Continuous yarn for winding forming and production process and application thereof

Abstract

The invention belongs to the technical field of processing of high-performance fiber materials and composite materials of the high-performance fiber materials, and relates to a continuous yarn for winding forming and a production process and application of the continuous yarn. The production process comprises a mixed opening process, a carding process, a sizing process, a furling process, a drawing process and a twisting process. One sizing process is adopted, and a spraying method is adopted; or, the first sizing process adopts a spraying method, and the second sizing process adopts an impregnation method; drying is carried out while folding is carried out; the continuous yarn for winding forming is prepared by adopting the production process. The application method comprises the following steps: impregnating a resin matrix with continuous yarns for winding forming, winding the continuous yarns on a core mold, heating, curing and forming, cooling and demolding to obtain the unidirectional fiber winding reinforced composite material. The non-continuous high-performance fiber is successfully prepared into the continuous yarn for winding forming through an innovative sizing process, the application limitation of the non-continuous high-performance fiber is solved, and high-value recycling of the high-performance fiber is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of processing high-performance fiber materials and composite materials thereof, and relates to a continuous yarn for winding and molding, and a production process and application thereof. Background Art

[0002] High-performance fibers represented by carbon fibers have excellent properties such as high specific strength, high specific modulus, and corrosion resistance. Their physical properties are superior to traditional metal materials in many aspects. They are widely used in aviation, energy, transportation, construction, military and other fields, and are an important component of advanced composite materials. However, the production process of high-performance fibers consumes a lot of energy. Recycling and reusing them can not only reduce energy consumption and manufacturing costs, but also give full play to the mechanical properties of recycled fibers. However, due to the limitations of the recycling process, the recycled high-performance fibers are usually in a discontinuous form. Since discontinuous high-performance fibers are not suitable for the molding process of continuous fiber-reinforced resin-based composites, including winding molding, their application value is severely limited, and the performance advantages of high-performance fibers cannot be fully utilized. Therefore, it is urgent to explore a process method to make discontinuous high-performance fibers into continuous yarns, and then use the winding process for molding, so as to realize the high-value application of discontinuous high-performance fibers and turn waste into treasure.

[0003] In order to make the discontinuous high-performance fiber into a continuous yarn, the discontinuous high-performance fiber and the thermoplastic resin fiber can be blended into yarn (the blended yarn is recorded as blended yarn X). During the preparation of the yarn, the fibers will separate and rearrange, and the adhesion between the fibers will directly lead to fiber breakage during the combing process, which will reduce the fiber length in the yarn and increase the content of impurities such as cotton knots, resulting in poor quality of the yarn. Therefore, when preparing the yarn, before combing, the surface of the discontinuous high-performance fiber needs to be desized and kept clean to ensure the smooth formation of the yarn. However, the clean surface of the discontinuous high-performance fiber after removing the surface sizing is chemically inert. If this type of surface-treated high-performance fiber and the product prepared therefrom are directly used to reinforce the winding molding composite material sample of the thermosetting resin matrix, the poor interface bonding performance between the fiber and the thermosetting resin matrix will result in insufficient performance of the sample, which cannot meet the current product requirements of the winding molding composite material sample. Therefore, it is necessary to adopt a suitable surface modification process to treat the combed fiber, that is, the blended yarn X.

[0004] Sizing is a common surface modification process that can form a layer of organic matter on the fiber surface to improve the bonding effect between the fiber and the resin. Compared with other surface modification processes such as plasma treatment and chemical grafting, the sizing process has the advantages of simple process, low cost, fiber protection, improved processing performance, and easier industrial application.

[0005] There are existing technologies for sizing continuous high-performance fibers, but it is difficult to apply these technologies to sizing blended yarn X for the following reasons:

[0006] At present, the sizing technology of continuous high-performance fibers includes traditional impregnation, distributed sizing and spray sizing (CN213357961U) and other methods. These methods all use a certain tension to apply to the continuous high-performance fibers to flatten them and then perform continuous sizing. The specific process is: after applying tension to flatten the continuous high-performance fiber tow, it is immersed in the sizing liquid in the dipping tank, or the atomized sizing liquid is sprayed on the fiber surface to fully infiltrate the fiber tow with the sizing liquid. After the fiber tow leaves the dipping tank, the excess sizing liquid is removed by a scraper or a rubber roller to control the sizing rate, and finally dried.

[0007] However, in the sizing process of continuous high-performance fibers, the fibers need to be flattened by tension to achieve uniform sizing. However, when the product to be sized is a blended yarn X, its structure is formed by the entanglement and overlap of non-continuous high-performance fibers, which cannot be flattened by tension. If the blended yarn X is sized according to the sizing process of continuous high-performance fibers, the applied tension will destroy the overall structure of the yarn, resulting in the loosening and damage of the fiber yarn and the unwrapped fiber roving structure, which is very easy to break the yarn or break the strip.

