Rubber composition for duckbill valve cord fabric rubber as well as preparation method and application of rubber composition

Abstract

The invention provides a rubber composition for duckbilled valve cord fabric rubber as well as a preparation method and application thereof, belongs to the technical field of rubber products, and solves the technical problems that bubbles formed in first-stage mixing of existing masterbatch continue to enter second-stage mixing, so that the bubbles are difficult to defoam, the performance of the rubber products is reduced and the like. The rubber composition is prepared from rubber, a reinforcing agent, zinc oxide, stearic acid, a vulcanizing agent, an accelerant, operating oil, resorcinol, an adhesive and molybdenum polybutadiene rubber (CVBR) according to the mass part ratio, and the rubber is prepared by combining natural rubber and butadiene-styrene rubber through a two-stage process. The preparation process disclosed by the invention has the advantages of improving the performance and quality of the rubber mixture finished product and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber products, and relates to a rubber composition, a preparation method and an application thereof, in particular to a rubber composition for duckbill valve cord rubber, a preparation method and an application 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 is easy to use, not easy to damage, has low resistance, closes tightly without leaking, and has no noise. It is the best facility to prevent backflow of river channels. The duckbill valve is usually installed at the end of the pipeline or at the intersection of urban sewage branch lines. Choosing the right rubber material is crucial to the performance and service life of the duckbill valve.

[0003] After searching, for example, Chinese patent documents disclose a method for preparing a tire tread rubber composition and a rubber composition [Application number: CN202111624052.2; Publication number: CN114213728B]. The method for preparing the tire tread rubber composition and the rubber composition limit the amount and proportion of the thiol protective agent and the thiol deblocking agent, add the thiol protective agent in the first masterbatch mixing, and add the thiol deblocking agent in the second masterbatch mixing, which can flexibly optimize and balance the use properties such as rolling resistance and wear resistance of the rubber and the processing properties such as Mooney viscosity and self-adhesion according to different formula characteristics and requirements.

[0004] Although the preparation method of the tire tread rubber composition and the rubber composition disclosed in the patent improve the wear resistance in tire applications, bubbles may be generated in the rubber mixture after mixing due to the action of water in the compounding ingredients. The masterbatch formed by the preparation method of the tire tread rubber composition and the rubber composition after mixing is directly subjected to two-stage mixing. The bubbles formed by the masterbatch in the first stage of mixing continue to enter the second stage of mixing, making it difficult to defoam the bubbles, thereby reducing the performance of the rubber product. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the prior art and to propose a rubber composition for duckbill valve cord rubber and a preparation method and application thereof. The technical problem to be solved by the invention is: how to improve the performance and quality of the finished rubber mixture product.

[0006] The purpose of the present invention can be achieved by the following technical solutions: An object of the present invention is to provide a rubber composition for duckbill valve cord rubber, which is composed of the following raw materials in parts by mass: 100 parts of rubber, 30-80 parts of reinforcing agent, 1-5 parts of zinc oxide, 0.5-3 parts of stearic acid, 1-3.5 parts of vulcanizing agent, 0.5-2 parts of accelerator, 2-8 parts of operating oil, 0.5-2.5 parts of resorcinol, 1-4 parts of adhesive, and 5-15 parts of molybdenum-based polybutadiene rubber (CVBR).

[0007] Preferably, the rubber composition is composed of the following raw materials in parts by mass: 100 parts of rubber, 70 parts of reinforcing agent, 1 part of zinc oxide, 1 part of stearic acid, 3 parts of vulcanizing agent, 1.2 parts of accelerator, 6 parts of process oil, 1.5 parts of resorcinol, 2.5 parts of adhesive, and 10 parts of molybdenum-based polybutadiene rubber (CVBR).

[0008] Preferably, the rubber is a combination of natural rubber and styrene-butadiene rubber in a ratio of 30 / 70-70 / 30, and the reinforcing agent is a combination of carbon black and white carbon black.

[0009] Preferably, the process oil is environmentally friendly aromatic oil TDAE, and the vulcanizing agent is oil-extended insoluble sulfur.

[0010] Preferably, the resorcinol is resorcinol-80 (BP-80), the accelerator is a sulfonamide accelerator NS, and the sulfonamide accelerator NS is a delayed-effect vulcanizing agent, and the adhesive is RA-65.

[0011] Another object of the present invention is to provide a method for preparing the rubber composition for duckbill valve cord rubber, comprising the following steps: S1, adding the rubber to an internal mixer to complete plastication, and after the plastication is completed, zinc oxide, stearic acid, operating oil, resorcinol and molybdenum-based polybutadiene rubber are added through sieving in sequence, and mixing is continued. After mixing for 3 minutes, the top plug is raised, and mixing is continued for 5 minutes to discharge the rubber to form a masterbatch; S2. The masterbatch is subjected to vacuum extrusion defoaming and then transferred to an open mill, and a vulcanizing agent, an accelerator and an adhesive are added. During the open milling process, a 3 / 4 cut is made three times on each side, and the mixture is thinly passed six times before being sheeted to obtain a rubber composition.

[0012] Preferably, in step S1, the temperature of the internal mixer is 80° C. and the rotation speed is 80 rpm.

[0013] Preferably, in step S2, the temperature of the mixing mill is 50±5°C.

[0014] Preferably, the equipment used in the steps S1-S2 is a rubber product production device, which includes an internal mixer, a screening mechanism is provided at the position of the internal mixer input port, an auger input end is flange-connected to the internal mixer output end, a defoaming mechanism is provided at the auger output end, an open mixer is provided below the defoaming mechanism, and a cutting mechanism is provided on the open mixer; The defoaming mechanism includes a fuselage connected to a flange at an output end of the auger, symmetrically distributed puncturing parts are arranged on left and right sides of the fuselage, the puncturing parts include a first electric telescopic rod penetrated through the fuselage, the output end of the first electric telescopic rod is rotatably connected to one end of a connecting rod, the other end of the connecting rod is rotatably connected to a protrusion, the connecting rod and the output end and the protrusion of the first electric telescopic rod are rotatably connected via a rotating pair, a vertical plate is fixed to the bottom of an inner wall of the fuselage, a needle plate is hinged to the top of the vertical plate, a slide rail is vertically fixed to the needle plate close to one side of the first electric telescopic rod, and the protrusion slides in the slide rail.

