Low-smoke and low-toxicity rubber surface whole-core flame-retardant conveying belt for coal mine and preparation method thereof
By coating the woven core with a core paste layer and a flame-retardant rubber covering layer, and combining it with smoke-suppressing components such as zinc stannate and ferrocene, the problem of smoke and toxicity in fires of traditional PVC flame-retardant solid woven conveyor belts used in coal mines has been solved, achieving a low-smoke, low-toxicity flame-retardant effect, and improving the survival rate of coal miners and mechanical performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-20
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional PVC flame-retardant solid woven conveyor belts used in coal mines produce large amounts of smoke and toxic hydrogen halide gases in fires, leading to oxygen deficiency and obstructed vision for coal miners, increasing the risk of being trapped.
It uses a woven core as a skeleton, coated with a core paste layer and a flame-retardant rubber covering layer, and uses smoke-suppressing components such as zinc stannate, ferrocene, and ammonium molybdate to reduce smoke density and toxicity through a condensed phase flame-retardant mechanism.
It has low smoke density and low toxicity in fires, which improves the survival rate of coal miners, and has excellent physical and mechanical properties.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of flame-retardant conveyor belt technology, specifically relating to a low-smoke, low-toxicity rubber-faced solid-core flame-retardant conveyor belt for coal mines and its preparation method. Background Technology
[0002] Traditionally, PVC flame-retardant solid-core conveyor belts, used in underground coal mines, offer flame-retardant and antistatic properties. These belts typically consist of three parts: 1. A cover rubber primarily composed of PVC suspension resin, plasticizers, and flame retardants such as 52# chlorinated paraffin and antimony trioxide, as well as antistatic agents; 2. A core paste primarily composed of PVC paste resin, plasticizers, and flame retardants such as 52# chlorinated paraffin and antimony trioxide; 3. A solid core composed of industrial polyester filaments and cotton yarn. While this conveyor belt structure meets the physical properties and flame-retardant safety requirements of standards, it contains large amounts of PVC and halogenated flame retardants, as well as antimony trioxide, which produces significant smoke. Once ignited, it generates large amounts of smoke and toxic hydrogen halide gases. Inhaling high concentrations of these toxic fumes can drastically reduce the oxygen-carrying capacity of the blood, causing tissue hypoxia and central nervous system paralysis. Furthermore, the dense smoke completely obscures vision, making it difficult for miners to identify escape routes and exits, greatly increasing the risk of being trapped. Summary of the Invention
[0003] The purpose of this invention is to provide a low-smoke, low-toxicity, rubber-faced solid flame-retardant conveyor belt for coal mines and its preparation method in order to solve the above-mentioned problems.
[0004] The present invention achieves the above objectives through the following technical solutions:
[0005] This invention provides a low-smoke, low-toxicity rubber-faced solid woven flame-retardant conveyor belt for coal mines. The rubber-faced solid woven flame-retardant conveyor belt uses a braided belt core as a skeleton, and a core paste layer is attached to both sides of the braided belt core using a coating process. Then, a flame-retardant rubber covering layer is formed on the surface of the core paste.
[0006] The core paste layer is obtained by cooling and shaping the core paste compound;
[0007] The flame-retardant rubber cover layer is obtained by cooling and shaping a flame-retardant rubber cover compound.
[0008] The core paste is prepared by weight of 35-45 parts polyvinyl chloride paste resin, 25-35 parts liquid nitrile rubber, 15-25 parts zinc stannate, 8-16 parts ferrocene, 12-18 parts ammonium molybdate, 40-45 parts castor seed oil, 10-16 parts decabromodiphenyl ether and 1-2 parts phosphite.
[0009] By weight, the materials used to prepare the flame-retardant rubber coating include 10-20 parts of PVC suspension resin, 80-90 parts of nitrile rubber powder, 6-12 parts of polypropylene short fiber, 4-8 parts of aluminum hydroxide, 10-15 parts of silica, 8-16 parts of zinc borate, 35-45 parts of dimethyl sebacate, 15-25 parts of zinc stannate, 8-16 parts of ferrocene, 12-18 parts of ammonium molybdate, 1-2 parts of glyceryl monostearate, and 1-2 parts of phosphite.
[0010] As a further optimization of the present invention, the woven core is composed of two layers of mesh woven tape. One layer is formed by warp pile, which is woven from pile warp into loops and then cut to form pile. The other layer is formed by weft pile, which is formed by the floating of cut pile weft.
[0011] As a further optimization of the present invention, the two-layer mesh woven tape is combined by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
[0012] As a further optimization of the present invention, the braided belt core uses industrial polyester filament as warp yarn and cotton yarn as weft yarn.
