EP2025484B1 - Method for producing a moulded part, in particular for the construction or furniture industry - Google Patents

Abstract

The method of producing a molded body (50) for construction or furniture industry, comprises mixing a mixture of mineral- or wood fibers, wood flour and/or wood-chips with a bonding agent such as synthetic resin and converting to a molding material by drying at 50[deg] C, where the molding material after drying contains a humidity content of 7-10 wt.%, and forming the molded body from the molding material at 100-200[deg] C. The mold body has a residual moisture of less than 5 wt.%. The bonding agent comprises acrylic, copolymer, styrene or water. The method for producing a molded body (50) for construction or furniture industry, comprises mixing a mixture of mineral- or wood fibers, wood flour and/or wood-chips with a bonding agent such as synthetic resin and then converting to a molding material by drying at 50[deg] C, where the molding material after drying contains a humidity content of 7-10 wt.%, and forming the molded body from the molding material at 100-200[deg] C. The mold body has a residual moisture of less than 5 wt.%. The molding material is filled in a pressing tool and is pressed with a pre-determined temperature for 1 minute with a pressure of 20-50 bar. The mixture comprises mineral- or wood fibers, wood flour and/or wood-chips. The bonding agent comprises acrylic, copolymer, styrene or water. The molding material before drying comprises: wood fibers (25-50%), mineral fibers (0-25%) and bonding agent (50-65%); wood chips (50-65%), wood flour (0-10) and bonding agent (30-50%); or mineral fibers (35-50%), graphite and/or mica (0-15%) and bonding agent (50-65%). An independent claim is included for a molding material for producing a molded body.

Description

The present invention relates to a method for producing a shaped body or a component, in particular for the construction or furniture industry.

In order to connect a plurality of wooden components in a simple manner, in particular in timber construction, fastening elements for connecting the wooden components are provided in the area of the connection point. For example, so-called nail plates or nail binder plates can be used for this purpose. Such nail plates usually have a support plate made of steel with attached nail elements.

In particular, on the outer sides of wooden components attached nail plates have the disadvantage that in the case of a fire in a relatively short time a total failure of the support structure, such as a roof rack, occurs. This is mainly due to the fact that in a fire initially at a temperature up to about 250 ° C, the heat introduced via the existing steel sheet nail plate and the nail elements in the wood component and there causes charring and then coking of the wood areas around the individual nail elements around. After a rise in temperature within a few minutes in a range of 600 ° C to 800 ° C then softens the existing sheet steel support plate of the nail plate, which leads to a sudden total failure of the support plate and thus the wooden support structure.

Further, conventional moldings or components such as used in the construction or furniture industry pressboard have the disadvantage that in such plates swelling occurs. This is mainly due to the fact that inexpensive binders are used, for example, urea-formaldehyde-based, but which are slightly soluble in water, which then comes to a source.

The DE 1 808 375 A1 discloses a method for producing a material, in which the raw materials, in particular wood chips, are glued with binders, preferably aminoplasts, their homologs and mixed resins in an aqueous system and hot pressed into sheets or moldings. Here, the raw materials are dried down after gluing to a moisture content of less than 10% and then pressed. In turn, urea-formaldehyde resins in an aqueous solution are used as binders.

The US 6,368,528 B1 discloses a method of forming a composite body wherein fiber material is mixed with a resin-based binder. Subsequently, this mixture is dried to a moisture content of about 6 to 14 wt .-% and formed into a mat. Then, the surface of the mat is coated with an aqueous solution comprising, among others, a humectant, a mold release agent, a set retarder and, optionally, a thermoplastic resin. Finally, the mat is processed under heat and pressure to form a shaped body. For the binder it is an amino resin or a phenol-formaldehyde resin.

The invention has for its object to provide measures by means of which universally applicable moldings or components for the construction and furniture industry can be formed, which preferably have improved properties in terms of fire protection and / or the source protection. In particular, a molded body or component and a molding compound intended for this purpose should be specified and manufactured for this purpose.

To solve this problem, a method with the features of the appended claim 1 is proposed.

Thus, the residual moisture contained in the still moist molding composition after mixing in a moisture content of about 2 wt .-% to about 20 wt .-% is meant that the matched to this moisture content binder in the molding material is not yet "activated" and is activated only at later temperatures at a temperature of about 50 ° C to about 250 ° C. In this molding, the adhesive forces provided by the binder exert their effect and hold the batch-binder mixture together. It has been found that in order to activate the binder, a temperature in the said temperature range is suitable, since at this temperature, in particular with a copolymer-containing binder of this copolymer can be activated in a suitable manner. Thus, by generating the binder ingredients of the present invention, the process of drying to obtain the moisture content of from about 2% to about 20% by weight, and molding of the molding composition at a temperature of from about 50 ° C to about 250 ° C achieved the above synergistic effect.

