Prepreg hot pressing method and device

Abstract

The present application relates to a method and device for hot pressing prepregs, and the prepreg hot pressing method includes: stacking and laying several layers of prepregs on a compacting plane, and using an auxiliary pressing plate to compact the several layers of prepregs to form a laminate; laying a first layer of laminate on the hot pressing plane; laying several layers of laminates layer by layer on the first layer of laminate, and using a pressing plate to cyclically pressurize and release the pressure on the several layers of laminate layer by layer to discharge interlayer gas to form a pre-pressed laminate; hot pressing the pre-pressed laminate to form a hot-pressed multilayer board. The present application compacts multiple layers of prepregs to form a laminate, cyclically pressurizes and releases the pressure on the multiple layers of laminate to form a pre-pressed laminate, and then hot presses, thereby effectively discharging the gas between the prepreg layers, reducing bubbles and void defects in the hot-pressed multilayer board formed by hot pressing, improving the performance of the hot-pressed multilayer board, and improving the product yield.

Description

Technical Field

[0001] The present application relates to the technical field of thermoplastic material preparation, and in particular to a prepreg hot pressing method and device. Background Art

[0002] Prepreg is an important intermediate in the preparation of thermoplastic materials. It is a combination of continuous fibers or fabrics impregnated with resin. It is also a structural unit with certain mechanical properties. The quality of prepreg will directly affect the quality of the hot-pressed multilayer board formed by hot pressing the prepreg.

[0003] Typically, when preparing thermoplastic materials, multiple layers of prepreg need to be hot-pressed to form a hot-pressed multilayer board. However, due to the poor fluidity of the resin and its high viscosity in the molten state, it is difficult to completely expel the interlayer gas of the multilayer prepreg. This leads to the generation of bubbles and pore defects in the hot-pressed multilayer board, which adversely affects the performance of the hot-pressed multilayer board. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the present application aims to provide a prepreg hot pressing method and apparatus.

[0005] According to a first aspect of the present application, a prepreg hot pressing method is provided, comprising:

[0006] Laying down a plurality of layers of prepreg on a compacting plane, and compacting the plurality of layers of prepreg using an auxiliary pressing plate to form a laminate;

[0007] Laying the first layer of the laminate on the hot pressing surface;

[0008] Laying the plurality of layers of the laminated boards layer by layer on the first layer of the laminated board, and using a pressing plate to cyclically pressurize and release the plurality of layers of the laminated boards layer by layer to discharge interlayer gas, thereby forming a pre-pressed board;

[0009] The pre-pressed board is hot-pressed to form a hot-pressed multi-layer board.

[0010] In one possible implementation, the cyclic pressurization and pressure relief includes:

[0011] After each layer of the laminate is laid, the pressing plate presses the laminate at a preset pressure for a first preset time;

[0012] Second preset time for decompression;

[0013] Repeat the above steps several times.

[0014] In a possible implementation manner, the first preset time length ranges from 5 minutes to 10 minutes, and the second preset time length ranges from 5 seconds to 10 seconds.

[0015] In a possible embodiment, before laying the first layer of the laminate on the hot pressing plane, the prepreg hot pressing method further includes:

[0016] The hot pressing plane and the pressing plate are heated to a first preset temperature.

[0017] In a possible embodiment, before hot pressing the pre-pressed board to form a hot-pressed multilayer board, the prepreg hot pressing method further includes:

[0018] The pressing plate maintains pressure and cools the pre-pressed plate at a preset pressure and a second preset temperature until the temperature of the pre-pressed plate drops to room temperature.

[0019] In a possible implementation manner, the first preset temperature is greater than or equal to 155°C, and the second preset temperature is less than or equal to 20°C.

[0020] According to a second aspect of the present application, a prepreg hot pressing device is provided for implementing the prepreg hot pressing method according to the first aspect of the present application, the prepreg hot pressing device comprising:

[0021] Compacting the surface for laying out several layers of prepreg;

[0022] An auxiliary pressing plate, used for compacting the plurality of layers of the prepreg to form a laminate;

[0023] A hot pressing plane for laying the laminated board;

[0024] The pressing plate is used for cyclically pressing and releasing the pressure on the plurality of layers of the laminated boards layer by layer to form pre-pressed boards, and hot-pressing the pre-pressed boards to form hot-pressed multi-layer boards.

[0025] In a possible implementation, the auxiliary pressing plate is provided with a plurality of spot welding holes, through which the plurality of compacted prepreg layers are spot welded and fixed to form the laminate.