[0008] The prior art has sizing for blended yarns other than blended yarn X (the blended yarn is denoted as blended yarn Y), but it is difficult to sizing for blended yarn X by referring to these technologies for the following reasons:

[0009] At present, the sizing technology of blended yarn Y includes solution impregnation method, foam sizing method and sizing extrusion method (CN117535897A), etc. These processes are mature and stable. These methods are all for sizing the yarn after twisting and forming. The specific process is: immersing the twisted yarn in sizing liquid or sizing foam, or using a roller to bring up the sizing liquid and then apply it to the twisted yarn, and then drying to complete the sizing. The purpose of sizing the blended yarn Y is to improve the wear resistance of the yarn, so that the sizing liquid penetrates into the yarn to increase the breaking strength, and prevent the yarn from breaking or pilling in the subsequent textile process. Therefore, the sizing rate is generally controlled at 6% to 12%. The primary purpose of sizing the blended yarn X is to improve the interface performance between the resin matrix and the non-continuous high-performance fiber, and it has a greater impact on the interface performance. The sizing rate is generally below 3%, and it needs to be accurately controlled to one decimal place of the percentage. Its sizing accuracy is much higher than the sizing accuracy of other blended yarns. Since there are large differences in sizing rate and sizing accuracy between blended yarn X and blended yarn Y, the sizing process of blended yarn Y cannot be directly applied to blended yarn X.

[0010] Therefore, it is necessary to study a sizing process for blended yarn X. Summary of the invention

[0011] The purpose of the present invention is to solve the problems existing in the prior art, to provide a sizing process for blended yarn X, and to obtain a production process for continuous yarn for winding molding with discontinuous high-performance fibers and thermoplastic resin fibers as main raw materials, and further, to apply the obtained continuous yarn for winding molding to the winding field.

[0012] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0013] A production process for continuous yarn for winding and forming, comprising a mixing and opening process, a combing process, a gathering process, a drawing process, and a twisting process;

[0014] Mixed opening refers to the opening of discontinuous high-performance fibers and thermoplastic resin fibers after mixing. The surface of the discontinuous high-performance fibers is free of slurry. The opening method is not limited. The airflow-assisted free opening method can be used. The airflow generated by the fan rolls in the mixing chamber, and the opening roller is combined to loosen the fibers and improve the fluffiness of the fiber mixture.

[0015] During the carding process, the discontinuous high-performance fibers and thermoplastic resin fibers are combed by the cylinder and the working roller in the carding machine to form a mesh structure attached to the roller, and then stripped from the doffer by the cotton stripping knife to obtain a continuous and uniform single-layer fiber yarn.

[0016] Drawing can further improve the orientation and uniformity of non-continuous high-performance fibers in the yarn, and reduce the yarn fineness to a level close to the required yarn linear density, such as Figure 3 and Figure 4 As shown in the figure, the arrangement direction of the black carbon fibers inside the yarn before and after drawing is improved from a messy state to an arrangement along the transverse fiber yarn direction. In addition, by adjusting the drawing process parameters, the thickness of the yarn after drawing can be controlled, thereby controlling the fineness of the final yarn. The number of drawing times can be increased depending on the product status.

[0017] Twisting can tighten the loose fibers together to form a strong rope-like yarn structure;

[0018] It also includes the sizing process;

[0019] The sizing process is a single process, located between the carding process and the gathering process, using a spray method (i.e. using a high-pressure atomizing nozzle to spray the sizing liquid onto the yarn net formed by carding); the sizing rate is equal to the set sizing rate, which is not higher than 3%;

[0020] The timing and method of sizing are very important. If sizing is performed before combing, no matter what sizing method is used, it will cause adhesion between fibers, causing them to break and other damage during the combing process; if sizing is performed by spraying after twisting, since the sizing liquid stays on the surface of the yarn, it is necessary to rely on rubber squeezing rollers to squeeze the sizing liquid further into the fibers, which will cause damage to the fiber and yarn structure; if sizing is performed by dipping after twisting, since the yarn will inevitably be affected by factors such as tension and liquid resistance during the process of entering and exiting the sizing liquid, the yarn structure is prone to damage. At the same time, sizing the twisted yarn will also cause uneven sizing and difficulty in accurately controlling the sizing rate due to the complex internal structure of the yarn;

[0021] The present invention adopts a spraying method for sizing between the combing process and the gathering process. At this time, the sizing liquid can easily penetrate between the fibers without relying on the rubber squeezing roller for squeezing, which can avoid damage to the fiber and yarn structure, and can make the sizing agent fully and evenly penetrate into the yarn under the premise of low loss or no loss;

[0022] Drying is also carried out while gathering;

[0023] The mechanical properties of the molded board obtained by compression molding the gathered yarn strips with epoxy resin are significantly better than those of the molded board obtained without sizing process. It can be seen that the surface modification of the yarn inside and outside can be completed uniformly by spraying sizing between the combing process and the gathering process.

[0024] As the preferred technical solution:

[0025] In the production process of continuous yarn for winding molding as described above, the concentration of the sizing liquid used for sizing is 3.5-6.5wt%, so as to ensure the uniformity of sizing of the entire yarn mesh, and the viscosity is 15-45mPa·s, so that it can fully penetrate into the fiber gaps in the yarn mesh and form a sizing layer, and the spraying rate is positively correlated with the combing speed.

