Pump valve rubber diaphragm and preparation method thereof
By using EPDM rubber and natural rubber in combination with specific additives and process steps, a high-performance pump valve rubber diaphragm was prepared, which solved the problems of slow pump valve response time and poor pressure regulation accuracy, and achieved fast response and high-precision pressure regulation.
Patent Information
- Application Number
- CN202512016194.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-02-24
AI Technical Summary
Existing pumps and valves have slow response times, poor pressure regulation accuracy, and long pressure stabilization time upon tripping.
Using EPDM rubber as the main component and natural rubber as an auxiliary component, along with specific additives and process steps, including plasticizing, internal mixing and compression molding vulcanization, a homogeneous rubber film is formed, which improves the adhesion and interfacial compatibility between the rubber and the textile fabric.
It achieves fast pump and valve response time, high pressure stabilization accuracy, short pressure stabilization time upon triggering, and features low compression settling deformation and high strength.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of rubber technology, specifically relating to a pump valve rubber diaphragm, its preparation method and application, and particularly to a pump valve rubber diaphragm with low compression set, high strength and excellent ozone aging resistance at low hardness, its preparation method and application. Background Technology
[0002] In industrial production processes, high-precision flow control pump and valve systems are required for fluid proportional control and pressure regulation, which places higher demands on the rubber diaphragms used in these pumps and valves. These rubber diaphragms can significantly shorten the response time of pump and valve flow control, improve accuracy under stable pressure conditions, and quickly stabilize the output pressure in the event of abnormal system pressure fluctuations. Summary of the Invention
[0003] To address the shortcomings of existing technologies, the present invention aims to provide a pump valve rubber diaphragm, its preparation method, and its application. The primary purpose of this rubber diaphragm is to address existing market challenges.
[0004] The problems include slow pump and valve response time, poor pressure stabilization accuracy, and long pressure stabilization time upon triggering.
[0005] To achieve this objective, the present invention adopts the following technical solution: Its composition and weight percentages are as follows: 5-20 parts natural rubber, 80-95 parts EPDM rubber, 0-2 parts homogenizer, 3-7 parts activator, 0-3 parts antioxidant, 80-120 parts plasticizer, 80-120 parts filler and reinforcing agent, 0.2-3 parts vulcanizing agent, and 3-6 parts vulcanization accelerator. The natural rubber is any one or more of natural rubber RSS1#, natural rubber SMR5#, and natural rubber SVR-CV60; RSS1# refers to natural rubber No. 1 smoked sheet rubber, SMR5# refers to natural rubber Malaysian standard No. 5 rubber, and SVR-CV60 refers to natural rubber Vietnamese standard Heng Mooney viscosity 60° rubber.
[0006] The EPDM rubber is one or more of Arlanxtech's EPDM 4465, EPDM 5470C or EPDM 8550C. When using EPDM rubber 4465, add 50 parts of white oil to every 100 parts of EPDM rubber. The homogenizer is RH-100, a mixture of aromatic and aliphatic resins from Reba Chemical. The activator is a combination of zinc oxide and stearic acid, with a mass ratio of 2-5:0.5-2. The antioxidant is polytrimethyldihydroquinoline; The plasticizer is one or more of white oil, paraffin oil, naphthenic oil, and dioctyl adipate; The filler and reinforcing agent is a combination of carbon black and silica, with a mass ratio of 70-100:5-20. The carbon black is one or more of N330, N550, and N774; N330 is a high abrasion-resistant furnace black, N550 is a fast-pressing furnace black, and N774 is a non-polluting high elongation semi-reinforcing furnace black.
[0007] The silica is silica 233 and / or silica 255 from Nanji Chemical. The vulcanizing agent is one or more of sulfur, peroxide, and sulfur-carrier crosslinking agent; The vulcanization accelerator is a combination of dithiocarbamate accelerator and chrysanthemum motherwort accelerator, with a mass ratio of 1-3:2-4.
[0008] The peroxide is dicumyl peroxide (DCP).
[0009] The sulfur-supported crosslinking agent is 4,4′-dithiodimorpholine (DTDM).
[0010] The dithiocarbamate accelerator is zinc dibutyldithiocarbamate (BZ).
[0011] The thiura mother accelerator is a combination of tetramethylthiuram monosulfide (TMTM) and tetramethylthiuram disulfide (TMTD), with a mass ratio of 1-3:1-3.
