Method for manufacturing gasket and mold

Abstract

This application discloses a method and mold for manufacturing a gasket. The method for manufacturing a gasket includes the following steps: S1: preparing raw rubber and a first member, the first member including a base and an adhesive coating layer attached to an upper surface of the base, the material of the base including a lubricating material; S2: placing the first member in an inner cavity of a molding die, the molding die including an upper die, a first body surface of the upper die being arc-shaped, at least a portion of the first body surface forming at least a portion of an upper wall surface of the inner cavity of the molding die, the molding die further including a lower die, a second body surface of the lower die being arc-shaped. S2: The first member is shaped like a gasket, at least a portion of the second main body surface constitutes at least a portion of the lower wall surface of the inner cavity of the molding die, and the adhesive coating layer of the first member is directed toward the upper die; S3: Raw rubber is placed in the inner cavity of the molding die; S4: The raw rubber placed in the inner cavity of the molding die is vulcanized to form the raw rubber integrally with the first member; and the present application further provides a die that can be used as a carrier for molding a gasket that combines sealing properties with reduced friction against moving members.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application filed with the China National Intellectual Property Administration on March 24, 2021, with the application number 202110314327.6 and the title of the invention "Method for Manufacturing Gasket and Mold", and all its contents are incorporated herein by reference. [Technical Field]

[0002] This application relates to the technical field of seal manufacturing, specifically to a method for manufacturing a gasket and a mold.

Background Art

[0003] Gaskets are widely used as seals. The materials of gaskets include rubber. Usually, the sealing effect of gaskets mainly utilizes the elasticity of rubber. In some application scenarios, a moving member may move relative to the gasket. Thus, friction may occur between the surface of the gasket in contact with the moving member, which may in turn affect the movement of the moving member. Therefore, how to manufacture a seal that can achieve both sealing performance and reduction of frictional force on the moving member, and the mold corresponding to this seal, are technical problems to be considered.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The object of this application is to provide a method for manufacturing a gasket that can manufacture a gasket capable of achieving both sealing performance and reduction of frictional force on the moving member.

[0005] The object of this application is further to provide a mold used as a carrier for manufacturing the above-mentioned seal.

Means for Solving the Problems

[0006] To achieve the above object, an embodiment of this application adopts the following technical solutions. A method for manufacturing a gasket, comprising the following steps, namely, S1: Prepare a raw rubber and a first member, the first member including a base body and an adhesive coating layer attached to the upper surface of the base body, the material of the base body including a lubricating material, S2: Place the first member in the inner cavity of a molding die, the molding die including an upper die having a first main body surface in an arc shape, at least a part of the first main body surface constituting at least a part of the upper wall surface of the inner cavity of the molding die, the molding die further including a lower die having a second main body surface in an arc shape, at least a part of the second main body surface constituting at least a part of the lower wall surface of the inner cavity of the molding die, and the adhesive coating layer of the first member being directed toward the upper die of the molding die, S3: Place the raw rubber in the inner cavity of the molding die, S4: Vulcanize the raw rubber placed in the inner cavity of the molding die to integrally form the raw rubber with the first member.

[0007] A die, used as a carrier for manufacturing the seal, the die including a lower die and an upper die, the lower die and the upper die being clamped to form at least one inner cavity, the inner cavity including a storage cavity for storing raw materials necessary for molding the gasket, the upper die having a first main body surface in an arc shape, at least a part of the first main body surface constituting at least a part of the upper wall surface of the inner cavity of the die, the die further having a lower die, the lower die having a second main body surface in an arc shape, at least a part of the second main body surface constituting at least a part of the lower wall surface of the inner cavity of the die.

[0008] In the method for manufacturing a gasket disclosed in the present application, according to the above form, on the one hand, the vulcanized raw rubber has elasticity, and thus the gasket can achieve a sealing effect. On the other hand, since the material of the base body in the first member includes a lubricating material, it is thus advantageous for reducing the frictional force on the moving member. Therefore, by the above method for manufacturing a gasket, a gasket that can achieve both sealing performance and reduction of the frictional force on the moving member can be manufactured.