[0013] As a further optimization of the present invention, the cotton yarn is made of Xinjiang long-staple cotton.
[0014] As a further optimization of the present invention, the preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 80-100℃ for 2-4 hours; (ii) Put the mixed rubber into a mixer and stir at 550r / min for 2-5min, add castor seed oil and stir at 60r / min for 5-8min, add zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in sequence, and mix for 10-15min to obtain the mixed rubber; (iii) Mix liquid nitrile rubber and polyvinyl chloride paste resin in a mixer at 45℃ and stir at 60r / min for 15-20min, add a portion of phosphite and stir at 60r / min for 15-20min to obtain the core paste.
[0015] As a further optimization of the present invention, the preparation process of flame-retardant rubber covering compound is as follows: (i) At 160°C, aluminum hydroxide and zinc borate are added to PVC suspension resin at a stirring speed of 35 r / min and stirred for 10 min. Silica, zinc stannate, ferrocene, and ammonium molybdate are added at a stirring speed of 25 r / min and stirred for 10 min. The mixture is then stirred at 15 r / min for 10 min to obtain flame-retardant rubber covering compound. Glyceryl monostearate and a portion of phosphite are added and placed in a planetary mixer. The temperature is lowered to 40-50°C and nitrile rubber powder and polypropylene short fibers are added and stirred at 25 r / min for 45-60 min. Dimethyl sebacate is added at 1200-1500 r / min and stirred for 45-60 min to obtain the base compound.
[0016] This invention also provides a method for preparing a low-smoke, low-toxicity rubber-faced solid-core flame-retardant conveyor belt for coal mines, comprising the following steps:
[0017] S1, inject the core paste into the impregnation tank and store it at a constant temperature of 60-80℃;
[0018] S2, Immerse the braided core into the impregnation tank for 40-60 minutes. After impregnation, the braided core enters the plasticizing box at a plasticizing temperature of 170-190℃ and is removed after 3-8 minutes to obtain the strip blank.
[0019] S3, flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank through an extruder at an extrusion die temperature of 160-170℃, an extrusion pressure of 8-15MPa, and a traction speed of 0.6-1.3m / min to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0020] The beneficial effects of this invention are as follows: This invention uses a woven belt core as a skeleton, employs a coating process to attach a core paste layer to both sides of the woven belt core, and then forms a flame-retardant rubber covering layer on the surface of the core paste. The woven belt core is composed of two layers of mesh woven belts, which can improve adhesion and adhesion effect when impregnating the core paste rubber, resulting in better physical and mechanical properties for the solid woven flame-retardant conveyor belt. The addition of zinc stannate, ferrocene, and ammonium molybdate smoke-suppressing components, through the synergistic effect of flame retardancy and smoke suppression, primarily using a condensed phase flame-retardant mechanism, results in a lower smoke density and lower toxicity index in fires, improving the survival rate of workers in coal mine fires. Detailed Implementation
[0021] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0022] Unless otherwise specified, all methods used in this invention are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products.
[0023] The polyvinyl chloride paste resin used in this invention is of the type Shenhua P450; the PVC suspension resin used in this invention is of the type Shenhua PSL-31.
[0024] Example 1
[0025] The woven core is composed of two layers of mesh woven tape. One layer uses warp pile, which is woven from pile warp into loops and then cut to form pile. The other layer uses weft pile, which is formed by the floating of cut pile weft. Industrial polyester filament is used as warp yarn and cotton yarn is used as weft yarn (the cotton yarn is selected from Xinjiang long-staple cotton).
[0026] The two-layer mesh woven tape composite is made by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
[0027] The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 80°C for 2-4 hours; (ii) Put the mixed rubber into a mixer and stir at 550r / min for 2min, add 40 parts of castor seed oil and stir at 60r / min for 5-8min, then add 15 parts of zinc stannate, 8 parts of ferrocene, 12 parts of ammonium molybdate and 10 parts of decabromodiphenyl ether in sequence, and mix for 10min to obtain the mixed rubber; (iii) Mix 25 parts of liquid nitrile rubber and 35 parts of polyvinyl chloride paste resin in a mixer at 45°C and stir at 60r / min for 15min, add 1 part of phosphite and stir at 60r / min for 15min to obtain the core paste.
[0028] The preparation process of flame-retardant rubber covering compound is as follows: (I) At 160℃, 10 parts of PVC suspension resin are added to 4 parts of aluminum hydroxide and 8 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 10 parts of silica, 15 parts of zinc stannate, 8 parts of ferrocene and 12 parts of ammonium molybdate are added and stirred for 10min. Stirring at 15r / min for 10min yields flame-retardant rubber covering compound. 1 part of glyceryl monostearate and 1 part of phosphite are added and placed in a planetary mixer. When the temperature drops to 40℃, 80 parts of nitrile rubber powder and 6 parts of polypropylene short fiber are added and stirred at 25r / min for 45min. 35 parts of dimethyl sebacate are added and stirred at 1200r / min for 45min to obtain the base compound.
