Weft-knitted spacer tube and preparation method of weft-knitted spacer tube made of carbon fiber reinforced composite material

Abstract

The invention relates to a weft knitting spacer tube and a preparation method of a carbon fiber reinforced composite weft knitting spacer tube, and belongs to the technical field of textile composite materials. The preparation method of the carbon fiber reinforced composite weft knitting spacer tube comprises the steps that S100, pre-impregnated carbon fibers are obtained; s200, weaving the pre-impregnated carbon fibers by using a weaving method of a weft-knitted spacer tube to obtain a carbon fiber weft-knitted spacer tube; and S300, heating and curing the carbon fiber weft-knitted spacer tube to obtain the carbon fiber reinforced composite weft-knitted spacer tube. According to the method, the carbon fiber reinforced composite weft-knitted spacer tube can be rapidly prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of textile composite materials, and in particular relates to a preparation method of a weft-knitted spacer tube and a carbon fiber reinforced composite material weft-knitted spacer tube. Background Art

[0002] At present, in the research of composite materials, light weight and high strength have become an important development trend of composite materials. Spacer fabrics have a unique three-dimensional structure, usually composed of two independent fabric layers and a spacer layer, which gives them many excellent properties. Spacer fabrics can effectively disperse and absorb energy when subjected to external forces, providing excellent cushioning performance. Its composite materials also have excellent mechanical properties and are widely used in aerospace, transportation, bridge construction and other fields. The combination of spacer structure and carbon fiber composite materials provides a larger lightweight design space for aerospace structures. The use of lightweight and efficient advanced structures can further achieve lightweight structures, such as new lightweight structures such as grid shells, reinforced shells and sandwich shell structures.

[0003] The prior art discloses some methods for preparing tubular structures and composite material tubes; the invention patent application CN118792795A discloses a knitted multi-layer hollow heterogeneous tubular structure stab-proof fabric and its preparation method, which discloses: a knitted multi-layer hollow heterogeneous tubular structure, which can be integrally woven into a tubular shape with the help of a four-needle bed computer flat knitting machine, greatly improving the production efficiency; the invention patent application CN116770501A discloses a warp-knitted seamless tubular composite material and its continuous production method, which discloses: a warp-knitted seamless tubular composite material preform, which is cylindrical and is woven on a double-needle bed Raschel warp knitting machine equipped with 10 yarn guide bars, integrally formed without side seams, and can be directly fed into a resin impregnation and curing molding device to continuously complete the production of tubular textile composite materials; the invention patent application CN116968339A discloses a fiber fabric composite material structure and its preparation method, which discloses: a fiber fabric A composite material structural part, the shape of which is tubular, and the tubular structural part is a fiber fabric composite material honeycomb tube supported by a fiber fabric composite material; invention patent application CN113977984A discloses a method for preparing a tubular hyperbolic composite material structural part: a method for preparing a tubular hyperbolic composite material structural part, which is prepared by using a mold of a metal male mold, a female mold forming mold and a flat mold forming mold, thereby achieving the integrity and surface accuracy of a complex shape, and ensuring high-quality demolding and smooth appearance of the product; invention patent application CN113320237A tubular composite material and its preparation method and application discloses: a tubular composite material and its preparation method and application, a tubular composite material such as a cylinder or a pipe, by adding at least one bundle layer between at least two winding layers to enhance the axial strength of the pipe, having a sandwich structure, and being suitable for occasions with high requirements for axial mechanical properties.

[0004] Therefore, tubular structures mostly use fiber winding technology, interlocking assembly, mold hot pressing and other methods. The fiber winding process can realize continuous fiber laying and is easy to automate, but it requires the design of a special mold according to the shape and size of the product, which is relatively expensive. In the fiber winding process, due to the influence of factors such as fiber tension and winding speed, the fiber winding may be uneven, affecting the performance of the product; although the interlocking assembly and mold hot pressing processes can realize the manufacture of diversified structures, there are also problems such as complex processes and high mold costs. At present, there is a lack of rapid prototyping and low-cost production methods for complex structure composite materials. Knitting technology is an effective way to achieve mass production, automated production, and reduce costs. Through the programming settings of computer software, the weaving of complex structure materials can be realized. The knitted spacer structure has a three-dimensional structure and is also a sandwich structure with excellent cushioning and energy absorption properties.