In tests, good results were achieved at a temperature of about 80 ° C to about 220 ° C. The best results were obtained in experiments at temperatures of about 100 ° C to about 200 ° C. The temperature range to be selected for shaping, for example by means of pressing, is selected according to the composition of the batch. For example, a higher temperature can be used for chipboard than for fiberboard. For example, tests with particleboard have shown that a pressing temperature of about 200 ° C with a pressing time of 2 min. is suitable, provided that in this period the temperature in the core region of the molding body does not exceed about 150 ° C. On the other hand, a lower temperature of up to about 180 ° C. is possible with fiberboards, in particular with a mineral fiber base.

Depending on which of the aforementioned temperature ranges or temperatures is used, after drying different moisture contents achieved for the molding material or after molding different residual moisture contents for the molding.

In a preferred embodiment, the mixture is mixed with a water-containing and thus "wet" binder, whereby quasi a moist mass or a moist pulp is formed. In the mixing process, the constituents of the batch, that is to say the fibers, chips and / or the powder, are at least partially wetted with the binder. This can lead to an impregnation of at least part of the batch constituents. As a result, with regard to the finished molded body, a swelling-inhibiting effect can be achieved. This is particularly advantageous in the case of wood chips, which swell strongly without such impregnation by the binder.

In order to achieve an even higher swelling protection for the finished molded body, in a preferred embodiment, a certain proportion of mineral fibers are provided for the mixture, since they do not absorb water. In other words, a particular source protection can be effected in particular by selecting the mineral fiber content. In addition, such mineral fibers also have a fire-retardant effect and are therefore also advantageous in terms of fire protection aspects.

The above-mentioned "wet mass" forms a kind of intermediate, which is then dried to obtain the molding material. This preferably granular, substantially dry molding material may also be referred to as dry mass. Preferably, the term "dry" is understood to mean a certain residual moisture inherent in particular wood fibers. In a preferred embodiment, this residual moisture can be at least partially reduced at the wet wetted sites of the wet mass in the drying process.

In the state after drying the mixture of mixture and binder, that is in the presence of the molding composition, the binder contained in the molding composition is substantially water-insoluble, in particular because it has not yet been "activated" by means of temperature. The activation of the binder can then take place by the shaping process for shaping the shaped body from this molding composition, preferably by hot pressing.

In a preferred embodiment, an at least fire-retardant and / or at least one swelling-inhibiting effect of the molding compound and thus of the finished molding can be achieved. This is preferably done, as already indicated above, by adding mineral fibers to the mixture. Such mineral fibers are less prone to swelling. Further, the binder impregnates the mineral fibers. Furthermore, by means of the mineral fibers at least a fire retardant effect can be achieved.

The term "at least fire-retardant" in the definition of the shaped body and / or the component defined below is to be understood in the sense of the present invention that the shaped body or the component is formed from a building material, material, material or composition which is at least hardly inflammable within the meaning of class B1 of DIN 4102 Part 1. Optionally, the molded body or the component and the fire protection technically higher requirements of class A, A1 or A2 meet, that is, for example, be formed from non-combustible material. Such a shaped body or the component preferably fulfills the requirements of the fire resistance class F30 or the higher requirements of the fire resistance classes F60 to F180. In this way, the molded body or the component can fulfill its function in case of fire for at least 30 minutes (class F30) or depending on the material used longer. In general, however, it is already a great advantage if, in the event of a fire, in particular a component is capable of carrying out at least 30 minutes to the extent that persons located therein can leave the building or be evacuated and more time is available for extinguisher search.

Preferred developments of the method according to the invention are the subject of the dependent claims 2 to 9.

In a preferred embodiment of the method according to the invention, the shaped body is molded from the molding compound at a temperature of about 80 ° C to about 220 ° C, preferably at a temperature of about 100 ° C to about 200 ° C.

In a further preferred embodiment of the method, the molding composition after drying has a moisture content of about 5 wt .-% to about 12 wt .-%, preferably from about 7 wt .-% to 10 wt .-%, on.