[0012] Preferably, its composition and weight parts are as follows: 5-20 parts natural rubber, 80-95 parts EPDM rubber, 0-2 parts homogenizer RH-100, 2-5 parts zinc oxide, 0.5-2 parts stearic acid, 0-3 parts antioxidant RD, 80-120 parts plasticizer, 70-100 parts carbon black, 5-20 parts silica, 0.2-3 parts vulcanizing agent, 1-3 parts dithiocarbamate accelerator BZ, 1-3 parts quaternary ammonium accelerator TMTM, and 1-3 parts quaternary ammonium accelerator TMTD.
[0013] The method for preparing the rubber diaphragm includes the following steps: 1. Plasticizing: Natural rubber and EPDM rubber are plasticized and allowed to stand on a 16-inch two-roll mill for 20-30 minutes, at a temperature of 30-100℃, and with a thickness of 0.1-1.0 mm. The settling temperature after plasticizing is 20-25℃ and the settling time is 24-72 hours. 2. A-stage mixing: The plasticized rubber from step 1 is thoroughly mixed with homogenizer, activator, antioxidant, plasticizer, and filler / reinforcing agent in a 55L internal mixer according to the formula. After mixing, discharging, sheeting, cooling, and standing, A-stage rubber is obtained. The mixing temperature is 30-140℃, the time is 10-15 minutes, the standing temperature is 20-25℃, and the standing time is 24-72 hours. 3. B mixing: The A mixing compound from step 2, along with the vulcanizing agent and vulcanization accelerator, are mixed and mixed in a 55L internal mixer. After mixing, discharging, pressing into sheets, and cooling and settling, the B mixing compound is obtained. The mixing temperature is 30-95℃, the time is 60-90 seconds, the settling temperature is 20-25℃, and the settling time is 24-72 hours.
[0014] 4. Pre-forming with adhesive: The B compound from step 3 is coated with adhesive on both sides of the textile fabric on a four-roll calender. The pre-forming temperature is 70-90℃ and the pre-forming thickness is 1.8-2.2 mm. The pre-formed part is obtained after cutting and shaping according to the film size. 5. Compression vulcanization molding: The preformed part from step 4 is subjected to compression vulcanization molding on a flat vulcanizing machine. After standing, the pump valve rubber diaphragm is obtained. The compression vulcanization molding temperature is 160-180℃, the time is 5-15 minutes, the pressure is 140-180 kgf, the standing temperature is 20-25℃, and the standing time is 24 hours.
[0015] Steps 2 and 3 involve tableting using a 16-inch two-roll open mill.
[0016] The filler, reinforcing agent, and plasticizer in step 2 are added in two stages. The first stage involves adding 1 / 2 to 2 / 3 of the filler, reinforcing agent, and 2 / 3 to 3 / 4 of the plasticizer, while the remainder is added in the second stage.
[0017] The beneficial effects of this invention are: This invention uses EPDM rubber as the main rubber and natural rubber as an auxiliary rubber, which greatly improves the adhesion between the rubber and the textile fabric. A homogenizing agent is added to improve the interfacial compatibility between polar and non-polar rubbers, preventing the formation of island phases and improving the uniformity of the compound. The components of this invention work synergistically to further improve the compression set of the rubber diaphragm at low hardness and increase its tensile strength.
[0018] This invention uses a three-stage process of plasticizing, internal mixing A, and internal mixing B to prepare the compound rubber. Under stable process conditions, natural rubber and EPDM rubber are homogeneously mixed, thereby fully utilizing the excellent comprehensive properties of the rubber diaphragm material and endowing the rubber diaphragm with good low compression set and high strength characteristics.
[0019] When this invention is applied to a regulating valve, the pressure set value can be reached in a shorter time under the set pressure, that is, the response time is fast.
[0020] When this invention is applied to a regulating valve, the fluctuation range is small under the set pressure, that is, the pressure stabilization accuracy is high.
