WO2021174519A1

WO2021174519A1 - Carbon fiber-pmi composite pipeline and preparation method therefor

Info

Publication number: WO2021174519A1
Application number: PCT/CN2020/078142
Authority: WO
Inventors: 李道学; 沈志峰
Original assignee: 广东宇顺新材料科技有限公司
Priority date: 2020-03-04
Filing date: 2020-03-06
Publication date: 2021-09-10
Also published as: CN111271527A

Abstract

A carbon fiber-PMI composite pipeline and a preparation method therefor, the carbon fiber-PMI composite pipeline comprising a pipe wall and a hollow cavity; the pipe wall of the carbon fiber-PMI composite pipeline is formed by coiling and compositing at least three carbon fiber layers and at least two layers of PMI films; the inner side and the outer side of each PMI film are carbon fiber layers, the base layer and the skin layer of the pipe wall are carbon fiber layers, and the thickness of each PMI film does not exceed 1 mm. The carbon fiber-PMI composite material having a multi-layer sandwich structure is employed as a pipe wall to construct a hollow pipeline structure. Therefore, the formed pipeline structure has excellent specific rigidity, specific strength and corrosion resistance. The inner space of the hollow pipe cavity of the carbon fiber-PMI composite pipeline may be reasonably utilized to store parts in the same design. In another aspect, the outer wall of the carbon fiber-PMI composite pipeline may also provide protection for the parts in the hollow pipe cavity. Thus, the possibility of parts being hit, eroded and aged by light is reduced, and the service life of the parts is extended.

Description

Carbon fiber-PMI composite pipe and preparation method thereof

Technical field

The invention belongs to the field of composite materials, and specifically relates to a carbon fiber-PMI composite pipe and a preparation method thereof.

Background technique

Carbon fiber is a special fiber composed of carbon elements, which has the characteristics of high temperature resistance, friction resistance, electrical conductivity, heat conduction and corrosion resistance. The shape of carbon fiber is fibrous, soft, and can be processed into various fabrics. Because of its graphite crystallite structure is preferentially oriented along the fiber axis, it has high strength and modulus along the fiber axis. Carbon fiber has a low density, so its specific strength and specific modulus are high. In the prior art, the main purpose of carbon fiber is to compound with foam, resin, metal, ceramics and carbon as a reinforcing material to produce advanced composite materials.

Polymethacrylimide (PMI) is a cross-linked foam with uniform pore size distribution, with excellent structural stability and high mechanical strength. PMI has higher specific strength, specific modulus, heat resistance and damp heat resistance than other polymer foam materials, as well as better high temperature creep resistance and dimensional stability. PMI is currently the foam material with the highest specific strength (strength/density) and specific modulus (modulus/density) in the world, and it has excellent high temperature resistance and dimensional stability. It is ideal for manufacturing lightweight and high-strength composite pipe walls. Core. In addition, due to the high closed cell rate of PMI, uniform pore size distribution, and low moisture absorption rate, the sandwich composite material used as the core material has much better durability and environmental resistance than honeycomb composite materials.

However, as a rigid foam plastic, PMI has no bendability at room temperature. This characteristic limits the application of PMI in the construction of special-shaped structures. In the prior art, if PMI needs to be composited to the surface of a curved substrate or a bent substrate, it is generally necessary to attach the PMI board to the substrate or mold at a high temperature to obtain a PMI preform with a profiled profile, or , Use cutting equipment to cut the surface of PMI according to the required profile. Among the above-mentioned PMI pre-forming methods: the former generally requires additional pre-forming molds with specific shapes, and the investment of pre-forming molds increases production costs; while the latter requires editing specific surface machining parameters according to actual processing needs. However, this pre-forming method is not suitable for continuous mass production, and will produce a lot of scraps, cause waste of raw materials, and produce scrap processing or recycling procedures. In addition, the PMI preform prepared by the above method has low flexibility and universality, and can only be matched with a specific mold or substrate.

Summary of the invention

The purpose of the present invention is to provide a carbon fiber-PMI composite pipe and a preparation method thereof, so as to obtain a composite material pipe with good mechanical properties.

