Apparatus, system and method for producing molded articles

Abstract

The present invention shows and describes an apparatus (1) for producing molded articles, in particular from fiber composite materials, comprising a first press die (2), a second press die (3), and at least one membrane (4, 4') for contacting a workpiece (18), the first press die (2) and the second press die (3) being movable relative to one another between an open position and a closed position, and at least in the closed position, a cavity (5) for a working medium is formed between the membrane (4, 4') and the first press die (2) and / or the second press die (3), and a working space (8) for accommodating the workpiece (18) is formed between the first press die (2) and the second press die (3), in particular between the membrane (3) and the first press die (2) and / or the second press die (3), and the membrane (4, 4') has a membrane thickness, a longitudinal extension, and a lateral extension. In order to provide a device that allows pressure and / or temperature to be applied uniformly to molded articles having both complex and less complex geometries, it is proposed that the membrane (4, 4') has, in particular along its longitudinal and / or lateral extension, at least one elastically deformable base section (G, G') for contacting the workpiece (18) and at least one pre-plastically deformed forming section (F) for contacting the workpiece (18).

Description

[Technical Field]

[0001] The invention relates to an apparatus for producing molded articles, in particular from fiber composite materials, which comprises a first pressing tool (German: Presswerkzeug, English: pressing tool), a second pressing tool and at least one membrane for contacting a workpiece, the first pressing tool and the second pressing tool being movable relative to one another between an open position and a closed position, and at least in the closed position a cavity for a working medium is formed between the membrane and the first pressing tool and / or the second pressing tool, and a working space for accommodating a workpiece is formed between the first pressing tool and the second pressing tool, in particular between the membrane and the first pressing tool and / or the second pressing tool, and the membrane has a thickness, a longitudinal extension and a transverse extension.

[0002] The invention also relates to a system for producing moulded articles, in particular from fibre composite materials, comprising a workpiece and a device for producing moulded articles according to one of claims 1 to 21.

[0003] The invention also relates to a method for producing a moulded article, in particular from a fibre composite material, comprising the steps of a) providing a workpiece, b) providing an apparatus for producing a moulded article according to any one of claims 1 to 21, and c) applying pressure and / or temperature to the workpiece by means of the apparatus for producing a moulded article.

[0004] Fiber composites are composite materials that essentially consist of two main components: reinforcing fibers and a plastic ("matrix" or "resin") in which the fibers are embedded. By combining the two main components, it is possible to achieve a composite material with better overall properties than either of the two components alone. For example, the fibers contribute to the tensile strength of the composite due to their high tensile strength in the fiber direction. On the other hand, the matrix ensures that the fibers are held in place and protected from mechanical and chemical influences.

[0005] One of the many options for producing molded articles from fiber composite materials is based on the use of prefabricated intermediate products of fiber and resin (so-called "prepreg," short for "preimpregnated fiber"). In such intermediate products, the fibers contain a resin system that has not yet fully reacted, so that the intermediate product is still provided in a flexible form (e.g., in sheet form, roll). The prepreg is only shaped during the production of the molded article and is cured at high pressure and temperature by completing the chemical reaction. This step can be carried out, for example, in a press.

[0006] Prepregs are processed in large quantities, for example, in the aerospace industry. One processing challenge is that the aerospace industry often requires highly complex part geometries, for example, due to reinforcing components, such as stringers. The goal is also to reduce assembly costs, which can be achieved by using fewer, but larger, parts. The combination of complex geometries and large part dimensions places high demands on the equipment and methods used to produce these parts.

[0007] An apparatus and method for producing molded parts made of fiber composite materials are known, for example, from U.S. Pat. No. 5,623,499. Uniform pressure on the molded part to be produced can be achieved by an elastic membrane acting on the workpiece from which the molded part is to be formed and oil pressure acting on the membrane from the side of the membrane facing away from the workpiece. The membrane is thus pressed against the surface of the workpiece by the oil pressure and thus assumes the shape of the workpiece. This ensures that even curved workpiece or molded part surfaces are subjected to oil pressure on all sides, thereby ensuring that the force acting from the membrane on the workpiece surface is equal at all points, especially the force component acting perpendicular to the workpiece surface. However, a drawback of U.S. Pat. No. 5,623,499 is that the membrane can only be elastically deformed to a certain extent before damage occurs. Molded parts with complex geometries, especially those with strong changes in curvature and / or reverse curvature, cannot be produced with such an apparatus.

[0008] The use of such a "membrane press" for producing molded parts made of fiber composite materials is also known from Patent Document 2. However, a drawback of Patent Document 2 is that only a rigid wall is provided for contact with the workpiece or molded part. This rigid wall can be connected to a flexible membrane, but this flexible membrane is not intended for contact with the workpiece. In particular, in areas of the workpiece or molded part with less complex geometries, such a rigid wall cannot or does not sufficiently adapt to the geometry of the workpiece or molded part by elastic deformation, making it impossible to apply pressure and / or temperature uniformly. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] German Patent Application Publication No. 10 2017 113 595(A1) [Patent Document 2] U.S. Patent Application Publication No. 2016 / 0297153(A1)

[0010] The present invention is therefore based on the object of providing an apparatus, a system and a method for producing moulded articles, in particular from fibre composite materials, which allows for uniform application of pressure and / or temperature to moulded articles with complex and less complex geometries.

[0011] This object is achieved in an apparatus according to the preamble of claim 1, in which the membrane has, particularly along its longitudinal and / or transverse extension, at least one elastically deformable base section for contacting the workpiece, in particular the part to be produced, and at least one plastically pre-deformed forming section for contacting the workpiece, in particular the part to be produced. The combination of an elastically deformable base section, which can very well elastically adapt to the less complex geometry of the shape of the workpiece or the shape of the part to be produced from this workpiece, with a pre-plastically deformed forming section that has already been adapted to the particularly complex geometry of the shape of the workpiece or the shape of the part to be produced from this workpiece by pre-plastic deformation prior to applying pressure and / or temperature to the workpiece, makes it possible to expose geometries of different complexity to pressure and / or temperature in a particularly uniform manner.

[0012] The longitudinal extension of the membrane refers in particular to the extent of the membrane along its longitudinal axis, starting from a lateral side of the membrane. The lateral extension of the membrane refers in particular to the extent of the membrane along its lateral axis, starting from a longitudinal side of the membrane. The lateral extension of the membrane does not have to extend exclusively in the direction of the lateral axis, or may not extend at all in some sections. For example, if the membrane extends at least partially in an arc about its longitudinal axis, the lateral extension of the membrane extends proportionally in the direction of its lateral axis and proportionally in the direction of its height axis. The same applies to the longitudinal extension of the membrane. The height axis of the membrane is an axis perpendicular to the longitudinal axis and the lateral axis of the membrane. The longitudinal axis and the lateral axis of the membrane are also perpendicular to each other.

[0013] The apparatus includes a first, preferably upper, press die and a second, preferably lower, press die, although the apparatus may include additional press dies. The first and / or second press dies may be designed as a single unit or as an assembly. The first and / or second press dies are preferably made of metal, particularly nickel-rich steel, nickel-rich cast iron, or nickel-rich cast steel. The nickel content of each may be greater than 34%, preferably between 35.7% and 36.7% or between 40.8% and 43.6%. The use of metal, particularly steel, allows for a long press die life. In the case of steel, for example, Invar 36, this steel also has an extremely low thermal expansion coefficient. Therefore, the use of Invar allows for extremely precise production of molded parts, even when temperatures change during the pressing process. An even greater advantage can be achieved by specially adapted casting alloys, preferably nickel-rich cast iron or nickel-rich cast steel, which not only maintain a low maximum coefficient of thermal expansion throughout most of the heating and cooling process in the press cycle, but also match the requirements of the workpiece material, e.g., a (glass or carbon fiber reinforced) thermosetting material or a (glass or carbon fiber reinforced) thermoplastic material. Furthermore, the use of casting materials offers considerable economic advantages, since high-nickel alloy steels are very expensive and the reduction ratios in mold production are still often well above 50%, and usually even above 70 or 80%.

