Thermoplastic resin-based composite material, method for producing the same, and use thereof

Abstract

This invention relates to the field of thermoplastic composite material preparation technology, and discloses a thermoplastic resin-based composite material, its preparation method, and its application. The preparation method includes: mixing molten resin with a fabric in a flowing state for a first contact impregnation, followed by a second contact impregnation under pressure; calendering the impregnated material to obtain a prepreg; and then molding the prepreg to obtain the composite material; wherein, based on the total weight of the impregnated material, the resin content is 30-40 wt%; and the temperature of the second contact impregnation is 10-25°C higher than that of the first contact impregnation. The composite material prepared by the method of this invention has a uniform resin distribution, low porosity, a resin content dispersion value of <4%, and a porosity of <0.05%, making it particularly suitable for use in high-performance thermoplastic composite material parts in the aerospace industry.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic composite material preparation technology, specifically to a thermoplastic resin-based composite material, its preparation method, and its application. Background Technology

[0002] Thermoplastic composites possess characteristics such as good toughness, high fatigue strength, corrosion resistance, and the ability to be integrally molded, and are widely used in the aerospace field. Thermoplastic composites used in the aerospace industry mainly use continuous carbon fibers as reinforcement and special engineering plastics such as polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and polyetherimide (PEI) as matrix resins.

[0003] Currently, there are very limited methods for preparing fabric prepregs using this type of resin as a matrix. The main methods that have been studied and reported are the powder-spreading method and the slurry method. The powder-spreading method suffers from uneven resin content, while the slurry method suffers from incomplete solvent removal, which can lead to defects in the composite material, and uneven powder dispersion in the slurry.

[0004] Therefore, it is urgent to explore the preparation method of high melting point resin-based fabric prepreg to meet the development needs of high-performance thermoplastic composite parts in the aerospace industry. Summary of the Invention

[0005] This invention provides a thermoplastic resin-based composite material, its preparation method, and its application. The composite material prepared using the preparation method of this invention has uniform resin distribution and low porosity, making it particularly suitable for use in high-performance thermoplastic composite parts for the aerospace industry.

[0006] According to a first aspect of the present invention, the present invention provides a method for preparing a thermoplastic resin-based composite material, the method comprising: mixing molten resin with a fabric in a flowing state for a first contact impregnation, then performing a second contact impregnation under pressure, calendering the impregnated material to obtain a prepreg, and then molding the prepreg to obtain a composite material; wherein, based on the total weight of the impregnated material, the resin content is 30~40wt%; and the temperature of the second contact impregnation is 10-40°C higher than that of the first contact impregnation.

[0007] According to a second aspect of the present invention, the present invention provides a composite material prepared by the preparation method of the present invention, wherein the composite material has a porosity of <0.05% and a resin content dispersion of <4%.

[0008] According to a third aspect of the present invention, the present invention provides an application of the composite material described herein in high-performance thermoplastic composite parts for the aerospace industry.

[0009] The method for preparing thermoplastic resin-based composite materials provided by the present invention involves first contacting the resin to a certain flow state and fully melting and impregnating it with fiber fabric, followed by pressure impregnation, calendering to obtain a prepreg, and finally molding the prepreg to obtain a composite material. The resin is uniformly distributed and has low porosity, making it suitable for use in high-performance thermoplastic composite parts in the aerospace industry. Attached Figure Description

[0010] Figure 1 This is a porosity diagram of the composite material prepared in Example 1; Figure 2 This is a porosity diagram of the composite material prepared in Example 2; Figure 3 This is a porosity diagram of the composite material prepared in Example 3; Figure 4 This is a porosity diagram of the composite material prepared in Example 4; Figure 5 This is a porosity diagram of the composite material prepared in Example 5; Figure 6 This is a porosity diagram of the composite material prepared in Example 6; Figure 7 This is a porosity diagram of the composite material prepared in Comparative Example 1; Figure 8 This is a porosity diagram of the composite material prepared in Comparative Example 4. Detailed Implementation

[0011] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0012] This invention provides a method for preparing a thermoplastic resin-based composite material. The method includes: mixing molten resin with a fabric in a flowing state for a first contact impregnation, followed by a second contact impregnation under pressure, calendering the impregnated material to obtain a prepreg, and then molding the prepreg to obtain a composite material; wherein, based on the total weight of the impregnated material, the resin content is 30~40wt%; and the temperature of the second contact impregnation is 10~25℃ higher than that of the first contact impregnation.