[0026] In the production process of a continuous yarn for winding molding as described above, the average length of the discontinuous high-performance fiber is 40-200 mm, and the discontinuous high-performance fiber is a commonly used resin-based composite reinforcement such as glass fiber, carbon fiber, basalt fiber or boron fiber; the average length of the thermoplastic resin fiber is the same as the discontinuous high-performance fiber to ensure uniform fiber mixing after opening, and the thermoplastic resin fiber is PA fiber, PET fiber, PP fiber, PEEK fiber or PPS fiber; the mass ratio of the discontinuous high-performance fiber to the thermoplastic resin fiber is not limited.

[0027] As described above, in the production process of continuous yarn for winding molding, an opener is used for mixed opening, the feeding speed is 0.5-2.0 m / min, and the opening beater speed is 800-1500 rpm; a carding machine is used for carding, the cylinder speed is 100-400 rpm, the doffer speed is 50-200 rpm, and the feeding speed is 0.3-1.5 m / min; a drawing machine is used for drawing, the drafting ratio is 1.5-3.0, and the drawing speed is 50-150 m / min; when twisting, the twist is set to 20-40 T / m, and the winding tension is 5-15 cN; the fineness of the yarn obtained by gathering is 2383-4873 tex, and the fineness of the yarn formed by twisting is 426.3-488.3 tex.

[0028] The present invention also provides another production process of continuous yarn for winding and forming, including a mixing and opening process, a combing process, a gathering process, a drawing process, and a twisting process;

[0029] Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them. The surface of the discontinuous high-performance fibers is free of slurry.

[0030] It also includes the sizing process;

[0031] There are two sizing processes. The first sizing process is located between the combing process and the gathering process, and adopts the spray method (i.e., the sizing liquid is sprayed on the yarn net formed by combing with a high-pressure atomizing nozzle). The second sizing process is located after the twisting process, and adopts the dipping method (i.e., the yarn is dipped in the sizing liquid, taken out, and dried). The sizing agent used in the two sizing processes is the same. The sizing rate of the first sizing process is 60-75% of the set sizing rate. The total sizing rate of the two sizing processes is equal to the set sizing rate, and the set sizing rate is not higher than 3%;

[0032] The clothes are dried at the same time as they are gathered.

[0033] Regardless of whether the sizing process is one or two steps, the spray method can be used for sizing between the carding process and the gathering process to complete the uniform surface modification of the inside and outside of the yarn. The advantage of two steps over one step is that the finishing quality of the continuous yarn for winding can be improved, the amount of hairiness on the surface of the continuous yarn for winding can be reduced, the wear resistance and cohesion of the continuous yarn for winding can be improved, and the flexibility of the yarn can be maintained.

[0034] As the preferred technical solution:

[0035] In the production process of continuous yarn for winding molding as described above, the concentration of the sizing liquid used in the first sizing is 3.5-6.5wt%, so as to ensure the uniformity of the overall sizing of the yarn mesh, and the viscosity is 15-45mPa·s, so that it can fully penetrate into the fiber gaps in the yarn mesh and form a sizing layer, and the spraying rate is positively correlated with the combing speed; the concentration of the sizing liquid used in the second sizing is 1.0-2.5wt%, so as to reduce the yarn hairiness, form a wear-resistant layer, and maintain the flexibility of the yarn, and the viscosity is 2-10mPa·s; during the second sizing, the immersion temperature is 35-60℃, and the immersion time is 5-20s.

[0036] The production process of a continuous yarn for winding molding as described above also includes a wrapping process located between the twisting process and the second sizing process, and the wrapping is to wrap the continuous fiber around the twisted yarn; the wrapping can improve the strength, uniformity and wear resistance of the yarn. If the second sizing is performed directly after twisting and ends after the second sizing, then the obtained continuous yarn for winding molding cannot guarantee that it can always withstand greater tension.

[0037] As described above, in the production process of continuous yarn for winding molding, the continuous fiber is a small-tow continuous fiber with a fineness of 20-150D, and the optional fibers include carbon fiber, glass fiber and various organic fibers, which are selected according to the process requirements; during winding, the winding speed is 50-200m / min, the winding angle is 15-35°, the winding tension is 5-20cN, and the winding twist is 200-800T / m.

[0038] The present invention also provides a continuous yarn for winding and forming, which is produced by using the production process of a continuous yarn for winding and forming as described in any one of the above items.

[0039] The present invention also provides an application of the continuous yarn for winding molding as described above, wherein the continuous yarn for winding molding is impregnated with a resin matrix and then wound onto a core mold, and then heated and cured and molded, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

[0040] The continuous yarn for winding molding produced by the present invention can be applied to the winding field. In the winding process structure with low load-bearing capacity and low requirements, the continuous yarn for winding molding is used to replace the continuous long fiber for winding molding, thereby solving the problem that the non-continuous high-performance fiber in the prior art has low utilization value and is difficult to be applied to high-performance structural parts. At the same time, it provides higher designability for the winding process and reduces the preparation cost and carbon emissions of the winding process. The continuous yarn for winding molding contains thermoplastic resin fibers, which is beneficial to improving the interlayer toughness and impact resistance of the product; in addition, the continuous yarn for winding molding is applied to winding, with a high degree of process automation, labor saving, and high raw material utilization, which can maximize the value of the continuous yarn for winding molding.

