Lcp and aramid hybrid thermoplastic composite material and preparation method thereof

Abstract

The application discloses a kind of LCP and aramid mixed weaving thermoplastic composite material, including the following weight parts of raw materials: LCP fiber 35~70 parts, aramid fiber 15~35 parts, thermoplastic matrix resin 15~50 parts, coupling agent 0.1~2 parts, antioxidant 0.1~1 parts, lubricant 0.1~1 parts;Wherein the mass ratio of LCP fiber and aramid fiber is 7:3~5:5, and the mass ratio of thermoplastic matrix resin and mixed weaving fiber preform is 3:7~5:5;Thermoplastic matrix resin is selected from at least one of modified thermoplastic polyurethane, PEEK, PA66, thermoplastic PI or modified PP.The composite material prepared in the application has high strength, high modulus, low dielectric constant, low thermal expansion coefficient and good electromagnetic shielding performance, and is suitable for electronic product structural parts, circuit board and other fields.

Description

Technical Field

[0001] This invention relates to the field of composite materials, specifically to a thermoplastic composite material of LCP and aramid blends and its preparation method. Background Technology

[0002] Liquid crystal polymers (LCPs) are high-performance engineering plastics with high mechanical strength, extremely low linear coefficient of thermal expansion, excellent chemical resistance, and low dielectric constant and loss factor at high frequencies. They are widely used in electronics, aerospace, and automotive industries. Aramid fibers, on the other hand, are attracting attention in the field of composite materials due to their high strength, high modulus, high temperature resistance, and corrosion resistance. Combining these two high-performance materials to prepare blended thermoplastic composites can fully leverage their respective advantages and meet the demands of modern electronic products for lightweight, high strength, high heat resistance, and electromagnetic shielding capabilities.

[0003] Currently, there are various technical solutions for fiber-reinforced thermoplastic composites. CN106916447A discloses a method for preparing aramid fiber-modified long glass fiber reinforced thermoplastic. This method is based on the long fiber reinforced thermoplastic pellet process (LFT-G), utilizing the high strength, high toughness, and high flexibility of aramid fibers to uniformly disperse and interweave the aramid fibers in the three-dimensional rigid skeleton of the long glass fiber reinforced thermoplastic, thereby improving the toughness and impact resistance of the composite material. CN107298813A proposes a prepreg tape based on high-temperature resistant thermoplastic composite resin and its preparation method. This method uses aramid-carbon fiber retwisted fiber as the reinforcing material of the prepreg tape. The two fibers can complement each other, further improving the high-temperature resistance of the fibers. CN107245229B discloses a continuous aramid-basalt fiber retwisted fiber reinforced thermoplastic resin prepreg tape and its preparation method. By combining aramid and basalt fiber, the technical problem of poor flame retardancy of single aramid is overcome.

[0004] In the field of high-performance composite materials, CN114437499A introduces a high thermal conductivity and high strength aramid carbon fiber composite material. This material comprises a matrix resin, modified carbon fibers, modified aramid fibers, modified boron nitride, and a silane coupling agent, exhibiting good thermal conductivity while maintaining high mechanical properties. Furthermore, CN104419202A discloses a wear-resistant reinforced modified PA66 material made of polytetrafluoroethylene (PTFE) and aramid fibers, and its preparation method. This material uses PA66 resin as the matrix resin and PTFE resin and chopped aramid fibers as filler materials. Its tensile strength, flexural strength, flexural modulus, impact strength, and thermal stability all significantly exceed those of traditional glass fiber reinforced modified PA66.

[0005] However, several problems remain to be solved in the existing technology. First, while liquid crystal polyarylate (LCP) materials have many advantages, their inherent brittleness, high notch sensitivity, and relatively insufficient impact resistance limit their application in precision structural components that need to withstand dynamic loads or impact environments. Traditional methods of reinforcing LCP with glass or carbon fibers can improve its stiffness and strength, but offer limited improvement in toughness and may adversely affect dielectric properties. Second, early attempts to combine LCP with aramid fibers through blending, spinning, and composite molding have encountered problems due to poor compatibility, leading to phase separation and extremely unstable material properties. Furthermore, poor bonding between individual fibers and the matrix, as well as low processing adaptability, also restrict further improvements in composite material performance. Especially in high-frequency electronic applications, existing composite materials struggle to simultaneously meet the requirements of high mechanical strength, good toughness, low dielectric constant, and excellent processing performance.

[0006] Therefore, there is an urgent need to develop a new type of LCP and aramid blended thermoplastic composite material. By optimizing the material ratio, improving the fiber surface treatment process, innovating the blended structure design, and refining the hot-pressing composite molding process, the above-mentioned technical problems can be solved and the material performance can be comprehensively improved. Summary of the Invention

[0007] To address the inherent brittleness, high notch sensitivity, and insufficient impact resistance of liquid crystal polyarylate (LCP) materials in existing technologies, and to achieve excellent high-frequency dielectric properties, precise matching of mechanical and dielectric properties, low thermal shrinkage, and good impact resistance, this invention provides an LCP-aramid blended thermoplastic composite material and its preparation method.

[0008] The objective of this invention is achieved through the following technical solution: a thermoplastic composite material made of LCP and aramid blends, comprising the following raw materials in parts by weight: The mixture comprises 35-70 parts LCP fiber, 15-35 parts aramid fiber, 15-50 parts thermoplastic matrix resin, 0.1-2 parts coupling agent, 0.1-1 parts antioxidant, and 0.1-1 parts lubricant; wherein the mass ratio of LCP fiber to aramid fiber is 7:3-5:5, and the mass ratio of thermoplastic matrix resin to blended fiber preform is 3:7-5:5.

[0009] Preferably, the LCP fiber is a melt-spun high heat-resistant liquid crystal polyarylate fiber with a melting point of 280~320℃, a glass transition temperature Tg≥150℃, a fineness of 50~200D, a breaking strength ≥8.0cN / dtex, and a dielectric constant ε≤2.5 at a frequency of 1GHz; preferably, the LCP fiber is an aromatic LCP containing a benzene ring rigid structure, selected from polyethylene terephthalate-CO-hydroxybenzoate.

[0010] Preferably, the aramid fiber is para-aramid fiber with a fineness of 50~200D, a breaking strength ≥20cN / dtex, a breaking elongation of 3~5%, and a water absorption rate ≤0.02%.

[0011] Preferably, the thermoplastic matrix resin is selected from at least one of modified thermoplastic polyurethane, polyetheretherketone (PEEK), polyamide 66 (PA66), thermoplastic polyimide (PI), or modified polypropylene (PP). The modified thermoplastic polyurethane is composed of TPU particles, a compatibility modifier, and an anti-aging additive in a mass ratio of 10~50:3~8:0.4~0.8. The modified thermoplastic polyurethane is obtained by heating the TPU particles, compatibility modifier, and anti-aging additive to ≤50℃ and mixing and stirring for 5~8 minutes. The compatibility modifier is a polyolefin elastomer grafted with glycidyl methacrylate, and the anti-aging additive is a compound composed of antioxidant 1010 and ultraviolet light absorber UV-328 in a mass ratio of 1:1-1.6.

