A rubber composition for duckbill valve inner layer rubber and preparation method thereof

Abstract

The present invention provides a rubber composition for inner layer rubber of duckbill valve and a preparation method thereof, belonging to the technical field of rubber products, and solves the technical problems of import control, high price, and after-sales service that cannot be guaranteed in existing imported duckbill valves. The rubber composition is prepared from the following components in parts by weight: 100 parts of chloroprene rubber, 30-60 parts of reinforcing agent, 0.2-1.5 parts of silane coupling agent, 8-20 parts of barium sulfate, 8-20 parts of operating oil, 0.5-2 parts of antioxidant, 3-10 parts of plasticizer, 1-5 parts of zinc oxide, 2-6 parts of magnesium oxide, 0.5-2 parts of stearic acid, 0.5-2.5 parts of accelerator, and 1-2 parts of vulcanizing agent. After the above raw materials are mixed according to parts by weight, they are prepared by a segmented multi-stage mixing process. The present invention has the advantages of being able to give full play to the performance advantages of chloroprene rubber and high vinyl polybutadiene rubber, the rubber composition after mixing can be stored for a long time, and it is not easy to produce blooming and scorching during processing.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber products, and relates to a rubber composition and a preparation method thereof, in particular to a rubber composition used for an inner layer rubber of a duckbill valve and a preparation method thereof. Background Art

[0002] The duckbill valve is a flexible check valve made of rubber and shaped like a duckbill. When the pressure inside the valve is greater than the pressure outside the valve to a certain extent, the pressure inside the valve forces the duckbill valve to open and allow water to flow through; when the pressure outside the valve exceeds the pressure inside the valve by a certain value, the duckbill valve closes to prevent backflow. The duckbill valve has the advantages of being easy to use, not easy to damage, low resistance, tight closure without water leakage, and no noise. It is the best facility to prevent backflow of river channels.

[0003] At present, duckbill valves have been successfully applied in large project construction, and their excellent anti-backflow performance has been fully recognized by the user units. In the structure of duckbill valves, the inner layer rubber is an important part of producing duckbill valve products with excellent performance. The wear resistance and corrosion resistance of the inner layer rubber materials used to produce duckbill valves in the prior art cannot meet the expected standards, and frosting and scorching are prone to occur in the production process of the inner layer rubber. In order to solve the above problems, the present invention provides a rubber composition and a preparation method thereof to meet the domestic performance requirements for duckbill valves. Summary of the invention

[0004] The purpose of the present invention is to address the above-mentioned problems in the existing technology and to propose a rubber composition for the inner layer rubber of a duckbill valve and a preparation method thereof. The technical problem to be solved by the invention is: how to improve the overall performance of the rubber duckbill valve product and increase its service life.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An object of the present invention is to provide a rubber composition for the inner layer rubber of a duckbill valve, wherein the composition is prepared from the following materials in parts by weight: 100 parts of chloroprene rubber, 30-60 parts of a reinforcing agent, 0.2-1.5 parts of a silane coupling agent, 8-20 parts of barium sulfate, 8-20 parts of an operating oil, 0.5-2 parts of an antioxidant, 3-10 parts of a plasticizer, 1-5 parts of zinc oxide, 2-6 parts of magnesium oxide, 0.5-2 parts of stearic acid, 0.5-2.5 parts of an accelerator, 1-2 parts of a vulcanizing agent, and 5-15 parts of high vinyl polybutadiene rubber (HVBR).

[0007] The reinforcing agent is one or more of N600 series carbon black, N700 series carbon black and N700 series white carbon black, and the accelerator is two or three of tetramethylthiuram disulfide TMTD, 2,2'-dibenzothiazole disulfide DM and N-tert-butyl-2-benzothiazole sulfenamide NS.

[0008] The plasticizer is dioctyl phthalate (DOP), and the vulcanizing agent is sulfur or dicumyl peroxide (DCP).

[0009] The process oil is naphthenic oil.

[0010] The antioxidant is a non-polluting amine antioxidant KY405 or 2-mercaptobenzimidazole MB.

[0011] Another object of the present invention is to provide a method for preparing the rubber composition for the inner layer of the duckbill valve, using a segmented multi-stage mixing process, and the specific preparation process is as follows:

[0012] S1. Add chloroprene rubber, high vinyl polybutadiene rubber (HVBR), and magnesium oxide to an internal mixer in sequence, and continue to add stearic acid, antioxidant, and barium sulfate after mixing evenly, and mix according to a standard rubber mixing process to obtain a masterbatch;

[0013] S2, further mixing the first-stage masterbatch, reinforcing agent and plasticizer in an internal mixer, and then sequentially adding silane coupling agent and operating oil, and mixing evenly to obtain the second-stage masterbatch;

[0014] S3, mix the second-stage masterbatch and accelerator ingredients on an open mixer, adjust the roller distance according to the accumulation of rubber, and mix them thoroughly;

[0015] S4. After the raw materials are fully mixed and spread, thin rolls are made, zinc oxide is added, and after sufficient mixing, the quality of the rubber material is checked and thin rolls are made into sheets;

[0016] S5, adding a vulcanizing agent to mix evenly, placing it aside, and then feeding it into a vulcanization mold, vulcanizing the final rubber mix on a flat vulcanizer, and then unrolling the sheet, inspecting the rubber material, and obtaining a rubber composition.

[0017] The equipment used in the steps S1-S5 is a rubber composition preparation equipment for the inner layer rubber of the duckbill valve, including an internal mixer, an open mixer, and a vulcanizer. The output end of the internal mixer is connected to the input end of the open mixer through an extrusion assembly. The extrusion assembly includes an extrusion barrel, the input end of the extrusion barrel is fixedly connected to the output end of the internal mixer, and an extrusion screw is rotatably connected in the extrusion barrel, and a driving motor is fixed in the extrusion barrel, the output shaft of the driving motor is coaxially fixedly connected to the extrusion screw, the output end of the extrusion barrel is connected to the input end of the open mixer, a mixing chamber is provided in the open mixer, and a pair of A mixing roller, an adjusting component for controlling the distance between two mixing rollers is arranged in the open mixing mill, the vulcanizer comprises a conveying frame and a top frame, four regulating screws are rotatably connected between the conveying frame and the top frame, four regulating motors are fixedly connected in the top frame, the output shafts of the four regulating motors are all coaxially fixedly connected with the corresponding regulating screws, an upper mold is threadedly connected between the four regulating screws, a lower mold is slidably connected on the conveying frame, a regulating component for controlling the movement of the lower mold is arranged in the conveying frame, the output end of the open mixing mill is located directly above the die groove of the lower mold, a discharging component is arranged in the lower mold, and a heating element is built into the upper mold.

