DE102019200651A1 - Sound generating sheet for wind instruments made of fiber composite material and process for their production - Google Patents

Abstract

The invention relates to a sound-generating sheet for musical instruments made of a fiber composite material and a method for producing sound-generating sheets made of fiber composite material.

Description

The invention relates to a sound-generating or toning sheet for musical instruments, in particular wind instruments made of a fiber composite material, and a method for producing sound-generating sheets made of fiber composite material.

Numerous wind instruments are provided with a sound-generating blade, also known as a tongue or reed. For example, saxophones and clarinets have a single reed. These instruments have a mouthpiece to which the blade is attached in a suitable manner, for example by means of a ligature. There are also double-leaf instruments, such as oboes and bassoons.

In principle, cane wood is used to produce such toner-stimulating leaves. Wood leaves have the disadvantage that their durability is very limited and that their production is very complex. In addition, every wooden sheet has to be imported: every time the wooden sheet is attached to the mouthpiece of the instrument, i.e. not only when an unused new sheet is used for the first time, it takes about half an hour to record. During this time, the playing properties of the wood sheet change due to the absorption of moisture. The natural material is also very sensitive. Cracks often occur, particularly in the area of the blade tip, so that the blade becomes unusable.

It is also known to make clay-producing sheets from plastic. However, the sound to be generated in this way by no means achieves the quality that can be achieved with wooden leaves.

Finally, attempts were made to produce clay-producing sheets from fiber composite material or fiber-reinforced plastic. However, the sound quality that could be achieved was such that numerous wind instrument players were forced to use wooden blades with the disadvantages mentioned.

The WO 93/22761 A1 describes clay-producing sheets made of fiber composite material with a complex fiber structure with fibers of different material properties.

In contrast, it is an object of the invention to provide a sound-generating sheet for wind instruments made of fiber-reinforced plastic, the sound qualities of which are substantially improved, the playing properties of which come very close to that of wooden sheets and which are simple and inexpensive to produce.

The invention solves the technical problem by the subject matter of the independent claims.

The invention solves the technical problem in particular by a sound-generating sheet for a musical instrument, the sound-generating sheet consisting of a fiber composite material, the fiber composite material containing a thermosetting plastic as a matrix and reinforcing fibers, the proportion of reinforcing fibers being at least 2% by weight and at most 30 % By weight.

The sound-generating sheet is preferred for a woodwind instrument, particularly preferably for a clarinet or a saxophone.

The reinforcing fibers can be artificial fibers, for example carbon fibers or glass fibers, or natural fibers, for example cellulose fibers, meadow grass fibers, jute fibers, hemp fibers or flax fibers. The reinforcing fibers can also be mixtures of at least two of these types of fibers.

The reinforcing fibers are preferably carbon fibers or glass fibers. The reinforcing fibers are particularly preferably carbon fibers. The reinforcing fibers can also be mixtures of different fibers, for example carbon fibers and glass fibers.

The reinforcing fibers preferably have a length of at least 0.05 mm and at most 1 mm, particularly preferably of at least 0.1 mm and at most 0.5 mm.

The thermosetting plastic is preferably formed from a polyurethane or an epoxy resin.

The proportion of reinforcing fibers is preferably at least 3% by weight and at most 10% by weight.

The duromer preferably has a density of at least 0.5 g / cm ³ and at most 5 g / cm ³ .

A pickup is preferably cast into the sound-generating sheet.

1. a) Mischen der Matrixkomponenten und der Verstärkungsfasern und erhalten einer Mischung;
2. b) Einfüllen der Mischung in eine Form aus zwei Teilen, wobei die Form so positioniert ist, dass die in der Form sich das formende tonerzeugende Blatt aufrecht vertikal in der Form stehen, wobei bevorzugt die Blattspitze unten und das dicke Blattende oben positioniert ist;
3. c) Entgasen der Mischung durch Anlegen eines Unterdrucks;
4. d) Aushärten lassen der Mischung in der Form.

The clay-producing sheet can preferably be produced by a method comprising the steps:

1. a) mixing the matrix components and the reinforcing fibers and obtaining a mixture;
2. b) pouring the mixture into a two-part mold, the mold being positioned so that the clay-forming sheet forming in the mold is upright vertically in the mold, preferably the tip of the blade is positioned at the bottom and the thick tip of the blade is positioned at the top;
3. c) degassing the mixture by applying a vacuum;
4. d) Allow the mixture to harden in the mold.