[0009] In the mold disclosed in this application, the upper mold of the mold has a first main body surface in an arc shape, and at least a part of the first main body surface constitutes at least a part of the upper wall surface of the inner cavity of the mold. The mold further includes a lower mold. The lower mold has a second main body surface in an arc shape, and at least a part of the second main body surface constitutes at least a part of the lower wall surface of the inner cavity of the mold. On the one hand, this mold can be used as a carrier for manufacturing the above gasket. On the other hand, since the main body of the gasket manufactured by this mold is in an arc shape, the consistency between the manufactured seal and the seal in the actual use state can be improved.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

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Figure 8

Modes for Carrying Out the Invention

[0011] Hereinafter, this application will be further described by combining the drawings and specific examples. Hereinafter, specific embodiments of the present application will be described in detail with reference to the drawings. First, it should be noted that the orientation terms such as up, down, left, right, front, back, inside, outside, top, bottom, etc., which are mentioned or may be mentioned in this specification, are defined with respect to the structures shown in the corresponding drawings. Since these are relative concepts, they may change according to their different positions and different usage states. Therefore, these or other orientation terms should not be construed as limiting terms.

[0012] Referring to FIG. 1, FIG. 1 is a first embodiment of a method for manufacturing a gasket, and the first embodiment of the gasket manufacturing method will be introduced below.

[0013] Referring to FIG. 1, the method for manufacturing a gasket includes the following steps, that is, S1: Prepare raw rubber and a first member. The first member includes a base body and an adhesive coating layer attached to the upper surface of the base body. The material of the base body includes a lubricating material. In this embodiment, the base body may be a plastic layer, and the lubricating material may mainly be polytetrafluoroethylene (PTFE). Of course, as another embodiment, the lubricating material may mainly be a copolymer (PFA) of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene. S2: Place the first member in the inner cavity of the molding die. The molding die includes an upper die having a first main body surface in an arc shape, and at least a part of the first main body surface constitutes the upper wall surface of the inner cavity of the molding die. The molding die further includes a lower die having a second main body surface in an arc shape, and at least a part of the second main body surface constitutes the lower wall surface of the inner cavity of the molding die. The lower surface of the base body of the first member contacts the second main body surface, and the adhesive coating layer of the first member faces the upper die, that is, the upper surface of the adhesive coating layer of the first member is used as the bonding surface. In this embodiment, the lower surface of the base body of the first member is for contacting an external moving member. S3: Place raw rubber of a preset specification in the inner cavity of the molding die. The raw rubber placed in the inner cavity of the molding die contacts the adhesive coating layer of the first member. S4: Vulcanize the raw rubber placed in the inner cavity of the molding die. The vulcanized raw rubber contacts the second main body surface, and the vulcanized raw rubber is integrally adhered to the adhesive coating layer of the first member.

[0014] In the above form, on the one hand, the vulcanized raw rubber has elasticity, and thus the gasket can achieve a sealing effect. On the other hand, since the material of the base in the first member contains a lubricating material, it is thus advantageous for reducing the frictional force on the moving member. Therefore, by the above method for manufacturing a gasket, a gasket that can achieve both sealing performance and reduction of the frictional force on the moving member can be manufactured.

[0015] The above steps will be introduced in more detail below.

[0016] Referring to FIG. 1, in this embodiment, the first member has flexibility, and the thickness of the first member is 0.2 mm or more and 0.6 mm or less. For example, the thickness of the first member may be 0.4 mm or 0.5 mm, etc. In this embodiment, if the thickness of the first member is too thick, it may affect the sealing. If the thickness of the first member is too thin, in step S4, it may be prone to wrinkling and deformation. Also, it should be noted here that the numerical values described in this application may be accurate numerical values or rounded numerical values. Also, the corresponding cover area of the raw rubber on the first member is not more than the surface area of the adhesive coating layer of the first member.

