A winding impregnation structure of an ultra-thin carbon-carbon screen blank

Abstract

The present invention discloses a winding and impregnation structure for an ultra-thin carbon-carbon screen mesh blank, belonging to. The winding and impregnation structure includes an upper pressing plate, a lower pressing plate, a combined winding plate and a triangular gasket. The upper pressing plate and the lower pressing plate both include three different types: a metal pressing plate, a flat graphite pressing plate and a graphite pressing plate with grid grooves, which are respectively used for different procedures of the winding and impregnation molding process. The combined winding plate is placed between the upper pressing plate and the lower pressing plate, and the upper pressing plate, the combined winding plate and the lower pressing plate are fixed and pressed by fixing parts. The triangular gasket is used to be placed on the upper and lower surfaces of the combined winding plate that are not covered by the winding layer. The present invention solves the problem that different procedures in the preparation process of the ultra-thin carbon-carbon screen mesh blank have inconsistent requirements on the surface state of the pressing plate, which easily leads to unevenness of the blank, difficulty in impregnating the preform with asphalt, and difficulty in discharging small molecules during high-temperature treatment.

Description

Technical Field

[0001] The invention relates to a winding and impregnation structure of an ultra-thin carbon-carbon screen blank, belonging to the technical field of engine design. Background Art

[0002] With the gradual advancement of deep space exploration, traditional chemical propulsion systems are increasingly unable to meet the needs of deep space exploration missions. In response to the new situation, long-life electric propulsion ion engines have become the preferred propulsion system for the new generation of spacecraft. Its working principle is as follows: first, the propellant is ionized using electrical energy, and the ionized ions are accelerated and drawn out during the process of passing through the grid assembly with an ultra-thin mesh structure, thereby generating long-term stable thrust. Among them, the grid assembly is the core component of the electric propulsion ion engine, and its design and manufacturing level directly determines the performance and life of the propulsion system.

[0003] At present, the key manufacturing technology of conventional metal molybdenum grid has been broken through, but the service life is only 14,000 hours, which is still a huge gap from the deep space exploration service life requirement of 40,000 hours. In order to improve the structural performance of ultra-thin mesh structure grid components, further research on the application of advanced materials must be carried out. Carbon-carbon composite materials have the advantages of light weight, high strength, low expansion, high temperature resistance and ion sputtering resistance, and are an ideal choice to replace metal molybdenum as the material of the grid component of the electric propulsion ion engine. At present, the principle verification of the 100mm-level ultra-thin carbon-carbon mesh grid has been completed. In order to make the deep space exploration spacecraft have sufficient thrust, it is necessary to carry out the design and manufacturing process research of large-diameter ultra-thin carbon-carbon mesh grids with an aperture of more than 300mm.

[0004] The process flow for preparing large-diameter ultra-thin carbon-carbon screen grids is roughly divided into three steps: blank forming, CVD deposition carbonization and finishing. Among them, blank forming is particularly critical as the first process, which is generally divided into two categories: winding forming and winding impregnation forming. When this process adopts the winding impregnation process, there are the following difficulties: In the winding impregnation process, different processes such as fiber wet winding, two high-temperature treatments and asphalt impregnation are involved. Different processes have different requirements for tooling structures. Among them, the fiber wet winding forming and the first high-temperature treatment process need to focus on avoiding the unevenness of the blank caused by the uneven surface of the pressing plate tooling; and the asphalt impregnation and the second high-temperature treatment process need to focus on avoiding the problem of asphalt being difficult to impregnate and small molecules being difficult to discharge during high-temperature treatment due to the excessively flat surface of the pressing plate tooling. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, and propose a winding and impregnation structure for an ultra-thin carbon-carbon screen mesh blank. By designing different types of pressing plates in the structure, different processes of the winding and impregnation molding process are completed, and finally an ultra-thin carbon-carbon screen mesh blank whose caliber, fiber orientation and material thickness meet the design requirements is obtained.