Sound-generating sheets according to the invention can be used for wind instruments of various kinds, in particular for saxophones and clarinets. With these instruments, one sheet is placed on the mouthpiece of the instrument; attached that there is an opening almost closed, then the blade in its rear area, i.e. in the area of its shaft with a suitable clamping device, preferably a ligature, is attached to the mouthpiece so that the front end facing the player's mouth, the Leaf tip of the leaf over which the opening in the mouthpiece can swing freely.

Sound-generating sheets according to the invention can also be used in wind instruments which have a double sheet, for example in oboes and bassoons. In these instruments, two sound-producing blades are arranged opposite one another in such a way that when the blades are blown on, an air column starts to vibrate, so that an air column vibrates inside the wind instrument, the length of which can be varied by opening and closing the openings provided in the wind instrument, so that tones of different heights are produced.

Sound-generating blades according to the invention can be used in wind instruments with flaps, counterblows or flaps.

In the context of the present invention, sound-generating sheets are understood to be simple sheets or tongues, for example for clarinets and saxophones, and double sheets, for example for oboes and bassoons.

The sound-generating sheet is preferably a simple sheet. The sound-generating sheet is preferably a sheet for a clarinet or a saxophone.

The leaves according to the invention produce a good sound, are inexpensive to manufacture due to the process used and have a rigidity which is comparable to that of natural wood. This makes it possible in an advantageous manner to adopt the shapes and sizes of leaves from cane wood.

Suitable shapes and sizes, for example the length and thickness of the toner-stimulating sheet, are known to the person skilled in the art and preferably correspond approximately or exactly to the shapes and sizes of sheets from the prior art.

The reinforcing fibers, in particular carbon fibers, are preferably evenly distributed in the fiber composite material and point in different directions, ie do not form any fiber bundles.

The sheet is preferably in one piece and is not constructed from different layers.

It has now surprisingly been found that a sound-generating sheet according to the invention is not only resistant, but also meets the requirements for the sound.

The proportion of reinforcing fibers in the fiber composite material is preferably at least 3% by weight and at most 20% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at least 3% by weight and at most 15% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at least 3% by weight and at most 12% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at least 4% by weight and at most 11% by weight.

The percentages by weight. In the present disclosure, refers to the total weight of the fiber composite composition.

The proportion of reinforcing fibers in the fiber composite material is preferably at least 3.5% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at least 4% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at least 4.5% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at least 5.0% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at most 15% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at most 12% by weight. The proportion of reinforcing fibers in the fiber composite material is preferably at most 10% by weight.

The proportion of reinforcing fibers in the fiber composite material can be, for example, approximately 4% by weight or approximately 7% by weight.

A fiber composite material with at least 4% by weight, in particular at least 5% by weight, and at most 7% by weight is particularly preferred. in particular at most 6% by weight, carbon fibers.

A fiber composite material with at least 4% by weight, in particular at least 5% by weight, and at most 7% by weight, in particular at most 6% by weight, of carbon fibers and with at least 1% by weight, in particular at least 2, is particularly preferred % By weight, and at most 7% by weight, in particular at most 6% by weight, of natural fibers.

A fiber composite material with at least 7% by weight, in particular at least 8% by weight, and at most 11% by weight, in particular at most 10% by weight, of glass fibers is likewise particularly preferred.

A fiber composite material with at least 7% by weight, in particular at least 8% by weight and at most 11% by weight, in particular at most 10% by weight, of glass fibers and with at least 1% by weight, in particular at least, is likewise particularly preferred 2% by weight, and at most 7% by weight, in particular at most 6% by weight, of natural fibers.

The carbon fibers and the glass fibers, in particular in the four particularly preferred embodiments mentioned, are preferably at least 0.1 mm and at most 0.3 mm, in particular approximately 0.2 mm long. The fiber composite material preferably contains, in particular in the four particularly preferred embodiments mentioned, from 0.0% by weight to 15% by weight. Color paste. The fiber composite material particularly preferably contains no color paste or from 0.5% by weight to 10% by weight. Color paste.