[0012] This invention improves the compatibility of modified thermoplastic polyurethane with LCP fiber and aramid fiber, while enhancing the aging resistance of the composite material and avoiding problems such as matrix cracking and fiber shedding during long-term use. This complements the high wear resistance and oxidation resistance of the TPU composite film, further enhancing the overall performance of the composite material.

[0013] The PEEK has a melting point of 343℃, making it suitable for high-temperature automotive electronics applications. The PA66 has a melting point of 265°C and is suitable for general consumer electronics applications. The thermoplastic PI has a melting point of 310℃, making it suitable for high-temperature automotive electronics applications. The modified PP is a high-flow grade, suitable for conventional consumer electronics scenarios; The modified thermoplastic polyurethane, by introducing specific functional groups (hydroxyl and carboxyl groups), can form stable chemical bonds with the surface active groups of LCP fibers pretreated with coupling agents and doubly modified aramid fibers. Simultaneously, its melt flowability is optimized, allowing it to rapidly and uniformly penetrate into the micro-gaps of the LCP / aramid blended fiber preform during hot-pressing, filling the gaps between fibers, improving the density of the composite material, and leveraging the wear resistance and tear resistance advantages of the TPU composite film. This allows the composite material to balance rigidity and toughness, addressing the technical shortcomings of existing thermoplastic matrix resins, which either lack sufficient rigidity or have poor toughness. Unlike ordinary modified thermoplastic polyurethane, it is specifically modified for the characteristics of the LCP and aramid blended structure, resulting in stronger adaptability. Furthermore, combined with the core technology of the TPU composite film, it achieves a synergistic reinforcement effect between the matrix resin and the blended fiber, which cannot be obtained through conventional selection or simple replacement by those skilled in the art.

[0014] Preferably, the thermoplastic matrix resin is pre-formed into a powder with a particle size of 50-100 μm; or into a film with a thickness of 20-50 μm.

[0015] Preferably, the coupling agent is KH-550 silane coupling agent, and the LCP fiber and / or aramid fiber are pretreated with the coupling agent. The pretreatment includes: immersing the fiber in an ethanol-water solution of KH-550 silane coupling agent with a mass fraction of 1-2% for 20-40 minutes at room temperature, followed by drying at 80-120°C for 1-2 hours, wherein the volume ratio of ethanol to water in the ethanol-water solution is 9:1 and the pH value is 4-5.

[0016] Preferably, the antioxidant is a compound of 1010 and 168 in a mass ratio of 1:2; and the lubricant is zinc stearate.

[0017] Preferably, the composite material further includes 1 to 10 parts of electromagnetic shielding filler, wherein the electromagnetic shielding filler is selected from at least one of graphene and silver-coated copper powder, and the particle size is 1 to 5 μm.

[0018] In this invention, if the thermoplastic matrix resin is modified thermoplastic polyurethane, the electromagnetic shielding filler can form good dispersibility with the system. The molecular structure of the modified thermoplastic polyurethane can play a role in dispersing and stabilizing graphene and silver-coated copper powder, avoiding filler agglomeration, ensuring uniform electromagnetic shielding performance of the composite material, and at the same time not affecting the toughness and processing performance of the composite material, thus achieving a synergistic improvement of "electromagnetic shielding-mechanical properties".

[0019] Preferably, the LCP fiber and aramid fiber form a differentiated blended structure, the blended structure is a plain weave structure, the warp and weft density is 20 to 40 threads / cm, and the preform thickness is 0.05 to 0.15 mm; wherein, the warp and / or weft directions adopt differentiated blending ratios, the mass ratio of warp LCP fiber to aramid fiber is 4:1-2, and the mass ratio of weft LCP fiber to aramid fiber is 7:3 to 5:5.

[0020] Preferably, the aramid fiber undergoes a dual modification pretreatment: A1. Plasma surface modification: Aramid fibers are placed in a plasma treatment device, argon gas is introduced, the power is 80~120W, and the treatment time is 10~15min. Micro-nano-level uneven structure is formed on the fiber surface and hydroxyl and carboxyl active groups are introduced. A2. Alkaline etching: The surface-modified aramid fiber is immersed in a sodium hydroxide solution with a mass fraction of 18~22% and soaked at 80℃ for 1~3 hours. After cleaning until neutral, it is dried.

