A guide tube support ring fiber preform and preparation method thereof and guide tube support ring

Abstract

The present invention relates to a guide tube support ring fiber preform and a preparation method thereof and a guide tube support ring, the preparation method comprising: first, designing and preparing a first structural unit layer of asphalt-based carbon fiber cloth, asphalt-based carbon fiber mesh and polyacrylonitrile-based carbon fiber mesh composite, and a second structural unit layer of asphalt-based carbon fiber cloth and mixed fiber mesh composite; then performing zoned plying and needle punching corresponding to the performance requirements of different positions of the guide tube support ring; and then obtaining an integrally formed guide tube support ring fiber preform through processes such as in-plane stitching, interlayer stitching and overall stitching. The preparation method provided by the present invention can simultaneously ensure the high temperature resistance, heat insulation and mechanical properties of the guide tube support ring, and ensure that the guide tube support ring can stably support and fix the guide tube under harsh working environments.

Description

Technical Field

[0001] The invention relates to the technical field of fiber preform preparation, and in particular to a guide tube support ring fiber preform and a preparation method thereof, and a guide tube support ring. Background Art

[0002] The guide tube support ring is an annular structure used to support the guide tube. It is located at the bottom of the guide tube. The guide tube can be stably installed in the required position through the support ring and can withstand a certain external pressure. The guide tube support ring usually requires strong high temperature resistance, usually requiring to withstand high temperatures above hundreds of degrees Celsius and operate stably for a long time; it has good thermal insulation, reduces the loss of heat energy and maintains the high temperature environment inside the thermal field, improves the thermal efficiency of the thermal field, and protects the external structure from the influence of excessive temperature, improves the efficiency and quality of crystal growth; and has good mechanical properties, can withstand certain mechanical loads in high temperature environments, can resist stress and deformation, thereby improving service life, etc.

[0003] According to the structural classification of the guide tube support ring, it generally includes an upper ring, an intermediate ring plate and a lower ring. The upper ring and the intermediate ring plate are used to connect with the bottom of the guide tube close to the crucible. Therefore, the material at the connection is in a higher ambient temperature and is required to have good high temperature stability and be able to withstand a long-term high temperature environment without damage. It is also required to have good thermal insulation to reduce heat loss and maintain the temperature gradient between the inside and outside of the thermal field, thereby ensuring the growth efficiency and quality of the crystal. The lower ring is an important component that plays a supporting role and needs to have good strength and modulus to ensure stable support and fixation of the guide tube in harsh working environments.

[0004] For example, CN214736204U discloses a flow guide tube and a flow guide assembly, wherein the flow guide tube includes an inner flow guide tube, an outer flow guide tube and a support ring, wherein the support ring is arranged on the inner side of the outer flow guide tube and connected to the end of the outer flow guide tube close to the crucible, and the support ring is a graphite support ring; the inner flow guide tube is a cavity-type structure with openings at both ends, and the end close to the crucible is arranged on the support ring, and the inner flow guide tube is a quartz inner flow guide tube; the outer flow guide tube is a cavity-type structure with openings at both ends, and the cover is arranged on the outer side of the inner flow guide tube. Although the above-mentioned graphite support ring can play the role of supporting the flow guide tube, its high temperature resistance and heat insulation effect are not good.

[0005] At present, commonly used carbon fiber thermal insulation materials mainly include carbon fiber soft felt and carbon fiber hard felt. Among them, carbon fiber soft felt has the disadvantages of low strength, easy deformation, easy powdering, poor thermal insulation effect, and time-consuming and labor-intensive disassembly and installation. Carbon fiber hard felt includes three types: viscose-based, PAN-based and asphalt-based. Although viscose-based carbon fiber has a small thermal conductivity and is theoretically the most suitable for thermal insulation materials, its antioxidant properties and strength are not as good as asphalt-based carbon fiber. Thermal insulation materials produced using asphalt-based carbon fiber have the following advantages: (1) excellent thermal insulation performance; (2) high carbon content, low volatile matter, and low pollution; (3) high strength.