It is further provided that the shaped body is formed from the molding composition in such a way that the molding has a residual moisture content of approximately less than 10% by weight, preferably of approximately less than 5% by weight. This reduction of the moisture content can be achieved for example by hot pressing.

Further advantageous is a binder with a weight fraction of acrylic, styrene and / or copolymer of about 50 to 75% by weight and a weight proportion of water of from about 25% to about 50% by weight. The component acrylic is preferably in the form of acrylic resin, preferably as a modified acrylic resin. The binder Includes a modified acrylate-styrene copolymer emulsion. Such an emulsion is available under the trade name NeoCryl (for example NeoCryl XK series)

In a further preferred embodiment, the mixture comprises mineral fibers, wood fibers, wood flour and / or wood chips. It is also possible to add additives such as kaolin, graphite and / or mica.

In a preferred application, the blend comprises from about 25% to about 50% by weight wood fibers, from about 0% to about 25% by weight mineral fibers, and from about 50% to about 65% by weight. Binder. Alternatively, the blend may comprise about 50% to about 65% by weight wood chips, about 0% to about 10% by weight wood flour, and about 35% to about 50% binder by weight , Also alternatively, the blend may contain from about 35% to about 50% by weight mineral fibers, from about 0% to about 15% by weight graphite and / or mica, and from about 50% to about 65% by weight. -% binder. The use of the abovementioned constituents constitutes a cost-effective and easily manageable measure, since the associated raw materials are available in sufficient form, for example as residual or waste materials, and / or are produced for recycling in recycling processes. For example, in a mixture of about 50 wt .-% of mineral fibers and about 50 wt .-% wood fibers or wood shavings a wood-like structure of the molding can be achieved, resulting in versatile applications in the construction or furniture industry.

The crushing is done for example by grinding or shredding. The crushing is preferably carried out after drying. In particular, batch components such as chips can be broken. The moisture from the chips can enter or leave these fractures.

Furthermore, it can be provided that the molding compound is dried at a temperature of up to about 100 ° C, preferably at a temperature of up to about 50 ° C, for example by means of hot air.

With regard to the shaping can be provided that the shaped body is formed by extruding or pressing the molding material. In the pressing or hot pressing, for example, the above temperatures are used.

In a preferred embodiment, the molding material is introduced into a pressing tool and pressed at a predetermined temperature over a predetermined period of time at a predetermined pressure. Advantageously, the molding compound is pressed at a pressure of about 20 to 50 bar. Preferably, the molding compound is pressed at a temperature of about 100 ° C to about 200 ° C.

In preferred application of the method, a plate-shaped molded body is formed. It is advantageous if the molding compound is pressed for a period of at least one minute. Such a plate can serve as a fire protection board. In principle, however, any shape, as they are known in the construction or furniture industry, for the molding be provided. The shape may, for example, be directed to a component to be covered or covered, in particular a component in the sense of a fastening element.

A molding composition for producing a shaped article according to claim 1 is characterized by a mixture of a mixture of fibers, chips and / or powder and a binder, wherein the molding composition after drying the mixture has a moisture content of about 2 wt .-% to about 20 wt .-% having.

Advantageously, the mixture comprises or consists of mineral fibers and / or powder and a binder.

In a preferred embodiment, the molding composition has a moisture content of about 5 wt .-% to about 12 wt .-%, preferably from about 7 wt .-% to about 10 wt .-%, on.

With regard to the mixture, the binder and their mixing, also in various combinations, reference is made to the above statements.

In a method for producing a component, in particular for fire protection in the connection of components, a molded body is pressed onto a support body, so that the support body and the molded body are positively and / or materially connected to each other.

With this method, it can be achieved, for example, that at the same time an at least partial shaping of the shaped body takes place with the pressing on of the shaped body onto the supporting body, so that a further reduction of the method steps is achieved. In addition, preferably one and the same tool for pressing and shaping can be used here. Thus, the number of required tools can be further reduced.

In a preferred embodiment, the shaped body is pressed onto the supporting body such that at least one area of the shaped body is pressed into an opening of the supporting body. Thus, on the one hand, the shape of the shaped body can be adapted to the shape of the supporting body. On the other hand, it can be provided in a further development of the method that the region of the shaped body is pushed so far into the opening of the support body, so that in the region of the opening, the positive connection of support body and molded body is formed. Preferably, the support body comprises a plurality of openings or recesses, in which case a positive connection can then be achieved at several points.