[0021] This invention also provides a method for preparing a thermoplastic composite material blended with LCP and aramid fibers, which includes the following steps: S1. Raw material preparation: Weigh out 35-70 parts of LCP fiber, 15-35 parts of aramid fiber, 15-50 parts of thermoplastic matrix resin, 0.1-2 parts of coupling agent, 0.1-1 parts of antioxidant, and 0.1-1 parts of lubricant by weight. S2. Refined pretreatment of raw materials: S2-1, LCP fiber pretreatment: The LCP fibers are ultrasonically cleaned in anhydrous ethanol for 20-30 minutes at a power of 300W and a frequency of 40kHz, and then vacuum dried at 80-100℃ for 1-2 hours at a vacuum degree of -0.08 to -0.1MPa to obtain degreased and dried LCP fibers; The degreased and dried LCP fibers are immersed in a 1-2% (w / w) KH-550 silane coupling agent ethanol aqueous solution for 30 minutes at room temperature, and then dried at 120℃ for 2 hours to obtain coupling agent modified LCP fiber bundles; S2-2, Dual Modification of Aramid Fibers: The aramid fiber filaments are mixed with pulp and placed in a plasma treatment device. Argon gas is introduced at a power of 80-120W for 10-15 minutes to obtain plasma-activated aramid fibers. The plasma-activated aramid fibers are then placed in a 1-2% (w / w) KH-550 silane coupling agent ethanol solution and soaked at room temperature for 30-40 minutes. After removal, they are dried at 80-100℃ for 1-2 hours to obtain coupling agent-grafted aramid fibers. The coupling agent-grafted aramid fibers are then placed in an 18-22% (w / w) sodium hydroxide solution and soaked at 80℃ for 1-3 hours. After washing until neutral, they are dried to obtain dual-modified aramid fiber bundles. S2-3. Pretreatment of thermoplastic matrix and additives: The thermoplastic matrix resin powder or film is placed in a vacuum drying oven for drying. PA66 / PP is dried at 80℃ for 2 hours, and PEEK / PI is dried at 120℃ for 1 hour to obtain a dried thermoplastic matrix resin. If electromagnetic shielding filler and / or antioxidant are added, the dried thermoplastic matrix resin and additives are mixed using a high-speed mixer at a speed of 1000~1500 r / min for 10~15 min and a temperature ≤50℃ to obtain a premixed modified thermoplastic matrix resin. Preparation of S3, LCP / aramid blended fiber preform The coupling agent-modified LCP fiber bundles and the doubly modified aramid fiber bundles obtained in step S2 are warped separately at a warping speed of 200-300 m / min and a tension control of 5-10 cN / tex to obtain LCP fiber warp beams and aramid fiber warp beams. The LCP fiber warp beams and aramid fiber warp beams are then alternately arranged in a preset ratio and plain-weave mixed weaving is performed on a rapier loom with an opening height of 10-20 mm, a weft insertion force of 100-200 N, and a weft insertion speed of... The fabric has a weft speed of 150~250m / min, a warp ratio of 4:1 for the coupling agent-modified LCP fiber bundle to the double-modified aramid fiber bundle, a weft ratio of 7:3~5:5 for the coupling agent-modified LCP fiber bundle to the double-modified aramid fiber bundle, a warp and weft density of 20 threads / cm~40 threads / cm, a preform thickness of 0.05~0.15mm, and is dried at 100℃ for 2h after weaving to obtain an LCP / aramid blended fiber preform. S4, Hot-pressed composite molding S4-1. Preparation before lamination: Select a stainless steel mold with a polishing precision ≤ Ra 0.2μm, spray with a polytetrafluoroethylene-based high-temperature release agent, and preheat to 50~80℃ below the melting point of the base resin. S4-2, Preform Laying: The dried thermoplastic matrix resin or the premixed modified thermoplastic matrix resin obtained in step S2 and the LCP / aramid blended fiber preform obtained in step S3 are laid into the mold in a symmetrical laying pattern of "matrix resin-LCP / aramid blended fiber preform-matrix resin". The mass ratio of the dried thermoplastic matrix resin or the premixed modified thermoplastic matrix resin to the LCP / aramid blended fiber preform is 3:7~5:5 to obtain the preform to be composited. S4-3, Hot Pressing Composite: Place the blank to be composited into a flat hot press and operate according to the four-stage process curve: The first stage of heating and melting: the temperature is increased to 20-40°C above the melting temperature of the matrix resin at a heating rate of 5-10°C / min. During the heating process, a pre-pressure of 0.5-1.0 MPa is applied to ensure that the composite blanks are tightly bonded together. The second stage involves heat preservation and pressure holding: maintaining the temperature and pressure at the final temperature for 5-20 minutes, while simultaneously increasing the pressure to 3-8 MPa, so that the molten dry thermoplastic matrix resin or the premixed modified thermoplastic matrix resin can fully penetrate into the gaps of the LCP / aramid blended fiber preform and form chemical bonds with the coupling agent on the surface of the coupling agent modified LCP fiber bundle and the double-modified aramid fiber bundle. The third stage of cooling and crystallization: The temperature is slowly reduced at a rate of 2~5℃ / min while maintaining the main pressure, until the temperature drops to 50℃ below the glass transition temperature of the matrix resin, so that the dried thermoplastic matrix resin or the premixed modified thermoplastic matrix resin can be cured and crystallized. Fourth stage: Depressurization and part removal: Depressurize slowly at a depressurization rate of 0.5 MPa / min and remove the composite LCP / aramid blended thermoplastic composite preform; S5. Post-molding processing S5-1, Stress-relief annealing: The LCP / aramid blended thermoplastic composite preform obtained in step S4 is placed in a forced-air drying oven or a vacuum drying oven, heated at a rate of 3~5℃ / min to 30~50℃ above the Tg of the matrix resin, held at the temperature for 2~4h, and then slowly cooled to room temperature at a rate of 1~2℃ / min to obtain a stress-relief composite material sheet. S5-2, Precision Cutting: The stress-relieved composite material sheet is fed into a CNC cutting machine or laser cutting equipment and precisely cut according to the size of the electronic product component. The cutting accuracy is controlled within ±0.01mm, the laser power is 50~100W, and the speed is 10~50mm / s to obtain a precision-cut composite material part. S5-3. Surface Treatment: Place the precision-cut composite material parts into a plasma treatment instrument and use plasma polishing to achieve a surface roughness Ra ≤ 0.05 μm; treat with an argon / oxygen mixed gas for 5-10 minutes at a power of 100W to increase surface energy; spray a transparent antistatic coating with an antistatic agent concentration of 5-8% and a coating thickness of 5-10 μm to achieve a surface resistivity of 10 Ω. 6 ~10 9 Ω, to obtain the finished LCP / aramid blended thermoplastic composite material.

[0022] The beneficial effects of this invention are as follows: 1. This invention solves the inherent problems of high brittleness and insufficient impact resistance of traditional LCP materials by using a hybrid structure design of LCP fibers and aramid fibers, combined with dual surface modification technology, while maintaining the high strength, heat resistance, dimensional stability, and excellent dielectric properties of LCP. Testing shows that the composite material prepared by this invention maintains a dielectric constant below 2.5 and a dielectric loss ≤0.002 in the high-frequency range of 10~100GHz, far superior to traditional glass fiber reinforced LCP materials (dielectric loss ≥0.005). Furthermore, after being placed in a humid environment of 85℃ and 85%RH for 1000 hours, the dielectric properties decay by ≤5%, meeting the application requirements of high-frequency precision electronic components.

[0023] 2. This invention adopts a warp-weft differentiated knitting process, which achieves precise matching of mechanical and dielectric properties. Through a solvent-free melt composite integrated process, there is no solvent or wastewater discharge throughout the process, making it green and environmentally friendly. The molding yield is increased to over 98%, which is more than 15% higher than the traditional process.

[0024] 3. This invention, through refined post-processing, controls the heat shrinkage rate to within 0.2% and the warpage to ≤0.1mm / 100mm, achieving a precision cutting accuracy of ±0.01mm. This meets the high dimensional stability and precision machining requirements of electronic products and can be applied to high-frequency precision electronic components such as 5G millimeter-wave antennas, high-speed connectors, and low-loss PCB substrates for AI servers. Detailed Implementation

[0025] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0026] Example 1 Step 1: Raw material preparation Prepare the following raw materials in parts by weight: 50 parts LCP fiber, 30 parts aramid fiber, 20 parts thermoplastic matrix resin, 0.5 parts coupling agent, 0.5 parts antioxidant, 0.5 parts lubricant, and 5 parts electromagnetic shielding filler. The mass ratio of LCP fiber to aramid fiber is 5:3, and the mass ratio of thermoplastic matrix resin to the blended fiber preform is 2:8.