[0006] Therefore, providing a guide tube support ring fiber preform prepared with asphalt-based carbon fiber and using it in the preparation of the guide tube support ring is beneficial to improving the mechanical strength, thermal insulation and high temperature resistance of the guide tube support ring, which is of great significance for maintaining the thermal field safety of the high-temperature furnace. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to provide a method for preparing a fiber preform of a guide tube support ring. Compared with the prior art, the present invention designs the structural unit layer according to the performance requirements of different positions of the guide tube support ring, and improves the interlayer bonding strength through the process of partitioned plying, needling and stitching, thereby ensuring the high temperature resistance, thermal insulation and mechanical properties of the guide tube support ring at the same time, so as to ensure that the guide tube support ring can stably support and fix the guide tube under harsh working environment.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a guide tube support ring fiber preform, the preparation method comprising the following steps:

[0010] S1. Preparation of structural unit layer:

[0011] Compounding a layer of asphalt-based carbon fiber cloth with a layer of asphalt-based carbon fiber mesh and a layer of polyacrylonitrile-based carbon fiber mesh to form a first structural unit layer;

[0012] Compounding a layer of asphalt-based carbon fiber cloth with a layer of mixed fiber web tire to form a second structural unit layer;

[0013] S2. Partitioned layer needling:

[0014] On the forming mold, the first structural unit layer is laid in the area where the lower ring is located and needle-punched layer by layer to a preset thickness, and the second structural unit layer is laid in the area where the ring plate and the upper ring are located and needle-punched layer by layer to a preset thickness;

[0015] S3. Suture:

[0016] The butt joint is sutured in the annular butt joint area by using a suture thread, and then interlayer suture is performed to form a main structure. After that, a continuous fiber cloth is integrally laid on the outer surface of the main structure and sutured as a whole to obtain the guide tube support ring fiber preform.

[0017] In the preparation method of the guide tube support ring fiber preform provided by the present invention, on the one hand, the structural unit layer is designed according to the performance requirements of different positions of the guide tube support ring to meet the multiple needs of the support ring for heat resistance, heat insulation and support. Among them, the lower ring plays a major supporting role, so the first structural unit layer composed of a three-layer structure of asphalt-based carbon fiber cloth, asphalt-based carbon fiber mesh, and polyacrylonitrile-based carbon fiber mesh is designed, and at least one layer of the first structural unit layer is needle-punched to a preset thickness by contoured plying, which can effectively exert the good hardness and modulus of the polyacrylonitrile-based carbon fiber mesh, and improve the mechanical strength of the preform, so as to ensure that the guide tube is stably supported and fixed in a harsh working environment. The upper ring and the ring plate are used to connect with the bottom of the guide tube near the crucible, and require good heat resistance and thermal insulation. Therefore, the second structural unit layer composed of asphalt-based carbon fiber cloth and mixed fiber mesh is designed. At least one layer of the second structural unit layer is contoured and needle-punched to a preset thickness. By adjusting the doping ratio of the fibers in the mixed fiber mesh, the heat resistance and thermal insulation of the asphalt-based carbon fiber can be fully utilized. The damage tolerance of the structure is improved through the interaction of different fibers, the resistance to harsh working environment is enhanced, and the growth efficiency and quality of the crystal are guaranteed. On the other hand, the present invention adopts a variety of stitching processes such as in-plane stitching, interlayer stitching and overall stitching, among which in-plane stitching refers to stitching the joint seams of the annular joint areas of the upper ring, the ring plate and the lower ring, which can enhance the joining strength of the preform, reduce the stress concentration caused by the discontinuous fiber arrangement at the joints, reduce the risk of cracks, and improve fatigue resistance and life; interlayer stitching refers to the overall interlayer needling stitching of the structure obtained after the partitioned ply needle punching to obtain the main structure, which can improve the interlayer bonding force, improve the interlayer shear strength and interlayer fracture toughness, and avoid the risk of interlayer delamination during use; overall stitching refers to the use of continuous fiber cloth laid as a whole on the outer surface of the main structure, and then the continuous fiber cloth and the main structure are again subjected to the overall interlayer needling stitching, which can promote the uniform distribution of stress and further improve the integrity and consistency of the preform structure.

[0018] Preferably, in step S1, the thickness ratio of the asphalt-based carbon fiber mesh and the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer is (6-11):5, for example, it can be 6:5, 7:5, 8:5, 9:5, 10:5 or 11:5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In the present invention, by preferably controlling the thickness ratio of the asphalt-based carbon fiber mesh and the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer within a specific range, it is possible to fully utilize the strength and modulus of the polyacrylonitrile-based carbon fiber mesh while utilizing the heat resistance of the asphalt-based carbon fiber, thereby improving the support of the lower annular portion.