[0013] According to a preferred embodiment of the present invention, the temperature of the second contact impregnation is 15-20°C higher than that of the first contact impregnation, for example, 16°C, 17°C, 18°C, 19°C, etc.

[0014] In this invention, the temperature range of the first contact impregnation is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the temperature of the first contact impregnation is 200~375°C.

[0015] In this invention, there is no pressure requirement for the first contact impregnation; it can be carried out under normal pressure.

[0016] In this invention, there are no special requirements for the linear velocity in the first contact impregnation. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the linear velocity is 0.5~3m / min.

[0017] In this invention, the temperature of the second contact impregnation is 210~400℃.

[0018] In this invention, the second contact impregnation is carried out under pressure. According to a preferred embodiment of the invention, the pressure of the second contact impregnation is 0.5~5MPa, for example, 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa, etc.

[0019] In this invention, the linear velocity of the second contact impregnation is the same as that of the first contact impregnation, which is 0.5~3m / min.

[0020] In this invention, there are no special requirements for the type of fabric. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the fabric is selected from fiber fabrics, preferably one or more of carbon fiber, glass fiber, aramid fiber, and basalt fiber.

[0021] In this invention, there are no special requirements for the fabric form of the fabric. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the fabric form of the fabric is selected from one or more of unidirectional fabric, plain weave fabric, twill weave fabric, satin weave fabric, and warp-knitted fabric.

[0022] In this invention, the areal density of the fabric can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the areal density of the fabric is 50~600 g / m². 2 .

[0023] In this invention, the range of resins that can be selected is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the resin is selected from thermoplastic resins, preferably one or more of PPS, PEEK, PEKK, PAEK, and PEI.

[0024] According to a preferred embodiment of the present invention, the preparation method includes: feeding molten resin into a channel to fill the channel in a flowing state; feeding a fabric into the channel, subjecting it to contact impregnation and second contact impregnation under pressure from rollers, and then feeding the fully impregnated material into calendering rollers to obtain a prepreg; and then laying, molding, cooling, and opening the mold to obtain a composite material.

[0025] In this invention, the roller pressure applied to the rollers can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the roller pressure applied to the rollers is 0.5~5MPa.

[0026] In this invention, the rolling temperature can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the rolling temperature is 100~250°C.

[0027] In this invention, the operations of prepreg layering, molding, cooling, and mold opening are well known to those skilled in the art and will not be described in detail here. This invention does not impose any special requirements on the above-mentioned operational conditions.

[0028] The preparation process of the molten resin described in this invention is well known to those skilled in the art, and this invention does not impose any special requirements on it. For example, the preparation steps of the molten resin may include: feeding the dried thermoplastic resin into a screw extruder through a vacuum filler, heating, shearing, melting, and extruding. No special requirements are placed on the specific conditions of the above operations.

[0029] The composite material prepared by the method described in this invention has low porosity, uniform resin content, porosity <0.05%, and resin content dispersion value <4%, making it particularly suitable for use in high-performance thermoplastic composite parts in the aerospace industry.

[0030] The present invention will be described in detail below through embodiments.

[0031] In the following embodiments, The resin content was determined according to the method in GB / T32788.5; The method for calculating the discrete values ​​of resin content is as follows: (Standard deviation of resin content / average resin content) × 100%; Porosity was measured according to GB / T3365; The fabric is SCF35 carbon fiber satin fabric from Sinopec Shanghai Petrochemical Co., Ltd. PPS resin (melting point 285℃), PAEK resin (melting point 360℃), and PEEK resin (melting point 385℃) are all commercially available.