[0018] With the above structure, chloroprene rubber, high vinyl polybutadiene rubber (HVBR), and magnesium oxide can be added into an internal mixer, and then the raw materials are preliminarily mixed by the internal mixer. After the mixing is uniform, stearic acid, antioxidant and barium sulfate are added, and the mixing is carried out according to the standard rubber mixing process to obtain a first-stage masterbatch. At this time, the first-stage masterbatch, reinforcing agent and plasticizer are mixed in proportion for secondary mixing. During the mixing process, silane coupling agent and operating oil are added in sequence. After uniform mixing, a second-stage masterbatch is obtained, and then the second-stage masterbatch is transported to an open mixer for secondary mixing. During the transportation process, the extrusion screw is driven by a driving motor to rotate, and the raw materials are further sheared and extruded, thereby improving the mixing effect of the raw materials and the mixing efficiency. The spacing between the two mixing rollers is controlled by adjusting the components, so that the roller spacing can be adjusted according to the accumulation of rubber during the mixing process. , further improve the mixing efficiency and reduce the friction between the raw materials, so as to stabilize the temperature and reduce the phenomenon of "over-plasticization" caused by excessive plasticity during the mixing process. After the raw materials are fully mixed and dispersed, they are thinly rolled and zinc oxide is added. After sufficient mixing, the quality of the rubber compound is inspected, and then the mixed raw materials are transported into the mold groove of the lower mold, and then the lower mold is driven to move to the bottom of the upper mold through the regulating component. At this time, the regulating motor drives the regulating screw to rotate, and the regulating screw is connected to the thread of the upper mold to drive the upper mold to press down, so that the upper mold and the lower mold are combined to vulcanize the raw materials inside. When the vulcanization is completed, the upper mold is lifted, and then the lower mold is moved out of the pressing position, and the vulcanized composition is separated from the mold groove through the discharging component, which is convenient for personnel to collect and improve the overall preparation efficiency.

[0019] The adjustment component includes a rotating plate rotatably connected to the cavity walls on both sides of the top and bottom of the mixing cavity, a pair of guide slots on the two rotating plates, each of which is slidably connected to a guide slider, each of which is fixed with a blocking plate for blocking the corresponding guide slot, both ends of the two mixing rollers are rotatably connected to the corresponding blocking plates, an adjustment box is rotatably connected in the open mill, the adjustment box is coaxially fixedly connected to one of the rotating plates, and a control motor is fixed in the open mill, and the output shaft of the control motor is coaxially fixedly connected to the other rotating plate. A gear tower is rotatably connected in the regulating box. The gear tower is composed of multiple gears that are overlapped in sequence from large to small and are fixedly connected to each other on the same axis. An output motor is fixed in the regulating box. The output shaft of the output motor is coaxially fixedly connected to the gear tower. A pair of meshing gears are meshed on the gear tower, and a cross rod is coaxially fixed on the two meshing gears. A stabilizing rod is provided on each cross rod. A sleeve rod is rotatably connected in the two stabilizing rods. A cross slide is provided in each sleeve rod. The cross slide is slidably connected to the cross rod, and the top of each sleeve rod is connected to the corresponding mixing The refining rollers are coaxially fixedly connected, the top of each stabilizing rod is fixedly connected to the corresponding guide slider, and a push spring is fixed between each cross rod and the bottom of the corresponding cross slide, a pair of winding gears are fixed in the adjusting box, a winding wheel is coaxially fixed on each winding gear, each winding wheel is fixedly connected to one end of a traction rope, the other end of the traction rope is fixedly connected to the corresponding stabilizing rod, and the other end of each traction rope is sleeved with a reset spring, one end of the reset spring is fixedly connected to the inner wall of the adjusting box, and the other end of the reset spring is sleeved with a reset spring. One end is fixedly connected to the corresponding stabilizer bar surface, an outer gear ring is rotatably connected in the adjustment box, the outer gear ring is meshed with two winding gears, and a servo motor 1 is fixed to the adjustment box, the output shaft of the servo motor 1 is coaxially fixedly connected to one of the winding gears, a push block is slidably connected in the adjustment box, and a pair of servo motors 2 are rotatably connected in the adjustment box, the output ends of the two servo motors 2 are coaxially fixed with push screws, the two push screws are threadedly connected to the push blocks, and the top surface of the push block is matched with the two meshing gears for pushing.

[0020] With the above structure, two meshing gears can be meshed with gears of different sizes on the gear tower, thereby changing the spacing between the two meshing gears, and further changing the spacing between the two mixing rollers, and when the servo motor drives one of the winding gears to rotate, one of the winding gears will drive the other winding gear to rotate through the gear ring, and when both winding gears rotate, they will drive the corresponding winding wheels to rotate, and when the winding wheels rotate, they will pull the two stabilizing bars to move through the traction rope, so that the two meshing gears slide down and mesh with the larger gears on the next layer of the gear tower, which can be achieved by The traction rope continuously pulls the stabilizer bar to move, thereby continuously increasing the distance between the two mixing rollers. When the distance between the two mixing rollers needs to be reduced, the servo motor 2 can be used to drive the push screw to rotate. After the push screw rotates, it will drive the push block to lift, and the push block will further push the two winding gears to lift. At this time, the winding wheel is rotated in the opposite direction to release the traction rope, so that the return spring pushes the two stabilizer bars to slide, so that the meshing gear can mesh with the smaller gear on the upper layer, thereby reducing the distance between the two mixing rollers, thereby realizing controllable adjustment of the mixing roller distance.

