Pressure-compensated drip irrigation emitter elastic diaphragm and preparation method and application thereof

Abstract

This invention relates to an elastic diaphragm for pressure-compensating drip irrigation emitters, its preparation method, and its application. The elastic diaphragm provided by this invention comprises a double-layered composite elastic diaphragm consisting of a mound-shaped elastic diaphragm and a flat elastic diaphragm. The hardness of the mound-shaped elastic diaphragm is 48-58 HA; the hardness of the flat elastic diaphragm is 42-52 HA; and the hardness of the flat elastic diaphragm is 8-12 HA greater than that of the mound-shaped elastic diaphragm. This invention, by designing a double-layered composite elastic diaphragm composed of mound-shaped and flat elastic modules, and ensuring a specific hardness difference of 8-12 HA between the two, can significantly reduce the starting adjustment pressure of the drip irrigation emitter and greatly widen the effective pressure compensation range of the drip irrigation emitter.

Description

Technical Field

[0001] This invention relates to the field of silicone rubber materials technology, specifically to an elastic diaphragm for a pressure-compensating drip irrigation emitter, its preparation method, and its application. Background Technology

[0002] As a core method of efficient water-saving irrigation, the performance of drip irrigation technology largely depends on the stability and reliability of the emitters. Pressure-compensated drip irrigation emitters, due to their ability to maintain a relatively constant flow rate within a certain pressure fluctuation range, significantly improve irrigation uniformity and have become an indispensable key component of modern drip irrigation systems. The pressure compensation function primarily relies on its core component: the elastic diaphragm. The silicone rubber elastic diaphragm of the pressure-compensated emitter achieves automatic flow stabilization through its elastic deformation: when the inlet water pressure rises, the water pressure pushes the diaphragm towards the compensation chamber side, resulting in a decrease in the cross-sectional area of ​​the outlet flow channel or an increase in flow resistance; conversely, when the pressure drops, the diaphragm springs back to its original position, increasing the cross-sectional area of ​​the flow channel or reducing flow resistance. This dynamic balance between deformation and pressure precisely offsets the impact of pressure changes on the flow velocity, thus maintaining a constant flow rate within the system pressure fluctuation range. The entire process requires no external control, relying entirely on the adaptive adjustment of material elasticity and fluid pressure.

[0003] However, in existing technologies, pressure-compensated irrigation systems face two major problems: high initial adjustment pressure and a narrow pressure compensation range. This can be attributed to the poor overall performance of the elastic diaphragm. Due to limitations in material formulation, manufacturing processes, and structural design, existing elastic diaphragms struggle to achieve ideal mechanical properties and dynamic responses to water pressure changes. Specifically, the elastic modulus, hardness, and resilience of traditional diaphragm materials fail to precisely match the water pressure range. This results in a delayed opening action at low pressures, preventing timely and smooth initial deformation to change the flow cross-sectional area, which is the direct cause of the high initial adjustment pressure. Furthermore, as pressure increases, the diaphragm's deformation response exhibits a non-linear relationship with pressure changes due to material properties or structural rigidity limitations. It either reaches its deformation limit prematurely, losing further adjustment capability, or fails to accurately track pressure fluctuations and compensate for flow channel changes in real time due to deformation lag, resulting in a narrow compensation range and poor flow stability. In addition, elastic diaphragms are prone to fatigue aging, permanent deformation or performance degradation under long-term alternating water pressure, which further exacerbates the drift and failure of the compensation characteristics of pressure-compensated water emitters.

[0004] In view of the above-mentioned shortcomings, developing a special silicone rubber elastic diaphragm with excellent mechanical response characteristics and the ability to achieve low starting pressure and wide pressure compensation range has become the key to improving the performance of pressure-compensated emitters and promoting the development of precision drip irrigation technology. Summary of the Invention

[0005] This invention provides an elastic diaphragm for a pressure-compensated drip irrigation emitter, its preparation method, and its application, in order to solve the problems of high starting pressure and small pressure compensation range in existing pressure-compensated drip irrigation emitters.

[0006] In a first aspect, the present invention provides an elastic diaphragm, comprising: a double-layer combined elastic diaphragm composed of a dome-shaped elastic diaphragm and a flat plate-shaped elastic diaphragm;

[0007] The hardness of the mound-shaped elastic diaphragm is 48-58 HA; The hardness of the flat elastic diaphragm is 42-52 HA; The hardness of the mound-shaped elastic diaphragm is 8-12 HA greater than that of the flat elastic diaphragm.

[0008] In one optional embodiment, the double-layer composite elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 49-72 parts; flexibility agent: 3-7 parts; crosslinking agent: 1.9-2.5 parts; antioxidant: 5.35-10.6 parts.

[0009] In one optional embodiment, the mound-shaped elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 59-62.5 parts; flexibility agent: 5.5-6 parts; crosslinking agent: 2.0-2.15 parts; antioxidant: 7.9-8.6 parts; The flat elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 51-56 parts; flexibility agent: 4-5 parts; crosslinking agent: 1.9-1.95 parts; antioxidant: 5.35-7.4 parts.

