Injection molding apparatus and injection molding method for manufacturing bipolar plates and sealing portions surrounding bipolar plates.

Abstract

This invention relates to an injection molding apparatus (10) for manufacturing a bipolar plate (20) and a sealing portion (30) surrounding the bipolar plate (20). The injection molding apparatus (10) has a first injection molding die component (40) and a second injection molding die component (50), which are movable relative to each other. The first injection molding die component (40) and the second injection molding die component (50) form a first cavity (60) for manufacturing the bipolar plate (20) and a second cavity (70) for manufacturing the sealing portion (30) surrounding the bipolar plate (20) at the injection position of the injection molding apparatus (10). The invention also relates to an injection molding method (100) for manufacturing the bipolar plate (20) and the sealing portion (30) surrounding the bipolar plate (20) using such an injection molding apparatus (10).

Description

Technical Field

[0001] This invention relates to an injection molding apparatus for manufacturing a bipolar plate and a sealing portion surrounding the bipolar plate, as described in claim 1. The invention also relates to an injection molding method for manufacturing a bipolar plate and a sealing portion surrounding the bipolar plate using such an injection molding apparatus. Background Technology

[0002] A single fuel cell, especially a PEM fuel cell, typically consists of two current-delivering plates, two catalytic gas diffusion electrodes, and an ion exchange membrane disposed between these gas diffusion electrodes. The current-delivering plates contain means for supplying and distributing reactants.

[0003] Because the voltage of a single fuel cell is too low for practical applications, a large number of such cells are connected in series. This series-connected circuit is also known as a fuel cell stack or fuel cell module.

[0004] In a fuel cell stack, the current-carrying plates that meet are replaced by so-called bipolar plates. One of the surfaces of the bipolar plate is in electrical contact with the anode of one of the fuel cells in the stack, while the opposite surface is in contact with the cathode of the adjacent fuel cell.

[0005] The bipolar plate's function is essentially to conduct current through the fuel cell stack and separate the reactant gases.

[0006] Maintaining a durable seal, especially for the anode and cathode chambers, poses a significant challenge when manufacturing bipolar plates or fuel cell stacks.

[0007] One possibility for sealing the anode and cathode chambers is to manufacture elastomeric seals and arrange these seals between the ion exchange membrane and the bipolar plates. In this case, the seals are manufactured in a complex manner and placed within slots in the bipolar plates.

[0008] Another possibility is described in patent document EP 1 437 780 A2. This patent document discloses an injection molding method with multiple process steps, wherein a bipolar plate is manufactured from a conductive metal plate and subsequently an elastomeric seal is provided. However, the described method has too many sequentially connected process steps, especially individual manufacturing steps, and is therefore very time-consuming and costly, thereby increasing the number of sources of error.

[0009] Furthermore, the elastomeric seal lacks adhesion to the bipolar plate, leading to leakage in the boundary layer between the elastomeric seal and the bipolar plate. These leaks result in a significant reduction in the efficiency of the fuel cell stack during subsequent assembly.

[0010] DE 10 2005 012 057 A1 describes a bipolar plate manufactured by pressing, consisting of a thermosetting epoxy or phenolic resin with a filler content of 60%. However, the manufactured bipolar plate has too large a layer thickness, resulting in a very long flow path around the edge of the thick bipolar plate. Therefore, the diameter of the sealing cavity must be designed to be correspondingly large in order to completely fill it. This creates a joint seam, which can also lead to leakage. Furthermore, the temperature resistance of the bipolar plate terminates below 100°C.

[0011] Since bipolar plates are key functional components of fuel cell stacks and significantly influence the weight, cost, and efficiency of fuel cell stacks, there is a great demand for hermetically sealed bipolar plates with small layer thickness. Summary of the Invention

[0012] According to a first aspect of the invention, an injection molding apparatus for manufacturing a bipolar plate and a sealing portion surrounding the bipolar plate is provided. The injection molding apparatus includes a first injection molding die component and a second injection molding die component, wherein the first injection molding die component and the second injection molding die component are movable relative to each other.