[0027] Melt-spun high-heat-resistant liquid crystal polyarylate fiber was selected as the LCP fiber. This fiber has a melting point of 300℃, a glass transition temperature (Tg) of 160℃, a fineness of 100D, a tensile strength of 9.0 cN / dtex, and a dielectric constant (ε) of 2.3 at 1 GHz. The LCP fiber is an aromatic LCP with a rigid benzene ring structure, selected from polyethylene terephthalate-CO-hydroxybenzoate.

[0028] Para-aramid fiber with a fineness of 100D, a breaking strength of 22cN / dtex, a breaking elongation of 4%, and a water absorption rate of 0.01% is selected.

[0029] The coupling agent is KH-550 silane coupling agent. The antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:2. The lubricant is zinc stearate. The electromagnetic shielding filler is a mixture of graphene and silver-coated copper powder in a mass ratio of 1:1, with a particle size of 3μm.

[0030] The thermoplastic matrix resin is a modified thermoplastic polyurethane, which is composed of TPU particles, a compatibility modifier, and an anti-aging additive in a mass ratio of 10~50:3~8:0.4~0.8. The modified thermoplastic polyurethane is obtained by heating the TPU particles, compatibility modifier, and anti-aging additive to ≤50℃ and mixing and stirring for 5~8 minutes. The compatibility modifier is a polyolefin elastomer grafted with glycidyl methacrylate, and the anti-aging additive is a compound composed of antioxidant 1010 and ultraviolet light absorber UV-328 in a mass ratio of 1:1-1.6.

[0031] Step 2: Refined Pretreatment of Raw Materials 1. LCP fiber pretreatment: LCP fibers were ultrasonically cleaned in anhydrous ethanol for 25 minutes (300W, 40kHz) to remove oil from the spinning process. They were then placed in a vacuum drying oven at 90℃ for 0.5 hours (vacuum degree -0.09MPa) to remove internal moisture. The dried LCP fibers were then immersed in a 1.5% (w / w) KH-550 silane coupling agent ethanol-water solution (ethanol:water = 9:1, pH 4.5) at room temperature for 30 minutes. Afterward, they were removed and dried in a 120℃ forced-air drying oven for 2 hours to allow the coupling agent to form a chemically bonded layer on the fiber surface.

[0032] 2. Dual modification pretreatment of aramid fibers: (1) Plasma surface modification: Aramid fibers are placed in a plasma treatment device, argon gas is introduced, power is 100W, and treatment time is 12min. Micro-nano-level uneven structure is formed on the fiber surface and hydroxyl and carboxyl active groups are introduced.

[0033] (2) Alkaline etching: The surface-modified aramid fiber is placed in a 20% sodium hydroxide solution and soaked at 80°C for 2.5 hours. After cleaning until neutral, it is dried at 100°C for 3 hours.

[0034] (3) Coupling agent treatment: The treated aramid fibers were immersed in an aqueous solution of KH-550 silane coupling agent with a mass fraction of 1.5% (ethanol:water = 9:1, pH value 4.5) for 35 minutes at room temperature, and then removed and placed in a 100℃ forced-air drying oven for 2 hours.

[0035] 3. Pretreatment of thermoplastic matrix and additives: The modified thermoplastic polyurethane was placed in a vacuum drying oven and dried at 120℃ for 6 hours to remove moisture from the resin. Antioxidants, lubricants, and electromagnetic shielding fillers were then mixed with the modified thermoplastic polyurethane using a high-speed mixer at a speed of 1200 r / min for 12 minutes, with the mixing temperature controlled below 40℃.

[0036] Step 3: Preparation of LCP / aramid blended fiber preform 1. Determination of mixed weaving process parameters: The LCP fiber to aramid fiber mass ratio is 5:3, the fabric warp and weft density is 30 threads / cm, and the preform thickness is 0.1mm.

[0037] 2. Yarn warping: The pretreated LCP fiber bundles and aramid fiber bundles are warped separately using a high-speed warping machine at a speed of 250 m / min and a tension controlled at 7 cN / tex to ensure uniform tension in each yarn. After warping, the LCP yarns and aramid fibers are alternately arranged on the warp beam in a preset ratio.

[0038] 3. Mixed weaving on rapier looms: The loom parameters were adjusted: sheath height 15mm, weft insertion force 150N, and weft speed 200m / min. An alternating warp / weft blending method was adopted, with a warp LCP fiber to aramid fiber mass ratio of 4:1 and a weft LCP fiber to aramid fiber mass ratio of 5:3. Weaving was carried out under constant temperature (25℃) and constant humidity (50% RH) conditions. After weaving, the blended fiber fabric was cut, and irregular edges were removed to obtain an LCP / aramid blended fiber preform. The blended structure is a plain weave, with a warp and weft density of 30 threads / cm and a preform thickness of 0.1mm.

[0039] Step 4: Preparation of LCP / aramid blended thermoplastic composite material 1. Preparations before getting back together: A stainless steel mold with a polishing precision of Ra 0.2μm was selected. After cleaning the inner wall of the mold, a high-temperature release agent was sprayed on it, and then the mold was preheated to 280℃. The preheated mold was filled with a symmetrical layering method of "matrix resin-LCP / aramid blended preform-matrix resin". Modified thermoplastic polyurethane was evenly spread on both sides of the blended preform using a powder spreader. The powder thickness was uniform, and the deviation was controlled within ±0.03mm.

[0040] 2. Hot-pressing composite: Place the mold with the completed layup into a flatbed hot press, close the mold, and operate according to the following process curve: (1) Heating and melting: The hot press heats up at a rate of 8℃ / min, slowly heating up to 370℃. During the heating process, a pre-pressure of 0.8MPa is applied to ensure that the layers are tightly bonded and to expel air from the gaps.

[0041] (2) Heat preservation and pressure preservation: After heating to 370℃, heat preservation and pressure preservation for 15 minutes, while increasing the pressure to the main pressure of 5MPa. Under high pressure, the molten modified thermoplastic polyurethane fully penetrates into the gaps of LCP / aramid blended fibers and forms chemical bonds with the coupling agent on the fiber surface.

[0042] (3) Cooling and crystallization: After the heat preservation and pressure preservation are completed, the temperature is slowly reduced at a rate of 3℃ / min. During the cooling process, the main pressure is kept constant at 5MPa until the temperature drops to 200℃.

[0043] (4) Depressurization and part removal: After the temperature drops to 200℃, depressurize slowly at a rate of 0.5MPa / min, then open the mold and remove the composite LCP / aramid blended thermoplastic composite blank.

[0044] Step 5: Post-molding processing 1. Stress-relief annealing: The composite material preform was placed in a vacuum drying oven and heated to 260°C at a heating rate of 4°C / min, and held at that temperature for 3 hours. During the holding process, the temperature was kept uniform and there was no local overheating. The preform was then slowly cooled to room temperature at a rate of 1.5°C / min and cooled in the furnace.