According to one aspect of the present invention, a carbon fiber-PMI composite pipe is provided: comprising a pipe wall and a hollow cavity. The pipe wall is formed by rolling and laminating at least three carbon fiber layers and at least two PMI films. Both the inner and outer sides are carbon fiber layers, and the base layer and skin layer of the tube wall are both carbon fiber layers, and the thickness of the PMI film does not exceed 1mm

The present invention uses carbon fiber-PMI composite material in a multi-layer sandwich structure as the pipe wall to construct a hollow pipe structure. The pipe structure formed thereby has excellent specific stiffness, specific strength and corrosion resistance, and can be widely used Various structural designs in various fields. In practical applications, the internal space of the hollow lumen of the carbon fiber-PMI composite pipe provided by the present invention can be used to accommodate parts of the same design. On the other hand, the outer wall of the carbon fiber-PMI composite pipe can also be placed in a hollow pipe. The parts in the cavity provide protection, reduce the possibility of impact, erosion, and aging of the parts, and extend the service life of the parts.

Preferably, the PMI film is made of 100% PMI.

Preferably, the thickness of the PMI film does not exceed 0.3 mm.

Unlike traditional PMI sheets, PMI films with a thickness of less than 1mm have a certain degree of curlability at room temperature. Using this kind of PMI film as the core material for preparing composite pipes, the PMI film can be directly attached to the contour of the substrate. It is compounded on the outside of the substrate, so that the mass-produced PMI film can be flexibly applied to a variety of composite pipes of different shapes. In addition, compared with the composite between the thick plates, the composite between the thin layers has a larger interlayer bonding force, and the bonding between the layers is tighter, and it is not easy to delaminate, which improves the integration and mechanical properties of the pipeline. Utilizing the excellent mechanical properties of PMI, in the alternate composite of PMI membrane and carbon fiber membrane to form the tube wall, the PMI membrane supports and strengthens the carbon fiber layer, so that the tube wall has high tensile resistance and pressure resistance. sex. In the pipe wall, the thickness of each layer of PMI film is relatively small. Therefore, the composite form of multi-layer PMI film can be used to make the pipe have greater mechanical strength. The increase in diameter limits the application scenarios of the pipeline.

Preferably, the PMI film is spirally compounded on the outer periphery of the inner carbon fiber layer.

Preferably, the shape is a vertical tube, or an arc tube, or a bent tube. Any pipe whose geometric centers of the radial cross-section are on the same straight line can be called a vertical pipe, and a pipe whose center of gravity is outside the pipe body and does not have a bent structure can be called an arc-shaped pipe, and the pipe body includes at least one All pipes with bent corners can be referred to as bent pipes.

The spiral composite method allows the PMI film to better adapt to different shapes of substrates, and can be closely attached to the surface of the substrate, avoiding the blind spots generated by the composite PMI film, so that various integrated moldings can be made Special-shaped pipes, especially pipes with bent tubes, do not need to set breakpoints at the bends, which avoids uncontrollable deformation and cracks in the pipeline due to different degrees of stress concentration at the breakpoints.

Optionally, the PMI film is directly wrapped around the outer periphery of the inner carbon fiber layer. Direct coating means that the PMI film is directly wrapped around the periphery of the carbon fiber layer in a manner similar to cigarettes.

According to another aspect of the present invention, there is provided a method for preparing the above-mentioned carbon fiber-PMI composite pipe, which includes the following steps: S1. Wrap carbon fiber on the surface of the mandrel mold as a base layer; S2. Combine the PMI film and the carbon fiber at room temperature. The layer is wrapped around the periphery of the base layer to form a sandwich structure on the periphery of the base layer, the sandwich structure is a multilayer sandwich structure containing at least two layers of PMI film; S3. A carbon fiber layer is wrapped around the periphery of the sandwich structure to form a skin layer; S4. Shape and compound the adjacent layered structures that make up the pipe wall; S5. Remove the mandrel mold to prepare a carbon fiber-PMI composite pipe.

Preferably, in S3, the PMI film is wound around the periphery of the carbon fiber layer adjacent to the inner side thereof in a spiral winding manner.

Optionally, in S3, the operation of winding the PMI film is specifically: coating viscose on the periphery of the carbon fiber layer wound on the mandrel mold, and then, at room temperature, spirally winding the PMI film on the periphery of the carbon fiber layer .