[0021] When this invention is applied to a regulating valve, if the system pressure fluctuates abnormally under a set pressure, the output pressure can also stabilize in a short time, that is, the trip pressure stabilization time is short. Detailed Implementation
[0022] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0023] Example 1 This embodiment provides a pump valve rubber diaphragm, the raw materials for which the rubber diaphragm is prepared include the following components by weight:
[0024] The method for preparing the rubber diaphragm described in this embodiment includes the following steps: (1) Plasticizing: Natural rubber RSS1# and triethylene propylene rubber are plasticized separately with a roller gap of 0.1 mm, a plasticizing temperature of 70℃, a plasticizing time of 22 minutes, and then left to stand in an environment of 23℃ for 24 hours. (2) A-mixing: The plasticized rubber in step (1) is thoroughly mixed with homogenizer, activator, antioxidant, plasticizer and filler reinforcing agent according to the formula amount, then mixed, discharged, pressed into sheets, cooled and allowed to stand to obtain A-mixed rubber. The A-mixing time is 12 minutes, the A-mixing temperature is 135℃, and it is allowed to stand in an environment of 23℃ for 24 hours. (3) B mixing: The A mixing rubber from step (2) is mixed with vulcanizing agent and vulcanization accelerator, mixed, discharged, pressed into sheets, cooled and left to stand to obtain B mixing rubber. The B mixing time is 70 seconds, the B mixing temperature is 90℃, and it is left to stand in an environment of 23℃ for 24 hours. (4) Pre-forming with adhesive: The B compound from step (3) is coated with adhesive on both sides of the textile fabric. The pre-formed part is obtained by cutting and shaping according to the size of the film. The adhesive temperature is 80℃ and the thickness of the pre-formed part is 1.9 mm. (5) Compression vulcanization molding: The preformed part from step (4) is subjected to compression vulcanization molding. After standing, the pump valve rubber diaphragm is obtained. The vulcanization temperature is 172℃, the vulcanization pressure is 160kgf, the vulcanization time is 12 minutes, and after vulcanization, it is placed in an environment of 23℃.
[0025] Example 2 The only difference between this embodiment and Example 1 is that the content of natural rubber RSS1# is increased to 10 kg, the content of EPDM 5470C is reduced to 30 kg, the content of homogenizer RH-100 is increased to 1.0 kg, the content of carbon black N550 is increased to 78 kg, the content of sulfur is increased to 0.8 kg, the content of vulcanizing agent DTDM is reduced to 0.8 kg, and the contents of vulcanization accelerators BZ, TMTM, and TMTD are all reduced to 1.2 kg. The contents of other components and the preparation method are the same as in Example 1.
[0026] Example 3 The only difference between this embodiment and Example 1 is that the content of natural rubber RSS1# is increased to 15 kg, the content of EPDM 5470C is reduced to 25 kg, the content of homogenizer RH-100 is increased to 1.5 kg, the content of carbon black N550 is increased to 80 kg, the content of sulfur is increased to 1.0 kg, the content of vulcanizing agent DTDM is reduced to 0.5 kg, and the contents of vulcanization accelerators BZ, TMTM, and TMTD are all reduced to 1.0 kg. The contents of other components and the preparation method are the same as in Example 1.
[0027] Example 4 The only difference between this embodiment and Embodiment 1 is that natural rubber RSS1# is replaced with natural rubber SMR5#, and EPDM rubber 5470C is replaced with EPDM rubber 8550C. The content of other components and the preparation method are the same as in Embodiment 1.
[0028] Example 5 The only difference between this embodiment and embodiment 2 is that natural rubber RSS1# is replaced with natural rubber SMR5#, and EPDM rubber 5470C is replaced with EPDM rubber 8550C. The content of other components and the preparation method are the same as in embodiment 2.
[0029] Example 6 The only difference between this embodiment and embodiment 3 is that natural rubber RSS1# is replaced with natural rubber SMR5#, and EPDM rubber 5470C is replaced with EPDM rubber 8550C. The content of other components and the preparation method are the same as in embodiment 3.
[0030] Example 7 The only difference between this embodiment and Embodiment 1 is that natural rubber RSS1# is replaced with natural rubber SVR-CV60, paraffin oil is replaced with white oil, and silica 233 is replaced with silica 255. The content of other components and the preparation method are the same as in Embodiment 1.
[0031] Example 8 The only difference between this embodiment and Embodiment 2 is that natural rubber RSS1# is replaced with natural rubber SVR-CV60, paraffin oil is replaced with white oil, and silica 233 is replaced with silica 255. The content of other components and the preparation method are the same as in Embodiment 2.
[0032] Example 9 The only difference between this embodiment and embodiment 3 is that natural rubber RSS1# is replaced with natural rubber SVR-CV60, paraffin oil is replaced with white oil, and silica 233 is replaced with silica 255. The content of other components and the preparation method are the same as in embodiment 3.
[0033] Performance testing The basic performance and application performance of the above embodiments were tested respectively, and the specific test results are shown in Table 1 below: Table 1 As shown in Table 1, the shortest response time of the pressure regulating valve can reach 0.056 seconds, the pressure regulation accuracy is ±1.22%, and the trigger pressure stabilization time is 0.043 seconds, which is basically at the leading level in the industry.
[0034] The applicant declares that this invention illustrates the rubber diaphragm, its preparation method, and its application through the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials of the product of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.