[0045] 2. Precision cutting: The cooled composite board is fed into a CNC cutting machine for precise cutting as needed, with the cutting accuracy controlled within ±0.01mm. Edge trimming removes burrs and excess material.

[0046] 3. Surface treatment: Plasma polishing is used to treat the surface of the product, removing surface impurities and oxide layers, achieving a surface roughness Ra of 0.03 μm. Plasma modification: The cut composite material is placed in a plasma treatment instrument and treated with an argon / oxygen mixed gas (volume ratio 9:1) for 8 minutes at a power of 100W to increase surface energy and ensure the bonding strength for subsequent processing.

[0047] Example 2 Step 1: Raw material preparation Prepare the following raw materials in parts by weight: 50 parts LCP fiber, 30 parts aramid fiber, 20 parts thermoplastic matrix resin, 0.5 parts coupling agent, 0.5 parts antioxidant, 0.5 parts lubricant, and 5 parts electromagnetic shielding filler. The mass ratio of LCP fiber to aramid fiber is 5:3, and the mass ratio of thermoplastic matrix resin to the blended fiber preform is 2:8.

[0048] Melt-spun high-heat-resistant liquid crystal polyarylate fiber was selected as the LCP fiber. This fiber has a melting point of 300℃, a glass transition temperature (Tg) of 160℃, a fineness of 100D, a tensile strength of 9.0 cN / dtex, and a dielectric constant (ε) of 2.3 at 1 GHz. The LCP fiber is an aromatic LCP with a rigid benzene ring structure, selected from polyethylene terephthalate-CO-hydroxybenzoate.

[0049] Para-aramid fiber with a fineness of 100D, a breaking strength of 22cN / dtex, a breaking elongation of 4%, and a water absorption rate of 0.01% is selected.

[0050] The thermoplastic matrix resin used is polyetheretherketone (PEEK), with a melting point of 343℃, suitable for high-temperature automotive electronics applications. PEEK is pre-formed into powder with a particle size of 80μm.

[0051] The coupling agent is KH-550 silane coupling agent. The antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:2. The lubricant is zinc stearate. The electromagnetic shielding filler is a mixture of graphene and silver-coated copper powder in a mass ratio of 1:1, with a particle size of 3μm.

[0052] Step 2: Refined Pretreatment of Raw Materials 1. LCP fiber pretreatment: LCP fibers were ultrasonically cleaned in anhydrous ethanol for 25 minutes (300W, 40kHz) to remove oil from the spinning process. They were then placed in a vacuum drying oven at 90℃ for 0.5 hours (vacuum degree -0.09MPa) to remove internal moisture. The dried LCP fibers were then immersed in a 1.5% (w / w) KH-550 silane coupling agent ethanol-water solution (ethanol:water = 9:1, pH 4.5) at room temperature for 30 minutes. Afterward, they were removed and dried in a 120℃ forced-air drying oven for 2 hours to allow the coupling agent to form a chemically bonded layer on the fiber surface.

[0053] 2. Dual modification pretreatment of aramid fibers: (1) Plasma surface modification: Aramid fibers are placed in a plasma treatment device, argon gas is introduced, power is 100W, and treatment time is 12min. Micro-nano-level uneven structure is formed on the fiber surface and hydroxyl and carboxyl active groups are introduced.

[0054] (2) Alkaline etching: The surface-modified aramid fiber is placed in a 20% sodium hydroxide solution and soaked at 80°C for 2.5 hours. After cleaning until neutral, it is dried at 100°C for 3 hours.

[0055] (3) Coupling agent treatment: The treated aramid fibers were immersed in an aqueous solution of KH-550 silane coupling agent with a mass fraction of 1.5% (ethanol:water = 9:1, pH value 4.5) for 35 min at room temperature, and then removed and placed in a 100℃ forced-air drying oven for 2.5 h.

[0056] 3. Pretreatment of thermoplastic matrix and additives: The PEEK powder was placed in a vacuum drying oven and dried at 120°C for 1 hour to remove moisture from the resin. The antioxidant, lubricant, and electromagnetic shielding filler were then mixed with the PEEK powder using a high-speed mixer at a speed of 1200 rpm for 12 minutes, with the mixing temperature controlled below 40°C.

[0057] Step 3: Preparation of LCP / aramid blended fiber preform 1. Determination of mixed weaving process parameters: The LCP fiber to aramid fiber mass ratio is 5:3, the fabric warp and weft density is 30 threads / cm, and the preform thickness is 0.1mm.

[0058] 2. Yarn warping: The pretreated LCP fiber bundles and aramid fiber bundles are warped separately using a high-speed warping machine at a speed of 250 m / min and a tension controlled at 7 cN / tex to ensure uniform tension in each yarn. After warping, the LCP yarns and aramid fibers are alternately arranged on the warp beam in a preset ratio.

[0059] 3. Mixed weaving on rapier looms: The loom parameters were adjusted: sheath height 15mm, weft insertion force 150N, and weft speed 200m / min. An alternating warp / weft blending method was adopted, with a warp LCP fiber to aramid fiber mass ratio of 4:1 and a weft LCP fiber to aramid fiber mass ratio of 5:3. Weaving was carried out under constant temperature (25℃) and constant humidity (50% RH) conditions. After weaving, the blended fiber fabric was cut, and irregular edges were removed to obtain an LCP / aramid blended fiber preform. The blended structure is a plain weave, with a warp and weft density of 30 threads / cm and a preform thickness of 0.1mm.

[0060] Step 4: Preparation of LCP / aramid blended thermoplastic composite material 1. Preparations before getting back together: A stainless steel mold with a polishing precision of Ra 0.2μm was selected. After cleaning the inner wall of the mold, a high-temperature release agent was sprayed on it, and then the mold was preheated to 280℃. The preheated mold was filled with a symmetrical layering method of "matrix resin-LCP / aramid blended preform-matrix resin". PEEK powder was evenly spread on both sides of the blended preform using a powder spreader. The powder thickness was uniform, and the deviation was controlled within ±0.03mm.

[0061] 2. Hot-pressing composite: Place the mold with the completed layup into a flatbed hot press, close the mold, and operate according to the following process curve: (1) Heating and melting: The hot press heats up at a rate of 8℃ / min, slowly heating up to 370℃. During the heating process, a pre-pressure of 0.8MPa is applied to ensure that the layers are tightly bonded and to expel air from the gaps.

[0062] (2) Heat preservation and pressure preservation: After heating to 370℃, heat preservation and pressure preservation for 15 minutes, while increasing the pressure to the main pressure of 5MPa. Under high pressure, the molten PEEK resin fully penetrates into the gaps of LCP / aramid blended fibers and forms chemical bonds with the coupling agent on the fiber surface.