[0006] The technical solution of the present invention is:

[0007] A winding and impregnation structure of an ultra-thin carbon-carbon screen blank, comprising an upper pressing plate, a lower pressing plate, a combined winding plate and a triangular gasket;

[0008] The upper pressing plate and the lower pressing plate both include three different types: metal pressing plate, flat graphite pressing plate and graphite pressing plate with grid grooves, which are respectively used for different processes of the winding and impregnation molding process;

[0009] The combined wrapping plate is placed between the upper pressing plate and the lower pressing plate, and the upper pressing plate, the combined wrapping plate and the lower pressing plate are fixed and pressed by fixing parts;

[0010] The triangular gasket is used to be placed on the area of ​​the upper and lower surfaces of the combined winding plate that is not covered by the winding layer.

[0011] Furthermore, the combined winding plate includes two metal frames and a graphite core mold;

[0012] The two metal frames are spliced ​​into a closed structure, and the graphite core mold is stuck in the closed structure; the overlapping positions of the two metal frames are designed to be stepped and countersunk screw holes are processed along the thickness direction, and the countersunk screw holes are fixed with countersunk screws.

[0013] Furthermore, in order to ensure a firm fit between the metal frame and the graphite core mold, the contact surfaces between the two metal frames and the graphite core mold are designed to be boss-shaped, with the middle of the contact surface being a raised area, and the corresponding middle of the graphite core mold being designed to be concave.

[0014] Furthermore, the outer edges of the two metal frames are designed to include 3 short sides, 2 complete long sides and 2 long sides with steps; wherein the 2 long sides with steps are at the outermost ends on both sides, and the short sides are connected with the complete long sides at intervals; the 2 long sides with steps on the outer edge of one metal frame are overlapped with the 2 long sides with steps on the outer edge of the other metal frame, respectively, to form 2 long sides on the outer frame of the closed structure;

[0015] On the closed structure outer frame formed by two metal frames, grooves are respectively arranged on the six long sides, and the grooves are used to facilitate cutting of the side fibers after the pre-gel of the blank is completed; a tightening hole is respectively provided on the three short sides, and is used to fix to the tightening device of the winding equipment when preparing winding layers in different directions; a fixing screw hole is respectively provided on the other three short sides, and is used to fix to the clamping shaft of the winding equipment when preparing winding layers in different directions; the fixing screw holes correspond to the tightening holes one by one, and their positions differ by 180° along the circumferential direction.

[0016] Furthermore, the front sides of the upper pressing plate and the lower pressing plate are provided with a plurality of through holes, and the through holes are used to connect fixing parts to achieve the fixing and pressing of the upper pressing plate, the combined wrapping plate and the lower pressing plate.

[0017] Furthermore, the surface of the upper graphite plate with grid grooves in contact with the preform material is processed with grid grooves, and the surface of the lower graphite plate with grid grooves in contact with the preform material is processed with grid grooves, and the depth of the grid grooves is 1 to 1.5 mm.

[0018] Furthermore, the flat graphite upper pressure plate and the flat graphite lower pressure plate are used for the first high temperature treatment process, and the graphite upper pressure plate with grid grooves and the graphite lower pressure plate with grid grooves are used for the asphalt impregnation process and the second high temperature treatment process.

[0019] Furthermore, the winding and impregnation structure is also provided with a plurality of handles, which are respectively located at the outer edges of the upper pressing plate and the lower pressing plate; chamfers are respectively provided at both end surfaces of the handles to facilitate the handles to be embedded in the blind holes of different types of upper and lower pressing plates; the directions in which the handles are embedded in the lower pressing plate and the upper pressing plate are staggered to avoid affecting the cutting operation of the side fibers after the pre-gelation is completed.

[0020] Furthermore, there are multiple triangular gaskets, some of which are installed in the area between the upper pressure plate and the combined wrapping plate that is not covered by the wrapping layer, and the other part is installed in the area between the lower pressure plate and the combined wrapping plate that is not covered by the wrapping layer; the triangular gaskets are required to be used in the curing process of the blank forming, the two high-temperature treatment processes and the asphalt impregnation process.

[0021] Furthermore, the triangular gasket is designed to have a constant thickness, which is equal to the designed thickness of the ultra-thin carbon-carbon screen blank to be prepared, and the shape is designed according to the shape of the area not covered by the fiber winding layer.