[0010] In one optional embodiment, the mound-shaped elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 64.5-70 parts; flexibility agent: 6.5-7 parts; crosslinking agent: 2.05-2.2 parts; antioxidant: 9.1-10.1 parts; The flat elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 59-62.5 parts; flexibility agent: 5.5-6 parts; crosslinking agent: 2.0-2.15 parts; antioxidant: 7.9-8.6 parts.

[0011] In one alternative embodiment, the raw silicone rubber comprises methyl vinyl silicone rubber raw rubber; The reinforcing agent includes one or more of silica, silica, and calcium carbonate; The flexibility agent includes dimethyl silicone oil; The crosslinking agent includes a vulcanizing agent and a vulcanizing co-vulcanizing agent; The antioxidants include one or more of iron oxide, antioxidant 1010, antioxidant 168, and light stabilizer 944.

[0012] The methyl vinyl silicone rubber raw material in this invention is manufactured by Dongjue Organosilicon Group Co., Ltd., and its model is 110-1(s). The silica is manufactured by Fujian Wantai Mineral Products Co., Ltd., and its model number is X-2828.

[0013] In one optional embodiment, the vinyl content of the methyl vinyl silicone rubber raw material is 0.07%-0.10%; The vulcanizing agent includes 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; the co-vulcanizing agent includes trimethylolpropane triacrylate; the mass ratio of the vulcanizing agent to the co-vulcanizing agent is 1:0.2-0.3.

[0014] Secondly, the present invention also provides a method for preparing the above-mentioned elastic diaphragm, comprising: weighing raw materials according to the mass fractions of each component, preheating the raw silicone rubber, adding reinforcing agent and flexible agent to the preheated raw silicone rubber in batches and mixing them thoroughly; applying a crosslinking agent to the rubber compound obtained after thorough mixing and performing a first calendering process; mixing an antioxidant with the rubber compound obtained after the first calendering process and performing a second calendering process to obtain raw rubber to be vulcanized; vulcanizing the raw rubber to be vulcanized obtained after calendering and cutting it to obtain an elastic diaphragm for a pressure-compensating drip irrigation emitter.

[0015] In one optional embodiment, the mixing time is 20-25 minutes, the mixing temperature is 30-40°C, and the mixing speed is 20-25 r / min. The temperature of the first rolling mill is 40-45℃, and the time of the first rolling mill is 5-6 minutes; The temperature for the secondary rolling mill is 40-45℃, and the time for the secondary rolling mill is 6-8 minutes.

[0016] In one alternative embodiment, the vulcanization is performed sequentially as a primary vulcanization and a secondary vulcanization.

[0017] Preferably, the vulcanization temperature of the first vulcanization is 170-185℃, and the vulcanization time of the first vulcanization is 9-13 min; Preferably, the vulcanization temperature of the secondary vulcanization is 200-220℃, and the vulcanization time is 1.6-2.0h.

[0018] Thirdly, the present invention also provides the application of the above-described elastic diaphragm or the elastic diaphragm prepared by the above-described preparation method in a pressure-compensating drip irrigation emitter.

[0019] The technical solution of this invention has the following advantages: 1. The present invention provides an elastic diaphragm for a pressure-compensated drip irrigation emitter, comprising: a double-layer composite elastic diaphragm composed of a mound-shaped elastic diaphragm and a flat elastic diaphragm; wherein the hardness of the mound-shaped elastic diaphragm is 48-58 HA; the hardness of the flat elastic diaphragm is 42-52 HA; and the hardness of the flat elastic diaphragm is 8-12 HA greater than that of the mound-shaped elastic diaphragm.

[0020] This invention designs a double-layered elastic diaphragm composed of a dome-shaped elastic diaphragm and a flat elastic module, with a specific hardness difference of 8-12 HA between the two. This significantly reduces the initial adjustment pressure of drip irrigation emitters and greatly expands the effective pressure compensation range. Its working principle is as follows: In the initial stage of drip irrigation system startup, water flow impacts the raised portion of the dome-shaped elastic diaphragm, causing it to preferentially undergo concave deformation. This process preemptively offsets some of the water kinetic energy, preventing premature deformation of the flat elastic diaphragm and thus significantly reducing the initial adjustment pressure. As the inlet water pressure increases, the deformation of the dome-shaped elastic diaphragm intensifies until it contacts the flat elastic diaphragm, where pressure is effectively transmitted. At this point, the difference in the deformation sequence and amplitude caused by the hardness difference between the two allows for stepped and precise control of the outlet cross-sectional area. Under higher pressures, the double-layered elastic diaphragm enters a synergistic deformation state, and its combined stiffness changes non-linearly with pressure, achieving flow stability over a wider pressure range and greatly expanding the effective pressure compensation range.

