Resin filling device for improving resin fluidity through electric assistance and application of resin filling device

Abstract

The invention belongs to the field of fiber reinforced resin matrix composite material forming processes, and particularly relates to a resin filling device for improving resin fluidity through electric assistance and application of the resin filling device. A resin filling device for improving resin fluidity through electric assistance is characterized by specifically comprising a filling component, a resin inlet and a resin outlet; the pouring component sequentially comprises a mold, a lower electrode plate, a dielectric layer, a fiber preform, demolding cloth, an upper electrode plate and a packaging bag from bottom to top; the two ends of the demolding cloth respectively extend downwards to be in contact with a mold; the periphery of the packaging bag extends downwards to be fixedly connected with the mold. The resin inlet and the resin outlet are respectively positioned above the two ends of the extending demolding cloth; the upper electrode plate and the lower electrode plate are respectively connected with positive and negative electrodes of a power supply. By introducing the electric field auxiliary device, the flowability of the resin is greatly improved, so that a high-quality molded part is obtained, the pouring time is effectively saved, and the production period is shortened.

Description

Technical Field

[0001] The invention belongs to the field of fiber-reinforced resin-based composite material molding technology, and specifically relates to a resin infusion device for electrically assisting in improving resin fluidity and an application thereof. Background Art

[0002] Fiber-reinforced resin-based composite materials are widely used in aerospace, shipbuilding, automotive and other fields due to their high specific modulus, high strength, good corrosion resistance and fatigue performance. There are many methods for the molding and preparation of fiber-reinforced composite materials, mainly including hand lay-up molding, autoclave molding and resin transfer molding. As a variant of resin transfer molding, vacuum-assisted resin infusion molding uses a single rigid mold and a flexible vacuum bag to form a vacuum environment. It has the advantages of low cost, low porosity and non-autoclave, so it is widely used in the field of fiber-reinforced composite molding.

[0003] In the process of resin filling, it is known that there is a dual-scale flow, namely Darcy flow on a macro scale and capillary flow on a micro scale. Reasonable control of the flow process can not only save production cycles, but also significantly improve the quality of molded parts. At present, in the vacuum-assisted resin infusion molding process, the main way to regulate the flow of resin is to change the vacuum degree and resin properties. Changes in vacuum degree mean an increase in the requirements for mold stiffness, and the improvement of resin properties also involves additional filler and design costs. Electric field assistance has been used in vacuum resin transfer molding processes, but it is mainly used for electrical curing, which uses the Joule heat of carbon fiber to cure the surrounding resin, and the electric field has not been further applied. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a resin infusion device and application thereof for electrically assisting in improving resin fluidity, which aims to solve the technical problems of poor resin fluidity and high requirements on mold rigidity in the prior art.

[0005] According to a first aspect of the present invention, there is provided a resin infusion device for electrically assisting in improving the fluidity of resin, which specifically comprises an infusion component, a resin inlet and a resin outlet; the infusion component comprises, from bottom to top, a mold, a lower electrode plate, a dielectric layer, a fiber preform, a demolding cloth, an upper electrode plate and a packaging bag; the two ends of the demolding cloth respectively extend downward to contact the mold; the four sides of the packaging bag respectively extend downward to be fixedly connected to the mold; the resin inlet and the resin outlet are respectively located on the upper part of the demolding cloth extending from the two ends; the upper electrode plate and the lower electrode plate are respectively used to connect to the positive and negative poles of a power source.

[0006] Preferably, the resin infusion device also includes a buffer tank, a storage tank and a vacuum pump, the resin inlet is led out from the infusion component through a first material pipe and connected to the buffer tank, and the buffer tank is connected to the vacuum pump; the resin outlet is led out from the infusion component through a second material pipe and connected to the storage tank.

[0007] Preferably, a guide net is further provided between the release cloth and the upper electrode plate; one end of the guide net close to the resin inlet extends downward to contact the release cloth, and the resin inlet is located at the upper part of the extended guide net.

[0008] Preferably, both ends of the packaging bag are fixedly connected to the mold via a sealant.

[0009] Preferably, the upper electrode plate and the lower electrode plate are both connected to a cable, the cable is led out from the injection component through the sealant, and the cable is used to connect to a power source.