Optionally, in S3, the operation of winding the PMI film is specifically: pre-dipping the PMI film in the adhesive, and then, at room temperature, spirally winding the PMI film covered with the adhesive on the mandrel mold On the periphery of the carbon fiber layer.

In the above preparation process, the mass-produced PMI film can be directly covered on the surface of the substrate under normal temperature conditions, without the need to add a heating device or a mechanical cutting device to preform the PMI sheet. For those involving PMI core material For the production of composite materials, the production process is simplified, the production cycle is shortened, and the production cost and energy consumption are reduced, which is beneficial to increase the production speed and yield.

Description of the drawings

Figure 1 is a three-dimensional schematic diagram of the natural state of the PMI plate and PMI film at room temperature;

Fig. 2 is a schematic diagram of winding and compounding the PMI film on the carbon fiber layer in the process of manufacturing the vertical pipe in Example 1;

3 is a schematic diagram of the overall structure and the interlayer structure of the vertical pipe made in Example 1;

Figure 4 is a schematic cross-sectional view of a carbon fiber-PMI composite pipe made in Comparative Example 2

Fig. 5 is a schematic diagram showing that the PMI film is directly coated and compounded on the carbon fiber layer in the process of manufacturing the vertical pipe with a square cross-section in Example 2;

6 is a schematic diagram of the overall structure and interlayer structure of the arc-shaped pipe made in Example 3;

FIG. 7 is a schematic diagram of the overall structure of the three-sided bent pipe manufactured in Embodiment 4. FIG.

The corresponding relationship of the reference signs in the above figure is as follows: 1. PMI sheet, 2. Carbon fiber layer, 3. PMI film layer, 4. PMI inner core, 5. Straight rod mold.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not All examples.

When describing the preferred embodiments shown in the drawings, special terms may be used for the purpose of clarity; however, those disclosed in this specification are not intended to be limited to the particular term selected; and it should be understood that each A particular element includes all equivalent technologies that have the same function, operate in a similar manner, and achieve similar effects.

Example 1

Main materials: carbon fiber, PMI film.

How to obtain the PMI film: Take the PMI sheet 1 as the raw material and cut to obtain a PMI film with a thickness of 0.2 mm. As shown in Figure 1, the PMI sheet 1 before cutting is a hard sheet, which does not have bendability and curlability at room temperature, and the PMI film obtained by cutting, when its thickness reaches 1mm or less, At room temperature, it has a certain degree of crimpability and can be crimped into a roll with a certain toughness as shown in Figure 1. However, the nature of its material has not changed, which means that the PMI film retains the outstanding characteristics of PMI. Structural stability and mechanical strength.

Preparation of the vertical pipeline:

S1. Coat a release agent on the surface of a straight rod mold 5 with a circular cross section, fit the surface of the mold, and use carbon fiber to wind the mold, thereby constructing the first carbon fiber layer 2 as the base layer of the tube wall;

S2. Expansion of the sandwich structure

S2.1 Coating resin on the surface of the carbon fiber layer 2 as the base layer, and use carbon fibers to wrap around the periphery of the base layer, thereby constructing two carbon fiber layers 2 on the periphery of the base layer;

S2.2 The surface of the outermost carbon fiber layer 2 of the semi-finished product prepared in the previous step is coated with resin. As shown in Figure 2, the PMI film is used to attach and wrap around the outer carbon fiber layer 2 on the outermost carbon fiber layer 2 of the semi-finished product. A layer of PMI film 3 is constructed on the periphery of, and the PMI film 3 formed therefrom has a spiral pattern;

S2.3 The surface of the outermost PMI film layer 3 of the semi-finished product prepared in the previous step is coated with resin, and carbon fibers are used to stick and wrap around the periphery of the PMI film layer 3, thereby constructing another layer of carbon fiber layer 2 on the periphery of the semi-finished product. ；

S2.4 repeat S2.2-S2.3 three times;

S3. The surface of the outermost carbon fiber layer 2 of the semi-finished product obtained in the previous step is coated with resin, and the carbon fiber is attached and wound on the periphery of the semi-finished product, thereby constructing another layer of carbon fiber layer 2 on the periphery of the semi-finished product as the tube wall Skin layer

S4. Ultraviolet rays are irradiated to cross-link and cure the resin bonding each layered structure to shape the tube wall. In other embodiments, heating can also be used to cross-link and cure the resin;

S5. Take off the straight rod-shaped mold to make a vertical pipe.

