Carbon fiber on-line surface treatment and impregnation device and preparation method

Abstract

The present application relates to a kind of carbon fiber online surface treatment and impregnation device and preparation method.The device is made of carbon fiber desizing unit, sizing unit, impregnation unit and winding unit, can be used for preparing wet carbon fiber reinforced polyimide prepreg, and before carbon fiber impregnation, carbon fiber can be desized and resized according to the functional needs.The device can realize the integration of carbon fiber surface treatment and impregnation function in the preparation process of carbon fiber reinforced polyimide prepreg, so as to solve the poor interfacial bonding force of composite caused by the insufficient temperature resistance of commercial carbon fiber sizing agent and the fiber damage problem in the process of carbon fiber treatment.The carbon fiber reinforced polyimide prepreg prepared by the device shows better interlaminar shear performance and comprehensive mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber reinforced prepreg preparation technology, and relates to an online surface treatment and impregnation device and preparation method for carbon fiber. Background Technology

[0002] As spacecraft speeds, flight durations, and distances continue to increase, their surfaces must withstand harsh aerodynamic heating and high-G complex service environments while flying in the dense atmosphere. Important structural components such as wings, tail sections, and transition sections can reach surface temperatures exceeding 350°C. With the increasing surface temperature of spacecraft and the rising demands for structural efficiency, more stringent requirements are placed on the load-bearing capacity, thermal insulation performance, and lightweighting of structural components. Traditional epoxy composites and bismaleimide composites are no longer sufficient to meet these structural requirements, necessitating the development of polyimide composites as the primary load-bearing components.

[0003] However, in carbon fiber-polyimide composites used as primary load-bearing components, the mismatch between the curing temperature of the sizing agent on the carbon fiber surface and the polyimide composite leads to poor interfacial strength, which to some extent affects their load-bearing efficiency. Therefore, since the 1990s, scholars both domestically and internationally have conducted research on the impact of carbon fiber surface treatment on the properties of polyimide composites. Studies have shown that carbon fiber surface treatment can improve the interfacial characteristics of the composite to a certain extent, especially its thermo-oxidative aging stability. However, the carbon fiber surface treatment process can cause some damage to the fibers, thus affecting the overall performance of the final composite. Therefore, to further improve the load-bearing efficiency of polyimide composites, it is urgent to treat the carbon fiber surface to solve the problem of poor interfacial strength caused by the low temperature resistance of the sizing agent. Simultaneously, it is crucial to reduce fiber damage and maximize the load-bearing capacity of the composite. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide an online surface treatment and impregnation device and preparation method for carbon fibers. It adopts a modular design concept and integrates the surface treatment and resin impregnation of carbon fibers through a desizing unit, a sizing unit, an impregnation unit, and a winding unit. This reduces the damage to carbon fibers caused by multiple unwinding and winding during the surface treatment process, improves the interfacial bonding strength of carbon fiber reinforced polyimide composites, and ensures that the composites still maintain good comprehensive mechanical properties, laying the foundation for the application of polyimide composites in main load-bearing components.

[0005] This invention discloses an online surface treatment and impregnation device for carbon fiber, comprising: a control and drive unit, a desizing unit, a sizing unit, an impregnation unit, a winding unit, and a main frame, wherein: the desizing unit, the sizing unit, the impregnation unit, and the winding unit are sequentially installed on the main frame;

[0006] The desizing unit removes the sizing agent from the surface of the carbon fiber using a solvent;

[0007] The sizing unit re-coates a high-temperature sizing agent onto the carbon fiber surface after the sizing agent has been removed;

[0008] The impregnation unit impregnates the sized carbon fibers with polyimide resin.

[0009] The winding unit, including a roller, uniformly arranges the resin-impregnated carbon fibers according to the control signal from the control and drive unit to obtain carbon fiber reinforced polyimide wet prepreg.

[0010] The control and drive unit controls the winding unit, including the carbon fiber yarn tension, prepreg width, heating temperature, and drum speed.