[0015] With the above structure, after the mother rubber enters the fuselage through the auger, two first electric telescopic rods are extended, and the connecting rod rotates between the two rotating pairs with the movement of the first electric telescopic rod. The rotating pair fixed with the protrusion drives the protrusion to slide in the slide rail and exerts force on the needle plate. The needle plate is subjected to force and rotates toward the second electric telescopic rod with the hinge at the top of the vertical plate as the center. Several fine needles on the needle plate pierce the mother rubber, so that multiple small holes are generated in the mother rubber, and small bubbles in the mother rubber will be pierced during the piercing process of some fine needles, thereby achieving preliminary defoaming.

[0016] A second electric telescopic rod and a vacuum pump are fixed to the top of the fuselage by bolts, a telescopic groove is provided at the bottom of the second electric telescopic rod, a short rod slides up and down in the telescopic groove, a pressing plate is fixed to the bottom of the short rod, a spring is fixed between the pressing plate and the bottom of the second electric telescopic rod, a high-temperature resistant silicone cover is fixed to the bottom of the pressing plate, and the output end of the vacuum pump is connected to the high-temperature resistant silicone cover.

[0017] With the above structure, after the initial defoaming, the first electric telescopic rod is retracted and the second electric telescopic rod is extended. The second electric telescopic rod drives the pressure plate to move downward through the spring and the short rod. The high-temperature resistant silicone cover moves downward with the pressure plate to contact the masterbatch and the lower inner wall of the fuselage. The restoring force of the spring drives the bottom of the high-temperature resistant silicone cover to be close to the lower inner wall of the fuselage. The vacuum pump is operated to evacuate the inside of the high-temperature resistant silicone cover. The high-temperature resistant silicone cover adapts to deformation as the vacuum environment is formed, so that the masterbatch is placed in the vacuum environment. The effect of the vacuum negative pressure is used to rupture and discharge the bubbles in the mixture, thereby realizing secondary defoaming. Since the masterbatch is pierced in advance, the piercing increases the contact area between the air and the masterbatch, thereby improving the defoaming efficiency, reducing the bubbles in the masterbatch during refining, improving the quality of the finished rubber mixture, optimizing its performance, and improving its durability.

[0018] A storage groove is provided at the lower rear of the inner wall of the fuselage, and a third electric telescopic rod is passed through the storage groove. The third electric telescopic rod is fixed to the fuselage, and a push plate is fixed to the front end of the third electric telescopic rod, and the push plate is adapted to the storage groove. A second motor is fixed to the front end of the left side of the fuselage, and a revolving door is fixed to the output end of the second motor.

[0019] By adopting the above structure, after the masterbatch is defoamed for the second time, the vacuum pump is turned off to cancel its vacuum state, the second electric telescopic rod is retracted, the second motor drives the revolving door to rotate upward, the third electric telescopic rod is extended, and the push plate is driven to move forward. During the forward movement of the push plate, the masterbatch is pushed between the front roller and the rear roller of the mixing mill, so that the masterbatch is discharged in the defoaming mechanism, and manual contact with the masterbatch is avoided, and the masterbatch is avoided from being contaminated during contact with people. While improving production efficiency and finished product quality, it keeps operators away from the production line and improves the production safety of workers.

[0020] The screening mechanism includes a bracket, a chassis is fixed on the top of the bracket, a third motor is fixed on the bottom of the chassis, a rotating shaft is fixed on the output end of the third motor, one end of five mounting frames is fixed on the top of the rotating shaft, a trapezoidal block is embedded on the other end of the mounting frame, a screen is integrally formed on the trapezoidal block, a fixing rod is fixed on the top of the chassis, an output cylinder is fixed on the top of the fixing rod, an input cylinder is fixed above the output cylinder through a welding rod, the distance between the input cylinder and the output cylinder is the same as the height of the screen, a top plate is fixed on the top of the welding rod, a first motor is fixed on the top center of the top plate, a scraper is fixed on the output end of the first motor, and the scraper is in contact with the screen.

[0021] With the above structure, the feed port of the internal mixer is rotated out, and the output cylinder is aligned with the feed port of the internal mixer. The third motor is driven to rotate the rotating shaft, and the five rotating shafts drive the screens of different meshes to rotate until the required screen is rotated between the input cylinder and the output cylinder. If none of the five screens have the required mesh, the screens and the mounting frame can be held and force applied in reverse up and down respectively. After the trapezoidal block on the screen is separated from the mounting frame, the screen of the required mesh is clamped to the mounting frame from top to bottom through the trapezoidal block to achieve interlocking. The trapezoid realizes the limitation of the horizontal plane range. After the screen of the required mesh is located between the input cylinder and the output cylinder, the additive is poured into the input cylinder, and the first motor drives the scraper to rotate on the surface of the screen to screen the qualified additive into the internal mixer through the output cylinder. The unqualified additive is taken out and weighed, and the qualified additive is supplemented with the weight to enter the internal mixer for mixing. By pre-treating the additive, the quality of the raw materials is optimized and the quality of the finished product is improved.

[0022] Preferably, the cutting knife mechanism includes a rotating rod rotatably connected to the mixing mill, a control turntable and a first gear are fixed on the rotating rod, and the rotating rod is rotatably connected to the mixing mill through a damping bearing, a mounting rod is rotatably connected to the mixing mill, one end of the mounting rod close to the first gear is keyed to the second gear, the first gear is meshed with the second gear, an mounting groove is horizontally opened at the center of the mounting rod, a double-headed motor is fixed at the center of the mounting groove, a lead screw is fixed to the output end of the double-headed motor, a slider is threadedly connected to the lead screw, and a spring knife is fixed to the rear end of the slider.