The reinforcing fibers preferably have a length of at least 0.05 mm and at most 1 mm.

The reinforcing fibers preferably have a length of at least 0.05 mm. The reinforcing fibers preferably have a length of at least 0.1 mm. The reinforcing fibers preferably have a length of at most 1 mm. The reinforcing fibers preferably have a length of at most 0.5 mm.

The matrix is preferably formed from a thermosetting plastic, ie a thermoset.

Suitable thermosets are known to the person skilled in the art. The duromer is preferably not ebonite.

The duromer is preferably a polyurethane or a polyether or an epoxy resin. The duromer is preferably a polyurethane. Alternatively, the thermoset is an epoxy resin.

The matrix is preferably formed from a polyurethane or a polyether. The matrix can thus be formed in particular from a polyurethane or an epoxy resin.

The duromer, in particular the polyurethane or the epoxy resin, is preferably food-safe.

The person skilled in the art can select suitable thermosets, in particular polyurethanes and polyethers, preferably on the basis of the density of the hardened thermoset.

The cured duromer preferably has a density of at least 0.5 g / cm ³ and at most 5 g / cm ³ . The cured duromer preferably has a density of at least 0.5 g / cm ³ . The cured duromer preferably has a density of at least 0.8 g / cm ³ . The cured duromer preferably has a density of at least 1 g / cm ³ . The cured duromer preferably has a density of approximately 1.1 to 2.2 g / cm ³ . The cured duromer preferably has a density of at most 5 g / cm ³ . The cured duromer preferably has a density of at most 4 g / cm ³ . The cured duromer preferably has a density of at most 3 g / cm ³ . The cured duromer preferably has a density of at most 2.5 g / cm ³ . The preferred densities are preferably measured according to ISO 2781: 88 at 23 ° C.

The cured duromer preferably has a flexural strength of at least 80 MPa and at most 150 MPa. The cured duromer preferably has a flexural strength of at least 110 MPa and at most 120 MPa. The cured duromer preferably has a flexural strength of at least 110 MPa. The cured duromer preferably has a flexural strength of at most 120 MPa. The cured duromer preferably has a flexural strength of approximately 115 to 119 MPa. The cured duromer preferably has a flexural modulus of at least 2000 MPa and at most 3500 MPa. The cured duromer preferably has a flexural modulus of approximately 2800 MPa. The preferred bending strengths are preferably measured according to ISO 178-93 at 23 ° C.

The cured duromer preferably has a tensile strength of at least 50 MPa and at most 110 MPa. The cured duromer preferably has a tensile strength of at least 70 MPa and at most 90 MPa. The cured duromer preferably has a tensile strength of at least 65 MPa. The cured duromer preferably has a tensile strength of at most 85 MPa. The cured thermoset preferably has a tensile strength of approximately 70 to 80 MPa. The preferred tensile strengths are preferably measured according to ISO 527-93 at 23 ° C.

That preferred cured duromer a hardness of at least 55 Shore D1 and at most 115 Shore D1. The cured duromer preferably has a hardness of at least 70 Shore D1 and at most 95 Shore D1. The cured duromer preferably has a hardness of at least 70 Shore D1. The cured duromer preferably has a hardness of at most 100 Shore D1. The cured duromer preferably has a hardness of approximately 75 to 95 Shore D1. Alternatively, the cured duromer has a hardness of at least 55 Shore D1 and at most 75 Shore D1. The preferred hardnesses are preferably measured according to ISO 868-85 at 23 ° C.

It was found that an epoxy resin made from renewable raw materials is also particularly suitable as a duromer, in particular an epoxy resin based on epoxidized vegetable oils, in particular based on linseed oil, as is known, for example, under the name Gripox. The hardener is preferably a mixture of basic anhydrides. The epoxy resin is preferably an epoxy resin based on renewable raw materials. The epoxy resin, in particular also the epoxy resin based on renewable raw materials, is preferably a 2-component epoxy resin.

The fiber composite material preferably contains wood flour. The wood flour is preferably not grenadilla wood flour. The wood flour is preferably selected from the group consisting of cherry wood flour, maple wood flour, in particular bergahom wood flour, or ebony flour.