[0021] 2. This invention provides an elastic diaphragm for a pressure-compensating drip irrigation emitter, its preparation method, and its application. By adding a specific proportion of trimethylolpropane triacrylate (TMPTA) as a co-curing agent, TMPTA, as a multifunctional monomer, effectively promotes an increase in crosslinking density and optimizes the uniformity of the crosslinking network during the curing process. This improvement directly enhances the mechanical properties of the elastic diaphragm, such as higher rebound speed, lower permanent deformation, and excellent tear resistance, thereby ensuring that the performance of the pressure-compensating drip irrigation emitter does not significantly degrade under long-term, frequent deformation operation, and extending its service life.

[0022] 3. This invention uses a composite filler composed of silica, fumed silica, and calcium carbonate in a specific ratio as a reinforcing agent. Under synergistic effect, a stable reinforcing structure is constructed at the molecular level, which significantly improves the elastic modulus, structural strength, and creep resistance of the elastic diaphragm. This allows it to maintain the necessary flexibility to initiate deformation when facing fluctuations in inlet water pressure, while also providing sufficient support to prevent excessive deformation. This ensures that the pressure-compensated drip irrigation emitter maintains high flow stability over a wider pressure range, thereby expanding the pressure compensation range of the pressure-compensated drip irrigation emitter.

[0023] 4. This invention improves the anti-aging performance of elastic diaphragms under complex irrigation water conditions such as brackish water and compound fertilizer water by adding a composite anti-aging agent composed of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 in a specific proportion. It effectively inhibits the hardening, embrittlement and performance degradation of elastic diaphragms, and ensures the stable performance and long-term use of pressure-compensated drip irrigation emitters under harsh working conditions. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating the preparation method of the elastic diaphragm for the pressure-compensating drip irrigation emitter in an embodiment of the present invention. Figure 2 This is a schematic diagram of the upper part of the circular mound-shaped elastic diaphragm in an embodiment of the present invention; Figure 3 This is a schematic diagram of the lower part of the circular mound-shaped elastic diaphragm in an embodiment of the present invention; Figure 4 This is a schematic diagram of a circular flat elastic diaphragm in an embodiment of the present invention; Figure 5 This is a schematic diagram of the combination method and overall structure of a circular combined elastic diaphragm in an embodiment of the present invention; Figure 6 This is a schematic diagram of the upper part of the rectangular mound-shaped elastic diaphragm in an embodiment of the present invention; Figure 7 This is a schematic diagram of the lower part of the rectangular mound-shaped elastic diaphragm in an embodiment of the present invention; Figure 8 This is a schematic diagram of a rectangular flat elastic diaphragm in an embodiment of the present invention; Figure 9 This is a schematic diagram of the combination method and overall structure of a rectangular combined elastic diaphragm in an embodiment of the present invention; Figure 10 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Embodiment 1 of the present invention; Figure 11 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Embodiment 2 of the present invention; Figure 12 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Comparative Example 1 of the present invention; Figure 13 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Comparative Example 2 of the present invention; Figure 14 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Comparative Example 3 of the present invention; Figure 15 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Comparative Example 4 of the present invention; Figure 16 This is a pressure-flow rate curve of the pressure-compensated drip irrigation emitter in Comparative Example 5 of the present invention; Figure 17 This is a comparison chart of the pressure-flow rate relationship curves of the pressure-compensated drip irrigation emitters in Embodiment 1 of the present invention and Comparative Examples 1-5.

[0026] Explanation of reference numerals in the attached figures: 1. The raised portion of a circular mound-shaped elastic diaphragm; 2. The recessed portion of a circular mound-shaped elastic diaphragm; 3. The raised portion of a rectangular mound-shaped elastic diaphragm; 4. The recessed portion of a rectangular mound-shaped elastic diaphragm. Detailed Implementation

[0027] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0028] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0029] The methyl vinyl silicone rubber raw material in this invention is manufactured by Dongjue Organosilicon Group Co., Ltd., and its model is 110-1(s). The silica is manufactured by Fujian Wantai Mineral Products Co., Ltd., and its model number is X-2828.

[0030] Example 1 This embodiment provides an elastic diaphragm for a pressure-compensating drip irrigation emitter and its preparation method, comprising the following raw material components by mass: The circular, mound-shaped elastic membrane comprises: 100 parts of raw silicone rubber; 61 parts of reinforcing agent; 6 parts of flexible agent; 2.15 parts of crosslinking agent; and 8.6 parts of antioxidant.

[0031] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 28 parts silica, and 6.5 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.45 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 8 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The circular, flat, elastic diaphragm comprises: 100 parts of raw silicone rubber; 54 parts of reinforcing agent; 5 parts of flexible agent; 1.9 parts of crosslinking agent; and 6.4 parts of antioxidant.