[0032] Example 1 Molten PPS resin was sheared and melted before being extruded into the channel, maintaining the resin filling the channel and flowing at a linear velocity of 1 m / min; a fabric (area density of 280 g / m²) was then added. 2 The fabric is fed into the tunnel, where it undergoes first contact impregnation (300℃) with the resin. It then passes through the second contact impregnation (320℃) for roller pressing impregnation at a pressure of 0.5MPa, ensuring thorough impregnation. The fully impregnated material is then fed into calendering rollers at 120℃ to obtain a prepreg. The prepreg is then layered, molded, cooled, and the mold is opened. Molding conditions are: temperature 320℃, pressure 3MPa, molding time 60min. The resulting composite material has the porosity diagram shown below. Figure 1 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0033] Example 2 Molten PPS resin was sheared and melted before being extruded into the channel, maintaining the resin filling the channel and flowing at a linear velocity of 2.5 m / min; a fabric (area density of 320 g / m²) was then added. 2 The fabric is fed into the tunnel, where it undergoes first contact impregnation (300℃) with the resin. It then passes through the second contact impregnation (320℃) for roller pressing impregnation at a pressure of 2MPa, ensuring thorough impregnation. The fully impregnated material is then fed into calendering rollers at a calendering temperature of 120℃ to obtain a prepreg. The prepreg is then layered, molded, cooled, and the mold is opened. Molding conditions are: temperature 320℃, pressure 5MPa, and molding time 60 minutes. The resulting composite material has the porosity diagram shown below. Figure 2 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0034] Example 3 Molten PPS resin was sheared and melted before being extruded into the channel, maintaining the resin filling the channel and flowing at a linear velocity of 2 m / min; a fabric (area density of 300 g / m²) was then added. 2The fabric is fed into the tunnel, where it undergoes first contact impregnation (300℃) with resin, followed by second contact impregnation (320℃) with roller pressing at a pressure of 1.25MPa to ensure thorough impregnation. The fully impregnated material is then fed into calendering rollers at a calendering temperature of 120℃ to obtain a prepreg. The prepreg is then layered, molded, cooled, and the mold is opened. Molding conditions are: temperature 320℃, pressure 4MPa, molding time 60min. The resulting composite material has the porosity diagram shown below. Figure 3 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0035] Example 4 Molten PAEK resin was sheared and melted before being extruded into the channel, maintaining the resin filling the channel and flowing at a linear velocity of 2 m / min; a fabric (area density of 280 g / m²) was then added. 2 The fabric is fed into the tunnel, where it undergoes first contact impregnation (360℃) with resin, followed by second contact impregnation (380℃) with roller pressing at a pressure of 1.25 MPa to ensure thorough impregnation. The fully impregnated material is then fed into calendering rollers at a calendering temperature of 180℃ to obtain a prepreg. The prepreg is then layered, molded, cooled, and the mold is opened. Molding conditions are: 360℃, 4 MPa, and 90 minutes. The resulting composite material has the following porosity diagram: [Diagram would be inserted here]. Figure 4 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0036] Example 5 Molten PEEK resin was sheared and melted before being extruded into the channel, maintaining the resin filling the channel and flowing at a linear velocity of 2 m / min; a fabric (area density of 280 g / m²) was then added. 2 The fabric is fed into the tunnel, where it undergoes first contact impregnation (370℃) with the resin. It then passes through the second contact impregnation (390℃) for roller pressing impregnation at a pressure of 1.25 MPa, ensuring thorough impregnation. The fully impregnated material is then fed into calendering rollers at a calendering temperature of 200℃ to obtain a prepreg. The prepreg is then layered, molded, cooled, and the mold is opened. Molding conditions are: temperature 380℃, pressure 6 MPa, and molding time 90 minutes. The resulting composite material has the porosity diagram shown below. Figure 5 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0037] Example 6 Molten PEEK resin was sheared and melted before being extruded into the channel, maintaining the resin filling the channel and flowing at a linear velocity of 2 m / min; a fabric (area density of 300 g / m²) was then added. 2 The fabric is fed into the tunnel, where it undergoes first contact impregnation (370℃) with the resin. It then passes through the second contact impregnation (390℃) for roller pressing impregnation at a pressure of 2MPa, ensuring thorough impregnation. The fully impregnated material is then fed into calendering rollers at a calendering temperature of 200℃ to obtain a prepreg. The prepreg is then layered, molded, cooled, and the mold is opened. Molding conditions are: temperature 380℃, pressure 8MPa, and molding time 90 minutes. The resulting composite material has the porosity diagram shown below. Figure 6 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0038] Comparative Example 1 With a surface density of 200g / m 2 After unwinding, the carbon fiber plain weave fabric is evenly sprayed with PPS resin powder (particle size 100-300 micrometers) using a powder spraying device. The powder is then melted in a 300°C oven, hot-pressed, and cooled to prepare a fabric prepreg. This prepreg is then molded into a composite material. The porosity diagram of the prepared composite material is shown in the figure below. Figure 7 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0039] Comparative Example 2 The method of Example 1 was followed, except that the second contact impregnation temperature was 35°C higher than the first contact impregnation temperature, and the second contact impregnation was carried out under normal pressure, while other conditions remained unchanged. The porosity diagram of the prepared composite material is shown below. Figure 8 As shown in Table 1, the resin content, resin content dispersion, and porosity of the composite material were calculated.