[0010] According to another aspect of the present invention, there is provided a method for preparing the resin infusion device for electrically assisting in improving resin fluidity, comprising the following steps:

[0011] (1) laying a lower electrode plate, a dielectric layer, a fiber preform, and a release cloth on a mold in sequence, so that both ends of the release cloth extend downward to contact the mold, and respectively setting a resin inlet and a resin outlet on the upper part of the release cloth extending at both ends, and connecting the resin inlet and the resin outlet to the first material pipe and the second material pipe, respectively;

[0012] (2) then laying an upper electrode plate on the release cloth; connecting the upper electrode plate and the lower electrode plate to electric cables respectively, and connecting the electric cables to a power source after leading them out of the mold;

[0013] (3) Finally, a packaging bag is placed on the upper electrode plate so that the four sides of the packaging bag extend downward to be fixedly connected to the mold.

[0014] Preferably, after step (1), the method further includes leading the first material pipe and the second material pipe out of the mold and connecting them to a buffer tank and a storage tank respectively; and connecting the buffer tank to the vacuum pump.

[0015] Preferably, a guide net is further provided between the release cloth and the upper electrode plate; one end of the guide net close to the resin inlet is extended downward to contact the release cloth, and the resin inlet is provided on the upper part of the extended guide net.

[0016] According to another aspect of the present invention, there is provided an application of the resin infusion device for electrically assisting in improving resin fluidity, which specifically comprises the following steps:

[0017] (1) evacuating the perfusion component with a vacuum pump and maintaining the pressure for a period of time to check the air tightness of the perfusion component;

[0018] (2) The upper electrode plate and the lower electrode plate are connected to the positive and negative electrodes of the power supply respectively, and the infusion component is energized. At the same time, resin is poured into the resin inlet until the resin permeates the entire fiber preform, and the resin inlet is closed and the power supply is maintained; after curing is completed, the power supply is turned off.

[0019] Preferably, the resin is selected from epoxy resin, vinyl ester, phenolic resin or polyurethane.

[0020] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0021] (1) The present invention introduces an electric field auxiliary device to polarize the neutral particles of the resin under the action of the electric field, generate a dielectrophoretic force, and greatly improve the fluidity of the resin, thereby improving the wetting performance between the resin and the fiber preform, further improving the permeability and fluidity of the resin, obtaining high-quality molded parts, effectively saving the infusion time, and shortening the production cycle.

[0022] (2) The resin of the present invention penetrates into the fiber under the combined action of vacuum pressure and dielectrophoretic force to fill the pores in the fiber preform bundle, thereby reducing the pores in the final molded part and improving the mechanical properties of the vacuum-assisted infusion molded part.

[0023] (3) The present invention can achieve the technical effect of improving the fluidity of the resin without adding fillers to the resin or chemically or physically modifying the resin and fiber surfaces, thereby reducing damage to the fiber surface and lowering production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A cross-sectional view of a pouring component of a resin pouring device for electrically assisting in improving resin fluidity according to the present invention.

[0025] Figure 2 This is a schematic diagram of a resin infusion device for electrically assisting in improving resin fluidity according to the present invention.

[0026] In the figure, 1-mold; 2-resin outlet; 3-packaging bag; 4-upper electrode plate; 5-flow guide net; 6-mold release cloth; 7-fiber preform; 8-dielectric layer; 9-lower electrode plate; 10-resin inlet; 11-sealant; 12-pouring component; 13-cable; 14-storage tank; 15-buffer tank; 16-vacuum pump. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] A resin infusion device for electrically assisting the improvement of resin fluidity, specifically comprising an infusion component 12, a resin inlet 10, and a resin outlet 2; the infusion component 12 comprises, from bottom to top, a mold 1, a lower electrode plate 9, a dielectric layer 8, a fiber preform 7, a demoulding cloth 6, an upper electrode plate 4, and a packaging bag 3; the two ends of the demoulding cloth 6 respectively extend downward to contact the mold 1; the four sides of the packaging bag 3 respectively extend downward to be fixedly connected to the mold 1; the resin inlet 10 and the resin outlet 2 are respectively located on the two ends of the extended demoulding cloth 6; the upper electrode plate 4 and the lower electrode plate 9 are respectively connected to the positive and negative poles of a power source.

[0029] In some embodiments, the resin infusion device also includes a buffer tank 15, a storage tank 14 and a vacuum pump 16. The resin inlet 10 is connected to the buffer tank 15 after being led out from the infusion component 12 through a first material pipe, and the buffer tank 15 is connected to the vacuum pump 16; the resin outlet 2 is connected to the storage tank 14 after being led out from the infusion component 12 through a second material pipe.