[0013] The first injection molding die component and the second injection molding die component form a first cavity for manufacturing a bipolar plate and a second cavity for manufacturing a sealing portion surrounding the bipolar plate at the injection position of the injection molding device.

[0014] The injection molding apparatus according to the present invention has the following significant advantages: due to the limitation or configuration of the two cavities, two parts can be manufactured by the same apparatus, thereby significantly reducing time and cost expenditures.

[0015] In particular, bipolar plates with a surrounding, seamless, and attached seal can be manufactured using the injection molding apparatus according to the invention. The tedious and complex sequential connection steps, especially separate manufacturing steps, used in the prior art for manufacturing and mounting the seal onto the bipolar plate are eliminated. The injection molding apparatus according to the invention significantly reduces the number of error sources.

[0016] In particular, by means of the injection molding apparatus according to the invention, the diameter of the sealing portion can be designed to be correspondingly thin, so that a very thin arrangement can be produced when the bipolar plates are subsequently assembled into a fuel cell stack, thereby improving the overall efficiency of the fuel cell stack, especially the power density of each bipolar plate.

[0017] Other features and advantages of the invention are set forth below.

[0018] In order to manufacture the first component, especially the thin bipolar plate, by means of the injection molding apparatus according to the invention, the first cavity is preferably shaped as a thin cuboid, especially as a thin plate.

[0019] In order to manufacture the second component, especially the sealing portion surrounding the bipolar plate, using the same device, the shape of the second cavity is preferably larger than that of the first cavity, such that the shape of the second cavity has at least the shape of the first cavity, and the shape of the first cavity is further extended by a surrounding frame, especially a T-shaped frame.

[0020] The temperature resistance of bipolar plates known from the prior art ends below 100°C. However, the injection molding apparatus according to the present invention aims to provide a thin bipolar plate with higher temperature resistance. This can be achieved by heat treating the bipolar plate, especially by temperature regulation or curing. For this purpose, the first and second injection molding die components are preferably heatable to a temperature between 160°C and 200°C, and particularly to a temperature of 180°C.

[0021] The injection molding apparatus according to the invention preferably has a first injection unit for injecting a first injectable filler component. Here, the first injection unit is connected to a first cavity via at least one first injection channel. Alternatively, the first injection unit may be connected to the first cavity via multiple injection channels.

[0022] Preferably, the first injection unit is configured for injection molding of bulk composite plastics, especially long glass fiber and / or carbon fiber reinforced plastics, as the first filler component capable of injection molding. Such plastics are readily heat-treated and possess very high strength after curing. This is particularly important because the bipolar plates need to be constructed to be very thin.

[0023] The injection molding apparatus according to the invention preferably includes a second injection unit for injecting a second injectable filler component. Here, the second injection unit is connected to a second cavity via at least one second injection channel. Alternatively, the second injection unit may be connected to the second cavity via multiple injection channels.

[0024] Preferably, the second injection unit is configured to inject liquid silicone rubber plastic, especially Elastosil plastic and / or Silopren plastic, as a second injection-molded filler component. Such plastics have self-adhesive properties and therefore can be easily and seamlessly cross-linked around the bipolar plate. This eliminates the need for the complex fabrication of seals and subsequent placement into the slots of the bipolar plate, as is required in the prior art. Furthermore, leakage is avoided through seamless material-locking cross-linking.

[0025] To seal the first and second cavities relative to the environment at the injection position of the injection molding apparatus and to prevent the initially liquid first or second injectable filler components from flowing out, the first injection molding mold component preferably has a first immersion surface, and the second injection molding mold component preferably has a second immersion surface. Here, the first and second immersion surfaces can slide parallel to each other and / or in direct contact with each other.