[0020] Preferably, the surface density of the asphalt-based carbon fiber cloth is 275-390 g / m 2 , for example, it can be 275g / m 2 , 280g / m 2 , 285g / m 2 , 290g / m 2 , 295g / m 2 , 300g / m 2 , 305g / m 2 , 310g / m 2 , 315g / m 2 , 320g / m 2 , 325g / m 2 , 330g / m 2 , 335g / m 2 , 340g / m 2 , 345g / m 2 , 350g / m 2 , 355g / m 2 , 360g / m 2 , 365g / m 2 , 370g / m 2 , 375g / m 2 , 380g / m 2 , 385g / m 2 or 390g / m 2 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the asphalt-based carbon fiber mesh tread density is 60-85 g / m 2 , for example, it can be 60g / m 2 , 62g / m 2 , 64g / m 2 , 66g / m 2 , 68g / m 2 , 70g / m 2 , 72g / m 2 , 74g / m 2 , 76g / m 2 , 78g / m 2 , 80g / m 2 , 82g / m 2 , 84g / m 2or 85g / m 2 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the surface density of the polyacrylonitrile-based carbon fiber mesh is 35-45 g / m 2 , for example, it can be 35g / m 2 , 36g / m 2 , 38g / m 2 , 40g / m 2 , 41g / m 2 , 42g / m 2 , 43g / m 2 , 44g / m 2 or 45g / m 2 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the surface density of the mixed fiber web is 55-75g / m 2 , for example, it can be 55g / m 2 , 56g / m 2 , 58g / m 2 , 60g / m 2 , 62g / m 2 , 64g / m 2 , 66g / m 2 , 68g / m 2 , 70g / m 2 , 72g / m 2 , 74g / m 2 or 75g / m 2 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the mixed fiber mesh described in step S1 is made by mixing asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber in a mass ratio of (2-5):1 and then undergoing a mesh forming process. For example, it can be 2:1, 3:1, 4:1 or 5:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] In the present invention, by preferably controlling the mass ratio of asphalt-based carbon fiber to polyacrylonitrile-based carbon fiber in the mixed fiber mesh within a specific range, the synergistic effect of asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber can be optimized, thereby improving the heat resistance and thermal insulation of the upper ring and ring plate.

[0026] Preferably, the acupuncture density in step S2 is 20-35 needles / cm 2 , for example, 20 needles / cm 2 , 21 needles / cm2 , 22 needles / cm 2 , 23 needles / cm 2 , 24 needles / cm 2 , 25 needles / cm 2 , 26 needles / cm 2 , 27 needles / cm 2 , 28 needles / cm 2 , 29 needles / cm 2 , 30 needles / cm 2 , 31 needles / cm 2 , 32 needles / cm 2 , 33 needles / cm 2 , 34 needles / cm 2 or 35 needles / cm 2 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the acupuncture depth is 12-16 mm, for example, 12 mm, 13 mm, 14 mm, 15 mm or 16 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Preferably, the radial joints of the lower circular ring, the ring plate and the upper circular ring are located on the same straight line.

[0029] Preferably, the in-plane suture in step S3 includes: suture in the circumferential butt joint area of ​​15-30 mm on both sides of the butt joint as the center, for example, it can be 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm or 30mm, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0030] Preferably, the suture spacing of the in-plane suture is 2-4 mm, for example, 2 mm, 3 mm or 4 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] Preferably, the in-plane suture is a single-strand bidirectional suture.

[0032] Preferably, the suture spacing between the layers is 3-6 mm, for example, 3 mm, 4 mm, 5 mm or 6 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the interlayer suture is a double-strand bidirectional suture.

[0034] Preferably, the suture spacing of the overall suture is 4-7 mm, for example, 4 mm, 5 mm, 6 mm or 7 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the overall suturing is performed in a single-strand bidirectional suturing manner.

[0036] In the present invention, by optimally controlling the suture spacing and suture method of in-plane suture, interlayer suture and overall suture, the connection strength and mechanical strength of the preform can be ensured, and the flexibility of manufacturing the fiber preform of complex shape can be further improved.

[0037] Preferably, the suture thread in step S3 comprises polyacrylonitrile-based carbon fiber.