[0023] With the above structure, the handheld control turntable rotates upward or downward, and the rotating rod rotates with the control turntable (the damping bearing allows the angle to have a temporary stop function after rotation). The first gear rotates with the control turntable and transmits it to the second gear. The second gear drives the mounting rod to rotate. The spring knife rotates with the mounting rod to adjust the angle on the mixing mill. When the position of the cutting knife needs to be adjusted, the double-headed motor is operated to drive the lead screw to rotate. The slider and the mounting rod are fully fitted with a limit function of left and right linear motion. The slider and the lead screw generate threaded transmission, so that the slider can achieve left and right linear motion. The spring knife moves with the slider. The above operation replaces the manual handheld cutting knife to perform the cutting operation on the rubber mixture in the mixing mill, and the position of the cutting knife is more accurate after movement, thereby improving production efficiency.

[0024] Another object of the present invention is to provide application of the rubber composition in duckbill valve cord rubber.

[0025] Compared with the prior art, the rubber composition for duckbill valve cord rubber and its preparation method and application have the following advantages: 1. The insoluble sulfur in the raw material of the rubber composition of the present invention is evenly dispersed in the rubber material and can maintain the viscosity of the semi-finished product. Resorcinol-80 (BP-80) as an active additive can react with the double bonds in the rubber molecules to form a cross-linked structure and improve the aging resistance of the rubber. It can also react with metal ions to form a stable complex. Molybdenum-based polybutadiene rubber (CVBR) has higher raw rubber strength, higher wear resistance, higher tensile strength, and higher crack growth resistance, which can improve the stiffness of the rubber material and the deformation resistance of the product.

[0026] 2. In the preparation process of the rubber composition, the electric drive of the auger, the third electric telescopic rod and the push rod is used to realize the loading and unloading of materials, avoid manual operation, improve production efficiency, reduce the dust and other pollution caused by the exposure time of the material in the air, improve the quality of the finished product, and reduce the contact between the staff and the high-temperature materials to avoid burns, thereby improving the safety of the production process. In addition, a defoaming step is added during the input of the masterbatch from the internal mixer to the open mixer to reduce the bubbles in the masterbatch and increase the masterbatch density, thereby improving the hardness and strength of the finished rubber composition, improving the performance of the duckbill valve cord rubber used, and increasing the service life.

[0027] 3. A number of fine needles on the needle plate driven by the first electric telescopic rod pierce the masterbatch to produce multiple small holes in the masterbatch, and some fine needles will pierce small bubbles in the masterbatch during the piercing process to achieve preliminary defoaming. The high-temperature resistant silicone cover is evacuated by a vacuum pump. The high-temperature resistant silicone cover adapts to deformation as the vacuum environment is formed, so that the masterbatch is placed in a vacuum environment. The bubbles in the mixture are broken and discharged by the effect of vacuum negative pressure to achieve secondary defoaming. Since the masterbatch is pierced in advance, the piercing increases the contact area between air and masterbatch, improves the defoaming efficiency, reduces the bubbles in the masterbatch during refining, improves the quality of the finished rubber mixture, optimizes its performance, and improves durability.

[0028] 4. The third electric telescopic rod is extended to drive the push plate to move forward. During the forward movement of the push plate, the masterbatch is pushed between the front roller and the rear roller of the mixing mill to realize the unloading of the masterbatch in the defoaming mechanism, avoiding manual contact with the masterbatch and the masterbatch being contaminated during contact with people. While improving production efficiency and finished product quality, it keeps operators away from the production line and improves workers' production safety.

[0029] 5. The third motor drives the rotating shaft to rotate, and the five rotating shafts drive the screens of different meshes to rotate until the required screen rotates between the input cylinder and the output cylinder. If none of the five screens have the required mesh, the screen can be replaced faster to improve production efficiency. The screening mechanism can hold the screen and the mounting frame and apply force up and down in reverse. After the trapezoidal block on the screen is separated from the mounting frame, the screen of the required mesh is clamped from top to bottom to the mounting frame through the trapezoidal block to achieve interlocking. The operation is simple and suitable for screens of more specifications. It can be replaced during the screening process of the previous additive. The overlapping operation time reduces the production time and improves production efficiency. The trapezoid realizes the limitation of the horizontal plane range. After the screen of the required mesh is located between the input cylinder and the output cylinder, the additive is poured into the input cylinder. The first motor drives the scraper to rotate on the surface of the screen, and the qualified additive is screened into the internal mixer through the output cylinder. The unqualified additive is taken out and weighed, and the qualified additive is supplemented with the weight to enter the internal mixer for mixing. By pre-treating the additive, the quality of the raw materials is optimized and the quality of the finished product is improved.

[0030] 6. The hand-held control dial rotates upward or downward, and the rotating rod rotates with the control dial (the damping bearing allows the angle to be temporarily stopped after rotation). The first gear rotates with the control dial and transmits to the second gear. The second gear drives the mounting rod to rotate. Mechanical transmission prevents manual access to the cutter body, thereby improving safety. It is unnecessary for manual access to the high-temperature colloid during the refining process, thereby improving safety. The spring knife rotates with the mounting rod to adjust the angle on the refining mill. When the position of the cutter needs to be adjusted, the double-headed motor is driven to rotate the lead screw. The slider and the mounting rod are fully fitted with a limit function for left and right linear motion. The slider and the lead screw generate threaded transmission, so that the slider can achieve left and right linear motion. The spring knife moves with the slider. The above operation replaces the manual hand-held cutter to cut the rubber mixture in the refining, and the position of the cutter is more accurate after movement, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a preparation process flow chart of the present invention.

[0032] Figure 2 It is a schematic diagram of the overall structure of the rubber product production device in the present invention.

[0033] Figure 3 It is a schematic diagram of the overall structure of the defoaming mechanism in the present invention.

[0034] Figure 4 It is a structural schematic diagram of the piercing portion in the present invention.

[0035] Figure 5 It is a structural schematic diagram of the transfer rod part of the present invention.

[0036] Figure 6 It is a structural schematic diagram of the needle plate part in the present invention.

[0037] Figure 7 It is a schematic longitudinal section diagram of the structure of the telescopic slot part in the present invention.

[0038] Figure 8 It is a schematic diagram of the longitudinal section of the structure of the spring part in the present invention.

[0039] Fig. 9 It is a schematic structural diagram of the storage tank part in the present invention.

[0040] Fig.10 It is a schematic diagram of the overall structure of the screening mechanism in the present invention.

[0041] Fig.11 It is a schematic longitudinal section diagram of the structure of the input cylinder part in the present invention.