[0032] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 24 parts silica, 25 parts silica, and 5 parts calcium carbonate; The flexibility agent includes 5 parts of dimethyl silicone oil; The crosslinking agent includes 1.5 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.4 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 6 parts iron oxide, 0.15 parts antioxidant 1010, 0.2 parts antioxidant 168, and 0.05 parts light stabilizer 944; The above-mentioned method for preparing circular, dome-shaped elastic membranes is as follows: Figure 1 The preparation method shown in the flowchart includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Open Milling: Using an open milling machine, preheat the open milling machine to 45 ℃; put the rubber compound obtained in step S2 into the open milling machine and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open milling machine and calender for 7 min. After uniform calendering, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made dome mold, place the mold into the flat vulcanizing machine and preheat it to 175 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175 ℃, the time is 10 min; the flat pressure is 21 MPa, and the air is degassed 3 times; perform the second vulcanization in the secondary vulcanizing box; the vulcanization temperature is 210 ℃, the time is 1.7 h; and obtain the rubber sheet. S5. Cutting and Shaping: Using a circular cutter, cut the film obtained in step S4 into circular mound-shaped elastic film products. The appearance of the circular mound-shaped elastic module products is as follows. Figure 2 and Figure 3 As shown.

[0033] The above-mentioned method for preparing a circular, flat, elastic diaphragm is as follows: Figure 1 The preparation method shown in the flowchart includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 30°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 30 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Milling: Using an open-type rubber mill, preheat the open-type rubber mill to 40 ℃; put the rubber compound obtained in step S2 into the open-type rubber mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open-type rubber mill and calender for 6 min. After uniform milling, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made flat mold, place the mold in the flat vulcanizing machine and preheat it to 170 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 170 ℃, the time is 9 min; the flat pressure is 20 MPa, and the air is depressurized 3 times; perform the second vulcanization in the second vulcanizing box; the vulcanization temperature is 200 ℃, the time is 1.6 h; and obtain the rubber sheet. S5. Cutting and Shaping: Using a circular cutter, cut the film obtained in step S4 into a circular, flat, elastic film product. The appearance of the circular, flat, elastic film product is as follows: Figure 4 As shown.

[0034] In this embodiment, a Shore A hardness tester is used to measure the hardness of the elastic diaphragm according to the national standard GB / T 531.1-2008 "Test Method for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber Part 1: Shore Hardness Tester Method (Shore Hardness)". In this embodiment, the hardness of the circular flat elastic diaphragm is 42HA, and the hardness of the circular mound elastic diaphragm is 50HA. The concave sides of the circular flat elastic diaphragm and the circular mound elastic diaphragm are attached to obtain a circular combined pressure-compensating drip irrigation emitter elastic diaphragm, the appearance of which is as follows. Figure 5 As shown; place the circular combined elastic diaphragm with the raised side facing the inlet of the pressure-compensating drip irrigation emitter into the pressure-compensating drip irrigation emitter.

[0035] Example 2 This embodiment provides a circular pressure-compensating drip irrigation device elastic diaphragm and its preparation method, comprising the following raw material components by mass: The rectangular mound-shaped elastic membrane comprises: 100 parts of raw silicone rubber; 67.5 parts of reinforcing agent; 7 parts of flexible agent; 2.2 parts of crosslinking agent; and 9.6 parts of antioxidant.

[0036] Among them, the raw silicone rubber includes 100 parts of methyl vinyl silicone rubber; The reinforcing agent consists of 28 parts silica, 32 parts silica, and 7.5 parts calcium carbonate; The flexibility agent includes 7 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.5 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethylperoxy)sulfurizing agent, and the trimethylolpropane triacrylate is the co-sulfurizing agent. The antioxidants include: 9 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The rectangular flat elastic diaphragm comprises: 100 parts of raw silicone rubber; 60.5 parts of reinforcing agent; 6 parts of flexible agent; 2.1 parts of crosslinking agent; and 8.1 parts of antioxidant.

[0037] Among them, the raw silicone rubber includes 100 parts of methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 27 parts silica, and 7 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (i.e., bis(2,5-dimethyl)sulfide) and 0.4 parts of trimethylolpropane triacrylate (TMPTA). The antioxidants include: 7.5 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The method for preparing the above-mentioned rectangular mound-shaped elastic membrane includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 40°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 40 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 5 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Open Mixing: Using an open mixing mill, preheat the open mixing mill to 45°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 2 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 6 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 8 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made dome mold, place the mold into the flat vulcanizing machine and preheat it to 185°C; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 180°C and the time is 13 min; the flat pressure is 22 MPa, and the air is depressurized 4 times; perform the second vulcanization in the secondary vulcanizing box; the vulcanization temperature is 220°C and the time is 2.0 h; to obtain the rubber sheet; S5. Cutting and Shaping: Using a rectangular cutter, cut the film obtained in step S4 into rectangular mound-shaped elastic film products. The appearance of the rectangular mound-shaped elastic film products is as follows: Figure 6 and Figure 7 As shown.