[0038] Preferably, the continuous fiber cloth comprises a pitch-based carbon fiber cloth.

[0039] As a preferred technical solution of the first aspect of the present invention, the preparation method comprises the following steps:

[0040] S1. Preparation of structural unit layer:

[0041] A layer of asphalt-based carbon fiber cloth is compounded with a layer of asphalt-based carbon fiber mesh and a layer of polyacrylonitrile-based carbon fiber mesh to form a first structural unit layer, wherein the thickness ratio of the asphalt-based carbon fiber mesh to the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer is (6-11):5, and the surface density of the asphalt-based carbon fiber cloth is 275-390g / m 2 The asphalt-based carbon fiber mesh tread density is 60-85g / m 2 The surface density of the polyacrylonitrile-based carbon fiber mesh is 35-45g / m 2 ;

[0042] A layer of asphalt-based carbon fiber cloth is compounded with a layer of mixed fiber web to form a second structural unit layer, wherein the surface density of the asphalt-based carbon fiber cloth is 275-390 g / m 2 The mixed fiber web is made by mixing asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber in a mass ratio of (2-5):1 and then undergoing a web-forming process. The surface density of the mixed fiber web is 55-75 g / m 2 ;

[0043] S2. Partitioned layer needling:

[0044] On the forming mold, the first structural unit layer is laid in the area where the lower ring is located and needle-punched layer by layer to a preset thickness, and the second structural unit layer is laid in the area where the ring plate and the upper ring are located and needle-punched layer by layer to a preset thickness, and the needle-punching density is 20-35 needles / cm 2 , the acupuncture depth is 12-16mm;

[0045] S3. Suture:

[0046] Polyacrylonitrile-based carbon fiber is used as a suture line, and the radial joints of the lower ring, the ring plate and the upper ring are located on the same straight line. The suture line is used to perform in-plane suture of the joints in the annular joint area. The in-plane suture includes: suture in the annular joint area of ​​15-30mm on both sides of the joint as the center, the suture spacing is 2-4mm, and the suture method is single-strand bidirectional suture; then interlayer suture is performed to form the main structure, the suture spacing of the interlayer suture is 3-6mm, and the suture method is double-strand bidirectional suture; then asphalt-based carbon fiber cloth is used to be laid on the outer surface of the main structure as a whole and sutured as a whole, the suture spacing of the overall suture is 4-7mm, and the suture method is single-strand bidirectional suture, so as to obtain the guide tube support ring fiber preform.

[0047] In a second aspect, the present invention provides a guide tube support ring fiber preform, wherein the guide tube support ring fiber preform is obtained by the method for preparing the guide tube support ring fiber preform described in the first aspect of the present invention.

[0048] Preferably, the bulk density of the guide tube support ring fiber preform is 0.35-0.55 g / cm 3 , for example, it can be 0.35 g / cm 3 , 0.38g / cm 3 , 0.40g / cm 3 , 0.42g / cm 3 , 0.44g / cm 3 , 0.46g / cm 3 , 0.48g / cm 3 , 0.50g / cm 3 , 0.52g / cm 3 or 0.55g / cm 3 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0049] Preferably, the interlayer density of the guide tube supporting ring fiber preform is 8-12 layers / cm, for example, it can be 8 layers / cm, 9 layers / cm, 10 layers / cm, 11 layers / cm or 12 layers / cm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In a third aspect, the present invention provides a guide tube support ring, wherein the guide tube support ring adopts the guide tube support ring fiber preform described in the second aspect of the present invention as a reinforcement base material.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) In the preparation method provided by the present invention, the structural unit layer is designed according to the performance requirements of different positions of the guide tube support ring, so as to meet the multiple needs of the support ring for heat resistance, thermal insulation and support, so as to ensure stable support and fixation of the guide tube in harsh working environments.

[0053] (2) The present invention designs a first structural unit layer obtained by compounding a three-layer structure including asphalt-based carbon fiber cloth, asphalt-based carbon fiber mesh, and polyacrylonitrile-based carbon fiber mesh, which can effectively give play to the good hardness and modulus of the polyacrylonitrile-based carbon fiber mesh, improve the mechanical strength of the preform, and meet the support needs of the circular ring under the support ring.