[0021] The regulating component includes a conveying screw rotatably connected to the conveying frame and a servo motor three fixed in the conveying frame. The output shaft of the servo motor three is coaxially fixedly connected to the conveying screw, and the lower mold is threadedly connected to the conveying screw.

[0022] With the above structure, the servo motor can drive the conveying screw to rotate. After the conveying screw rotates, it will drive the lower mold to move, thereby realizing the ability to receive raw materials and transport them to the processing area for vulcanization treatment, thereby improving the overall operating efficiency.

[0023] The discharging assembly includes a discharging plate arranged in the die groove of the lower mold, and two pairs of worm gears are rotatably connected in the lower mold, and two worm screws are rotatably connected in the lower mold, and each worm gear is meshed with a corresponding pair of worm gears, and a lifting screw is coaxially fixedly connected to the two pairs of worm gears, and a lifting sleeve is threadedly connected to each lifting screw, and the top of each lifting sleeve is fixedly connected to the bottom surface of the discharging plate, and a docking seat is rotatably connected outside the lower mold, and plug-in grooves are provided on the two docking seats, one end of the two worm screws is coaxially fixedly connected to the corresponding plug-in seats, and a pair of regulating gears are rotatably connected in the conveying frame, and the two regulating gears are coaxially fixedly connected with sockets, and plug-in blocks are fixed on the two sockets, and the plug-in blocks are plug-matched with the corresponding plug-in grooves, and the two regulating gears are connected with transmission toothed belts, and a servo motor four is fixed in the conveying frame, and the output shaft of the servo motor four is coaxially fixedly connected to one of the regulating gears.

[0024] By adopting the above structure, the lower mold can be moved to the socket and the receiving seat for plugging and matching, so that at this time the servo motor four drives one of the regulating gears to rotate, and after one of the regulating gears rotates, it will drive the other regulating gear to rotate synchronously through the transmission belt, and after both regulating gears rotate, they will drive the two sockets to rotate, because the socket and the receiving seat are plug-in matched, thereby driving the receiving seat to rotate, and after the receiving seat rotates, it will drive the corresponding worm to rotate, and after the worm rotates, it will drive the corresponding worm wheel to rotate, and after the worm wheel rotates, it will drive the lifting screw to rotate, and after the lifting screw rotates, it will drive the lifting sleeve to lift, so that the feed plate is ejected, and the discharge plate further realizes the discharge action, so that the ejection composition is separated from the mold groove, and it is convenient for personnel to collect it, thereby improving the overall preparation efficiency.

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

[0026] 1. In the rubber composition of the present invention, not only by adding appropriate mass parts of chloroprene rubber and high vinyl polybutadiene rubber with a glass transition temperature, but also by selecting white carbon black with a certain specific surface area, the interfacial compatibility of the solution-polymerized chloroprene rubber and polybutadiene rubber blend can be synergistically improved from multiple angles, and the anti-corrosion, high wear resistance and high tensile resistance of the rubber composition can be well achieved. The rubber composition is applied to the preparation of the inner layer rubber of the duckbill valve, and the high wear resistance, high tensile resistance and corrosion resistance performance requirements of the duckbill valve are met.

[0027] 2. According to the characteristics of chloroprene rubber and high vinyl polybutadiene rubber, the mixing process of the rubber composition is designed in sections, which not only ensures the uniformity of the dispersion of the rubber, but also can give full play to the performance advantages of chloroprene rubber and high vinyl polybutadiene rubber. The mixed rubber composition can be stored for a long time, and it is not easy to produce frosting and scorching during the processing.

[0028] 3. The distance between the two mixing rollers is controlled by adjusting the components. During the mixing process, the roller distance is adjusted according to the accumulation of rubber, which further improves the mixing efficiency and reduces the friction between the raw materials, thereby stabilizing the temperature and reducing the phenomenon of "over-plasticization" caused by excessive plasticity during the mixing process.

[0029] 4. The regulating motor drives the regulating screw to rotate, and the regulating screw is connected to the upper mold through a thread, driving the upper mold to press down, so that the upper mold and the lower mold are combined to vulcanize the raw materials inside. When the vulcanization is completed, the upper mold is lifted, and then the lower mold is moved out of the pressing position, and the vulcanized composition is separated from the ejection groove through the discharge assembly, which is convenient for personnel to collect and improve the overall preparation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a process flow chart of the present invention.

[0031] Figure 2 It is a performance test table of the rubber compound prepared by the present invention.

[0032] Figure 3 This is a test table of the performance of the rubber compound under the influence of different proportions of the silane coupling agent in the present invention.

[0033] Figure 4 This is a test table of the performance of the rubber material under the influence of different proportions of barium sulfate in the present invention.

[0034] Figure 5 This is a test table of rubber properties under the influence of different proportions of high vinyl polybutadiene rubber in the present invention.

[0035] Figure 6 It is a structural schematic diagram of a rubber composition preparation device for the inner layer rubber of a duckbill valve in the present invention.

[0036] Figure 7 It is a schematic diagram of the structure inside the mixing mill of the present invention.

[0037] Figure 8 It is a schematic diagram of the three-dimensional structure inside the regulating box of the present invention.

[0038] Fig. 9 It is a schematic diagram of the structure inside the stabilizer bar of the present invention.

[0039] Fig.10 It is a schematic structural diagram of the mixing roller in the present invention in a retracted state.

[0040] Fig.11 It is a structural schematic diagram of the mixing roller in the present invention in an unfolded state.

[0041] Fig.12 It is a schematic diagram of the planar structure inside the regulating box of the present invention.

[0042] Fig.13 It is a schematic diagram of the structure inside the vulcanizer of the present invention.

[0043] Fig.14 It is a schematic diagram of the planar structure of the discharging assembly in the present invention.

[0044] Fig.15 It is a three-dimensional structural schematic diagram of the discharging assembly in the present invention.

[0045] Fig.16 It is a partially enlarged schematic diagram of the internal structure of the mixing mill in the present invention.