[0014] The first press die and the second press die are movable relative to each other between an open position and a closed position. This allows the press dies to be moved toward and away from a workpiece inserted into the press or a molded part produced from the workpiece. The first press die and the second press die are movable relative to each other, particularly along a movement axis between the open and closed positions. This ensures a defined movement of the press dies. In the open position, a workpiece can be inserted between the press dies or a finished molded part can be removed between the two press dies. In the closed position, pressure and / or temperature can be applied to the workpiece to produce a molded part from the workpiece.

[0015] The apparatus also includes at least one membrane. This membrane is provided for contacting the workpiece, in particular the molded part to be produced, and for applying pressure and / or temperature to the workpiece. For this purpose, the membrane is at least partially movable, in particular stretchable, in the direction of the working space. The membrane includes at least one base section and at least one forming section. The membrane may advantageously include at least two base sections, in particular a plurality of base sections, and / or at least two forming sections, in particular a plurality of forming sections. The base sections are elastically deformable, in particular linearly elastically deformable, and therefore can very well adapt to the shape of the workpiece or the molded part to be produced. In contrast, the forming section is pre-plastically deformed. This means that the shape is imprinted on the forming section by plastic deformation, in particular relative to the base section. The forming section is additionally plastically deformed relative to the base section as a result of the pre-plastic deformation. The pre-plastic deformation is carried out beyond the elastic limit of the material of the membrane. The pre-plastic deformation preferably produces plastic deformation at least on the side of the forming section adjacent to the cavity and / or at least on the side of the forming section adjacent to the working space, particularly across substantially the entire membrane thickness of the forming section. The shape of the forming section, particularly shaped by the pre-plastic deformation, advantageously differs from the basic shape of the membrane, particularly the basic shape of the base section, at least in the open position of the press die, particularly in the unloaded state of the membrane. The purpose of the pre-plastic deformation is to at least partially adapt the forming section to the shape of the workpiece or the shape of the molded article to be produced from the workpiece by the apparatus. The pre-plastic deformation allows the forming section to assume a shape that the membrane cannot achieve by elastic deformation, particularly linear elastic deformation, during the production of the molded article. Thus, as a result of the pre-plastic deformation of the forming section, a controlled adaptation of the shape of the forming section and thus the shape of the membrane is achieved, instead of uncontrolled plastic deformation of the membrane when pressure and / or temperature are applied. Uncontrolled plastic deformation of the membrane could result in damage to the membrane. The forming section does not have to be completely pre-plastically deformed, it is preferably sufficient that the forming section is at least partially pre-plastically deformed, preferably the majority of it.However, it may be advantageous if the forming section is substantially completely pre-plastically deformed.

[0016] Pre-plastic deformation of the shaping section does not mean, for example, the general plastic deformation of the entire starting material used for the membrane, for example in a rolling mill, or the plastic deformation that the membrane may undergo when applying pressure and / or temperature during the production of a shaped article. The shaping section is advantageously pre-plastically deformed, in particular relative to the base section, at least on the side of the shaping section adjacent to the cavity and / or at least on the side of the shaping section adjacent to the working space.

[0017] The base section and the shaped section of the membrane are arranged in particular along the longitudinal and / or transverse extension of the membrane. The base section and the shaped section advantageously extend along the longitudinal and / or transverse extension of the membrane. Preferably, the base section and the shaped section are adjacent to each other in particular along the longitudinal and / or transverse extension of the membrane.

[0018] The device may also include two or at least two membranes. The use of two or at least two membranes allows for easy transmission of pressure and / or temperature to the workpiece from different sides. Advantageously, the membrane thickness is at least 0.05 mm, preferably at least 0.2 mm, and in particular at least 0.25 mm. This ensures sufficient strength of the membrane. Alternatively or additionally, the membrane thickness is at most 4 mm, preferably at most 2 mm, and in particular at most 1.5 mm. This ensures sufficient flexibility of the membrane, particularly in the region of the base section. The membrane is preferably formed as a single piece and / or integrally, in particular from a single sheet metal. However, it may also be sufficient if the base section and the molding section are simply formed integrally with each other, in particular from a single sheet metal.

[0019] A cavity for the working medium is formed between the membrane and the first and / or second press die, at least in the closed position. This cavity may be formed between the membrane and the first and / or second press die in both the open and closed positions, preferably in each of the press dies. The cavity is preferably at least partially defined by the membrane and the first and / or second press die. The cavity advantageously has an equal thickness at all points between the membrane and the first and / or second press die, particularly along the longitudinal and / or lateral extension of the membrane. The cavity may be filled with a working medium, which may be, for example, a gas or a liquid. Pressure and / or temperature may preferably be applied to the working medium. The pressure and / or temperature applied to the working medium may be transmitted to the workpiece by the membrane. The cavity may advantageously extend in the direction of the working space. The cavity may be exposed to an oil pressure of at least 0.1 bar, preferably at least 2 bar, more preferably at least 6 bar, in particular at least 8 bar and / or at most 40 bar, preferably at most 26 bar, in particular at most 22 bar. The cavity may preferably be sealed by the first and / or second pressing dies and the membrane against an oil pressure of at least 4 bar, advantageously at least 8 bar, in particular at least 40 bar.

[0020] A working space for accommodating a workpiece is also formed between the first and second press dies, in particular between the membrane and the first and / or second press dies. This working space is preferably formed at least in an open position and / or at least in a closed position, in particular in each of the press dies. In this case, the workpiece can be introduced into the working space in the open position, and pressure and / or temperature can be applied to the workpiece in the closed position, in particular by the membrane.

[0021] According to a first embodiment of the device, it is provided that, at least in the open position, the forming section is pre-plastically deformed relative to the base section, particularly along the longitudinal and / or lateral extension of the membrane. Thus, the forming section has, compared to the base section, additional plastic deformation that allows the forming section to adapt to the complex geometry of the workpiece or part to be produced. Advantageously, at least in the open and closed positions, and preferably in all positions of the press die, the forming section is pre-plastically deformed relative to the base section.

[0022] According to a further embodiment of the device, the membrane is made of metal, preferably steel, particularly stainless steel. In simple cases, it may be sufficient to use stainless steel according to material specification 1.4301 to produce the membrane. However, it is preferable to use steel, particularly stainless steel, with good to excellent deep-drawing properties, i.e., so-called deep-drawing steel, to produce the membrane. The use of metal provides a sufficiently stable membrane that can withstand high pressures and / or temperatures, and the membrane itself has high thermal conductivity. Furthermore, metallic membranes can be elastically and plastically deformed. The use of metallic membranes with pre-plastically deformed sections makes it possible to produce molded parts with complex geometries under high pressures and / or temperatures, which is not possible with non-metallic membranes, such as silicone membranes. Silicone membranes can, for example, better conform to the complex geometries of the workpiece or molded part to be produced, but they can only withstand lower pressures and / or temperatures than metallic membranes. For example, the disadvantage of metal membranes, which are less flexible than silicone membranes, is compensated for in this case by a pre-plastically deformed forming section that is adapted to the complex geometry of the workpiece or section of the molded article to be produced. Advantageously, both the forming section and the base section are made of the same metal. The membrane may have a tensile strength of 300 to 850 MPa, in particular 310 to 540 MPa or 490 to 830 MPa. In particular, the membrane may have a tensile strength of 300 to 850 MPa, in particular 310 to 540 MPa or 490 to 830 MPa. - carbon in the range of approximately 0.16% to 0.22%; - silicon up to about 0.13%; - manganese in the range of approximately 0.2% to 0.4%; - up to approximately 0.25% nickel, - maximum of approximately 0.025% sulfur, - up to approximately 0.025% phosphorus, - maximum of approximately 0.15% chromium, - Aluminum in the range of approximately 0.02% to 0.07%; - maximum of approximately 0.2% copper, Iron and unavoidable impurities, residues For example, the membrane may be made from hot annealed or hot rolled steel strip according to GOST 2284-79.