[0042] Fig.12 It is a schematic diagram of the overall structure of the mixing mill part in the present invention.

[0043] Fig.13 yes Fig.12 A magnified view of the structure at center.

[0044] Fig.14 It is a schematic diagram of the overall structure of the cutting knife mechanism in the present invention.

[0045] Fig.15 This is a comparison table of the data after the test in the experimental example.

[0046] Fig.16 The effect of different proportions of resorcinol-80 on the performance of the rubber compound.

[0047] Fig.17 The influence of different proportions of CVBR on the performance of the rubber compound.

[0048] In the figure, 1, internal mixer; 2, screening mechanism; 201, bracket; 202, chassis; 203, screen; 204, fixing rod; 205, output cylinder; 206, welding rod; 207, input cylinder; 208, top plate; 209, first motor; 210, mounting frame; 211, trapezoidal block; 212, rotating shaft; 213, scraper; 214, third motor; 3, auger; 4, defoaming mechanism; 401, fuselage; 402, first electric telescopic rod; 403, rotating pair; 404, connecting rod; 405, slide rail; 406, needle plate; 407, vertical plate; 408 , second electric telescopic rod; 409, telescopic slot; 410, short rod; 411, spring; 412, pressure plate; 413, high temperature resistant silicone cover; 414, vacuum pump; 415, third electric telescopic rod; 416, push plate; 417, storage slot; 418, bump; 419, revolving door; 420, second motor; 5, open mill; 6, cutting knife mechanism; 601, rotating rod; 602, control turntable; 603, first gear; 604, second gear; 605, mounting rod; 606, double-headed motor; 607, lead screw; 608, slider; 609, spring knife. DETAILED DESCRIPTION

[0049] 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.

[0050] Example 1 The rubber composition used for duckbill valve cord rubber is composed of the following raw materials in parts by mass: 100 parts of rubber, 70 parts of reinforcing agent (including 60 parts of carbon black and 10 parts of white carbon black), 1 part of zinc oxide, 1 part of stearic acid, 3 parts of vulcanizing agent, 1.2 parts of accelerator, 6 parts of operating oil, 1.5 parts of resorcinol, 2.5 parts of adhesive, and 10 parts of molybdenum-based polybutadiene rubber (CVBR).

[0051] The rubber is a combination of natural rubber and styrene-butadiene rubber in a ratio of 50 / 50, the reinforcing agent is a combination of carbon black and white carbon black, the operating oil is environmentally friendly aromatic oil TDAE, and the vulcanizing agent is oil-extended insoluble sulfur.

[0052] The resorcinol is resorcinol-80 (BP-80), the accelerator is sulfonamide accelerator NS, and the sulfonamide accelerator NS is a post-effect vulcanizing agent, and the adhesive is RA-65.

[0053] The method for preparing the rubber composition for duckbill valve cord rubber comprises the following steps: S1, adding rubber to an internal mixer to complete plastication, the temperature of the internal mixer is 80°C, the speed is 80rmp, after the plastication is completed, zinc oxide, stearic acid, operating oil, resorcinol and molybdenum polybutadiene rubber are added in sequence through sieving, and mixing is continued. After mixing for 3 minutes, the upper plug is raised, and mixing is continued for 5 minutes to discharge the rubber to form a masterbatch; S2. The masterbatch is subjected to vacuum extrusion and defoaming and then transferred to an open mixing mill. The temperature of the open mixing mill is 51°C, and a vulcanizer, an accelerator and an adhesive are added. During the mixing process, a 3 / 4 cut is made three times on each side, and the mixture is thinly passed six times before being sheeted to obtain a rubber composition.

[0054] The equipment used in the method for preparing the rubber composition for duckbill valve cord rubber in this embodiment 1 is all existing conventional equipment.

[0055] Example 2 like Figure 1 As shown in the figure, the rubber composition for duckbill valve cord rubber is composed of the following raw materials in parts by mass: 100 parts of rubber, 70 parts of reinforcing agent (including 60 parts of carbon black and 10 parts of white carbon black), 1 part of zinc oxide, 1 part of stearic acid, 3 parts of vulcanizing agent, 1.2 parts of accelerator, 6 parts of operating oil, 1.5 parts of resorcinol, 2.5 parts of adhesive, and 10 parts of molybdenum-based polybutadiene rubber (CVBR).

[0056] The rubber is a combination of natural rubber and styrene-butadiene rubber in a ratio of 50 / 50, the reinforcing agent is a combination of carbon black and white carbon black, the operating oil is environmentally friendly aromatic oil TDAE, and the vulcanizing agent is oil-extended insoluble sulfur.

[0057] The resorcinol is resorcinol-80 (BP-80), the accelerator is sulfonamide accelerator NS, and the sulfonamide accelerator NS is a post-effect vulcanizing agent, and the adhesive is RA-65.

[0058] The method for preparing the rubber composition for duckbill valve cord rubber comprises the following steps: S1, adding rubber to an internal mixer to complete plastication, the temperature of the internal mixer is 80°C, the speed is 80rmp, after the plastication is completed, zinc oxide, stearic acid, operating oil, resorcinol and molybdenum polybutadiene rubber are added in sequence through sieving, and mixing is continued. After mixing for 3 minutes, the upper plug is raised, and mixing is continued for 5 minutes to discharge the rubber to form a masterbatch; S2. The masterbatch is subjected to vacuum extrusion and defoaming and then transferred to an open mixing mill. The temperature of the open mixing mill is 51°C, and a vulcanizer, an accelerator and an adhesive are added. During the mixing process, a 3 / 4 cut is made three times on each side, and the mixture is thinly passed six times before being sheeted to obtain a rubber composition.

[0059] like Figure 2-Figure 14 As shown, the equipment used in steps S1-S2 is a rubber product production device, which includes an internal mixer 1. A screening mechanism 2 is provided at the input port of the internal mixer 1. The output end flange of the internal mixer 1 is connected to the input end of an auger 3. The output end of the auger 3 is provided with a defoaming mechanism 4. An open mixer 5 is provided below the defoaming mechanism 4. A cutting mechanism 6 is provided on the open mixer 5.