[0046] In the figure, 1, internal mixer; 2, open mixer; 3, vulcanizer; 4, extruder; 5, extruder screw; 6, drive motor; 7, mixing chamber; 8, mixing roller; 9, conveyor frame; 10, top frame; 11, regulating screw; 12, regulating motor; 13, upper mold; 14, lower mold; 15, rotating plate; 16, guide chute; 17, guide slide; 18, blocking plate; 19, regulating box; 20, control motor; 21, gear tower; 22, output motor; 23, meshing gear; 24, cross rod; 25, stabilizer rod; 26, sleeve rod; 27, Cross slide; 28. Push spring; 29. ​​Winding gear; 30. Winding wheel; 31. Traction rope; 32. Reset spring; 33. Outer gear ring; 34. Servo motor one; 35. Push block; 36. Servo motor two; 37. Push screw; 38. Conveying screw; 39. Servo motor three; 40. Discharge plate; 41. Worm gear; 42. Worm; 43. Lifting screw; 44. Lifting sleeve; 45. Connector; 46. Plug-in slot; 47. Adjusting gear; 48. Socket; 49. Plug-in block; 50. Transmission belt; 51. Servo motor four. DETAILED DESCRIPTION

[0047] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0048] Example 1

[0049] The rubber composition for the inner layer rubber of a duckbill valve provided by the present invention is prepared from the following components in parts by weight: 100 parts of chloroprene rubber, 45 parts of a reinforcing agent, 14 parts of an operating oil, 1.25 parts of an antioxidant KY405, 3 parts of zinc oxide, 1.25 parts of stearic acid; 1.5 parts of an accelerator; 1.5 parts of a vulcanizing agent; 6.5 parts of a plasticizer; 0.2 parts of a silane coupling agent; 14 parts of barium sulfate; 4 parts of magnesium oxide; and 10 parts of high vinyl polybutadiene rubber (HVBR).

[0050] Among them, the reinforcing agent is N600 carbon black, the operating oil is cyclohexane oil, the plasticizer is dioctyl phthalate (DOP), the vulcanizing agent is sulfur, the antioxidant is the non-polluting amine antioxidant KY405, and the accelerator is a mixture of tetramethylthiuram disulfide TMTD and NS.

[0051] like Figure 1 As shown, the above raw materials are prepared according to the following preparation process:

[0052] (1) According to the raw material ratio, chloroprene rubber, high vinyl polybutadiene rubber (HVBR), and magnesium oxide are added to an internal mixer in sequence, and after mixing evenly, stearic acid, an antioxidant, and barium sulfate are added, and mixing is performed according to a standard rubber mixing process to obtain a masterbatch;

[0053] (2) The first-stage masterbatch, reinforcing agent and plasticizer are mixed in proportion, further mixed in an internal mixer, and then the silane coupling agent and operating oil are added in sequence, and mixed evenly to obtain the second-stage masterbatch;

[0054] (3) Mix the second-stage masterbatch and accelerator in the above proportions, mix them on an open mixer, adjust the roller distance according to the accumulation of rubber, and mix them thoroughly;

[0055] (4) After the raw materials are fully mixed and dispersed, thin rolls are made, zinc oxide is added, and after sufficient mixing, the quality of the rubber material is checked and thin rolls are made into sheets;

[0056] (5) Add the vulcanizing agent and mix evenly. After standing, send it into the vulcanization mold, vulcanize the final rubber on a flat vulcanizer, then take it off the sheet, inspect the rubber material, and obtain the rubber composition.

[0057] In the above preparation process, the process is designed in sections, which not only ensures the uniformity of the dispersion of the rubber material, but also can give full play to the performance advantages of chloroprene rubber and high vinyl polybutadiene rubber. The equipment used in the process is innovatively improved to make it less likely to produce frosting and scorching during the processing.

[0058] like Figure 6-Figure 16 As shown, the equipment used in steps S1-S5 is a rubber composition preparation equipment for the inner layer rubber of the duckbill valve, including an internal mixer 1, an open mixer 2, and a vulcanizer 3. The output end of the internal mixer 1 is connected to the input end of the open mixer 2 through an extrusion assembly. The extrusion assembly includes an extrusion barrel 4. The input end of the extrusion barrel 4 is fixedly connected to the output end of the internal mixer 1, and an extrusion screw 5 is rotatably connected in the extrusion barrel 4. A drive motor 6 is fixed in the extrusion barrel 4, and the output shaft of the drive motor 6 is coaxially fixedly connected to the extrusion screw 5. The output end of the extrusion barrel 4 is connected to the input end of the open mixer 2. A mixing chamber 7 is provided in the open mixer 2. A pair of mixing rollers 8 are rotatably provided in the mixing chamber. The open mixer 2 An adjusting component for controlling the distance between the two mixing rollers 8 is arranged inside, the vulcanizer 3 includes a conveying frame 9 and a top frame 10, four adjusting screws 11 are rotatably connected between the conveying frame 9 and the top frame 10, four adjusting motors 12 are fixedly connected inside the top frame 10, the output shafts of the four adjusting motors 12 are coaxially fixedly connected with the corresponding adjusting screws 11, an upper mold 13 is threadedly connected between the four adjusting screws 11, a lower mold 14 is slidably connected to the conveying frame 9, an adjusting component for controlling the movement of the lower mold 14 is arranged inside the conveying frame 9, the output end of the open mixing mill 2 is located directly above the die groove of the lower mold 14, a discharging component is arranged inside the lower mold 14, and a heating element is built into the upper mold 13.