[0054] (3) The present invention designs a second structural unit layer composed of asphalt-based carbon fiber cloth and a mixed fiber mesh, and adjusts the doping ratio of the fibers in the mixed fiber mesh, so as to give full play to the heat resistance and thermal insulation of the asphalt-based carbon fiber, improve the damage tolerance of the structure through the interaction of different fibers, enhance the resistance to harsh working environments, and ensure the growth efficiency and quality of the crystals.

[0055] (4) The present invention adopts multiple stitching processes such as in-plane stitching, interlayer stitching and overall stitching, which can enhance the joint strength of the preform, reduce the stress concentration caused by discontinuous fiber arrangement at the joint, reduce the risk of cracks, improve the interlayer bonding force, improve fatigue resistance and life, promote uniform distribution of stress, and improve the integrity and consistency of the preform structure.

[0056] (5) The preparation method provided by the present invention can optimize the use of materials and operation steps, has flexibility in the manufacture of fiber preforms with complex shapes, reduces the overall manufacturing cost, and is conducive to mass production and quality control. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a schematic structural diagram of the fiber preform of the guide tube support ring according to Example 1 of the present invention;

[0058] Among them, 1-upper ring; 2-lower ring; 3-ring plate; 4-joint;

[0059] Figure 2 A schematic diagram of a single-strand bidirectional suturing method used in the in-plane suturing described in Example 1 of the present invention;

[0060] Figure 3 This is a schematic diagram of the double-strand bidirectional suturing method used for interlayer suturing described in Example 1 of the present invention. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0062] Example 1

[0063] This embodiment provides a method for preparing a guide tube support ring fiber preform, the preparation method comprising the following steps:

[0064] S1. Preparation of structural unit layer:

[0065] A layer of asphalt-based carbon fiber cloth is compounded with a layer of asphalt-based carbon fiber mesh and a layer of polyacrylonitrile-based carbon fiber mesh to form a first structural unit layer, wherein the thickness ratio of the asphalt-based carbon fiber mesh to the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer is 6:5, and the surface density of the asphalt-based carbon fiber cloth is 275 g / m 2 The asphalt-based carbon fiber mesh tread density is 60g / m 2 The surface density of the polyacrylonitrile-based carbon fiber mesh is 45g / m 2 ;

[0066] A layer of asphalt-based carbon fiber cloth is compounded with a layer of mixed fiber web to form a second structural unit layer, wherein the surface density of the asphalt-based carbon fiber cloth is 320 g / m 2 The mixed fiber mesh tire is made by mixing asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 3:1 and then undergoing a mesh forming process. The surface density of the mixed fiber mesh tire is 60g / m 2 ;

[0067] S2. Partitioned layer needling:

[0068] On the forming mold, the first structural unit layer is laid in the area where the lower ring is located and needle-punched layer by layer to a preset thickness, and the second structural unit layer is laid in the area where the ring plate and the upper ring are located and needle-punched layer by layer to a preset thickness, and the needle-punching density is 30 needles / cm 2 , the acupuncture depth is 14 mm;

[0069] S3. Suture:

[0070] The polyacrylonitrile-based carbon fiber is used as the stitching line, and the radial joint seams of the lower ring, the ring plate and the upper ring are located on the same straight line. The stitching line is used to perform in-plane stitching of the joint seams in the annular joint area. The in-plane stitching includes: stitching in the annular joint area of ​​16 mm on both sides of the joint seam, and the stitching spacing is 3 mm. Figure 2 As shown, the suturing method is single-strand bidirectional suturing; then interlayer suturing is performed to form the main structure, and the suturing spacing between the interlayer suturing is 4mm, as shown in FIG. Figure 3As shown, the suturing method is double-strand bidirectional suturing; then, asphalt-based carbon fiber cloth (surface density is the same as step S1) is laid on the outer surface of the main structure as a whole and suturing is performed as a whole. The suturing spacing of the overall suturing is 5mm, and the suturing method is single-strand bidirectional suturing to obtain the guide tube support ring fiber preform.

[0071] This embodiment also provides a guide tube support ring fiber preform, such as Figure 1 As shown, the guide tube support ring fiber preform is obtained by the above preparation method, and the guide tube support ring fiber preform comprises an upper ring 1, a ring plate 3 and a lower ring 2 connected in sequence from top to bottom, and the lower ring 2, the ring plate 3 and the upper ring 1 are located on the same straight line in the radial joint 4, and the volume density of the guide tube support ring fiber preform is 0.38g / cm 3 , the interlayer density is 10 layers / cm, the thermal conductivity of the upper ring is 0.1108W / (m·K), the tensile strength of the lower ring is 21.90MPa, and the peel strength of the lower ring is 479N / m.