[0011] Furthermore, in the above-mentioned device, the control and drive unit includes a parameter control interface and a servo driver; wherein, the parameter control interface is used to set parameters such as roller speed, roller lateral movement speed, yarn tension, heating temperature and prepreg width, and the servo driver drives the roller to rotate according to the set parameters.

[0012] Furthermore, in the above-mentioned device, the desizing unit includes a yarn frame, a guide roller, and a solvent tank; wherein, the yarn frame is used to install carbon fibers, the guide roller is used to guide the direction of the carbon fibers, and the solvent tank is used to hold the solvent for carbon fiber surface treatment. The components are connected to the main frame in the order of use. During use, the carbon fiber yarn installed on the yarn frame is guided into the solvent tank by the guide roller for carbon fiber surface solvent treatment.

[0013] Furthermore, in the above-mentioned device, the sizing unit includes a guide roller, a sizing agent tank, and a drying unit; wherein, the guide roller is used for traction of carbon fiber yarn, the sizing agent tank is used to hold high-temperature sizing agent, and the drying unit is used to remove the solvent remaining on the surface of the carbon fiber yarn after the high-temperature sizing agent is applied; the guide roller, the sizing agent tank, and the drying unit are connected on the main frame in the order of use; during use, the carbon fiber yarn treated in the solvent tank is tractioned by the guide roller into the sizing agent tank for high-temperature sizing agent coating, and the coated carbon fiber yarn is further tractioned by the guide roller and passes through the drying unit for fiber surface drying treatment.

[0014] Furthermore, in the above-mentioned device, the high-temperature sizing agent used in the sizing unit is a low-solids polyimide solution with a solids content of 3wt% to 6wt%.

[0015] Furthermore, in the above-mentioned device, the drying unit adopts radiant heating.

[0016] Furthermore, in the above-mentioned device, the impregnation unit includes a guide roller, a drive roller, a pressure roller, and an impregnation tank; wherein, the guide roller is used for pulling the carbon fiber yarn, the drive roller is driven by the main machine to drive the carbon fiber yarn forward, the pressure roller is used to squeeze the carbon fiber yarn and remove excess glue, and the impregnation tank is used to hold the impregnation glue; the guide roller, drive roller, and pressure roller are connected to the main machine frame in sequence, the pressure roller is installed at the bottom of the impregnation tank, and the impregnation tank is connected to the main machine frame.

[0017] Furthermore, in the above-mentioned device, the winding unit also includes a paper pressing device and a device base; wherein, the paper pressing device is used to fix the release paper in the prepreg, the roller is used for the arrangement of carbon fiber yarns, and the paper pressing device and the roller are respectively connected to the device base.

[0018] Furthermore, in the above-mentioned apparatus, the impregnation unit uses a PMR type polyimide resin solution as the impregnation resin; the desizing unit uses acetone as the solvent for desizing; the carbon fiber is T300 grade carbon fiber, T700 grade carbon fiber, or T800 grade carbon fiber, and the fiber bundle is 3k, 6k, or 12k.

[0019] This invention discloses a method for preparing carbon fiber prepreg, employing an online surface treatment and impregnation device for carbon fiber, comprising:

[0020] The carbon fibers are placed on the yarn rack of the desizing unit;

[0021] The carbon fiber is introduced into a solvent tank containing a desizing solvent;

[0022] The desized carbon fiber is introduced into a sizing tank containing sizing solvent;

[0023] After the sized carbon fiber is dried, it is introduced into the impregnation tank containing resin solution in the impregnation unit.

[0024] One end of the carbon fiber yarn impregnated with resin solution is fixed to one side of the roller of the winding unit. Before fixing the yarn, the surface of the roller is covered with release paper.

[0025] Configure parameters;

[0026] According to the set parameters, carbon fiber yarns are evenly distributed and wound up on the surface of the release paper to produce carbon fiber prepreg.

[0027] The advantages of this invention compared to the prior art are as follows:

[0028] (1) The present invention adopts a modular design method to realize the integration of online carbon fiber processing, re-sizing and impregnation processes, and can select functional modules as needed to achieve different functional requirements;

[0029] (2) The present invention adopts a continuous processing method of online desizing and resizing, and at the same time assists in the in-situ radiation heating method, which realizes the effective removal of high boiling point solvents after carbon fiber resizing, which is beneficial to the effective control of the subsequent composite material molding quality.