[0059] With the above structure, chloroprene rubber, high vinyl polybutadiene rubber (HVBR), and magnesium oxide are added into an internal mixer 1, and then the raw materials are preliminarily mixed by the internal mixer 1. After the mixing is uniform, stearic acid, antioxidant and barium sulfate are continuously added, and the mixing is carried out according to the standard rubber mixing process to obtain a first-stage masterbatch. At this time, the first-stage masterbatch, reinforcing agent and plasticizer are mixed in proportion for secondary mixing. During the mixing process, silane coupling agent and operating oil are added in sequence. After uniform mixing, a second-stage masterbatch is obtained, and then the second-stage masterbatch is transported to an open mixer 2 for secondary mixing. During the transportation process, the extrusion screw 5 is driven to rotate by a driving motor 6 to further shear and extrude the raw materials, thereby improving the mixing effect of the raw materials and the mixing efficiency. The spacing between the two mixing rollers 8 is controlled by an adjusting component, so that during the mixing process, the roller spacing is adjusted according to the accumulation of rubber, and the mixing efficiency is further improved. , and reduce the friction between the raw materials, so as to stabilize the temperature and reduce the phenomenon of "over-plasticization" caused by excessive plasticity during the mixing process. After the raw materials are fully mixed and dispersed, thin rolls are made, zinc oxide is added, and after sufficient mixing, the quality of the rubber compound is inspected, and then the mixed raw materials are transported into the die groove of the lower mold 14, and then the lower mold 14 is driven by the regulating component to move to the bottom of the upper mold 13. At this time, the regulating motor 12 drives the regulating screw 11 to rotate, and the regulating screw 11 is connected to the threaded connection with the upper mold 13 to drive the upper mold 13 to press down, so that the upper mold 13 is combined with the lower mold 14 to vulcanize the raw materials inside. When the vulcanization is completed, the upper mold 13 is lifted, and the lower mold 14 is moved out of the pressing position, and the vulcanized composition is separated from the die groove through the discharging component, which is convenient for personnel to collect and improve the overall preparation efficiency.

[0060] The adjustment component includes a rotating plate 15 rotatably connected to the cavity walls on both sides of the top and bottom of the mixing chamber 7, a pair of guide slots 16 are provided on the two rotating plates 15, each of the guide slots 16 is slidably connected with a guide slider 17, each guide slider 17 is fixed with a blocking plate 18 for blocking the corresponding guide slot 16, both ends of the two mixing rollers 8 are rotatably connected to the corresponding blocking plates 18, an adjustment box 19 is rotatably connected in the open mill 2, the adjustment box 19 is coaxially fixedly connected to one of the rotating plates 15, and a control motor 20 is fixed in the open mill 2, the output shaft of the control motor 20 is coaxially fixedly connected to the other rotating plate 15, and the adjusting box 19 is fixed in the open mill 2. The gear tower 21 is rotatably connected, and the gear tower 21 is composed of a plurality of gears overlapping in sequence from large to small and fixedly connected to each other on the same axis, and an output motor 22 is fixed in the regulating box 19, and the output shaft of the output motor 22 is coaxially fixedly connected to the gear tower 21, and a pair of meshing gears 23 are meshed on the gear tower 21, and a cross rod 24 is coaxially fixed on the two meshing gears 23, and each cross rod 24 is provided with a stabilizing rod 25, and a sleeve rod 26 is rotatably connected in the two stabilizing rods 25, and a cross slide 27 is provided in each sleeve rod 26, and the cross slide 27 is slidably connected to the cross rod 24, and the top of each sleeve rod 26 is rotatably connected to the corresponding mixing The roller 8 is coaxially fixedly connected, the top of each stabilizing rod 25 is fixedly connected to the corresponding guide slider 17, and a pushing spring 28 is fixed between each cross rod 24 and the bottom of the corresponding cross slide 27, a pair of winding gears 29 are fixed in the adjusting box 19, and a winding wheel 30 is coaxially fixed on each winding gear 29, each winding wheel 30 is fixedly connected to one end of a traction rope 31, and the other end of the traction rope 31 is fixedly connected to the corresponding stabilizing rod 25, and the other end of each traction rope 31 is sleeved with a reset spring 32, one end of the reset spring 32 is fixedly connected to the inner wall of the adjusting box 19, and the other end of the reset spring 32 is sleeved with a reset spring 32. One end is fixedly connected to the corresponding surface of the stabilizer bar 25, an outer ring gear 33 is rotatably connected in the adjustment box 19, the outer ring gear 33 is meshed with the two winding gears 29, and a servo motor 1 34 is fixed to the adjustment box 19, the output shaft of the servo motor 1 34 is coaxially fixedly connected to one of the winding gears 29, a push block 35 is slidably connected in the adjustment box 19, and a pair of servo motors 2 36 are rotatably connected in the adjustment box 19, the output ends of the two servo motors 2 36 are coaxially fixed with push screws 37, the two push screws 37 are threadedly connected to the push block 35, and the top surface of the push block 35 is matched with the two meshing gears 23 for pushing.

[0061] With the above structure, the two meshing gears 23 can mesh with gears of different sizes on the gear tower 21, thereby changing the spacing between the two meshing gears 23, and further changing the spacing between the two mixing rollers 8, and driving one of the winding gears 29 to rotate through the servo motor 34, and one of the winding gears 29 will drive the other winding gear 29 to rotate through the gear ring, and after both winding gears 29 rotate, they will drive the corresponding winding wheel 30 to rotate, and after the winding wheel 30 rotates, it will pull the two stabilizing bars 25 to move through the traction rope 31, so that the two meshing gears 23 slide down and mesh with the larger gears of the next layer of the gear tower 21, and the traction rope 31 can be used to pull the two stabilizing bars 25 to move, so that the two meshing gears 23 can slide down and mesh with the larger gears of the next layer of the gear tower 21. The rope 31 continuously pulls the stabilizing rod 25 to move, thereby continuously increasing the distance between the two mixing rollers 8. When the distance between the two mixing rollers 8 needs to be reduced, the servo motor 2 36 can be used to drive the pushing screw 37 to rotate. After the pushing screw 37 rotates, it will drive the pushing block 35 to lift up, and the pushing block 35 will further push the two winding gears 29 to lift up. At this time, the winding wheel 30 is rotated in the opposite direction, so that the winding wheel 30 releases the traction rope 31, and the reset spring 32 pushes the two stabilizing rods 25 to slide, so that the meshing gear 23 can mesh with the smaller gear on the upper layer, so as to reduce the distance between the two mixing rollers 8, thereby realizing controllable adjustment of the distance between the mixing rollers 8.

[0062] The regulating component includes a conveying screw 38 rotatably connected to the conveying frame 9 and a servo motor 39 fixed in the conveying frame 9. The output shaft of the servo motor 39 is coaxially fixedly connected to the conveying screw 38, and the lower mold 14 is threadedly connected to the conveying screw 38.

[0063] With the above structure, the servo motor 39 can be used to drive the conveying screw 38 to rotate. After the conveying screw 38 rotates, it will drive the lower mold 14 to move, thereby realizing the ability to receive raw materials and transport them to the processing area for vulcanization treatment, thereby improving the overall operating efficiency.