[0023] Other steel alloys containing chromium, nickel and, advantageously, titanium and / or copper can also achieve good results.

[0024] A further embodiment of the device provides that the base section is more elastically deformable than the molding section and / or that the membrane, particularly the base section, is deformable by elastic deformation in the direction of the working space. This allows the base section to be particularly well adapted to the geometry of the workpiece or molded part to be produced. The greater elastic deformability of the base section compared to the molding section is particularly due to the pre-plastic deformation of the molding section. In particular, the base section is more linearly elastically deformable than the molding section. However, despite the pre-plastic deformation of the molding section, the molding section is preferably elastically deformable. Advantageously, the base section is more elastically deformable, particularly linearly elastically deformable, than the molding section, at least on the side of the base section adjacent to the cavity and / or at least on the side of the base section adjacent to the working space. In particular, the molding section is also more plastically deformed than the base section, at least in the open position. Due to the greater plastic deformation, the molding section is particularly well adapted to the geometry of the workpiece or molded part to be produced in advance. Alternatively or additionally, the membrane, particularly the base section, may be elastically deformed in the direction of the cavity.

[0025] According to one embodiment of the device, at least in the open position, the curvature of the shape of the forming section, particularly along the longitudinal and / or lateral extension of the membrane, is at least partially different from the curvature of at least one of the shape of the base section, preferably the curvature of the shape of the edge region of the base section adjacent to the forming section. This provides a pre-deformation of the forming section, which is adapted to the geometry of the workpiece or the formed part to be produced. In particular, the curvature of the shape of the forming section may differ from the curvature of at least one of the shape of the base section in terms of amount and / or sign. Thus, since the forming section has a change in curvature compared to the base section, the forming section and the base section extend at least partially in different directions from each other. The shape of the forming section or the shape of the base section refers to the general shape of the respective sections. Shape deviations, preferably at least second and / or at least third and higher order shape deviations as described in DIN 4760:1982-06, are not considered as part of the shape or curvature of the shape. A second-order shape deviation is waviness, and a third- to fifth-order shape deviation is roughness. Therefore, the curvature of the shape is not a membrane defect, particularly a surface defect. In particular, the curvature of the shape of the shaping section is at least partially smaller or larger than the curvature of at least one of the shapes of the base section, preferably the curvature of the shape of the edge region of the base section adjacent to the shaping section, by at least 1.05 times, preferably at least 1.25 times, more preferably at least 2 times, more preferably at least 4 times, more preferably at least 10 times, more preferably at least 25 times, more preferably at least 50 times, more preferably at least 100 times, more preferably at least 250 times, more preferably at least 500 times, more preferably at least 1000 times, more preferably at least 2500 times, more preferably at least 5000 times, in particular at least 10000 times.

[0026] The at least partial deviation of the curvature between the shape of the shaping section and at least one curvature of the shape of the base section is advantageously generated by a pre-plastic deformation of the shaping section relative to the base section, and therefore should not be, or at least should not substantially be, a deviation of the curvature due to, for example, elastic deformation of the membrane, in particular gravity.

[0027] According to one embodiment of the device, at least in the open position, the curvature of the shape of the molding section on the side of the molding section adjacent to the cavity is at least partially different from at least one curvature of the shape of the base section, preferably from the curvature of the shape of the edge region of the base section on the side of the base section adjacent to the cavity, and / or the curvature of the shape of the molding section on the side of the molding section adjacent to the working space is at least partially different from at least one curvature of the shape of the base section, preferably from the curvature of the shape of the edge region of the base section on the side of the base section adjacent to the working space. This provides a pre-deformation of the molding section that can be adapted to the geometry of the workpiece or molded part to be produced. In this case, it is particularly advantageous if both the curvature on each side adjacent to the working space and the curvature on each side adjacent to the cavity are different from each other, since this allows for a particularly wide range of adaptation of the molding section to the geometry of the workpiece or molded part to be produced.

[0028] A further embodiment of the device is characterized in that, at least in the open position, the curvature of the shape of the forming section, particularly along the longitudinal and / or lateral extension of the membrane, is designed at least partially opposite to the curvature of at least one shape of the base section, preferably the curvature of the shape of the edge region of the base section adjacent to the forming section. This provides a pre-deformation of the forming section that is adapted to the geometry of the workpiece or molded part to be produced. In particular, this provides a forming section that is pre-deformed to adapt to more complex geometries of the workpiece or molded part to be produced. Opposite curvatures mean that the curvatures have mutually different signs. For example, the base section may be curved to the left and therefore have a positive sign, while the forming section may be curved to the right and therefore have a negative sign, or may not be curved at all; in this case, the curvature is zero, i.e., the curvature has no sign. A positive sign, a negative sign, and no sign can each be considered as different signs.

[0029] The at least partially reverse curvature between the shape of the shaping section and at least one curvature of the shape of the base section is advantageously generated by a pre-plastic deformation of the shaping section, in particular relative to the base section, so that the reverse curvature should not, or at least should not, be caused by, for example, an elastic deformation of the membrane, in particular due to gravity.

[0030] According to one embodiment of the device, at least in the open position, the curvature of the shape of the molding section on the side of the molding section adjacent to the cavity is at least partially opposite to at least one curvature of the shape of the base section, preferably the curvature of the shape of the edge region of the base section adjacent to the molding section on the side of the base section adjacent to the cavity, and / or the curvature of the shape of the molding section on the side of the molding section adjacent to the working space is at least partially opposite to at least one curvature of the shape of the base section, preferably the curvature of the shape of the edge region of the base section adjacent to the molding section on the side of the base section adjacent to the working space. This provides a pre-deformation of the molding section that can be adapted to the geometry of the workpiece or molded part to be produced. In this case, it is particularly advantageous if both the curvature on each side adjacent to the working space and the curvature on each side adjacent to the cavity are designed to be opposite to each other, since this allows for a particularly wide range of adaptation of the molding section to the geometry of the workpiece or molded part to be produced.

[0031] A further embodiment of the device provides that at least one curvature of the shape of the base section, preferably the deviation of the curvature of the shape of the forming section from the curvature of the shape of the edge region of the base section adjacent to the forming section, is generated by plastic deformation of the forming section, in particular by plastic deformation of the shape of the forming section. Thus, the deviation of the curvature, i.e., the amount and / or sign of the curvature, should be generated by pre-plastic deformation of the forming section. As a result, the forming section is permanently adapted to the geometry of the workpiece or part to be produced.

