Multi-axial fiber prepreg as well as preparation method and production equipment thereof

Abstract

The invention belongs to the technical field of carbon fiber composite materials, and particularly relates to a multi-axial fiber prepreg as well as a preparation method and production equipment thereof. The preparation method comprises the following steps: taking a layer of unidirectional fiber prepreg produced on line as a base layer, and sequentially laying N layers of unidirectional fiber prepreg on the base layer to obtain the multiaxial fiber prepreg, in the laying process, the unidirectional fiber prepregs on the same layer are in the same direction and are continuous; and the direction of at least one layer in the N layers of laid unidirectional fiber prepregs is different from the direction of the base layer. According to the multi-axial fiber prepreg disclosed by the invention, fibers in different layers are free from interlacing points, the fiber strength conversion rate is high, and the mechanical property is excellent; the multi-axial fiber prepreg is prepared on line in the prepreg production process, the fiber angles of different laying layers are adjustable, the coiled prepreg can be directly prepared, and subsequent secondary processing is not needed.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon fiber composite materials, in particular to a multi-axial fiber prepreg and a preparation method and production equipment thereof. Background Art

[0002] Fiber reinforced resin-based composite materials are currently widely used in various fields such as aerospace, rail transportation, sports equipment, etc. The current fiber composite material market has been developing steadily and rapidly, and fiber prepreg is an important raw material for making fiber reinforced resin-based composite materials.

[0003] Fiber prepregs are divided into fabric prepregs and unidirectional prepregs. Carbon fiber unidirectional prepregs have a higher strength conversion rate because their reinforcing fibers are continuous and there are no interlacing points between fiber bundles. However, unidirectional carbon fiber prepregs have lower mechanical properties in the width direction because they have no yarns in the width direction. Fabric prepregs include bidirectional fabric prepregs (plain, twill, satin) and multi-axial warp knitted fabric prepregs. The bidirectional fabric prepregs have low fiber strength conversion rate due to the interweaving points between radial fibers and weft fibers, and the warp and weft fibers are not arranged straight in the prepreg. Multi-axial warp knitted fabric prepregs are prepared by impregnating multi-axial warp knitted fabrics with thermosetting resin. There are no interweaving points between the main carbon fibers, and the fiber strength conversion rate is high. At the same time, multi-axial warp knitted fabrics can be multiple fiber layers in different directions. The prepared prepregs have high mechanical properties such as warp and weft strength and modulus. However, the production efficiency of carbon fiber fabrics is low. The output of bidirectional fabrics on a single machine in the industry is ≤300m / day, and the output of multi-axial warp knitted fabrics is ≤800m / day. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention provides a multi-axial fiber prepreg and a preparation method and production equipment thereof, which can improve the strength of the fiber prepreg and prepare the multi-axial fiber prepreg online.

[0005] To achieve the above object, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, the present application provides a method for preparing a multi-axial fiber prepreg, comprising the following steps:

[0007] Using a layer of unidirectional fiber prepreg produced online as a base layer, and sequentially laying N layers of unidirectional fiber prepreg thereon to obtain the multi-axial fiber prepreg;

[0008] During the laying process, the unidirectional fiber prepregs in the same layer are in the same direction and continuous;

[0009] Wherein N≥1, the direction of at least one layer among the N layers of unidirectional fiber prepreg laid is different from the direction of the base layer.

[0010] Optionally, the method of laying the next layer of unidirectional fiber prepreg to be laid on the base layer with <N layers of unidirectional fiber prepreg laid as the base layer comprises the following steps:

[0011] S1: After adjusting the angle of the unidirectional fiber prepreg of the layer to be laid, the unidirectional fiber prepreg is conveyed to the base layer, until the front end of the unidirectional fiber prepreg of the layer to be laid overlaps with one side of the base layer, the unidirectional fiber prepreg of the layer to be laid is cut along the other side of the base layer to form a laying section, the base layer moves forward, and the laying section is compacted by a compaction roller;

[0012] S2: the base layer continues to move forward, and during the moving process, the unidirectional fiber prepreg of the layer to be laid is again conveyed to the base layer, until the front end of the unidirectional fiber prepreg of the layer to be laid overlaps with one side of the base layer, the unidirectional fiber prepreg of the layer to be laid is again cut along the other side of the base layer to form a new laying section, and then the new laying section is compacted by a compaction roller; the laying sections are connected at the ends;

[0013] S3: Continue the operation in S2 until the unidirectional fiber prepreg to be laid forms a continuous and full laying layer on the base layer.