[0026] In the prior art, channels on the sides of bipolar plates are formed through laborious and complex subsequent processes (e.g., etching, radiation, surface roughening, or by applying polymer powder). To enable the fabrication of channels in a simple and cost-effective manner, the inner surfaces of the first and / or second injection molding die components are preferably at least partially contoured for imprinting fine structures, particularly channel structures. Preferably, the contoured portion is formed by a cut-out and / or a raised portion.

[0027] According to a second aspect of the invention, an injection molding method is provided for manufacturing a bipolar plate and a sealing portion surrounding the bipolar plate using an injection molding apparatus according to the invention.

[0028] The injection molding embossing method includes the following steps: - The first and second injection molding die components are moved relative to each other from their starting positions to the injection position of the injection molding device, such that the first and second injection molding die components form a first cavity for manufacturing a bipolar plate and a second cavity for manufacturing a sealing portion surrounding the bipolar plate. - Heat the first and second injection molding die components to a temperature between 160°C and 200°C, especially to a temperature of 180°C. - Injecting the first injection-molded filler component, especially the bulk-formed composite plastic, into the first cavity. - Move the first and second injection molding die components relative to each other from the injection position to the closed position of the injection molding device. - In the first cavity, the first injection-molded filler component is imprinted and cured into a bipolar plate with a channel structure. - Move the first injection molding die component and the second injection molding die component from their closed positions to their starting positions, with them facing away from each other. - Transfer the cured bipolar plate from the first cavity to the second cavity. - Move the first and second injection molding die components relative to each other from the starting position to the injection position. - The filler component, especially liquid silicone rubber plastic, that can be injection molded is injected into the second cavity. - To move the first and second injection molding die components relative to each other from the injection position to the closed position. - In the second cavity, the second injection-molded filler component material is interlocked and crosslinked to form a surrounding, seamless, and adherent seal around the bipolar plate. - To move the first injection molding die component and the second injection molding die component away from each other from the closed position to the starting position, and - Remove the bipolar plate with a surrounding, seamless, and attached seal from the second cavity.

[0029] The advantages of the injection molding apparatus for manufacturing bipolar plates and the sealing portion surrounding the bipolar plates, as described in detail in the first aspect of the invention, are equally applicable to the injection molding method for manufacturing bipolar plates and the sealing portion surrounding the bipolar plates by means of the injection molding apparatus according to the second aspect of the invention.

[0030] Other advantages, features, and details of the invention will become apparent from the following description, in which embodiments of the invention are described in detail with reference to the accompanying drawings. Herein, the features mentioned in the claims and in the description may be important to the invention individually or in any combination. Attached Figure Description

[0031] The invention will be explained in more detail below with the aid of the accompanying drawings. The following are schematic illustrations: Figure 1 According to an embodiment of the present invention, an injection molding embossing device at the injection position; Figure 2 According to an embodiment of the present invention, an injection molding embossing device for manufacturing a first component in a closed position; Figure 3 According to an embodiment of the present invention, an injection molding embossing device for manufacturing a second component in a closed position; and Figure 4 A block diagram illustrating the method steps for manufacturing the first and second components according to an embodiment of the present invention. Detailed Implementation

[0032] Figure 1 An injection molding embossing apparatus 10 according to the present invention is shown, which has a first injection molding embossing mold component 40, a second injection molding embossing mold component 50, a first injection unit 61 and a second injection unit 71.

[0033] The first injection molding die component 40 and the second injection molding die component 50 are movable relative to each other, forming a first cavity 60 for manufacturing the bipolar plate 20 and a second cavity 70 for manufacturing the sealing portion 30 surrounding the bipolar plate 20. The first cavity 60 is plate-shaped. The shape of the second cavity 70 is larger than that of the first cavity 60, such that the shape of the second cavity 70 at least has the shape of the first cavity 60, and the shape of the first cavity 60 is further extended by a surrounding frame, especially a T-shaped frame.