[0064] The discharge assembly includes a discharge plate 40 arranged in the die groove of the lower mold 14, and two pairs of worm gears 41 are rotatably connected in the lower mold 14, and two worms 42 are rotatably connected in the lower mold 14, each worm gear 41 is meshed with a corresponding pair of worm gears 41, and the two pairs of worm gears 41 are coaxially fixedly connected with a lifting screw 43, and each lifting screw 43 is threadedly connected with a lifting sleeve 44, and the top of each lifting sleeve 44 is fixedly connected to the bottom surface of the discharge plate 40, and a docking seat 45 is rotatably connected to the outside of the lower mold 14, and the two docking seats 45 are provided with A plug-in slot 46, one end of the two worm gears 42 are coaxially fixedly connected to the corresponding plug-in seat 45, and a pair of regulating gears 47 are rotatably connected in the conveying frame 9, and the two regulating gears 47 are coaxially fixedly connected with a socket 48, and the two sockets 48 are fixed with a plug-in block 49, the plug-in block 49 is plugged with the corresponding plug-in slot 46, and the two regulating gears 47 are connected with a transmission belt 50, and a servo motor four 51 is fixed in the conveying frame 9, and the output shaft of the servo motor four 51 is coaxially fixedly connected to one of the regulating gears 47.

[0065] By adopting the above structure, the lower mold 14 can be moved to the socket 48 to be plugged into the receiving seat 45, so that the servo motor 451 can drive one of the regulating gears 47 to rotate. After one of the regulating gears 47 rotates, it will drive the other regulating gear 47 to rotate synchronously through the transmission belt 50. After both regulating gears 47 rotate, they will drive the two sockets 48 to rotate. Since the sockets 48 and the receiving seat 45 are plugged into and matched, the receiving seat 45 is driven to rotate. After the receiving seat 45 rotates, it will drive the corresponding worm 42 to rotate. After the worm 42 rotates, it will drive the corresponding worm wheel 41 to rotate. After the worm wheel 41 rotates, it will drive the lifting screw 43 to rotate. After the lifting screw 43 rotates, it will drive the lifting sleeve 44 to lift, so that the feed plate 40 is ejected, and the discharge plate 40 further realizes the discharge action, so that the ejected composition is separated from the mold groove, and it is convenient for personnel to collect it, thereby improving the overall preparation efficiency.

[0066] Example 2

[0067] The technical feature that distinguishes Example 2 of the present invention from Example 1 is that the weight portion of the silane coupling agent is 0.85 parts.

[0068] Example 3

[0069] The technical feature that distinguishes Example 3 of the present invention from Example 1 is that the weight portion of the silane coupling agent is 1.5 parts.

[0070] Comparative Example 1

[0071] The technical feature that the comparative example 1 is different from the embodiment 1 is that the weight portion of the silane coupling agent is 0.

[0072] Example 4

[0073] The technical feature that distinguishes Example 4 of the present invention from Example 1 is that the weight portion of barium sulfate is 8 parts.

[0074] Example 5

[0075] The technical feature that distinguishes Example 5 of the present invention from Example 1 is that the weight portion of barium sulfate is 20 parts.

[0076] Comparative Example 2

[0077] The technical feature of the comparison example 2 that is different from the example 1 is that the weight portion of barium sulfate is 0 part.

[0078] Example 6

[0079] The technical feature that distinguishes Example 6 of the present invention from Example 1 is that the weight portion of high vinyl polybutadiene rubber (HVBR) is 5 parts.

[0080] Example 7

[0081] The technical feature that distinguishes Example 7 of the present invention from Example 1 is that the weight portion of high vinyl polybutadiene rubber (HVBR) is 15 parts.

[0082] Comparative Example 3

[0083] The technical feature of Comparative Example 3 that is different from Example 1 is that the weight portion of high vinyl polybutadiene rubber (HVBR) is 0 parts.

[0084] Example 8

[0085] The technical feature that distinguishes Example 8 of the present invention from Example 1 is that the equipment used in the preparation are all processing equipment that can be purchased on the existing market.

[0086] Performance Testing:

[0087] The following national standards were used to test the properties of the rubber materials prepared in the above examples and comparative examples. Figure 2 The specific inspection and testing standards are as follows:

[0088] 1. After the rubber to be tested is vulcanized at 150°C for 30 minutes, its performance is tested in accordance with the national standard GB / T6038-2006; and it is aged with hot air at 100°C for 24 hours, and its performance is tested in accordance with the national standard GB / T3512-2014;

[0089] 2. The hardness of the rubber material is tested according to the national standard GB / T531.1-2008;

[0090] 3. The 300% elongation stress, tensile strength, elongation at break and permanent deformation performance of the rubber material are tested according to the national standard GB / T528-2009;

[0091] 4. The tear strength of the rubber is tested according to the national standard GB / T529-2008;

[0092] 5. The resilience of the rubber material is tested according to the national standard GB / T1681-2009;

[0093] 6. The compression fatigue temperature rise performance of the rubber material is tested according to the national standard GB / T1687.3-2016;

[0094] 7. The brittle temperature index of the rubber compound is tested according to the national standard GB / T1682-2014.

[0095] right Figure 2 The results of the performance tests of the rubber materials prepared in Examples 1 to 3 and Comparative Example 1 are as follows: Figure 3 shown.

[0096] pass Figure 3 It can be seen from the performance test data of Examples 1-3 and Comparative Example 1 that the amount of silane coupling agent added will have a significant impact on the performance of the rubber. When the silane coupling is within the range of the number of additions given in the present invention, the comprehensive performance of the obtained product is excellent, and the performance of the rubber can be significantly improved; when no silane coupling agent is added in the comparative example, the hardness of the rubber is basically unchanged, but the tensile stress, tensile strength, elongation at break, tear strength, resilience, fatigue temperature rise and other properties are significantly reduced. This is because the silane coupling agent can couple the components through molecular bonds, effectively improve the molecular bonding of the rubber, and then improve the heat resistance and deformation rate of the rubber; if the content of the silane coupling agent is too little, the components cannot be effectively coupled, resulting in reduced heat resistance and deformation rate.