[0030] (3) The present invention adopts an integrated design of carbon fiber surface treatment and resin impregnation, which realizes the online treatment of carbon fiber sizing agent during the preparation of polyimide prepreg, thereby reducing the degree of damage to carbon fiber and improving the preparation efficiency. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the carbon fiber online surface treatment and impregnation device of the present invention. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] This embodiment provides an online surface treatment and impregnation device for carbon fiber, including: a control and drive unit, a desizing unit, a sizing unit, an impregnation unit, a winding unit, and a main frame, wherein: the desizing unit, the sizing unit, the impregnation unit, and the winding unit are sequentially installed on the main frame;

[0034] The desizing unit removes the sizing agent from the surface of the carbon fiber using a solvent;

[0035] The sizing unit re-coates a high-temperature sizing agent onto the carbon fiber surface after the sizing agent has been removed;

[0036] The impregnation unit impregnates the sized carbon fibers with polyimide resin.

[0037] The winding unit, including a roller, uniformly arranges the resin-impregnated carbon fibers according to the control signal from the control and drive unit to obtain carbon fiber reinforced polyimide wet prepreg.

[0038] The control and drive unit controls the winding unit, including the carbon fiber yarn tension, prepreg width, heating temperature, and drum speed.

[0039] The carbon fiber online surface treatment and impregnation device in this embodiment can select different module combinations according to actual needs to prepare polyimide prepregs with different carbon fiber treatment states.

[0040] Preferably, the control and drive unit includes a parameter control interface and a servo driver; wherein, the parameter control interface sets parameters such as roller speed, roller lateral movement speed, yarn tension, heating temperature and prepreg width, and the servo driver drives the roller to rotate according to the set parameters.

[0041] Preferably, the desizing unit includes a yarn frame, a guide roller, and a solvent tank; wherein, the yarn frame is used to install carbon fibers, the guide roller is used to guide the direction of the carbon fibers, and the solvent tank is used to hold the solvent for carbon fiber surface treatment. The components are connected to the main frame in the order of use. During use, the carbon fiber yarn installed on the yarn frame is guided into the solvent tank by the guide roller for carbon fiber surface solvent treatment.

[0042] Preferably, the sizing unit includes a guide roller, a sizing agent tank, and a drying unit; wherein, the guide roller is used for traction of carbon fiber yarn, the sizing agent tank is used to hold high-temperature sizing agent, and the drying unit is used to remove the solvent remaining on the surface of the carbon fiber yarn after the high-temperature sizing agent is applied; the guide roller, the sizing agent tank, and the drying unit are connected on the main frame in the order of use; during use, the carbon fiber yarn treated in the solvent tank is tractioned by the guide roller into the sizing agent tank for high-temperature sizing agent coating, and the coated carbon fiber yarn is further tractioned by the guide roller and passes through the drying unit for fiber surface drying treatment.

[0043] Preferably, the high-temperature sizing agent used in the sizing unit is a low-solids polyimide solution with a solids content of 3wt% to 6wt%.

[0044] Preferably, the drying unit uses radiant heating.

[0045] Preferably, the impregnation unit includes a guide roller, a drive roller, a pressure roller, and an impregnation tank; wherein, the guide roller is used for pulling the carbon fiber yarn, the drive roller is driven by the main machine to move the carbon fiber yarn forward, the pressure roller is used to squeeze the carbon fiber yarn and remove excess glue, and the impregnation tank is used to hold the impregnation glue; the guide roller, drive roller, and pressure roller are connected to the main machine frame in sequence, the pressure roller is installed at the bottom of the impregnation tank, and the impregnation tank is connected to the main machine frame.

[0046] Preferably, the winding unit further includes a paper pressing device and a device base; wherein the paper pressing device is used to fix the release paper in the prepreg, the roller is used for the arrangement of carbon fiber yarns, and the paper pressing device and the roller are respectively connected to the device base.