[0041] Beneficial effects:

[0042] (1) The present invention sprays sizing on non-continuous high-performance fibers between the carding process and the gathering process, thereby avoiding damage to the fiber and yarn structure, achieving uniform surface modification inside and outside the yarn net with low or no damage, improving the interface performance between the high-performance fibers in the yarn and the resin matrix in the subsequent molding process, improving the overall mechanical properties of the continuous yarn for winding molding, and expanding the use value and application range of the continuous yarn products for winding molding;

[0043] (2) The present invention performs sizing on the continuous yarn for winding and forming after the twisting process, which can improve the finishing quality of the continuous yarn for winding and forming, reduce the amount of hairiness on the surface of the continuous yarn for winding and forming, improve the wear resistance and cohesion of the continuous yarn for winding and forming, and maintain the flexibility of the yarn;

[0044] (3) The fiber type, fiber content and fineness of the continuous yarn for winding molding of the present invention can be controlled;

[0045] (4) By subjecting the discontinuous high-performance fibers to specific processes such as opening, combing, gathering, drawing, twisting, etc., the present invention greatly improves the orientation and uniformity of the discontinuous high-performance fibers in the continuous yarn for winding, so that the yarn product has excellent modulus performance, thereby effectively improving the application value of the discontinuous high-performance fibers;

[0046] (5) The continuous yarn for winding molding of the present invention has low preparation cost and excellent modulus performance, and can be used in the winding field to replace components with lower load-bearing requirements in the winding process, thereby achieving cost reduction, improving toughness and having structural designability, greatly improving the application value of non-continuous high-performance fibers;

[0047] (6) By using continuous yarn for winding molding for winding molding, thermoplastic resin fibers are introduced into the winding molded parts. After the winding product is cured, the thermoplastic resin is dissolved in the resin matrix along the interlayer direction, achieving a toughening effect, fully improving the interlayer fracture toughness of the winding product, and broadening the application of continuous yarn for winding molding in the winding field. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a physical picture of the continuous yarn for winding molding prepared in Example 4;

[0049] Figure 2 This is a physical picture of the continuous yarn for winding molding prepared in Example 3;

[0050] Figure 3 This is the super depth of field image of the yarn obtained by gathering in Example 3, with a resolution of 1471×1099;

[0051] Figure 4 This is a super depth of field image of the yarn obtained by drawing in Example 3, with a resolution of 1471×1099. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0053] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0054] Viscosity: Tested in accordance with GB / T 22235-2008 standard.

[0055] 0° tensile strength, 0° tensile modulus: tested in accordance with ISO527-5:2021 standard.

[0056] 0° compression strength, 0° compression modulus: tested in accordance with ISO14126:2023 standard.

[0057] 0° flexural strength, 0° flexural modulus: tested in accordance with ISO14125:1998 standard.

[0058] Fiber mass content, fiber volume content: The unidirectional fiber wound reinforced composite materials prepared in Examples 1-3 were tested according to ISO 14127:2024, the unidirectional fiber wound reinforced composite materials prepared in Examples 4-5 were tested according to ISO1172:2023, and the molded plates obtained by compression molding the yarns obtained by gathering in Example 5 and Comparative Example 1 with epoxy resin were tested according to ISO 1172:2023.

[0059] Density: Tested according to ISO1183-1:2019.

[0060] Tensile strength, tensile modulus, fiber tensile strength, fiber tensile modulus: tested in accordance with GB / T 1458-2023, where the loading speed is 2 mm / min.

[0061] Example 1

[0062] A method for preparing a unidirectional fiber-wound reinforced composite material, the specific steps are as follows:

[0063] (1) Preparation of raw materials;

[0064] Non-continuous high-performance fiber: carbon fiber, the manufacturer is Toray Industries, the brand is T700, the average length is 120mm;

[0065] Thermoplastic resin fiber: PA56 fiber, manufactured by Shanghai Cathay Biotechnology Co., Ltd., brand T-1105, average length 120 mm;

[0066] Sizing liquid A: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 3.5wt%, and the viscosity is 15mPa·s;

[0067] Sizing liquid B: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 2.5wt%, and the viscosity is 10mPa·s;

[0068] Continuous fiber: small tow continuous fiber with a fineness of 150D;

[0069] Resin matrix: epoxy resin, the manufacturer is Shangwei New Materials Technology Co., Ltd., the brand is EzCicloRB241;

[0070] (2) Preparation of continuous yarn for winding;

[0071] The production process of continuous yarn for winding is: mixing and opening → combing → first sizing → gathering → drawing → twisting → wrapping → second sizing;

[0072] Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them with an opening machine. The mass ratio of discontinuous high-performance fibers to thermoplastic resin fibers is 2:1, the feeding speed is 0.5m / min, and the opening beater speed is 800rpm.