[0026] In a possible embodiment, the prepreg hot pressing device also includes a limit frame, which is arranged on the hot pressing plane, and several layers of the laminates are stacked and laid in the limit frame. The pressing plate is pressed into the limit frame to cyclically pressurize and release the laminates, and the distance between the edge of the pressing plate and the limit frame is greater than or equal to 0.1 mm.

[0027] In a possible embodiment, the prepreg hot pressing device further includes:

[0028] a lifting mechanism connected to the pressing plate, wherein the lifting mechanism can drive the pressing plate to move up and down relative to the hot pressing plane;

[0029] A driving device, used for driving the lifting mechanism to move up and down;

[0030] A mold temperature controller, used to control the temperature of the hot pressing plane and the pressing plate;

[0031] The control device is electrically connected to the driving device and the mold temperature controller to control the pressure of the pressing plate, the start and stop of pressurization, and the temperature.

[0032] The advantages of the present application are as follows: the present application compacts multiple layers of prepreg to form a laminate, cyclically pressurizes and releases the multilayer laminate to form a pre-pressed laminate, and then hot presses it, thereby effectively discharging the gas between the prepreg layers, reducing the bubbles and void defects in the hot-pressed multilayer board formed by hot pressing, improving the performance of the hot-pressed multilayer board, and improving the product yield.

[0033] Other features and advantages of the present application will be set forth in the subsequent description and, in part, will become apparent from the description or understood through implementation of the present application. The purposes and other advantages of the present application can be realized and obtained through the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate embodiments of the present application and, together with the description, are used to explain the principles of the present application. In these drawings, similar reference numerals are used to identify similar elements. The drawings described below are some embodiments of the present application, but not all embodiments. For those of ordinary skill in the art, other drawings can be derived from these drawings without inventive effort.

[0035] Figure 1 FIG. 4 is a flow chart showing a prepreg hot pressing method according to an exemplary embodiment.

[0036] Figure 2 FIG. 4 is a flow chart showing a prepreg hot pressing method according to another exemplary embodiment.

[0037] Figure 3 FIG. 4 is a flow chart showing a prepreg hot pressing method according to yet another exemplary embodiment.

[0038] Figure 4 FIG1 is a schematic structural diagram of a prepreg hot pressing device according to an exemplary embodiment.

[0039] Figure 5 is a schematic structural diagram of an auxiliary pressing plate according to an exemplary embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. It should be noted that, in the absence of conflict, the embodiments in the present application and the feature vectors in the embodiments can be arbitrarily combined with each other.

[0041] Prepregs are important intermediates in the preparation of thermoplastic materials. They are a combination of continuous fibers or fabrics impregnated with resin and serve as structural units with specific mechanical properties. The quality of prepregs directly impacts the quality of the hot-pressed multilayer boards formed by hot-pressing the prepregs. Prepregs can be categorized into thermoplastic resin prepregs and thermosetting resin prepregs based on the resin matrix. They can also be categorized into carbon fiber prepregs, glass fiber prepregs, and aramid prepregs based on the reinforcement.

[0042] Typically, when preparing thermoplastic materials, multiple layers of prepreg need to be hot-pressed to form a hot-pressed multilayer board. However, thermoplastic resins have poor fluidity, especially high-temperature resins such as PPS (Polyphenylene sulfide) and PEEK (poly(ether-ether-ketone)). Since the resin has a high viscosity in the molten state, it is difficult for the interlayer gas of the multilayer prepreg to be completely discharged, which in turn leads to the generation of bubbles and pore defects in the hot-pressed multilayer board formed by hot pressing, which has an adverse effect on the performance of the hot-pressed multilayer board.

[0043] To solve the above problems, the present application provides a prepreg hot pressing method and device, which compacts multiple layers of prepreg to form a laminate, and cyclically pressurizes and releases the multi-layer laminate to form a pre-pressed laminate, and then hot presses it, thereby effectively discharging the gas between the prepreg layers, reducing the bubbles and void defects in the hot-pressed multi-layer board formed by hot pressing, improving the performance of the hot-pressed multi-layer board, and improving the product yield.

[0044] According to an exemplary embodiment, Figure 1-Figure 5 As shown, the embodiment of the present application provides a prepreg hot pressing method, which is applied to CF (Carbon Fiber) / PEEK prepreg, that is, a prepreg with a thermoplastic resin as a matrix and carbon fiber as a reinforcement. Of course, it can be understood that those skilled in the art can also apply the technical solution of the embodiment of the present application to other types of prepreg production processes according to actual production needs, and the embodiment of the present application does not impose too many restrictions on this.