[0047] Preferably, the impregnation unit uses a PMR type polyimide resin solution as the impregnation resin; the desizing unit uses acetone as the solvent for desizing, and the carbon fibers are T300 grade carbon fibers, T700 grade carbon fibers, or T800 grade carbon fibers, with fiber bundles of 3k, 6k, or 12k.

[0048] This embodiment provides a method for preparing carbon fiber prepreg, employing an online surface treatment and impregnation device for carbon fiber, including:

[0049] The carbon fibers are placed on the yarn rack of the desizing unit;

[0050] The carbon fiber is introduced into a solvent tank containing a desizing solvent;

[0051] The desized carbon fiber is introduced into a sizing tank containing sizing solvent;

[0052] After the sized carbon fiber is dried, it is introduced into the impregnation tank containing resin solution in the impregnation unit.

[0053] One end of the carbon fiber yarn impregnated with resin solution is fixed to one side of the roller of the winding unit. Before fixing the yarn, the surface of the roller is covered with release paper.

[0054] Configure parameters;

[0055] According to the set parameters, carbon fiber yarns are evenly distributed and wound up on the surface of the release paper to produce carbon fiber prepreg.

[0056] Example 1

[0057] MT300 carbon fiber is placed on the yarn rack of the desizing unit. The fiber is guided into the solvent tank via guide rollers. An appropriate amount of acetone is poured into the solvent tank to ensure that the carbon fiber is completely immersed in the acetone solvent. Then, the fiber is guided into the sizing tank via guide rollers of the sizing unit. A 3wt% solids content SPI polyimide solution is poured into the sizing tank. After passing through the drying column, the fiber is introduced into the impregnation tank of the impregnation unit. The impregnation tank uses 906 polyimide resin solution. After passing through the impregnation tank, one end of the resin-impregnated carbon fiber yarn is fixed to one side of the roller in the take-up unit. Before fixing the yarn, the surface of the roller is covered with release paper. The carbon fiber yarn is evenly distributed and wound up on the surface of the release paper. During the winding process, the yarn tension is controlled at 5N, the roller speed is set to 4r / min, the cross-thread movement speed is 4.94mm / min, the width is 800mm, and the drying temperature is set to 150℃. After being laid out to a width of 800 mm, the prepreg is cut parallel to the width direction to obtain a certain length of prepreg. The prepreg is then air-dried at room temperature for 24-48 hours until the surface is no longer sticky. A thin film is then applied to the surface to obtain the prepreg. The polyimide composite material prepared using this prepreg has an interlaminar shear strength of 120 MPa and a 0° tensile strength of 1700 MPa.

[0058] Example 2

[0059] MT700 carbon fiber is placed on the yarn rack of the desizing unit. The fiber is guided into the solvent tank via guide rollers. An appropriate amount of acetone is poured into the solvent tank to ensure that the carbon fiber is completely immersed in the acetone solvent. Then, the fiber is guided into the sizing tank via guide rollers of the sizing unit. A 3wt% solids content SPI polyimide solution is poured into the sizing tank. After passing through the drying column, the fiber is introduced into the impregnation tank of the impregnation unit. The impregnation tank uses 906 polyimide resin solution. After passing through the impregnation tank, one end of the resin-impregnated carbon fiber yarn is fixed to one side of the roller in the take-up unit. Before fixing the yarn, the surface of the roller is covered with release paper. The carbon fiber yarn is evenly distributed and wound up on the surface of the release paper. During the winding process, the yarn tension is controlled at 5N, the roller speed is set to 4r / min, the cross-thread movement speed is 4.94mm / min, the width is 800mm, and the drying temperature is set to 150℃. After being laid out to a width of 800 mm, the prepreg is cut parallel to the width direction to obtain a certain length of prepreg. The prepreg is then left to air dry at room temperature for 24-48 hours until the surface is no longer sticky. After this, a thin film is applied to the surface to obtain the prepreg. The polyimide composite material prepared using this prepreg has an interlaminar shear strength of 98 MPa and a 0° tensile strength of 2000 MPa.

