Metal rubber composite material applied to liquid hydrogen seal and preparation process thereof

Abstract

The application discloses a metal-rubber composite material applied to liquid hydrogen sealing and a preparation process, and belongs to the field of high polymer compound compositions. The composite material components include a rubber matrix and necessary components in weight parts. The rubber matrix comprises 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fiber, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fiber, 1-3 parts of liquid crystal polymer, 0.5-1.5 parts of metal micro powder, 3-7 parts of silicone rubber and 1-3 parts of fluororubber. The necessary components include 3-7.5 parts of an accelerator, 1-3 parts of a coupling agent and 2-5 parts of an anti-aging agent. The accelerator comprises a main accelerator, an auxiliary accelerator and a vulcanization activator, and the main accelerator is at least one or more of thiazoles. The application aims to solve the problems that, in the prior art, the mixing of the composite material lacks an accelerator, the sealing ring after forming consumes too much time during vulcanization and the crosslinking density during vulcanization is insufficient.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen pump sealing technology, specifically to a metal-rubber composite material for liquid hydrogen sealing and its preparation process. Background Technology

[0002] Liquid hydrogen pump sealing technology is a key technology in the aerospace and energy sectors, primarily used in liquid hydrogen storage and transportation systems. Liquid hydrogen, as a highly efficient and clean fuel, is widely used in rocket propulsion and hydrogen-powered vehicles. However, the extremely low temperatures of liquid hydrogen present numerous challenges during the sealing process, such as material shrinkage and embrittlement due to temperature changes, which can lead to seal failure. Therefore, developing high-performance sealing materials and structures to ensure the safety and stability of liquid hydrogen during storage and transportation has become a key research focus. This technology is not only crucial for the efficient utilization of liquid hydrogen but also significantly contributes to improving the overall system's safety and reliability.

[0003] The invention patent with application number CN202011228163.7 and publication number CN112521667A (hereinafter referred to as "Prior Art 1") discloses a composite rubber, a high wear-resistant sealing composite material and its preparation method. The high wear-resistant sealing composite material of the present invention comprises the following components in parts by weight: composite rubber: 133-150 parts, carbon black: 50-70 parts, vulcanizing agent: 4-8 parts, coupling agent: 4-7 parts, plasticizer: 2-8 parts, antioxidant: 3.5-7 parts, active zinc oxide: 3-5 parts, stearic acid: 0.5-1.5 parts; the composite rubber comprises the following components in parts by weight: nitrile rubber: 80-90 parts, polyurethane rubber: 20-10 parts, polytetrafluoroethylene micro powder: 20-30 parts, nano reinforcing agent: 12-18 parts, organotin heat stabilizer: 1-2 parts.

[0004] The specification of prior art 1 discloses a composite rubber, a high wear-resistant sealing component composite material, and its preparation method. In use, the composite rubber is first refined separately, and then other materials are added step by step for mixing. Through reasonable formula design and process optimization, the composite material is obtained. However, in actual applications, since the sealing ring needs to be vulcanized after molding to improve its performance, without the addition of an accelerator, the reaction speed between the pure vulcanizing agent (such as sulfur) and the rubber molecules is very slow. Vulcanization by high temperature heating alone may take several hours or even longer to complete the vulcanization process. Furthermore, without the addition of an accelerator, the vulcanization reaction efficiency of the rubber base material itself is low. Without an accelerator, fewer chemical bonds are formed between sulfur and rubber molecules, resulting in insufficient crosslinking density. Summary of the Invention

[0005] This invention provides a metal-rubber composite material for liquid hydrogen sealing and its preparation process, aiming to solve the problems in the prior art where the lack of accelerators during the mixing of composite materials leads to excessively long vulcanization time and insufficient crosslinking density during vulcanization of the molded sealing ring.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A metal-rubber composite material for liquid hydrogen sealing, comprising, by weight, a rubber matrix and necessary components;

[0008] The rubber matrix comprises: 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fiber, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fiber, 1-3 parts of liquid crystal polymer, 0.5-1.5 parts of metal powder, 3-7 parts of silicone rubber, and 1-3 parts of fluororubber.

