COMPOSITE MATERIAL

Abstract

Composite materials used as fire protection panels.

Claims

1-15. (canceled)

16. A composite material comprising fibres and graphite foil for fire protection and/or heat dissipation panel.

17. The composite material according to claim 16, wherein the fibres and the graphite foil are each arranged as at least one layer on top of one another.

18. The composite material according to claim 16, wherein the fibres are embedded in a matrix.

19. The composite material according to claim 18, wherein the matrix is made of plastics material.

20. The composite material according to claim 19, wherein the plastics material is selected from the group consisting of thermoplastics, elastomers, duromers or mixtures thereof.

21. The composite material according to either claim 16, wherein the fibres are selected from the group consisting of carbon fibres, glass fibres, aramid fibres, metal fibres, ceramic fibres, natural fibres and basalt fibres or mixtures thereof.

22. The composite material according to claim 16, wherein the fibres are present in the form of short fibres, long fibres, continuous fibres, rovings, woven fabrics, scrims, nonwoven fabrics or mixtures thereof.

23. The composite material according to claim 16, wherein the graphite foil has a thickness of 0.15 to 2 mm.

24. The composite material according to claim 16, wherein the graphite foil has holes.

25. The composite material according to claim 24, wherein at least a some of the holes are at least partially filled with resin.

26. The composite material according to claim 16, wherein the graphite foil has a protective film.

27. The composite material according to claim 26, wherein the protective film is selected from the group consisting of plastics material, resins or ceramics.

28. The composite material according to claim 26, wherein the thickness of the protective film is less than 1 mm.

29. The composite material according to claim 16, wherein active or passive cooling is applied to the edge regions of the composite material.

30. The composite material according to claim 16, wherein the fire protection panel is a fire protection door, the walls of an insulated transport container or a battery housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the following, purely by way of example, the present invention is described by way of advantageous embodiments and with reference to the accompanying drawings.

[0036] FIG. 1a is a perspective view of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3).

[0037] FIG. 1b is a perspective view of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3).

[0038] FIG. 1c is a cross section of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3).

[0039] FIG. 1d is a cross section of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3).

[0040] FIG. 2a is a perspective view of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3) and in each case a protective film (5).

[0041] FIG. 2b is a perspective view of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3) and in each case a protective film (5).

[0042] FIG. 2c is a cross section of a composite material (1) having graphite foil (2) or perforated graphite foil (3) and in each case a protective film (5).

[0043] FIG. 2d is a cross section of a composite material (1) having graphite foil (2) or perforated graphite foil (3) and in each case a protective film (5).

[0044] FIG. 3a is a perspective view of a composite material (1), where the perforated graphite foil (3) is located between two layers of fibres and matrix.

[0045] FIG. 3b is a cross section of a composite material (1) where the perforated graphite foil (3) is located between two layers of fibres and matrix.

DETAILED DESCRIPTION

[0046] FIG. 1a is a perspective view of a composite material (1). A graphite foil (2) is applied to the layer made of fibres and a matrix (4). The layer made of fibres and a matrix (4) forms a form-fit connection with the graphite foil (2).

[0047] FIG. 1b is a perspective view of a composite material (2). A perforated graphite foil (3) is applied to the layer made of fibres and a matrix (4). The layer made of fibres and a matrix (4) forms a form-fit connection with the perforated graphite foil (3).

[0048] FIGS. 1c and d are in each case a cross section of a composite material (1) having a graphite foil (2) or a perforated graphite foil (3).

[0049] FIG. 2a is a perspective view of a composite material (1). A graphite foil (2) is applied to the layer made of fibres and a matrix (4), and a protective film (5) is applied to said graphite foil. The layer made of fibres and a matrix (4) forms a form-fit connection with the graphite foil (2).

[0050] FIG. 2b is a perspective view of a composite material (1). A perforated graphite foil (3) is applied to the layer made of fibres and a matrix (4) and a protective film (5) is applied to said graphite foil. The layer made of fibres and a matrix (4) forms a form-fit connection with the graphite foil (2).

[0051] FIGS. 2c and d are in each case a cross section of a composite material (1) having graphite foil (2) or perforated graphite foil (3) and in each case a protective film (5).

[0052] FIG. 3 is a perspective view of a composite material (1), where the perforated graphite foil (3) is located between two layers of fibres and matrix (4).

[0053] FIG. 3b is a cross section of a composite material (1) where the perforated graphite foil (3) is located between two layers of fibres and matrix.

[0054] The present invention is explained below using embodiments which, however, do not represent any limitation of the invention.

[0055] The production of a medical technology component can be carried out as described below.