[0060] In this embodiment, the internal mixer 1, the auger 3 and the mixing mill 5 are all of the prior art.

[0061] The defoaming mechanism 4 includes a fuselage 401 connected to the output end flange of the auger 3, and symmetrically distributed puncturing parts are arranged on the left and right sides of the fuselage 401. The puncturing part includes a first electric telescopic rod 402 penetrated by the fuselage 401, and the output end of the first electric telescopic rod 402 is rotatably connected to one end of a connecting rod 404, and the other end of the connecting rod 404 is rotatably connected to a protrusion 418. The connecting rod 404 is rotatably connected to the output end and the protrusion 418 of the first electric telescopic rod 402 through a rotating pair 403. A vertical plate 407 is fixed to the bottom of the inner wall of the fuselage 401, and a needle plate 406 is hinged on the top of the vertical plate 407. A slide rail 405 is vertically fixed to the needle plate 406 close to the side of the first electric telescopic rod 402, and the protrusion 418 slides in the slide rail 405.

[0062] In this embodiment, the first electric telescopic rod 402 is the prior art. After the mother rubber enters the fuselage 401 completely through the auger 3, the two first electric telescopic rods 402 are extended, and the connecting rod 404 rotates between the two rotating pairs 403 with the movement of the first electric telescopic rod 402. The rotating pair 403 fixed with the protrusion 418 drives the protrusion 418 to slide in the slide rail 405 and applies force to the needle plate 406. The needle plate 406 is subjected to the force and rotates toward the second electric telescopic rod 408 with the hinge at the top of the vertical plate 407 as the center. Several fine needles on the needle plate 406 pierce the mother rubber, so that a plurality of small holes are generated in the mother rubber, and small bubbles in the mother rubber will be pierced during the piercing process of some fine needles, thereby achieving preliminary defoaming.

[0063] A second electric telescopic rod 408 and a vacuum pump 414 are fixed to the top of the fuselage 401 by bolts. A telescopic groove 409 is provided at the bottom of the second electric telescopic rod 408. A short rod 410 slides up and down in the telescopic groove 409. A pressing plate 412 is fixed to the bottom of the short rod 410. A spring 411 is fixed between the pressing plate 412 and the bottom of the second electric telescopic rod 408. A high-temperature resistant silicone cover 413 is fixed to the bottom of the pressing plate 412, and the output end of the vacuum pump 414 is connected to the high-temperature resistant silicone cover 413.

[0064] In this embodiment, the second electric telescopic rod 408 and the vacuum pump 414 are both prior art. The vacuum pump 414 is connected to the high temperature resistant silicone cover 413 through a pressure-resistant hose. After initial defoaming, the first electric telescopic rod 402 is retracted, and the second electric telescopic rod 408 is extended. The second electric telescopic rod 408 drives the pressing plate 412 to move downward through the spring 411 and the short rod 410. The high temperature resistant silicone cover 413 moves downward with the pressing plate 412 to contact the masterbatch and the lower inner wall of the fuselage 401. The restoring force of the spring 411 drives the bottom of the high temperature resistant silicone cover 413 to move downward. Closely attached to the lower inner wall of the fuselage 401, the vacuum pump 414 is operated to evacuate the inside of the high-temperature resistant silicone cover 413. The high-temperature resistant silicone cover 413 adapts to deformation as the vacuum environment is formed, so that the masterbatch is placed in the vacuum environment, and the bubbles in the mixture are broken and discharged by the effect of vacuum negative pressure, thereby realizing secondary defoaming. Since the masterbatch is pierced in advance, the piercing increases the contact area between the air and the masterbatch, thereby improving the defoaming efficiency, reducing the bubbles in the masterbatch during the mixing, improving the quality of the finished rubber mixture, optimizing its performance, and improving its durability.

[0065] A storage groove 417 is provided at the lower rear of the inner wall of the fuselage 401, and a third electric telescopic rod 415 is passed through the storage groove 417. The third electric telescopic rod 415 is fixed to the fuselage 401, and a push plate 416 is fixed to the front end of the third electric telescopic rod 415. The push plate 416 is adapted to the storage groove 417. A second motor 420 is fixed to the front left side of the fuselage 401, and a revolving door 419 is fixed to the output end of the second motor 420.

[0066] In this embodiment, the second motor 420 and the third electric telescopic rod 415 are both existing technologies. After the masterbatch is defoamed for the second time, the vacuum pump 414 is turned off to cancel its vacuum state, and the second electric telescopic rod 408 is retracted. The second motor 420 drives the revolving door 419 to rotate upward, and the third electric telescopic rod 415 is extended, driving the push plate 416 to move forward. During the forward movement of the push plate 416, the masterbatch is pushed between the front roller and the rear roller of the mixing mill 5, so that the masterbatch is discharged in the defoaming mechanism 4, avoiding manual contact with the masterbatch, and avoiding the masterbatch from being contaminated during contact with people. While improving production efficiency and finished product quality, it keeps operators away from the production line and improves the production safety of workers.

[0067] The screening mechanism 2 includes a bracket 201, a chassis 202 is fixed on the top of the bracket 201, a third motor 214 is fixed on the bottom of the chassis 202, a rotating shaft 212 is fixed on the output end of the third motor 214, one end of five mounting frames 210 are fixed on the top of the rotating shaft 212, a trapezoidal block 211 is embedded on the other end of the mounting frame 210, a screen 203 is integrally formed on the trapezoidal block 211, a fixing rod 204 is fixed on the top of the chassis 202, an output cylinder 205 is fixed on the top of the fixing rod 204, an input cylinder 207 is fixed above the output cylinder 205 through a welding rod 206, the distance between the input cylinder 207 and the output cylinder 205 is the same as the height of the screen 203, a top plate 208 is fixed on the top of the welding rod 206, a first motor 209 is fixed on the top center of the top plate 208, a scraper 213 is fixed on the output end of the first motor 209, and the scraper 213 is in contact with the screen 203.