[0073] The carding machine was used for carding, with the cylinder speed of 100rpm, the doffer speed of 50rpm, and the feeding speed of 0.3m / min;

[0074] The first sizing process uses sizing liquid A and adopts the spray method. The sizing rate of the first sizing process is 60% of the set sizing rate. The second sizing process uses sizing liquid B and adopts the immersion method. The immersion temperature is 35°C and the immersion time is 20s. The total sizing rate of the two sizing processes is equal to the set sizing rate, which is 1.7%;

[0075] The yarn is dried while being gathered; the fineness of the gathered yarn is 2383tex;

[0076] The drawing machine is used for drawing, with a drafting ratio of 1.5 and a drawing speed of 50m / min;

[0077] During twisting, the twist was set to 20T / m, the winding tension was 5cN, and the fineness of the twisted yarn was 488.3tex;

[0078] Wrapping is to wrap the continuous fiber on the twisted yarn, with a wrapping speed of 50m / min, a wrapping angle of 15°, a wrapping tension of 15cN, and a wrapping twist of 200T / m;

[0079] (3) Preparation of unidirectional fiber winding reinforced composite materials;

[0080] After the continuous yarn for winding molding is impregnated with a resin matrix, it is wound (the relevant process parameters are set in accordance with GB / T 1458-2023 standard) onto a core mold, and then heated and cured, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

[0081] The final unidirectional fiber winding reinforced composite material has a fiber mass content of 48.21%, a fiber volume content of 38.29%, a fiber tensile strength of 936.80 MPa, a fiber tensile modulus of 142.20 GPa, and a density of 1.38 g / cm 3 , the tensile strength is 358.70MPa and the tensile modulus is 54.45GPa.

[0082] Example 2

[0083] A method for preparing a unidirectional fiber-wound reinforced composite material, the specific steps are as follows:

[0084] (1) Preparation of raw materials;

[0085] Non-continuous high-performance fiber: carbon fiber, the manufacturer is Toray Industries, the brand is T700, the average length is 120mm;

[0086] Thermoplastic resin fiber: PA56 fiber, manufactured by Shanghai Cathay Biotechnology Co., Ltd., brand T-1105, average length 120 mm;

[0087] Sizing liquid A: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 6.5wt%, and the viscosity is 45mPa·s;

[0088] Sizing liquid B: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 1.0wt%, and the viscosity is 2mPa·s;

[0089] Continuous fiber: small tow continuous fiber with a fineness of 60D;

[0090] Resin matrix: epoxy resin, the manufacturer is Shangwei New Materials Technology Co., Ltd., the brand is EzCicloRB241;

[0091] (2) Preparation of continuous yarn for winding;

[0092] The production process of continuous yarn for winding is: mixing and opening → combing → first sizing → gathering → drawing → twisting → wrapping → second sizing;

[0093] Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them with an opening machine. The mass ratio of discontinuous high-performance fibers to thermoplastic resin fibers is 3:1, the feeding speed is 1m / min, and the opening beater speed is 1200rpm.

[0094] The carding machine is used for carding, with the cylinder speed of 250rpm, the doffer speed of 150rpm, and the feeding speed of 0.7m / min;

[0095] The first sizing process uses sizing liquid A and adopts the spray method. The sizing rate of the first sizing process is 70% of the set sizing rate. The second sizing process uses sizing liquid B and adopts the immersion method. The immersion temperature is 60°C and the immersion time is 5s. The total sizing rate of the two sizing processes is equal to the set sizing rate, which is 1.7%;

[0096] The yarn is dried while being gathered; the fineness of the yarn obtained by gathering is 4247tex;

[0097] The drawing machine is used for drawing, the drafting ratio is 3, and the drawing speed is 120m / min;

[0098] During twisting, the twist was set to 30T / m, the winding tension was 12cN, and the fineness of the twisted yarn was 476.2tex;

[0099] Wrapping is to wrap the continuous fiber on the twisted yarn, with a wrapping speed of 150m / min, a wrapping angle of 25°, a wrapping tension of 20cN, and a wrapping twist of 800T / m;

[0100] (3) Preparation of unidirectional fiber winding reinforced composite materials;

[0101] After the continuous yarn for winding molding is impregnated with a resin matrix, it is wound (the relevant process parameters are set in accordance with GB / T 1458-2023 standard) onto a core mold, and then heated and cured, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

[0102] The final unidirectional fiber winding reinforced composite material has a fiber mass content of 45.12%, a fiber volume content of 35.40%, a fiber tensile strength of 1025.26MPa, a fiber tensile modulus of 151.98GPa, and a density of 1.41g / cm 3 , the tensile strength is 372.50MPa and the tensile modulus is 53.80GPa.