[0072] This embodiment also provides a guide tube support ring, which is obtained by compounding the guide tube support ring fiber preform as a reinforcement base material.

[0073] Example 2

[0074] This embodiment provides a method for preparing a guide tube support ring fiber preform, the preparation method comprising the following steps:

[0075] S1. Preparation of structural unit layer:

[0076] A layer of asphalt-based carbon fiber cloth is compounded with a layer of asphalt-based carbon fiber mesh and a layer of polyacrylonitrile-based carbon fiber mesh to form a first structural unit layer, wherein the thickness ratio of the asphalt-based carbon fiber mesh to the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer is 8:5, and the surface density of the asphalt-based carbon fiber cloth is 325g / m 2 The asphalt-based carbon fiber mesh tread density is 75g / m 2 The surface density of the polyacrylonitrile-based carbon fiber mesh is 40 g / m 2 ;

[0077] A layer of asphalt-based carbon fiber cloth is compounded with a layer of mixed fiber web to form a second structural unit layer, wherein the surface density of the asphalt-based carbon fiber cloth is 375 g / m 2 The mixed fiber mesh tire is made by mixing asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 5:1 and then undergoing a mesh forming process. The surface density of the mixed fiber mesh tire is 65g / m 2 ;

[0078] S2. Partitioned layer needling:

[0079] On the forming mold, the first structural unit layer is laid in the area where the lower ring is located and needle-punched layer by layer to a preset thickness, and the second structural unit layer is laid in the area where the ring plate and the upper ring are located and needle-punched layer by layer to a preset thickness, and the needle-punching density is 20 needles / cm 2 , the acupuncture depth is 16mm;

[0080] S3. Suture:

[0081] Using polyacrylonitrile-based carbon fiber as a stitching line, the radial joints of the lower circular ring, the ring plate and the upper circular ring are located on the same straight line, and the stitching line is used to perform in-plane stitching of the joints in the annular joint area, and the in-plane stitching includes: stitching in the annular joint area of ​​15 mm on both sides of the joint as the center, the stitching spacing is 4 mm, and the stitching method is single-strand bidirectional stitching; then interlayer stitching is performed to form a main structure, the stitching spacing of the interlayer stitching is 3 mm, and the stitching method is double-strand bidirectional stitching; then asphalt-based carbon fiber cloth (surface density is the same as step S1) is used to lay the outer surface of the main structure in an overall conformal manner and perform overall stitching, the stitching spacing of the overall stitching is 7 mm, and the stitching method is single-strand bidirectional stitching, to obtain the guide tube support ring fiber preform.

[0082] This embodiment also provides a guide tube support ring fiber preform, the guide tube support ring fiber preform is obtained by the above preparation method, and the volume density of the guide tube support ring fiber preform is 0.35g / cm 3 , the interlayer density is 8 layers / cm, the thermal conductivity of the upper ring is 0.1107W / (m·K), the tensile strength of the lower ring is 18.39MPa, and the peel strength of the lower ring is 393N / m.

[0083] This embodiment also provides a guide tube support ring, which is obtained by compounding the guide tube support ring fiber preform as a reinforcement base material.

[0084] Example 3

[0085] This embodiment provides a method for preparing a guide tube support ring fiber preform, the preparation method comprising the following steps:

[0086] S1. Preparation of structural unit layer:

[0087] A layer of asphalt-based carbon fiber cloth is compounded with a layer of asphalt-based carbon fiber mesh and a layer of polyacrylonitrile-based carbon fiber mesh to form a first structural unit layer, wherein the thickness ratio of the asphalt-based carbon fiber mesh to the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer is 11:5, and the surface density of the asphalt-based carbon fiber cloth is 340 g / m 2The asphalt-based carbon fiber mesh tread density is 85g / m 2 The surface density of the polyacrylonitrile-based carbon fiber mesh is 35 g / m 2 ;