[0045] The prepreg hot pressing method of the embodiment of the present application includes:

[0046] Step S110 , stacking and laying a plurality of layers of prepreg on a compaction plane, and compacting the plurality of layers of prepreg using an auxiliary pressing plate to form a laminate.

[0047] Illustratively, the ply angle of the multi-layer prepreg (not shown in the figure) is 0°, and the number of layers of the prepreg is four. Of course, it can be understood that the ply angle of the multi-layer prepreg can also be set to 45°, 90°, etc., and the number of layers of the prepreg can also be increased or decreased as needed. The embodiments of the present application do not impose any special restrictions on this, and those skilled in the art can make settings according to actual production needs.

[0048] In addition, when using the auxiliary pressing plate 11 to compact several layers of prepreg to form a laminate (not shown in the figure), manual compaction can be used to adjust the compaction direction, angle, strength and other parameters in time according to the working conditions, or a machine can be used for compaction to improve production efficiency. The auxiliary pressing plate 11 can have a certain weight to facilitate compacting the prepreg. A number of spot welding holes 113 can also be provided on the auxiliary pressing plate 11 to weld and fix the multiple layers of prepreg through the spot welding holes 113, thereby facilitating the formation of a laminate. For example, the weight of the auxiliary pressing plate 11 is 5kg to 10kg. The embodiment of the present application does not impose too many restrictions on the specific setting method of the auxiliary pressing plate 11, and those skilled in the art can make adjustments as needed.

[0049] Step S120: Laying the first layer of laminate on the hot pressing surface.

[0050] Wherein, the hot pressing plane and the compacting plane can be the same plane or different planes. When the hot pressing plane and the compacting plane are the same plane, the distance between the prepregs and the moving laminates can be reduced after compacting to form the laminates; when the hot pressing plane and the compacting plane are different planes, the process of compacting the prepregs and the pressing laminates can be carried out simultaneously, thereby improving production efficiency. Those skilled in the art can set the hot pressing plane and the compacting plane to the same plane or different planes according to actual production needs, and the embodiments of the present application do not impose too many restrictions on this.

[0051] In step S130 , several layers of laminates are laid on the first layer of laminate layer by layer, and a press plate is used to cyclically pressurize and release the several layers of laminates layer by layer to discharge interlayer gas to form a pre-pressed laminate.

[0052] For example, the number of laminates is four, and each laminate is formed by laying and compacting four layers of prepreg. That is, the pre-pressed laminate is formed by pressing a total of sixteen layers of prepreg. Of course, it is understood that the present embodiment does not impose any particular restrictions on the number of laminates or the number of prepreg layers in each laminate, and those skilled in the art can configure and adjust the production process according to actual needs.

[0053] In this step, cyclic pressurization and decompression means first pressurizing for a period of time, then decompressing for a period of time to wait for the interlayer gas to be discharged, and repeating the above pressurization and decompression process multiple times until the gas between the prepreg layers is fully discharged, so as to reduce the interlayer bubbles and pores, improve the tightness of the pre-pressed board, and thus improve the physical properties of the material.

[0054] Step S140 , hot pressing the pre-pressed board to form a hot pressed multi-layer board.

[0055] The hot pressing temperature can be 200° C., and the hot pressing pressure can be greater than or equal to 1 MPa. Of course, it is understood that the specific hot pressing temperature and pressure can be set by those skilled in the art according to the type of actual production material, and the embodiments of this application do not impose too many restrictions on this.

[0056] In some embodiments, as Figure 2 As shown, Figure 1 The cyclic pressurization and depressurization in step S130 shown in FIG includes:

[0057] Step S131 : After each layer of laminate is laid, a press plate presses the laminate at a preset pressure for a first preset time.

[0058] Illustratively, in this step, the preset pressure of the pressing plate 21 is 1 MPa, and the first preset time is 5 minutes.

[0059] Step S132: decompressing for a second preset time period.

[0060] In this step, the pressure of the pressure relief finger plate 21 on the laminate is 0, and the second preset time length can be the same as the first preset time length or different from the first preset time length. Those skilled in the art can set it according to actual production needs, and the embodiments of the present application do not impose too many restrictions on this.

[0061] Step S133, repeat the above steps several times.

