CN110267784B

CN110267784B - Method and extrusion device for producing a substrate from a ceramic mass, and substrate

Info

Publication number: CN110267784B
Application number: CN201880010889.8A
Authority: CN
Inventors: 维尔纳·布格尔
Original assignee: Lapp Insulators GmbH
Current assignee: LIW Composite GmbH
Priority date: 2017-02-09
Filing date: 2018-02-08
Publication date: 2022-08-02
Anticipated expiration: 2038-02-08
Also published as: EP3580029A1; DE102017202043A1; JP2020506831A; DE102017202043B4; CN110267784A; WO2018146224A1; JP6937378B2

Abstract

A method and an extrusion device (2) for producing a base body (10) having a predetermined first diameter (D1) from a ceramic mass are described. The extrusion device (2) is provided with a mouthpiece (8) having a delivery diameter (D2) on the end side, which delivery diameter is smaller than the first diameter (D1). The ceramic mass is pressed against a movable substrate table (14), wherein a counter pressure is generated via the substrate table (14) on the ceramic mass leaving the mouthpiece (8) so that the ceramic mass widens to a first diameter (D1) to form the substrate (10).

Description

Method and extrusion device for producing a substrate from a ceramic mass, and substrate

Technical Field

The invention relates to a method and an extrusion device for producing a substrate from a ceramic mass. The invention also relates to a substrate.

Background

The insulation of high-voltage lines and high-voltage installations is an essential component of high-voltage technology. In transformer and distribution equipment, insulators are also subject to high technical requirements. Ceramic insulators are generally used as insulators.

For the production of such insulators, ceramic masses are used, which are shaped into a so-called matrix (Hubel) by an extrusion process. Subsequently, the desired geometry of the base body (also referred to as blank) for the respective application requirements is given by means of a cutting process. After drying, a glaze is also usually applied, for example in a bath. Subsequently, the processed blank is fired and an insulator is obtained. The material density of this matrix plays an important role in the quality of the insulator at a later date. In order to produce high material densities, use is made in particular of so-called vacuum extrusion apparatuses which are usually oriented vertically.

In high and ultra high voltage installations large-bore insulators are used, which have a diameter in the range of 200mm to 500mm or up to 600mm and which have a length in the range of meters.

Such a vertical vacuum extrusion device is known from DE 000001258775B. The apparatus has a master cylinder, an extrusion head, and a cylindrical mouthpiece. The process and the main function of the cylindrical mouthpiece are known from "technology der Keramik (ceramic technology)" volume 2, pages 165-166, published by VEB press. Here, the ceramic mass is conveyed to a vertically arranged extruder and evacuated. The ceramic mass is then compressed by means of an extrusion screw and an extrusion head and exits the extruder through a nozzle adjacent to the extrusion head. In order to prevent the ceramic material leaving the mouthpiece from tearing, there is a so-called substrate table below the mouthpiece, which receives the ceramic material to form the substrate and moves in a vertical direction away from the mouthpiece in synchronism with the delivery speed of the substrate.

The production of substrates with high material compaction, in particular with large calibers, is only possible to a limited extent using conventional methods.

Disclosure of Invention

In view of the above, the object of the invention is to provide a method for producing a substrate, in particular a large-diameter substrate, and an extrusion device, by means of which a large-diameter substrate having a high density can be produced. Furthermore, the object of the invention is to provide a substrate having a high density.

This object is achieved according to the invention by the method according to the invention for producing a base body, in particular a large-diameter base body. The substrate is made of a ceramic material and has a first diameter. The first diameter describes the maximum outer diameter of the base body and thus defines the base body diameter.

In this method, ceramic material is extruded through a mouthpiece and received by a substrate table that applies a counter pressure to the material exiting the mouthpiece. Of particular interest is a mouthpiece which widens in the vertical direction, starting from a minimum inner diameter, in particular conically, to a delivery diameter, wherein the inner diameter is smaller than the base body diameter. The counterpressure through the substrate table ensures that the mouthpiece is filled uniformly with material at the end in the region of the widened delivery diameter.