The fiber composite material can preferably also contain one or more of the following substances: color paste or pigments, finely chopped or ground synthetic fibers such as polyethylene fibers, polyacrylonitrile fibers, glass fibers, finely chopped or ground natural fibers such as jute fibers, cotton fibers, hemp fibers , Flax fibers, cellulose fibers, cellulose such as, for example, chopped or ground meadow grass. In addition, ground metals such as copper and aluminum in various degrees of fineness are suitable as fillers. Other possible fillers are pumice flour, talcum powder, micro-glass bubbles. Thixotropic agents can be added if a higher viscosity is desired, for example to prevent ground copper from sedimenting due to its higher density.

The fiber composite material preferably contains from 0.4% by weight to 20% by weight of color paste, preferably up to 15% by weight, in particular from 0.5% by weight to about 10% by weight of color paste. The fiber composite material preferably contains from 3% by weight to 20% by weight of color paste, in particular from 5% by weight to about 15% by weight of color paste. The color paste is preferably food-safe. The color paste is preferably black.

The fiber composite material preferably contains from 5% by weight to 50% by weight of copper, in particular from 25% by weight to about 45% by weight of copper. The copper is preferably introduced as copper powder.

The copper powder preferably has a degree of fineness or a diameter of at least 5 μm. The copper powder preferably has a degree of fineness or a diameter of at least 25 μm. The copper powder preferably has a degree of fineness or a diameter of at least 45 μm. The copper powder preferably has a degree of fineness or a diameter of at most 350 μm, for example at most 315 μm. The copper powder preferably has a degree of fineness or a diameter of at most 250 μm. The copper powder preferably has a degree of fineness or a diameter of at most 150 μm. The copper powder preferably has a degree of fineness or a diameter of at most 100 μm. The copper powder preferably has a degree of fineness or a diameter of approximately 55 μm to approximately 75 μm.

If coarser powder is used, depending on its own viscosity, thixotropic agents can be added to the resin-hardener mixture in order to achieve a higher viscosity, which prevents the added copper from settling on the bottom of the casting. In the case of very fine copper powder in particular, thixotropic agents can be dispensed with. Suitable thixotropic agents are known to the person skilled in the art. A suitable thixotropic agent is, in particular, fumed silica, which can be added in a proportion of preferably 0.5 to 5% by weight (based on the total weight of the fiber composite material composition).

A pickup is preferably cast into the sound-generating sheet.

The pickup can be, for example, a sensor that reacts to pressure or movement and outputs a voltage. The pickup is preferably cast in the front, thinning end of the sheet. The particularly preferred installation position is approximately 5 to 10 mm behind the thin end of the sheet. An alternative installation position is approximately 5 to 30 mm behind the thin end of the sheet, preferably approximately 5 to 20 mm behind the thin end of the sheet.

The pickup is preferably positioned parallel to the flat surface, that is to say the lower surface of the sheet. Alternatively, the pickup can also be parallel to the cut-out, i.e. the oblique surface of the sheet.

In a preferred embodiment, this pickup is a piezo film.

The pickup, in particular the piezo film with wiring, is preferably cast into the sheet during manufacture.

In an alternative embodiment, when the sheet is cast, a cutout for the sensor is cast and this is installed after it has hardened. The sound-generating sheet therefore preferably has a cutout for a pickup. If the sensor is retrofitted, it can be cast or glued. In a preferred embodiment, the cutout for the sensor and its connections is designed such that the connections comprise a flat plug connection.

In a further embodiment, the signal is not transmitted via cable, but wirelessly. For this purpose, in addition to the sensor, a suitable wireless signal transmission system including battery or accumulator is installed in the sheet, which must be so slow that live transmission is possible without perceptible delays.

The sound-generating sheet with pickup is suitable on the one hand as a microphone replacement to enable, for example, an almost feedback-free, as close to natural as possible transmission on stages, and on the other hand the sensor sheet can also be used for educational purposes, for example to measure the frequency and strength of the player's tongue. In conjunction with a suitable app, the sensor sheet can be used as a signal source for a large number of applications that were either previously not possible or for which a microphone had previously been used. In addition, the sensor sheet can also be used to control synthesizers for pop, rock, jazz and entertainment music, but also for modern, contemporary compositions.