Claims
1. A pump valve rubber diaphragm, characterized in that, Its composition and weight percentages are as follows: 5-20 parts natural rubber, 80-95 parts EPDM rubber, 0-2 parts homogenizer, 3-7 parts activator, 0-3 parts antioxidant, 80-120 parts plasticizer, 80-120 parts filler and reinforcing agent, 0.2-3 parts vulcanizing agent, and 3-6 parts vulcanization accelerator. The natural rubber is one or more of natural rubber RSS1#, natural rubber SMR5#, and natural rubber SVR-CV60; the EPDM rubber is one or more of EPDM rubber 4465, EPDM rubber 5470C, or EPDM rubber 8550C. The homogenizer is a mixture of aromatic and aliphatic resins; The activator is a combination of zinc oxide and stearic acid, with a mass ratio of 2-5:0.5-2. The antioxidant is polytrimethyldihydroquinoline; The plasticizer is one or more of white oil, paraffin oil, naphthenic oil, and dioctyl adipate; The filler and reinforcing agent is a combination of carbon black and silica, with a mass ratio of 70-100:5-20. The carbon black is one or more of N330, N550, and N774; The silica is silica 233 and / or silica 255; The vulcanizing agent is one or more of sulfur, peroxide, and sulfur-carrier crosslinking agent; The vulcanization accelerator is a combination of dithiocarbamate accelerator and chrysanthemum motherwort accelerator, with a mass ratio of 1-3:2-4.
2. The pump valve rubber diaphragm according to claim 1, characterized in that, The peroxide is diisopropylbenzene peroxide.
3. The pump valve rubber diaphragm according to claim 1, characterized in that, The sulfur-supported crosslinking agent is 4,4′-dithiodimorpholine.
4. The pump valve rubber diaphragm according to claim 1, characterized in that, The dithiocarbamate accelerator is zinc dibutyldithiocarbamate.
5. The pump valve rubber diaphragm according to claim 1, characterized in that, The thiura mother accelerator is a combination of tetramethylthiuram monosulfide and tetramethylthiuram disulfide, with a mass ratio of 1-3:1-3.
6. A method for preparing the pump valve rubber diaphragm according to claim 1, characterized in that, Specifically, the following steps are included: (1) Plasticizing: Natural rubber and ethylene propylene rubber are plasticized and allowed to stand on a 16-inch two-roll mill. The plasticizing time is 20-30 minutes, the plasticizing temperature is 30-100℃, and the plasticizing thickness is 0.1-1.0 mm. The standing temperature after plasticizing is 20-25℃ and the standing time is 24-72 hours. (2) A-component: The plasticized rubber from step 1) is thoroughly mixed with homogenizer, activator, antioxidant, plasticizer and filler reinforcing agent in a 55L internal mixer according to the formula amount. After mixing, discharging, pressing, cooling and standing, the A-component rubber is obtained. The mixing temperature is 30-140℃, the time is 10-15 minutes, the standing temperature is 20-25℃, and the standing time is 24-72 hours. (3) B mixing: The A mixing rubber from step 2) and vulcanizing agent and vulcanization accelerator are mixed and mixed in a 55L internal mixer, discharged, pressed into sheets, cooled and allowed to stand to obtain B mixing rubber; the mixing temperature is 30-95℃, the time is 60-90 seconds, the standing temperature is 20-25℃, and the standing time is 24-72 hours. (4) Pre-forming with adhesive: The B compound of step 3) is coated with adhesive on both sides of the textile fabric on a four-roll calender. The pre-forming temperature is 70-90℃ and the pre-forming thickness is 1.8-2.2 mm. The pre-formed part is obtained after cutting and forming according to the film size. (5) Compression vulcanization molding: The preformed part of step 4) is subjected to compression vulcanization molding on a flat vulcanizing machine. After standing, the pump valve rubber diaphragm is obtained. The compression vulcanization molding temperature is 160-180℃, the time is 5-15 minutes, the pressure is 140-180kgf, the standing temperature is 20-25℃, and the standing time is 24 hours.
7. The method for preparing the pump valve rubber diaphragm according to claim 6, characterized in that, Steps 2) and 3) are performed using a 16-inch two-roll open mill for tableting.
8. The method for preparing the pump valve rubber diaphragm according to claim 6, characterized in that, The filler and plasticizer in step 2) are added in two parts. The first part consists of 1 / 2 to 2 / 3 of the filler and 2 / 3 to 3 / 4 of the plasticizer, and the rest is added in the second part.