Fiber reinforced polymer manufacturing
Method of manufacturing a product comprising fiber reinforced polymer material, the method comprising the steps of: providing 10 carbon fibers being embedded in a thermosetting resin, heating 20 the thermosetting resin up to its cure temperature by a current flowing through at least a part of said carbon fibers, letting convert 30 the thermosetting resin to a thermoset polymer. The invention is further directed to a device for performing the method and to a composite sandwich panel structure manufactured according to the method.
1. A method of manufacturing a product ( 300 ) comprising fiber reinforced polymer material, the product ( 300 ) being a composite sandwich panel structure ( 500 , 600 ) comprising a core ( 503 , 603 ) between a first face sheet ( 501 , 601 ) and a second face sheet ( 502 , 602 ), the method comprising the steps of:
providing ( 10 ) carbon fibers being embedded in a thermosetting resin,
heating ( 20 ) the thermosetting resin up to its cure temperature by a current flowing through at least a part of said carbon fibers,
letting convert ( 30 ) the thermosetting resin to a thermoset polymer, wherein at least one of said first face sheet and said second face sheet comprises the carbon fibers embedded in the thermoset polymer.
2. Method according to claim 1 , further comprising the preceding step of arranging said carbon fibers on a surface of a former or in a mold defining a shape of said product.
3. Method according to claim 2 , wherein after heating the thermosetting resin up to its cure temperature, a structure comprising carbon fibers and partially cured resin is removed from said former or said mold.
4. Method according to claim 2 , wherein carbon fibers are pre-impregnated by the thermosetting resin before arranging them on the surface of said former or in said mold.
5. Method according to claim 2 , wherein after arranging the carbon fibers in said mold, thermosetting resin is injected into said mold.
6. Method according to claim 2 , further comprising the step of providing said former or said mold comprising thermally insulating material and/or covering said former or said mold with a multilayer insulation.
7. Method according to claim 6 , wherein the thermally insulating material is one or more of wood, cork, ceramics, glass, mineral wool, or polymer foam.
8. Method according to claim 1 , further comprising the preceding step of bringing distant sections of said part of carbon fibers into electrically conducting contact with electrodes of a power supply.
9. Method according to claim 8 , wherein said electrodes are clamped to said carbon fibers.
10. Method according to claim 9 , wherein said electrodes are of a solid bar construction.
11. Method according to claim 8 , wherein said electrodes have the form of metallic filaments being woven into a fabric comprising said carbon fibers.
12. Method according to claim 11 , wherein the metallic filaments are arranged in orthogonal direction to said carbon fibers.
13. Method according to claim 8 , wherein said carbon fibers are arranged in multiple plies and the plies are connected in parallel to the power supply.
14. Method according to claim 1 , wherein the carbon fibers are provided in form of a band-shaped fabric comprising carbon fibers at least in a longitudinal direction.
15. Method according to claim 14 for manufacturing a laminate structure, the method comprising the step of arranging said band-shaped fabric parallel to a surface of the laminate structure and covering said surface.
16. Method according to claim 1 , wherein said at least one of said first face sheet and said second face sheet comprises an electrically insulating layer ( 510 , 605 , 607 ) between said carbon fibers and said core and/or between said carbon fibers and an exterior of said structure.
17. Method according to claim 1 , wherein said core ( 503 , 603 ) is electrically non-conductive.
18. Method according to claim 1 , wherein said structure comprises at its surface electrical contact elements ( 606 ), said electrical contact elements being in electrical contact with said carbon fibers and being designed as solid bar constructions.
19. Method according to claim 1 , wherein said structure comprises at its surface electrical contact elements ( 606 ), said electrical contact elements being in electrical contact with said carbon fibers and said electrical contact elements comprising electrically conducting fibers.
20. Method according to claim 1 wherein said structure comprises edge reinforcements built as monolithic construction comprising glass fibers and electrically conducting fibers.
21. Device for performing the method according to claim 1 , comprising
a former or a mold comprising thermally and electrically insulating material,
electrodes for connecting carbon fibers to a power supply, the electrodes being arranged on the former or in the mold.
22. A composite sandwich panel structure ( 500 , 600 ) manufactured according to claim 1 .
23. A composite sandwich panel structure manufactured according to claim 22 , the structure comprising an inner face sheet, a honeycomb structure and an outer face sheet, all of which comprising a thermoset polymer, wherein carbon fibers are arranged to follow a path uniformly covering the inner and/or the outer face sheet.