[0038] The method for preparing the above-mentioned rectangular flat elastic diaphragm includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Mixing: Using an open mixing mill, preheat the open mixing mill to 45°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 7 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made flat mold, place the mold in the flat vulcanizing machine and preheat it to 175°C; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175°C, the time is 10 min; the flat pressure is 21 MPa, and the air is depressurized 3 times; perform the second vulcanization in the second vulcanizing box; the vulcanization temperature is 210°C, the time is 1.7 h; and obtain the rubber sheet. S5. Cutting and Shaping: Using a rectangular cutter, cut the film obtained in step S4 into rectangular flat elastic film products. The appearance of the rectangular flat elastic film products is as follows: Figure 8 As shown.

[0039] The rectangular flat elastic diaphragm has a hardness of 49 HA, and the rectangular mound elastic diaphragm has a hardness of 58 HA. By bonding the rectangular flat elastic diaphragm and the rectangular mound elastic diaphragm together on their concave sides, a rectangular combined pressure-compensating drip irrigation emitter elastic diaphragm is obtained, with the appearance as shown below. Figure 9 As shown; place the rectangular combined elastic diaphragm with the raised side facing the inlet of the pressure-compensating drip irrigation emitter into the pressure-compensating drip irrigation emitter.

[0040] Comparative Example 1 This comparative example provides an elastic diaphragm for a pressure-compensating drip irrigation emitter and its preparation method, comprising the following raw material components by mass: The circular mound-shaped elastic diaphragm and the circular flat plate-shaped elastic diaphragm each comprise: 100 parts of raw silicone rubber; 61 parts of reinforcing agent; 6 parts of flexible agent; 2.15 parts of crosslinking agent; and 8.6 parts of antioxidant.

[0041] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 28 parts silica, and 6.5 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.45 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 8 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The method for preparing the above-mentioned circular elastic diaphragm includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Open Milling: Using an open milling machine, preheat the open milling machine to 45 ℃; put the rubber compound obtained in step S2 into the open milling machine and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open milling machine and calender for 7 min. After uniform calendering, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made dome mold, place the mold in the flat vulcanizing machine and preheat it to 175 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175 ℃, the time is 10 min; the flat pressure is 21 MPa, and the air is depressurized 3 times; perform the second vulcanization in the second vulcanizing box; the vulcanization temperature is 210 ℃, the time is 1.7 h; to obtain a rubber sheet; for circular flat elastic diaphragm sheets, replace the mold with a specially made flat mold; S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into circular mound-shaped / flat elastic film products.

[0042] The hardness of the flat elastic diaphragm is 51 HA, and the hardness of the mound elastic diaphragm is 52 HA. The concave side of the circular flat elastic diaphragm and the circular mound elastic diaphragm are attached to obtain a circular combined pressure-compensating drip irrigation diaphragm. The raised side of the circular combined elastic diaphragm is placed towards the inlet of the pressure-compensating drip irrigation diaphragm and then placed into the pressure-compensating drip irrigation diaphragm.

[0043] Comparative Example 2 This comparative example provides an elastic diaphragm for a pressure-compensating drip irrigation emitter and its preparation method, comprising the following raw material components by mass: The circular, mound-shaped elastic membrane comprises: 100 parts of raw silicone rubber; 74 parts of reinforcing agent; 8.5 parts of flexible agent; 2.4 parts of crosslinking agent; and 10.9 parts of antioxidant.

[0044] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 30 parts silica, 36 parts silica, and 8 parts calcium carbonate; The flexibility agent includes 8.5 parts of dimethyl silicone oil; The crosslinking agent includes 1.8 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.6 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethylperoxy)sulfurizing agent, and the trimethylolpropane triacrylate is the co-sulfurizing agent. The antioxidants include: 10 parts iron oxide, 0.3 parts antioxidant 1010, 0.4 parts antioxidant 168, and 0.2 parts light stabilizer 944; The circular, flat, elastic diaphragm comprises: 100 parts of raw silicone rubber; 61 parts of reinforcing agent; 6 parts of flexible agent; 2.15 parts of crosslinking agent; and 8.6 parts of antioxidant.

[0045] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 28 parts silica, and 6.5 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.45 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 8 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The method for preparing the above-mentioned circular mound-shaped elastic membrane includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Mixing: Using an open mixing mill, preheat the open mixing mill to 45°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 7 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made dome mold, place the mold into the flat vulcanizing machine and preheat it to 190°C; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 190°C and the time is 12 min; the flat pressure is 22 MPa, and the air is depressurized 3 times; perform the second vulcanization in the second vulcanizing box; the vulcanization temperature is 230°C and the time is 1.8 h; to obtain the rubber sheet; S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into a circular mound-shaped elastic film product.

[0046] The method for preparing the above-mentioned circular flat elastic diaphragm includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Mixing: Using an open mixing mill, preheat the open mixing mill to 45°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 7 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made flat mold, place the mold in the flat vulcanizing machine and preheat it to 175°C; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175°C and the time is 10 min; the flat pressure is 21 MPa, and the air is depressurized 3 times; perform the second vulcanization in the second vulcanizing box; the vulcanization temperature is 210°C and the time is 1.7 h; to obtain the rubber sheet; S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into a circular flat elastic film product.

