Method for integrally forming frame of fuel cell

Abstract

The invention relates to a method for integrally forming a fuel cell frame. The method comprises the following steps: manufacturing an ultra-thin frame injection mold according to the outline of an ultra-thin frame finished product; cutting the fiber cloth according to the outline of the maximum part of the ultrathin frame finished product to obtain a fiber cloth bone felt; putting the fiber cloth bone felt into a cavity of an injection mold, closing the mold, vacuumizing, pumping molten vinyl resin into the cavity of the injection mold by an injection molding machine, and slowly curing the vinyl resin after all the vinyl resin is pumped into the cavity of the injection mold; and after the curing time is over, opening the mold, taking out the injection molded part, and cooling to obtain an ultrathin frame finished product. According to the method, the fuel cell frame with a more complex surface structure can be prepared, the preparation time of the frame can be greatly shortened, the service life of the obtained finished product in the field of fuel cells can be prolonged, the requirement for injection molding equipment is low, the injection molding process is simple, and the size stability of the finished product is excellent.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and specifically discloses a method for integrally molding a fuel cell frame. Background Technology

[0002] The frame of a fuel cell plays a crucial role in sealing and supporting the structure, which places extremely high demands on the frame's structural strength, corrosion resistance, insulation performance, and lifespan. With the development of fuel cells, there are increasingly more complex structural requirements, faster manufacturing processes, lower costs, and longer lifespans required for fuel cell frames.

[0003] At present, in order to match the structure of a single cell, conventional processes mostly use PEN (polyethylene naphthalate) frame film material to laminate multiple layers to prepare the frame. After the frame is prepared, since the thinnest part of the frame is only 0.04mm and the thickest part can reach 0.6mm, the frame prepared by conventional processes cannot be modified with complex surface structures. Moreover, the more thick the structure, the more layers of frame film material are laminated.

[0004] Currently, most conventional frames are made by laminating 4-8 layers of frame film. Frames made by laminating multiple layers of frame film have drawbacks such as long processing time, low production efficiency, and inability to modify complex surface structures. At the same time, due to the high price of PEN film, the lamination of multiple layers of PEN film of different thicknesses prevents the price of the frame from being reduced. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for integrally molding a fuel cell frame.

[0006] According to the technical solution provided by the present invention, the method for integrally molding the fuel cell frame includes the following steps: Step 1: Create an ultra-thin frame injection mold according to the outline of the finished ultra-thin frame. Step 2: Provide fiber cloth. The thickness of the fiber cloth is less than the thinnest part of the finished ultra-thin frame. Cut the fiber cloth according to the maximum outline of the finished ultra-thin frame to obtain fiber cloth felt. Step 3: Place the fiber cloth felt into the cavity of the injection mold, close the mold, control the temperature of the injection mold at 80-150℃, draw a vacuum, control the vacuum degree of the injection mold cavity to less than -0.098mpa, and the injection molding machine pumps the molten vinyl resin into the cavity of the injection mold. After all the vinyl resin is pumped in, allow the vinyl resin to cure slowly, and control the curing time to 3-10 minutes. Step 4: After the curing time is over, open the mold, remove the injection molded part and let it cool to obtain the ultra-thin frame finished product.

[0007] Preferably, the fiber cloth is made of glass fiber cloth or carbon fiber cloth.

[0008] Preferably, the vinyl resin is an epoxy vinyl resin or an acrylic vinyl resin.

[0009] The method of this invention can prepare fuel cell frames with more complex surface structures, significantly shorten the preparation time of the frames, extend the service life of the finished product in the field of fuel cells, have low requirements for injection molding equipment, have a simple injection molding process, and produce excellent dimensional stability of the finished product. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. 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.

[0011] Example 1 A method for integrally molding a fuel cell frame, the method comprising the following steps: Step 1: Create an ultra-thin frame injection mold according to the outline of the finished ultra-thin frame. Step 2: Provide fiberglass cloth. The thickness of the fiberglass cloth is less than the thinnest part of the finished ultra-thin frame. Cut the fiberglass cloth according to the maximum outline of the finished ultra-thin frame to obtain fiberglass cloth bone felt. Step 3: Place the fiberglass cloth bone mat into the cavity of the injection mold, close the mold, control the temperature of the injection mold at 80-100℃, draw a vacuum, and control the vacuum degree of the injection mold cavity to less than -0.098mpa. The injection molding machine pumps the molten epoxy vinyl resin into the cavity of the injection mold. After all the epoxy vinyl resin is pumped in, it is allowed to cure slowly, and the curing time is controlled at 3-5 minutes. Step 4: After the curing time is over, open the mold, remove the injection molded part and let it cool to obtain the ultra-thin frame finished product.

[0012] Example 2 A method for integrally molding a fuel cell frame, the method comprising the following steps: Step 1: Create an ultra-thin frame injection mold according to the outline of the finished ultra-thin frame. Step 2: Provide carbon fiber cloth. The thickness of the carbon fiber cloth is less than the thinnest part of the finished ultra-thin frame. Cut the carbon fiber cloth according to the maximum outline of the finished ultra-thin frame to obtain carbon fiber felt. Step 3: Place the carbon fiber felt into the cavity of the injection mold, close the mold, control the temperature of the injection mold at 100-120℃, draw a vacuum, and control the vacuum degree of the injection mold cavity to less than -0.098 MPa. The injection molding machine pumps the molten acrylic vinyl resin into the cavity of the injection mold. After all the acrylic vinyl resin has been pumped in, it is allowed to cure slowly, and the curing time is controlled at 5-7 minutes. Step 4: After the curing time is over, open the mold, remove the injection molded part and let it cool to obtain the ultra-thin frame finished product.