[0097] right Figure 2 The results of the performance tests of the rubber materials prepared in Example 2, Examples 4-5 and Comparative Example 2 are as follows: Figure 4 shown.

[0098] pass Figure 4It can be seen from the performance test data in Example 2, Examples 4-5 and Comparative Example 2 that the addition of barium sulfate will have a significant impact on the performance of the rubber. When the amount of barium sulfate added is within the range of the number of portions given in the present invention, the comprehensive performance of the obtained product is excellent, and the performance of the rubber can be significantly improved; when barium sulfate is not added in the comparative example, the hardness and resilience of the rubber do not change much, but the hardness, tensile stress, tensile strength, and tear strength performances are significantly reduced, while the compression fatigue temperature rise and elongation at break are significantly enhanced. This is because barium sulfate can increase the hardness of the material, effectively improve the hardness of the rubber, and adjust the deformation rate of the rubber; if the content of barium sulfate is too large, the brittleness of the rubber becomes stronger, and it is impossible to carry out later processing and shaping.

[0099] right Figure 2 The results of the performance tests of the rubber materials prepared in Example 2, Examples 6-8 and Comparative Example 3 are as follows: Figure 5 shown.

[0100] pass Figure 5 It can be seen from the performance test data in Example 2, Examples 6-8 and Comparative Example 3 that the addition amount of high vinyl polybutadiene rubber will have a significant impact on the performance of the rubber compound. When the high vinyl polybutadiene rubber is within the range of the addition amount given in the present invention, the comprehensive performance of the obtained product is excellent, and the performance of the rubber compound can be significantly improved. The present invention adds high vinyl polybutadiene rubber (HVBR) to significantly improve the elongation at break performance of the rubber compound after vulcanization and hot air aging, and its 300% tensile stress and tensile strength are also significantly improved after hot air aging. This is because the polymer bonds in HVBR and the polymer bonds of the main material are fused to form more complex polymer bonding bonds, so that the formed rubber compound has better properties such as heat resistance and acid and alkali corrosion resistance, and the polymer also has greater elasticity during the stretching process, so that the rubber compound has better tensile properties and stronger tensile stress characteristics, and the use of the rubber composition preparation equipment in the present invention can improve the tensile properties and stronger tensile stress characteristics of the rubber compound, and the elongation at break performance is significantly improved, which significantly improves the performance of the rubber compound.

[0101] It can be seen from the above embodiments and comparative examples that the innovation of the rubber composition of the present invention lies in the innovative addition of a specific proportion of ingredients, including silane coupling agent, barium sulfate, magnesium oxide, and high vinyl polybutadiene rubber (HVBR), to the existing rubber material. Through the interaction between the above ingredients and the main material, the rubber composition can exert various excellent effects such as better strength and stress as well as resistance to high temperature and pressure. If the above main influencing ingredients are changed, the performance of the rubber compound will be significantly reduced. Therefore, under the specific components of the present invention, it can be well used in the preparation materials of duckbill valves to meet the technical requirements of duckbill valves for manufacturing materials.

[0102] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for preparing a rubber composition for an inner layer of a duckbill valve, characterized in that: The multi-stage mixing process is adopted, and the specific preparation process is as follows: S1, add chloroprene rubber, high vinyl polybutadiene rubber, and magnesium oxide to an internal mixer in sequence, and continue to add stearic acid, antioxidant, and barium sulfate after mixing evenly, and mix according to a standard rubber mixing process to obtain a masterbatch; S2, mixing the first-stage masterbatch, reinforcing agent and plasticizer in an internal mixer, and then sequentially adding silane coupling agent and operating oil, and mixing evenly to obtain the second-stage masterbatch; S3, mix the second-stage masterbatch and accelerator ingredients on an open mixer, adjust the roller distance according to the accumulation of rubber, and mix them thoroughly; S4. After the raw materials are fully mixed and spread, thin rolls are made, zinc oxide is added, and after sufficient mixing, the quality of the rubber material is checked and thin rolls are made into sheets; S5, adding a vulcanizing agent to mix evenly, feeding it into a vulcanization mold after parking, vulcanizing the final rubber on a flat vulcanizing press, then unrolling, inspecting the rubber material, and obtaining a rubber composition; The equipment used in the steps S1-S5 is a rubber composition preparation equipment for the inner layer rubber of the duckbill valve, comprising an internal mixer (1), an open mixer (2), and a vulcanizer (3), wherein the output end of the internal mixer (1) is connected to the input end of the open mixer (2) via an extrusion assembly, wherein the extrusion assembly comprises an extrusion barrel (4), wherein the input end of the extrusion barrel (4) is fixedly connected to the output end of the internal mixer (1), and an extrusion screw (5) is rotatably connected inside the extrusion barrel (4), and a drive motor (6) is fixed inside the extrusion barrel (4), wherein the output shaft of the drive motor (6) is coaxially fixedly connected to the extrusion screw (5), the output end of the extrusion barrel (4) is connected to the input end of the open mixer (2), a mixing chamber (7) is provided inside the open mixer (2), a pair of mixing rollers (8) are rotatably provided inside the mixing chamber, and a mixing roller (9) is provided inside the open mixer (2) An adjusting component for controlling the distance between two mixing rollers (8) is arranged. The vulcanizer (3) comprises a conveying frame (9) and a top frame (10). Four adjusting screws (11) are rotatably connected between the conveying frame (9) and the top frame (10). Four adjusting motors (12) are fixedly connected inside the top frame (10). The output shafts of the four adjusting motors (12) are coaxially fixedly connected to the corresponding adjusting screws (11). An upper mold (13) is threadedly connected between the four adjusting screws (11). A lower mold (14) is slidably connected to the conveying frame (9). An adjusting component for controlling the movement of the lower mold (14) is arranged inside the conveying frame (9). The output end of the open mill (2) is located directly above the die groove of the lower mold (14). A discharging component is arranged inside the lower mold (14). A heating element is built into the upper mold (13). The adjustment component comprises a rotating plate (15) rotatably connected to the cavity walls on both sides of the top and bottom of the mixing cavity (7), a pair of guide slots (16) provided on the two rotating plates (15), each of the guide slots (16) being slidably connected with a guide slider (17), each of the guide sliders (17) being fixed with a blocking plate (18) for blocking the corresponding guide slot (16), both ends of the two mixing rollers (8) being rotatably connected to the corresponding blocking plates (18), an adjustment box (19) being rotatably connected in the open mill (2), the adjustment box (19) being coaxially fixedly connected to one of the rotating plates (15), and a control motor (20) being fixed in the open mill (2), the output shaft of the control motor (20) being coaxially fixed to the other rotating plate (15) The adjusting box (19) is connected with a gear tower (21) in rotation, and the gear tower (21) is composed of a plurality of gears stacked in order from large to small and fixedly connected to each other on the same axis. An output motor (22) is fixedly connected to the adjusting box (19), and the output shaft of the output motor (22) is coaxially fixedly connected to the gear tower (21). A pair of meshing gears (23) are meshed on the gear tower (21), and a cross rod (24) is coaxially fixed on the two meshing gears (23). A stabilizing rod (25) is provided on each cross rod (24), and sleeve rods (26) are rotatably connected to the two stabilizing rods (25). A cross slot (27) is provided in each sleeve rod (26), and the cross slot (27) is slidably connected to the cross rod (24), and each sleeve rod (26) is provided with a cross slot (27). The top of each rod (26) is coaxially fixedly connected to the corresponding mixing roller (8), the top of each stabilizing rod (25) is fixedly connected to the corresponding guide slider (17), and a push spring (28) is fixed between each cross rod (24) and the bottom of the corresponding cross slide (27), a pair of winding gears (29) are fixed in the regulating box (19), and a winding wheel (30) is coaxially fixed on each winding gear (29), each winding wheel (30) is fixedly connected to one end of a traction rope (31), and the other end of the traction rope (31) is fixedly connected to the corresponding stabilizing rod (25), and the other end of each traction rope (31) is sleeved with a return spring (32), and one end of the return spring (32) is connected to the regulating box (19). 9) is fixedly connected to the inner wall, the other end of the return spring (32) is fixedly connected to the surface of the corresponding stabilizing rod (25), an outer gear ring (33) is rotatably connected in the regulating box (19), the outer gear ring (33) is meshed with the two winding gears (29), and a servo motor 1 (34) is fixed in the regulating box (19), the output shaft of the servo motor 1 (34) is coaxially fixedly connected to one of the winding gears (29), a push block (35) is slidably connected in the regulating box (19), and a pair of servo motors 2 (36) are rotatably connected in the regulating box (19), the output ends of the two servo motors 2 (36) are coaxially fixed with push screws (37), and the two push screws (37) are threadedly connected to the push block (35),The top surface of the push block (35) is push-fitted with the two meshing gears (23).