[0062] Among them, the number of repetitions of step S131 and step S132 is the same. For each additional layer of laminate, the above steps need to be repeated several times to ensure that the interlayer gas is completely removed. For example, when the total number of laminates is four, when the pressurization and pressure relief are cycled ten times after each additional layer of laminate, it is necessary to perform three layings on the basis of the first layer of laminate, that is, a total of thirty steps S131 and thirty steps S132, and steps S131 and S132 are performed alternately. Of course, it is understandable that the embodiment of the present application does not impose any special restrictions on the number of cyclic pressurization and pressure relief, and those skilled in the art can set it according to actual needs.

[0063] In some embodiments, the first preset duration ranges from 5 minutes to 10 minutes, and the second preset duration ranges from 5 seconds to 10 seconds. In one example, the first preset duration is 5 minutes, and the second preset duration is 5 seconds. In another example, the first preset duration is 7 minutes, and the second preset duration is 8 seconds. In yet another example, the first preset duration is 10 minutes, and the second preset duration is 10 seconds. Of course, it is understandable that the first preset duration and the second preset duration are not limited to the above examples listed in the embodiments of the present application. Those skilled in the art can make adjustments as needed, and the embodiments of the present application do not impose too many restrictions on this.

[0064] In some embodiments, in step S130, when the pressing plate 21 is used to cyclically pressurize and release the plurality of laminates layer by layer, a limit frame 12 may also be provided. Figure 4 As shown, the limit frame 12 is set on the hot pressing plane 20, and several layers of laminates are stacked and laid in the limit frame 12. The pressing plate 21 is pressed into the limit frame 12 to cyclically pressurize and release the laminates. The limit frame 12 is used to limit the laminates to avoid slippage between the multiple laminates during the pressing process to form a pre-pressed laminate, which affects the performance of the finally formed hot-pressed multi-layer board.

[0065] It is worth noting that when the compaction plane and the hot pressing plane 20 are coplanar, the limit frame 12 can also be used to limit the placement of the multi-layer prepreg, thereby preventing the prepreg from slipping, thereby avoiding the problem of fiber bending and mechanical property degradation after hot pressing, effectively improving the fiber alignment and mechanical properties of the hot-pressed multi-layer board, and improving the product yield. The inner wall size of the limit frame 12 can be the same as the size of the prepreg, or slightly larger than the size of the prepreg, and the size of the auxiliary pressing plate 11 can be slightly smaller than the inner wall size of the limit frame 12. For example, the size of the auxiliary pressing plate 11 is the same as the size of the pressing plate 21.

[0066] In addition, in order to ensure that the pressing plate 21 can be pressed into the limiting frame 12 and to facilitate exhaust, the distance between the edge of the pressing plate 21 and the limiting frame 12 is greater than or equal to 0.1 mm, and the thickness of the pressing plate 21 is less than or equal to the thickness of the limiting frame 12. In one example, the inner wall size of the limiting frame 12 and the size of the prepreg are 400 mm × 400 mm, and the limiting frame 12 has a certain frame width and height. For example, the frame width of the limiting frame 12 and the height of the limiting frame 12 are both 10 mm, and the size of the pressing plate 21 is 399.8 mm × 399.8 mm × 10 mm. Of course, it is understandable that the specific dimensions of the limiting frame 12, the prepreg and the pressing plate 21 are not limited to the dimensions listed in the embodiments of the present application, and those skilled in the art can set them according to actual needs.

[0067] In some embodiments, as Figure 3 As shown, the prepreg hot pressing method includes:

[0068] Step S210 , stacking and laying a plurality of layers of prepreg on a compaction plane, and compacting the plurality of layers of prepreg using an auxiliary pressing plate to form a laminate.

[0069] In step S220 , the temperature of the hot pressing surface and the pressing plate is raised to a first preset temperature.

[0070] Step S230: Laying the first layer of laminate on the hot pressing plane.

[0071] In step S240 , several layers of laminates are laid on the first layer of laminate layer by layer, and a pressing plate is used to cyclically pressurize and release the several layers of laminates layer by layer to discharge interlayer gas to form a pre-pressed laminate.

[0072] In step S250 , the pressing plate maintains pressure and cools the pre-pressed plate at a preset pressure and a second preset temperature until the temperature of the pre-pressed plate drops to room temperature.

[0073] Step S260 , hot pressing the pre-pressed board to form a hot pressed multi-layer board.

[0074] Among them, step S210, step S230, step S240 and step S260 are the same as step S110 to step S140 described in the above embodiment, and are not repeated here in the embodiment of the present application.