[0022] The advantages of the present invention compared with the prior art are:

[0023] The present invention avoids the problem of uneven green body caused by uneven tooling surface in fiber wet winding molding and the first high-temperature treatment process by replacing different types of upper and lower pressure plate assemblies in different steps of the winding and impregnation molding process. It also avoids the process risks of difficulty in asphalt impregnation into the preform and difficulty in expelling small molecules during high-temperature treatment due to overly flat tooling surface in asphalt impregnation and the second high-temperature treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0025] Figure 1 A top view of the winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to an embodiment of the present invention;

[0026] Figure 2It is a side view of the winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to an embodiment of the present invention;

[0027] Figure 3 A top view of a combined winding plate structure according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the metal frame design of the combined wrapping plate according to an embodiment of the present invention;

[0029] Figure 5 This is a cross-sectional view of the combined winding plate structure of an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of a metal upper cover plate according to an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the structure of a metal lower cover plate according to an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure of a flat graphite upper pressure plate according to an embodiment of the present invention;

[0033] Fig. 9 This is a schematic diagram of the structure of a flat graphite lower pressure plate according to an embodiment of the present invention;

[0034] Fig.10 This is a schematic diagram of the structure of a graphite upper pressure plate with grid grooves according to an embodiment of the present invention;

[0035] Fig.11 This is a schematic diagram of the inner grid of the graphite upper platen with grid grooves according to an embodiment of the present invention;

[0036] Fig.12 This is a schematic diagram of the structure of a graphite lower pressure plate with grid grooves according to an embodiment of the present invention;

[0037] Fig.13 This is a schematic diagram of the inner grid of a graphite lower pressure plate with grid grooves according to an embodiment of the present invention;

[0038] Fig.14 This is a schematic diagram of the handle structure of an embodiment of the present invention;

[0039] Fig.15 Schematic diagram of a triangular gasket according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0041] The present invention proposes a winding and impregnation structure for an ultra-thin carbon-carbon screen blank. By replacing the pressing plate assembly in different processes, the difficulty of uneven blanks caused by uneven tooling surfaces in the fiber wet winding molding and the first high-temperature treatment process is solved. At the same time, the problem of difficulty in asphalt impregnation of the preform and difficulty in discharging small molecules during high-temperature treatment due to the excessively flat tooling surface in asphalt impregnation and the second high-temperature treatment process is avoided. The thickness of the prepared ultra-thin carbon-carbon screen blank does not exceed 1mm.

[0042] like Figure 1 , Figure 2 , Fig.15 As shown, the winding impregnation structure includes a handle 1, a circular gasket 2, a nut 3, a lower pressing plate 4, a combined winding plate 5, a screw 6, an upper pressing plate 7 and a triangular gasket 43. The upper pressing plate 7 and the lower pressing plate 4 both include three different types: a metal pressing plate, a flat graphite pressing plate and a graphite pressing plate with grid grooves, which are respectively used for different processes of the winding impregnation molding process. There are multiple handles 1, and one handle 1 is fixed to each of the two opposite sides of the upper pressing plate 7, and one handle 1 is fixed to each of the two opposite sides of the lower pressing plate 4. The lower surface of the combined winding plate 5 is pressed against the upper surface of the lower pressing plate 4, and the upper surface of the combined winding plate 5 is pressed against the lower surface of the upper pressing plate 7. The screw 6, the nut 3 and the circular gasket 2 jointly fix the combined winding plate 5, the upper pressing plate 7 and the lower pressing plate 4. The triangular gasket 43 is used to be placed in the area on the upper and lower surfaces of the combined winding plate 5 that is not covered by the winding layer to control the thickness of the preform in the fiber wet winding process and the curing process.

[0043] The handle 1 is embedded in the blind holes on the side of the lower pressing plate 4 and the upper pressing plate 7, and different types of pressing plate components can be inserted according to specific needs at different process stages. The round gasket 2, nut 3 and screw 6 can use standard parts.