[0014] Optionally, the directions of the N layers of unidirectional fiber prepreg laid are the same or different.

[0015] Optionally, the angle between the length direction of the laid N layers of unidirectional fiber prepreg and the length direction of the base layer is -90° to 90°.

[0016] Optionally, the angle between the length direction of the laid N layers of unidirectional fiber prepreg and the length direction of the base layer is -60° to -30° or 30° to 60°.

[0017] Optionally, the unidirectional fiber prepreg comprises an upper glue film, a lower glue film and a fiber reinforcement material impregnated between the upper glue film and the lower glue film.

[0018] Optionally, the fiber reinforcement material is organic fiber or inorganic fiber.

[0019] Optionally, the reinforcing material is one or more of polyacrylonitrile-based, asphalt-based, viscose-based carbon fiber, glass fiber and basalt fiber.

[0020] Optionally, the temperature of the compacting roller is 30-40°C.

[0021] Optionally, the unidirectional fiber prepreg has a fiber surface density of 20-300 g / m 2 .

[0022] In a second aspect, the present application also provides a multi-axial fiber prepreg, which is prepared by the method described in the first aspect.

[0023] In the third aspect, the present application also provides a production equipment for the multi-axial fiber prepreg described in the second aspect, comprising a traction roller, a winding roller and a laying assembly, wherein the traction roller is connected to the winding roller, and the laying assembly is provided with N groups, and the N groups of laying assemblies are arranged in sequence between the traction roller and the winding roller; the laying assembly comprises a unwinding device for the unidirectional fiber prepreg to be laid layer, a movable track, a guide assembly, a compacting roller and a cutting assembly, the discharge end of the unwinding device for the unidirectional fiber prepreg to be laid layer is connected to the movable track, and the movable track is used to adjust the direction of the unidirectional fiber prepreg to be laid layer, and the movable track is connected to the discharge end of the traction roller through the guide assembly, the cutting assembly is used to cut the unidirectional fiber prepreg to be laid layer, and the compacting roller is used to compact the unidirectional fiber prepreg to be laid layer with the base layer.

[0024] Optionally, the traction roller is arranged at the discharge end of the base production line.

[0025] Compared with the prior art, this application has at least the following beneficial effects:

[0026] There are no interlacing points between fibers of different layers in the multi-axial fiber prepreg of the present invention, and the fiber strength conversion rate is high; the preparation method and production device of the present invention can prepare multi-axial fiber prepreg online during the prepreg production process, the fiber angles of different laying layers are adjustable, and roll prepreg can be directly prepared without subsequent secondary processing; and during the online production process of the base layer prepreg, prepregs of different angles are laid on it, and the length of the finished multi-axial prepreg can be adjusted as needed, and the length is not limited. The resin content of the multi-axial fiber prepreg prepared by the present invention is controllable, and the obtained multi-axial fiber prepreg has excellent mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a multi-axial fiber prepreg production device in the present application embodiment;

[0028] Figure 2 for Figure 1 A top view of

[0029] Description of reference numerals:

[0030] 1. Second traction roller; 2. Fiber unwinding device; 3. Laying assembly; 31. Unwinding device for unidirectional fiber prepreg to be laid layer; 32. Movable track; 33. Guide assembly; 34. Compacting roller; 35. Cutting assembly; 4. Traction roller; 5. Cooling plate; 6. Second impregnation roller; 7. Heating plate; 8. First impregnation roller; 9. Winding roller. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0032] The experimental methods used in the embodiments of the present invention are conventional methods unless otherwise specified.

[0033] The reagents and materials used in this example can all be purchased conventionally. The quantitative experiments involved in the examples were repeated at least three times, and the results were averaged.