[0088] A layer of asphalt-based carbon fiber cloth is compounded with a layer of mixed fiber web to form a second structural unit layer, wherein the surface density of the asphalt-based carbon fiber cloth is 390 g / m 2 The mixed fiber web tire is made by mixing asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 2:1 and then undergoing a web-forming process. The surface density of the mixed fiber web tire is 70g / m 2 ;

[0089] S2. Partitioned layer needling:

[0090] On the forming mold, the first structural unit layer is laid in the area where the lower ring is located and needle-punched layer by layer to a preset thickness, and the second structural unit layer is laid in the area where the ring plate and the upper ring are located and needle-punched layer by layer to a preset thickness, and the needle-punching density is 35 needles / cm 2 , the acupuncture depth is 12 mm;

[0091] S3. Suture:

[0092] Using polyacrylonitrile-based carbon fiber as a suture line, the radial joints of the lower circular ring, the ring plate and the upper circular ring are located on the same straight line, and the suture line is used to perform in-plane suture of the joint in the annular joint area, and the in-plane suture includes: suture in the annular joint area of ​​30 mm on both sides of the joint as the center, the suture spacing is 2 mm, and the suture method is single-strand bidirectional suture; then interlayer suture is performed to form a main structure, the suture spacing of the interlayer suture is 6 mm, and the suture method is double-strand bidirectional suture; then asphalt-based carbon fiber cloth (surface density is the same as step S1) is used to lay the outer surface of the main structure in an overall conformal manner and perform overall suture, the suture spacing of the overall suture is 4 mm, and the suture method is single-strand bidirectional suture, to obtain the guide tube support ring fiber preform.

[0093] This embodiment also provides a guide tube support ring fiber preform, the guide tube support ring fiber preform is obtained by the above preparation method, and the volume density of the guide tube support ring fiber preform is 0.55g / cm 3 , the interlayer density is 12 layers / cm, the thermal conductivity of the upper ring is 0.1177W / (m·K), the tensile strength of the lower ring is 17.94MPa, and the peel strength of the lower ring is 320N / m.

[0094] This embodiment also provides a guide tube support ring, which is obtained by compounding the guide tube support ring fiber preform as a reinforcement base material.

[0095] Comparative Example 1

[0096] This comparative example provides a method for preparing a guide tube support ring fiber preform, and the difference between the preparation method and Example 1 is that no polyacrylonitrile-based carbon fiber web is added to the first structural unit layer.

[0097] The preparation method of the guide tube support ring fiber preform provided in this comparative example cannot be successfully implemented because the asphalt-based carbon fiber has a high modulus and high brittleness, and it is difficult to weave the asphalt-based carbon fiber mesh alone and the size is limited, which cannot meet the molding requirements of the lower ring of the guide tube support ring fiber preform of the present invention.

[0098] Comparative Example 2

[0099] This comparative example provides a method for preparing a guide tube support ring fiber preform, and the difference between the preparation method and Example 1 is that no asphalt-based carbon fiber web is added to the first structural unit layer.

[0100] The present comparative example also provides a guide tube support ring fiber preform, which is obtained by the above-mentioned preparation method. After testing, the tensile strength of the lower ring of the obtained guide tube support ring fiber preform is 26.8MPa, and the peel strength is 512N / m. Although the structural strength of the lower ring is improved compared with that in Example 1, since the use environment of the guide tube support ring fiber preform is a hot field, the lower ring needs to have not only good supporting performance but also meet the requirements of heat resistance and thermal insulation. The lower ring of the present comparative example only adopts polyacrylonitrile-based carbon fiber mesh, which is obviously insufficient in heat resistance and thermal insulation and cannot meet the needs of hot field work.

[0101] Comparative Example 3

[0102] This comparative example provides a method for preparing a guide tube support ring fiber preform. The difference between the preparation method and Example 1 is that the mixed fiber web in the second structural unit layer is replaced with a fiber preform with a surface density of 60 g / m 2 Asphalt based carbon fiber mesh tire.

[0103] The preparation method of the guide tube support ring fiber preform provided in this comparative example cannot be successfully implemented because the asphalt-based carbon fiber has a high modulus and high brittleness, and it is difficult to weave the asphalt-based carbon fiber mesh alone and the size is limited, which cannot meet the molding requirements of the circular ring and the ring plate on the guide tube support ring fiber preform of the present invention.