[0068] In this embodiment, the third motor 214 and the first motor 209 are both prior art. The feed port of the internal mixer 1 is rotated out, and the output cylinder 205 is aligned with the feed port of the internal mixer 1. The third motor 214 is operated to drive the rotating shaft 212 to rotate. The rotating shaft 212 drives the five screens 203 of different meshes to rotate until the required screen 203 rotates between the input cylinder 207 and the output cylinder 205. If none of the five screens 203 has the required mesh, the screen 203 and the mounting frame 210 can be held by hand and applied in reverse up and down, and the trapezoidal block 211 on the screen 203 is separated from the mounting frame 210, and the required mesh is The screen 203 is engaged with the mounting frame 210 from top to bottom through the trapezoidal block 211, and the trapezoid is used to limit the horizontal plane range. After the screen 203 with the required mesh size is located between the input cylinder 207 and the output cylinder 205, the additive is poured into the input cylinder 207, and the first motor 209 drives the scraper 213 to rotate on the surface of the screen 203, and the qualified additive is screened into the internal mixer 1 through the output cylinder 205. The unqualified additive is taken out and weighed, and the qualified additive is supplemented with the weight and enters the internal mixer 1 for mixing. By pre-treating the additive, the quality of the raw materials is optimized and the quality of the finished product is improved.

[0069] The cutting knife mechanism 6 includes a rotating rod 601 rotatably connected to the mixing mill 5, on which a control turntable 602 and a first gear 603 are fixed, and the rotating rod 601 is rotatably connected to the mixing mill 5 through a damping bearing, and a mounting rod 605 is rotatably connected to the mixing mill 5, and one end of the mounting rod 605 close to the first gear 603 is keyed to the second gear 604, and the first gear 603 is meshed with the second gear 604, and a mounting groove is horizontally opened at the center of the mounting rod 605, and a double-headed motor 606 is fixed at the center of the mounting groove, and a lead screw 607 is fixed to the output end of the double-headed motor 606, a slider 608 is threadedly connected to the lead screw 607, and a spring knife 609 is fixed to the rear end of the slider 608.

[0070] In this embodiment, the double-headed motor 606, the damping bearing and the spring knife 609 are all existing technologies. The hand-held control dial 602 rotates upward or downward, and the rotating rod 601 rotates with the control dial 602 (the damping bearing allows the angle to have a temporary stop function after rotation). The first gear 603 rotates with the control dial 602 and is transmitted to the second gear 604. The second gear 604 drives the mounting rod 605 to rotate. The spring knife 609 rotates with the mounting rod 605 to adjust the angle on the mixing mill 5. When the cutting knife position needs to be adjusted, the double-headed motor 606 is operated to drive the lead screw 607 to rotate. The slider 608 and the mounting rod 605 are fully fitted with the limit function of left and right linear motion. The slider 608 and the lead screw 607 generate threaded transmission, so that the slider 608 can realize left and right linear motion, and the spring knife 609 moves with the slider 608. The above operation replaces the manual hand-held cutting knife to cut the rubber mixture in the mixing mill, and the cutting knife position is more accurate after movement, thereby improving production efficiency.

[0071] Example 3 The rubber composition used for duckbill valve cord rubber is composed of the following raw materials in parts by mass: 100 parts of rubber, 30 parts of reinforcing agent, 5 parts of zinc oxide, 0.5 parts of stearic acid, 3.5 parts of vulcanizing agent, 0.5 parts of accelerator, 8 parts of operating oil, 0.5 parts of resorcinol, 4 parts of adhesive, and 5 parts of molybdenum-based polybutadiene rubber (CVBR).

[0072] The rubber is a combination of natural rubber and styrene-butadiene rubber, with a ratio of 30 / 70, and the reinforcing agent is a combination of carbon black and white carbon black. The operating oil is environmentally friendly aromatic oil TDAE, and the vulcanizing agent is oil-extended insoluble sulfur.

[0073] The resorcinol is resorcinol-80 (BP-80), the accelerator is sulfonamide accelerator NS, and the sulfonamide accelerator NS is a post-effect vulcanizing agent, and the adhesive is RA-65.

[0074] The method for preparing the rubber composition for duckbill valve cord rubber comprises the following steps: S1, adding rubber to an internal mixer to complete plastication, the temperature of the internal mixer is 80°C, the speed is 80rmp, after the plastication is completed, zinc oxide, stearic acid, operating oil, resorcinol and molybdenum polybutadiene rubber are added in sequence through sieving, and mixing is continued. After mixing for 3 minutes, the upper plug is raised, and mixing is continued for 5 minutes to discharge the rubber to form a masterbatch; S2. The masterbatch is subjected to vacuum extrusion and defoaming and then transferred to an open mixing mill. The temperature of the open mixing mill is 50°C, and a vulcanizer, an accelerator and an adhesive are added. During the mixing process, a 3 / 4 cut is made three times on each side, and the mixture is thinly passed six times before being sheeted to obtain a rubber composition.

[0075] In the preparation process of the rubber composition in this embodiment, the processing equipment used is the same as that in Example 2, and the difference lies in the formula ratio and processing conditions.

[0076] Example 4 The rubber composition used for duckbill valve cord rubber is composed of the following raw materials in parts by mass: 100 parts of rubber, 80 parts of reinforcing agent, 1 part of zinc oxide, 3 parts of stearic acid, 1 part of vulcanizing agent, 2 parts of accelerator, 2 parts of operating oil, 2.5 parts of resorcinol, 1 part of adhesive, and 15 parts of molybdenum-based polybutadiene rubber (CVBR).

[0077] The rubber is a combination of natural rubber and styrene-butadiene rubber, with a ratio of 70 / 30, the reinforcing agent is a combination of carbon black and white carbon black, the operating oil is environmentally friendly aromatic oil TDAE, and the vulcanizing agent is oil-extended insoluble sulfur.

[0078] The resorcinol is resorcinol-80 (BP-80), the accelerator is sulfonamide accelerator NS, and the sulfonamide accelerator NS is a post-effect vulcanizing agent, and the adhesive is RA-65.