[0005] In summary, the existing tubular structures can be manufactured by knitting technology, and most of them are hollow or single-layer structures. The composite material tubes are mostly manufactured by curing molding, compression molding, winding molding, etc. The preparation process is complicated and cumbersome, and does not involve one-piece weft knitted spacer tubes and composite material tubes. Therefore, in view of the technical problems of the prior art, combined with knitting technology, a preparation method of weft knitted spacer tubes and carbon fiber reinforced composite material weft knitted spacer tubes is proposed to meet the requirements of one-piece molding of fiber reinforced tubes of spacer composite materials. Summary of the invention

[0006] The present invention application proposes a method for preparing a weft-knitted spacer tube and a carbon fiber reinforced composite material weft-knitted spacer tube, aiming to partially or completely solve the technical problem that the prior art cannot quickly produce a carbon fiber reinforced composite material spacer tube. The present invention application can quickly prepare a carbon fiber reinforced composite material weft-knitted spacer tube. In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] In a first aspect, a method for preparing a weft-knitted spacer tube comprises:

[0008] Step S1, knitting on a Stoll computerized flat knitting machine, performing one-by-one looping on the front and rear needle beds respectively, to form an inner surface layer and an outer surface layer of the spacer tube, and the number of knitting rows of the outer surface layer must be greater than the number of knitting rows of the inner surface layer;

[0009] Step S2, performing tucking on the front and rear needle beds to form a middle spacer layer of the spacer tube, all tucking actions in one spacer need to be staggered, the number of knitting rows of the spacer layer is 1 or 2 or 3 or 4..., and the corresponding number of spacers is one-to-one or one-to-three or one-to-five or one-to-seven..., and so on;

[0010] Step S3, steps S1 and S2 are a cyclic knitting action, and steps S1 and S2 are repeated for multiple cycles;

[0011] Step S4, after the machine is removed, the first row of spacer stitches and the last row of spacer stitches are sewn together to obtain a weft-knitted spacer tube.

[0012] Optionally, the ratio of the number of knitting rows of the inner surface layer to the number of knitting rows of the outer surface layer is 1:2 or 1:3 or 2:3 or 3:4.

[0013] In a second aspect, a method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube comprises:

[0014] Step S100: obtaining pre-impregnated carbon fiber;

[0015] Step S200: Weaving the pre-impregnated carbon fiber using the weft-knitted spacer tube weaving method described in any one of the first aspects of the above claims to obtain a carbon fiber weft-knitted spacer tube;

[0016] Step S300: heating and curing the carbon fiber weft-knitted spacer tube to obtain a carbon fiber reinforced composite material weft-knitted spacer tube.

[0017] Optionally, step S100 includes:

[0018] Step S101, diluting thermoplastic polyimide TPI liquid resin and organic solvent N,N-dimethylformamide DMF in proportion;

[0019] Step S102, pre-impregnating the diluted thermoplastic polyimide TPI liquid resin and carbon fiber in a homemade sizing machine;

[0020] Step S103, preliminarily curing the preimpregnated carbon fiber, volatilizing part of the DMF, reducing the surface viscosity of the preimpregnated composite carbon fiber, and collecting the preimpregnated composite carbon fiber.

[0021] Optionally, in step S101, the dilution ratio of the thermoplastic polyimide TPI liquid resin to the organic solvent N,N-dimethylformamide DMF is 1:2 or 1:3 or 1:4 or 1:5 or 2:3.

[0022] Optionally, the temperature and time of the initial curing are 20° C.-80° C. and 10-60 min.

[0023] Optionally, the temperature and time of heating curing are 180° C.-260° C. and 30-90 min.

[0024] Optionally, step S300 includes: placing the carbon fiber weft-knitted spacer tube in an oven for heating and curing to obtain a carbon fiber reinforced composite material weft-knitted spacer tube.

[0025] The beneficial effects achieved by the present invention are as follows:

[0026] (1) In the present application, weaving is carried out on a Stoll computerized flat knitting machine with a spacing structure and integrated weaving. The thickness and width of the tube can be adjusted by software as needed, thereby achieving rapid production, saving manpower, raw material and time costs, and avoiding waste of resources.