[0104] Comparative Example 4

[0105] This comparative example provides a method for preparing a guide tube support ring fiber preform. The difference between the preparation method and Example 1 is that the mixed fiber web in the second structural unit layer is replaced with a fiber preform with a surface density of 60 g / m 2 Polyacrylonitrile-based carbon fiber mesh tire.

[0106] This comparative example also provides a guide tube support ring fiber preform, which is obtained by the above-mentioned preparation method. After testing, the thermal conductivity coefficient of the upper ring of the obtained guide tube support ring fiber preform is 0.4897W / (m·K), which is obviously insufficient in heat resistance and thermal insulation compared with the upper ring in Example 1 and cannot meet the needs of thermal field work.

[0107] To sum up, the guide tube support ring fiber preform and its preparation method provided by the present invention can simultaneously ensure the high temperature resistance, thermal insulation and mechanical properties of the guide tube support ring, ensure that the guide tube support ring can stably support and fix the guide tube under harsh working environments, ensure the growth efficiency and quality of the crystal, and are flexible in manufacturing, which is conducive to mass production and quality control.

[0108] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a guide tube support ring fiber preform, characterized in that: The preparation method comprises the following steps: S1. Preparation of structural unit layer: Compounding a layer of asphalt-based carbon fiber cloth with a layer of asphalt-based carbon fiber mesh and a layer of polyacrylonitrile-based carbon fiber mesh to form a first structural unit layer; the thickness ratio of the asphalt-based carbon fiber mesh to the polyacrylonitrile-based carbon fiber mesh in the first structural unit layer is (6-11):5; A layer of asphalt-based carbon fiber cloth is compounded with a layer of mixed fiber web to form a second structural unit layer; the surface density of the mixed fiber web is 55-75g / m 2 The mixed fiber web is made by mixing asphalt-based carbon fiber and polyacrylonitrile-based carbon fiber in a mass ratio of (2-5):1 and then undergoing a web-forming process; S2. Partitioned layer needling: On the forming mold, the first structural unit layer is laid in the area where the lower ring is located and needle-punched layer by layer to a preset thickness, and the second structural unit layer is laid in the area where the ring plate and the upper ring are located and needle-punched layer by layer to a preset thickness; S3. Suture: The butt joint is sutured in the annular butt joint area by using a suture thread, and then the interlayer suture is performed to form a main structure, and then a continuous fiber cloth is laid on the outer surface of the main structure as a whole and sutured as a whole to obtain the guide tube support ring fiber preform; The radial joints of the lower ring, the ring plate and the upper ring are located on the same straight line; The in-plane suturing includes: suturing 15-30 mm circumferential butt joint areas on both sides centered on the butt joint; The suture spacing of the in-plane suture is 2-4 mm; The suturing method of the in-plane suturing is single-strand bidirectional suturing; The suture spacing between the layers is 3-6 mm; The interlayer suture is performed in a double-strand bidirectional suture manner; The suture spacing of the overall suture is 4-7mm; The overall suturing is performed in a single-strand bidirectional suturing manner.

2. The method for preparing the guide tube support ring fiber preform according to claim 1, characterized in that: The surface density of the asphalt-based carbon fiber cloth is 275-390 g / m 2 ; The asphalt-based carbon fiber mesh tread density is 60-85 g / m 2 ; The surface density of the polyacrylonitrile-based carbon fiber mesh is 35-45 g / m 2 .

3. The method for preparing the guide tube support ring fiber preform according to claim 1, characterized in that: The acupuncture density in step S2 is 20-35 needles / cm 2 ; The depth of the acupuncture is 12-16 mm.

4. The method for preparing a guide tube support ring fiber preform according to claim 1, characterized in that: The suture thread in step S3 comprises polyacrylonitrile-based carbon fiber; The continuous fiber cloth includes a pitch-based carbon fiber cloth.

5. A guide tube support ring fiber preform, characterized in that: The guide tube support ring fiber preform is obtained by the preparation method of the guide tube support ring fiber preform according to any one of claims 1 to 4.

6. The guide tube support ring fiber preform according to claim 5, characterized in that: The bulk density of the guide tube support ring fiber preform is 0.35-0.55 g / cm 3 ; The interlayer density of the guide tube support ring fiber preform is 8-12 layers / cm.

7. A guide tube support ring, characterized in that: The guide tube support ring adopts the guide tube support ring fiber preform described in claim 5 or 6 as a reinforcement base material.

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