[0047] The circular flat elastic diaphragm has a hardness of 49 HA, and the circular mound elastic diaphragm has a hardness of 63 HA. The concave side of the circular flat elastic diaphragm and the circular mound elastic diaphragm are attached together to obtain a circular combined pressure-compensating drip irrigation diaphragm. The raised side of the circular combined elastic diaphragm is placed in the pressure-compensating drip irrigation diaphragm with the inlet facing the water inlet.

[0048] Comparative Example 3 This comparative example provides an elastic diaphragm for a pressure-compensating drip irrigation emitter and its preparation method, comprising the following raw material components by mass: The circular, mound-shaped elastic membrane comprises: 100 parts of raw silicone rubber; 61 parts of reinforcing agent; 6 parts of flexible agent; 2.15 parts of crosslinking agent; and 8.6 parts of antioxidant.

[0049] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 28 parts silica, and 6.5 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.45 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 8 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The circular, flat, elastic diaphragm comprises: 100 parts of raw silicone rubber; 50 parts of reinforcing agent; 4 parts of flexible agent; 1.9 parts of crosslinking agent; and 5.35 parts of antioxidant.

[0050] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 23 parts silica, 23 parts silica, and 4 parts calcium carbonate; The flexibility agent includes 4 parts of dimethyl silicone oil; The crosslinking agent includes 1.5 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.4 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 5 parts iron oxide, 0.1 parts antioxidant 1010, 0.2 parts antioxidant 168, and 0.05 parts light stabilizer 944; The method for preparing the above-mentioned circular mound-shaped elastic membrane includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Mixing: Using an open mixing mill, preheat the open mixing mill to 45°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 7 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made dome mold, place the mold into the flat vulcanizing machine and preheat it to 175 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175 ℃, the time is 10 min; the flat pressure is 21 MPa, and the air is degassed 3 times; perform the second vulcanization in the secondary vulcanizing box; the vulcanization temperature is 210 ℃, the time is 1.7 h; and obtain the rubber sheet. S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into a circular mound-shaped elastic film product.

[0051] The method for preparing the above-mentioned circular flat elastic diaphragm includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 30°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 30 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Mixing: Using an open mixing mill, preheat the open mixing mill to 40°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 6 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made flat mold, place the mold in the flat vulcanizing machine and preheat it to 165 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 165 ℃, the time is 9 min; the flat pressure is 20 MPa, and the air is depressurized 3 times; perform the second vulcanization in the secondary vulcanizing box; the vulcanization temperature is 200 ℃, the time is 1.6 h; and obtain the rubber sheet. S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into a circular flat elastic film product.

[0052] The circular flat elastic diaphragm has a hardness of 44 HA, and the circular mound elastic diaphragm has a hardness of 50 HA. The concave sides of the circular flat elastic diaphragm and the circular mound elastic diaphragm are attached to obtain a circular combined pressure-compensating drip irrigation diaphragm. The raised side of the circular combined elastic diaphragm is placed in the pressure-compensating drip irrigation diaphragm with the inlet facing the diaphragm.

[0053] Comparative Example 4 This comparative example provides an elastic diaphragm for a pressure-compensating drip irrigation emitter and its preparation method, comprising the following raw material components by mass: The circular, mound-shaped elastic membrane comprises: 100 parts of raw silicone rubber; 61 parts of reinforcing agent; 6 parts of flexible agent; 2.15 parts of crosslinking agent; and 8.6 parts of antioxidant.

[0054] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 28 parts silica, and 6.5 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.45 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 8 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The method for preparing the above-mentioned circular mound-shaped elastic membrane includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Open Milling: Using an open milling machine, preheat the open milling machine to 45 ℃; put the rubber compound obtained in step S2 into the open milling machine and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open milling machine and calender for 7 min. After uniform calendering, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made dome mold, place the mold into the flat vulcanizing machine and preheat it to 175 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175 ℃, the time is 10 min; the flat pressure is 21 MPa, and the air is degassed 3 times; perform the second vulcanization in the secondary vulcanizing box; the vulcanization temperature is 210 ℃, the time is 1.7 h; and obtain the rubber sheet. S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into a circular mound-shaped elastic film product.

[0055] The hardness of the circular dome-shaped elastic diaphragm is 50 HA. Place the single-layer circular dome-shaped diaphragm with the raised surface facing the inlet of the pressure-compensating drip irrigation emitter and insert it into the pressure-compensating drip irrigation emitter.

[0056] Comparative Example 5 This comparative example provides an elastic diaphragm for a pressure-compensating drip irrigation emitter and its preparation method, comprising the following raw material components by mass: The circular, flat, elastic diaphragm comprises: 100 parts of raw silicone rubber; 61 parts of reinforcing agent; 6 parts of flexible agent; 2.15 parts of crosslinking agent; and 8.6 parts of antioxidant.