In a particularly preferred embodiment of the method, a component, in particular a perforated plate, inserted into a mold and the molded body introduced into the mold and pressed onto the support body such that the molded body is connected to the support body positively and / or cohesively as a support body. In this case, the molded body can be introduced into the mold in already substantially consolidated form or else in the form of the above-mentioned molding compound. For example, the mold can be closed after inserting the support body or component and then filled the molding material in the closed mold into a corresponding cavity. Alternatively, the shaped body, for example in the form of a plate, placed on the support body or the component and then the mold getting closed. When introducing the shaped body, it is preferably provided that the shaped body has approximately 1.5 to 3 times the volume of the subsequent volume of the shaped body after completion of the pressing process. Preferably, the molded body to be connected to the support body is produced according to one of claims 1 to 9.

A component for fire protection of components, in particular of wooden components, comprises a support body and a molded body, wherein the support body and molded body by means of the above-mentioned method for producing a component in which a molded body is pressed onto a support body, so that the support body and the molded body positively / or cohesively connected to each other, are processed. In a preferred embodiment, the support body is a perforated plate and the molded body is a fire protection plate, which is positively and / or materially connected to the support plate.

Preferably, the support body is designed as a perforated plate. Here, a plurality of holes, openings or openings is provided in the perforated plate.

The above-described molding compound, the molded body and the component are preferably made of an at least fire-retardant and / or at least swelling-inhibiting material or such a material composition. The molding or the molding compound may consist of at least fire-retardant material, that is to say be at least flame retardant according to the class B1 of the standard DIN 4102 Part 1. Reference is made to the above statements.

For example, the molded body or the component meets the requirements of the fire resistance class F30, that is holds in case of fire stood for at least 30 minutes. Depending on the material used for the molding compound, the higher requirements of the fire resistance classes F60 to F180 can also be met. In general, however, it is already of great advantage if a supporting structure or a building is at least 30 minutes to the extent that persons located therein leave the building or can be evacuated and more time for deletion attempts exists.

The above-mentioned methods for producing a molded article and for producing a component may be combined with each other. Thus, for example, the molded body can first be produced and then connected to the support body for further production of the component.

Fig. 1

eine Holztragkonstruktion mit einem Bauelement;

Fig. 2

einen Schnitt durch die Holztragkonstruktion entlang der Linie II-II in Fig. 1;

Fig. 3

eine perspektivische Darstellung des Bauelementes gemäß Fig. 1,

Fig. 4

einen Querschnitt durch das Bauelement gemäß den Figuren 1 bis 3, und

Fig. 5

eine vergrößerte Ansicht des Details V aus Fig. 2.

The invention will be further explained with reference to several embodiments and the drawings. Here are shown schematically:

Fig. 1

a wooden support structure with a structural element;

Fig. 2

a section through the timber support structure along the line II-II in Fig. 1 ;

Fig. 3

a perspective view of the device according to Fig. 1 .

Fig. 4

a cross section through the device according to the FIGS. 1 to 3 , and

Fig. 5

an enlarged view of the detail V off Fig. 2 ,

Fig. 1 shows a wooden support structure, wherein a component 10 is provided for fire protection of the connection of components 12 in the form of five wooden components. This component 10 comprises the wooden components 12 on both sides.

The component 10 comprises, as a supporting body 20, a perforated plate and, as a shaped body 50, a protective plate in the form of a fire protection plate. This perforated plate 20 comprises holes or openings 30 arranged adjacent to one another in a plurality of rows. The openings 30 can serve at least in partial regions of the perforated plate 20 for the passage of fastening elements 32 in order to protect the components 12 by means of the component 10.

Furthermore, the support plate 20 comprises an inner side 22, an outer side 24 and a side surface 26. The outer side 24 faces the timber components 12 in the assembled state. The inside 22 is facing away from the wooden components 12. The side or end surface 26 extends circumferentially of the support plate 20 circumferentially.

Between the openings 30 remaining plate areas 28 of the support plate quasi webs or strips, which serve in the installed state for dimensional stability of the device 10.

As is clear from the FIGS. 2 to 4 results, the protective plate 50 rests on the inside 22 of the support plate 20 and is positively connected to the support plate 20. The protective plate 50 is preferably formed from a structure comprising mineral fibers and binder and has a thickness of about 1 mm to about 20 mm, preferably from about 5 mm to about 12 mm. This protective plate 50 meets the requirements of building materials class B1 of DIN 4102 Part 1 requirements. In this way, the wooden support structure according to Fig. 1 in which several wooden components 12 are connected to each other by means of a nail binder plate, keep in case of fire for at least 30 minutes. Furthermore, as a result of the mineral fibers contained in the material composition, a swelling-inhibiting effect, whereby the protective plate 50 also causes swelling protection.