[0017] Referring to FIG. 1, in this embodiment, in step S1, the material of the base contains polytetrafluoroethylene, and the first member has a flat shape.

[0018] In step S1, before applying the adhesive to the substrate of the first member, surface treatment is performed on the surface of the substrate of the first member for applying the adhesive. Specifically, it may be means such as naphthalene sodium treatment or polishing. Thus, it is advantageous for improving the adhesive strength between the adhesive coating layer and the substrate of the first member. The adhesive coating layer can include an undercoat layer and a topcoat layer. First, the undercoat layer is applied to the upper surface of the substrate. After the undercoat layer is dried, the topcoat layer is applied to the surface of the undercoat layer and the topcoat layer is dried. Here, the "drying" may be natural air drying or, for example, auxiliary drying such as stoving or air drying. In this embodiment, by applying the undercoat layer, the adhesive and the substrate of the first member can be surely adhered, and by applying the topcoat layer, the dried undercoat layer and the vulcanized rubber can be surely adhered. In this embodiment, the undercoat layer and the topcoat layer are adhesives of different model numbers. Of course, as another embodiment, only one layer of adhesive may be applied to the upper surface of the substrate. In this case, it corresponds to only one model number of adhesive.

[0019] In step S3, the method for realizing placing the raw rubber of a preset specification in the inner cavity of the molding die includes the following two means. That is, the first means is to put the raw rubber of a preset specification into the trough of the molding die, and the pressure column of the vulcanizer pushes the raw rubber in the trough into the supply port of the inner cavity of the molding die. Further, the raw rubber is pushed into the inner cavity of the molding die through the supply port of the molding die. In this embodiment, before putting the raw rubber of a preset specification into the trough of the molding die, the trough of the molding die has a certain temperature, and this temperature of the trough is below the first preset temperature in step S4. The corresponding pressure for pushing the raw rubber into the inner cavity of the molding die is 8 MPa or more and 10 MPa or less.

[0020] The second means is to put the raw rubber into the cylinder of an injection molding machine, preheat the raw rubber in the cylinder of the injection molding machine to a second preset temperature which is lower than the first preset temperature, and then the screw of the injection molding machine injects the raw rubber in the cylinder of the injection molding machine into the gate of the molding die, and further injects the raw rubber into the inner cavity of the molding die through the gate of the molding die. When the weight of the raw rubber injected into the inner cavity of the molding die reaches the preset weight, the injection is stopped. Of course, other means may also be used to realize placing the raw rubber of the preset specification in the inner cavity of the molding die.

[0021] Also, in the above two means, the raw rubber of the preset specification refers to the raw rubber of the preset weight. Of course, as other embodiments, the raw rubber of the preset specification may refer to the raw rubber of the preset volume or the preset capacity or the preset size.

[0022] In step S4, the corresponding vulcanization time is defined as the first preset time, the corresponding preset temperature is defined as the first preset temperature, the first preset time is 3 min or more and 5 min or less, and the first preset temperature is 170 °C or more and 200 °C or less.

[0023] In step S4, to keep the vulcanization temperature of the raw rubber placed in the inner cavity of the molding die and the first member at the first preset temperature includes the following three means. The first means is to heat the raw rubber in the inner cavity of the molding die and the first member until they reach the first preset temperature. The second means is that before placing the raw rubber and the first member in the molding die, the mold cavity of the molding die has already reached the first preset temperature. The third means is that before placing the raw rubber and the first member in the molding die, the mold cavity of the molding die has already had a certain temperature lower than the first preset temperature, and after placing the raw rubber and the first member in the mold cavity of the molding die, heat the raw rubber in the inner cavity of the molding die and the first member until they reach the first preset temperature.