[0057] Among them, the raw silicone rubber includes 100 parts of raw methyl vinyl silicone rubber; The reinforcing agent consists of 26.5 parts silica, 28 parts silica, and 6.5 parts calcium carbonate; The flexibility agent includes 6 parts of dimethyl silicone oil; The crosslinking agent includes 1.7 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.45 parts of trimethylolpropane triacrylate (TMPTA). The 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is the bis(2,5-dimethyl)peroxy)hexane, and the trimethylolpropane triacrylate is the co-vulcanizing agent. The antioxidants include: 8 parts iron oxide, 0.2 parts antioxidant 1010, 0.3 parts antioxidant 168, and 0.1 parts light stabilizer 944; The method for preparing the above-mentioned circular flat elastic diaphragm includes the following steps: S1. Raw material preparation: Weigh the corresponding weight of the raw materials according to the determined mass fractions of each component. S2. Mixing and internal mixing: Using an internal mixer, preheat the internal mixer to 35°C; put the raw methyl vinyl silicone rubber weighed in step S1 into the internal mixer and stir for 35 seconds. After the silicone rubber is preheated, adjust the stirring speed of the internal mixer to 20 r / min. Add the mixture of silica, silica, calcium carbonate and dimethyl silicone oil into the internal mixer in four batches, one batch every 4 minutes. After mixing evenly, the rubber compound is obtained. S3, Calendering and Mixing: Using an open mixing mill, preheat the open mixing mill to 45°C; put the rubber compound obtained in step S2 into the open mixing mill and calender for 1 min; spread the mixture of bis(2,5) vulcanizing agent and TMPTA from step S1 evenly onto the rubber compound, adjust the gap between the two rolls to 4 mm, and calender for 5 min; put the mixture of iron oxide, antioxidant 1010, antioxidant 168 and light stabilizer 944 from step S1 into the open mixing mill and calender for 7 min. After uniform mixing, the raw rubber to be vulcanized is obtained. S4. Vulcanization Molding: Using a flat vulcanizing machine and a specially made flat mold, place the mold in the flat vulcanizing machine and preheat it to 175 ℃; place the raw rubber to be vulcanized obtained in step S3 into the mold; perform the first vulcanization in the flat vulcanizing machine; the vulcanization temperature is 175 ℃, the time is 10 min; the flat pressure is 21 MPa, and the air is depressurized 3 times; perform the second vulcanization in the secondary vulcanizing box; the vulcanization temperature is 210 ℃, the time is 1.7 h; and obtain the rubber sheet. S5. Cutting and shaping: Using a circular cutter, cut the film obtained in step S4 into a circular flat elastic film product.

[0058] The circular flat elastic diaphragm has a hardness of 49 HA. Place the single-layer circular flat diaphragm with any side facing the inlet of the pressure-compensating drip irrigation emitter and put it into the pressure-compensating drip irrigation emitter.

[0059] Experimental Example 1 1. The flow rates of the pressure-compensated drip irrigation emitters prepared in Examples 1-2 and Comparative Examples 1-5 were obtained according to the national standard GB / T 19812.2-2017 "Plastic Water-Saving Irrigation Equipment Part 2: Pressure Compensating Drip Emitters and Drip Irrigation Pipes" under test conditions with inlet water pressure of 10-450 kPa. The results are shown in Table 1.

[0060] Table 1:

[0061] Figure 10 and Figure 11 The figures shown are pressure-flow rate curves for the pressure-compensated drip irrigation emitters in Embodiments 1 and 2 of the present invention. Figure 12 , Figure 13 , Figure 14 , Figure 15 and Figure 16 These are pressure-flow rate curves of the pressure-compensated drip irrigation emitters in Comparative Examples 1, 2, 3, 4, and 5 of this invention. Figure 17 This is a comparison chart of the pressure-flow rate relationship curves of the pressure-compensated drip irrigation emitters in Embodiment 1 of the present invention and Comparative Examples 1-5.

[0062] According to Table 1 and Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 , Figure 15 , Figure 16 and Figure 17 The content of this application determines the starting pressure and compensation range of the pressure-compensated drip irrigation emitters obtained in Examples 1-2 and Comparative Examples 1-5. The method for determining the starting pressure and compensation range in this application is as follows: the obvious inflection point (the pressure at which the flow rate of the drip irrigation emitter begins to remain constant) on the pressure-flow relationship curve of the drip irrigation emitter is taken as the starting pressure of the compensation range of the emitter, and the smooth flow section after the starting pressure is the pressure compensation range of the emitter.