Tests have shown that particularly good degrees of compression are thereby achieved in a surprising manner. The degree of compression is decisively determined by the smallest inner diameter of the mouthpiece, since the material is subjected to the highest degree of compression here. This degree of compression is subsequently maintained despite the widening of the mouthpiece. Thus, plastic materials have a memory in terms of degree of compression. No or only a small degree of resilient deformation or relaxation due to the conical widening occurs. This indicates a significant reduction in the rate of drying during drying compared to conventionally fabricated substrates. In conventionally made matrices, the shrinkage during drying is about 3% (by volume). In the matrix made using the novel process described herein, the dry shrinkage during this drying was reduced to about 1%. Due to the counterpressure, at the same time the desired base body diameter (increased compared to the inner diameter) is also achieved.

The advantage of this design is believed to be the ease of manufacturing large diameter substrates with high material density. This results in a higher mechanical (bending) strength in the finished insulator after firing. Tests prove that the strength can be improved by about 20 to 25 percent (compared with a conventionally manufactured matrix/insulator). This in turn allows for higher strength to be considered in designing the insulator and using a smaller or thinner insulator with less material with the same strength value. A significant material saving is thereby obtained. Overall, the new method improves the quality of the substrate and future insulators. In addition, the reject rate in the production of the base body is thereby also reduced. In addition, this also allows the production of substrates with very large diameters, which hitherto could not be produced (with sufficient strength) using conventional methods.

In the method, a plurality of mouthpiece variants having different (minimum) inner diameters and delivery diameters can suitably be used. In all variants, the minimum inner diameter has a value preferably in the range from 350mm to 500mm, in particular in the range between 430mm and 460 mm. The advantage of this design is consistent and easy assembly of the variant of the mouthpiece.

Preferably, the mouthpiece widens in a vertical direction from an inner diameter to an exit diameter with a taper angle. The cone angle of the mouthpiece is preferably in the range between 2 ° and 5 °, in particular in the range 3 ° to 4 °. A cone angle in this angle range has proved to be particularly suitable for producing especially large-caliber substrates with a diameter of more than 450mm, which substrates have a high strength.

In a suitable embodiment, the mouthpiece has a conical inlet section at the upper end. Thus, the mouthpiece has an increased diameter at its upper end compared to the minimum inner diameter. This serves, in particular when the inner diameter is small, to widen the mouthpiece from the flange side toward the extrusion head to a defined size in order to ensure a uniform flange for fastening for different mouthpieces. By means of the conical inlet section, the ceramic mass is also subjected to an additional compression in the region of the inlet section.

Alternatively, no inlet section is provided, but the mouthpiece widens continuously conically from its upper end to its lower end. Thus, the mouthpiece already has this inner diameter at its upper end.

For producing large-diameter substrates, the first diameter (substrate diameter) here has a value preferably in the range from 400mm to 650mm, in particular in the range from 430mm to 620 mm.

The widening of the mouthpiece is used in particular to set the desired diameter of the base body. The delivery diameter has a value preferably in the range between 270mm and 600mm, in particular in the range 400mm to 570 mm.

In a preferred embodiment, the ceramic mass leaving the mouthpiece is widened to the desired first diameter by the counter pressure. The delivery diameter of the mouthpiece is therefore smaller than the (largest) outer diameter of the base body. The base body itself is thus conical and tapers from its first diameter (the largest diameter of the base body) upwards to a delivery diameter.

In a preferred embodiment, the first diameter is 5% to 15%, in particular 7% to 12%, greater than the delivery diameter, i.e. the outer diameter of the base body is greater than the delivery diameter of the mouthpiece.

The length of the substrate is typically in the range of 2m to 3.5 m. Typically, the length is related to, preferably at least approximately proportional to, the diameter of the substrate. Thus, a short substrate (e.g. 2m) has a small substrate diameter of e.g. 400 to 450mm, while a long substrate (e.g. 3.5m) has a large diameter of e.g. 580 to 630 mm.

The base body preferably widens conically at an angle, which is preferably in the range from 4 ° to 7 °, and in particular in the range from 5 ° to 6 °.

The degree of compression is defined by the area ratio formed by the first cross-sectional area and the second cross-sectional area, which is determined by the (largest) outer diameter of the basic body. The second cross-sectional area is here the cross-sectional area of the discharge side of the extruder in which the extrusion screw is arranged, which typically ends at the extruder end. The extruder is followed by a mouthpiece, wherein typically also an extrusion head is arranged between the mouthpiece and the extruder. The degree of compression is preferably in the range between 3 and 5. The degree of compression is "set", for example, by appropriate selection of a mouthpiece with a defined inner diameter and/or by setting an appropriate counter pressure. As the first diameter (base diameter) increases, the degree of compression generally decreases.