[0034] The first injection unit 61 is connected to the first flat cavity 60 via at least one first injection channel 63 for injecting a first injection-moldable filler component 62. The second injection unit 71 is connected to the second surrounding cavity 70 via at least one second injection channel 73 for injecting a second injection-moldable filler component 72.

[0035] The first injection molding die component 40 and the second injection molding die component 50 are positioned in the injection position of the injection molding apparatus 10. In the injection position, a first injection molding filler component 62 or a second injection molding filler component 72 is injected into the first cavity 60 or the second cavity 70.

[0036] The first injection molding die component 40 has first immersion surfaces 64 and 65. The second injection molding die component 50 has second immersion surfaces 74 and 75. The first immersion surfaces 64 and 65 and the second immersion surfaces 74 and 75 can slide parallel to each other and / or in direct contact with each other.

[0037] The first cavity 60 and the second cavity 70 can be reduced or enlarged by the relative sliding of the first impregnation surfaces 64 and 65 and the second impregnation surfaces 74 and 75 relative to each other.

[0038] At the injection site, the first cavity 60 and the second cavity 70 have a larger volume than the final manufactured bipolar plate or seal. This allows for the injection of the first injection-moldable filler component 62 or the second injection-moldable filler component 72 with lower pressure requirements and achieves imprinting with less deformation.

[0039] The starting position represents the open position of the injection molding embossing device 10, in which the first immersion surfaces 64, 65 and the second immersion surfaces 74, 75 slide parallel to each other or are relatively far apart from each other and do not contact each other.

[0040] In the injection position, the first impregnation surfaces 64, 65 and the second impregnation surfaces 74, 75 are in direct contact with each other in the front region, such that the first cavity 60 and the second cavity 70 are still sealed and closed.

[0041] The first cavity 60 and the second cavity 70 can be partially or completely filled. Cavity restrictors can be provided for this purpose.

[0042] Figure 2 An injection molding apparatus 10 according to the invention is shown for manufacturing a first component, particularly a thin structured bipolar plate 20.

[0043] In order to compress and imprint the filler component 62 for the first injection molding, the first injection molding die component 40 and the second injection molding die component 50 are brought from the injection position to the closed position by the closing force of the injection molding device 10. Here, the first impregnated surfaces 64, 65 and the second impregnated surfaces 74, 65 move relative to each other or travel toward each other, wherein these impregnated surfaces are in direct contact with each other throughout the closing movement.

[0044] The force used to open and close the injection molding embossing device 10, especially the force used to move the first injection molding embossing mold component 40 and the second injection molding embossing mold component 50 relative to each other, can be caused by pneumatic, hydraulic and / or electric actuators.

[0045] The first injection molding filler component 62 is a bulk molding composite plastic, especially a long glass fiber and / or carbon fiber reinforced plastic, which was previously injected into the first cavity 60 in a liquid state at the injection position via a first injection unit 61 through at least one first injection channel 63.

[0046] Bipolar plates typically have fine structures on one or both sides, particularly fine open and / or fine closed channels, along which the reactive fluid can flow or within the channels. Channels are especially embedded on the electrode-facing side of the bipolar plate. The finer the channel structure, the higher the efficiency of the bipolar plate. Furthermore, the fine channel structure prevents the reactive fluid from adhering to the surface of the bipolar plate.

[0047] To enable the simultaneous fabrication and imprinting of the bipolar plate 20 along with the channel in a single step, the first injection molding die component 40 has an inner surface 66, and the second injection molding die component 50 has an inner surface 76, both of which are locally contoured. The contoured portions are formed by cutouts and raised portions to achieve the imprinting of fine structures, particularly channel structures. Here, the cutouts and raised portions may, for example, have an average depth T, where 5 nm ≤ T ≤ 1 pm.