[0024] In step S4, it further includes discharging the gas in the inner cavity of the molding die at least once, thus easily preventing blow holes from occurring in the finally manufactured gasket. The specific operations can include the following several means. The first means is to open the upper die and / or the lower die of the molding die, so that there is a gap between the upper die and the lower die of the molding die, and the gas in the inner cavity of the molding die is discharged from the gap between the upper die and the lower die. After a preset time has elapsed, the upper die and the lower die of the mold are closed. Here, the number of times of opening the upper die and / or the lower die of the molding die for exhaust may be more than once. When the number of times of opening the upper die and / or the lower die of the molding die for exhaust is more than once, the number of times can be set according to the time or the adhesive injection amount. The second means is to add an exhaust valve externally and provide an exhaust hole in the molding die. The exhaust hole and the exhaust valve are communicated, and the inner cavity of the molding die is exhausted by the exhaust valve. In this way, it is not necessary to open the upper die and / or the lower die of the molding die, which is advantageous for saving the manufacturing time. The third means is to evacuate the inner cavity of the molding die.

[0025] Referring to FIG. 2, FIG. 2 is a second embodiment of the gasket manufacturing method, and the second embodiment of the gasket manufacturing method will be introduced in detail below.

[0026] Referring to FIG. 2, in this embodiment, the gasket manufacturing method includes steps S1 to S5. Since the first embodiment can be referred to for steps S1 to S4 among them, they will not be described again here.

[0027] Referring to FIG. 2, in this embodiment, the gasket manufacturing method further includes the following steps S5: Define the integrally adhered and vulcanized raw rubber and the first member as an intermediate body, place the cooled intermediate body in a container, heat the intermediate body placed in the container, and maintain the intermediate body placed in the container at a third preset temperature within a second preset time to secondary vulcanize the intermediate body. The third preset temperature is lower than the first preset temperature. Here, cooling the intermediate body is advantageous for relatively stabilizing the molecular motion of the rubber. The cooling means here may be natural air cooling or other means such as air cooling or water cooling.

[0028] In the above step S5, the second preset time is 2 h or more and 4 h or less, and the third preset temperature is 140 °C or more and 160 °C or less, which is advantageous for further improving the mechanical properties of the rubber by secondary vulcanization. Of course, as another embodiment, secondary vulcanization may not be performed. In this case, parameters such as the vulcanization time and vulcanization temperature of the primary vulcanization can be adjusted as appropriate. Referring to FIG. 3, FIG. 3 is a third embodiment of the gasket manufacturing method, and the third embodiment of the gasket manufacturing method will be introduced in detail below.

[0029] Referring to FIG. 3, in this embodiment, the gasket manufacturing method includes steps S1 to S4, step S6, and step S7. Since the first embodiment can be referred to for steps S1 to S4 among them, they will not be described again here.

[0030] Referring to FIG. 3, in this embodiment, the gasket manufacturing method further includes the following steps: S6: Remove the excess end material of the gasket. S7: Punch holes at preset positions of the gasket. In this embodiment, the gasket includes a plurality of through holes. Along the thickness direction of the gasket, the through holes are provided to penetrate. By punching holes at preset positions of the gasket, through holes are formed.

[0031] In this embodiment, process S6 is performed first, and then process S7 is performed. Of course, as another embodiment, process S7 may be performed first, and then process S6 may be performed. Also, in this embodiment, the method for manufacturing the gasket includes two processes, S6 and S7. Of course, as another embodiment, it is also possible to include only one of process S6 and process S7.

[0032] Also, before performing the above process S6, the secondary-vulcanized intermediate may be cooled. This is advantageous for relatively stabilizing the molecular motion of the rubber. Here, the cooling means may be natural air cooling, or other means such as air cooling or water cooling. Of course, as another embodiment, cooling may be performed after process S6 or process S7.

[0033] Referring to FIG. 4, FIG. 4 is a fourth embodiment of the method for manufacturing a gasket. The fourth embodiment of the method for manufacturing a gasket will be introduced in detail below.

[0034] Referring to FIG. 4, in this embodiment, the method for manufacturing a gasket includes processes S1 to S7. Since reference can be made to the second embodiment for processes S1 to S5, they will not be described again here.