[0009] The necessary components include: 3-7.5 parts of accelerator, 1-3 parts of coupling agent, and 2-5 parts of antioxidant; the accelerator includes a main accelerator, an auxiliary accelerator, and a vulcanization activator, wherein the main accelerator is at least one or more of thiazoles, and the thiazoles are 0.5-1.5 parts of the rubber base material.

[0010] Further, the rubber matrix comprises: 55-65 parts of polytetrafluoroethylene, 12-18 parts of polyimide, 8-12 parts of graphite, 4.5-5.5 parts of carbon fiber, 1.5-3.5 parts of molybdenum disulfide, 3-5 parts of glass fiber, 1.5-2.5 parts of liquid crystal polymer, 0.75-1.25 parts of metal powder, 4-6 parts of silicone rubber, and 1.5-2.5 parts of fluororubber.

[0011] Further, the main accelerator includes at least one selected from 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxodiethylbenzothiazole sulfenamide, diisopropylthioaminobenzothiazole, zinc salt of 2-mercaptobenzothiazole, and N-methyldibenzothiazole sulfenamide.

[0012] Furthermore, the auxiliary accelerator is at least one of guanidines, and the sulfurization activator is at least one of zinc oxide and stearic acid.

[0013] Furthermore, the guanidine-based accelerator includes at least one of diphenylguanidine, N,N'-diphenylthiourea, N,N'-dicyclohexylthiourea, and tolueneguanidine.

[0014] Furthermore, the coupling agent includes at least one of silane coupling agents and titanate coupling agents.

[0015] Furthermore, the antioxidant includes phenolic antioxidants, amine antioxidants, and ozone-resistant antioxidants, with the components comprising, by weight, 0.5-2 parts of phenolic antioxidants, 1-2 parts of amine antioxidants, and 0.5-1 parts of ozone-resistant antioxidants.

[0016] Furthermore, the necessary components also include 0.5-1 parts of low-temperature flexibility modifier, 3-6 parts of filler, and 1-2 parts of toughening agent.

[0017] A process for preparing a metal-rubber composite material for liquid hydrogen sealing includes preparing a sealing ring using the aforementioned composite material. The preparation process includes the following steps:

[0018] (1) Adjust the temperature and speed of the mixer, add the rubber base material and necessary components to the mixer in sequence for mixing, and finally collect the refined rubber material.

[0019] (2) The refined rubber material is placed into the injection mold for molding, and the sealing ring is finally formed. The sealing ring is then removed after molding.

[0020] (3) Trim the formed sealing ring to ensure that there are no burrs on the surface of the sealing ring;

[0021] (4) The shaped sealing ring is placed in a vulcanizing furnace for vulcanization;

[0022] (5) Remove the vulcanized sealing ring;

[0023] (6) Measure the thickness of the sealing ring. If the thickness is qualified, collect it. If the thickness is >5mm, repeat step (4) and vulcanize for 1-2 minutes again.

[0024] Furthermore, in step (4), the temperature in the vulcanizing furnace is 160℃-180℃, the vulcanizing pressure in the vulcanizing furnace is 8MPa-12MPa, and the vulcanizing time is 8-15min.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention mainly includes a rubber matrix and necessary components. In actual use, the operator first adjusts the temperature and speed of the mixing mill, then adds the rubber matrix and necessary components to the mixing mill sequentially for mixing. The mixed rubber material is then collected and placed into an injection mold for molding, ultimately forming the sealing ring. After molding, the sealing ring is removed. The formed sealing ring is then trimmed to ensure its surface is free of burrs. The shaped sealing ring is then placed in a vulcanizing furnace for vulcanization. Finally, the vulcanized sealing ring is removed to form the finished sealing ring. During this process, the thickness of the sealing ring needs to be measured. If the thickness is within acceptable limits, it is collected; if the thickness is greater than 5mm, it is vulcanized again for 1-2 minutes. The advantage of this setup is that the addition of thiazole-based accelerators, coupling agents, and antioxidants to the rubber matrix allows the sulfur and rubber molecules to undergo a rapid and thorough cross-linking reaction during vulcanization, resulting in a more efficient and effective overall vulcanization process. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is one of the structural schematic diagrams of the preparation device in this invention.

[0029] Figure 2 This is the second schematic diagram of the preparation device in this invention.