In order to achieve high material strength when constructing a base body having a first diameter in the range between 400mm and 500mm, the degree of compression is preferably set to a value of 3.5 to 5.

The degree of compression of the matrix having a first diameter in the range 500mm to 650mm advantageously has a value in the range 3 to 4. The selected compressibility value has the advantage that the rejection rate of the substrate is reduced compared to conventional substrates made with cylindrical mouthpieces and having a lower compressibility. The scrap rate is reduced by one third to one fourth compared to such conventional substrates.

Advantageously, the value of the counter pressure of the substrate table is greater than 0.5N/mm ² And especially greater than 1N/mm ² . Advantageously, this value is at most 3.5N/mm ² Or at most 2.5N/mm ² . In particular, the counter pressure is 1.5N/mm ² And 2.5N/mm ² Within the range of (a).

This achieves, on the one hand, a deformation of the material in the conical mouthpiece and, on the other hand, an ancillary compression of the cross-sectional texture in the base body. The cross-sectional texture is formed as a result of an extrusion screw operating in an extruder. The extrusion screw produces a spiral profile corresponding to the screw pitch. Thereby forming a nested bundle with an extremely smooth surface. These nested bundles are squeezed in the squeezing head and the mouthpiece so that they establish a tight connection, as a result of which a compact base body is obtained. Thus, the denser the compression. Thus, the ratio of the diameter of the extrusion screw (which defines the second cross-sectional area) to the minimum internal diameter of the mouthpiece is particularly important.

By this method, a solid core substrate with a large diameter is preferably manufactured, from which a solid post insulator is usually manufactured. Compared to hollow insulators, this type of insulator provides an improved breakdown strength in the high and ultra high voltage range. In principle, the method described here can also be used for the production of hollow insulators.

The object of the invention is also achieved according to the invention by an extrusion device for producing a substrate according to the invention. The substrate is formed from a ceramic material at a predetermined first diameter. The extrusion device has an extruder and a mouthpiece on the end side. Typically, an extrusion head, typically a stepped extrusion head, is also arranged between the extruder and the mouthpiece. The mouthpiece extends in a vertical direction and has a delivery diameter at an end side. The extrusion device also has a substrate table that can be moved in and against the vertical direction and a control device. Preferably, the extruder is vertically oriented and configured as a vacuum extruder. In this case, an evacuation chamber is usually arranged inside the extruder in order to evacuate the ceramic mass and thus to produce a complete throughput of material and to remove quality-reducing inclusions inside the ceramic mass.

The vertical design offers the advantage that, in addition to the forces generated by the screw and the resulting friction, the ceramic mass moves due to its own weight in the direction of the mouthpiece and thus achieves mechanical stress relief of the extrusion screw. In view of this, this design offers advantages in terms of maintenance and lifetime of the extruder.

The extrusion head is designed, for example, in such a way that it is realized as a stepped extrusion head. During the manufacturing process, the ceramic mass is compressed in the extrusion head into a matrix, after which it is fed out via a mouthpiece attached to the extrusion head on the end side.

Of particular interest is a mouthpiece that widens conically from a (smallest) inner diameter to a delivery diameter. The inner diameter and preferably the delivery diameter is smaller than the first diameter (the maximum substrate diameter).

This object is achieved according to the invention by a base body produced in particular by the above-described method. The base body widens conically from the upper end to the lower end at an angle. This conical geometry is created by the back pressure of the substrate table on the ceramic mass exiting the mouthpiece when constructing the substrate.

The angle is advantageously in the range between 4 ° and 7 °, in particular in the range from 5 ° to 6 °.

The advantages and preferred embodiments listed in relation to the method can be applied analogously to the extrusion device and/or the base body and vice versa.

Drawings

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are shown, in part, in a greatly simplified illustration, in which,

FIG. 1 shows a schematic configuration of an extrusion apparatus for producing substrates with a movable substrate table and a control device;

fig. 2A to B show longitudinal sectional views of two design variants of mouthpieces;

FIG. 3 shows a longitudinal section through a section of a vacuum extrusion apparatus; and

fig. 4 shows a longitudinal section through the base body.