[0044] like Figure 3 to Figure 5As shown, the combined wrapping plate 5 is assembled by a metal frame 11, a metal frame 17 and a graphite core mold 14 in the middle. The purpose of adopting this design is to facilitate the removal of metal parts before the asphalt impregnation process to avoid the difficulty of cleaning after the metal parts contact the asphalt. Among them, the overlapping position of the metal frame 11 and the metal frame 17 is designed to be stepped and countersunk screw holes 12 and 16 are processed along the thickness direction for fixing with countersunk screws, and the overlapping is achieved through the step 8, the butt joint 13 and the butt joint 15. The outer edges of the metal frame 11 and the metal frame 17 are designed to include 3 shorter sides, 2 complete long sides and 2 long sides with steps, wherein the 3 shorter sides are alternately processed with tightening holes and fixing screw holes, and the 2 long sides with steps are used to complete the splicing of the metal frame 11 and the metal frame 17, and the long sides with steps after splicing form 2 complete long sides, and no matter the complete long sides or the long sides with steps, the outer edge sides are processed with grooves 9, grooves 10, etc., a total of 6 grooves, which are used to facilitate cutting of side fibers after the pre-gelation of the blank is completed. In order to make the metal frame and the graphite core mold 14 firmly assembled, the contact surface between the two metal frames and the graphite core mold 14 is designed to be a boss shape, the middle part of the contact surface is a convex area, and the corresponding middle part of the graphite core mold 14 is designed to be concave.

[0045] like Figure 3 and Figure 4 As shown, the three shorter sides of the combined winding plate 5 are provided with tightening holes 18, 19 and 20. The tightening holes 18, 19 and 20 are used to fix to the tightening devices of the winding equipment when preparing winding layers in different directions, and the size and shape should be designed according to the tightening devices of the winding equipment used. In addition, the three shorter sides are provided with fixing screw holes 21, 22 and 23. The fixing screw holes correspond to the tightening holes one by one and the positions differ by 180° along the circumferential direction. The fixing screw holes 21, 22 and 23 are used to fix to the clamping shaft of the winding equipment when preparing winding layers in different directions, and the screw diameter and depth should be designed according to the clamping shaft of the winding equipment used.

[0046] The upper pressure plate is used in the fiber wet winding process. It has multiple through holes on the front side, where screws are installed. It has multiple blind holes on the side side, where handles are installed. Among them, the through hole opening positions of the three different types of upper pressure plates, namely the metal upper pressure plate 7, the flat graphite upper pressure plate 44 and the graphite upper pressure plate with grid grooves 46, are adjusted according to whether the metal frame of the combined winding plate is removed, so as to effectively fix the graphite core mold 14. The depth of the grid groove of the graphite upper pressure plate with grid grooves 46 is recommended to be 1 to 1.5 mm. Figure 6 As shown, the front of the metal upper pressing plate 7 is provided with through holes 24, 27, 28 and 31 for passing the screws 6. The side of the metal upper pressing plate 7 is provided with blind holes 25, 26, 29 and 30 for embedding the handle 1.

[0047] The lower pressure plate is used in the fiber wet winding process. It has multiple through holes on the front, where screws are installed. It has multiple blind holes on the side, where handles are installed. Among them, the through hole opening positions of the three different types of lower pressure plates, namely the metal lower pressure plate 4, the flat graphite lower pressure plate 45 and the graphite lower pressure plate with grid grooves 47, are adjusted according to whether the metal frame of the combined winding plate is removed, so as to effectively fix the graphite core mold 14. The grid groove depth of the graphite lower pressure plate with grid grooves 47 is recommended to be 1 to 1.5 mm. Figure 7 As shown, the front side of the metal pressing plate 4 is provided with through holes 32, 35, 36 and 39 for screws 6 to pass through and be fixed with the round gasket 2 and the nut 3. The side of the metal pressing plate 4 is provided with blind holes 33, 34, 37 and 38 for the handle 1 to be embedded.

[0048] The flat graphite upper pressing plate 44, the flat graphite lower pressing plate 45, the upper pressing plate 46 with grid grooves and the lower pressing plate 47 with grid grooves are respectively designed with corresponding through holes according to the size of the graphite core mold 14, such as Figure 8 to Figure 12 As shown, corresponding blind holes are designed according to the size of the handle 1. The functions of these through holes and blind holes are the same as Figure 6-7 The flat graphite upper pressing plate 44 and the flat graphite lower pressing plate 45 are used for the first high temperature treatment process, and the grid-grooved graphite upper pressing plate 46 and the grid-grooved graphite lower pressing plate 47 are used for the asphalt impregnation process and the second high temperature treatment process.