[0030] In the diagram, 101-frame, 102-upper adjusting plate, 103-lower adjusting plate, 104-telescopic assembly, 105-first heating roller, 106-second heating roller, 107-support rod, 108-hinge, 109-connecting bar, 110-motor, 111-sprocket drive mechanism, 112-gear drive mechanism. Detailed Implementation

[0031] The present invention will be further described below with reference to embodiments. These embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the protection scope of the present invention.

[0032] This embodiment discloses a metal-rubber composite material for liquid hydrogen sealing, the components of which, by weight, include: a rubber matrix and necessary components;

[0033] The rubber matrix comprises: 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fiber, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fiber, 1-3 parts of liquid crystal polymer, 0.5-1.5 parts of metal powder, 3-7 parts of silicone rubber, and 1-3 parts of fluororubber.

[0034] The necessary components include: 3-7.5 parts of accelerator, 1-3 parts of coupling agent, and 2-5 parts of antioxidant; the accelerator includes a main accelerator, an auxiliary accelerator, and a vulcanization activator, wherein the main accelerator is at least one or more of thiazoles, and the thiazoles are 0.5-1.5 parts of the rubber base material;

[0035] This invention mainly includes a rubber matrix and necessary components. In actual use, the operator first adjusts the temperature and speed of the mixing mill, then adds the rubber matrix and necessary components to the mixing mill sequentially for mixing. The mixed rubber material is then collected and placed into an injection mold for molding, ultimately forming the sealing ring. After molding, the sealing ring is removed. The formed sealing ring is then trimmed to ensure its surface is free of burrs. The shaped sealing ring is then placed in a vulcanizing furnace for vulcanization. Finally, the vulcanized sealing ring is removed to form the finished sealing ring. During this process, the thickness of the sealing ring needs to be measured. If the thickness is within acceptable limits, it is collected; if the thickness is greater than 5mm, it is vulcanized again for 1-2 minutes. The advantage of this setup is that the addition of thiazole-based accelerators, coupling agents, and antioxidants to the rubber matrix allows the sulfur and rubber molecules to undergo a rapid and thorough cross-linking reaction during vulcanization, resulting in a more efficient and effective overall vulcanization process.

[0036] In some embodiments, the rubber matrix comprises: 55-65 parts of polytetrafluoroethylene, 12-18 parts of polyimide, 8-12 parts of graphite, 4.5-5.5 parts of carbon fiber, 1.5-3.5 parts of molybdenum disulfide, 3-5 parts of glass fiber, 1.5-2.5 parts of liquid crystal polymer, 0.75-1.25 parts of metal powder, 4-6 parts of silicone rubber, and 1.5-2.5 parts of fluororubber.

[0037] As an optional implementation, in this embodiment, the rubber base material is selected by weight as follows: 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micro powder, 5 parts of silicone rubber, and 2 parts of fluororubber; the necessary components are selected by weight as follows: 1 part of main catalyst, 0.75 parts of auxiliary catalyst, 3.5 parts of vulcanization activator, 2 parts of coupling agent, and 3.5 parts of antioxidant.

[0038] In use, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micro powder, 5 parts of silicone rubber, and 2 parts of fluororubber are first poured into a mixer for mixing. Then, 1 part of main catalyst, 0.75 parts of auxiliary catalyst, 3.5 parts of vulcanization activator, 2 parts of coupling agent, and 3.5 parts of antioxidant are added and mixed to incorporate accelerators, coupling agents, and antioxidants into the rubber base material.

[0039] In some embodiments, the main accelerator includes at least one selected from 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxodiethylbenzothiazole sulfenamide, diisopropylthioaminobenzothiazole, zinc salt of 2-mercaptobenzothiazole, and N-methyldibenzothiazole sulfenamide.

[0040] In some embodiments, the auxiliary promoter is at least one of guanidines, and the sulfurization activator is at least one of zinc oxide and stearic acid.

[0041] In some embodiments, the guanidine auxiliaries include at least one of diphenylguanidine, N,N'-diphenylthiourea, N,N'-dicyclohexylthiourea, and tolueneguanidine.

[0042] In some embodiments, the coupling agent includes at least one of silane coupling agents and titanate coupling agents.