[0048] The first injection-molded filler component 62 is compressed and imprinted into a bipolar plate 20 in the first cavity 60. In particular, conformal temperature control or mold-fit temperature control is performed in the first flat cavity 60, also known as "conformal cooling." Here, the first injection-molded filler component 62 is conformally temperature controlled as closely as possible to achieve a shorter cycle time while maintaining higher quality. Through conformal temperature control, especially after curing, the temperature resistance and strength of the bipolar plate 20 are significantly improved.

[0049] In order to achieve the liquefaction of the first injection molding filler component 62 and the second injection molding filler component 72, and subsequent conformal temperature control, the first injection molding mold component 40 and the second injection molding mold component 50 can be heated to a temperature between 160°C and 200°C, and particularly to a temperature of 180°C. Heating of the first injection molding mold component 40 and the second injection molding mold component 50 can be performed, for example, by a heating device, contact heating, hot air, laser radiation, infrared radiation, or ultrasound.

[0050] The first injection molding die component 40 and the second injection molding die component 50 may have cooling channels for heat dissipation or be connected to a cooling system, thereby accelerating the curing of the injection molding filler components 62, 72.

[0051] It is conceivable that the liquefaction of the first injection molding filler component 62 and the second injection molding filler component 72 is carried out externally, rather than by heating the first injection molding mold component 40 and the second injection molding mold component 50.

[0052] Figure 3 An injection molding apparatus 10 for manufacturing a second component according to the invention is shown, in particular a seamless and attached sealing portion 30 surrounding the bipolar plate 20.

[0053] After the first injection molding filler component 62 is temperature-cured into a bipolar plate 20 in the first cavity 60, the injection molding device 10 is reopened. Here, the bipolar plate 20 is removed from the first cavity 60 and transferred to the second cavity 70. Subsequently, the first injection molding mold component 40 and the second injection molding mold component 50 are brought into the injection position to inject the second injection molding filler component 72.

[0054] The transfer of the bipolar plate 20 can be performed, for example, by means of a gripping device comprising automated robotic technology with a flexible gripping arm, capable of holding the bipolar plate 20 or moving it along the X, Y, and Z directions. For this purpose, the gripping device can be connected to a control device having imprinting software, by means of which the gripping device can be programmed. Thus, the cured bipolar plate can be quickly and easily transferred from the first cavity 60 to the second cavity 70, and then removed from the second cavity 70 after completion.

[0055] The second injection molding filler component 72 is liquid silicone rubber plastic, especially Elastosil plastic and / or Silopren plastic, which is injected into the second cavity 70 in a liquid state through the second injection unit 71 via at least one second injection channel 73.

[0056] After injection, in order to compress the filler component 72 of the second injection molding embossing, the first injection molding die component 40 and the second injection molding die component 50 are brought from the injection position into the closed position by the closing force of the injection molding device 10. Here, the first impregnated surfaces 64, 65 and the second impregnated surfaces 74, 65 move relative to each other or travel towards each other, wherein these impregnated surfaces are in direct contact with each other throughout the closing movement.

[0057] The first injection-molded filler component 62 and the second injection-molded filler component 72 crosslink at the same temperature of 180°C. Due to the active surfaces of the two filler components 62 and 72, they form a material-locked connection, thereby pressing the second injection-molded filler component 72 into a surrounding, seamless, and adherent seal 30 around the bipolar plate. Through the material-locked connection of the first injection-molded filler component 62 and the second injection-molded filler component 72, no seam is formed, thus preventing leakage. The surrounding and adherent seal 30 can be considered as a sealing lip structure, yet without seams, thus ensuring a tight seal even under low contact pressure. Therefore, the diameter of the seal can be designed to be correspondingly thin.

[0058] In other words, the first injection-molded filler component 62, particularly a bulk-formed composite plastic, and the second injection-molded filler component 72, particularly liquid silicone rubber, are melted by the first injection molding die component 40 and the second injection molding die component 50 heated to 180°C and injected into the first cavity 60 or the second cavity 70. Under pressure, they are compressed and imprinted, causing the first injection-molded filler component 62 and the second injection-molded filler component 72 to crosslink in a locked manner, wherein no seam is formed. Here, the material locking and crosslinking occurs particularly at the heated boundary layer or surface of the first injection-molded filler component 62 and the second injection-molded filler component 72.