The vertical pipe made in this embodiment is a pipe structure with a circular cross-section, an inner diameter of 1 cm, and a total wall thickness of 1.6 mm-1.7 mm. The overall structure and the interlayer structure of the pipe wall are shown in Figure 3 As shown, the interlayer structure of the pipe wall is: 3 layers of carbon fiber layers 2-1 layers of PMI membrane layers 3-1 layers of carbon fiber layers 2-1 layers of PMI membrane layers 3-1 layers of carbon fiber layers 2-1 layers of PMI membrane layers 3- 1 layer of carbon fiber layer 2-1 layer of PMI film layer 3-2 layer of carbon fiber layer 2. Since each layer of the pipe wall adopts continuous material to be compounded on the periphery of the base material in a winding manner, the pipe wall surface of the vertical pipe prepared in this embodiment has no obvious layer indirection point. In practical applications, the number of layers of the core structure and the thickness of each layered structure can be adjusted within an appropriate range as required.

Comparative Example 1

Main materials: carbon fiber, PMI film.

The method of obtaining the PMI film: similar to Example 1, the PMI plate is used as a raw material, and a PMI film with a thickness of 0.2 mm is obtained by cutting. The PMI film has a certain degree of curlability at room temperature.

Preparation of the vertical pipeline:

S2. Expansion of the sandwich structure

S2.1 Coating resin on the surface of the carbon fiber layer 2 as the base layer, and use carbon fibers to wrap around the periphery of the base layer, thereby constructing three carbon fiber layers 2 on the periphery of the base layer;

S2.2 The surface of the outermost carbon fiber layer 2 of the semi-finished product obtained in the previous step is coated with resin, and the PMI film is used to attach and wrap around the semi-finished product, thereby constructing 4 layers of PMI film 3 on the semi-finished product;

S2.3 The surface of the outermost PMI film layer 3 of the semi-finished product prepared in the previous step is coated with resin, and carbon fibers are used to stick and wrap around the periphery of the semi-finished product, thereby constructing three carbon fiber layers 2 on the periphery of the semi-finished product;

S3. The surface of the outermost carbon fiber layer 2 of the semi-finished product obtained in the previous step is coated with resin, and the carbon fiber is attached and wound around the periphery of the semi-finished product, thereby constructing a carbon fiber layer 2 on the periphery of the semi-finished product to serve as the tube wall mask. Cortex

S5. Take off the straight rod-shaped mold to make a vertical pipe.

The vertical pipe prepared in this embodiment is a pipe structure with a circular cross section, an inner diameter of 1 cm, and a total wall thickness of 1.6 mm-1.7 mm. The interlayer structure of the pipe wall is: 4 layers of carbon fiber layers 2-4 Layer PMI film layer 3-4 layer carbon fiber layer 2.

Comparative Example 2

Main materials: carbon fiber, PMI sheet1.

Preparation of solid vertical rod-shaped structure:

S1. Use cutting equipment to mill the PMI sheet 1 into a cylindrical structure with a bottom radius of 0.5 cm as the PMI inner core 4;

S2. Coating resin on the periphery of the PMI inner core 4, and use carbon fiber to wind around the periphery of the PMI inner core 4 to form the first carbon fiber layer 2;

S3. Coating resin on the periphery of the first layer of carbon fiber layer 2, and using carbon fibers to wind around the periphery of the first layer of carbon fiber layer 2 to form a second layer of carbon fiber layer 2;

S4. Repeat S3 six times until the construction of the eighth carbon fiber layer 2 is completed;

S5. Ultraviolet rays are irradiated to cross-link and cure the resins that adhere to each layered structure to shape the tube wall. In other embodiments, heating can also be used to cross-link and cure the resin to obtain a solid vertical rod-shaped structure.

The solid vertical rod-shaped structure made in this embodiment is a pipe structure with a circular cross-section, a diameter of the PMI core 4 of 1 cm, and a total thickness of the rod wall of 1.6 mm-1.7 mm. As shown in Figure 4, the rod The core is PMI sheet 1, and the interlayer structure of the rod wall is composed of 8 carbon fiber layers 2.