[0043] In some embodiments, the antioxidant includes phenolic antioxidants, amine antioxidants, and ozone-resistant antioxidants, wherein the components, by weight, are 0.5-2 parts of phenolic antioxidants, 1-2 parts of amine antioxidants, and 0.5-1 parts of ozone-resistant antioxidants.

[0044] In practical use, the components, by weight, are: 1.25 parts phenolic antioxidant, 1.5 parts amine antioxidant, and 0.75 parts anti-ozone antioxidant.

[0045] In some embodiments, the necessary components further include 0.5-1 parts of a low-temperature flexibility modifier, 3-6 parts of a filler, and 1-2 parts of a toughening agent.

[0046] In actual use, the components also need to be added by weight: 0.75 parts of gentle toughness modifier, 4.5 parts of filler, and 1.5 parts of toughening agent.

[0047] As an optional implementation, in this embodiment, the main accelerators are selected from 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxydiethylbenzothiazole sulfenamide, diisopropylthioaminobenzothiazole, zinc salt of 2-mercaptobenzothiazole, and N-methyldibenzothiazole sulfenamide. The guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, and the coupling agent is a silane coupling agent. Then, 0.75 parts of antioxidant, 0.5 parts of gentleness modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added. By adding 8 different main accelerators while keeping other materials unchanged, 8 experiments are conducted to test the hardness, tensile strength, and elongation at break of the sealing ring. The purpose is to verify which main accelerator has the best mixing effect on the sealing ring.

[0048] When 2-mercaptobenzothiazole is selected as the main accelerator, diphenylguanidine is selected as the guanidine auxiliary accelerator, zinc oxide is selected as the vulcanization activator, and silane coupling agent is selected as the coupling agent. Then, 0.75 parts of antioxidant, 0.5 parts of gentle toughening modifier, 4.5 parts of filler and 1.5 parts of toughening agent are added and recorded as Experiment 1.

[0049] The specific operating procedures in Experiment 1 are as follows:

[0050] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are first added to a mixer for mixing. Then, 1 part of 2-mercaptobenzothiazole, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0051]

[0052] In some embodiments, when the main accelerator is dibenzothiazole disulfide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is silane coupling agent, and then an antioxidant, a gentle and tough modifier of 0.75 parts, a filler of 4.5 parts, and a toughening agent of 1.5 parts are added, and this is recorded as Experiment 2.

[0053] The specific operating procedures in Experiment 2 are as follows:

[0054] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are added to a mixer for mixing. Then, 1 part of dibenzothiazole disulfide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0055]

[0056] In some embodiments, when N-cyclohexyl-2-benzothiazole sulfenamide is selected as the main accelerator, diphenylguanidine is selected as the guanidine auxiliary accelerator, zinc oxide is selected as the vulcanization activator, silane coupling agent is selected as the coupling agent, and then 0.75 parts of antioxidant, 0.5 parts of gentle toughening modifier, 4.5 parts of filler and 1.5 parts of toughening agent are added, and it is recorded as Experiment 3.

[0057] The specific operating procedures in Experiment 3 are as follows:

[0058] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are mixed in a mixer. Then, 1 part of N-cyclohexyl-2-benzothiazole sulfenamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0059]

[0060] In some embodiments, when the main accelerator is N-tert-butyl-2-benzothiazole sulfenamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is silane coupling agent, and then an antioxidant, a gentle and toughening modifier of 0.75 parts, a filler of 4.5 parts and a toughening agent of 1.5 parts are added, and this is recorded as Experiment 4.

[0061] The specific operating procedures in Experiment 4 are as follows:

[0062] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are mixed in a mixer. Then, 1 part of N-tert-butyl-2-benzothiazole sulfenamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0063]

[0064]

[0065] In some embodiments, when the main accelerator is N-oxydiethylbenzothiazole sulfenamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is silane coupling agent, and then an antioxidant, a gentle and toughening modifier of 0.75 parts, a filler of 4.5 parts, and a toughening agent of 1.5 parts are added, and this is recorded as Experiment 5.

[0066] The specific operating procedures in Experiment 5 are as follows:

[0067] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are first added to a mixer for mixing. Then, 1 part of N-oxydiethylbenzothiazole sulfenamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0068]

[0069] In some embodiments, when the main accelerator is diisopropylthioaminobenzothiazole, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is silane coupling agent, and then an antioxidant, a gentle toughening modifier of 0.75 parts, a filler of 4.5 parts, and a toughening agent of 1.5 parts are added, and this is recorded as Experiment Six.