[0103] Example 3

[0104] A method for preparing a unidirectional fiber-wound reinforced composite material, the specific steps are as follows:

[0105] (1) Preparation of raw materials;

[0106] Non-continuous high-performance fiber: carbon fiber, the manufacturer is Toray Industries, the brand is T700, the average length is 80mm;

[0107] Thermoplastic resin fiber: PA56 fiber, manufactured by Shanghai Cathay Biotechnology Co., Ltd., brand name T-1105, average length 80 mm;

[0108] Sizing liquid A: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 6.0wt%, and the viscosity is 37mPa·s;

[0109] Sizing liquid B: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 1.0wt%, and the viscosity is 2mPa·s;

[0110] Continuous fiber: small tow continuous fiber with a fineness of 20D;

[0111] Resin matrix: epoxy resin, the manufacturer is Shangwei New Materials Technology Co., Ltd., the brand is EzCicloRB241;

[0112] (2) Preparation of continuous yarn for winding;

[0113] The production process of continuous yarn for winding is: mixing and opening → combing → first sizing → gathering → drawing → twisting → wrapping → second sizing;

[0114] Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them with an opening machine. The mass ratio of discontinuous high-performance fibers to thermoplastic resin fibers is 3:1, the feeding speed is 1m / min, and the opening beater speed is 1200rpm.

[0115] The carding machine is used for carding, with the cylinder speed of 250rpm, the doffer speed of 150rpm, and the feeding speed of 0.7m / min;

[0116] The first sizing process uses sizing liquid A and adopts the spray method. The sizing rate of the first sizing process is 70% of the set sizing rate. The second sizing process uses sizing liquid B and adopts the immersion method. The immersion temperature is 60°C and the immersion time is 10s. The total sizing rate of the two sizing processes is equal to the set sizing rate, which is 1.7%;

[0117] The yarn is dried while being gathered. The fineness of the gathered yarn is 4620 tex. The ultra-depth image of the gathered yarn is as follows: Figure 3 As shown;

[0118] The drawing machine is used for drawing, the drafting ratio is 3, the drawing speed is 120m / min, and the super depth of field image of the yarn obtained by drawing is as follows Figure 4 As shown;

[0119] During twisting, the twist was set to 30T / m, the winding tension was 12cN, and the fineness of the twisted yarn was 426.3tex;

[0120] Wrapping is to wrap the continuous fiber on the twisted yarn, with a wrapping speed of 150m / min, a wrapping angle of 25°, a wrapping tension of 20cN, and a wrapping twist of 800T / m;

[0121] The obtained continuous yarn for winding molding is as follows Figure 2 As shown;

[0122] (3) Preparation of unidirectional fiber winding reinforced composite materials;

[0123] After the continuous yarn for winding molding is impregnated with a resin matrix, it is wound (the relevant process parameters are set in accordance with GB / T 1458-2023 standard) onto a core mold, and then heated and cured, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

[0124] The final unidirectional fiber winding reinforced composite material has a fiber mass content of 46.87%, a fiber volume content of 37.03%, a fiber tensile strength of 1056.85MPa, a fiber tensile modulus of 137.27GPa, and a density of 1.35g / cm 3 , the tensile strength is 391.35MPa and the tensile modulus is 50.83GPa.

[0125] Example 4

[0126] A method for preparing a unidirectional fiber-wound reinforced composite material, the specific steps are as follows:

[0127] (1) Preparation of raw materials;

[0128] Non-continuous high-performance fiber: glass fiber, the manufacturer is Zhejiang Hengshi Jiye Co., Ltd., the brand is E8-UD1250, the average length is 80mm;

[0129] Thermoplastic resin fiber: PA56 fiber, manufactured by Shanghai Cathay Biotechnology Co., Ltd., brand name T-1105, average length 80 mm;

[0130] Sizing liquid A: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 6.0wt%, and the viscosity is 37mPa·s;

[0131] Sizing liquid B: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 2.0wt%, and the viscosity is 6mPa·s;

[0132] Continuous fiber: small tow continuous fiber with a fineness of 20D;

[0133] Resin matrix: epoxy resin, the manufacturer is Shangwei New Materials Technology Co., Ltd., the brand is EzCicloRB241;

[0134] (2) Preparation of continuous yarn for winding;

[0135] The production process of continuous yarn for winding is: mixing and opening → combing → first sizing → gathering → drawing → twisting → wrapping → second sizing;

[0136] Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them with an opening machine. The mass ratio of discontinuous high-performance fibers to thermoplastic resin fibers is 9:1, the feeding speed is 2m / min, and the opening beater speed is 1500rpm.