[0032] According to one embodiment of the device, at least one curvature of the shape of the base section, preferably the curvature of the shape of the shaping section, which differs from the curvature of the shape of the edge region of the base section adjacent to the shaping section, extends over a length of at least 6 mm, preferably at least 50 mm, more preferably at least 70 mm, even more preferably at least 100 mm, even more preferably at least 150 mm, even more preferably at least 500 mm, and in particular at least 1000 mm, particularly along the longitudinal and / or transverse extension of the membrane. This provides a shaping section that can be adapted to particularly complex geometries of workpieces or molded articles to be produced and / or particularly large workpieces or molded articles to be produced. In the latter case, for example, changes in the orientation of the membrane can be achieved to a degree that would not be possible without prior plastic deformation of the shaping section, especially in the case of metallic membranes.

[0033] A further embodiment of the device provides that, at least in the open position, the shaping section and / or the base section, in particular the shape of the shaping section and / or the shape of the base section, are at least partially curved about the longitudinal axis of the membrane or an axis parallel to the longitudinal axis of the membrane, about the transverse axis of the membrane or an axis parallel to the transverse axis of the membrane, and / or about the height axis of the membrane or an axis parallel to the height axis of the membrane. This facilitates the production of shaped articles with complex geometries. In the case of the shaping section, this curvature is imprinted on the shaping section by pre-plastic deformation. Preferably, at least in the open position, the shaping section and / or the base section, in particular the shape of the shaping section and / or the shape of the base section, are at least partially curved about at least two of the following axes: the longitudinal axis of the membrane or an axis parallel to the longitudinal axis of the membrane, the transverse axis of the membrane or an axis parallel to the transverse axis of the membrane, and the height axis of the membrane or an axis parallel to the height axis of the membrane. In other words, it is advantageous if, at least in the open position, the shaping section and / or the base section, in particular the shape of the shaping section and / or the shape of the base section, are at least partially curved about at least two axes extending perpendicular to one another. This provides an at least partially doubly curved membrane. This makes it easier to produce shaped articles with complex geometries, in particular doubly curved. It is advantageously provided that the shaping section, preferably the shape of the shaping section, is at least partially curved about at least two axes extending perpendicular to one another, preferably by pre-plastic deformation of the shaping section relative to the base section.

[0034] According to one embodiment of the device, at least in the open position, the molding section is at least partially spaced from the base section, particularly the edge region of the base section adjacent to the molding section, in the direction of the cavity and / or the direction of the working space, at least partially at a predetermined distance, substantially perpendicular to the surface of the edge region of the base section adjacent to the molding section, in the direction of the cavity and / or the working space, this distance being at least equal to the thickness of the film. This provides a molding section that can be adapted to the complex geometry of the workpiece or molded part to be produced. In particular, the molding section provides sufficient space for the protrusion of the workpiece or the molded part to be produced from this workpiece, even in the open position and while pressure and / or temperature are being applied to the workpiece. Furthermore, the molding section designed in this way can be positioned sufficiently close to the recess of the workpiece or the molded part to be produced, thereby achieving uniform contact of the molding section. For example, a corresponding distance in the direction of the cavity would result in a larger cavity volume. This is because, to achieve a sufficient distance between the molding section and the press die, the distance between the membrane and the press die is generally increased throughout. This results in higher acquisition costs, higher operating costs, a higher risk of leaks, and increased temperature control degradation. However, when considering the same overall process, the molding section has the advantage of achieving a similar degree of uniformity in the pressure distribution acting during the pressing process. Advantageously, at least in the open position, a distance exists between the side of the molding section adjacent to the cavity and the side of the base section adjacent to the cavity and / or between the side of the molding section adjacent to the working space and the side of the base section adjacent to the working space. Advantageously, the distance may be at least 6 mm, preferably at least 15 mm, more preferably at least 50 mm, in particular at least 72 mm, and more preferably at least 1000 mm. Alternatively or additionally, the distance may be at least 1.25 times, preferably at least 1.41 times, even more preferably at least 7 times, even more preferably at least 25 times, even more preferably at least 50 times, and in particular at least 100 times the membrane thickness.Advantageously, the forming section may be spaced a predetermined distance from the base section in the direction of the height axis.

[0035] A further embodiment of the device provides that, at least in the open position, the shaping section extends at an incline at least partially relative to the base section, in particular along the longitudinal and / or lateral extension of the membrane, and preferably there is an angle of at least partially at least 90°, preferably at least 100°, in particular at least 120° and / or an angle of at most 180°, preferably at most 160°, in particular at most 145° between the shaping section and the base section, thereby providing a membrane with a change in size in the direction that would not be possible without prior plastic deformation of the shaping section, in particular in the case of a metallic membrane.

[0036] According to one embodiment of the device, it is provided that the forming section extends, in particular along the longitudinal and / or transverse extension of the membrane, by at least 6 mm, preferably at least 50 mm, more preferably at least 70 mm, even more preferably at least 100 mm, even more preferably at least 150 mm, even more preferably at least 500 mm, in particular at least 1000 mm, thereby providing a sufficiently large forming section, which is also suitable for workpieces or parts to be produced with larger dimensions and complex geometries.

[0037] A further embodiment of the device provides that the film thickness of the forming section differs from the film thickness of the base section, in particular the film thickness of the edge region of the base section adjacent to the forming section, by at most 40%, preferably at most 25%, more preferably at most 15%, in particular at most 10%, and even more particularly at most 5%. This provides a film with a particularly uniform film thickness. In this case, the pre-plastic deformation of the forming section only slightly affects the film thickness of the forming section. The film thickness deviation is advantageously present substantially along the entire forming section. Advantageously, both the forming section and the base section, in particular the edge region of the base section adjacent to the forming section, have substantially the same film thickness.

[0038] One embodiment of the device provides that the membrane, particularly the base section and / or the molding section, at least partially has a surface structure, preferably arranged on the side of the membrane adjacent to the working space, particularly on the side of the base section and / or the molding section. This allows the structure to be imprinted onto the workpiece or molded part to be produced. Advantageously, the surface structure may have a mushroom-like, honeycomb-like, groove-like, and / or finger-like surface structure in the μm or mm range. This preferably means that the extension of the surface structure, i.e., the height or depth of the protrusions or recesses of the surface structure, is 0.05 μm to 5 mm + / - 10%. It is particularly preferred that the height or depth of the protrusions or recesses of the surface structure is 0.5 μm to 500 μm + / - 10%. Alternatively or additionally, it may be provided that the surface structure has a regular pattern and / or a shark skin design. Preferably, the surface structure has multiple protrusions and / or depressions rather than a single protrusion or depression. These protrusions and / or depressions are preferably arranged in a regular pattern, rather than randomly distributed across the membrane. In particular, it is envisaged that the surface structure of the membrane has translational symmetry, i.e., a regularly repeating pattern. Preferably, the surface structure is a honeycomb-shaped surface structure, whereby hexagonal protrusions and / or depressions fill the surface with translational symmetry. Finger- or mushroom-shaped protrusions and / or depressions are further preferred, and the pattern of protrusions and / or depressions may be described by one of the five two-dimensional Bravais lattices. The finger- or mushroom-shaped structures of the membrane form an oblique, square, rectangular, hexagonal face-centered, or rectangular face-centered lattice. The surface structure of the membrane also preferably comprises hill-like protrusions with sharply pointed depressions. The membrane is preferably designed so that the surface structure corresponds to the depressions or indentations of riblets, also known as sharkskin.

[0039] A further embodiment of the apparatus is characterized in that the surface of the membrane, in particular the surface of the base section and / or the molding section, preferably on the side of the membrane facing the working space, at least partially has an average surface roughness of less than 63 μm, preferably less than 12 μm, more preferably 0.1 μm to 10 μm, in particular 0.1 μm to 3 μm, which provides a membrane with a particularly smooth surface, which in turn results in a particularly smooth surface for the molded article to be produced.