Comparative Example 3

Main material: carbon fiber

Preparation of the vertical pipeline:

S2. Coating resin on the surface of the carbon fiber layer 2 as the base layer, and using carbon fibers to wind around the foam core material to form the first carbon fiber layer 2;

S3. Coating resin on the periphery of the first layer of carbon fiber layer 2, using carbon fibers to wind around the periphery of the first carbon fiber layer 2 to form a second layer of carbon fiber layer 2;

S4. Repeat S3 ten times until the construction of the twelfth carbon fiber layer 2 is completed;

S5. Ultraviolet radiation to cross-link and cure the resin bonding each layered structure to shape the tube wall. In other embodiments, heating can also be used to cross-link and cure the resin;

S6. Take off the straight rod-shaped mold to make a vertical pipe.

The vertical pipe prepared in this embodiment is a pipe structure with a circular cross section, an inner diameter of 1 cm, and a total wall thickness of 1.6 mm-1.7 mm. The interlayer structure of the pipe wall is composed of 12 carbon fiber layers 2.

Test case

In this example, the carbon fiber-PMI composite vertical pipes prepared in Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were used as test objects, and a pressure-bearing experiment was set up.

Experiment setting method:

In this embodiment, four experimental groups are set, one type of test subject is one experimental group, each experimental group is set to 5 repetitions, and each test subject is one repetition. Two quarter points located at the two ends of the test object’s tube body are used as the force points. At the two force points, a force of the same magnitude and downward direction is applied to the test object to be able to crush the parameters. The minimum value of the unilateral force of the test object is taken as the pressure limit of the test object.

Experimental result

The respective pressure-bearing limits of the test subjects in this embodiment are shown in Table 1, arranged according to the size of the pressure-bearing limit: Example 1>Comparative Example 1>Comparative Example 2>Comparative Example 3. From the pressure-bearing experiment test of this example, it can be concluded that the pressure-bearing limit of the carbon fiber vertical pipe prepared in Comparative Example 3 is the smallest value among all the test subjects, which proves that the PMI and the carbon fiber membrane are combined to prepare the composite material , PMI and carbon fiber can support each other and strengthen each other, so that the composite material can achieve stronger mechanical strength compared with the two alone; in terms of the pressure limit, compare the corresponding value of Example 2 Both are smaller than the corresponding values of Example 1 and Comparative Example 1. However, as far as the PMI material is concerned, the PMI of Comparative Example 2 is used as the solid core material, so the solid vertical rod-shaped structure produced in Comparative Example 2 The amount of PMI used in the test is definitely the largest among all the participants, which proves that the composite of carbon fiber and PMI in the form of a sandwich can effectively improve the mechanical strength of the composite while saving PMI materials; and the embodiment 1 is compared with the pressure limit of the test object made in Comparative Example 1. The thickness of the tube wall, the type of layer structure constituting the tube wall and the corresponding number of layers are the same, and only the row of each layer structure is the same. The layout method is different, but the pressure limit of the test object prepared in Example 1 is significantly higher than the pressure limit of the test object prepared in Comparative Example 1. It can be proved that for the PMI-carbon fiber composite material with a sandwich structure In other words, the more layers of the sandwich, the greater the interlayer bonding force between the thin layers in the composite material, and the tighter bonding between the layers, so that the composite material has greater mechanical strength.

Table 1 The pressure limit value of each test object in this embodiment

Example 2

Main materials: carbon fiber, PMI film.

The method of obtaining the PMI film: similar to Example 1, the PMI plate is used as a raw material, and a PMI film with a thickness of 0.3 mm is obtained by cutting. The PMI film has a certain degree of curlability at room temperature.

The pretreatment method of carbon fiber: carbon fiber is made into carbon fiber prepreg.

