Prepreg hot pressing method and device

Abstract

The invention relates to a prepreg hot pressing method and device, and the prepreg hot pressing method comprises the steps: laying a plurality of layers of prepregs on a compaction plane in a laminated manner, and compacting the plurality of layers of prepregs by using an auxiliary pressing plate to form a laminated plate; paving a first layer of laminated plate on the hot-pressing plane; the multiple layers of laminated plates are laid on the first layer of laminated plate layer by layer, and the multiple layers of laminated plates are subjected to circulating pressurization and pressure relief layer by layer through a pressing plate so as to exhaust interlayer gas, and a pre-laminated plate is formed; and carrying out hot pressing on the pre-laminated board to form a hot-pressed multilayer board. According to the method, the multi-layer prepreg is compacted to form the laminated plate, the multi-layer laminated plate is subjected to cyclic pressurization and pressure relief to form the pre-laminated plate, and then hot pressing is carried out, so that gas between prepreg layers is effectively discharged, the defects of bubbles and gaps in the hot-pressed multi-layer plate formed through hot pressing are reduced, the performance of the hot-pressed multi-layer plate is improved, and the product yield is increased.

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 hot-pressed multilayer boards formed by hot pressing of prepreg.

[0003] Generally, 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 the high viscosity in the molten state, it is difficult to completely discharge the interlayer gas of the multilayer prepreg, which leads to the generation of bubbles and pore defects in the hot pressed multilayer board, which has an adverse effect on 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 device.

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

[0006] Laying 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 plane;

[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 heat-pressed to form a heat-pressed multi-layer board.

[0010] In a possible implementation manner, the cyclic pressurization and decompression comprises:

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

[0012] The second preset duration of pressure relief;

[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 implementation manner, before laying the first layer of the laminate on the hot pressing plane, the prepreg hot pressing method further includes:

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

[0017] In a possible implementation manner, 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, which is used to implement the prepreg hot pressing method according to the first aspect of the present application, and the prepreg hot pressing device comprises:

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

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

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

[0024] The pressing plate is used to cyclically pressurize and release the plurality of layers of the laminated boards layer by layer to form a pre-pressed board, and to hot-press the pre-pressed board to form a hot-pressed multilayer board.

[0025] In a possible implementation manner, 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 implementation, the prepreg hot pressing device further includes:

[0028] A lifting mechanism connected to the pressing plate, the lifting mechanism being capable of driving the pressing plate to rise and fall 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 respectively 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 forms a laminate by compacting multiple layers of prepreg, cyclically pressurizing and releasing the multiple layers of laminate to form a pre-pressed laminate and then hot pressing, thereby effectively exhausting 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 may be understood through implementation of the present application. The objects and other advantages of the present application may 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 the specification and constitute a part of the specification, illustrate embodiments of the present application and are used together with the description 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, rather than all embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

[0038] Figure 4 It 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 pressure plate according to an exemplary embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme 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, rather than 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] Prepreg is an important intermediate for preparing 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 hot-pressed multilayer boards formed by hot pressing of prepreg. Prepreg can be divided into thermoplastic resin prepreg and thermosetting resin prepreg according to the different resin matrices, and can also be divided into carbon fiber prepreg, glass fiber prepreg, aramid prepreg, etc. according to the different reinforcements.

[0042] Generally, when preparing thermoplastic materials, multiple layers of prepreg need to be hot pressed to form a hot pressed multilayer board. However, the fluidity of thermoplastic resins is poor, especially high-temperature resins such as PPS (Polyphenylene sulfide) and PEEK (poly(ether-ether-ketone)). Since the resin has a high viscosity in a molten state, it is difficult for the interlayer gas of the multilayer prepreg to be completely discharged, which 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, which is then hot-pressed, 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, an 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 prepreg layers on a compaction plane, and compacting the plurality of prepreg layers using an auxiliary pressing plate to form a laminate.

[0047] Exemplarily, the ply angle of the multi-layer prepreg (not shown in the figure) is 0°, and the number of prepreg layers 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 prepreg layers 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 dead weight to facilitate compaction of the prepreg. Several spot welding holes 113 can also be set on the auxiliary pressing plate 11 to weld and fix multiple layers of prepreg through the spot welding holes 113, so as to facilitate the formation of a laminate. Exemplarily, 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 a first layer of laminate on the hot pressing plane.

[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 of moving the laminate after the prepreg is compacted to form a laminate can be reduced; when the hot pressing plane and the compacting plane are different planes, the process of compacting the prepreg and the process of pressing the laminate can be carried out simultaneously to improve 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] Step S130, laying a plurality of layers of laminated boards on the first layer of laminated board layer by layer, and using a pressing plate to cyclically pressurize and release the plurality of layers of laminated boards layer by layer to exhaust interlayer gas to form a pre-pressed board.

[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 can be understood that the embodiment of the present application does not impose any special restrictions on the number of laminates and the number of prepreg layers in each laminate, and those skilled in the art can set 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 the above pressurization and decompression process is repeated many 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 may be 200° C., and the hot pressing pressure may be greater than or equal to 1 MPa. Of course, it is understood that the specific hot pressing temperature and pressure may be set by those skilled in the art according to the type of materials actually produced, and the embodiments of the present application do not impose too many restrictions on this.