[0027] (2) In the present invention, no mold is required, and no secondary composite treatment is required, which greatly reduces the production cost. The spacer structure is evenly distributed, which allows the composite pipe to withstand pressure to a certain extent, increases the force range and force direction of the composite pipe, reduces the material and weight compared to solid structural parts, saves costs, and has a stronger force bearing capacity than hollow structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic diagram of a process for preparing a weft-knitted spacer tube according to the present invention;

[0030] Figure 2 A schematic diagram of the weaving process of the weft-knitted spacer tube applied for in the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the weft-knitted spacer tube applied for in the present invention;

[0032] Figure 4 A schematic diagram of the process of preparing the carbon fiber reinforced composite material weft-knitted spacer tube of the present invention;

[0033] Figure 5 A schematic cross-sectional view of a carbon fiber reinforced composite material weft-knitted spacer tube according to the present invention;

[0034] Figure 6 This is a physical schematic diagram of the carbon fiber reinforced composite material weft-knitted spacer tube applied for in the present invention.

[0035] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. "Including" can at least be understood as the meaning of only including. In order to make the purpose, technical solutions and advantages of the present invention clearer, the implementation methods of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0038] A method for preparing a weft-knitted spacer tube

[0039] First, as Figures 1 to 6 As shown, a method for preparing a weft-knitted spacer tube comprises:

[0040] Step S1, knitting on a Stoll computerized flat knitting machine, performing one-by-one looping on the front and rear needle beds respectively, to form an inner surface layer and an outer surface layer of the spacer tube, and the number of knitting rows of the outer surface layer must be greater than the number of knitting rows of the inner surface layer;

[0041] In some embodiments, the number of weaving rows can be adjusted according to the desired surface layer width. It should be noted that in order to form a tubular shape, the number of weaving rows of the outer surface layer 10 needs to be greater than the number of weaving rows of the inner surface layer 30 .

[0042] Step S2, performing tucking on the front and rear needle beds to form a middle spacer layer of the spacer tube, all tucking actions in one spacer need to be staggered, the number of knitting rows of the spacer layer is 1 or 2 or 3 or 4..., and the corresponding number of spacers is one-to-one or one-to-three or one-to-five or one-to-seven..., and so on;

[0043] In some embodiments, the number of weaving rows of the spacer layer 20 can be adjusted according to the desired spacer thickness. It should be noted that in order to avoid compression of the fabric edge, the position of the tuck rows within a spacer is adjusted so that the tucks at the edge are evenly distributed;

[0044] Step S3, steps S1 and S2 are a cyclic knitting action, and steps S1 and S2 are repeated for multiple cycles;

[0045] Step S4, after the machine is removed, the first row of spacer stitches and the last row of spacer stitches are sewn together to obtain a weft-knitted spacer tube.

[0046] In the present invention application, the knitting is carried out on a Stoll computer flat knitting machine, which has a spacer structure and is woven in one piece. The thickness and width of the tube can be adjusted by software as needed, so as to achieve rapid production, save manpower, raw materials and time costs, and avoid waste of resources.

[0047] Optionally, the ratio of the number of knitting rows of the inner surface layer to the number of knitting rows of the outer surface layer is 1:2 or 1:3 or 2:3 or 3:4.

[0048] In some embodiments, the ratio of the number of knitting rows of the inner surface layer to the number of knitting rows of the outer surface layer is 1:2 or 1:3 or 2:3 or 3:4. Of course, those skilled in the art can also reasonably set the ratio of the number of knitting rows of the inner surface layer to the number of knitting rows of the outer surface layer according to actual needs.

[0049] In the present application, the automation characteristics of the Stoll computer flat knitting machine are utilized to quickly adjust the thickness and width of the spacer tube according to actual needs, thereby greatly shortening the production cycle, greatly reducing the manpower input in the traditional multi-step process, and significantly reducing the production cost. The ratio of the number of weaving rows between the inner surface layer and the outer surface layer (for example, 1:2, 1:3, 2:3 or 3:4) can be flexibly adjusted according to actual needs to meet diverse application scenarios. The spacer structure design is adopted to enhance the product's breathability, elasticity and comfort, improve functionality and user experience, improve production efficiency, provide technical support for personalized customization, and have broad technical and market application prospects.

