Large carbon fiber structure application high viscosity vinyl resin integrated molding process

Abstract

The application discloses a large carbon fiber structure application high-viscosity vinyl resin integrated forming process and relates to the field of large carbon fiber part manufacturing processes.The large carbon fiber structure application high-viscosity vinyl resin integrated forming process is provided with an innovative vacuum flow guide process method, including a PVC core material splicing and slotting method in a carbon fiber composite material and an innovative design of a vacuum glue injection dual-purpose pipe, when the PVC core material is laid, a gap channel is reserved between core material splicing, resin in vacuum pouring can be better injected and flowed, meanwhile, a plurality of vacuum glue injection dual-purpose pipes are arranged in the vacuum system, so that the large carbon fiber structure part can be integrally formed at one time, the overall quality and strength are improved in the whole process, and the manufacturing cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of large carbon fiber component manufacturing technology, specifically to the application of high-viscosity vinyl ester resin integral molding process for large carbon fiber structures. Background Technology

[0002] Traditional carbon fiber component manufacturing typically involves bonding it with epoxy resin and then curing it with the epoxy resin to form a carbon fiber structure.

[0003] However, due to the properties of epoxy resin, it must be heated in an oven for curing, which makes the production cost of large carbon fiber structures using epoxy resin extremely high and impractical. The structure must be disassembled into multiple small pieces and then spliced ​​together, which is a complicated production process. The strength of the spliced ​​parts is not as high as that of the whole piece. Therefore, a high-viscosity vinyl ester resin integral molding process is provided for large carbon fiber structures to solve the above problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a one-piece molding process for large carbon fiber structures using high-viscosity vinyl ester resin. This solves the problems that using epoxy resin for large carbon fiber structures is extremely costly and impractical, requiring the structure to be disassembled into multiple small pieces for fabrication and then spliced ​​together, resulting in cumbersome production processes and lower strength of the spliced ​​parts compared to the overall component.

[0005] To achieve the above objectives, the present invention employs the following technical solution: a high-viscosity vinyl ester resin integral molding process for large carbon fiber structures, comprising the following steps:

[0006] Step 1: Mold pretreatment. Thoroughly clean the molds for large structures and apply multiple layers of release wax.

[0007] Step 2: Applying the outer carbon fiber layer. After the release wax has dried, apply the required outer carbon fiber material.

[0008] Step 3: Cut and lay the PVC core. After the carbon fiber material is laid, cut and lay the PVC core material according to the mold line of the large structure, and then clean the surface of the PVC core material.

[0009] Step 4: Laying the upper layer of carbon fiber. Lay the upper layer of carbon fiber material according to the design drawings.

[0010] Step 5: Lay the release cloth on the surface. After the inner carbon fiber material is laid, lay the release cloth on its surface.

[0011] Step 6: Mark the position of the Omega-type flow guide tube. Mark the position of the Omega-type flow guide tube for resin flow on the release cloth. The position is set above the splice seam of the core material, with an interval of 50mm. The position is obtained by observing the splice position of the core material through the interface and by calculating the width of the core material.

[0012] Step 7: Lay the flow guide net, flow guide pipe and tee pipe. The core material splicing leaves a gap for resin flow as a flow channel. Lay a 50mm wide flow guide net and the flow guide pipe above it at the marked Omega type flow guide pipe position. Make a hole above the Omega flow guide pipe and pre-embed a tee pipe as the subsequent resin injection point. This point is the glue injection pipe connection point.

[0013] Step 8: Cover with vacuum bag film. Cover the entire mold with vacuum bag film and seal the edges with adhesive to secure it.

[0014] Step 9: Install resin injection tubes. Install resin injection tubes and vacuum tubes at both ends of the tee pipe. By installing valves, the resin injection tubes and vacuum tubes are used for resin injection and vacuuming, respectively.

[0015] Step 10: Vacuuming. Vacuum the entire product using a vacuum tube. The vacuum level should not exceed -0.09 MPa. After vacuuming, perform a pressure holding test on the entire product and the vacuum system.