How, in particular, the Fig. 4 can be removed, the protective plate 50 in the region of a plurality or all openings 30 of the support plate 20 has a projection 52 which projects into the respective opening 30 for the positive connection of the protective plate 50 and the support plate 20. The respective projection 52 may have a height that is less than, greater than, or equal to the depth of the associated opening 30. In Fig. 4 the height of the projections is slightly smaller than the depth of the opening 30 or substantially corresponds to the depth of the opening 30th

In order to produce the shaped body, in particular the protective plate 50, a mixture of fibers, chips and / or powder is mixed with a binder and processed by drying to a molding compound. After drying, the molding composition has a moisture content of about 2 wt .-% to about 20 wt .-%. From this "dried" molding compound, the molded body 50 is then molded at a temperature of about 50 ° C to about 250 ° C. In tests, good results were achieved at a temperature of about 80 ° C to about 220 ° C. The best results were obtained in experiments at temperatures of about 100 ° C to about 200 ° C.

The temperature range to be selected for shaping, for example by means of pressing, is selected according to the composition of the batch. For example, a higher temperature can be used for chipboard than for fiberboard. For example, tests with particleboard have shown that a pressing temperature of about 200 ° C with a pressing time of 2 min. is suitable, provided that in this period, the temperature in the core region of the molding does not exceed about 150 ° C. On the other hand, a lower temperature of up to about 180 ° C. is possible with fiberboards, in particular with a mineral fiber base.

Depending on which of the abovementioned temperature ranges or temperatures is used, different moisture contents for the molding compound or, after molding, different residual moisture contents for the molding 50 are achieved after drying.

In particular, the range of moisture content of the molding composition after drying is in the range of about 5% to about 12%, preferably in the range of about 7% to about 10%, by weight.

In order to obtain a suitable molding composition, three variants are explained below:

In the first variant, the mixture comprises as constituents substantially from about 25% to about 50% by weight wood fibers and from about 0% to about 25% by weight mineral fibers. In a second variant, the blend comprises about 50% to about 65% by weight wood chips and about 0% to about 10% by weight wood flour. The mixture according to variant 3 comprises about 35 wt .-% to about 50 wt .-% mineral fibers and about 0 wt .-% to about 15 wt .-% graphite and / or mica.

In all three variants mentioned above, a composition comprising the constituents acrylic, copolymer and water is added to the respective mixture as binder. As binder is a modified acylate-styrene copolymer emulsion (available under the trade name "NeoCryl XK series"), in particular with a weight fraction of acylate, styrene and copolymer of about 50 wt .-% to about 75 wt .-% and a weight fraction of water of from about 25% to about 50% by weight. Mixture and Binders are then mixed in a mixing device in the cold state until a moist mass or a slurry is obtained.

This "wet" mass is then dried in the variants 1 and 3 at a temperature of up to about 50 ° C and then comminuted into particles having a maximum size or maximum length of about 1 mm. This crushing can be done by shredding or grinding.

After this treatment, the molding compound now in the form of a dry powder or in the form of dry chips is introduced into a mold. In this case, about 1.5 to 2 times the volume of molding compound (in comparison to the later obtained after the pressing process volume of the molding material) can be introduced. After closing the mold, in all variants with a pressure of about 20 to 50 bar and a temperature of in the range of about 50 ° C to about 250 ° C, in particular at a temperature in the above ranges, the pressing operation is performed. The duration of the pressing process is selected such that the thickness of the subsequent shaped body 50 is estimated to be at least one minute. After completion of the pressing process and at least partially cooling to a maximum of about 80 ° C, the molded body 50 can be removed from the mold.

In a preferred embodiment, the cavity of the mold is designed accordingly, so that a plate-shaped molded body 50 is malleable.

Hereinafter, on the basis of the molded article 50 produced by the above-explained method, a method of manufacturing the device will be described 10 explained. These two methods can also be combined into a common procedure.