[0070] The specific operating procedures for Experiment Six are as follows:

[0071] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are first added to a mixer for mixing. Then, 1 part of diisopropylthioaminobenzothiazole, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0072]

[0073] In some embodiments, when the main accelerator is zinc salt of 2-mercaptobenzothiazole, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is silane coupling agent, and then 0.75 parts of antioxidant, 0.5 parts of gentle toughening modifier, 4.5 parts of filler and 1.5 parts of toughening agent are added, and recorded as Experiment Seven.

[0074] The specific operating procedures in Experiment 7 are as follows:

[0075] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are added to a mixer for mixing. Then, 1 part of 2-mercaptobenzothiazole zinc salt, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0076]

[0077] In some embodiments, when N-methyldibenzothiazole sulfenamide is selected as the main accelerator, diphenylguanidine is selected as the guanidine auxiliary accelerator, zinc oxide is selected as the vulcanization activator, silane coupling agent is selected as the coupling agent, and then 0.75 parts of antioxidant, 0.5 parts of gentle toughening modifier, 4.5 parts of filler and 1.5 parts of toughening agent are added, and recorded as Experiment 8.

[0078] The specific operating procedures in Experiment 8 are as follows:

[0079] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber, and 2 parts of fluororubber are added to a mixer for mixing. Then, 1 part of N-methyldibenzothiazole sulfenamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of flexibility modifier, 4.5 parts of filler, and 1.5 parts of toughening agent are added to the mixer and mixed with the above rubber base materials. The hardness of the sealed ring is tested using a hardness tester, and the tensile strength and elongation at break are tested using a tensile testing fixture. The experimental data are shown in the table below.

[0080]

[0081] Therefore, based on the data from Experiments 1-8, a suitable primary accelerator can be selected according to the actual requirements for hardness, tensile strength, and elongation at break.

[0082] In some different embodiments, the present invention also includes a process for preparing a metal-rubber composite sealing ring for liquid hydrogen sealing, comprising preparing the sealing ring using the aforementioned composite material, the preparation process comprising the following steps:

[0083] (1) Adjust the temperature and speed of the mixer, add the rubber base material and necessary components to the mixer in sequence for mixing, and finally collect the refined rubber material.

[0084] (2) The refined rubber material is placed into the injection mold for molding, and the sealing ring is finally formed. The sealing ring is then removed after molding.

[0085] (3) Trim the formed sealing ring to ensure that there are no burrs on the surface of the sealing ring;

[0086] (4) The shaped sealing ring is placed in a vulcanizing furnace for vulcanization;

[0087] (5) Remove the vulcanized sealing ring;

[0088] (6) Measure the thickness of the sealing ring. If the thickness is qualified, collect it. If the thickness is >5mm, repeat step (4) and vulcanize for 1-2 minutes again.

[0089] Furthermore, in step (4), the temperature in the vulcanizing furnace is 160℃-180℃, the vulcanizing pressure in the vulcanizing furnace is 8MPa-12MPa, and the vulcanizing time is 8-15min.

[0090] Please see Figure 1 as well as Figure 2As shown, in some different embodiments, the sealing ring is prepared by a preparation device, which includes a mixing device, a compression molding device, and a vulcanizing device; the mixing device is used to mix raw materials and additives to form a rubber compound; the compression molding device is used to compress and mold the rubber compound; and the vulcanizing device is used to vulcanize the molded sealing ring to enhance its mechanical strength, heat resistance, and elasticity.

[0091] The mixing device includes a frame 101, a drive assembly, a heating roller assembly, and an adjustment assembly. The drive assembly is mounted on the frame 101, and the heating roller assembly is rotatably mounted on the frame 101. The drive assembly drives the heating roller assembly to rotate. The adjustment assembly includes an upper adjustment plate 102 and a lower adjustment plate 103. The upper adjustment plate 102 is located directly above the heating roller assembly, and the heating roller assembly and the upper adjustment plate 102 are in sliding engagement. The upper adjustment plate 102 is used to adjust the width of the raw material to be mixed. The lower adjustment plate 103 is rotatably mounted below the heating roller assembly via a telescopic assembly 104, which is hinged to the frame 101. The lower adjustment plate 103 is used to adjust the thickness of the raw material to be mixed.