Preparation of the vertical pipeline:

S1. Coat a release agent on the surface of a straight rod type mold 5 with a square cross-section, fit the surface of the mold, and pave carbon fiber prepreg on the surface of the mold to construct a carbon fiber layer 2 as the tube wall base of the tube wall , The first layer of carbon fiber layer 2 thus constructed serves as the base layer of the tube wall;

S2. Expansion of the sandwich structure

S2.1 Coating resin on the surface of the carbon fiber layer 2 as the base layer, and spread the carbon fiber prepreg on the periphery of the base layer, thereby constructing a carbon fiber layer 2 on the periphery of the base layer;

S2.2 The surface of the outermost carbon fiber layer 2 of the semi-finished product obtained in the previous step is coated with resin. Construct a layer of PMI film 3 on the periphery;

S2.3 Coat the surface of the outermost PMI film layer 3 of the semi-finished product obtained in the previous step with resin, and spread the carbon fiber prepreg on the periphery of the semi-finished product, thereby constructing two carbon fiber layers 2 on the periphery of the semi-finished product;

S2.4 repeat S2.2-S2.3 once;

S3. The surface of the outermost carbon fiber layer 2 of the semi-finished product prepared in the previous step is coated with resin, the carbon fiber prepreg is laid on the periphery of the semi-finished product, and a carbon fiber layer 2 is constructed on the periphery of the semi-finished product to serve as the tube wall mask. Cortex

S4. Heating to cross-link and cure the resin bonding each layered structure to shape the tube wall. In other embodiments, ultraviolet light can also be used to cross-link and cure the resin;

S5. Take off the straight rod-shaped mold to make a vertical pipe.

The vertical pipe prepared in this embodiment is a pipe structure with a square cross section and a total thickness of the pipe wall of 1.3mm-1.6mm. The interlayer structure of the pipe wall is: 2 layers of carbon fiber layers and 2 layers of PMI film layers 3-2 layer of carbon fiber layer 2-1 layer of PMI film layer 3-3 layer of carbon fiber layer 2. In practical applications, the number of layers of the core structure and the thickness of each layered structure can be adjusted within an appropriate range as required.

Example 3

Main materials: carbon fiber, PMI film.

The method of obtaining the PMI film: similar to Example 1, the PMI plate is used as a raw material, and a PMI film with a thickness of 1 mm is obtained by cutting. The PMI film has a certain degree of curlability at room temperature.

Pretreatment method of PMI membrane: Pre-dip the PMI membrane in liquid high-energy glue.

Preparation of curved pipe:

S1. Coat the mold release agent on the surface of the arc-shaped rod-shaped mold with a circular cross-section, fit the surface of the mold, and spread the carbon fiber prepreg on the surface of the mold. The first layer of carbon fiber layer 2 thus constructed is used as The basal layer of the tube wall;

S2. Expansion of pipe wall

S2.2 Fit the contour of the semi-finished product made in the previous step, and wind the PMI film around the semi-finished product, thereby constructing a layer of PMI film 3 around the semi-finished product;

S2.3 Fit the contour of the semi-finished product obtained in the previous step, and pave the carbon fiber prepreg on the periphery of the semi-finished product, thereby constructing a carbon fiber layer 2 on the periphery of the semi-finished product;

S2.4 repeat S3.2-S3.3 twice;

S4. Heating to cross-link and cure the resin that adheres to the core layers to shape the tube wall. In other embodiments, ultraviolet light can also be used to cross-link and cure the resin;

S5. Take off the arc-shaped rod-shaped mold to obtain an arc-shaped pipe.

The arc-shaped pipe prepared in this embodiment is a pipe structure with a circular cross-section and a total thickness of the pipe wall of 3.6mm-3.9mm. The overall structure is shown in Figure 6, and the interlayer structure of the pipe wall is: 2 Layer carbon fiber layer 2-1 layer PMI film layer 3-1 layer carbon fiber layer 2-1 layer PMI film layer 3-1 layer carbon fiber layer 2-1 layer PMI film layer 3-2 layer carbon fiber layer 2. In practical applications, the number of layers of the core structure and the thickness of each layered structure can be adjusted within an appropriate range as required.

Example 4

Main materials: carbon fiber, PMI film.

The method of obtaining the PMI film: similar to Example 1, the PMI plate is used as a raw material, and a PMI film with a thickness of 0.8 mm is obtained by cutting. The PMI film has a certain degree of curlability at room temperature.

The pretreatment method of carbon fiber and PMI membrane: pre-soak the carbon fiber and PMI membrane in liquid high-energy glue.