[0050] A method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube

[0051] In a second aspect, a method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube comprises:

[0052] Step S100: obtaining pre-impregnated carbon fiber;

[0053] Step S200: Weaving the pre-impregnated carbon fiber using any weft-knitted spacer tube weaving method described in the first aspect to obtain a carbon fiber weft-knitted spacer tube;

[0054] Step S300: heating and curing the carbon fiber weft-knitted spacer tube to obtain a carbon fiber reinforced composite material weft-knitted spacer tube.

[0055] In the present invention, no mold is required, and no secondary composite treatment is required, which greatly reduces the production cost. The evenly distributed spacing structure can make the composite pipe withstand pressure to a certain extent, increase the force range and force direction of the composite pipe, reduce the material and weight compared with solid structural parts, save costs, and have stronger force bearing capacity compared with hollow structural parts.

[0056] Optionally, step S100 includes:

[0057] Step S101, diluting thermoplastic polyimide TPI liquid resin and organic solvent N,N-dimethylformamide DMF in proportion;

[0058] Step S102, pre-impregnating the diluted thermoplastic polyimide TPI liquid resin and carbon fiber in a sizing machine;

[0059] Step S103, preliminarily curing the preimpregnated carbon fiber, volatilizing part of the DMF, reducing the surface viscosity of the preimpregnated composite carbon fiber, and collecting the preimpregnated composite carbon fiber;

[0060] In the present application, firstly, by diluting the thermoplastic polyimide TPI liquid resin and the organic solvent N,N-dimethylformamide DMF in proportion, the viscosity of the resin can be effectively adjusted to ensure that it evenly covers the carbon fiber surface during the impregnation process, which not only improves the impregnation quality, but also enhances the interface bonding performance of the subsequent composite material; in addition, the diluted TPI liquid resin and carbon fiber are pre-impregnated in a sizing machine, thereby achieving the goal of accurately controlling the impregnation conditions, which can better ensure the uniform distribution between the carbon fiber and the resin, and improve the overall mechanical properties and stability of the composite material; in addition, by preliminarily curing the pre-impregnated carbon fiber and volatilizing part of the DMF, the surface viscosity of the composite carbon fiber is effectively reduced, the fiber entanglement or operation difficulty caused by excessive viscosity is avoided, and the processability and surface quality of the composite material are improved; finally, by collecting the pre-impregnated composite carbon fiber, continuous and automated production is achieved, which greatly reduces manual intervention, reduces production costs, and improves production efficiency, which is suitable for the preparation of weft-knitted spacer tubes of carbon fiber reinforced composite materials.

[0061] Optionally, step S300 includes: placing the carbon fiber weft-knitted spacer tube in an oven for heating and curing to obtain a carbon fiber reinforced composite material weft-knitted spacer tube.

[0062] In the present invention application, firstly, the heating and curing process enables the thermoplastic resin to fully penetrate and evenly wrap the carbon fiber to form a stable three-dimensional structure, thereby improving the mechanical properties of the composite material and meeting the industrial demand for high-performance materials; in addition, the heating and curing process is simple to operate and highly controllable, and can achieve mass production, greatly reducing production costs and improving production efficiency.

[0063] Optionally, in step S101, the dilution ratio of thermoplastic polyimide TPI liquid resin to organic solvent N,N-dimethylformamide DMF is 1:2 or 1:3 or 1:4 or 1:5 or 2:3;

[0064] In the present application, by precisely controlling the dilution ratio of TPI liquid resin to DMF (1:2 or 1:3), the resin viscosity can be effectively adjusted so that the resin can evenly impregnate the carbon fiber, improve the interface bonding strength, and improve the overall mechanical properties and stability of the composite material.

[0065] Optionally, the temperature and time of the initial curing are 20°C-80°C, 10-60min;

[0066] In the present application, the temperature and time of the preliminary curing are 20°C-80°C and 10-60min. Preferably, the setting of the temperature (25°C) and time (30min) of the preliminary curing can reduce the surface viscosity of the pre-impregnated carbon fiber at a lower energy consumption, avoid the fiber winding problem, and simplify the subsequent processing flow to improve production efficiency.

[0067] Optionally, the temperature and time of heating curing are 180° C.-260° C. and 30-90 min.