[0059] Figure 4 A block diagram is shown to illustrate the steps of manufacturing a bipolar plate 20 and a sealing portion surrounding the bipolar plate using an injection molding apparatus 10 according to the invention.

[0060] In the first step S1, the first injection molding die component 40 and the second injection molding die component 50 are moved from the starting position of the injection molding device 10 relative to each other to the injection position, such that the first injection molding die component 40 and the second injection molding die component 50 form a first cavity 60 for manufacturing the bipolar plate 20 and a second cavity 70 for manufacturing the sealing portion 30 surrounding the bipolar plate 20. In the second step S2, the first injection molding die component 40 and the second injection molding die component 50 are heated to a temperature between 160°C and 200°C, particularly to a temperature of 180°C. After the first injection molding die component 40 and the second injection molding die component 50 are heated, in the third step S3, a first injection-moldable filler component 62, particularly a bulk molding composite plastic, is injected into the first cavity 60. Subsequently, in the third step S4, the first injection molding die component 40 and the second injection molding die component 50 are moved from the injection position relative to each other to the closed position. In the closed position, the first injection-molded filler component 62 is imprinted and cured (S5) in the first cavity 60 to form a bipolar plate 20 with a channel structure. After the bipolar plate 20 is cured, the first injection molding die component 40 and the second injection molding die component 50 move from the closed position relative to each other to the starting position to open (S6) the injection molding device 10. In the open position of the injection molding device 10, the bipolar plate 20 is transferred (S7) from the first cavity 60 to the second cavity 70. Subsequently, the first injection molding die component 40 and the second injection molding die component 50 move (S8) from the starting position relative to each other to the injection position. In the injection position, in the ninth step (S9), the second injection-molded filler component 72, in particular liquid silicone rubber plastic, is injected into the second cavity 70. Subsequently, in the tenth step (S10), the first injection molding die component 40 and the second injection molding die component 50 move from the injection position relative to each other to the closed position. In the closed position, the second injection-molded filler component 72 in the second cavity 70 is cross-linked S11 by material locking to form a surrounding, seamless and attached seal 30 around the bipolar plate 20.

[0061] Subsequently, the first injection molding die component 40 and the second injection molding die component 50 are moved from their closed positions relative to each other to their starting positions to open the injection molding device 10 in step S12. In the final step S13, the bipolar plate 20 with the surrounding, seamless, and attached sealing portion 30 is removed from the second cavity 70.

Claims

1. An injection molding apparatus (10) for manufacturing a bipolar plate (20) and a sealing portion (30) surrounding the bipolar plate (20), the injection apparatus (10) having a first injection molding die component (40) and a second injection molding die component (50), wherein, The first injection molding die component (40) and the second injection molding die component (50) are movable relative to each other, wherein the first injection molding die component (40) and the second injection molding die component (50) form a first cavity (60) for manufacturing the bipolar plate (20) and a second cavity (70) for manufacturing the sealing portion (30) surrounding the bipolar plate (20) at the injection position of the injection molding device (10).

2. The injection molding embossing device (10) according to claim 1. Its features are, The first cavity (60) has the shape of a thin cuboid, especially a thin plate.

3. The injection molding embossing device (10) according to claim 1 or 2. Its features are, The shape of the second cavity (70) is larger than that of the first cavity (60), such that the shape of the second cavity (70) has at least the shape of the first cavity (60), and additionally the shape of the first cavity (60) is extended by a surrounding frame, especially a T-shaped frame.

4. The injection molding embossing apparatus (10) according to any one of the preceding claims. Its features are, The first injection molding die component (40) and the second injection molding die component (50) can be heated to a temperature between 160°C and 200°C, especially to a temperature of 180°C.