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

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

[0059] Step S132, decompression for a second preset time period.

[0060] In this step, the pressure exerted by the pressure relief finger pressure plate 21 on the laminate is 0, and the second preset time length may be the same as the first preset time length or may be different from the first preset time length. Those skilled in the art may 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, and each additional layer of laminate needs to repeat the above steps several times to ensure that the interlayer gas is completely removed. Exemplarily, when the total number of laminates is four, and each additional layer of laminate is cycled for ten times of pressurization and decompression, it is necessary to perform three paving operations on the basis of the first layer of laminate, that is, a total of thirty steps S131 and thirty steps S132 are performed, 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 decompression, and those skilled in the art can set it according to actual needs.

[0063] In some embodiments, the first preset duration ranges from 5min to 10min, and the second preset duration ranges from 5s to 10s. In one example, the first preset duration is 5min and the second preset duration is 5s. In another example, the first preset duration is 7min and the second preset duration is 8s. In yet another example, the first preset duration is 10min and the second preset duration is 10s. Of course, it is understood 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, and those skilled in the art may adjust them 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 laminated boards 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 board, 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 in the same plane, the limit frame 12 can also be used to limit the laying of the multi-layer prepreg, so as to avoid the slippage of the prepreg, and then avoid the problem of fiber bending and mechanical property deterioration after hot pressing, effectively improve the fiber alignment and mechanical properties of the hot pressed multi-layer board, and improve the product yield. Among them, 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 400mm×400mm, 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 10mm, and the size of the pressing plate 21 is 399.8mm×399.8mm×10mm. Of course, it can be 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.

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

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

[0069] Step S220, heating the hot pressing plane and the pressing plate to a first preset temperature.

[0070] Step S230, laying a first layer of laminate on the hot pressing plane.

[0071] Step S240, laying a plurality of layers of laminated boards on the first layer of laminated board layer by layer, and using a pressing plate to cyclically pressurize and release the plurality of layers of laminated boards layer by layer to exhaust interlayer gas to form a pre-pressed board.

[0072] 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 the embodiment of the present application will not be repeated here.

[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 too many restrictions on this.

[0076] Among them, heating the hot pressing plane 20 and the pressing plate 21 to the first preset temperature, and cooling the hot pressing plane 20 and the pressing plate 21 to the 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 several layers of laminate layer by layer to discharge 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 several layers of prepreg, the auxiliary pressing plate 11 is used to compact several layers of prepreg to form a laminate, the hot pressing plane 20 is used to lay the laminate, and the pressing plate 21 is used to cyclically press and release 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 supporting feet 101, the hot pressing plane 20 is arranged on the bracket 10, and multiple supporting feet 101 are arranged at the bottom of the bracket 10. Exemplarily, the number of supporting feet 101 is four, and the four supporting feet are respectively arranged at the four corners of the bottom surface of the bracket 10.

[0080] It is worth noting that the compaction 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 compaction 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 compaction 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 to improve production efficiency. It is understandable that those skilled in the art can set the hot pressing plane 20 and the compaction 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 machine compaction can be used to improve production efficiency. The embodiments of the present 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, 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, and the first connecting rod 112 is used to be held by a staff member to move the auxiliary platen 11 to be placed on the prepreg for compaction, or to be connected to a driving device (not shown in the figure) 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, a plurality of spot welding holes 113 are provided on the auxiliary pressing plate 11. 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 arranged 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 several layers of compacted prepreg to improve the tightness of the connection between the prepreg layers, so as to 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 board, which affects the performance of the finally formed hot-pressed multi-layer board.

[0086] Among them, when the compaction plane and the hot pressing plane 20 are the same plane, the limit frame 12 can also be used to limit the laying of multi-layer prepreg, so as to avoid the slippage of the prepreg, and then avoid the problem of fiber bending and mechanical property degradation after hot pressing, effectively improve the fiber alignment and mechanical properties of the hot pressed multi-layer board, and improve 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.

[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 size of the limiting frame 12 and the size of the prepreg are 400mm×400mm, 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 10mm, and the size of the pressing plate 21 is 399.8mm×399.8mm×10mm. Of course, it can be understood that the specific sizes of the limiting frame 12, the prepreg and the pressing plate 21 are not limited to the sizes 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, 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 as to achieve the pressing plate 21 to pressurize or relieve the laminate. The driving device 31 is connected to the lifting mechanism 30, and 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 another 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 is cooled to room temperature. Among them, the first preset temperature is greater than or equal to 155°C, and illustratively, the first preset temperature is 155°C; the second preset temperature is less than or equal to 20°C, and illustratively, 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 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 driving device 31 and the mold temperature controller 40 respectively to control the pressure of the pressing plate 21, the start and stop of pressurization, and the temperature, thereby realizing processes such as cyclic pressurization and pressure relief, pressure maintenance and cooling, and hot pressing.