[0040] According to one embodiment of the device, it is provided that the membrane is at least partially arranged between the first press die and the second press die, and / or the first press die and / or the second press die are / is connected to the membrane, whereby connecting the membrane to one of the press dies provides a defined assembly of the membrane.

[0041] One embodiment of the device provides that the cavity is sealed by at least one seal, at least in the closed position, through which a sealing force can be applied to the membrane, preferably movable relative to the seal. The corresponding seal structurally prevents the working medium from leaking out of the cavity. Because the membrane is movable relative to the seal, changes in the membrane's length, particularly due to thermal expansion or contraction, do not result in excessive stress on the membrane or uneven contact with the workpiece or molded part to be produced. Furthermore, the mobility of the membrane relative to the seal simplifies the application of pretension to the membrane, since the pretension can be applied to the membrane outside the area sealed by the seal. Advantageously, the device includes at least one device for varying the sealing force of the seal. In this way, a particularly tight seal of the cavity can be achieved.

[0042] A further embodiment of the apparatus is characterized in that the first and second press dies are movable relative to each other along a movement axis, and the first and / or second press dies have a first and second press plane, with the first and second press planes of each press die being spaced apart from each other in the direction of the movement axis. The production of parts with more complex geometries is further simplified by appropriately spaced press planes, since this allows the shape of the press die to be adapted to the geometry of the workpiece or part to be produced, thereby allowing for more uniform application of pressure and / or temperature. Advantageously, the movement axis extends horizontally or vertically. Preferably, the movement axis extends substantially through the center of the first and / or second press dies. Alternatively or additionally, the movement axis extends substantially through the center of the working space.

[0043] The shape of the first and / or second press mold, in particular the first and / or second press plane of the first and / or second press mold, corresponds to the shape of the membrane at least on the side adjacent to the working space and / or cavity, preferably to the shape of the molding section on the side adjacent to the working space and / or cavity.

[0044] One embodiment of the device comprises at least one device for varying the pretension of the membrane, which has the advantage that the membrane is in uniform contact with the workpiece, especially before or when the application of temperature and pressure to the workpiece is initiated. The device for varying the pretension of the membrane can be realized, for example, by a spring with an adjustable spring deflection or an adjustable pretension.

[0045] The problem stated at the beginning is also solved by a system for producing molded articles, in particular from fiber composite materials, which system comprises a workpiece and a device for producing molded articles according to one of claims 1 to 21.

[0046] According to one embodiment of the system, it is provided that the shape of the forming section of the device for producing a molded part is at least partially adapted to the shape of the workpiece by plastic deformation at least in the open position. This allows the membrane, particularly in the case of a metallic membrane, to be uniformly contacted with the workpiece or molded part, particularly in the case of a workpiece or molded part having a complex geometry, and preferably the shape of the forming section is at least partially adapted to the shape of the workpiece at least in the open position by pre-plastic deformation of the forming section.

[0047] The object stated at the outset is also achieved by a method for producing molded articles, in particular from fiber composite materials, comprising the steps of a) providing a workpiece, b) providing an apparatus for producing molded articles as claimed in any one of claims 1 to 21, and c) applying pressure and / or temperature to the workpiece by means of the apparatus for producing molded articles. The method advantageously further comprises the step of b1) inserting the workpiece into the apparatus for producing molded articles. Preferably, the workpiece is inserted into the working space in step b1). Furthermore, in step b1), the press tool is advantageously in an open position. The method preferably also comprises the step of b2) moving the first press tool and the second press tool from the open position to the closed position. Steps b1) and / or b2) are preferably performed after steps a) and / or b). Alternatively or additionally, steps b1) and / or b2) are preferably performed before step c). Furthermore, step b1) is preferably performed before step b2).

[0048] According to one embodiment of the method, it is provided that in step b), the shape of the forming section of the device for producing a molded article is at least partially adapted to the shape of the workpiece by plastic deformation, at least in the open position. In this way, uniform contact of the membrane with the workpiece or molded article, particularly in the case of workpieces or molded articles to be produced having complex geometries, can be achieved, particularly in the case of metallic membranes. Preferably, the shape of the forming section is at least partially adapted to the shape of the workpiece, at least in the open position, by pre-plastic deformation of the forming section.

[0049] The invention will now be explained in more detail with reference to the drawings, which show only preferred embodiments. [Brief explanation of the drawings]

[0050] [Figure 1] 1 is a cross-sectional view of a first embodiment of an apparatus for producing a molded article, the apparatus having a press die in an open position. [Figure 2] 2 is a diagram of the apparatus shown in FIG. 1 with a workpiece inserted into the workspace of the apparatus and with the press die of the apparatus in an open position. [Figure 3] 2 is a diagram of the apparatus shown in FIG. 1 with a workpiece inserted into the workspace of the apparatus and with the press die of the apparatus in a closed position. [Figure 4] FIG. 1 is a cross-sectional view of a second embodiment of an apparatus for producing a molded article, the apparatus comprising two membranes, and the press die of the apparatus in the open position. [Figure 5] FIG. 10 is a cross-sectional view of a third embodiment of an apparatus for producing a molded article, with the press die of the apparatus in an open position. [Figure 6] 6 shows the apparatus of FIG. 5 with the membrane curved about at least two axes extending perpendicular to one another and with the press die of the apparatus in an open position. [Figure 7A]FIG. 2 shows a part of the membrane of an apparatus for producing a molded article, provided with a first surface structure and the resulting structuring imparted to the molded article. [Figure 7B] FIG. 2 shows a part of the membrane of an apparatus for producing a molded article, provided with a second surface structure and the resulting structuring imparted to the molded article.

[0051] 1 shows a first embodiment of an apparatus 1 for producing molded parts in a cross-sectional view, with the press dies 2, 3 of the apparatus in the open position, and no workpieces have yet been inserted into the apparatus.

[0052] The apparatus 1 comprises an upper first press die 2 and a lower second press die 3. The two press dies 2, 3 may be moved relative to one another, for example in the vertical direction (as indicated by the arrows in Figure 1), between an open position and a closed position. In the illustrated configuration, it is sufficient that only one press die of the two press dies 2, 3, in particular the first press die 2, is movably mounted.

[0053] Furthermore, the apparatus 1 includes a membrane 4 connected to the first press die 2 in this embodiment. Alternatively to the embodiment shown in FIG. 1, the membrane 4 may be connected to a second press die 3, for example. A cavity 5 for a working medium, e.g., oil, is formed between the membrane 4 and the first press die 2. The membrane 4 is made of metal and preferably has a thickness in the range of 0.05 mm to 4.0 mm. The cavity 5 may be filled with the working medium via a passage 6. Both the first press die 2 and the second press die 3 are provided with holes 7 through which a heating medium and / or a cooling medium can pass. Alternatively or additionally, the first press die 2 and / or the second press die 3 may include a heating element, in particular an insertable heating plate, which may be inserted into the respective press die 2, 3.

[0054] In the design of the device 1 shown in Figure 1, a working space 8 is formed between the two press dies 2, 3, in this case in particular between the membrane 4 and the second press die 3. A workpiece (not shown in Figure 1) can be inserted into the working space. The two press dies 2, 3 preferably have guides 9, which can be formed, for example, by a protrusion 9A and a recess 9B, where the protrusion 9A can be provided on the second press die 3 and the recess 9B can be provided on the first press die 2.