[0092] This invention mainly includes a mixing device, a molding device, and a vulcanizing device. In actual use, the operator first loads the raw material for making the sealing ring into a container, then slides the position of the upper adjusting plate 102 above the hot roller assembly, so that a certain width is formed between the two upper adjusting plates 102. Then, the telescopic component 104 is controlled to extend, and after the telescopic component 104 extends, the lower adjusting plate 103 is controlled to rotate, thereby creating a gap between the lower adjusting plate 103 and the hot roller assembly. Then, the raw material for making the sealing ring in the container is poured directly above the hot roller assembly, and then the drive component is started. The drive component controls the hot roller assembly to rotate in opposite directions, thereby repeatedly crushing the raw material for making the sealing ring. When the raw material for making the sealing ring is squeezed and mixed by the hot roller assembly, it adheres to the hot roller assembly and rotates with the hot roller assembly. At this time, the adhesive adhered to the hot roller assembly is first adjusted by the lower adjusting plate 103 to form a certain thickness, which is slightly smaller than the gap between the lower adjusting plate 103 and the hot roller assembly. The adhesive is heated from the hot roller assembly. When the roller assembly moves from below to above the hot roller assembly, the adhesive on the hot roller assembly is positioned by the upper adjusting plate 102. At this time, the adhesive on the hot roller assembly moves between the two upper adjusting plates 102, which gather the adhesive together. This process repeatedly refining the adhesive on the hot roller assembly forms a mixed rubber material. The refined rubber is then placed into a compression molding device for molding to form a sealing ring. Finally, the molded sealing ring is placed into a vulcanizing device for vulcanization, resulting in better mechanical strength, heat resistance, and elasticity of the sealing ring. The advantage of this setup is that the position of the adhesive on the hot roller assembly is adjusted by the upper adjusting plate 102 and the lower adjusting plate 103, eliminating the need for manual adjustment and saving labor costs. Furthermore, the upper adjusting plate 102 and the lower adjusting plate 103 allow for better gathering of the adhesive on the hot roller assembly, resulting in better rubber refining.

[0093] In some embodiments, the heating roller assembly includes a first heating roller 105 and a second heating roller 106, both of which are rotatably mounted on the frame 101. The bottom edge of the upper adjusting plate 102 is used to contact the first heating roller 105 and the second heating roller 106, and the lower adjusting plate 103 is used to contact the rubber material on the first heating roller 105 and the second heating roller 106.

[0094] In actual use, the staff pours the raw material for making the sealing ring onto the first heating roller 105 and the second heating roller 106. After the first heating roller 105 and the second heating roller 106 rotate in opposite directions, they crush the raw material for making the sealing ring, so that the raw material for making the sealing ring sticks to the first heating roller 105 and the second heating roller 106. Through the continuous rotation of the first heating roller 105 and the second heating roller 106, the adhesive on the second heating roller 106 adheres to the first heating roller 105, and finally forms a rubber material.

[0095] In some embodiments, the frame 101 is provided with two support rods 107 and two hinges 108. The support rods 107 are rotatably connected to the frame 101. A connecting strip 109 is fixedly installed on the support rod 107. One end of the telescopic component 104 is hinged to the connecting strip 109 and the other end is hinged to the hinge 108. A lower adjusting plate 103 is fixedly installed on each support rod 107.

[0096] In actual use, there are two telescopic components 104. The two telescopic components 104 are respectively hinged to the frame 101 and located at the bottom of the first heating roller 105 and the second heating roller 106.

[0097] As an optional implementation, in this embodiment, the telescopic component 104 is specifically a cylinder. When in use, when the cylinder extends, the movable end of the cylinder pushes the connecting strip 109, and the connecting strip 109 pulls the support rod 107, causing the support rod 107 to rotate around the frame 101. Since the support rod 107 is fixedly connected to the lower adjusting plate 103, the rotation of the support rod 107 causes the lower adjusting plate 103 to rotate towards the hot roller assembly, thereby realizing the adjustment of the angle of the lower adjusting plate 103.