[0016] Step 11: Inject resin. Place each injection tube into an independent resin tank and guide the resin into the composite material product in an orderly manner for vacuum injection.

[0017] Step 12: Remove the covering. After the resin is poured and cured, remove the resin injection tube, vacuum tube, vacuum bag film and release cloth from the product surface. At this time, the vacuum pouring construction of large structures is completed.

[0018] Preferably, in step three, when cutting the PVC sandwich core, a targeted cutting and splicing scheme is used for the core material for mold areas of different shapes, so as to ensure sufficient bonding between the resin flow and the carbon fiber during subsequent resin vacuum diversion.

[0019] Preferably, the cutting and splicing scheme of the core material includes the following steps;

[0020] S1. The core material must first be cut into four standard width dimensions perpendicular to the direction of the original design guide channel. The four standard width dimensions are 420mm, 210mm, 100mm and 51mm.

[0021] S2. After the cutting is prepared, a 1.5mm thick core material waste sheet is attached to the cut surface to serve as a resin flow channel gap groove during subsequent core material laying.

[0022] S3. For the ordinary flat area of ​​the mold, a core material with a width of 420mm can be used directly and laid directly on the carbon fiber cloth. The core materials are bonded together with hot melt adhesive.

[0023] S4. For the vertical area with good mold flatness, use wooden blocks combined with slings as temporary hangers, and fix the carbon fiber and core material above with rivets. Here, a core material with a width of 420mm is used. The two widths of core material are temporarily connected with self-tapping screws, and then they are glued together at multiple points with hot melt glue.

[0024] S5. For areas with a certain bending angle in the mold, a core material with a width of 51mm should be selected according to the bending situation. One side of the core material should be cut at 5° to 25° and bonded to the straight side of another core material of the same width to achieve the arc angle of splicing. Hot melt adhesive should be used to bond the core material at multiple points to fix it.

[0025] S6. For areas in the mold where the bending angle changes drastically, especially inward bending profiles, based on step S5, reduce the core material width from 51mm and use small triangular core material pieces to fill and lay the material in areas with extremely large corner curvatures.

[0026] Preferably, in steps S3 and S4, the seams of the core material in the longitudinal direction should be staggered to avoid the weak points of the core material being concentrated in a straight line.

[0027] Preferably, in step four, for facades and carbon fiber materials that cannot be laid naturally by gravity, adhesive spraying and rivets should be used to connect and fix them to the core material.

[0028] Preferably, in step six, if the laid release cloth cannot adhere to the carbon fiber material by gravity, it is temporarily bonded and fixed by spray adhesive.

[0029] Preferably, in step seven, the Omega guide tubes on the same straight line are connected by a spiral guide tube.

[0030] Preferably, in step 11, the number and location of the resin injection points should be arranged according to different molds and product characteristics. For products with vertical height, the injection should start from the bottom of the product to ensure that the resin at each injection point flows upward synchronously, avoiding the resin "backflow" and forming white spot areas due to excessive flow on one side. During the injection process, the resin injection tube is used to adjust the resin flow rate in local areas and the overall synchronization.

[0031] This invention discloses a one-piece molding process for large carbon fiber structures using high-viscosity vinyl ester resin, which has the following beneficial effects:

[0032] 1. This large carbon fiber structure uses a high-viscosity vinyl ester resin one-piece molding process. Through the material laying process and the new design of the vacuum infusion system, it can solve the problem of fully impregnating the carbon fiber in the large structural component with the high-viscosity high-strength vinyl ester resin without relying on a large area of ​​guide net, thereby realizing the one-time molding of the large carbon fiber structural component.

[0033] 2. This large carbon fiber structure uses a high-viscosity vinyl ester resin integral molding process. When laying the mold for the curved surface, compared with the traditional process of fitting the curved surface by grooving and bending the core material on one side, or directly using grooved core material with felt to lay on the mold surface, the new core material process can effectively reduce the gap between core materials without hindering resin flow, reduce resin accumulation in the curved area, reduce the fragile area of ​​the product and the resin content, thereby improving product quality and reducing costs.