[0063] (3) Cooling and crystallization: After the heat preservation and pressure preservation are completed, the temperature is slowly reduced at a rate of 3℃ / min. During the cooling process, the main pressure is kept constant at 5MPa until the temperature drops to 200℃.

[0064] (4) Depressurization and part removal: After the temperature drops to 200℃, depressurize slowly at a rate of 0.5MPa / min, then open the mold and remove the composite LCP / aramid blended thermoplastic composite blank.

[0065] Step 5: Post-molding processing 1. Stress-relief annealing: The composite material preform was placed in a vacuum drying oven and heated to 260°C at a heating rate of 4°C / min, and held at that temperature for 3 hours. During the holding process, the temperature was kept uniform and there was no local overheating. The preform was then slowly cooled to room temperature at a rate of 1.5°C / min and cooled in the furnace.

[0066] 2. Precision cutting: The cooled composite board is fed into a CNC cutting machine for precise cutting as needed, with the cutting accuracy controlled within ±0.01mm. Edge trimming removes burrs and excess material.

[0067] 3. Surface treatment: Plasma polishing is used to treat the surface of the product, removing surface impurities and oxide layers, achieving a surface roughness Ra of 0.03 μm. Plasma modification: The cut composite material is placed in a plasma treatment instrument and treated with an argon / oxygen mixed gas (volume ratio 9:1) for 8 minutes at a power of 100W to increase surface energy and ensure the bonding strength for subsequent processing.

[0068] Step 6: Performance Testing 1. Mechanical property testing: According to national standards, the standard samples prepared in Example 2 that conform to the material preparation criteria were laser-cut, and five parallel tests were conducted. The average value of the results was taken. The test results showed that the tensile strength of the composite material was 320 MPa, the flexural strength was 280 MPa, and the impact strength was 65 kJ / m², which meets the structural strength requirements of high-temperature automotive electronic products.

[0069] 2. Dielectric property testing: The sample surface was clean, free of impurities and scratches, and placed in an environment of 25℃ and 50% RH for 24 hours before testing. The test results showed that at a frequency of 1GHz, the dielectric constant ε of the composite material was 2.4 and the dielectric loss tanδ was 0.002, which met the requirements for high-frequency signal transmission.

[0070] 3. Thermal performance testing: Test results show that the composite material has a heat distortion temperature of 280℃ and a coefficient of thermal expansion of 8×10⁻⁶. -6 / K, meeting the thermal stability requirements of high-temperature automotive electronic products.

[0071] 4. Electromagnetic shielding performance test: Test results show that the electromagnetic shielding effectiveness of the composite material is 35-45dB in the 1-10GHz frequency range, which meets the electromagnetic shielding requirements of electronic products.

[0072] The LCP-aramid blended thermoplastic composite material obtained by the above preparation method has excellent mechanical properties, thermal stability, dielectric properties and electromagnetic shielding properties, and is suitable for the application requirements of high-temperature automotive electronic products.

[0073] Example 3 A method for preparing an LCP / aramid blended thermoplastic composite material includes the following steps: S1. Raw material preparation: Weigh out 50 parts of LCP fiber, 30 parts of aramid fiber, 20 parts of thermoplastic matrix resin, 0.5 parts of coupling agent, 0.5 parts of antioxidant, 0.5 parts of lubricant, and 5 parts of electromagnetic shielding filler according to the following mass ratios: LCP fiber to aramid fiber is 5:3, and thermoplastic matrix resin to blended fiber preform is 2:8.

[0074] S2. Refined pretreatment of raw materials: S2-1, LCP fiber pretreatment: The LCP fiber pretreatment steps are the same as in Example 2. The LCP fiber is ultrasonically cleaned in anhydrous ethanol for 25 min (power 300W, frequency 40kHz), and then vacuum dried at 90℃ for 0.5 h with a vacuum degree of -0.09MPa to obtain de-oiled and dried LCP fiber. The de-oiled and dried LCP fiber is immersed in a 1.5% KH-550 silane coupling agent ethanol aqueous solution (ethanol:water = 9:1, pH value 4.5) for 30 min at room temperature, and then dried at 120℃ for 2 h to obtain coupling agent modified LCP fiber bundle.

[0075] S2-2, Double Modification of Aramid Fibers: The steps are the same as those in Example 2. Aramid fiber filaments are mixed with pulp and placed in a plasma treatment device. Argon gas is introduced at a power of 100W for 12 minutes to obtain plasma-activated aramid fibers. The plasma-activated aramid fibers are then placed in a 1.5% KH-550 silane coupling agent ethanol solution and soaked at room temperature for 35 minutes. After removal, they are dried at 100°C for 2.5 hours to obtain coupling agent-grafted aramid fibers. The coupling agent-grafted aramid fibers are then placed in a 20% sodium hydroxide solution and soaked at 80°C for 1 hour. After washing until neutral, they are dried to obtain double-modified aramid fiber bundles.

[0076] S2-3. Pretreatment of thermoplastic matrix and additives: Similar to Example 2, this example uses polyetheretherketone (PEEK) as the thermoplastic matrix resin. PEEK powder is placed in a vacuum drying oven and dried at 120°C for 1 hour to obtain a dried thermoplastic matrix resin. Antioxidant, lubricant and electromagnetic shielding filler are mixed with PEEK powder using a high-speed mixer at a speed of 1200 r / min for 12 min. The mixing temperature is controlled below 40°C to obtain a premixed modified thermoplastic matrix resin.

[0077] Preparation of S3, LCP / aramid blended fiber preform: Similar to Example 2, the coupling agent modified LCP fiber bundles and double-modified aramid fiber bundles obtained in step S2 were warped separately at a warping speed of 250 m / min and a tension control of 7 cN / tex to obtain LCP fiber warp beams and aramid fiber warp beams. After the LCP fiber warp beams and aramid fiber warp beams were alternately arranged according to a preset ratio, they were plain-weave mixed on a rapier loom with an opening height of 15 mm, a weft insertion force of 150 N, and a weft insertion speed of 200 m / min. The mass ratio of the warp coupling agent modified LCP fiber bundles to the double-modified aramid fiber bundles was 4:1, and the mass ratio of the weft coupling agent modified LCP fiber bundles to the double-modified aramid fiber bundles was 5:3. The warp and weft density of the fabric was 30 threads / cm, and the preform thickness was 0.1 mm. After weaving, the fabric was dried in a forced-air dryer at 100°C for 2 hours to obtain an LCP / aramid mixed fiber preform.

[0078] S4. Hot pressing composite molding: S4-1. Preparation before lamination: Same as in Example 2, a stainless steel mold with a polishing precision of Ra 0.2μm is selected, a polytetrafluoroethylene-based high-temperature release agent is sprayed on, and the temperature is preheated to 280℃.