[0030] In some embodiments, a guide net 5 is further provided between the release cloth 6 and the upper electrode plate 4 ; one end of the guide net 5 close to the resin inlet 10 extends downward to contact the release cloth 6 , and the resin inlet 10 is located at the upper part of the extended guide net 5 .

[0031] In some embodiments, both ends of the packaging bag 3 are fixedly connected to the mold 1 via a sealant 11 .

[0032] In some embodiments, the upper electrode plate 4 and the lower electrode plate 9 are both connected to the cable 13 . The cable 13 is led out from the injection component 12 through the sealant 11 and then connected to a power source.

[0033] In some embodiments, the upper electrode plate 4 and the lower electrode plate 9 are selected from copper, platinum or silver, and the thickness of the upper electrode plate 4 and the lower electrode plate 9 are both 0.4-1 mm.

[0034] In some embodiments, the dielectric layer is one or any combination of polyamide and polyethylene vacuum bag, or polyester, or polytetrafluoroethylene.

[0035] In some embodiments, the fiber is one or any combination of carbon fiber, glass fiber, aramid fiber, flax fiber or basalt fiber.

[0036] In some embodiments, the resin is an epoxy, vinyl ester, phenolic, or polyurethane.

[0037] In some embodiments, the second material tube is a spiral tube.

[0038] Example 1

[0039] Provide a resin infusion device with electrical assistance to improve resin fluidity, referring to Figure 1-2 , specifically including a pouring component 12, a resin inlet 10, a resin outlet 2, a buffer tank 15, a storage tank 14 and a vacuum pump 16; the pouring component 12 is composed of a mold 1, a lower electrode plate 9, a dielectric layer 8, a fiber preform 7, a demoulding cloth 6, a guide net 5, an upper electrode plate 4 and a packaging bag 3 from bottom to top; both ends of the demoulding cloth 6 extend downward to contact the mold 1; one end of the guide net 5 close to the resin inlet 10 extends downward to contact the demoulding cloth 6, and the resin inlet 10 is located on the upper part of the extended guide net 5; the four sides of the packaging bag 3 are fixedly connected to the mold 1 by a sealant 11; the resin outlet 2 is located at the upper end of the extended demoulding cloth 6 away from the resin inlet 10; the upper electrode plate 4 and the lower electrode plate 9 are respectively connected to the positive and negative poles of the power supply through a cable 13. The resin inlet 10 is led out from the pouring component 12 through a first material pipe and connected to a buffer tank 15 , and the buffer tank 15 is connected to the vacuum pump 16 ; the resin outlet 2 is led out from the pouring component 12 through a second material pipe and connected to the storage tank 14 .

[0040] When in use, turn on the vacuum pump 16, evacuate the mold 1, and the packaging bag 3 covers the entire mold 1 under the action of atmospheric pressure, and maintain the pressure for a period of time to check the air tightness; then turn on the power, power on the mold 1, and pour resin into the resin inlet 10 at the same time. Under the action of the electric field, the resin is driven by the dielectrophoretic force and flows rapidly into the gaps in the fiber bundle, while accelerating the flow between the fiber bundles until the entire fiber preform 7 is infiltrated, and close the resin inlet 10; continue to keep the power on, the electric field drives the resin to penetrate into the gaps in the bundle, and after curing is completed, turn off the power.

[0041] Example 2

[0042] A method for preparing a resin infusion device for electrically assisting in improving resin fluidity comprises the following steps:

[0043] (1) Cut the fiber cloth into a suitable size, lay multiple layers of fiber cloth to form a fiber preform 7, lay the lower electrode plate 9, dielectric layer 8, fiber preform 7, release cloth 6, and guide net 5 on the mold 1 in sequence, so that both ends of the release cloth 6 extend downward to contact the mold 1, install the resin outlet 2 on the upper part of one end of the extended release cloth, extend the end of the guide net 5 away from the resin outlet 2 downward to contact the release cloth 6, and set the resin inlet 10 on the upper part of the guide net 5; connect the resin inlet 10 and the resin outlet 2 to the first material pipe and the second material pipe respectively; connect the first material pipe and the second material pipe to the buffer tank 15 and the storage tank 14 respectively after being led out of the mold 1; and connect the buffer tank 15 to the vacuum pump 16.

[0044] (2) Then, the upper electrode plate 4 is laid on the release cloth 6; the upper electrode plate 4 and the lower electrode plate 9 are connected to the cable 13 respectively, and the cable 13 is led out from the mold 1 and connected to a power source;

[0045] (3) Finally, the packaging bag 3 is placed on the upper electrode plate 4 , so that the four sides of the packaging bag 3 are fixedly connected to the mold 1 by using sealants 11 , and the first material pipe, the second material pipe, and the cable are fixed by the sealants 11 .