[0034] 3. This large carbon fiber structure utilizes a high-viscosity vinyl ester resin integral molding process, forming resin flow channels between the core materials. Therefore, even with a reduced amount of resin flow mesh, smooth resin flow is still guaranteed. Furthermore, it avoids the problem of excessively large flow mesh causing resin to flow too quickly, potentially leading to localized reverse wrapping and resulting in "white spots" where fibers fail to be impregnated with resin. This significantly improves product yield and eliminates the need for multiple components to be fabricated and reassembled, greatly saving production costs and ensuring product quality and strength. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of the molding process of the present invention;

[0037] Figure 2 This is a comparison diagram of the core material splicing process of this invention and the traditional ordinary bending core material process;

[0038] Figure 3 This is a comparison diagram of the core material splicing process of the present invention and the traditional process of laying felt core materials;

[0039] Figure 4 This is a schematic diagram of the Omega tube assembly structure of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] This application provides a high-viscosity vinyl ester resin integral molding process for large carbon fiber structures, which solves the problems that using epoxy resin for large carbon fiber structures is extremely costly and impractical, requires disassembling the structure into multiple small pieces for fabrication and then splicing them together, resulting in a complicated production process and lower strength of the spliced ​​parts compared to the integral components.

[0042] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0043] This invention discloses a one-piece molding process using high-viscosity vinyl ester resin for large carbon fiber structures.

[0044] According to the appendix Figure 1-4 As shown, it includes the following steps:

[0045] Step 1: Mold pretreatment. Thoroughly clean the molds for large structures and apply multiple layers of release wax.

[0046] Step 2: Applying the outer carbon fiber layer. After the release wax has dried, apply the required outer carbon fiber material.

[0047] Step 3: Cut and lay the PVC core. After the carbon fiber material is laid, cut and lay the PVC core material according to the mold line of the large structure, and then clean the surface of the PVC core material.

[0048] Step 4: Laying the upper layer of carbon fiber. Lay the upper layer of carbon fiber material according to the design drawings. For vertical surfaces and carbon fiber materials that cannot be laid naturally by gravity, use spray adhesive and rivets to connect and fix them to the core material.

[0049] Step 5: Lay the release cloth on the surface. After the inner carbon fiber material is laid, lay the release cloth on its surface.

[0050] Step 6: Mark the position of the Omega-type flow guide tube. Mark the position of the Omega-type flow guide tube for resin flow on the release cloth. The position is set above the splice seam of the core material, with an interval of 50mm. The position is determined by observing the splice position of the core material through the interface and by calculating the width of the core material. If the released cloth cannot adhere to the carbon fiber material by gravity, it should be temporarily fixed by spray adhesive.

[0051] Step 7: Lay out the flow guide net, flow guide pipe and tee pipe. The core material splicing leaves a gap for resin flow as a flow channel. Lay out the flow guide net with a width of 50mm and the flow guide pipe above it at the marked Omega type flow guide pipe position. Make a hole above the Omega flow guide pipe and pre-embed a tee pipe as the subsequent resin injection point. This point is the glue injection pipe connection point. The Omega flow guide pipes on the same straight line are connected by a spiral flow guide pipe.

[0052] Step 8: Cover with vacuum bag film. Cover the entire mold with vacuum bag film and seal the edges with adhesive to secure it.

[0053] Step 9: Install resin injection tubes. Install resin injection tubes and vacuum tubes at both ends of the tee pipe. By installing valves, the resin injection tubes and vacuum tubes are used for resin injection and vacuuming, respectively.

[0054] Step 10: Vacuuming. Vacuum the entire product using a vacuum tube. The vacuum level should not exceed -0.09 MPa. After vacuuming, perform a pressure holding test on the entire product and the vacuum system.

[0055] Step 11: Resin Injection. Place each injection tube into an independent resin tank and guide the resin into the composite material product for vacuum injection. The number and location of the injection points should be arranged according to different molds and product characteristics. For products with vertical height, injection should start from the bottom of the product to ensure that the resin at each injection point flows upward synchronously, avoiding excessive flow on one side that could cause resin "backflow" and form white spots. During the injection process, use the resin injection tubes to adjust the resin flow rate in local areas and the overall synchronization.