[0034] Example

[0035] like Figure 1 and Figure 2 As shown, a production equipment for multi-axial fiber prepreg includes a traction roller 4, a winding roller 9 and a laying component 3. The unidirectional fiber prepreg of the base layer produced online moves from the traction roller 4 to the winding roller 9. The laying component 3 is provided with a group, and the laying component 3 is arranged between the traction roller 4 and the winding roller 9; the laying component 3 includes a unidirectional fiber prepreg unwinding device 31 for the layer to be laid, a movable track 32, a guide component 33, a compacting roller 34 and a cutting component 35. The discharge end of the unidirectional fiber prepreg unwinding device 31 for the layer to be laid is connected to the movable track 32, the movable track 32 is used to adjust the direction of the unidirectional fiber prepreg of the layer to be laid, the movable track 32 is connected to the discharge end of the traction roller 1 through the guide component 33, the cutting component 35 is used to cut the unidirectional fiber prepreg of the layer to be laid, and the compacting roller 34 is used to compact the unidirectional fiber prepreg of the layer to be laid with the base layer.

[0036] It also includes a fiber unwinding device 2 and a film unwinding device. The discharge ends of the fiber unwinding device 2 and the film unwinding device are connected to the traction roller 4 through the first impregnation roller 8, the heating plate 7, three groups of second impregnation rollers 6 and the cooling plate 5 in sequence. The laying component 3 is arranged at the discharge end of the traction roller 4, and the base layer is led out through online production.

[0037] A method for preparing a multi-axial fiber prepreg is carried out using the above device, and the steps are as follows:

[0038] A layer of unidirectional fiber prepreg produced online is used as a base layer, and N layers of unidirectional fiber prepreg are laid thereon in sequence to obtain the multi-axial fiber prepreg; N can be selected according to needs, and in this embodiment, N is 1. The unidirectional fiber prepreg of the base layer and the laid unidirectional fiber prepreg can be made of the same material or different materials. In this embodiment, the same material is selected; the angle between the laid unidirectional fiber prepreg and the base layer can also be set according to needs;

[0039] S0: First, the upper glue film and the lower glue film are drawn out from the glue film unwinding device, and are respectively compounded with the upper and lower surfaces of the reinforcing material unwinding from the fiber unwinding device, and then pass through the first impregnation roller 8, and the upper and lower glue films are melted and impregnated into the fiber reinforcement material by the temperature and pressure of the first impregnation roller, and then pass through the heating plate 7, three groups of second impregnation rollers 6, and then are cooled by the first cooling plate 5 to obtain the base layer;

[0040] S1: The base layer moves forward under the action of the traction roller 4; after the unidirectional fiber prepreg of the layer to be laid is unwound by the unidirectional fiber prepreg unwinding device 31, the angle of the unidirectional fiber prepreg of the layer to be laid is adjusted by the movable track 32, and after being guided by the guide component 33, it is transported to the base layer (i.e., the base layer, at this time, the unidirectional fiber prepreg of the 0th layer is laid), until the front end of the unidirectional fiber prepreg of the layer to be laid coincides with one side of the base layer, the unidirectional fiber prepreg of the layer to be laid is cut along the other side of the base layer by operating the cutting component 35 to form a laying section, the base layer moves forward, and the laying section is compacted by the compacting roller 34; the temperature of the compacting roller 34 is set to 30°C;

[0041] S2: the base layer moves forward under the action of the second traction roller, and the unidirectional fiber prepreg of the layer to be laid is further conveyed to the base layer during the forward movement process, and after the front end of the unidirectional fiber prepreg of the layer to be laid overlaps with one side of the base layer, the unidirectional fiber prepreg of the layer to be laid is cut off along the other side of the base layer again to form a new laying section, and then the new laying section is compacted by a compaction roller; the laying sections are connected at the ends;

[0042] S3: Continue the operation in S2 until the unidirectional fiber prepreg to be laid forms a continuous and full laying layer on the base layer to obtain the multi-axial fiber prepreg;

[0043] The unidirectional fiber prepregs in the same layer are in the same direction.

[0044] In this embodiment, the angle between the unidirectional fiber prepreg of the to-be-laid layer and the unidirectional fiber prepreg of the base layer in the length direction is 45°.

[0045] Among them, the production speed is 5m / min, winding.

[0046] In this embodiment, the unidirectional fiber prepreg for laying layer includes an upper film, a lower film and a fiber reinforcement material impregnated between the upper film and the lower film. The preparation method is the same as that of the base layer. The fiber reinforcement material uses Hengshen HF40F-12K fiber, and the film uses Hengshen's high-temperature curing epoxy resin; the resin content in the unidirectional fiber prepreg is 35%, and the fiber surface density is 200g / m 2 Among them, the width of the base layer unidirectional fiber prepreg is 1000mm, and the width of the unidirectional fiber prepreg of the layer to be laid is 300mm.