[0075] In step S220, the first preset temperature is greater than or equal to 155° C., and illustratively, the first preset temperature is 155° C. In step S250, the second preset temperature is less than or equal to 20° C., and illustratively, the second preset temperature is 20° C. Of course, it is understood that the specific values ​​of the first preset temperature and the second preset temperature can be set by those skilled in the art in combination with production conditions and according to actual needs, and the embodiments of the present application do not impose excessive restrictions on this.

[0076] Among them, heating the hot pressing plane 20 and the pressing plate 21 to a first preset temperature, and cooling the hot pressing plane 20 and the pressing plate 21 to a second preset temperature can be achieved by the mold temperature controller 40. Controlling the pressurization and depressurization of the pressing plate 21 and the pressure size can be achieved by setting a lifting mechanism 30 connected to the pressing plate 21, and a driving device 31 connected to the lifting mechanism 30. This will be described in detail in the subsequent embodiments of this application and will not be repeated here.

[0077] According to an exemplary embodiment, Figure 1-Figure 5As shown, an embodiment of the present application provides a prepreg hot pressing device for implementing the prepreg hot pressing method as described in the above embodiment. The prepreg hot pressing method includes: S110, stacking and laying several layers of prepreg on a compaction plane (not shown in the figure), and using an auxiliary pressing plate 11 to compact the several layers of prepreg to form a laminate (not shown in the figure); S120, laying a first layer of laminate on the hot pressing plane 20; S130, laying several layers of laminate on the first layer of laminate layer by layer, and using a pressing plate 21 to cyclically pressurize and release the several layers of laminate layer by layer to discharge the interlayer gas to form a pre-pressed laminate (not shown in the figure); S140, hot pressing the pre-pressed laminate to form a hot-pressed multilayer board (not shown in the figure).

[0078] like Figure 4-Figure 5 As shown, the prepreg hot pressing device includes a compacting plane, an auxiliary pressing plate 11, a hot pressing plane 20, and a pressing plate 21. The compacting plane is used to stack and lay out several layers of prepreg, the auxiliary pressing plate 11 is used to compact the several layers of prepreg to form a laminate, the hot pressing plane 20 is used to lay out the laminate, and the pressing plate 21 is used to cyclically pressurize and release the several layers of laminate layer by layer to form a pre-pressed laminate, and to hot press the pre-pressed laminate to form a hot-pressed multilayer board.

[0079] In some embodiments, the prepreg hot pressing device also includes a bracket 10 and support legs 101, the hot pressing plane 20 is set on the bracket 10, and multiple support legs 101 are set at the bottom of the bracket 10. Exemplarily, the number of support legs 101 is four, and the four support legs are respectively set at the four corners of the bottom surface of the bracket 10.

[0080] It is worth noting that the compacting plane can be the same plane as the hot pressing plane 20, or it can be a different plane. When the hot pressing plane 20 and the compacting plane are the same plane, the process of compacting the prepreg to form a laminate, and the process of pressing the laminate to form a pre-pressed plate are all operated on the same plane, which can reduce the distance of the mobile laminate. When the hot pressing plane 20 and the compacting plane are different planes, the process of compacting the prepreg to form a laminate, and the process of pressing the laminate to form a pre-pressed plate can be carried out simultaneously, thereby improving production efficiency. It is understandable that those skilled in the art can set the hot pressing plane 20 and the compacting plane to the same plane or different planes according to actual production needs, and the embodiments of the present application do not impose too many restrictions on this.

[0081] Among them, manual compaction can be used to adjust the compaction direction, angle, strength and other parameters in time according to the working conditions, or machines can be used for compaction to improve production efficiency. The embodiments of this application do not impose any special restrictions on this, and technical personnel in this field can make settings according to actual needs.

[0082] In some embodiments, the auxiliary platen 11 includes a first body 111 and a first connecting rod 112. The first surface of the first body 111 is used to contact the prepreg, and the second surface of the first body 111 is connected to the first connecting rod 112. The first surface and the second surface are different surfaces of the first body 111. The first connecting rod 112 is used to be grasped by a worker to move the auxiliary platen 11 to be placed on the prepreg for compaction, or to be connected to a driving device (not shown) for compaction.

[0083] In some embodiments, the auxiliary pressing plate 11 may have a certain weight to facilitate compacting the prepreg. Exemplarily, the weight of the auxiliary pressing plate 11 is 5 kg to 10 kg.