[0068] In the present application, the temperature and time of heating and curing are 180°C-260°C and 30-90min. Preferably, the temperature (180°C) and time (90min) of heating and curing ensure that the thermoplastic polyimide TPI liquid resin is fully cured to form a stable three-dimensional network structure, which not only enhances the mechanical properties of the composite material, but also ensures its excellent heat resistance and chemical stability, meeting the performance requirements of the carbon fiber reinforced composite weft-knitted spacer tube.

[0069] Exemplary description of the weaving method of weft knitted spacer tube A and weft knitted spacer tube B

[0070] (1) A weaving method of a weft-knitted spacer tube A, comprising:

[0071] Step S1A, knitting on a Stoll computerized flat knitting machine, performing one-by-one looping on the front and rear needle beds respectively, to form the inner and outer layers of the spacer tube, the outer layer adopts three rows of looping for the outer layer, and the inner layer adopts two rows of looping for the inner layer;

[0072] Step S2A, performing tuck stitches on the front and rear needle beds to form a middle spacer layer of the spacer tube, the number of knitting rows of the spacer layer is 4 rows, the spacer layer adopts one-to-seven tuck stitches, and all tuck stitches in one spacer need to be staggered;

[0073] In some embodiments, the number of knitting rows can be adjusted according to the desired interval thickness. It should be noted that in order to avoid compression of the fabric edge, the position of the tuck rows within an interval is adjusted so that the tucks at the edge are evenly distributed;

[0074] Step S3A, steps S1A and S2A are a cyclic knitting action, and steps S1A and S2A are repeated multiple times;

[0075] Step S4A, after the machine is removed, the first row of spacer loops and the last row of spacer loops are sewn together to obtain a weft-knitted spacer tube.

[0076] (2) A weaving method of a weft-knitted spacer tube B, comprising:

[0077] Step S1 B, knitting on a Stoll computerized flat knitting machine, performing one-by-one looping on the front and rear needle beds respectively, to form the inner and outer layers of the spacer tube, the outer layer adopts 4 rows of looping by spacer needles, and the inner layer adopts 3 rows of looping by spacer needles;

[0078] Step S2B, performing tucking on the front and rear needle beds to form a middle spacer layer of the spacer tube, the number of knitting rows of the spacer layer is 3 rows, the spacer layer adopts one-to-five tucking, and all tucking actions in one interval need to be staggered;

[0079] In some embodiments, the number of knitting rows can be adjusted according to the desired interval thickness. It should be noted that in order to avoid compression of the fabric edge, the position of the tuck rows within an interval is adjusted so that the tucks at the edge are evenly distributed;

[0080] Step S3B, steps S1 B and S2B are a cyclic knitting action, and steps S1 B and S2B are repeated multiple times;

[0081] Step S4B, after the machine is removed, the first row of spacer stitches and the last row of spacer stitches are sewn together to obtain a weft-knitted spacer tube.

[0082] Preparation method of carbon fiber reinforced composite material weft knitted spacer tube A and carbon fiber reinforced composite material weft knitted spacer tube B Example Description

[0083] (1) Carbon fiber reinforced composite material weft knitted spacer tube A

[0084] Step S100A: obtaining pre-impregnated carbon fiber;

[0085] Step S200A: Weaving the pre-impregnated carbon fiber using a weft-knitted spacer tube A weaving method to obtain a carbon fiber weft-knitted spacer tube A;

[0086] Step S300A: heating and curing the carbon fiber weft-knitted spacer tube A to obtain a carbon fiber reinforced composite material weft-knitted spacer tube A.

[0087] Step S100A includes:

[0088] Step S101A, diluting the thermoplastic polyimide TPI liquid resin and the organic solvent N,N-dimethylformamide DMF in a ratio of 1:2;

[0089] Step S102A, pre-impregnating the diluted thermoplastic polyimide TPI liquid resin and carbon fiber in a sizing machine;

[0090] Step S103A, preliminarily curing the preimpregnated carbon fiber at 25° C. for 30 min to volatilize some DMF, reduce the surface viscosity of the preimpregnated composite carbon fiber, and collect the preimpregnated composite carbon fiber;

[0091] Step S300A includes: placing the carbon fiber weft-knitted spacer tube A in an oven for heating and curing at 180° C. for 90 minutes to obtain the carbon fiber reinforced composite material weft-knitted spacer tube A.