[0047] The preparation method and production device of the present invention can prepare multi-axial fiber prepreg online during the prepreg production process, the fiber angles of different laying layers can be adjusted, and the rolled prepreg can be directly prepared without subsequent secondary processing. The resin content of the multi-axial fiber prepreg prepared by the present invention is controllable, the mechanical properties of the obtained multi-axial fiber prepreg are excellent, and the production capacity is also greatly improved.

Claims

1. A method for preparing a multi-axial fiber prepreg, characterized in that: The steps include: Using a layer of unidirectional fiber prepreg produced online as a base layer, and sequentially laying N layers of unidirectional fiber prepreg thereon to obtain the multi-axial fiber prepreg; During the laying process, the unidirectional fiber prepregs in the same layer are in the same direction and continuous; Wherein N≥1, the direction of at least one layer among the N layers of unidirectional fiber prepreg laid is different from the direction of the base layer.

2. The method for preparing a multi-axial fiber prepreg according to claim 1, characterized in that: The method of laying the next layer of unidirectional fiber prepreg to be laid on the base layer with less than N layers of unidirectional fiber prepreg laid as the base layer comprises the following steps: S1: After adjusting the angle of the unidirectional fiber prepreg of the layer to be laid, the unidirectional fiber prepreg is conveyed to the base layer, until the front end of the unidirectional fiber prepreg of the layer to be laid overlaps with one side of the base layer, the unidirectional fiber prepreg of the layer to be laid is cut along the other side of the base layer to form a laying section, the base layer moves forward, and the laying section is compacted by a pressing roller; S2: the base layer continues to move forward, and during the moving process, the unidirectional fiber prepreg of the layer to be laid is again conveyed to the base layer, until the front end of the unidirectional fiber prepreg of the layer to be laid overlaps with one side of the base layer, the unidirectional fiber prepreg of the layer to be laid is again cut along the other side of the base layer to form a new laying section, and then the new laying section is compacted by a pressing roller; the laying sections are connected at the ends; S3: Continue the operation in S2 until the unidirectional fiber prepreg to be laid forms a continuous and full laying layer on the base layer.

3. The method for preparing a multi-axial fiber prepreg according to claim 1, characterized in that: The directions of the N layers of unidirectional fiber prepreg laid are the same or different.

4. The method for preparing a multi-axial fiber prepreg according to claim 1, characterized in that: The angle between the length direction of the laid N layers of unidirectional fiber prepreg and the length direction of the base layer is -90° to 90°.

5. The method for preparing a multi-axial fiber prepreg according to claim 1, characterized in that: The unidirectional fiber prepreg comprises an upper glue film, a lower glue film and a fiber reinforcement material impregnated between the upper glue film and the lower glue film.

6. The method for preparing a multi-axial fiber prepreg according to claim 2, characterized in that: The temperature of the compacting roller is 30-40°C.

7. The method for preparing a multi-axial fiber prepreg according to claim 1, characterized in that: The unidirectional fiber prepreg fiber surface density is 20-300g / m 2 .

8. A multi-axial fiber prepreg, characterized in that: The method is prepared by any one of claims 1 to 7.

9. A production device for the multi-axial fiber prepreg according to claim 8, characterized in that: It includes a traction roller, a winding roller and a laying component, the traction roller is connected to the winding roller, the laying component is provided with N groups, and the N groups of laying components are arranged in sequence between the traction roller and the winding roller; the laying component includes a unidirectional fiber prepreg unwinding device for the layer to be laid, a movable track, a guide component, a compacting roller and a cutting component, the discharge end of the unidirectional fiber prepreg unwinding device for the layer to be laid is connected to the movable track, the movable track is used to adjust the direction of the unidirectional fiber prepreg for the layer to be laid, the movable track is connected to the discharge end of the traction roller through the guide component, the cutting component is used to cut the unidirectional fiber prepreg for the layer to be laid, and the compacting roller is used to compact the unidirectional fiber prepreg for the layer to be laid with the base layer.

10. The production equipment of multi-axial fiber prepreg according to claim 9, characterized in that: The traction roller is arranged at the discharge end of the base production line.

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