[0049] The surface of the upper graphite plate 46 with grid grooves in contact with the preform material is processed with grid grooves 40, such as Fig.11 As shown, it is used to make the asphalt fully contact with the porous preform material in the asphalt impregnation process and to make the small molecules released by the cracking of the asphalt escape in the second high-temperature treatment process. The surface of the graphite lower pressure plate 47 with grid grooves in contact with the preform material is processed with grid grooves 48, as shown in FIG. Fig.13 As shown, it is used to make the asphalt fully contact with the porous preform material in the asphalt impregnation process and to allow the small molecules released by the cracking of the asphalt to escape in the second high-temperature treatment process.

[0050] The two end surfaces of the handle 1 are provided with chamfers 41 and 42. Fig.14 As shown, the purpose of chamfers 41 and 42 is to facilitate the embedding of the handle 1 into the blind holes of different types of pressing plates; the handle is used to facilitate demoulding operations in various processes; the directions in which the handle 1 is embedded in the lower pressing plate and the upper pressing plate are staggered, the purpose of which is to avoid affecting the cutting operation of the side fibers after the pre-gel is completed.

[0051] There are multiple triangular gaskets, one part is installed in the area between the upper platen and the combined wrapping plate that is not covered by the wrapping layer, and the other part is installed in the area between the lower platen and the combined wrapping plate that is not covered by the wrapping layer. The triangular gaskets are required in the solidification process, two high-temperature treatment processes and asphalt impregnation process of the blank forming, and are used to control the gap size between the lower platen 4 and the combined wrapping plate 5, and between the upper platen 7 and the combined wrapping plate 5 in each process, so as to ensure the thickness of the composite material in the solidification process, leave enough gap for the pyrolysis material to be discharged smoothly in the two high-temperature treatment processes, and leave enough gap for the asphalt to be impregnated smoothly in the asphalt impregnation process. Fig.15 As shown, the triangular gasket 43 is designed with equal thickness, and the thickness is equal to the designed thickness of the ultra-thin carbon-carbon screen blank to be prepared. The triangular gasket 43 is used to be placed in the area not covered by the fiber winding layer between the lower pressing plate 4, the combined winding plate 5 and the upper pressing plate 7 during the fiber wet winding process and the curing process. In order to prevent the triangular gasket 43 from slipping during the pre-gelling and curing process of the composite material, it is recommended to grind the upper and lower surfaces of the triangular gasket 43 to increase the friction. The shape of the triangular gasket 43 is designed according to the specific shape of the area not covered by the fiber winding layer.

[0052] With the structure proposed by the present invention, the ultra-thin carbon-carbon screen blank can be wound and impregnated by switching Figure 6 to Figure 12 The different types of pressing plate assemblies shown can avoid problems such as uneven green body, difficulty in asphalt impregnation into the preform, and difficulty in expelling small molecules during high temperature treatment.

[0053] The present invention avoids the problem of uneven green body caused by uneven tooling surface in fiber wet winding molding and the first high-temperature treatment process by replacing special upper and lower pressure plate assemblies in different steps of the winding and impregnation molding process. It also avoids the process risks of difficulty in asphalt impregnation into the preform and difficulty in expelling small molecules during high-temperature treatment due to overly flat tooling surface in asphalt impregnation and the second high-temperature treatment process.

[0054] The specific manufacturing method is: select reinforcement fiber material and matrix material and determine the winding system; based on the selected reinforcement fiber material and matrix material, through winding tooling, adopt fiber wet winding process and solidify to prepare a composite material body; perform a first high-temperature treatment on the composite material body to obtain a porous preform; perform asphalt impregnation on the porous preform; after the asphalt impregnation is completed, perform a second high-temperature treatment to obtain a carbon-carbon screen blank.