[0035] Referring to FIG. 4, in this embodiment, the method for manufacturing a gasket further includes the following processes: S6: Removing the excess end material of the gasket. S7: Drilling at a preset position of the gasket. In this embodiment, the gasket includes a plurality of through holes. Along the thickness direction of the gasket, the through holes are provided to penetrate. By drilling at a preset position of the gasket, the through holes are formed.

[0036] Specifically, in process S6, the gasket is placed in a press device. Further, the rubber layer of the gasket is supported by the press lower die and contacts the press lower die, and the first member faces the press upper die. By the pressing action from the press upper die toward the press lower die, through holes are formed at a preset position of the gasket, and the periphery of the through holes of the formed gasket is in a closed state.

[0037] In this embodiment, step S6 is performed first, and then step S7 is performed. Of course, as another embodiment, step S7 may be performed first, and then step S6 may be performed. Further, in this embodiment, the manufacturing method of the gasket includes two steps, S6 and S7. Of course, as another embodiment, it is also possible to include only one of step S6 and step S7.

[0038] Also, before performing the above step S6, the secondarily vulcanized intermediate may be cooled. In this way, it is advantageous to relatively stabilize the molecular motion of the rubber. The cooling means here may be natural air cooling, or other means such as air cooling or water cooling. Of course, as another embodiment, it may be cooled after step S6 or step S7.

[0039] Referring to FIG. 5, FIG. 5 shows a schematic diagram of an actual object corresponding to a fourth embodiment of the manufacturing method of the gasket.

[0040] Referring to FIG. 5, the first product 1 that has gone through steps S1 to S5 includes a first member 11 adhered to the raw rubber and a raw rubber 12 that has been vulcanized and molded. Of course, in the manufacturing methods of the gasket in the first embodiment and the third embodiment, the first product 1 may be produced through steps S1 to S4. The product produced after the first product 1 has gone through the above step S6 is the second product 2, and the product produced after the second product 2 has gone through the above step S7 is the final gasket 3.

[0041] Referring to FIG. 6, the lower surface of the first member 11 includes a main body surface 111 and a connection surface 112. The connection surface 112 is connected to the corresponding side wall of the through hole 30 in the first member. The connection surface 112 is inclined. Along the thickness direction of the gasket 3, the corresponding side wall of the through hole 112 in the first member 11 is lower than the main body surface 111. In this way, it is advantageous to prevent scratches from occurring on the peripheral wall of the through hole 30 when the moving member moves and further affecting the movement of the moving member. In this embodiment, the connection surface 112 is formed by a molding die in step S4.

[0042] This application further discloses a mold used as a carrier for process S2, process G1, process S3, process G1', and process S4. Referring to FIGS. 7 and 8, the mold includes a lower mold 4 and an upper mold 5. The lower mold 4 and the upper mold 5 are clamped to form at least one inner cavity. The inner cavity includes a storage cavity for storing raw materials necessary for molding the gasket. The upper mold 5 has a first main body surface 51 in an arc shape, and at least a part of the first main body surface 51 constitutes at least a part of the upper wall surface of the inner cavity of the mold. The mold further has a lower mold 5. The lower mold 4 has a second main body surface 41 in an arc shape, and at least a part of the second main body surface 41 constitutes at least a part of the lower wall surface of the inner cavity of the mold. Herein, the "arc shape" described refers to being substantially in an arc shape. With the above configuration, on the one hand, this mold can be used as a carrier for manufacturing the above gasket. On the other hand, since the main body of the gasket manufactured by this mold is in an arc shape, the consistency between the manufactured seal and the seal in the actual use state can be improved.