[0060] Example 3

[0061] TG800 carbon fiber is placed on the yarn rack of the desizing unit. The fiber is guided into the solvent tank via guide rollers. An appropriate amount of acetone is poured into the solvent tank to ensure that the carbon fiber is completely immersed in the acetone solvent. Then, the fiber is guided into the sizing tank via guide rollers of the sizing unit. A 3wt% solids content SPI polyimide solution is poured into the sizing tank. After passing through the drying column, the fiber is introduced into the impregnation tank of the impregnation unit. The impregnation tank uses 906 polyimide resin solution. After passing through the impregnation tank, one end of the resin-impregnated carbon fiber yarn is fixed to one side of the roller in the winding unit. Before fixing the yarn, the surface of the roller is covered with release paper. The carbon fiber yarn is evenly wound and arranged on the surface of the release paper. During the arrangement process, the yarn tension is controlled at 5N, the roller speed is set to 4r / min, the cross-thread movement speed is 4.94mm / min, the width is 800mm, and the drying temperature is set to 150℃. After being laid out to a width of 800 mm, the prepreg is cut parallel to the width direction to obtain a certain length of prepreg. The prepreg is then air-dried at room temperature for 24-48 hours until the surface is no longer sticky. A thin film is then applied to the surface to obtain the prepreg. The polyimide composite material prepared using this prepreg has an interlaminar shear strength of 105 MPa and a 0° tensile strength of 2200 MPa.

[0062] Example 4

[0063] TG800 carbon fiber is placed on the yarn rack of the desizing unit. The fiber is guided into the solvent tank by a guide roller. An appropriate amount of acetone is poured into the solvent tank to ensure that the carbon fiber is completely immersed in the acetone solvent. After passing through the desizing tank, the carbon fiber is directly introduced into the impregnation tank of the impregnation unit through the drying channel. The impregnation tank uses 906 polyimide resin solution. After passing through the impregnation tank, one end of the resin-impregnated carbon fiber yarn is fixed to one side of the roller in the winding unit. Before fixing the yarn, the surface of the roller is covered with release paper. The carbon fiber yarn is evenly wound and arranged on the surface of the release paper. During the arrangement process, the yarn tension is controlled at 5N, the roller speed is set to 4r / min, the cross-thread movement speed is 4.94mm / min, and the width is 800mm. After the width reaches 800mm, the prepreg is cut parallel to the width direction to obtain a certain length of prepreg. The prepreg is then dried at room temperature for 24h~48h. After the surface of the prepreg is no longer sticky, a film is covered on its surface to obtain the prepreg. The interlaminar shear strength of the polyimide composite material prepared using this prepreg is 100 MPa, and the tensile strength at 0° is 2300 MPa.

[0064] Example 5

[0065] TG800 carbon fiber was placed on the yarn rack of the desizing unit, and the fiber was directly introduced into the impregnation tank of the impregnation unit. The impregnation tank used a 906 polyimide resin solution. After impregnation, one end of the resin-impregnated carbon fiber yarn was fixed to one side of the roller in the winding unit. Before fixing the yarn, the roller surface was covered with release paper. The carbon fiber yarn was evenly wound and arranged on the release paper surface. During the arrangement process, the yarn tension was controlled at 5N, the roller speed was set to 4 r / min, the cross-thread movement speed was 4.94 mm / min, and the width was 800 mm. After reaching a width of 800 mm, the prepreg was cut parallel to the width direction to obtain a certain length of prepreg. The prepreg was then air-dried at room temperature for 24-48 hours until the surface was no longer sticky. A thin film was then applied to the surface to obtain the prepreg. The polyimide composite material prepared using this prepreg exhibited an interlaminar shear strength of 90 MPa and a 0° tensile strength of 2350 MPa.