[0055] The membrane 4 is connected to the first press die 2 as follows. The first press die 2 has a peripheral edge element 10 connected to it, in particular by screwing (the screw connection is not shown in FIG. 1 ). A gap 11 is formed between the first press die 2 and its edge element 10, through which the membrane 4 is guided. The gap 11 opens into a cavity 12, in which a clamping device 13 is provided for clamping the membrane 4 therein. The clamping device 13 is connected to a tie rod 14, which leads out of the first press die 2 and the edge element 10 through the opening and is pressed outward by a spring 15 supported on the outside, thereby providing a pretension to the membrane 4. The spring 15 is part of a device for varying the pretension of the membrane 4.

[0056] To seal the cavity 5, a seal 16 is provided in the gap 11, which seal 16 allows the membrane 4 to be displaced. The seal 16 presses against the membrane 4 with a sealing force. In order to vary this sealing force, in this case a device 17 for varying the sealing force of the seal 16 is provided.

[0057] In the present view shown in Figure 1, the lateral axis Q of the membrane 4 extends from left to right, the longitudinal axis L of the membrane 4 extends into the image plane of Figure 1, and the height axis H of the membrane 4 extends from bottom to top. The axes are shown accordingly in Figure 1 and in the subsequent figures. Thus, in Figure 1, the lateral extension of the membrane 4 extends substantially from left to right or right to left, and the longitudinal extension of the membrane 4 extends substantially into or out of the image plane of Figure 1.

[0058] The membrane 4 has at least one elastically deformable base section G, G' for contacting the workpiece, in particular the molded part to be produced, and at least one pre-plastically deformed forming section F for contacting the workpiece, in particular the molded part to be produced. In the embodiment of the apparatus 1 shown in the drawings, a first base section G is provided along the transverse extension of the membrane 4, a forming section F is provided adjacent to the first base section G, and a second base section G' is provided adjacent to the forming section F. This forming section F is pre-plastically deformed relative to the base sections G, G'. As a result of the pre-plastic deformation, the forming section F is given a shape different from that of at least one of the base sections G, G', preferably both base sections G, G'. In this embodiment, this forming section F does not extend parallel to the base sections G, G', but extends partially obliquely relative to the base sections G, G'. The pre-plastic deformation of the forming section F enables workpieces with complex geometries to be processed by the apparatus 1 and molded parts with complex geometries to be produced. In particular, in the case of a device 1 in which the membrane 4 is made of metal, only a certain degree of elastic deformation of the membrane 4 is possible in order to follow the shape of a workpiece having a complex geometry or of a molded part to be produced.

[0059] The pre-plastic deformation of the forming section F makes the base sections G, G' more elastically deformable than the forming section F. The base sections G, G' can be deformed more strongly in the direction of the working space 8 by elastic deformation, in particular by linear elastic deformation, compared to the forming section F. Nevertheless, the forming section F can still be elastically deformed at least to some extent.

[0060] In this case, the shaping section F has bending points K, K' in each of its outer regions along the transverse extension of the membrane 4. The bending points K, K' are generated by a pre-plastic deformation of the shaping section F relative to the base sections G, G'. In the region of the bending points K, K', the shape of the shaping section F has a curvature that differs from the shape of the base sections G, G', both in terms of the amount of curvature and the sign of the curvature. Therefore, the base sections G, G', and in particular the edge regions of each base section G, G' adjacent to the shaping section, have a curvature of zero, since the base sections G, G', respectively, are straight. On the other hand, the shaping section F has a curvature in the region of the bending points K, K' that is not equal to zero, and thus a deviation in curvature relative to the base sections G, G'.

[0061] In the configuration shown, there are deviations in curvature and the presence of opposite curvatures, both between the curvature of the shape of the molding section F on the side of the molding section F adjacent to the cavity 5 and the curvature of the shape of the base sections G, G' on the side of the base sections G, G' adjacent to the cavity 5, preferably in any case the curvature of the shape of the edge regions of the base sections G, G' adjacent to the molding section F, and between the curvature of the shape of the molding section F on the side of the molding section F adjacent to the working space 8 and the curvature of the shape of the base sections G, G' on the side of the base sections G, G' adjacent to the working space 8, preferably in any case the curvature of the shape of the edge regions of the base sections G, G' adjacent to the molding section F.

[0062] In this case, the molding section F extends partially inclined relative to the base sections G, G', respectively, in the illustrated configuration, in particular at an angle of 45°. In this case, in particular on the side of the molding section F adjacent to the cavity 5 and on the side of the molding section F adjacent to the working space 8, the molding section F is spaced apart at least partially from the first base section G, in particular from the edge region of the first base section G adjacent to the molding section F, in the direction of the cavity 5, in particular substantially perpendicular to the surface of the edge region, and from the edge region of the second base section G', in particular from the edge region of the second base section G' adjacent to the molding section F, in the direction of the working space 8, in particular substantially perpendicular to the surface of the edge region, each by a distance which corresponds at least to the thickness of the film.

[0063] The deviation in curvature between the shape of the forming section F and the shape of the base sections G, G' is generated in this case by a plastic deformation, in particular a pre-plastic deformation, of the forming section F. Despite this plastic or pre-plastic deformation, the thickness of the film of the forming section F differs from the thickness of the film of the base sections G, G' by no more than 40%.

[0064] Figure 2 shows the apparatus of Figure 1 with a workpiece 18 inserted into the working space 8 of the apparatus 1 and with the press dies 2, 3 of the apparatus 1 in the open position. The areas of the apparatus 1 already mentioned above are marked with corresponding reference numerals in Figure 2. The difference from Figure 1 is that the workpiece 18 has been inserted into the working space 8.

[0065] FIG. 3 shows the apparatus 1 of FIG. 1 with a workpiece 18 inserted into the working space 8 of the apparatus 1 and the press dies 2 and 3 of the apparatus 1 in the closed position. The previously mentioned areas of the apparatus 1 are labeled with corresponding reference numerals in FIG. 3 . The apparatus 1 is closed, and the two press dies 2 and 3 are moved toward each other, resulting in the closed position. In the closed position shown in FIG. 3 , pressure and temperature are applied to the workpiece 18. Pressure is applied by supplying a working medium, e.g., oil, into the cavity 5 through the passage 6, which presses the membrane 4 toward the workpiece 18. Temperature can be applied in various ways. One possibility is to heat the working medium supplied into the cavity 5 through the passage 6, thereby transferring heat from the working medium in the cavity 5 through the membrane 4 to the workpiece 18. Conversely, the working medium can be cooled to cool the workpiece 18. Alternatively or additionally, it may be provided that a heating medium and / or a cooling medium flows through the holes 7, whereby the two press dies 2, 3 may be heated or cooled, and subsequently the workpiece 18 may be heated or cooled.

[0066] FIG. 4 shows a cross-sectional view of a second embodiment of an apparatus 1 for producing molded articles, with the apparatus 1 equipped with two membranes 4 and with the press dies 2, 3 of the apparatus 1 in the open position. Furthermore, a workpiece 18 has been inserted into the working space 8 of the apparatus 1. The second embodiment of the apparatus 1 shown in FIG. 4 differs substantially from the first embodiment of the apparatus 1 previously shown in FIGS. 1 to 3 in that a membrane 4′ is also provided on the second press die 3. Identical components of the embodiments are again provided with the same reference numerals. Essentially only the differences between the embodiments will be explained in more detail below.