[0046] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A resin infusion device for electrically assisting the improvement of resin fluidity, characterized in that: The invention comprises a pouring component (12), a resin inlet (10), and a resin outlet (2); the pouring component (12) comprises, from bottom to top, a mold (1), a lower electrode plate (9), a dielectric layer (8), a fiber preform (7), a demoulding cloth (6), an upper electrode plate (4), and a packaging bag (3); the two ends of the demoulding cloth (6) respectively extend downward to contact the mold (1); the four sides of the packaging bag (3) respectively extend downward to be fixedly connected to the mold (1); the resin inlet (10) and the resin outlet (2) are respectively located on the upper part of the demoulding cloth (6) extending at the two ends; the upper electrode plate (4) and the lower electrode plate (9) are respectively used to be connected to the positive and negative poles of a power source.

2. The resin infusion device for electrically assisting in improving resin fluidity according to claim 1, characterized in that: The resin infusion device further comprises a buffer tank (15), a material storage tank (14) and a vacuum pump (16); the resin inlet (10) is connected to the buffer tank (15) after being led out from the infusion component (12) through a first material pipe, and the buffer tank (15) is connected to the vacuum pump (16); the resin outlet (2) is connected to the material storage tank (14) after being led out from the infusion component (12) through a second material pipe.

3. The vacuum resin infusion device for electrically assisting in improving resin fluidity according to claim 1, characterized in that: A flow guide net (5) is also arranged between the demoulding cloth (6) and the upper electrode plate (4); one end of the flow guide net (5) close to the resin inlet (10) extends downward to contact the demoulding cloth (6), and the resin inlet (10) is located at the upper part of the extended flow guide net (5).

4. The resin infusion device for electrically assisting in improving resin fluidity according to claim 1, characterized in that: The two ends of the packaging bag (3) are fixedly connected to the mold (1) via a sealant (11).

5. The resin infusion device for electrically assisting in improving resin fluidity according to claim 1, characterized in that: The upper electrode plate (4) and the lower electrode plate (9) are both connected to a cable (13). The cable (13) is led out from the injection component (12) through the sealant (11). The cable (13) is used to connect to a power source.

6. A method for preparing a resin infusion device for electrically assisting in improving resin fluidity according to any one of claims 1 to 5, characterized in that: The steps include: (1) laying a lower electrode plate, a dielectric layer, a fiber preform, and a release cloth on a mold in sequence, so that both ends of the release cloth extend downward to contact the mold, and respectively setting a resin inlet and a resin outlet on the upper part of the release cloth extending at both ends, and connecting the resin inlet and the resin outlet to the first material pipe and the second material pipe, respectively; (2) then laying an upper electrode plate on the release cloth; The upper electrode plate and the lower electrode plate are connected to electric cables respectively, and the electric cables are led out from the mold and connected to a power source; (3) Finally, a packaging bag is placed on the upper electrode plate so that the four sides of the packaging bag extend downward to be fixedly connected to the mold.

7. The method for preparing a resin infusion device for electrically assisting in improving resin fluidity according to claim 6, characterized in that: After step (1), the method further includes leading the first material pipe and the second material pipe out of the mold and connecting them to a buffer tank and a storage tank respectively; and connecting the buffer tank to the vacuum pump.

8. The method for preparing a resin infusion device for electrically assisting in improving resin fluidity according to claim 7, characterized in that: A guide net is also arranged between the demoulding cloth and the upper electrode plate; one end of the guide net close to the resin inlet is extended downward to contact the demoulding cloth, and the resin inlet is arranged on the upper part of the extended guide net.

9. Application of a resin infusion device for electrically assisting in improving resin fluidity according to any one of claims 1 to 5, characterized in that: The specific steps include: (1) evacuating the perfusion component with a vacuum pump and maintaining the pressure for a period of time to check the air tightness of the perfusion component; (2) The upper electrode plate and the lower electrode plate are connected to the positive and negative electrodes of the power supply respectively, and the infusion component is energized. At the same time, resin is poured into the resin inlet until the resin permeates the entire fiber preform, and the resin inlet is closed and the power supply is maintained; after curing is completed, the power supply is turned off.

10. Application of the resin infusion device for electrically assisting in improving resin fluidity according to claim 9, characterized in that: The resin is selected from epoxy resin, vinyl ester, phenolic resin or polyurethane.

Images