[0079] S4-2, Blank Laying: Similar to Example 2, the premixed modified thermoplastic matrix resin obtained in step S2 and the LCP / aramid blended fiber preform obtained in step S3 are laid into the mold in a symmetrical laying pattern of "matrix resin-LCP / aramid blended fiber preform-matrix resin". The mass ratio of premixed modified thermoplastic matrix resin to LCP / aramid blended fiber preform is 2:8 to obtain the blank to be composite.

[0080] S4-3, Hot Pressing Composite: Same as in Example 2, place the blank to be composited into a flat hot press and operate according to the four-stage process curve: The first stage of heating and melting: the temperature is increased to 370°C at a heating rate of 8°C / min. During the heating process, a pre-pressure of 0.8MPa is applied to ensure that the composite blanks are tightly bonded together. The second stage of heat preservation and pressure holding: heat preservation and pressure holding at the final temperature for 15 minutes, while increasing the pressure to 5MPa, so that the molten premixed modified thermoplastic matrix resin can fully penetrate into the gaps of LCP / aramid blended fiber preform and form chemical bonds with the coupling agent on the surface of the coupling agent modified LCP fiber bundle and the double modified aramid fiber bundle. The third stage is cooling and crystallization: the temperature is slowly reduced at a rate of 3℃ / min while maintaining the main pressure, until the temperature drops to 200℃, so that the premixed modified thermoplastic matrix resin can be cured and crystallized. Fourth stage: Depressurization and part removal: Depressurize slowly at a depressurization rate of 0.5 MPa / min and remove the composite LCP / aramid blended thermoplastic composite blank.

[0081] S5. Post-molding processing: S5-1, Stress-relief annealing: Similar to Example 2, the LCP / aramid blended thermoplastic composite preform obtained in step S4 is placed in a vacuum drying oven, heated to 260°C at a heating rate of 4°C / min, held at that temperature for 3 hours, and then slowly cooled to room temperature at a rate of 1.5°C / min to obtain a stress-relief composite material sheet.

[0082] S5-2, Precision Cutting: Similar to Example 2, the stress-relief composite material sheet is fed into a CNC cutting machine and precisely cut according to the size of the electronic product component. The cutting accuracy is controlled within ±0.01mm to obtain a precision-cut composite material part.

[0083] S5-3, Surface treatment: Same as in Example 2, plasma polishing process is used to treat the surface of the product to make the surface roughness Ra 0.03μm; plasma modification is used, the cut composite material is placed in a plasma treatment instrument and treated with argon / oxygen mixed gas (volume ratio 9:1) for 8 minutes at a power of 100W to increase the surface energy and obtain the finished LCP / aramid blended thermoplastic composite material.

[0084] The LCP / aramid blended thermoplastic composite material obtained by the above preparation method exhibits excellent mechanical properties, thermal stability, dielectric properties, and electromagnetic shielding performance, making it suitable for high-temperature automotive electronic product applications. Testing revealed that the composite material has a tensile strength of 320 MPa, a flexural strength of 280 MPa, an impact strength of 65 kJ / m², a dielectric constant ε of 2.4 at 1 GHz, a dielectric loss tanδ of 0.002, a heat distortion temperature of 280℃, and a coefficient of thermal expansion of 8 × 10⁻⁶. -6 / K, with an electromagnetic shielding effectiveness of 35-45dB in the 1-10GHz frequency range.

[0085] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A thermoplastic composite material blended with LCP and aramid fibers, characterized in that: The ingredients include the following parts by weight: The mixture comprises 35-70 parts LCP fiber, 15-35 parts aramid fiber, 15-50 parts thermoplastic matrix resin, 0.1-2 parts coupling agent, 0.1-1 parts antioxidant, and 0.1-1 parts lubricant; wherein the mass ratio of LCP fiber to aramid fiber is 7:3-5:5, and the mass ratio of thermoplastic matrix resin to blended fiber preform is 3:7-5:

5.

2. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The thermoplastic matrix resin is selected from at least one of modified thermoplastic polyurethane, polyetheretherketone, polyamide 66, thermoplastic polyimide, or modified polypropylene.

3. The LCP and aramid blended thermoplastic composite material according to claim 1, characterized in that: The modified thermoplastic polyurethane is composed of TPU particles, a compatibility modifier, and an anti-aging additive in a mass ratio of 10~50:3~8:0.4~0.

8. The modified thermoplastic polyurethane is obtained by heating the TPU particles, compatibility modifier, and anti-aging additive to ≤50℃ and mixing and stirring for 5~8 minutes. The compatibility modifier is a polyolefin elastomer grafted with glycidyl methacrylate, and the anti-aging additive is a compound composed of antioxidant 1010 and ultraviolet light absorber UV-328 in a mass ratio of 1:1-1.

6.

4. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The LCP fiber is a melt-spun high heat-resistant liquid crystal polyaramid fiber with a melting point of 280~320℃, a glass transition temperature Tg≥150℃, and a fineness of 50~200D; the aramid fiber is a para-aramid fiber with a fineness of 50~200D.

5. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The coupling agent is KH-550 silane coupling agent. The LCP fiber and / or aramid fiber are pretreated with the coupling agent. The pretreatment includes: immersing the fiber in an ethanol-water solution of KH-550 silane coupling agent with a mass fraction of 1-2% for 20-40 minutes at room temperature, and then drying it at 80-120°C for 1-2 hours. The volume ratio of ethanol to water in the ethanol-water solution is 9:1, and the pH value is 4-5.

6. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The antioxidant is a compound of 1010 and 168 in a mass ratio of 1:2; the lubricant is zinc stearate.

7. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The composite material also includes 1 to 10 parts of electromagnetic shielding filler, wherein the electromagnetic shielding filler is selected from at least one of graphene and silver-coated copper powder, and the particle size is 1 to 5 μm.

8. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The LCP fiber and aramid fiber form a differentiated blended structure. The blended structure is a plain weave structure with a warp and weft density of 20 to 40 threads / cm and a preform thickness of 0.05 to 0.15 mm. The warp and / or weft directions are blended in a differentiated ratio. The mass ratio of warp LCP fiber to aramid fiber is 4:1-2, and the mass ratio of weft LCP fiber to aramid fiber is 7:3 to 5:

5.

9. The LCP / aramid blended thermoplastic composite material according to claim 1, characterized in that: The aramid fibers undergo dual modification pretreatment: A1. Plasma surface modification: Aramid fibers are placed in a plasma treatment device, argon gas is introduced, the power is 80~120W, and the treatment time is 10~15min. Micro-nano-level uneven structure is formed on the fiber surface and hydroxyl and carboxyl active groups are introduced. A2. Alkaline etching: The surface-modified aramid fiber is immersed in a sodium hydroxide solution with a mass fraction of 18~22% and soaked at 80℃ for 1~3 hours. After cleaning until neutral, it is dried.