[0013] Example 3 A method for integrally molding a fuel cell frame, the method comprising the following steps: Step 1: Create an ultra-thin frame injection mold according to the outline of the finished ultra-thin frame. Step 2: Provide fiberglass cloth. The thickness of the fiberglass cloth is less than the thinnest part of the finished ultra-thin frame. Cut the fiberglass cloth according to the maximum outline of the finished ultra-thin frame to obtain fiberglass cloth bone felt. Step 3: Place the fiberglass cloth bone mat into the cavity of the injection mold, close the mold, control the temperature of the injection mold at 120-140℃, draw a vacuum, and control the vacuum degree of the injection mold cavity to less than -0.098mpa. The injection molding machine pumps the molten acrylic vinyl resin into the cavity of the injection mold. After all the acrylic vinyl resin has been pumped in, it is allowed to cure slowly, and the curing time is controlled at 7-9 minutes. Step 4: After the curing time is over, open the mold, remove the injection molded part and let it cool to obtain the ultra-thin frame finished product.

[0014] Example 4 A method for integrally molding a fuel cell frame, the method comprising the following steps: Step 1: Create an ultra-thin frame injection mold according to the outline of the finished ultra-thin frame. Step 2: Provide carbon fiber cloth. The thickness of the carbon fiber cloth is less than the thinnest part of the finished ultra-thin frame. Cut the carbon fiber cloth according to the maximum outline of the finished ultra-thin frame to obtain carbon fiber felt. Step 3: Place the carbon fiber felt into the cavity of the injection mold, close the mold, control the temperature of the injection mold at 140-150℃, draw a vacuum, and control the vacuum degree of the injection mold cavity to less than -0.098 MPa. The injection molding machine pumps the molten epoxy vinyl resin into the cavity of the injection mold. After all the epoxy vinyl resin is pumped in, it is allowed to cure slowly, and the curing time is controlled at 9-10 minutes. Step 4: After the curing time is over, open the mold, remove the injection molded part and let it cool to obtain the ultra-thin frame finished product.

[0015] The present invention has the following advantages: 1. Compared with the process of preparing membrane electrodes by multilayer bonding of PEN material, the present invention directly injection molds the fuel cell frame by preparing the frame skeleton by die-cutting fiber cloth and then injection molding and curing vinyl resin. At the same time, the fuel cell frame with more complex surface structure can be prepared by adjusting the structure of the injection mold.

[0016] 2. With the composite injection molding process of the present invention, the preparation time of the membrane electrode assembly is only affected by the injection molding time. Compared with the current multi-layer frame bonding process, the preparation process and time of the fuel cell frame are greatly shortened.

[0017] 3. Vinyl ester resin is widely used in heavy-duty anti-corrosion applications. It has outstanding resistance to acids and alkalis and has better acid corrosion resistance than PEN materials, which can extend the service life of frame materials in fuel cell applications.

[0018] 4. Vinyl resin viscosity can reach below 1000 mPa·s, has excellent fluidity, low requirements for injection molding equipment, simple injection molding process, and excellent dimensional stability of finished products.

[0019] 5. High-quality vinyl ester resin generally costs 15-20 yuan / kg, while 0.1mm thick fiber cloth generally costs 10-100 yuan / m depending on the material. 2 The price of 45μm thick PEN membrane material is generally around 60 yuan / m. 2 The above calculations show that, based on a frame measuring 500mm*200mm*0.5mm, the cost of injection molding is approximately 30-40 yuan per piece, while the cost of multi-layer frame lamination is over 130 yuan per piece. Therefore, this invention can reduce the production cost of ultra-thin frames.

[0020] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for integrally molding a fuel cell frame, characterized in that: The method includes the following steps: Step 1: Create an ultra-thin frame injection mold according to the outline of the finished ultra-thin frame. Step 2: Provide fiber cloth. The thickness of the fiber cloth is less than the thinnest part of the finished ultra-thin frame. Cut the fiber cloth according to the maximum outline of the finished ultra-thin frame to obtain fiber cloth felt. Step 3: Place the fiber cloth felt into the cavity of the injection mold, close the mold, control the temperature of the injection mold at 80-150℃, draw a vacuum, control the vacuum degree of the injection mold cavity to less than -0.098mpa, and the injection molding machine pumps the molten vinyl resin into the cavity of the injection mold. After all the vinyl resin is pumped in, allow the vinyl resin to cure slowly, and control the curing time to 3-10 minutes. Step 4: After the curing time is over, open the mold, remove the injection molded part and let it cool to obtain the ultra-thin frame finished product.

2. The method for integrally molding the fuel cell frame as described in claim 1, characterized in that: The fiber cloth is made of glass fiber or carbon fiber.

3. The method for integrally molding the fuel cell frame as described in claim 1, characterized in that: The vinyl resin is either an epoxy vinyl resin or an acrylic vinyl resin.