[0043] Referring to FIG. 7, the upper mold 5 further includes a plurality of first protrusions 52 and grooves 50. Of course, as another embodiment, there may be only one second protrusion and groove 50 or two or more other numbers. The first protrusion 51 is provided to protrude from the first main body surface 51, and the groove 50 is provided to be recessed from the first main body surface 51. The groove 50 is located outside the first protrusion 51. The first protrusion 52 has a first inclined surface 521 located on the circumferential side of the first protrusion 51. The first inclined surface 521 connects the top surface of the first protrusion 52 and the root of the first protrusion 52. The top surface of the first protrusion 52 is orthogonally projected onto the root of the first protrusion 52, and the projection of the top surface of the first protrusion 52 is located inside the root of the first protrusion 52. In this embodiment, the groove 50 includes a first groove 501 provided along the longitudinal direction of the upper mold 5 and a second groove 502 provided along the width direction of the upper mold 5. The first groove 501 and the second groove 502 are provided in a vertical and horizontal cross pattern. In this embodiment, around the first protrusion 52, a part of the first groove 501 and a part of the second groove 502 are provided. The first groove 501 and the second groove 502 are provided to surround the first protrusion 52.

[0044] Referring to FIG. 8, the lower mold 4 further includes a plurality of second protrusions 42. Of course, as another embodiment, there may be only one second protrusion or two or more other numbers. The second protrusion 42 is provided to protrude from the second main body surface 41. The second protrusion 42 has a second inclined surface 421 located on the circumferential side of the second protrusion 42. The second inclined surface 421 connects the top surface of the second protrusion 42 and the root of the second protrusion 42. The top surface of the second protrusion 42 is orthogonally projected onto the root of the second protrusion 42, and the projection of the top surface of the second protrusion 42 is located within the root of the second protrusion 42. In this way, a connection surface 112 as shown in FIG. 6 can be formed on the gasket during molding.

[0045] It should be noted that the above embodiments are only used for the description of this application and do not limit the technical solutions described in this application. In this specification, the above embodiments have been used to describe this application in detail. However, those skilled in the art should understand that those skilled in the art can still correct or make equivalent substitutions to this application, and all technical solutions and their improvements that do not deviate from the spirit and scope of this application are also included within the scope of the claims of this application.

Claims

1. A method for manufacturing a gasket, comprising the following steps, namely, S1: Prepare a raw rubber and a first member, wherein the first member includes a base body and an adhesive coating layer attached to the upper surface of the base body, and the material of the base body includes a lubricating material, S2: Place the first member in the inner cavity of a molding die, wherein the molding die includes an upper die having a first main body surface in an arc shape, at least a part of the first main body surface constitutes at least a part of the upper wall surface of the inner cavity of the molding die, the molding die further includes a lower die having a second main body surface in an arc shape, at least a part of the second main body surface constitutes at least a part of the lower wall surface of the inner cavity of the molding die, and the adhesive coating layer of the first member is directed towards the upper die of the molding die, S3: Place the raw rubber in the inner cavity of the molding die, S4: Vulcanize the raw rubber placed in the inner cavity of the molding die to integrally form the raw rubber with the first member, The lower surface of the first member includes a main body surface and a connecting surface, the connecting surface is for connecting to the corresponding side wall of the through hole of the gasket in the first member, the connecting surface is inclined, along the thickness direction of the gasket, the corresponding side wall of the through hole in the first member is lower than the main body surface, and the formation of the connecting surface is characterized in that it is formed by the molding die in the step S4. A method for manufacturing a gasket.

2. The first member has flexibility, the material of the base body includes polytetrafluoroethylene, and the thickness of the first member is 0.2 mm or more and 0.6 mm or less. The method for manufacturing a gasket according to claim 1.

3. In step S1, before applying the adhesive to the substrate, a surface treatment is performed on the surface of the substrate for applying the adhesive. The adhesive coating layer includes an undercoat layer and a topcoat layer. First, the undercoat layer is applied to the upper surface of the substrate. After the undercoat layer is dried, the topcoat layer is applied to the surface of the undercoat layer and the topcoat layer is dried. The method for manufacturing a gasket according to claim 1 or 2, characterized in that.

4. In step S4, the corresponding vulcanization time is defined as the first preset time, and the corresponding preset temperature is defined as the first preset temperature. The first preset time is 3 min or more and 5 min or less, and the first preset temperature is 170 °C or more and 200 °C or less. The method for manufacturing a gasket according to any one of claims 1 to 3, characterized in that.