[0084] In some embodiments, the auxiliary pressing plate 11 is provided with a plurality of spot welding holes 113. Figure 5 As shown, in the embodiment of the present application, the number of spot welding holes 113 is eight, and the eight spot welding holes 113 are provided on the first body 111 and are evenly arranged around the connection position between the first body 111 and the first connecting rod 112. The spot welding holes 113 can be used to spot weld and fix the compacted layers of prepreg to improve the tightness of the connection between the prepreg layers and facilitate the formation of a laminate. Of course, it is understandable that the number of spot welding holes 113 can be increased or decreased by those skilled in the art according to actual needs, and the arrangement of the spot welding holes 113 can also be adjusted as needed, such as array arrangement, uneven arrangement, etc., and the embodiment of the present application does not impose too many restrictions on this.

[0085] In some embodiments, the prepreg hot pressing device further includes a limit frame 12. Figure 4 As shown, the limit frame 12 is set on the hot pressing plane 20, and several layers of laminates are stacked and laid in the limit frame 12. The pressing plate 21 is pressed into the limit frame 12 to cyclically pressurize and release the laminates. The limit frame 12 is used to limit the laminates to avoid slippage between the multiple laminates during the pressing process to form a pre-pressed laminate, which affects the performance of the finally formed hot-pressed multi-layer board.

[0086] When the compaction plane and the hot pressing plane 20 are coplanar, the limit frame 12 can also be used to limit the placement of the multilayer prepreg, thereby preventing the prepreg from slipping, thereby avoiding fiber bending and mechanical property degradation after hot pressing, effectively improving the fiber alignment and mechanical properties of the hot-pressed multilayer board, and improving product yield. The inner wall dimensions of the limit frame 12 can be the same as the dimensions of the prepreg, or slightly larger than the dimensions of the prepreg. The dimensions of the auxiliary pressing plate 11 can be slightly smaller than the inner wall dimensions of the limit frame 12. For example, the dimensions of the auxiliary pressing plate 11 are the same as the dimensions of the pressing plate 21.

[0087] In addition, in order to ensure that the pressing plate 21 can be pressed into the limiting frame 12 and facilitate exhaust, the distance between the edge of the pressing plate 21 and the limiting frame 12 is greater than or equal to 0.1 mm, and the thickness of the pressing plate 21 is less than or equal to the thickness of the limiting frame 12.

[0088] In one example, the inner wall dimensions of the limiting frame 12 and the dimensions of the prepreg are 400 mm × 400 mm, the limiting frame 12 has a certain frame width and height, for example, the frame width and height of the limiting frame 12 are both 10 mm, and the dimensions of the pressing plate 21 are 399.8 mm × 399.8 mm × 10 mm. Of course, it is understood that the specific dimensions of the limiting frame 12, the prepreg, and the pressing plate 21 are not limited to the dimensions listed in the embodiments of the present application, and those skilled in the art can set them according to actual needs.

[0089] In some embodiments, as Figure 4 As shown, the prepreg hot pressing device also includes a lifting mechanism 30, a driving device 31, a mold temperature controller 40 and a control device 50. Among them, the lifting mechanism 30 is connected to the pressing plate 21, and the prepreg hot pressing device can be provided with a guide rail 102 along the vertical direction. The lifting mechanism 30 can move along the guide rail 102, thereby driving the pressing plate 21 to rise and fall relative to the hot pressing plane 20, so that the pressing plate 21 can pressurize or relieve pressure on the laminate. The driving device 31 is connected to the lifting mechanism 30. The driving device 31 can, for example, include a motor for driving the lifting mechanism 30 to rise and fall, so that the lifting mechanism drives the pressing plate 21 to rise and fall relative to the hot pressing plane 20. In addition, the driving device 31 can also include a hydraulic press for pressurizing the pressing plate 21.

[0090] The mold temperature controller 40 is connected to the hot pressing plane 20 and the pressing plate 21 respectively, and is used to control the temperature of the hot pressing plane 20 and the pressing plate 21, for example, heating the hot pressing plane 20 and the pressing plate 21 to a first preset temperature, so that the pressing plate 21 is used to cyclically pressurize and release the pressure of several layers of laminates layer by layer to discharge the interlayer gas to form a pre-pressed plate, and for example, cooling the hot pressing plane 20 and the pressing plate 21 to a second preset temperature, so as to maintain the pressure and cool the pre-pressed plate formed by pressing until the pre-pressed plate cools to room temperature. Among them, the first preset temperature is greater than or equal to 155°C, and for example, the first preset temperature is 155°C; the second preset temperature is less than or equal to 20°C, and for example, the second preset temperature is 20°C. Of course, it can be understood that the specific values ​​of the first preset temperature and the second preset temperature can be set by those skilled in the art in combination with the production situation and according to actual needs, and the embodiments of the present application do not impose too many restrictions on this.