[0063] Table 2:

[0064] A comparison of the data from Examples 1-2 and Comparative Examples 1-5 in Tables 1 and 2 shows that the elastic diaphragm for the pressure-compensating drip irrigation emitter prepared in Example 1 of this application can reduce the starting pressure of the pressure-compensating drip irrigation emitter to 35 kPa and widen the pressure compensation range to 35-350 kPa. The difference between Comparative Example 1 and Example 1 is that the combined elastic diaphragm in Comparative Example 1 does not have a significant hardness difference, while the starting pressure of Comparative Example 1 is 70 kPa and the pressure compensation range is 70-310 kPa. That is, by setting a hardness difference of 8-12 HA, this invention unexpectedly and significantly reduces the starting pressure and widens the pressure compensation range. The combined elastic diaphragms of Comparative Examples 2-3 all outperformed the single-layer mound-shaped elastic diaphragm of Comparative Example 4 or the single-layer plate-shaped elastic diaphragm of Comparative Example 5. That is, the double-layer combined elastic diaphragm of the present invention can achieve the effect of reducing the starting pressure and widening the compensation range in terms of structure. Furthermore, by setting a hardness difference of 8-12HA between the mound-shaped elastic diaphragm and the plate-shaped elastic diaphragm, the effect brought by the double-layer combined structure is greatly amplified, which effectively reduces the starting pressure of the pressure-compensated drip irrigation emitter, greatly increases the pressure compensation range, and significantly improves the hydraulic performance.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An elastic diaphragm, characterized in that, include: A double-layered elastic diaphragm composed of a dome-shaped elastic diaphragm and a flat elastic diaphragm; The hardness of the mound-shaped elastic diaphragm is 48-58 HA; The hardness of the flat elastic diaphragm is 42-52 HA; The hardness of the mound-shaped elastic diaphragm is 8-12 HA greater than that of the flat elastic diaphragm.

2. The elastic diaphragm according to claim 1, characterized in that, The double-layer composite elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 49-72 parts; flexibility agent: 3-7 parts; crosslinking agent: 1.9-2.5 parts; antioxidant: 5.35-10.6 parts.

3. The elastic diaphragm according to claim 2, characterized in that, The mound-shaped elastic membrane comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 59-62.5 parts; flexibility agent: 5.5-6 parts; crosslinking agent: 2.0-2.15 parts; antioxidant: 7.9-8.6 parts; The flat elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 51-56 parts; flexibility agent: 4-5 parts; crosslinking agent: 1.9-1.95 parts; antioxidant: 5.35-7.4 parts.

4. The elastic diaphragm according to claim 2, characterized in that, The mound-shaped elastic membrane comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 64.5-70 parts; flexibility agent: 6.5-7 parts; crosslinking agent: 2.05-2.2 parts; antioxidant: 9.1-10.1 parts; The flat elastic diaphragm comprises, by weight, the following raw material components: Silicone raw rubber: 100 parts; reinforcing agent: 59-62.5 parts; flexibility agent: 5.5-6 parts; crosslinking agent: 2.0-2.15 parts; antioxidant: 7.9-8.6 parts.

5. The elastic diaphragm according to any one of claims 2-4, characterized in that, The raw silicone rubber includes raw methyl vinyl silicone rubber; And / or, the reinforcing agent includes one or more of silica, silica, and calcium carbonate; And / or, the flexibility agent comprises dimethyl silicone oil; And / or, the crosslinking agent includes a vulcanizing agent and a co-vulcanizing agent; And / or, the antioxidant includes one or more of iron oxide, antioxidant 1010, antioxidant 168, and light stabilizer 944.

6. The elastic diaphragm according to claim 5, characterized in that, The vinyl content of the methyl vinyl silicone rubber raw material is 0.07%-0.10%; And / or, the vulcanizing agent comprises 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; the co-vulcanizing agent comprises trimethylolpropane triacrylate; the mass ratio of the vulcanizing agent to the co-vulcanizing agent is 1:0.2-0.

3.

7. A method for preparing an elastic diaphragm as described in any one of claims 1-6, characterized in that, include: After weighing the raw materials according to the mass fractions of each component, the raw silicone rubber is preheated. Reinforcing agents and flexibility agents are added to the preheated raw silicone rubber in batches and then mixed intensively. The crosslinking agent is applied to the rubber compound obtained after intensive mixing and then calendered for the first time. The antioxidant is mixed with the rubber compound obtained after the first calendering and then calendered for the second time to obtain the raw rubber to be vulcanized. The raw rubber to be vulcanized after calendering is vulcanized and then cut to obtain the elastic diaphragm of the pressure-compensating drip irrigation emitter.

8. The preparation method according to claim 7, characterized in that, The mixing time is 20-25 min, the mixing temperature is 30-40℃, and the mixing speed is 20-25 r / min; And / or, the temperature of the first rolling mill is 40-45℃, and the time of the first rolling mill is 5-6 minutes; And / or, the temperature of the secondary rolling mill is 40-45℃, and the time of the secondary rolling mill is 6-8 minutes.

9. The preparation method according to claim 7, characterized in that, The vulcanization process involves a primary vulcanization and a secondary vulcanization. Preferably, the vulcanization temperature of the first vulcanization is 170-185℃, and the vulcanization time of the first vulcanization is 9-13 min; Preferably, the vulcanization temperature of the secondary vulcanization is 200-220℃, and the vulcanization time is 1.6-2.0h.

10. The application of an elastic diaphragm as described in any one of claims 1-6 or an elastic diaphragm prepared by any one of claims 7-9 in a pressure-compensated drip irrigation system.

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