[0137] The carding machine is used for carding, with the cylinder speed of 400rpm, the doffer speed of 200rpm, and the feeding speed of 1.5m / min;

[0138] The first sizing process uses sizing liquid A and adopts the spray method. The sizing rate of the first sizing process is 75% of the set sizing rate. The second sizing process uses sizing liquid B and adopts the immersion method. The immersion temperature is 50°C and the immersion time is 20s. The total sizing rate of the two sizing processes is equal to the set sizing rate, which is 2.8%;

[0139] The yarn is dried while being gathered; the fineness of the gathered yarn is 4829tex;

[0140] The drawing machine is used for drawing, the drafting ratio is 2, and the drawing speed is 150m / min;

[0141] During twisting, the twist was set to 40T / m, the winding tension was 15cN, and the fineness of the twisted yarn was 453.2tex;

[0142] Wrapping is to wrap the continuous fiber on the twisted yarn, with a wrapping speed of 200m / min, a wrapping angle of 35°, a wrapping tension of 5cN, and a wrapping twist of 600T / m;

[0143] The obtained continuous yarn for winding molding is as follows Figure 1 As shown;

[0144] (3) Preparation of unidirectional fiber winding reinforced composite materials;

[0145] After the continuous yarn for winding molding is impregnated with a resin matrix, it is wound (the relevant process parameters are set in accordance with GB / T 1458-2023 standard) onto a core mold, and then heated and cured, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

[0146] The final unidirectional fiber winding reinforced composite material has a fiber mass content of 50.78%, a fiber volume content of 32.09%, a fiber tensile strength of 832.69 MPa, a fiber tensile modulus of 53.29 GPa, and a density of 1.52 g / cm 3 , the tensile strength is 267.21MPa and the tensile modulus is 17.10GPa.

[0147] Example 5

[0148] A method for preparing a unidirectional fiber-wound reinforced composite material, the specific steps are as follows:

[0149] (1) Preparation of raw materials;

[0150] Non-continuous high-performance fiber: glass fiber, the manufacturer is Zhejiang Hengshi Jiye Co., Ltd., the brand is E8-UD1250, the average length is 80mm;

[0151] Thermoplastic resin fiber: PA56 fiber, manufactured by Shanghai Cathay Biotechnology Co., Ltd., brand name T-1105, average length 80 mm;

[0152] Sizing liquid A: the solute is sizing agent (manufacturer is Changsha Xindehang Chemical Co., Ltd., brand MH-681), the solvent is deionized water, the concentration is 6.0wt%, and the viscosity is 37mPa·s;

[0153] Continuous fiber: small tow continuous fiber with a fineness of 20D;

[0154] Epoxy resin A: The manufacturer is SWANCOR New Materials Technology Co., Ltd., the brand is SWANCOR 2554-K;

[0155] Resin matrix: Epoxy resin B, manufacturer is Shangwei New Materials Technology Co., Ltd., brand name is EzCicloRB241;

[0156] (2) Preparation of continuous yarn for winding;

[0157] The production process of continuous yarn for winding is: mixing and opening → combing → sizing → gathering → drawing → twisting → wrapping;

[0158] Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them with an opening machine. The mass ratio of discontinuous high-performance fibers to thermoplastic resin fibers is 9:1, the feeding speed is 2m / min, and the opening beater speed is 1500rpm.

[0159] The carding machine is used for carding, with the cylinder speed of 400rpm, the doffer speed of 200rpm, and the feeding speed of 1.5m / min;

[0160] The sizing process uses sizing liquid A and adopts a spray method. The sizing rate of the sizing process is a set sizing rate, and the set sizing rate is 2.8%;

[0161] The yarn was dried while being gathered; the fineness of the gathered yarn was 4873 tex; the thickness of the molded plate obtained by compression molding the gathered yarn with epoxy resin A was 2.6 mm, the fiber mass content was 69.55%, the fiber volume content was 51.13%, and the density was 1.916 g / cm 3 , 0° tensile strength is 236MPa, 0° tensile modulus is 30.8GPa, 0° compressive strength is 451MPa, 0° compression modulus is 31.4GPa, 0° bending strength is 415MPa, 0° bending modulus is 35.6GPa; the specific process of compression molding is: the gathered yarn strips are laid side by side in the same direction into layers, epoxy resin A is laid between the layers and then placed in the mold, and then the mold is placed in a flat vulcanizer, preheated at 80℃ for 30min under a pressure of 40T, pressurized to 150T and heated for curing molding, cooled and demolded to obtain a molded plate;

[0162] The drawing machine is used for drawing, the drafting ratio is 2, and the drawing speed is 150m / min;

[0163] During twisting, the twist was set to 40T / m, the winding tension was 15cN, and the fineness of the twisted yarn was 453.2tex;

[0164] Wrapping is to wrap the continuous fiber on the twisted yarn, with a wrapping speed of 200m / min, a wrapping angle of 35°, a wrapping tension of 5cN, and a wrapping twist of 600T / m;

[0165] (3) Preparation of unidirectional fiber winding reinforced composite materials;

[0166] After the continuous yarn for winding molding is impregnated with a resin matrix, it is wound (the relevant process parameters are set in accordance with GB / T 1458-2023 standard) onto a core mold, and then heated and cured, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

[0167] The final unidirectional fiber winding reinforced composite material has a fiber mass content of 41.12%, a fiber volume content of 24.23%, a fiber tensile strength of 1123.40MPa, a fiber tensile modulus of 61.08GPa, and a density of 1.462g / cm 3 , the tensile strength is 272.20MPa and the tensile modulus is 14.80GPa.