Embodiment 1

[0056] In one embodiment, a 2.5 mm thick composite material is fabricated for use as a flame retardant panel. For this purpose, eight layers of an epoxy resin prepreg having unidirectionally oriented carbon fibres and a fibre surface weight of 250 g/m.sup.2 are stacked quasi-isotropically on top of one another in the 0°, 45°, 90°, −45°, −45°, 90°, 45° and 0° directions, whereby “quasi-isotropic” means that approximately the same mechanical properties are produced for the layer made of fibres and a matrix (4) in all directions within the plane. A 0.5 mm thick graphite foil (2) is also added as the top layer. Said graphite foil does not require a separate adhesive for adhesion, but rather adheres due to the material connection that is formed between the resin surface of the layer made of fibres and a matrix (4) and the graphite foil (2) during the curing process. For this curing process, the laid sheet is hardened for 2 h at a temperature of 130° C. under a pressure of 5 bar. This process converts the carbon fibre semi-finished product into a stable carbon fibre reinforced plastics material (CFRP) (layer made of fibres and a matrix (4) and combines this with the graphite foil (2) to form a form-fitting composite material (1). In the application, the graphite foil side faces a potential flame or heat source to achieve the best possible fire protection effect due to the heat distribution within the xy plane and the gas impermeability of the graphite foil (2).

Embodiment 2

[0057] In a further embodiment 2, the procedure is analogous to that of embodiment 1, but a perforated graphite foil (3) is used. This 0.5 mm thick graphite foil (3) was provided, via a perforation process, with holes which are distributed homogeneously at equal intervals over the entire foil. The hole pattern has holes having a diameter of 1.3 mm and a hole spacing of 5.3 mm. This results in an open hole surface of 5.5%. Due to the flowability of the resin system and the applied pressure, resin is able to flow through these holes and thus form mechanically stabilising resin bridges to the comparatively weak perforated graphite foil (3). The internal strength within the graphite foil plane is therefore increased.

Embodiment 3

[0058] In another embodiment, exactly the same structure as in embodiment 2 is used, but in addition, a 0.1 mm thick resin film is applied to the perforated graphite foil (3) as a protective film (5). The curing process is the same as in embodiment 2; the additional resin film ensures that a homogeneous protective film forms on the graphite foil, protecting the soft surface of the graphite foil against mechanical abrasion or scratches.

Embodiment 4

[0059] In another embodiment 4, instead of an epoxy resin prepreg, a thermoplastic tape having carbon fibre reinforcement with polyamide 6 matrix is used as a precursor for the layer made of fibres and a matrix (4). These tapes also have a unidirectional fibre reinforcement having 250 g/m.sup.2 fibre surface weight. The CFRP layer structure is placed in the same way as in the previous embodiments and a graphite foil (2) of thickness 0.5 mm is placed over it. In the subsequent processing step, the layers are consolidated for 20 minutes at 260° C. and under a pressure of 10 bar. The resulting laminate is shaped in a further processing step. For this purpose, the laminate is heated above the glass transition temperature by means of an infrared radiator, so that the thermoplastic matrix becomes mouldable again. By means of a robot arm, the soft structure is transferred into the desired press mould and brought into the desired geometry via a mould counterpart. Under a pressure of 30 bar, the laminate is cooled down again and can be taken out at a laminate temperature of 80° C.

Embodiment 5

[0060] In another embodiment, the graphite foil is sandwiched between two layers of biaxial scrim made of carbon fibres having a basis weight of 290 g/m.sup.2 each with the fibre orientation of +/−45°. The graphite foil having a thermal conductivity of 350 W/(mK) has a thickness of 0.6 mm and thus provides a sufficiently high thermal conductivity capacity for use as a heat dissipating heat dissipation panel. The graphite foil is provided with holes at intervals of 1.5 cm, the diameter of which is 2 mm. Epoxy resin mixed ready for reaction from resin and hardener (resin/hardener ratio of 100:21 parts by mass) at a temperature of 60° C. is applied to each of the two layers of scrim. The graphite foil is inserted between the two resin-coated layers of scrim and the complete stack is pressed into a mould heated to 120° C. for 3 minutes so that the resin impregnates the textiles and then cures. Resin passing through the holes in the foil provides the connection between the two layers of fibres and ensures that the graphite foil is firmly incorporated into the composite sheet. After completion of the pressing process, the manufactured fire protection panel can be removed from the mould.

LIST OF REFERENCE SIGNS

[0061] (1) Composite material [0062] (2) Graphite foil [0063] (3) Perforated graphite foil [0064] (4) Layer fibres and matrix [0065] (5) Protective fil