5. The method for realizing placing the raw rubber of a preset specification in the inner cavity of the molding die in step S3 is to put the raw rubber of the preset specification into the trough of the molding die. The trough and the molding die are located on different sides of the die partition wall. The trough and the inner cavity of the molding die communicate with each other through a supply port, and the method includes a step of pushing the raw rubber into the inner cavity of the molding die through the supply port by an extrusion process. The method for manufacturing a gasket according to claim 4, characterized in that.

6. The method for realizing placing the raw rubber of a preset specification in the inner cavity of the molding die in step S3 is to put the raw rubber into the cylinder of an injection molding machine, preheat the raw rubber in the cylinder of the injection molding machine to a second preset temperature below the first preset temperature, and the screw of the injection molding machine injects the raw rubber in the cylinder of the injection molding machine into the inner cavity of the molding die until it reaches the preset specification. The method for manufacturing a gasket according to claim 4, characterized in that.

7. Furthermore, it includes the following steps, S5: Define the integrally adhered and vulcanized raw rubber and the first member as an intermediate body, place the cooled intermediate body in a container, heat the intermediate body placed in the container, and maintain the intermediate body placed in the container at a third preset temperature within a second preset time, thereby secondary vulcanizing the intermediate body, wherein the third preset temperature is lower than the first preset temperature. The method for manufacturing a gasket according to claim 6.

8. In step S5, the second preset time is 2 h or more and 4 h or less, and the third preset temperature is 140 °C or more and 160 °C or less. The method for manufacturing a gasket according to claim 7.

9. In step S4, further including discharging the gas in the inner cavity of the molding die at least once. The method for manufacturing a gasket according to any one of claims 1 to 8.

10. Further including at least one of the following steps: S6: Remove the excess end material of the gasket. S7: Punch holes at preset positions of the gasket. The method for manufacturing a gasket according to claim 1.

11. In step S6, place the gasket in a pressing device, support the rubber layer of the gasket on a lower pressing die and contact the lower pressing die, face the first member to an upper pressing die, and form a through hole at a preset position of the gasket by a pressing action from the upper pressing die toward the lower pressing die. The method for manufacturing a gasket according to claim 10.

12. A mold, which is used as a carrier for the steps S2, S3 and S4 according to claim 1, includes a lower mold and an upper mold. The lower mold and the upper mold are clamped to form at least one inner cavity. The inner cavity includes an accommodation cavity for storing raw materials necessary for molding the gasket. The upper mold has a first main body surface in an arc shape, and at least a part of the first main body surface constitutes at least a part of the upper wall surface of the inner cavity of the mold. The mold further has a lower mold, and the lower mold has a second main body surface in an arc shape, and at least a part of the second main body surface constitutes at least a part of the lower wall surface of the inner cavity of the mold. The mold is characterized in that.

13. The upper mold further includes at least one first protrusion and a groove. The first protrusion is provided to protrude from the first main body surface, and the groove is provided to be recessed from the first main body surface. The groove is located outside the first protrusion. The first protrusion has a first inclined surface located on the circumferential side of the first protrusion. The first inclined surface connects the top surface of the first protrusion and the root of the first protrusion. The top surface of the first protrusion is orthogonally projected onto the root of the first protrusion, and the projection of the top surface of the first protrusion is located inside the root of the first protrusion. The mold according to claim 12 is characterized in that.

14. The lower mold further includes at least one second protrusion. The second protrusion is provided to protrude from the second main body surface. The second protrusion has a second inclined surface located on the circumferential side of the second protrusion. The second inclined surface connects the top surface of the second protrusion and the root of the second protrusion. The top surface of the second protrusion is orthogonally projected onto the root of the second protrusion, and the projection of the top surface of the second protrusion is located inside the root of the second protrusion. The mold according to claim 12 or 13 is characterized in that.

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