The present invention also relates to a musical instrument, in particular a wind instrument, preferably a woodwind instrument, in particular a clarinet, saxophone, oboe or bassoon, particularly preferably a clarinet or saxophone, comprising a tone-generating sheet according to the invention.

The present invention also relates to the use of a fiber composite material, the fiber composite material containing a thermosetting plastic as a matrix and reinforcing fibers, the proportion of reinforcing fibers being at least 2% by weight and at most 30% by weight for producing a clay-producing sheet, in particular one clay-producing sheet according to the invention.

A manufacturing process has been developed for sound-producing blades for musical instruments with flaps, counterblocks or flaps. Although developed as sound-producing blades for musical instruments with flaps, counterblows or punch tongues, this process can also be used to produce other shapes and parts for musical instruments, such as bridges for string and plucked instruments, mouthpieces for wood and brass instruments, tuning pegs for stringed instruments, and body parts for brass, woodwind and string instruments and much more.

1. a) Mischen der Matrixkomponenten und der Verstärkungsfasern und erhalten einer Mischung;
2. b) Einfüllen der Mischung in eine Form aus zwei Teilen, wobei die Form so positioniert ist, dass die in der Form sich das formende tonerzeugende Blatt aufrecht vertikal in der Form stehen, wobei bevorzugt die Blattspitze unten und das dicke Blattende oben positioniert ist;
3. c) Entgasen der Mischung durch Anlegen eines Unterdrucks;
4. d) Aushärten lassen der Mischung in der Form.

The present invention also relates to a method for producing a tone-generating sheet, in particular a tone-generating sheet according to the invention, comprising the steps:

1. a) mixing the matrix components and the reinforcing fibers and obtaining a mixture;
2. b) filling the mixture into a two-part mold, the mold being positioned so that the clay-forming sheet forming in the mold is upright vertically in the mold, preferably with the tip of the blade at the bottom and the thick end of the blade at the top;
3. c) degassing the mixture by applying a vacuum;
4. d) Allow the mixture to harden in the mold.

• e) Trennen der beiden Teile der Form, wobei das aus der ausgehärteten Mischung gebildete Blatt in einem der beiden Formteile verbleibt;
• f) Abschleifen der flachen Seite des tonerzeugende Blatts;
• g) Entfernen des zweiten Formteils;
• h) Tempern des tonerzeugende Blatts bei mindestens 70 °C, bevorzugt bei mindestens 75°C, besonders bevorzugt bei höchstens 100°C.

The method preferably has one or more of the following steps below:

• e) separating the two parts of the mold, the sheet formed from the hardened mixture remaining in one of the two mold parts;
• f) grinding the flat side of the clay-producing sheet;
• g) removing the second molded part;
• h) annealing the clay-producing sheet at at least 70 ° C, preferably at least 75 ° C, particularly preferably at most 100 ° C.

In mixing step a) all components of the later clay-producing sheet are mixed. Preferred components are disclosed in connection with the clay-producing sheet of the invention. The matrix can in particular be produced from mixing two components which subsequently harden as a result of the mixing, in particular as resin and hardener. Suitable matrix components are known to the person skilled in the art, for example isocyanate and polyol in the case of a polyurethane matrix.

In a preferred embodiment, step a) after the mixing comprises degassing by vacuum. In a preferred embodiment, step a) before and / or after the mixing comprises degassing by vacuum. In a particularly preferred embodiment, step comprises a) before and after mixing, degassing by vacuum. In the case of degassing before mixing, the reinforcing fibers are preferably added to the resin component, then degassed and then the degassed resin component is mixed with the hardener.

A vacuum below 0.8 bar is preferably used in the degassing in step c) and / or the optional degassing in step a). A vacuum below 0.5 bar is preferably used in the degassing. A vacuum below 0.3 bar is preferably used in the degassing. A vacuum between about 0.05 bar and 0.2 bar is preferably used in the degassing.

When pouring the sheet, a pickup can preferably also be cast in.

Further preferred embodiments result from the examples and the subclaims, without these being to be understood as restrictive.

• Es wurden tonerzeugende Blätter aus Polyurethan hergestellt. Das Polyurethan hatte ausgehärtet eine Dichte von etwa 1,2 g/cm³.

