemented so that when, as can be seen in Figure 5 , the fastening guide rail 19 is arranged between two sieves 1, a substantially cylindrical interior of the housing shell 13 is obtained.

[0067] In Figure 5In it, the support basket 14 and the fastening guide rail 19 arranged behind the screen 1 in the screw press 10 are also schematically illustrated. It can be seen that in this case, the fastening guide rail 19, which is implemented with a substantially T-shaped cross-section, is connected to the support basket 14 by means of screws 4 in order to form-fittingly fix the screen 1 in the appropriate position on the support basket 14.

[0068] Alternatively, drill holes can also be provided in the screen 1 in order to directly screw the screen 1 to the support basket 14.

[0069] In an exemplary embodiment, the screen body and the screen 1 are formed in one piece with plastic in a 3D printing process, wherein the openings 18 are also formed during the 3D printing process. A material that exhibits a constant roughness even in the presence of wear on the screen surface 5 is thus obtained, so that the normal operation of the screw press 10 is ensured even in the case of wear of the screen body.

[0070] Different materials can also be used to form the screen 1 in order to achieve higher rigidity and lower porosity, for example, at an increasing distance from the screen surface 5, so that high rigidity is achieved, although the tribological properties are beneficial. Additionally, fibers can also be incorporated into the screen 1 or formed in the screen body in order to obtain beneficial mechanical properties.

[0071] Therefore, with the screen 1 implemented according to the invention, operation of the screw press 10 without frictional damage for a particularly long period of time is possible, especially since wear on the screen body also does not cause a reduction in the friction between the conveyed material and the screen 1. Furthermore, screens 1 with very different geometries can be easily formed in order to be able to provide, for example, different screens 1 with different hole geometries and / or different opening surfaces depending on the conveyed material being dried and the position on the screw press for various operating conditions that may occur. As a result, the corresponding drying process can be achieved with a specific efficiency.

Claims

1. A method for producing a screen body of a screen (1) to be used in a screw press (10), the screen body including one or more openings (18) on a screen surface (5), wherein the screen body is formed by an additive manufacturing process, characterized in that The screen body is at least partially formed of a plastic that is dimensionally stable under a pressure load of 1.5 N / mm 2 at a temperature of at least 45 °C.

2. The method according to claim 1, wherein When the screen body is being formed, fibers are incorporated into and / or formed within the screen body.

3. The method according to claim 1 or 2, characterized in that The screen body is formed of different materials in terms of thickness.

4. The method according to claim 3, wherein The screen body is formed of a first material and a second material, the first material constituting the screen surface (5), and the second material constituting the region of the screen body spaced apart from the screen surface (5), wherein the second material is more rigid than the first material.

5. The method according to claim 1, wherein The screen body is at least partially formed of a plastic that is dimensionally stable under a temperature of at least 90 °C and a pressure load of 1.5 N / mm 2 2.

6. The method according to claim 1 or 5, characterized in that The one or more openings (18) are formed during the additive manufacturing process.

7. The method according to claim 1, wherein The screen body is formed by a 3D printing process.

8. A screen (1) for a screw press (10), the screen (1) having a screen body including one or more openings (18) on a screen surface (5), wherein the screen body is composed of a plastic formed in an additive manufacturing process, characterized in that The screen body is at least partially formed from a plastic that is dimensionally stable at a temperature of at least 45 °C and a pressure load of 1.5 N / mm 2 and the screen (1) is produced by the method according to any one of claims 1 to 7.

9. The screen (1) according to claim 8, characterized in that The screen body has a substantially constant defined porosity up to a defined depth.

10. The screen (1) according to claim 8 or 9, characterized in that The screen (1) is implemented as part of a substantially rotationally symmetric body such that a plurality of identical screens (1) can be combined to form a substantially rotationally symmetric body.

11. The screen (1) according to claim 8, characterized in that On at least one lateral edge, recesses are provided so that the screen (1) is form-fittingly fixed in place.

12. The screen (1) according to claim 8, characterized in that On a first side surface (6) arranged substantially perpendicular to the screen surface (5), grooves (8) are provided.

13. The screen (1) according to claim 12, characterized in that On a second side surface (7) arranged substantially parallel to the first side surface (6), protrusions (9) corresponding to the grooves (8) are arranged so that two correspondingly implemented screens (1) can be form-fittingly and / or press-fittingly connected via the protrusions (9) and the grooves (8) through the first side surface (6) and the second side surface (7).

14. The screen (1) according to claim 8, characterized in that The screen body consists of plastic formed in a 3D printing process.

15. The screen (1) according to claim 9, characterized in that The screen body has a substantially constant defined porosity up to a depth of at least 1 mm.

16. The screen (1) according to claim 10, characterized in that The screen (1) is implemented as part of the shell of a cylinder or a cone.

17. The screen (1) according to claim 11, characterized in that The recesses are fold seams (3) or chamfers.

18. The screen (1) according to claim 11, characterized in that The screen (1) is form-fittingly fixed in place in a direction perpendicular to the screen surface (5).

19. A screw press (10) for separating a liquid from a transport material, the screw press (10) having a worm shaft (11) together with a screw conveyor (12) and a housing shell (13) surrounding the conveyor, the screw conveyor (12) being arranged helically on the worm shaft (11), wherein a transport channel for the transport material being conveyed is implemented between the worm shaft (11) and the housing shell (13), wherein the housing shell (13) comprises at least one screen (1) such that the liquid separated from the transport material can be conveyed through the housing shell (13), characterized in that The screen (1) is implemented according to any one of claims 8 to 18.

20. The screw press (10) according to claim 19, characterized in that The screen (1) extends only over a part of the circumference of the outer shell (13), the part being implemented in a substantially cylindrical or frustoconical shape.

21. The screw press (10) according to claim 19 or 20, characterized in that A plurality of identical screens (1) are provided, and the plurality of screens (1) are form-fittingly and / or press-fittingly connected to each other.

22. The screw press (10) according to claim 19, characterized in that The screen (1) is fixed in place in the outer shell (13) by using fastening means.

23. The screw press (10) according to claim 19, characterized in that The outer shell (13) includes a support structure, and the screen (1) is form-fittingly and / or press-fittingly connected to the support structure.

24. The screw press (10) according to claim 22, characterized in that The fastening means consists of the same material as the screen body.

25. The screw press (10) according to claim 21, characterized in that The plurality of screens (1) are form-fittingly and / or press-fittingly connected to each other by means of snap connections.

26. The screw press (10) according to claim 22, characterized in that The screen (1) is fixed in place in the outer shell (13) by means of a threaded connection.

27. The screw press (10) according to claim 23, characterized in that The outer shell (13) includes a support basket (14).

28. The screw press (10) according to claim 23, characterized in that The screen (1) is form-fittingly and / or press-fittingly connected to the support structure by means of a threaded connection.

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