Preparation of three-sided bending pipe:

S1. In this embodiment, the mold is a triangular mold constructed by three straight rods with a circular cross-section through a combination of connecting parts. The mold surface is coated with a release agent to fit the surface of the mold, and carbon fiber is used to wind the mold. The constructed first layer of carbon fiber layer 2 serves as the base layer of the tube wall;

S2. Expansion of pipe wall

S2.1 Fit the outer contour of the base layer made in the previous step, and wind the carbon fiber around the semi-finished product, thereby constructing a carbon fiber layer 2 around the semi-finished product;

S2.3 Fit the contour of the semi-finished product made in the previous step, and wind the carbon fiber around the semi-finished product, thereby constructing two carbon fiber layers 2 on the semi-finished product's periphery;

S2.4 repeat S3.2-S3.3 twice;

S3. Fit the contour of the semi-finished product made in the previous step, wind the carbon fiber around the semi-finished product, and build a carbon fiber layer 2 on the semi-finished product as the skin layer of the pipe wall;

S4. Ultraviolet light irradiation to cross-link and cure the resin bonding each layered structure to shape the tube wall. In other embodiments, heating can also be used to cross-link and cure the resin;

S5. Remove the arc-shaped rod-shaped mold from the opening of the pipe to obtain an arc-shaped pipe.

The three-sided bent pipe made in this embodiment has no pipe breaks at the bends, and is a pipe structure with a circular cross section and a total thickness of the pipe wall of 3.3 mm-3.5 mm. The overall structure is shown in the figure As shown in 6, the interlayer structure of the pipe wall is: 2 layers of carbon fiber layer, 2-1 layer of PMI film layer, 3-2 layer of carbon fiber layer, 2-1 layer of PMI film layer, 3-2 layer of carbon fiber layer, 2-1 layer of PMI film layer 3-3 layers of carbon fiber layer 2. In practical applications, the number of layers of the core structure and the thickness of each layered structure can be adjusted within an appropriate range as required.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out. Modification or equivalent replacement without departing from the essence and scope of the technical solution of the present invention.

Claims

A carbon fiber-PMI composite pipe, which is characterized in that it comprises a pipe wall and a hollow cavity. The pipe wall is formed by rolling and compounding at least three carbon fiber layers and at least two layers of PMI film, and the inner side of each layer of the PMI film and The outer side is the carbon fiber layer, and the base layer and the skin layer of the tube wall are both the carbon fiber layer, and the thickness of the PMI film does not exceed 1 mm.
The carbon fiber-PMI composite pipe according to claim 1, wherein the PMI film is made of 100% PMI.
The carbon fiber-PMI composite pipe according to claim 2, wherein the thickness of the PMI film does not exceed 0.3 mm.
The carbon fiber-PMI composite pipe according to claim 1, wherein the PMI film is spirally wound around the inner carbon fiber layer.
The carbon fiber-PMI composite pipe according to claim 4, characterized in that: the shape is a vertical tube, or an arc tube, or a bent tube.
The carbon fiber-PMI composite pipe according to claim 1, wherein the PMI film directly covers the outer periphery of the inner carbon fiber layer.
A method for preparing a carbon fiber-PMI composite pipe according to any one of claims 1 to 6, characterized in that it comprises the following steps:

S1. Wrap the carbon fiber layer on the surface of the mandrel mold as the base layer;

S2. At room temperature, the PMI film and carbon fiber are wound around the periphery of the base layer to form a sandwich structure on the periphery of the base layer, and the sandwich structure is a multilayer containing at least two layers of the PMI film Sandwich structure

S3. Wrap the carbon fiber layer around the periphery of the sandwich structure to form the skin layer;

S4. Shape and compound the adjacent layered structures that make up the tube wall;

S5. Take off the mandrel mold to prepare the carbon fiber-PMI composite pipe.
7. The preparation method according to claim 7, characterized in that: in the S3, the PMI film is wound around the outer periphery of the carbon fiber layer inside the PMI film in a spiral winding manner.
8. The preparation method according to claim 8, characterized in that, in the S3, the operation of winding the PMI film is specifically: coating viscose on the outer side of the carbon fiber layer, and then, at room temperature, making the The PMI film is spirally wound on the carbon fiber layer.
The preparation method according to claim 8, characterized in that, in the S3, the operation of winding the PMI film is specifically: pre-dipping the PMI film in viscose, and then, at room temperature, covering the surface The PMI film with the viscose is spirally wound on the carbon fiber layer.