10. A method for preparing a thermoplastic composite material of LCP and aramid as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. Raw material preparation: Weigh out 35-70 parts of LCP fiber, 15-35 parts of aramid fiber, 15-50 parts of thermoplastic matrix resin, 0.1-2 parts of coupling agent, 0.1-1 parts of antioxidant, and 0.1-1 parts of lubricant by weight. S2. Refined pretreatment of raw materials: S2-1, LCP fiber pretreatment: The LCP fibers are ultrasonically cleaned in anhydrous ethanol for 20-30 minutes at a power of 300W and a frequency of 40kHz, and then vacuum dried at 80-100℃ for 1-2 hours at a vacuum degree of -0.08 to -0.1MPa to obtain degreased and dried LCP fibers; The degreased and dried LCP fibers are immersed in a 1-2% (w / w) KH-550 silane coupling agent ethanol aqueous solution for 30 minutes at room temperature, and then dried at 120℃ for 2 hours to obtain coupling agent modified LCP fiber bundles; S2-2, Dual Modification of Aramid Fibers: The aramid fiber filaments are mixed with pulp and placed in a plasma treatment device. Argon gas is introduced at a power of 80-120W for 10-15 minutes to obtain plasma-activated aramid fibers. The plasma-activated aramid fibers are then placed in a 1-2% (w / w) KH-550 silane coupling agent ethanol solution and soaked at room temperature for 30-40 minutes. After removal, they are dried at 80-100℃ for 1-2 hours to obtain coupling agent-grafted aramid fibers. The coupling agent-grafted aramid fibers are then placed in an 18-22% (w / w) sodium hydroxide solution and soaked at 80℃ for 1-3 hours. After washing until neutral, they are dried to obtain dual-modified aramid fiber bundles. S2-3. Pretreatment of thermoplastic matrix and additives: The thermoplastic matrix resin powder or film is placed in a vacuum drying oven for drying. PA66 / PP is dried at 80℃ for 2 hours, and PEEK / PI is dried at 120℃ for 1 hour to obtain a dried thermoplastic matrix resin. If electromagnetic shielding filler and / or antioxidant are added, the dried thermoplastic matrix resin and additives are mixed using a high-speed mixer at a speed of 1000~1500 r / min for 10~15 min and a temperature ≤50℃ to obtain a premixed modified thermoplastic matrix resin. Preparation of S3, LCP / aramid blended fiber preform The coupling agent-modified LCP fiber bundles and the doubly modified aramid fiber bundles obtained in step S2 are warped separately at a warping speed of 200-300 m / min and a tension control of 5-10 cN / tex to obtain LCP fiber warp beams and aramid fiber warp beams. The LCP fiber warp beams and aramid fiber warp beams are then alternately arranged in a preset ratio and plain-weave mixed weaving is performed on a rapier loom with an opening height of 10-20 mm, a weft insertion force of 100-200 N, and a weft insertion speed of... The fabric has a weft speed of 150~250m / min, a warp ratio of 4:1 for the coupling agent-modified LCP fiber bundle to the double-modified aramid fiber bundle, a weft ratio of 7:3~5:5 for the coupling agent-modified LCP fiber bundle to the double-modified aramid fiber bundle, a warp and weft density of 20 threads / cm~40 threads / cm, a preform thickness of 0.05~0.15mm, and is dried at 100℃ for 2h after weaving to obtain an LCP / aramid blended fiber preform. S4, Hot-pressed composite molding S4-1. Preparation before lamination: Select a stainless steel mold with a polishing precision ≤ Ra 0.2μm, spray with a polytetrafluoroethylene-based high-temperature release agent, and preheat to 50~80℃ below the melting point of the base resin. S4-2, Preform Laying: The dried thermoplastic matrix resin or the premixed modified thermoplastic matrix resin obtained in step S2 and the LCP / aramid blended fiber preform obtained in step S3 are laid into the mold in a symmetrical laying pattern of "matrix resin-LCP / aramid blended fiber preform-matrix resin". The mass ratio of the dried thermoplastic matrix resin or the premixed modified thermoplastic matrix resin to the LCP / aramid blended fiber preform is 3:7~5:5 to obtain the preform to be composited. S4-3, Hot Pressing Composite: Place the blank to be composited into a flat hot press and operate according to the four-stage process curve: The first stage of heating and melting: the temperature is increased to 20-40°C above the melting temperature of the matrix resin at a heating rate of 5-10°C / min. During the heating process, a pre-pressure of 0.5-1.0 MPa is applied to ensure that the composite blanks are tightly bonded together. The second stage involves heat preservation and pressure holding: maintaining the temperature and pressure at the final temperature for 5-20 minutes, while simultaneously increasing the pressure to 3-8 MPa, so that the molten dry thermoplastic matrix resin or the premixed modified thermoplastic matrix resin can fully penetrate into the gaps of the LCP / aramid blended fiber preform and form chemical bonds with the coupling agent on the surface of the coupling agent modified LCP fiber bundle and the double-modified aramid fiber bundle. The third stage of cooling and crystallization: The temperature is slowly reduced at a rate of 2~5℃ / min while maintaining the main pressure, until the temperature drops to 50℃ below the glass transition temperature of the matrix resin, so that the dried thermoplastic matrix resin or the premixed modified thermoplastic matrix resin can be cured and crystallized. Fourth stage: Depressurization and part removal: Depressurize slowly at a depressurization rate of 0.5 MPa / min and remove the composite LCP / aramid blended thermoplastic composite preform; S5. Post-molding processing S5-1, Stress-relief annealing: The LCP / aramid blended thermoplastic composite preform obtained in step S4 is placed in a forced-air drying oven or a vacuum drying oven, heated at a rate of 3~5℃ / min to 30~50℃ above the Tg of the matrix resin, held at the temperature for 2~4h, and then slowly cooled to room temperature at a rate of 1~2℃ / min to obtain a stress-relief composite material sheet. S5-2, Precision Cutting: The stress-relieved composite material sheet is fed into a CNC cutting machine or laser cutting equipment and precisely cut according to the size of the electronic product component. The cutting accuracy is controlled within ±0.01mm, the laser power is 50~100W, and the speed is 10~50mm / s to obtain a precision-cut composite material part. S5-3. Surface treatment: The precision-cut composite material parts are placed in a plasma treatment instrument and plasma polishing is used to make the surface roughness Ra≤0.05μm; Argon / oxygen mixed gas is used for treatment for 5~10 minutes at a power of 100W to increase the surface energy. Apply a transparent antistatic coating with an antistatic agent concentration of 5-8% and a coating thickness of 5-10 μm to achieve a surface resistivity of 10. 6 ~10 9 Ω, to obtain the finished LCP / aramid blended thermoplastic composite material.