In the figures, parts having the same function are shown with the same reference numerals.

Detailed Description

Fig. 1 shows a schematic configuration of an extrusion device 2 for producing a base body 10 of a predetermined first diameter D1 from a ceramic mass. The first diameter D1 defines a maximum outer diameter of the substrate 10, which is also referred to herein as the substrate diameter. The extrusion device 2 shown in fig. 1 is realized in a vertical configuration and extends in a vertical direction 12. The extrusion apparatus 2 is used to make a substrate 10, especially of large caliber. The vertical structure can fully utilize the gravity acting on the ceramic material. Because the output direction corresponds to the gravity direction, the ceramic material conveying device is favorable for conveying the ceramic material.

The extrusion device 2 has an extruder 4, a extrusion head 6 coupled to the extruder 4 on the end side, and a mouthpiece 8. The mouthpiece 8 adjoins the extrusion head 6 as seen in the vertical direction 12 and has a discharge diameter D2 on the end side. Here, the delivery diameter D2 is smaller than the first diameter D1.

The extruder 4 is preferably configured as a vacuum extruder. Through this design can realize exhausting to ceramic material.

The extrusion head 6 is preferably designed in such a way that it has a plurality of extrusion stages. So-called stepped extrusion heads enable a high degree of compression of the ceramic mass.

The mouthpiece 8 is preferably attached to the extrusion head 6 on the end side by means of a screw connection and is used to construct the base body 10 as a supplement to the extrusion head 6. By screwing, a cost-effective replacement of the mouthpiece 8 is ensured.

Furthermore, the mouthpiece 8 is conically designed. Thus, the mouthpiece 8 has a (smallest) inner diameter D3, from which it tapers to a delivery diameter at a taper angle α. The mouthpiece 8 typically has a length L in the vertical direction 12 in the range between 500mm and 1200mm, in particular in the range 700mm to 900 mm.

Below the mouthpiece 8, viewed in the vertical direction 12 and thus in the production direction, a substrate table 14 is constructed which can be moved along and against the vertical direction 12. The substrate table and the entire extrusion device 2 are controlled by a control device 16. The substrate table 14 is designed in such a way that, during operation, it exerts a counter pressure on the ceramic mass leaving the mouthpiece 8.

By means of the counterpressure of the substrate table 14, pressure is exerted on the ceramic mass in the mouthpiece 8, so that the mouthpiece (despite the conical widening) is reliably filled. The decisive factor here is the high degree of compression which the material retains despite its subsequent widening due to the smaller internal diameter D3 compared to the delivery diameter D2.

In addition, the ceramic mass leaving the mouthpiece 8 is preferably further widened by the counterpressure to a first diameter D1 to form the base body 10. This forms the base 10 which is tapered and widened.

For this purpose, the control unit 16 and the substrate table 14 are designed in such a way that, during operation, they set the counterpressure to at least 0.5N/mm ² A value of, in particular, more than 1N/mm ² Or more than 1.5N/mm ² The value of (c).

Suitably, the counter pressure preferably has a value of 2.5N/mm ² The value of (c). In particular, this value is in the range of 1.5N/mm ² To 2.5N/mm ² Within the range. The control unit is connected to the substrate table 14, for example, by way of a control line. The control unit 16 is designed overall in such a way that it regulates the entire extrusion process in the desired manner. The manipulated variable for actuating the substrate table is preferably a reaction force.

A longitudinal cross-sectional view of a variation of mouthpiece 8 is shown in fig. 2A and 2B. The mouthpiece 8 preferably has an upper end 8a, at which a flange for fastening to the extrusion head 6 is formed. The mouthpiece 8 also has a lower end 8b at which a delivery diameter D2 is defined.

Each mouthpiece 8 has a minimum inner diameter D3, respectively. The mouthpiece widens from this minimum inner diameter, in particular conically, with a cone angle α to a delivery diameter D2. Preferably, a continuous, uniform conical widening is provided. In principle, however, it is also possible to provide a partial region that is not conical, for example a cylindrical end region at the lower end 8 b.

Preferably, the cone angle α is in the range between 2 ° and 5 °, in particular in the range from 3 ° to 4 °. In combination with the compression caused by the substrate table 14, by means of this mouthpiece topology, a compression of the ceramic mass of preferably 50% higher than in the case of the prior art substrates can be achieved when the substrate 10 is constructed.