[0091] In some embodiments, the control device 50 is electrically connected to the drive device 31 and the mold temperature controller 40 respectively to control the pressure of the pressure plate 21, the start and stop of pressurization, and the temperature, thereby realizing cyclic pressurization and pressure relief, pressure maintenance and cooling, and hot pressing processes.

[0092] In some embodiments, the control device 50 is provided with a plurality of control buttons. Figure 4 As shown, the control device 50 includes an up button 501, a down button 502, and a cyclic pressurization and decompression button 503. When the up button 501 is pressed, the control device 50 controls the drive device 31, driving the lifting mechanism 30 to rise relative to the hot pressing plane 20, thereby raising the pressing plate 21. When the down button 502 is pressed, the control device 50 controls the drive device 31, driving the lifting mechanism 30 to descend relative to the hot pressing plane 20, thereby lowering the pressing plate 21. In addition, when the cyclic pressurization and decompression button 503 is pressed, the control device 50 controls the drive device 31, thereby controlling the pressing plate 21 to perform cyclic pressurization and decompression.

[0093] According to an exemplary embodiment, the present application embodiment will be combined with Figure 1-Figure 5 As shown, the process of hot pressing the prepreg using the hot pressing method and device of the embodiment of the present application is described in detail.

[0094] First, several layers of prepreg are stacked and laid on a compaction plane, and then compacted using auxiliary pressing plates 11 to form a laminate. Stacking and laying the prepregs on the compaction plane can be done manually by an operator or using a laying machine. Compacting the prepregs to form a laminate using auxiliary pressing plates 11 can also be done manually or by machine. To prevent slippage during laying and compacting of the prepregs, the prepregs can be laid and compacted within a limiting frame 12.

[0095] Next, the hot pressing plane 20 and the pressing plate 21 are heated to a first preset temperature. The mold temperature controller 40 heats the hot pressing plane 20 and the pressing plate 21 to a first preset temperature greater than or equal to 155°C. For example, the first preset temperature is 155°C.

[0096] Subsequently, the first layer of laminate is laid on the hot pressing plane 20. At this time, the control device 50 controls the lifting mechanism 30 to rise through the driving device 31, and the lifting mechanism drives the pressing plate 21 to rise to facilitate laying. When laying the laminate on the hot pressing plane 20, it can be done manually by an operator or by a machine, and this embodiment of the application does not impose too many restrictions on this.

[0097] Afterwards, several layers of laminates are layered onto the first layer of laminates, and the press plate 21 is used to cyclically pressurize and release the layers to expel interlayer air, forming pre-pressurized laminates. Cyclic pressurization and release means that after each layer of laminates is laid, the press plate 21 presses the laminates at a preset pressure for a first preset time, then releases the pressure for a second preset time, and repeats this process several times.

[0098] When using the pressing plate 21 for cyclic pressurization and decompression, the driving device 31 controls the lifting mechanism 30 to descend, thereby driving the pressing plate 21 to descend to pressurize the laminate. During the cyclic pressurization and decompression process, the driving device 31 can adjust the pressure of the pressing plate 21. When decompressing, the pressure of the pressing plate 21 can be controlled to 0, or the pressing plate 21 can be driven to rise away from the laminate. In addition, to prevent the laminate from slipping, the laminate can be laid within the limit frame 12 for cyclic pressurization and decompression.

[0099] The press plate 21 then maintains pressure and cools the pre-pressed sheet at a preset pressure and a second preset temperature until the temperature of the pre-pressed sheet drops to room temperature. After the pre-pressed sheet is obtained through cyclic pressurization and decompression, it is necessary to maintain pressure and cool the pre-pressed sheet to improve its mechanical properties and facilitate subsequent operations. The drive device 31 controls the pressure of the press plate 21 to remain at 1 MPa, and the mold temperature controller 40 controls the temperature of the press plate 21 and the hot pressing surface 20 to drop to the second preset temperature, which can be, for example, 20°C.