The molded body 50 produced is plate-shaped and represents the protective plate 50 shown in the figures. In order to be able to achieve the desired connection between the support body 20 in the form of the support plate and the molded body 50 (protective plate), a pressing tool is provided. After opening the pressing tool, the perforated plate 20 is inserted into the pressing tool. Subsequently, the shaped body 50 is placed on the inner side 22 of the perforated plate 20. After closing the pressing tool, the protective plate 50 is pressed onto the perforated plate 20 over a predetermined period of time and with a predetermined pressing pressure in such a way that the perforated plate 20 and the protective plate 50 are connected to one another in a form-fitting and / or cohesive manner.

The cohesive connection can be achieved on the one hand by a corresponding nature of the molding compound or the molding or by a subsequent application of an adhesive layer on the inside 22 or the protective plate 50.

The form-fitting connection is achieved in that areas of the molded body 50 located in the region of the openings 30 during pressing are pressed into the respective opening or recess 30 of the support plate 20. In this way, the projections 52 are formed. Due to the thereby achieved positive connection between the perforated plate 20 and the protective plate 50 but can be dispensed with in principle an additional cohesive connection.

The at least fire-retardant and / or at least swelling-inhibiting component 10 thus formed is thus protected in such a case on the fireproofed outside with the molded body 50 (protective plate), that this compound is maintained even in case of fire over a longer period. Thus, in case of fire, valuable time can be gained for leaving or evacuating a building and for the extinguishing work.

Fig. 5 shows an enlarged view of the detail V from Fig. 2 ,

The protective plate 50 is pressed onto the perforated plate 20. In this case, the projections 52 extend into several or all openings 30. In this way, a positive connection of the perforated plate 20 and the protective plate 50 is achieved. In assembled state according to Fig. 5 is located on the outside of the protective plate 50, the perforated plate 20. In case of fire prevents the protective plate 50 due to their good fire retardant effect and on the perforated plate 20 that high temperatures are registered in the components 12.

LIST OF REFERENCE NUMBERS

10

module

12

component

20

supporting body

22

inside

24

outside

26

side surface

28

plate area

30

opening

32

fastener

40

Truss plate

50

moldings

52

head Start

Claims (9)

1. Method for producing a moulded part (50), in particular for the construction or furniture industry,
   wherein a mixture comprising mineral fibres and/or wood fibres is combined with a bonding agent comprising a modified styrene-acrylic copolymer emulsion and
   is dried to produce a moulding compound, whereby, after drying, the moulding compound has a moisture content from approximately 2 wt.% to approximately 20 wt.%,
   the moulding compound is reduced
   and the moulded part (50) is formed from the moulding compound at a temperature from about 50°C to approximately 250°C so that the moulded part has a residual moisture content of somewhat less than 10 wt.%.
2. Method according to claim 1, characterised in that the moulding part (50) is formed from the moulding compound at a temperature from approximately 80°C to approximately 220°C, preferably at a temperature from approximately 100°C to approximately 200°C.
3. Method according to claim 1 or 2 characterised in that the moulding compound is dried so that, after drying, the moulded compound has a moisture content of approximately 5 wt.% to approximately 12 wt.%, preferably of approximately 7 wt. % to 10 wt. %.
4. Method according to one of the claims 1 to 3 characterised in that the moulded part is moulded so that the moulded part has a residual moisture content of somewhat less than 5 wt.%.
5. Method according to one of the claims 1 to 4 characterised in that the mixture comprises wood flour and/or wood chips
6. Method according to one of the claims 1 to 5 characterised in that, prior to drying, the moulding compound comprises one of the following compositions:

   (a) from approximately 25 wt.% to 50 wt.% of wood fibres, from approximately 0 wt.% to 25 wt.% of mineral fibres and from approximately 50 wt.% to 65 wt.% of bonding agent;

   (b) from approximately 50 wt.% to 65 wt.% of wood chips, from approximately 0 wt.% to 10 wt.% of wood flour and from approximately 35 wt.% to 50 wt.% of bonding agent, or

   (c) from approximately 35 wt.% to 50 wt.% of mineral fibres, from approximately 0 wt.% to 15 wt.% of graphite and/or glimmer and from approximately 50 wt.% to 65 wt.% of bonding agent.
7. Method according to one of the claims 1 to 6 characterised in that drying takes place at a temperature of up to 100°C, preferably at a temperature of up to 50°C.
8. Method according to one of claims 1 to 7 characterised in that the moulding compound is filled into a pressing tool and is pressed at a predetermined temperature for a prescribed period of time and at a predefined pressure, in particular at a pressure of about 20 to 50 bar.
9. Method according to one of the claims 1 to 8 characterised in that the moulding compound is pressurised for a period of at least one minute.

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