[0055] The above-described embodiments are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A winding and impregnation structure of an ultra-thin carbon-carbon screen blank, characterized in that: It includes an upper pressing plate, a lower pressing plate, a combined winding plate and a triangular gasket; The upper pressing plate and the lower pressing plate both include three different types: metal pressing plate, flat graphite pressing plate and graphite pressing plate with grid grooves, which are respectively used for different processes of the winding and impregnation molding process; The combined wrapping plate is placed between the upper pressing plate and the lower pressing plate, and the upper pressing plate, the combined wrapping plate and the lower pressing plate are fixed and pressed by fixing parts; The triangular gasket is used to be placed on the area of ​​the upper and lower surfaces of the combined winding plate that is not covered by the winding layer.

2. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: The combined winding plate comprises two metal frames and a graphite core mold; The two metal frames are spliced ​​into a closed structure, and the graphite core mold is stuck in the closed structure; the overlapping positions of the two metal frames are designed to be stepped and countersunk screw holes are processed along the thickness direction, and the countersunk screw holes are fixed with countersunk screws.

3. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 2 is characterized in that: In order to ensure a firm fit between the metal frame and the graphite core mold, the contact surfaces between the two metal frames and the graphite core mold are designed to be boss-shaped, with the middle of the contact surface being a raised area, and the corresponding middle of the graphite core mold being designed to be concave.

4. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 2 is characterized in that: The outer edges of the two metal frames are designed to include 3 short sides, 2 complete long sides and 2 long sides with steps; the 2 long sides with steps are at the outermost ends on both sides, and the short sides are connected with the complete long sides at intervals; the 2 long sides with steps on the outer edge of one metal frame are overlapped with the 2 long sides with steps on the outer edge of the other metal frame, and are combined to form the 2 long sides on the outer frame of the closed structure; On the closed structure outer frame formed by two metal frames, grooves are respectively arranged on the six long sides, and the grooves are used to facilitate cutting of the side fibers after the pre-gel of the blank is completed; a tightening hole is respectively provided on the three short sides, and is used to fix to the tightening device of the winding equipment when preparing winding layers in different directions; a fixing screw hole is respectively provided on the other three short sides, and is used to fix to the clamping shaft of the winding equipment when preparing winding layers in different directions; the fixing screw holes correspond to the tightening holes one by one, and their positions differ by 180° along the circumferential direction.

5. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: The front sides of the upper pressing plate and the lower pressing plate are both provided with a plurality of through holes, and the through holes are used to connect fixing parts to realize the fixing and pressing of the upper pressing plate, the combined wrapping plate and the lower pressing plate.

6. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 1 or 5, characterized in that: The surface of the upper graphite plate with grid grooves in contact with the preform material is processed with grid grooves, and the surface of the lower graphite plate with grid grooves in contact with the preform material is processed with grid grooves, and the depth of the grid grooves is 1-1.5 mm.

7. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: The flat graphite upper platen and the flat graphite lower platen are used for the first high temperature treatment process, and the graphite upper platen with grid grooves and the graphite lower platen with grid grooves are used for the asphalt impregnation process and the second high temperature treatment process.

8. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 1 is characterized in that: The winding and impregnation structure is also provided with a plurality of handles, which are respectively located at the outer edges of the upper pressing plate and the lower pressing plate; chamfers are respectively provided at both end surfaces of the handles to facilitate the handles to be embedded in the blind holes of different types of upper and lower pressing plates; the directions in which the handles are embedded in the lower pressing plate and the upper pressing plate are staggered to avoid affecting the cutting operation of the side fibers after the pre-gelation is completed.

9. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 1, characterized in that: There are multiple triangular gaskets, some of which are installed in the area between the upper pressing plate and the combined wrapping plate that is not covered by the wrapping layer, and the other part is installed in the area between the lower pressing plate and the combined wrapping plate that is not covered by the wrapping layer; the triangular gaskets are required to be used in the curing process of the blank forming, the two high-temperature treatment processes and the asphalt impregnation process.

10. The winding and impregnation structure of the ultra-thin carbon-carbon screen blank according to claim 2, characterized in that: The triangular gasket is designed with equal thickness, which is equal to the designed thickness of the ultra-thin carbon-carbon screen blank to be prepared, and the shape is designed according to the shape of the area not covered by the fiber winding layer.

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