[0098] In some embodiments, the drive assembly includes a motor 110 and a transmission mechanism. The motor 110 is mounted on the frame 101, and the motor 110 drives the first heating roller 105 and the second heating roller 106 to rotate on the frame 101 through the transmission mechanism.

[0099] In actual use, the transmission mechanism mainly includes a sprocket transmission mechanism 111 and a gear transmission mechanism 112. The motor 110 drives the first heating roller 105 to rotate through the sprocket rotation mechanism and drives the second heating roller 106 to rotate through the gear transmission mechanism 112.

[0100] As an optional implementation, in this embodiment, the sprocket drive mechanism 111 includes a driving sprocket, a driven sprocket, and a chain, and the gear drive mechanism 112 includes a driving gear and a driven gear. The driving sprocket is fixedly mounted on the output shaft of the motor 110, the driven sprocket is fixedly mounted on the end of the first heating roller 105, the driving gear is fixedly mounted on the end of the first heating roller 105 away from the driven sprocket, and the driven gear is fixedly mounted on the end of the second heating roller 106 near the driving gear. The driving gear and the driven gear mesh with each other, and the chain is fitted onto the driving sprocket and the driven sprocket.

[0101] In use, the motor 110 drives the drive sprocket to rotate. After the drive sprocket rotates, it drives the driven sprocket to rotate under the action of the chain. After the driven sprocket rotates, the first heating roller 105 rotates. After the first heating roller 105 rotates, the second heating roller 106 rotates together with the first heating roller 105 under the action of the meshing of the drive gear and the driven gear. Since the drive gear and the driven gear form an external mesh, the first heating roller 105 and the second heating roller 106 rotate in opposite directions, and the first heating roller 105 and the second heating roller 106 rotate in opposite directions to each other.

[0102] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0103] Furthermore, the terms “first,” “second,” “third,” and “fourth” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as “first,” “second,” “third,” or “fourth” may explicitly or implicitly include at least one of those features.

[0104] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0105] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mixing apparatus, characterized in that, The assembly includes a frame, a drive assembly, a heating roller assembly, and an adjustment assembly. The drive assembly is mounted on the frame, and the heating roller assembly is rotatably mounted on the frame. The drive assembly drives the heating roller assembly to rotate. The adjustment assembly includes an upper adjustment plate and a lower adjustment plate. The upper adjustment plate is located directly above the heating roller assembly, and the heating roller assembly and the upper adjustment plate are in sliding engagement. The upper adjustment plate is used to adjust the width of the raw material to be mixed. The lower adjustment plate is rotatably mounted below the heating roller assembly via a telescopic assembly, which is hinged to the frame. The lower adjustment plate is used to adjust the thickness of the raw material to be mixed. When the raw materials for making rubber are squeezed and mixed by the hot roller assembly, they adhere to the hot roller assembly and rotate with it. At this time, the rubber adhering to the hot roller assembly is first adjusted by the lower adjusting plate to form a thickness that is slightly smaller than the gap between the lower adjusting plate and the hot roller assembly. When the rubber moves from below the hot roller assembly to above the hot roller assembly, the position of the rubber adhering to the hot roller assembly is restricted by the upper adjusting plate. At this time, the rubber adhering to the hot roller assembly moves between the two upper adjusting plates. The two upper adjusting plates gather the rubber adhering to the hot roller assembly, and then repeatedly refining the rubber adhering to the hot roller assembly. The heating roller assembly includes a first heating roller and a second heating roller. The bottom edge of the upper adjusting plate is used to contact the first heating roller and the second heating roller, and the lower adjusting plate is used to contact the rubber material on the first heating roller and the second heating roller. The frame is equipped with two support rods and two hinges. The support rods are rotatably connected to the frame. A connecting strip is fixedly installed on the support rod. One end of the telescopic component is hinged to the connecting strip and the other end is hinged to the hinge. Each support rod is fixedly equipped with a lower adjustment plate. There are two telescopic components, which are hinged to the frame and located at the bottom of the first heating roller and the second heating roller, respectively.

2. The mixing apparatus according to claim 1, characterized in that: Both the first heating roller and the second heating roller are rotatably mounted on the frame.

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