In the variant according to fig. 2A, the mouthpiece 8 additionally has a conical inlet section 18 at the upper end 8a, so that the mouthpiece tapers first from an entry diameter D4 to an inner diameter D3. The conical inlet section 18 extends over only a small portion of the length L1 of the mouthpiece 8, for example up to 5% or 10% of the length L1. Thereby, compression is achieved in the region of the inlet section 18. In particular, the inlet section 18 serves to bring the flanged upper end 8a to a defined size, so as to constitute a plurality of mouthpieces 8 having different internal diameters D3 and delivery diameters D2, with flanges of the same size. Thereby, different mouthpieces 8 can be coupled with the same extrusion head 6.

Accordingly, in the embodiment of fig. 2B, the mouthpiece 8 widens continuously from the upper end 8a to the lower end 8B. Thus, in this variant, the inner diameter D3 is directly identified by the upper end 8 a.

According to fig. 3, the extruder 4 has a known vertical design. The extruder 4 shown in longitudinal section has a first extruder part 22, a second extruder part 24, an extrusion screw 20, an extrusion head 6 and a mouthpiece 8.

The second extruder portion 24 adjoins the first extruder portion 22 on the end side, as seen in the vertical direction 12. The first extruder portion 22 serves to pre-compress the ceramic mass, which is further compressed by the extrusion screw 20 in a further process. Furthermore, the second extruder part 24 has longitudinal slats on the inner circumferential side. The longitudinal slats support the conveyance of the ceramic mass inside the second extruder portion 24.

The extruder 4 is designed as a vacuum extruder as a whole and has an evacuation chamber (not shown in fig. 3) for this purpose. By means of the evacuation chamber, all inclusions in the ceramic mass are evacuated by the exhaust gas and a uniform throughput is achieved.

The transfer of the ceramic material is achieved by means of the extrusion screw 20. Which in operation entrains and compresses the ceramic mass inside the extruder 4 by rotating about the axis of rotation 21. Due to the vertical design of the extruder 4, the extrusion screw 20 is mechanically relieved of load by the self-movement of the ceramic mass due to gravity. The extrusion screw 20 has a screw end piece at its end, which is connected to the central shaft via a meshing (face-tooth meshing; Hirth-Verzahnung).

The extrusion head 6 adjoining the second extruder part 24 on the end side serves for compressing the ceramic mass. The area at the transition on the end side between the second extruder part 24 and the extrusion head 6 defines a second cross-sectional area F2.

The extrusion head 6 shown in fig. 3 is designed as a stepped extrusion head, which has longitudinal webs in the interior, likewise on the circumferential side.

The conical mouthpiece 8 adjoins the extrusion head 6 on the end side. The mouthpiece has a delivery diameter D2 at the lower end 8b of the mouthpiece 8 in the vertical direction 12.

In fig. 3, a central guide rod 26 is also arranged in the mouthpiece 8, on which a bell-shaped widening is fastened on the end side. The widened portion serves to form a central cavity. The mouthpiece 8 is thus arranged to constitute a hollow base.

Rather, such guide rods 26 and the bell-shaped widening are preferably eliminated and the mouthpiece 8 is configured for constituting a solid base body 10, i.e. without a cavity.

The base body 10 shown in fig. 4 is constructed as a solid base body of a large caliber. Solid matrices or solid matrices of this geometry are preferred for high and ultra-high voltage technology, since so-called solid post insulators are made therefrom. This type of insulator is more advantageous in terms of breakdown strength than a hollow insulator, and is therefore preferably used in high voltage and ultra high voltage ranges.

The base body 10 preferably has a conical course at an angle β from the upper end to the lower end. Advantageously, the angle is in the range between 4 ° and 7 °. The base body 10 preferably has a first diameter D1 at a lower end through which a first cross-sectional area F1 is defined. The first diameter D1 corresponds to the maximum outer diameter of the base.

The base body 10 has a diameter at the upper end which corresponds to the discharge diameter D2. The base body 10 has a length L2 from an upper end to a lower end in the vertical direction 12. The length is typically in the range of 2m to 3.5 m.

In addition to the extruder 4 having the second cross-sectional area F2 on the end side, the area ratio between the first cross-sectional area F1 and the second cross-sectional area F2 also defines the degree of compression, which is preferably set to a value between 3 and 5.