[0100] Finally, the pre-pressed sheet is hot-pressed to form a hot-pressed multilayer sheet. In this step, the pre-pressed sheet can be placed in a mold for hot pressing. During hot pressing, the driving device 31 controls the lifting mechanism 30 to descend, thereby driving the pressing plate 21 to descend. The mold temperature controller 40 controls the temperature of the pressing plate 21 and the hot pressing surface 20 to achieve hot pressing.

[0101] In the above embodiment, the total number of prepreg layers is sixteen, with four prepreg layers forming a laminate, and four laminate layers pressed together to form a pre-pressed laminate. Each additional laminate layer requires ten cycles of pressurization and depressurization, followed by a final hot press. It will be appreciated that the number of prepreg layers, the number of prepreg layers per laminate, and specific process parameters such as pressure and temperature can be set by those skilled in the art based on actual needs, and the present embodiment does not impose any particular limitations thereon.

[0102] In related technologies, the porosity of the hot-pressed multilayer board formed is usually around 6.2%, the interlayer shear strength is around 81 MPa, the fiber alignment is low, and the fibers are subject to bending and slippage. However, after adopting the technical solution of the present application, the porosity of the hot-pressed multilayer board formed is reduced to around 2.3%, and the interlayer shear strength is increased to around 92 MPa. At the same time, the fiber alignment is high, the fibers are straight, and there is no slippage. This shows that the embodiments of the present application have a good effect in venting gas between prepreg layers, reducing bubbles and void defects in the hot-pressed multilayer board formed by hot pressing, improving the performance of the hot-pressed multilayer board, and improving product yield.

[0103] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprising..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, rather than to limit it. The present application is described in detail with reference to the preferred embodiments only. Those skilled in the art should understand that the technical solution of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application, and should be included in the scope of the claims of the present application.

Claims

1. A prepreg hot pressing method, characterized in that: include: Laying down a plurality of layers of prepreg on a compacting plane, and compacting the plurality of layers of prepreg using an auxiliary pressing plate to form a laminate; Laying the first layer of the laminate on the hot pressing surface; Laying the plurality of layers of the laminated boards layer by layer on the first layer of the laminated board, and using a pressing plate to cyclically pressurize and release the plurality of layers of the laminated boards layer by layer to discharge interlayer gas, thereby forming a pre-pressed board; Hot pressing the pre-pressed board to form a hot-pressed multi-layer board; The cyclic pressurization and pressure relief comprises: After each layer of the laminate is laid, the pressing plate presses the laminate at a preset pressure for a first preset time; Second preset time for decompression; Repeat the above steps several times; The prepreg hot pressing method is implemented by a prepreg hot pressing device, which includes the compacting plane, the auxiliary pressing plate, the hot pressing plane and the pressing plate, and the auxiliary pressing plate is provided with a plurality of spot welding holes, through which the compacted plurality of prepreg layers are spot welded to form the laminate. The first preset time length ranges from 5 minutes to 10 minutes, and the second preset time length ranges from 5 seconds to 10 seconds.

2. The prepreg hot pressing method according to claim 1, characterized in that: Before laying the first layer of the laminate on the hot pressing plane, the prepreg hot pressing method further comprises: The hot pressing plane and the pressing plate are heated to a first preset temperature.

3. The prepreg hot pressing method according to claim 2, characterized in that: Before hot pressing the pre-pressed board to form a hot-pressed multilayer board, the prepreg hot pressing method further comprises: The pressing plate maintains pressure and cools the pre-pressed plate at a preset pressure and a second preset temperature until the temperature of the pre-pressed plate drops to room temperature.

4. The prepreg hot pressing method according to claim 3, characterized in that: The first preset temperature is greater than or equal to 155° C., and the second preset temperature is less than or equal to 20° C.

5. The prepreg hot pressing method according to claim 1, characterized in that: The prepreg hot pressing device also includes a limit frame, which is arranged on the compaction plane. Several layers of the laminates are stacked and laid in the limit frame. The pressing plate is pressed into the limit frame to cyclically pressurize and release the laminates. The distance between the edge of the pressing plate and the limit frame is greater than or equal to 0.1 mm.

6. The prepreg hot pressing method according to claim 1, characterized in that: The prepreg hot pressing device also includes: a lifting mechanism connected to the pressing plate, wherein the lifting mechanism can drive the pressing plate to move up and down relative to the hot pressing plane; A driving device, used for driving the lifting mechanism to move up and down; A mold temperature controller, used to control the temperature of the hot pressing plane and the pressing plate; The control device is electrically connected to the driving device and the mold temperature controller to control the pressure of the pressing plate, the start and stop of pressurization, and the temperature.

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