2. The method for preparing the rubber composition for the inner layer of the duckbill valve according to claim 1, characterized in that: The regulating assembly comprises a conveying screw (38) rotatably connected to the conveying frame (9), and a servo motor three (39) fixed in the conveying frame (9); the output shaft of the servo motor three (39) is coaxially fixedly connected to the conveying screw (38), and the lower mold (14) is threadedly connected to the conveying screw (38).

3. The method for preparing the rubber composition for the inner layer of the duckbill valve according to claim 1, characterized in that: The discharge assembly comprises a discharge plate (40) arranged in the die groove of the lower mold (14), and two pairs of worm gears (41) are rotatably connected in the lower mold (14), and two worms (42) are rotatably connected in the lower mold (14), and each worm gear (41) is meshed with a corresponding pair of worm gears (41), and the two pairs of worm gears (41) are coaxially fixedly connected with a lifting screw (43), and each lifting screw (43) is threadedly connected with a lifting sleeve (44), and the top of each lifting sleeve (44) is fixedly connected to the bottom surface of the discharge plate (40), and a docking seat (45) is rotatably connected outside the lower mold (14), and the two docking seats (45) are provided with A plug-in slot (46) is provided, one end of each of the two worm gears (42) is coaxially fixedly connected to a corresponding plug-in seat (45), and a pair of regulating gears (47) are rotatably connected in the conveying frame (9), the two regulating gears (47) are coaxially fixedly connected to a socket (48), the two sockets (48) are fixed with a plug-in block (49), the plug-in block (49) is plugged and matched with the corresponding plug-in slot (46), and the two regulating gears (47) are connected with a transmission toothed belt (50), and a servo motor four (51) is fixed in the conveying frame (9), and the output shaft of the servo motor four (51) is coaxially fixedly connected to one of the regulating gears (47).

4. A rubber composition prepared by the method for preparing a rubber composition for an inner layer of a duckbill valve according to any one of claims 1 to 3, characterized in that: The composition is prepared from the following materials in parts by weight: 100 parts of chloroprene rubber, 30-60 parts of a reinforcing agent, 0.2-1.5 parts of a silane coupling agent, 8-20 parts of barium sulfate, 8-20 parts of an operating oil, 0.5-2 parts of an antioxidant, 3-10 parts of a plasticizer, 1-5 parts of zinc oxide, 2-6 parts of magnesium oxide, 0.5-2 parts of stearic acid, 0.5-2.5 parts of an accelerator, 1-2 parts of a vulcanizing agent, and 5-15 parts of high vinyl polybutadiene rubber.

5. The rubber composition for the inner layer of a duckbill valve according to claim 4, characterized in that: The reinforcing agent is one or more of N600 series carbon black, N700 series carbon black and N700 series white carbon black, and the accelerator is two or three of tetramethylthiuram disulfide TMTD, 2,2'-dibenzothiazole disulfide DM and N-tert-butyl-2-benzothiazole sulfenamide NS.

6. The rubber composition for the inner layer of a duckbill valve according to claim 4, characterized in that: The plasticizer is dioctyl phthalate, and the vulcanizing agent is sulfur or dicumyl peroxide.

7. The rubber composition for the inner layer of a duckbill valve according to claim 4, characterized in that: The process oil is naphthenic oil.

8. The rubber composition for the inner layer of a duckbill valve according to claim 4, characterized in that: The antioxidant is a non-polluting amine antioxidant KY405 or 2-mercaptobenzimidazole.

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