5. The injection molding embossing apparatus (10) according to any one of the preceding claims. Its features are, The injection molding embossing device (10) has a first injection unit (61) for injecting a first injection-embossable filler component (62), wherein the first injection unit (61) is connected to the first cavity (60) through at least one first injection channel (63).

6. The injection molding embossing device (10) according to claim 5. Its features are, The first injection unit (61) is configured to inject bulk molding composite plastic, especially long glass fiber and / or carbon fiber reinforced plastic, as a first injection molding filler component (62).

7. The injection molding embossing apparatus (10) according to any one of the preceding claims. Its features are, The injection molding embossing device (10) has a second injection unit (71) for injecting a second injection-embossable filler component (72), wherein the second injection unit (71) is connected to the surrounding second cavity (70) via at least one second injection channel (73).

8. The injection molding embossing device (10) according to claim 7. Its features are, The second injection unit (71) is configured to inject liquid silicone rubber plastic, especially Elastosil plastic and / or Silopren plastic as a second filler component (72) that can be injection molded.

9. The injection molding embossing apparatus (10) according to any one of the preceding claims. Its features are, The first injection molding die component (40) has a first immersion surface (64, 65), and the second injection molding die component (50) has a second immersion surface (74, 65), wherein the first immersion surface (64, 65) and the second immersion surface (74, 75) can slide relative to each other in parallel and / or in direct contact with each other.

10. The injection molding embossing apparatus (10) according to any one of the preceding claims. Its features are, The inner surface (66) of the first injection molding die component (40) and / or the inner surface (76) of the second injection molding die component (50) are at least partially profiled for imprinting fine structures, especially channel structures.

11. The injection molding embossing apparatus (10) according to claim 10. Its features are, The contouring is formed by the excavation and / or the raised portion.

12. An injection molding method (100) for manufacturing a bipolar plate (20) and a sealing portion (30) surrounding said bipolar plate (20) using an injection molding apparatus (10) according to any one of claims 1 to 11, wherein, The injection molding embossing method (100) includes the following steps: - Move the first injection molding die component (40) and the second injection molding die component (50) relative to each other from the starting position (S1) to the injection position of the injection molding device (10), such that the first injection molding die component (40) and the second injection molding die component (50) form a first cavity (60) for manufacturing the bipolar plate (20) and a second cavity (70) for manufacturing the sealing portion (30) surrounding the bipolar plate (20). - The first injection molding die component (40) and the second injection molding die component (50) are heated (S2) to a temperature between 160°C and 200°C, especially to a temperature of 180°C. - The first injection-molded filler component (62), especially the bulk molding composite plastic, is injected (S3) into the first cavity (60). - Move the first injection molding die component (40) and the second injection molding die component (50) relative to each other from the injection position (S4) to the closed position of the injection molding device (10). - The first injection-molded filler component (62) is imprinted (S5) and cured into a bipolar plate (20) with a channel structure in the first cavity (60). - Move the first injection molding die component (40) and the second injection molding die component (50) away from each other from the closed position to the starting position (S6). - The cured bipolar plate (20) is transferred (S7) from the first cavity (60) to the second cavity (70). - Move the first injection molding die component (40) and the second injection molding die component (50) relative to each other from the starting position (S8) to the injection position. - The second injection-molded filler component (62), in particular the liquid silicone rubber plastic, is injected (S9) into the second cavity (70). - The first injection molding die component (40) and the second injection molding die component (50) are moved relative to each other from the injection position (S10) to the closed position. - In the second cavity (70), the second injection-molded filler component (62) material is interlocked and crosslinked to form a surrounding, seamless and attached seal (30) around the bipolar plate (20). - Move the first injection molding die component (40) and the second injection molding die component (50) away from each other from the closed position to the starting position (S12), and - Take out (13) the bipolar plate (20) with the surrounding, seamless and attached seal (30) from the second cavity (70).

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