[0067] In the apparatus 1 of FIG. 4, membranes 4, 4' are provided on both the first press die 2 and the second press die 3. The first press die 2 and the first membrane 4 connected to it are designed as shown in FIGS. 1 to 3. In this embodiment, the second press die 3 also includes a pre-plastically deformed second membrane 4'. The first membrane 4 and the second membrane 4' are designed identically to each other. Thus, the second membrane 4' also has a pre-plastically deformed forming section F and two base sections G, G', where the shape of the forming section F has a curvature that is at least partially different from the shapes of the base sections G, G'. By providing two membranes 4, 4', pressure and temperature can be simultaneously applied to the workpiece 18 from two sides, in this case, from above and below. As in the first embodiment of the apparatus 1, the press dies 2, 3 can be moved relative to each other from an open position to a closed position (as indicated by the arrows in FIG. 4). A working space 8 is formed between the first press die 2 and the second press die 3, in particular between the first membrane 4 and the second membrane 4'.

[0068] In Figure 5, a third embodiment of the apparatus 1 for producing molded articles is shown in a cross-sectional view, with the press dies 2, 3 of the apparatus 1 in the open position. Furthermore, a workpiece 18 has been inserted into the working space 8 of the apparatus 1. The third embodiment of the apparatus 1 shown in Figure 5 differs from the first embodiment of the apparatus 1 shown in Figures 1 to 3 essentially in the shape of the press dies 2, 3 and in the shape of the membrane 4. Identical components between the embodiments are also provided with the same reference numerals. In the following, essentially only the differences between the embodiments will be explained in more detail.

[0069] In a third embodiment of the apparatus 1, the two press dies 2, 3 have a substantially arcuate shape. Furthermore, the sections of the membrane 4 also have a substantially arcuate shape, particularly in the region of the base sections G, G'. The base sections G, G' have a substantially continuous curvature due to elastic deformation, in this case caused by the force of gravity. The pre-plastically deformed forming section F has a substantially S-shaped shape due to pre-plastic deformation, particularly with respect to the base sections G, G'. The shape of the forming section F is adapted to the complex geometry of the workpiece 18 arranged in the working space 8 of the apparatus 1 and the molded part to be produced from this workpiece 18. The curvature of the shape of the forming section F differs at least partially from the curvature of the edge regions of each base section G, G' adjacent to the forming section F along the transverse extension of the membrane 4. Furthermore, the curvature of the shape of the forming section F along the transverse extension of the membrane 4 is at least partially opposite to the curvature of the shape of the edge regions of each base section G, G' adjacent to the forming section F. The curvature of the shape of the forming section F in the region of the second bending point K' therefore runs in the opposite direction to the curvature of the shape of the base sections G, G'.

[0070] Figure 6 shows the apparatus 1 according to Figure 5, in which the membrane 4 is bent about at least two axes extending perpendicular to one another and the press dies 2, 3 of the apparatus 1 are in the open position. Furthermore, a workpiece 18 has been inserted into the working space 8 of the apparatus 1. Figure 6 differs from Figure 5 essentially only in the shape of the membrane 4. Therefore, identical components are also provided with the same reference numerals. In the following, essentially only the differences will be described.

[0071] Like FIG. 5, the membrane 4 shown in FIG. 6 has a pre-plastically deformed forming section F and two elastically deformable base sections G, G'. However, the membrane 4 shown in FIG. 6 is also curved about at least two mutually perpendicular axes. In particular, the membrane 4 has a curvature about a transverse axis Q and a curvature about a longitudinal axis L for the portion of the membrane 4 extending in the imaginary plane of FIG. 6. In this membrane 4, the shape of the forming section F is curved about the transverse axis Q and the longitudinal axis L, and the shape of the base sections G, G' is also at least partially curved about the transverse axis Q and the longitudinal axis L. This makes it possible to produce molded parts with extremely complex geometries, such as a doubly curved aircraft cockpit.

[0072] FIG. 7A shows a portion of a membrane 4 of an apparatus 1 for producing molded articles, which includes a first surface structure 20, and the resulting structure 21 on a molded article 19. The molded article 19 is produced from a workpiece 18. In FIG. 7A, the structure 21 is designed like a riblet structure or shark skin. The riblet structure provides the molded article 19 with low flow resistance. The riblet structure includes regularly spaced ribs 22 with sharp peaks, whereby the peaks are spaced apart by 50 μm in this embodiment. The height of the ribs 22, or the depth of the grooves formed by the spaced ribs 22, is 70 μm in this embodiment. The riblet structure on the molded article 19 is imprinted into the workpiece 18 and thus the molded article 19 by the surface structure 20 of the membrane 4, and the surface structure 20 corresponds to the recesses of the riblet structure.

[0073] 7B shows a portion of the membrane 4 of the device 1 for producing molded articles, which is provided with a second surface structure 20′, and the resulting structure 21′ imparted to the molded article 19. The structure 21′ of the molded article 19 is finger-like and generates a lotus effect, i.e., it allows water to roll off the surface of the molded article 19. The fingers 23 of the finger-like structure have a length of approximately 100 μm, a width of 20 μm, and are spaced 30 μm apart. [Explanation of symbols]

[0074] 1. Equipment for producing molded articles 2. First press die 3 Second press die 4, 4' membrane 5 hollow 6 aisles 7 holes 8. Workspace 9 Guide 9A Convex part 9B Recess 10 Edge Elements 11 Gap 12 Cavity 13 Fastening device 14 tie rod 15 Spring 16 Seals 17 Device for varying the sealing force 18 workpieces 19 Molded products 20, 20' surface structure 21, 21' structured part 22 Ribs 23 Finger F Molding category G, G' Basic classification H Height axis K, K', K'' bending point L Longitudinal axis Q Lateral axis

Claims

1. An apparatus (1) for producing moulded articles, in particular from fibre composite materials, comprising: a first press die (2), a second press tool (3), at least one membrane (4, 4') for contacting the workpiece (18); Equipped with - the first press die (2) and the second press die (3) are movable relative to each other between an open position and a closed position; a cavity (5) for a working medium is formed between the membrane (4, 4') and the first pressing die (2) and / or the second pressing die (3), at least in the closed position; a working space (8) for accommodating the workpiece (18) is formed between the first press die (2) and the second press die (3), in particular between the membrane (3) and the first press die (2) and / or the second press die (3); said membranes (4, 4') have a thickness, a longitudinal extension and a lateral extension; In the apparatus (1), The device (1) is characterized in that the membrane (4, 4') has, in particular along the longitudinal and / or lateral extension of the membrane (4, 4'), at least one elastically deformable base section (G, G') for contacting the workpiece (18) and at least one pre-plastically deformed forming section (F) for contacting the workpiece (18).

2. 2. The device (1) according to claim 1, characterized in that, at least in the open position, the shaping section (F) is pre-plastically deformed relative to the base section (G, G'), in particular along the longitudinal and / or lateral extension of the membrane (4, 4').

3. 3. Device (1) according to claim 1 or 2, characterized in that the membranes (4, 4') are made of metal, preferably steel, in particular stainless steel.

4. The device (1) according to any one of claims 1 to 3, characterized in that the base section (G, G') is more elastically deformable than the shaping section (F) and / or the membrane (4, 4'), in particular the base section (G, G'), is deformable by elastic deformation in the direction of the working space (8).

5. 5. The device (1) according to claim 1, characterized in that, at least in the open position, the curvature of the shape of the shaping section (F), in particular along the longitudinal and / or lateral extension of the membrane (4, 4'), is at least partially different from the curvature of at least one of the shape of the base section (G, G'), preferably from the curvature of the shape of an edge region of the base section (G, G') adjacent to the shaping section (F).