[0079] The method for preparing the rubber composition for duckbill valve cord rubber comprises the following steps: S1, adding rubber to an internal mixer to complete plastication, the temperature of the internal mixer is 80°C, the speed is 80rmp, after the plastication is completed, zinc oxide, stearic acid, operating oil, resorcinol and molybdenum polybutadiene rubber are added in sequence through sieving, and mixing is continued. After mixing for 3 minutes, the upper plug is raised, and mixing is continued for 5 minutes to discharge the rubber to form a masterbatch; S2. The masterbatch is subjected to vacuum extrusion and defoaming and then transferred to an open mixing mill. The temperature of the open mixing mill is 55° C., and vulcanizer, accelerator and adhesive are added. During the mixing process, 3 / 4 cuts are made on each side three times, and the mixture is thinly passed six times before being sheeted to obtain a rubber composition.

[0080] The method for preparing the rubber composition in this Example 4 uses the same processing equipment as that in Example 2, except for the formula ratio and processing conditions.

[0081] Experimental example The rubber mixtures prepared according to Examples 1 to 4 were vulcanized at 150°C for 30 minutes and then subjected to relevant test experiments. Fig.15 : Hardness is measured according to GB / T531.1-2008 and is expressed as HA; 300% elongation stress is measured according to GBT528-2009 and expressed in MPa; The tensile strength is measured according to GBT528-2009 and expressed in MPa; The elongation at break is measured according to GBT528-2009 and expressed in %; Permanent deformation is measured according to GBT528-2009 and expressed in %; The tear strength is measured according to GB / T529-2008 and expressed in kN / m.

[0082] The preparation devices for the rubber mixture in Example 1 and Example 2 are different, but the hardness, 300% tensile stress, tensile strength, elongation at break, permanent deformation, and tear strength of the rubber mixture in Example 2 are better than those in Example 1. Therefore, the use of the rubber product production device in the present invention can improve the hardness, 300% tensile stress, tensile strength, elongation at break, permanent deformation, and tear strength of the rubber mixture.

[0083] The preparation process conditions and formulation ratios of the rubber mixture in Example 3, Example 4 and Example 2 are different, but the hardness, 300% tensile stress, tensile strength, elongation at break, permanent deformation and tear strength of the rubber mixture in Example 2 are better than those in Example 3 and Example 4. Therefore, different process conditions will also affect the hardness, 300% tensile stress, tensile strength, elongation at break, permanent deformation, tear strength and other properties of the rubber mixture.

[0084] Example 5 The technical feature that distinguishes Example 5 of the present invention from Example 2 is that the weight portion of resorcinol-80 is 0.5 parts.

[0085] Example 6 The technical feature that distinguishes Example 6 of the present invention from Example 2 is that the weight portion of resorcinol-80 is 2.5 parts.

[0086] Comparative Example 1 The technical feature of the comparison example 1 and the embodiment 2 is that the weight portion of resorcinol-80 is 0.

[0087] Example 7 The technical feature that distinguishes Example 7 of the present invention from Example 2 is that the weight portion of CVBR is 5 parts.

[0088] Example 8 The technical feature that distinguishes Example 8 of the present invention from Example 2 is that the weight portion of CVBR is 15 parts.

[0089] Comparative Example 2 The technical feature that Comparative Example 2 differs from Example 2 is that the weight portion of CVBR is 0.

[0090] The results of the performance tests on the rubber materials prepared in the above-mentioned Example 2, Example 5-Example 8 and Comparative Examples 1-2 are shown in Figure 16-Figure 17 shown.

[0091] pass Fig.16It can be seen from the performance test data in Example 2, Examples 5-6 and Comparative Example 1 that the addition amount of resorcinol-80 will have a significant impact on the performance of the rubber. When resorcinol-80 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 can be significantly improved; when no resorcinol-80 additive is added in the comparative example, the hardness, tensile stress, tensile strength, tensile elongation, tear strength, resilience and other properties of the rubber are significantly reduced. This is because resorcinol-80 (BP-80), as an active auxiliary agent, can react with the double bonds in the rubber molecules to form a cross-linked structure and improve the aging resistance of the rubber. It can also react with metal ions to form a stable complex; if the content of resorcinol-80 is too large, excessive resorcinol may change the cross-linked structure of the rubber molecular chain, causing the material to become brittle or lose elasticity. If the content of resorcinol-80 is too small, the bonding effect is poor, affecting the overall stability of the rubber product.

[0092] pass Fig.17 It can be seen from the various performance test data in Example 2, Example 7-8 and Comparative Example 2 that the addition amount of CVBR will have a significant impact on the performance of the rubber compound. When CVBR 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 compound can be significantly improved; when the CVBR additive is not added in the comparative example, the hardness, tensile stress, tensile strength, tensile elongation, tear strength, resilience and other properties of the rubber compound are significantly reduced. This is because CVBR has higher raw rubber strength, high wear resistance, higher tensile strength, and higher crack growth resistance, which can improve the stiffness of the rubber compound and the deformation resistance of the product; if the content of CVBR is too large, it will lead to the destruction of the filler network structure of the rubber, resulting in an increase in the shear storage modulus of the vulcanized rubber and an increase in the loss factor. This will affect the wear resistance, low heat generation and high-speed maneuverability of the rubber product, making it easy to heat up and wear faster during use, and even affecting the service life, causing the material to become brittle or lose elasticity. If the content of CVBR is too small, it will lead to the inability to give full play to its excellent properties, such as excellent aging resistance, low heat generation and high anti-slip properties.

[0093] It can be seen from the above examples and comparative examples that the present invention can effectively improve the heat resistance, viscosity, tensile strength and hardness properties of the rubber composition by adding resorcinol and CVBR to the components.

[0094] 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 rubber composition for duckbill valve cord rubber, characterized in that: The invention is composed of the following raw materials in parts by mass: 100 parts of rubber, 30-80 parts of reinforcing agent, 1-5 parts of zinc oxide, 0.5-3 parts of stearic acid, 1-3.5 parts of vulcanizing agent, 0.5-2 parts of accelerator, 2-8 parts of operating oil, 0.5-2.5 parts of resorcinol, 1-4 parts of adhesive and 5-15 parts of molybdenum-based polybutadiene rubber (CVBR).

2. The rubber composition for duckbill valve cord rubber according to claim 1, characterized in that: The composition is composed of the following raw materials in parts by mass: 100 parts of rubber, 70 parts of reinforcing agent, 1 part of zinc oxide, 1 part of stearic acid, 3 parts of vulcanizing agent, 1.2 parts of accelerator, 6 parts of process oil, 1.5 parts of resorcinol, 2.5 parts of adhesive, and 10 parts of molybdenum-based polybutadiene rubber (CVBR).