Example: Production of a clay-producing sheet from polyurethane with carbon fibers:

• Clay-producing sheets were made of polyurethane. The cured polyurethane had a density of approximately 1.2 g / cm ³ .

For the production, about 0.2 mm long carbon fibers were added to the corresponding isocyanate and the isocyanate was degassed at below 0.3 bar. The isocyanate was mixed with an appropriate polyol. The carbon fiber content in the mixture was about 5.8% by weight.

The mixture was degassed in the mixing vessel at below 0.8 bar. The volume in the mixing vessel increased 5 to 10 times as a result of the increase in the air inclusions in the mixture and then collapsed because the air bubbles collapsed. The vacuum was then released and the mixture was filled.

The mixture was poured into molds. The leaves were cast in such a way that the leaves stood upright vertically in the form. The tip of the sheet was at the bottom and the thick end of the sheet was at the top. Between 15 and 21 sheets were preformed in one mold. However, the shape size can be expanded as required.

The molds for this were made in-house and are interchangeable after a certain number of uses because they are reproducible. The shapes are designed in such a way that they can be stacked and any size (alto saxophone, tenor saxophone, clarinet, etc.) can be combined as required.

After filling the mixture into the mold, degassing was carried out again. This is advantageous to get bubble-free parts later.

After curing and separating the different shapes with the different sizes, the clay-producing leaves were ground in the shape on the flat side in order to reduce or even prevent the formation of drops when playing the leaves.

After removal from the mold, the sheets were placed in a tempering oven at 80 ° for three hours. This was followed by cutting the leaves with a small circular saw, deburring, milling the cut and cutting to length. After that, the leaves were ready.

The blades produced a good sound, were inexpensive to manufacture due to the process used, and had a stiffness comparable to that of natural wood.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 9322761 A1 [0006]

Claims (15)

Sound generating sheet for a musical instrument, wherein the sound generating sheet consists of a fiber composite material, the fiber composite material containing a thermosetting plastic as a matrix and reinforcing fibers, the proportion of reinforcing fibers being at least 2% by weight and at most 30% by weight. Sound generating sheet after Claim 1 , the sound-generating sheet being for a woodwind instrument, preferably for a clarinet or a saxophone. A sound generating sheet according to any one of the preceding claims, wherein the reinforcing fibers are carbon fibers or glass fibers. Sound generating sheet according to one of the Claims 1 and 2nd , wherein the reinforcing fibers are natural fibers. A sound generating sheet according to any one of the preceding claims, wherein the reinforcing fibers have a length of at least 0.05 mm and at most 1 mm. A sound generating sheet according to any one of the preceding claims, wherein the reinforcing fibers have a length of at least 0.1 mm and at most 0.5 mm. A sound-generating sheet according to any one of the preceding claims, wherein the thermosetting plastic is formed from a polyurethane or an epoxy resin. Sound generating sheet after Claim 7 , wherein the epoxy resin is an epoxy resin based on renewable raw materials. A sound generating sheet according to any one of the preceding claims, wherein the fiber composite contains at least 0.4% by weight and at most 15% by weight of color paste. A sound-generating sheet according to any one of the preceding claims, wherein the proportion of reinforcing fibers is at least 3% by weight and at most 10% by weight. A clay-producing sheet according to any one of the preceding claims, wherein the duromer has a density of at least 0.5 g / cm ³ and at most 5 g / cm ³ . Sound generating sheet according to one of the preceding claims, wherein a pickup is cast into the sound generating sheet. Sound-generating sheet according to one of the preceding claims, producible in a process according to Claim 15 . Use of a fiber composite material, the fiber composite material containing a plastic as a matrix and reinforcing fibers, the proportion of reinforcing fibers being at least 2% by weight and at most 30% by weight, for producing a clay-producing sheet. Method for producing a tone-generating sheet, in particular a tone-generating sheet according to one of the Claims 1 to 12th comprising the steps of: a) mixing the matrix components and the reinforcing fibers and obtaining a mixture; b) filling the mixture into a two-part mold, the mold being positioned so that the clay-forming sheet forming in the mold is upright vertically in the mold, preferably with the tip of the blade at the bottom and the thick end of the blade at the top; c) degassing the mixture by applying a vacuum; d) Allow the mixture to harden in the mold.