List of reference numerals

2 extrusion device

4 extruder

6 extrusion head

8 mouth piece

8a upper end of the mouthpiece

8b lower end of mouthpiece

10 base body

12 in the vertical direction

14 base body table

16 control device

18 conical inlet section

20 extrusion screw

21 axis of rotation

22 first extruder part

24 second extruder section

26 guide bar

Cone angle of alpha mouthpiece

Angle of beta base body with conical widening

D1 first diameter

D2 discharge diameter

D3 inner diameter

D4 entry diameter

F1 first cross-sectional area

F2 second cross-sectional area

Length of L1 mouthpiece

Length of L2 base

Claims

1. Method for producing a base body (10) having a predetermined first diameter (D1) from a ceramic mass by means of an extrusion device (2), the extrusion device (2) comprising a mouthpiece (8) having an inner diameter (D3),

it is characterized in that the preparation method is characterized in that,

the mouthpiece (8) widens in the vertical direction (12) starting from the inner diameter (D3) to a discharge diameter (D2),

the inner diameter (D3) being smaller than the first diameter (D1),

pressing the ceramic mass in a vertical direction (12) through the mouthpiece (8) towards a substrate table (14),

-generating a counter pressure on the ceramic mass leaving the mouthpiece (8) via the substrate table (14),

the delivery diameter (D2) is smaller than the first diameter (D1) such that the ceramic mass exiting the mouthpiece (8) is widened to the first diameter (D1) by the counter pressure exerted by the substrate table (14) to constitute the substrate (10).

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the mouthpiece (8) widens conically with a cone angle (alpha) in the range between 2 DEG and 5 deg.

3. The method of any one of claims 1-2,

it is characterized in that the preparation method is characterized in that,

the mouthpiece (8) has a conical inlet section (18) at the upper end (8 a).

4. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the first diameter (D1) is in a range between 300mm and 650 mm.

5. The method of claim 1, 2 or 4,

it is characterized in that the preparation method is characterized in that,

the delivery diameter (D2) is in the range between 270mm and 600 mm.

6. The method of claim 1, 2 or 4,

it is characterized in that the preparation method is characterized in that,

the first diameter (D1) is 5% to 15% greater than the discharge diameter (D2).

7. The method of claim 1, 2 or 4,

it is characterized in that the preparation method is characterized in that,

a first cross-sectional area (F1) is defined by the first diameter (D1), and the extrusion apparatus (2) has an extruder (4), the extruder (4) has a second cross-sectional area (F2) on the end side, and the area ratio between the first cross-sectional area (F1) and the second cross-sectional area (F2) defines a degree of compression, wherein the degree of compression in operation yields a value in the range of 3 to 5.

8. The method of claim 7, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

in operation, for a substrate (10) having a first diameter (D1) in the range of 400mm to 500mm, a degree of compression in the range of 3.5 to 5 is produced.

9. The method of claim 7, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

in operation, for a substrate (10) having a first diameter (D1) in the range of 500mm to 650mm, a compressibility value in the range of 3 to 4 is produced.

10. The method of claim 1, 2 or 4,

it is characterized in that the preparation method is characterized in that,

greater than 0.5N/mm applied by the substrate table (14) ² And at most 3.5N/mm ² Or at most 2.5N/mm ² 。

11. The method of claim 1, 2 or 4,

it is characterized in that the preparation method is characterized in that,

the base body (10) is designed as a solid base body.

12. Extrusion apparatus (2) for producing a substrate (10) having a predetermined first diameter (D1) from a ceramic mass, comprising:

-an extruder (4),

-a mouthpiece (8) extending in a vertical direction (12) and having an inner diameter (D3),

a substrate table (14) which is movable along and against a vertical direction (12),

-a control device (16),

it is characterized in that the preparation method is characterized in that,

the substrate table (14) is designed in such a way that, during operation, it exerts a counter pressure on the ceramic mass leaving the mouthpiece (8),

13. A substrate (10) made by the method according to any one of claims 1 to 11,

it is characterized in that the preparation method is characterized in that,

the base body widens conically from an upper end to a lower end at an angle (β).

14. The substrate of claim 13, wherein the substrate is a plastic substrate,

it is characterized in that the preparation method is characterized in that,

the angle (β) is in the range of 4 ° to 7 °.