[0066] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0067] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. An online surface treatment and impregnation device for carbon fiber, characterized in that, include: The system includes a control and drive unit, a desizing unit, a sizing unit, an impregnation unit, a winding unit, and a main frame, wherein the desizing unit, sizing unit, impregnation unit, and winding unit are sequentially mounted on the main frame. The desizing unit removes the sizing agent from the surface of the carbon fiber using a solvent; The sizing unit re-coates a high-temperature sizing agent onto the carbon fiber surface after the sizing agent has been removed; The impregnation unit impregnates the sized carbon fibers with polyimide resin. The winding unit, including a roller, uniformly arranges the resin-impregnated carbon fibers according to the control signal from the control and drive unit to obtain carbon fiber reinforced polyimide wet prepreg. The control and drive unit controls the winding unit, including the carbon fiber yarn tension, prepreg width, heating temperature, and drum speed. The sizing unit uses a high-temperature sizing agent that is a low-solids polyimide solution with a solids content of 3wt%~6wt%. The impregnation unit uses a PMR type polyimide resin solution as the impregnation resin. The desizing unit includes a yarn frame, a guide roller, and a solvent tank. The yarn frame is used to install carbon fibers, the guide roller is used to guide the direction of the carbon fibers, and the solvent tank is used to hold the solvent for carbon fiber surface treatment. The components are connected to the main frame in the order of use. During use, the carbon fiber yarn installed on the yarn frame is guided into the solvent tank by the guide roller for carbon fiber surface solvent treatment. The sizing unit includes a guide roller, a sizing agent tank, and a drying unit. The guide roller is used for drawing carbon fiber yarn, the sizing agent tank is used to hold high-temperature sizing agent, and the drying unit is used to remove the solvent remaining on the surface of the carbon fiber yarn after the high-temperature sizing agent is applied. The guide roller, sizing agent tank, and drying unit are connected to the main frame in the order of use. During use, the carbon fiber yarn treated in the solvent tank is drawn into the sizing agent tank by the guide roller for high-temperature sizing agent coating. After coating, the carbon fiber yarn is drawn through the drying unit by the guide roller for fiber surface drying.

2. The online surface treatment and impregnation device for carbon fiber according to claim 1, characterized in that: The control and drive unit includes a parameter control interface and a servo driver; wherein, the parameter control interface is used to set parameters such as roller speed, roller lateral movement speed, yarn tension, heating temperature and prepreg width, and the servo driver drives the roller to rotate according to the set parameters.

3. The online surface treatment and impregnation device for carbon fiber according to claim 2, characterized in that: The drying unit uses radiant heating.

4. The online surface treatment and impregnation device for carbon fiber according to claim 1, characterized in that: The impregnation unit includes a guide roller, a drive roller, a pressure roller, and an impregnation tank. The guide roller is used to pull the carbon fiber yarn, the drive roller is driven by the main machine to move the carbon fiber yarn forward, the pressure roller is used to squeeze the carbon fiber yarn and remove excess adhesive, and the impregnation tank is used to hold the impregnation adhesive. The guide roller, drive roller, and pressure roller are connected to the main machine frame in sequence, the pressure roller is installed at the bottom of the impregnation tank, and the impregnation tank is connected to the main machine frame.

5. The online surface treatment and impregnation device for carbon fiber according to claim 1, characterized in that: The winding unit further includes a paper pressing device and a device base; wherein, the paper pressing device is used to fix the release paper in the prepreg, and the roller is used for the arrangement of carbon fiber yarns, and the paper pressing device and the roller are respectively connected to the device base.

6. The online surface treatment and impregnation device for carbon fiber according to claim 1, characterized in that: The solvent used in the desizing unit is acetone, and the carbon fiber is T300 grade carbon fiber, T700 grade carbon fiber or T800 grade carbon fiber, with fiber bundles of 3k, 6k or 12k.

7. A method for preparing carbon fiber prepreg, characterized in that: The online surface treatment and impregnation apparatus for carbon fiber as described in any one of claims 1 to 6 includes: The carbon fibers are placed on the yarn rack of the desizing unit; The carbon fiber is introduced into a solvent tank containing a desizing solvent; The desized carbon fiber is introduced into a sizing tank containing sizing solvent; After the sized carbon fiber is dried, it is introduced into the impregnation tank containing resin solution in the impregnation unit. One end of the carbon fiber yarn impregnated with resin solution is fixed to one side of the roller of the winding unit. Before fixing the yarn, the surface of the roller is covered with release paper. Configure parameters; According to the set parameters, carbon fiber yarns are evenly distributed and wound up on the surface of the release paper to produce carbon fiber prepreg.

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