[0092] (2) Carbon fiber reinforced composite material weft knitted spacer tube B

[0093] Step S100B: obtaining pre-impregnated carbon fiber;

[0094] Step S200B: Weaving the pre-impregnated carbon fiber using a weft-knitted spacer tube B weaving method to obtain a carbon fiber weft-knitted spacer tube B;

[0095] Step S300A: heating and curing the carbon fiber weft-knitted spacer tube B to obtain a carbon fiber reinforced composite material weft-knitted spacer tube B.

[0096] Step S100B includes:

[0097] Step S101 B, diluting the thermoplastic polyimide TPI liquid resin and the organic solvent N,N-dimethylformamide DMF in a ratio of 1:3;

[0098] Step S102B, pre-impregnating the diluted thermoplastic polyimide TPI liquid resin and carbon fiber in a homemade sizing machine;

[0099] Step S103B, preliminarily curing the preimpregnated carbon fiber at 25° C. for 20 min to volatilize some DMF, reduce the surface viscosity of the preimpregnated composite carbon fiber, and collect the preimpregnated composite carbon fiber;

[0100] Step S300B includes: placing the carbon fiber weft-knitted spacer tube B in an oven for heating and curing at 180° C. for 90 minutes to obtain the carbon fiber reinforced composite material weft-knitted spacer tube B.

[0101] The drawings are only one of the embodiments of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design a structure and embodiment similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a weft-knitted spacer tube, characterized in that: include: Step S1, knitting on a Stol l computer flat knitting machine, knitting one loop at a time on the front and rear needle beds respectively, to form an inner surface layer and an outer surface layer of the spacer tube, and the number of knitting rows of the outer surface layer must be greater than the number of knitting rows of the inner surface layer; Step S2, performing tucking on the front and rear needle beds to form a middle spacer layer of the spacer tube, all tucking actions in one spacer need to be staggered, the number of knitting rows of the spacer layer is 1 or 2 or 3 or 4..., and the corresponding number of spacers is one-to-one or one-to-three or one-to-five or one-to-seven..., and so on; Step S3, steps S1 and S2 are a cyclic knitting action, and steps S1 and S2 are repeated for multiple cycles; Step S4, after the machine is removed, the first row of spacer stitches and the last row of spacer stitches are sewn together to obtain a weft-knitted spacer tube.

2. The method for preparing a weft-knitted spacer tube according to claim 1, characterized in that: The ratio of the number of weaving rows of the inner surface layer to the number of weaving rows of the outer surface layer is 1:2 or 1:3 or 2:3 or 3:

4.

3. A method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube, characterized in that: include: Step S100: obtaining pre-impregnated carbon fiber; Step S200: Weaving the pre-impregnated carbon fiber using the weft-knitted spacer tube weaving method described in any one of claims 1 to 2 to obtain a carbon fiber weft-knitted spacer tube; Step S300: heating and curing the carbon fiber weft-knitted spacer tube to obtain a carbon fiber reinforced composite material weft-knitted spacer tube.

4. The method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube according to claim 3, characterized in that: Step S100 includes: Step S101, diluting thermoplastic polyimide TPI liquid resin and organic solvent N,N-dimethylformamide DMF in proportion; Step S102, pre-impregnating the diluted thermoplastic polyimide TPI liquid resin and carbon fiber in a sizing machine; Step S103, preliminarily curing the preimpregnated carbon fiber, volatilizing part of the DMF, reducing the surface viscosity of the preimpregnated composite carbon fiber, and collecting the preimpregnated composite carbon fiber.

5. The method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube according to claim 3, characterized in that: In step S101 , the dilution ratio of thermoplastic polyimide TPI liquid resin and organic solvent N,N-dimethylformamide DMF is 1:2 or 1:3 or 1:4 or 1:5 or 2:

3.

6. The method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube according to claim 4, characterized in that: The temperature and time of initial curing are 20℃-80℃, 10-60min.

7. The method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube according to claim 3, characterized in that: The temperature and time of heating curing are 180°C-260°C and 30-90 minutes.

8. The method for preparing a carbon fiber reinforced composite material weft-knitted spacer tube according to claim 3, characterized in that: Step S300 includes: placing the carbon fiber weft-knitted spacer tube in an oven for heating and curing to obtain a carbon fiber reinforced composite material weft-knitted spacer tube.

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