3. The rubber composition for duckbill valve cord rubber according to claim 1, characterized in that: The rubber is a combination of natural rubber and styrene-butadiene rubber in a ratio of 30 / 70-70 / 30, and the reinforcing agent is a combination of carbon black and white carbon black.

4. The rubber composition for duckbill valve cord rubber according to claim 1, characterized in that: The operating oil is environmentally friendly aromatic oil TDAE, and the vulcanizing agent is oil-extended insoluble sulfur.

5. The rubber composition for duckbill valve cord rubber according to claim 1, characterized in that: The resorcinol is resorcinol-80 (BP-80), the accelerator is sulfonamide accelerator NS, and the sulfonamide accelerator NS is a post-effect vulcanizing agent, and the adhesive is RA-65.

6. A method for preparing a rubber composition for duckbill valve cord rubber according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, adding the rubber to an internal mixer to complete plastication, and after the plastication is completed, zinc oxide, stearic acid, operating oil, resorcinol and molybdenum-based polybutadiene rubber are added through sieving in sequence, and mixing is continued. After mixing for 3 minutes, the top plug is raised, and mixing is continued for 5 minutes to discharge the rubber to form a masterbatch; S2. The masterbatch is subjected to vacuum extrusion defoaming and then transferred to an open mill, and a vulcanizing agent, an accelerator and an adhesive are added. During the open milling process, a 3 / 4 cut is made three times on each side, and the mixture is thinly passed six times before being sheeted to obtain a rubber composition.

7. The method for preparing the rubber composition for duckbill valve cord rubber according to claim 6, characterized in that: In step S1, the temperature of the internal mixer is 80° C. and the rotation speed is 80 rpm.

8. The method for preparing the rubber composition for duckbill valve cord rubber according to claim 6, characterized in that: In step S2, the temperature of the mixing mill is 50±5°C.

9. The method for preparing the rubber composition for duckbill valve cord rubber according to claim 6, characterized in that: The equipment used in the steps S1-S2 is a rubber product production device, which comprises an internal mixer (1), a screening mechanism (2) is provided at the input port of the internal mixer (1), an output end of the internal mixer (1) is flange-connected to an input end of an auger (3), a defoaming mechanism (4) is provided at the output end of the auger (3), an open mixer (5) is provided below the defoaming mechanism (4), and a cutting mechanism (6) is provided on the open mixer (5); The defoaming mechanism (4) comprises a body (401) connected to a flange of an output end of an auger (3), symmetrically distributed puncturing parts are arranged on both left and right sides of the body (401), the puncturing parts comprise a first electric telescopic rod (402) penetrating the body (401), the output end of the first electric telescopic rod (402) is rotatably connected to one end of a connecting rod (404), the other end of the connecting rod (404) is rotatably connected to a protrusion (418), the connecting rod (404) and the output end and the protrusion (418) of the first electric telescopic rod (402) are rotatably connected via a rotating pair (403), a vertical plate (407) is fixed to the bottom of the inner wall of the body (401), a needle plate (406) is hinged to the top of the vertical plate (407), a slide rail (405) is vertically fixed to the side of the needle plate (406) close to the first electric telescopic rod (402), and the protrusion (418) slides in the slide rail (405); A second electric telescopic rod (408) and a vacuum pump (414) are fixed to the top of the body (401) by bolts; a telescopic groove (409) is provided at the bottom of the second electric telescopic rod (408); a short rod (410) slides up and down in the telescopic groove (409); a pressing plate (412) is fixed to the bottom of the short rod (410); a spring (411) is fixed between the pressing plate (412) and the bottom of the second electric telescopic rod (408); a high-temperature resistant silicone cover (413) is fixed to the bottom of the pressing plate (412); and an output end of the vacuum pump (414) is connected to the high-temperature resistant silicone cover (413); A storage groove (417) is provided at the lower rear of the inner wall of the body (401), a third electric telescopic rod (415) is inserted into the storage groove (417), the third electric telescopic rod (415) is fixed to the body (401), a push plate (416) is fixed to the front end of the third electric telescopic rod (415), the push plate (416) is matched with the storage groove (417), a second motor (420) is fixed to the front end of the left side of the body (401), and a rotating door (419) is fixed to the output end of the second motor (420); The screening mechanism (2) comprises a bracket (201), a chassis (202) is fixed on the top of the bracket (201), a third motor (214) is fixed on the bottom of the chassis (202), a rotating shaft (212) is fixed on the output end of the third motor (214), one end of five mounting frames (210) are fixed on the top of the rotating shaft (212), a trapezoidal block (211) is embedded on the other end of the mounting frame (210), a screen (203) is integrally formed on the trapezoidal block (211), and a fixing rod (204) is fixed on the top of the chassis (202). An output cylinder (205) is fixed to the top of the fixed rod (204), an input cylinder (207) is fixed above the output cylinder (205) via a welding rod (206), the distance between the input cylinder (207) and the output cylinder (205) is the same as the height of the screen (203), a top plate (208) is fixed to the top of the welding rod (206), a first motor (209) is fixed to the top center of the top plate (208), a scraper (213) is fixed to the output end of the first motor (209), and the scraper (213) is in contact with the screen (203); The cutting knife mechanism (6) comprises a rotating rod (601) rotatably connected to the mixing mill (5), a control rotating disk (602) and a first gear (603) being fixed on the rotating rod (601), and the rotating rod (601) is rotatably connected to the mixing mill (5) via a damping bearing, a mounting rod (605) is rotatably connected to the mixing mill (5), one end of the mounting rod (605) close to the first gear (603) is key-connected to the second gear (604), the first gear (603) and the second gear (604) are meshed, a mounting groove is transversely opened at the center of the mounting rod (605), a double-headed motor (606) is fixed at the center of the mounting groove, a lead screw (607) is fixed at the output end of the double-headed motor (606), a slider (608) is threadedly connected to the slider (607), and a spring knife (609) is fixed at the rear end of the slider (608).

10. Use of the rubber composition according to any one of claims 1 to 5 in duckbill valve cord rubber.

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