6. 6. The device (1) according to claim 5, characterized in that, at least in the open position, the curvature of the shape of the forming section (F) on its side adjacent to the cavity (5) is at least partially different from the at least one curvature of the shape of the base section (G, G'), preferably the curvature of the shape of the edge region of the base section (G, G') adjacent to the forming section (F) on its side adjacent to the cavity (5), and / or the curvature of the shape of the forming section (F) on its side adjacent to the working space (8) is at least partially different from the at least one curvature of the shape of the base section (G, G'), preferably the curvature of the shape of the edge region of the base section (G, G') adjacent to the forming section (F) on its side adjacent to the working space (8).

7. 7. The device (1) according to any one of claims 1 to 6, characterized in that, at least in the open position, the curvature of the shape of the shaping section (F), in particular along the longitudinal and / or lateral extension of the membrane (4, 4'), is designed at least partially opposite to the curvature of the shape of at least one of the base sections (G, G'), preferably the curvature of the shape of the edge region of the base section (G, G') adjacent to the shaping section (F).

8. 8. The device (1) according to claim 7, characterized in that, at least in the open position, the curvature of the shape of the forming section (F) on its side adjacent to the cavity (5) is at least partially opposite to the curvature of the shape of the at least one base section (G, G'), preferably the curvature of the shape of the edge region of the base section (G, G') adjacent to the forming section (F) on its side adjacent to the cavity (5), and / or the curvature of the shape of the forming section (F) on its side adjacent to the working space (8) is at least partially opposite to the curvature of the shape of the at least one base section (G, G'), preferably the curvature of the shape of the edge region of the base section (G, G') adjacent to the forming section (F) on its side adjacent to the working space (8).

9. The device (1) according to any one of claims 5 to 8, characterized in that the deviation of the at least one curvature of the shape of the base section (G, G'), preferably the curvature of the shape of the shaping section (F) from the curvature of the shape of the edge region of the base section (G, G') adjacent to the shaping section (F), is generated by plastic deformation of the shaping section (F), in particular by plastic deformation of the shape of the shaping section (F).

10. The device (1) according to any one of claims 5 to 9, characterized in that the at least one curvature of the shape of the base section (G, G'), preferably the curvature of the shape of the shaping section (F), which differs from the curvature of the shape of the edge region of the base section (G, G') adjacent to the shaping section (F), extends over a length of at least 6 mm, preferably at least 50 mm, more preferably at least 70 mm, even more preferably at least 100 mm, even more preferably at least 150 mm, even more preferably at least 500 mm, in particular at least 1000 mm, in particular along the longitudinal and / or lateral extension of the membrane (4, 4').

11. 11. The device (1) according to any one of claims 1 to 10, characterized in that, at least in the open position, the shaping section (F) and / or the base section (G, G'), in particular the shape of the shaping section (F) and / or the shape of the base section (G, G'), are at least partially bendable about a longitudinal axis (L) of the membrane (4, 4') or an axis parallel to the longitudinal axis (L) of the membrane (4, 4'), about a transverse axis (Q) of the membrane (4, 4') or an axis parallel to the transverse axis (Q) of the membrane (4, 4'), and / or about a height axis (H) of the membrane (4, 4') or an axis parallel to the height axis (H) of the membrane (4, 4').

12. 12. The device (1) according to claim 1, characterized in that, at least in the open position, the forming section (F) is at least partially spaced apart from the base section (G, G'), in particular from an edge region of the base section (G, G') adjacent to the forming section (F), in particular on the side of the forming section (F) adjacent to the cavity (5) and / or on the side of the forming section (F) adjacent to the working space (8), by a predetermined distance in the direction of the cavity (5) and / or in the direction of the working space (8), in particular substantially perpendicular to the surface of the edge region of the base section (G, G') adjacent to the forming section (F), said distance corresponding at least to the film thickness.

13. 13. The device (1) according to any one of claims 1 to 12, characterized in that, at least in the open position, the shaping section (F) extends at least partially obliquely relative to the base section (G, G'), in particular along the longitudinal and / or lateral extension of the membrane (4, 4'), preferably such that there is at least partially an angle of at least 90°, preferably at least 100°, in particular at least 120° and / or an angle of at most 180°, preferably at most 160°, in particular at most 145° between the shaping section (F) and the base section (G, G').

14. The device (1) according to any one of claims 1 to 13, characterized in that the shaping section (F) extends at least 6 mm, preferably at least 50 mm, more preferably at least 70 mm, even more preferably at least 100 mm, even more preferably at least 150 mm, even more preferably at least 500 mm, in particular at least 1000 mm, in particular along the longitudinal and / or transverse extension of the membrane (4, 4').

15. 15. The device (1) according to any one of claims 1 to 14, characterized in that the thickness of the shaping section (F) differs from the thickness of the base section (G, G'), in particular from the thickness of the edge region of the base section (G, G') adjacent to the shaping section (F) by at most 40%, preferably at most 25%, more preferably at most 15%, in particular at most 10%, more particularly at most 5%.

16. 16. The device (1) according to any one of claims 1 to 15, characterized in that the membrane (4, 4'), in particular the base section (G, G') and / or the forming section (F) at least partially has a surface structure (20, 20'), preferably the surface structure (20, 20') being arranged on a side of the membrane (4, 4') adjacent to the working space (8), in particular on the side of the base section (G, G') and / or the forming section (F).

17. 17. Apparatus (1) according to any one of claims 1 to 16, characterized in that the surfaces of the membranes (4, 4'), in particular the surfaces of the base sections (G, G') and / or the shaping sections (F), preferably on the side of the membranes (4, 4') facing the working space (8), at least partially have an average surface roughness of less than 63 μm, preferably less than 12 μm, more preferably between 0.1 μm and 10 μm, in particular between 0.1 μm and 3 μm.

18. 18. The device (1) according to any one of claims 1 to 17, characterized in that the membrane (4, 4') is at least partially arranged between the first press die (2) and the second press die (3) and / or the first press die (2) and / or the second press die (3) are connected to the membrane (4, 4').

19. The device (1) according to any one of claims 1 to 18, characterized in that the cavity (5) is sealed, at least in the closed position, by at least one seal (16) through which a sealing force can be applied to the membranes (4, 4'), preferably the membranes (4, 4') being movable relative to the seal (16).

20. 20. The apparatus (1) according to any one of claims 1 to 19, characterized in that the first press die (2) and the second press die (3) are movable relative to each other along a movement axis, the first press die (2) and / or the second press die (3) having a first press plane and a second press plane, the first press plane and the second press plane of each press die (2, 3) being spaced apart from each other in the direction of the movement axis.

21. Device (1) according to any one of the preceding claims, characterized by at least one device for varying the pretension of the membranes (4, 4').

22. A system for producing moulded articles (19), in particular from fibre composite materials, comprising: a workpiece (18), - a device (1) for producing moulded articles according to any one of claims 1 to 21; A system comprising:

23. 23. The system according to claim 22, characterized in that in the device (1) for producing a molded part, the shape of the molding section (F) is at least partially adapted to the shape of the workpiece (18) by plastic deformation, at least in the open position.

24. A method for producing a moulded article (19), in particular from a fibre composite material, comprising: a) providing a workpiece (18); b) providing a device (1) for producing a moulded article according to any one of claims 1 to 21; c) applying pressure and / or temperature to the workpiece (18) by means of the device (1) to produce a moulded article; A method comprising:

25. 25. The method according to claim 24, characterized in that in the device (1) for producing the molded part prepared in step b), the shape of the molding section (F) is at least partially adapted to the shape of the workpiece (18) by plastic deformation, at least in the open position.

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