[0040] Table 1

[0041] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method of producing a thermoplastic resin-based composite material, characterized by, The method includes: mixing molten resin with fabric in a flowing state for a first contact impregnation, then performing a second contact impregnation under pressure, calendering the impregnated material to obtain a prepreg, and then molding the prepreg to obtain a composite material. The resin content, based on the total weight of the impregnated material, is 30-40 wt%. The temperature of the second contact impregnation is 10~25°C higher than that of the first contact impregnation.

2. The production method according to claim 1, wherein The temperature of the second contact impregnation is 15-20°C higher than that of the first contact impregnation.

3. The production method according to claim 1 or 2, wherein The conditions for the first contact impregnation include: Temperatures of 200~375℃; and / or The pressure is atmospheric pressure; and / or The linear velocity is 0.5~3m / min.

4. The production method according to any one of claims 1 to 3, wherein The conditions for the second contact impregnation include: Temperatures of 210~400℃; and / or Pressure is 0.5~5MPa; and / or The linear velocity is 0.5~3m / min.

5. The preparation method according to any one of claims 1-4, wherein, The fabric is selected from fiber fabrics, preferably one or more of carbon fiber, glass fiber, aramid fiber, and basalt fiber; and / or The fabric type is selected from one or more of the following: unidirectional fabric, plain weave fabric, twill weave fabric, satin weave fabric, and warp-knitted fabric.

6. The preparation method according to any one of claims 1-5, wherein, The fabric has an areal density of 50 to 600 g / m 2 ; and / or The resin is selected from thermoplastic resins, preferably one or more of PPS, PEEK, PEKK, PAEK, and PEI.

7. The production process according to any one of claims 1 to 6, wherein The method includes: feeding molten resin into a channel, so that the molten resin is in a flowing state and fills the channel; feeding fabric into the channel, subjecting it to first contact impregnation and second contact impregnation under pressure from rollers, and then feeding the fully impregnated material into calendering rollers to calender and form a prepreg; and then laying, molding, cooling, and opening the mold to obtain a composite material.

8. The preparation method according to claim 7, wherein, The pressure applied to the rollers is 0.5~5MPa; and / or The rolling temperature is 100~250℃.

9. The composite material prepared by the method according to any one of claims 1 to 8, characterized in that, The composite material has a porosity of <0.05% and a resin content dispersion of <4%.

10. The application of the composite material described in claim 9 in high-performance thermoplastic composite parts for the aerospace industry.

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