[0168] Comparative Example 1

[0169] The same as Example 5, except that the sizing process is not performed; the thickness of the molded plate obtained by molding the gathered yarn strips with epoxy resin A is 2.9 mm, the fiber mass content is 70.62%, the fiber volume content is 52.40%, and the density is 1.828 g / cm 3 , 0° tensile strength is 205MPa, 0° tensile modulus is 28.1GPa, 0° compressive strength is 395MPa, 0° compression modulus is 28.2GPa, 0° flexural strength is 313MPa, and 0° flexural modulus is 24.7GPa.

[0170] Compared with Example 1, when the fiber volume content in the composite material is similar, the mechanical properties of the molded plate obtained by compression molding the gathered yarn strips with epoxy resin A are significantly better than those of Comparative Example 1, wherein the 0° tensile strength is increased by 15.12%, the 0° tensile modulus is increased by 9.61%, the 0° compressive strength is increased by 14.18%, the 0° compression modulus is increased by 11.35%, the 0° bending strength is increased by 32.59%, and the 0° bending modulus is increased by 44.13%. It can be seen that the spray method can be used for sizing between the combing process and the gathering process to complete the uniform surface modification of the inside and outside of the yarn.

Claims

1. A production process for continuous yarn for winding, comprising a mixing and opening process, a combing process, a gathering process, a drawing process, and a twisting process; Mixed opening refers to the process of opening discontinuous high-performance fibers after mixing them with thermoplastic resin fibers. The surface of the discontinuous high-performance fibers is free of slurry. It is characterized in that It also includes the sizing process; The sizing process is a single process, located between the carding process and the gathering process, using a spray method; the sizing rate is equal to the set sizing rate, which is no higher than 3%; The clothes are dried at the same time as they are gathered.

2. A process for producing continuous yarn for winding according to claim 1, characterized in that: The concentration of the sizing liquid used for sizing is 3.5-6.5wt% and the viscosity is 15-45mPa·s.

3. The production process of a continuous yarn for winding according to claim 1, characterized in that: The average length of the non-continuous high-performance fiber is 40-200 mm, and the non-continuous high-performance fiber is glass fiber, carbon fiber, basalt fiber or boron fiber; the average length of the thermoplastic resin fiber is the same as the non-continuous high-performance fiber, and the thermoplastic resin fiber is PA fiber, PET fiber, PP fiber, PEEK fiber or PPS fiber.

4. A process for producing continuous yarn for winding according to claim 1, characterized in that: The mixed opening adopts an opener with a feeding speed of 0.5-2.0m / min and an opening beater speed of 800-1500rpm; the carding adopts a carding machine with a cylinder speed of 100-400rpm, a doffer speed of 50-200rpm and a feeding speed of 0.3-1.5m / min; the drawing adopts a drawing frame with a drafting ratio of 1.5-3.0 and a drawing speed of 50-150m / min; when twisting, the twist is set to 20-40T / m and the winding tension is 5-15cN; the fineness of the yarn obtained by gathering is 2383-4873tex, and the fineness of the yarn formed by twisting is 426.3-488.3tex.

5. A production process for continuous yarn for winding, comprising a mixing and opening process, a combing process, a gathering process, a drawing process, and a twisting process; Mixed opening refers to the process of opening discontinuous high-performance fibers and thermoplastic resin fibers after mixing them. The surface of the discontinuous high-performance fibers is free of slurry. It is characterized in that It also includes the sizing process; There are two sizing processes. The first sizing process is located between the carding process and the gathering process and adopts the spraying method. The second sizing process is located after the twisting process and adopts the dipping method. The sizing agent used in the two sizing processes is the same. The sizing rate of the first sizing process is 60-75% of the set sizing rate. The total sizing rate of the two sizing processes is equal to the set sizing rate, and the set sizing rate is not higher than 3%; The clothes are dried at the same time as they are gathered.

6. A process for producing continuous yarn for winding according to claim 5, characterized in that: The concentration of the sizing liquid used in the first sizing is 3.5-6.5wt% and the viscosity is 15-45mPa·s; the concentration of the sizing liquid used in the second sizing is 1.0-2.5wt% and the viscosity is 2-10mPa·s; during the second sizing, the immersion temperature is 35-60°C and the immersion time is 5-20s.

7. A process for producing continuous yarn for winding according to claim 5, characterized in that: The method also includes a wrapping process between the twisting process and the second sizing process, in which the continuous fiber is wrapped around the twisted yarn.

8. A process for producing continuous yarn for winding according to claim 7, characterized in that: The continuous fiber is a small-tow continuous fiber with a fineness of 20-150D; during wrapping, the wrapping speed is 50-200m / min, the wrapping angle is 15-35°, the wrapping tension is 5-20cN, and the wrapping twist is 200-800T / m.

9. A continuous yarn for winding, characterized in that: The continuous yarn is produced by the production process of a continuous yarn for winding molding as described in any one of claims 7 to 8.

10. The use of a continuous yarn for winding as claimed in claim 9, characterized in that: The continuous yarn for winding molding is impregnated with a resin matrix and then wound onto a core mold. The yarn is then heated and cured, and then cooled and demolded to obtain a unidirectional fiber winding reinforced composite material.

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