[0056] Step 12: Remove the covering. After the resin is poured and cured, remove the resin injection tube, vacuum tube, vacuum bag film and release cloth from the product surface. At this time, the vacuum pouring construction of large structures is completed.

[0057] In step three, when cutting the PVC sandwich core, a targeted cutting and splicing scheme is used for the core material for different shaped mold areas to ensure sufficient resin flow and bonding with carbon fiber during subsequent resin vacuum diversion.

[0058] The core material cutting and splicing scheme includes the following steps;

[0059] S1. The core material must first be cut into four standard width dimensions perpendicular to the direction of the original design guide channel. The four standard width dimensions are 420mm, 210mm, 100mm and 51mm.

[0060] S2. After the cutting is prepared, a 1.5mm thick core material waste sheet is attached to the cut surface to serve as a resin flow channel gap groove during subsequent core material laying.

[0061] S3. For the ordinary flat area of ​​the mold, a core material with a width of 420mm can be used directly and laid directly on the carbon fiber cloth. Hot melt adhesive is used to bond the core materials together. The seams of the core materials in the longitudinal direction should be staggered to avoid the weak points of the core materials being concentrated in a straight line.

[0062] S4. For vertical areas with good mold flatness, use wooden blocks combined with slings as temporary hangers. Fix carbon fiber and core material to the top with rivets. Use 420mm wide core material here. Connect two widths of core material temporarily with self-tapping screws, and then use hot melt glue to bond them together at multiple points. The seams of the core material in the longitudinal direction should be staggered to avoid the weak points of the core material being concentrated on a straight line.

[0063] S5. For areas with a certain bending angle in the mold, a core material with a width of 51mm should be selected according to the bending situation. One side of the core material should be cut at 5° to 25° and bonded to the straight side of another core material of the same width to achieve the arc angle of splicing. Hot melt adhesive should be used to bond the core material at multiple points to fix it.

[0064] S6. For areas in the mold where the bending angle changes drastically, especially inward bending profiles, based on step S5, reduce the core material width from 51mm and use small triangular core material pieces to fill and lay the material in areas with extremely large corner curvatures.

[0065] In summary, compared with existing technologies, it has the following beneficial effects:

[0066] On the one hand, this process utilizes the room-temperature curing properties of vinyl ester resin, significantly reducing the cost associated with heating and curing epoxy resin used in conventional carbon fiber materials. This makes the manufacturing of large carbon fiber structures highly operable and significantly reduces costs. On the other hand, this process effectively eliminates the technical challenge of high-strength vinyl ester resin having high viscosity and difficulty in impregnating carbon fiber materials. It is suitable for molds with various shapes and designs, and improves product molding quality, including reducing the amount of resin used in curved areas and the amount of flow guide mesh, thus greatly improving the product yield.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A large carbon fiber structure using a high-viscosity vinyl ester resin integral molding process, characterized in that, Includes the following steps: Step 1: Mold pretreatment. Thoroughly clean the molds for large structures and apply multiple layers of release wax. Step 2: Applying the outer carbon fiber layer. After the release wax has dried, apply the required outer carbon fiber material. Step 3: Cut and lay the PVC core. After the carbon fiber material is laid, cut and lay the PVC core material according to the mold line of the large structure, and then clean the surface of the PVC core material. Step 4: Laying the upper layer of carbon fiber. Lay the upper layer of carbon fiber material according to the design drawings. Step 5: Lay the release cloth on the surface. After the inner carbon fiber material is laid, lay the release cloth on its surface. Step 6: Mark the position of the Omega-type flow guide tube. Mark the position of the Omega-type flow guide tube for resin flow on the release cloth. The position is set above the splice seam of the core material, with an interval of 50mm. The position is obtained by observing the splice position of the core material through the interface and by calculating the width of the core material. Step 7: Lay the flow guide net, flow guide pipe and tee pipe. The core material splicing leaves a gap for resin flow as a flow channel. Lay a 50mm wide flow guide net and the flow guide pipe above it at the marked Omega type flow guide pipe position. Make a hole above the Omega flow guide pipe and pre-embed a tee pipe as the subsequent resin injection point. This point is the glue injection pipe connection point. Step 8: Cover with vacuum bag film. Cover the entire mold with vacuum bag film and seal the edges with adhesive to secure it. Step 9: Install resin injection tubes. Install resin injection tubes and vacuum tubes at both ends of the tee pipe. By installing valves, the resin injection tubes and vacuum tubes are used for resin injection and vacuuming, respectively. Step 10: Vacuuming. Vacuum the entire product using a vacuum tube. The vacuum level should not exceed -0.09 MPa. After vacuuming, perform a pressure holding test on the entire product and the vacuum system. Step 11: Inject resin. Place each injection tube into an independent resin tank and guide the resin into the composite material product in an orderly manner for vacuum injection. Step 12: Remove the covering. After the resin is poured and cured, remove the resin injection tube, vacuum tube, vacuum bag film and release cloth from the surface of the product. At this time, the vacuum pouring construction of large structures is completed. In step three, when cutting the PVC sandwich core, a targeted cutting and splicing scheme is used for the core material for different shaped mold areas to ensure sufficient resin flow and bonding with carbon fiber during subsequent resin vacuum diversion. The cutting and splicing scheme for the core material includes the following steps; S1. The core material must first be cut into four standard width dimensions perpendicular to the direction of the original design guide channel. The four standard width dimensions are 420mm, 210mm, 100mm and 51mm. S2. After the cutting is prepared, a 1.5mm thick core material waste sheet is attached to the cut surface to serve as a resin flow channel gap groove during subsequent core material laying. S3. For the ordinary flat area of ​​the mold, use a core material with a width of 420mm directly and lay it directly on the carbon fiber cloth. Use hot melt adhesive to bond the core materials together. S4. For the vertical area with good mold flatness, use wooden blocks combined with slings as temporary hangers, and fix the carbon fiber and core material above with rivets. Here, a core material with a width of 420mm is used. The two widths of core material are temporarily connected with self-tapping screws, and then they are glued together at multiple points with hot melt glue. S5. For areas with a certain bending angle in the mold, a core material with a width of 51mm should be selected according to the bending situation. One side of the core material should be cut at 5° to 25° and bonded to the straight side of another core material of the same width to achieve the arc angle of splicing. Hot melt adhesive should be used to bond the core material at multiple points to fix it. S6. For areas in the mold where the bending angle changes drastically, including areas with inward bending profiles, based on step S5, reduce the core material width from 51mm and use small triangular core material pieces to fill and lay the material in areas with extremely large corner curvatures.

2. The large carbon fiber structure according to claim 1 uses a high-viscosity vinyl ester resin integral molding process, characterized in that: In steps S3 and S4, the seams of the core material in the longitudinal direction should be staggered to avoid the weak points of the core material being concentrated in a straight line.

3. The large carbon fiber structure according to claim 1 uses a high-viscosity vinyl ester resin integral molding process, characterized in that: In step four, for facades and carbon fiber materials that cannot be laid naturally by gravity, adhesive spraying and rivets should be used to connect and fix them to the core material.

4. The large carbon fiber structure according to claim 1 uses a high-viscosity vinyl ester resin integral molding process, characterized in that: In step six, if the release cloth cannot adhere to the carbon fiber material by gravity, it should be temporarily bonded and fixed using spray adhesive.

5. The large carbon fiber structure according to claim 1 uses a high-viscosity vinyl ester resin integral molding process, characterized in that: In step seven, the Omega guide tubes on the same straight line are connected by a spiral guide tube.

6. The large carbon fiber structure according to claim 1 uses a high-viscosity vinyl ester resin integral molding process, characterized in that: In step eleven, the number and location of the resin injection points should be arranged according to different molds and product characteristics. For products with vertical height, the injection should start from the bottom of the product to ensure that the resin at each injection point flows upward synchronously, avoiding the resin "backflow" and forming white spot areas due to excessive flow on one side. During the injection process, the resin injection tube is used to adjust the resin flow rate in local areas and the overall synchronization.

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