[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 ascending button 501, a descending button 502, and a cyclic pressurization and decompression button 503. When the ascending button 501 is pressed, the control device 50 controls the driving device 31 to drive the lifting mechanism 30 to ascend relative to the hot pressing plane 20, thereby causing the pressing plate 21 to ascend; when the descending button 502 is pressed, the control device 50 controls the driving device 31 to drive the lifting mechanism 30 to descend relative to the hot pressing plane 20, thereby causing the pressing plate 21 to descend. In addition, when the cyclic pressurization and decompression button 503 is pressed, the control device 50 controls the driving device 31 to control 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 method and device for hot pressing of the embodiment of the present application is described in detail.

[0094] First, several layers of prepreg are stacked and laid on the compaction plane, and the several layers of prepreg are compacted using the auxiliary pressing plate 11 to form a laminate. The stacking and laying of prepreg on the compaction plane can be performed manually by an operator or by a laying machine, and the compacting of the prepreg to form a laminate using the auxiliary pressing plate 11 can also be performed manually or by a machine. In order to ensure that no slippage occurs when laying and compacting the prepreg, the prepreg can be laid in a limiting frame 12 and compacted.

[0095] Secondly, 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, so as 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 the embodiment of the present application does not impose too many restrictions on this.

[0097] After that, several layers of laminates are laid on the first layer of laminates layer by layer, and the press plate 21 is used to cyclically pressurize and release the several layers of laminates layer by layer to discharge the interlayer gas to form a pre-pressed laminate. Cyclic pressurization and release means that after each layer of laminates is laid, the press plate 21 presses the laminates with a preset pressure for a first preset time, then releases the pressure for a second preset time, and repeats the above steps several times.

[0098] When the pressing plate 21 is used 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 to move away from the laminate. In addition, in order to prevent the laminate from slipping, the laminate can be laid in the limit frame 12 for cyclic pressurization and decompression.

[0099] Then, the pressing plate 21 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. After the pre-pressed plate is obtained by cyclic pressurization and pressure relief, it is necessary to maintain pressure and cool the pre-pressed plate to improve the mechanical properties and facilitate subsequent operations. Among them, the driving device 31 controls the pressure of the pressing plate 21 to be maintained at 1MPa, and the mold temperature controller 40 controls the temperature of the pressing plate 21 and the hot pressing plane 20 to drop to the second preset temperature, which can be, for example, 20°C.

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

[0101] In the above embodiment, the total number of prepreg layers is sixteen, and every four prepreg layers form a laminate, and the four laminates are pressed into a pre-pressed laminate. When each additional laminate is added, it is necessary to cycle the pressure and release ten times, and finally perform hot pressing. It is understandable that the number of prepreg layers, the number of prepreg layers in each laminate, and the specific process parameters such as pressure and temperature can be set by those skilled in the art according to actual needs, and the embodiments of the present application do not impose too many restrictions on this.

[0102] In the related art, the porosity of the formed hot-pressed multilayer board is usually around 6.2%, the interlayer shear strength is around 81MPa, the fiber alignment is low, and the fibers are bent and slipped. After adopting the technical solution of the present application, the porosity of the formed hot-pressed multilayer board is reduced to around 2.3%, and the interlayer shear strength is increased to around 92MPa. At the same time, the fiber alignment is high, the fibers are straight and do not slip. This shows that the embodiments of the present application have good effects on 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.

[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 "include", "comprise" 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 statement "include..." do not exclude the existence 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 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 plane; Laying the plurality of layers of the laminated boards on the first layer of the laminated board layer by layer, 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; The pre-pressed board is heat-pressed to form a heat-pressed multi-layer board.

2. The prepreg hot pressing method according to claim 1, characterized in that: The cyclic pressurization and pressure relief comprises: After each layer of the laminate is laid, the press plate presses the laminate at a preset pressure for a first preset time period; The second preset duration of pressure relief; Repeat the above steps several times.

3. The prepreg hot pressing method according to claim 2, characterized in that: 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.

4. 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 heating and pressing plane and the pressing plate are heated to a first preset temperature.

5. The prepreg hot pressing method according to claim 4, 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.

6. The prepreg hot pressing method according to claim 5, 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.

7. A prepreg hot pressing device, characterized in that: Used to implement the prepreg hot pressing method according to any one of claims 1 to 6, the prepreg hot pressing device comprises: Compacting the plane for laying several layers of prepreg; An auxiliary pressing plate, used to compact the prepreg layers to form a laminate; A hot pressing plane for laying the laminated board; 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 a pre-pressed board, and hot-pressing the pre-pressed board to form a hot-pressed multilayer board.

8. The prepreg hot pressing device according to claim 7, characterized in that: The auxiliary pressing plate is provided with a plurality of spot welding holes, through which the compacted plurality of prepreg layers are spot welded and fixed to form the laminate.

9. The prepreg hot pressing device according to claim 7, 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.

10. The prepreg hot pressing device according to claim 7, characterized in that: The prepreg hot pressing device also includes: A lifting mechanism connected to the pressing plate, the lifting mechanism being capable of driving the pressing plate to rise and fall 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 respectively to control the pressure of the pressing plate, the start and stop of pressurization, and the temperature.

Images