[0029] The core paste material is injected into the impregnation tank and stored at a constant temperature of 70°C.
[0030] The braided strip core is immersed in the impregnation tank for 50 minutes. After impregnation, the braided strip core is placed in the plasticizing box at a plasticizing temperature of 180℃. After 6 minutes, it is taken out to obtain the strip blank.
[0031] Flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank using an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 10MPa, and the traction speed is 0.8m / min, to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0032] Example 2
[0033] The woven core is composed of two layers of mesh woven tape. One layer uses warp pile, which is woven from pile warp into loops and then cut to form pile. The other layer uses weft pile, which is formed by the floating of cut pile weft. Industrial polyester filament is used as warp yarn and cotton yarn is used as weft yarn (the cotton yarn is selected from Xinjiang long-staple cotton).
[0034] The two-layer mesh woven tape composite is made by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
[0035] The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 90°C for 3 hours; (ii) Put the mixed rubber into a mixer and stir at 550 r / min for 4 min, add 42 parts of castor seed oil and stir at 60 r / min for 6 min, then add 20 parts of zinc stannate, 12 parts of ferrocene, 16 parts of ammonium molybdate and 12 parts of decabromodiphenyl ether in sequence, and mix for 12 min to obtain the mixed rubber; (iii) Mix 30 parts of liquid nitrile rubber and 40 parts of polyvinyl chloride paste resin in a mixer at 45°C and stir at 60 r / min for 18 min, add 2 parts of phosphite and stir at 60 r / min for 18 min to obtain the core paste.
[0036] The preparation process of flame-retardant rubber covering compound is as follows: (I) At 160℃, 15 parts of PVC suspension resin are added to 6 parts of aluminum hydroxide and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 12 parts of silica, 20 parts of zinc stannate, 12 parts of ferrocene and 16 parts of ammonium molybdate are added and stirred for 10min. After stirring at 15r / min for 10min, flame-retardant rubber covering compound is obtained. 2 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. When the temperature drops to 45℃, 70 parts of nitrile rubber powder and 10 parts of polypropylene short fiber are added and stirred at 25r / min for 55min. 40 parts of dimethyl sebacate are added and stirred at 1350r / min for 55min to obtain the base compound.
[0037] The core paste material is injected into the impregnation tank and stored at a constant temperature of 70°C.
[0038] The braided strip core is immersed in the impregnation tank for 50 minutes. After impregnation, the braided strip core is placed in the plasticizing box at a plasticizing temperature of 180℃. After 6 minutes, it is taken out to obtain the strip blank.
[0039] Flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank using an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 10MPa, and the traction speed is 0.8m / min, to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0040] Example 3
[0041] The woven core is composed of two layers of mesh woven tape. One layer uses warp pile, which is woven from pile warp into loops and then cut to form pile. The other layer uses weft pile, which is formed by the floating of cut pile weft. Industrial polyester filament is used as warp yarn and cotton yarn is used as weft yarn (the cotton yarn is selected from Xinjiang long-staple cotton).
[0042] The two-layer mesh woven tape composite is made by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
[0043] The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 100°C for 4 hours; (ii) Put the mixed rubber into a mixer and stir at 550 r / min for 5 min, add 45 parts of castor seed oil and stir at 60 r / min for 8 min, then add 25 parts of zinc stannate, 16 parts of ferrocene, 18 parts of ammonium molybdate and 16 parts of decabromodiphenyl ether in sequence, and mix for 15 min to obtain the mixed rubber; (iii) Mix 35 parts of liquid nitrile rubber and 45 parts of polyvinyl chloride paste resin in a mixer at 45°C and stir at 60 r / min for 20 min, add 2 parts of phosphite and stir at 60 r / min for 20 min to obtain the core paste.
[0044] The preparation process of flame-retardant rubber covering compound is as follows: (I) At 160℃, 20 parts of PVC suspension resin are added to 8 parts of aluminum hydroxide and 16 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 15 parts of silica, 25 parts of zinc stannate, 16 parts of ferrocene and 18 parts of ammonium molybdate are added and stirred for 10min. After stirring at 15r / min for 10min, flame-retardant rubber covering compound is obtained. 2 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. When the temperature drops to 50℃, 90 parts of nitrile rubber powder and 12 parts of polypropylene short fiber are added and stirred at 25r / min for 60min. 45 parts of dimethyl sebacate are added and stirred at 1500r / min for 60min to obtain the base compound.
[0045] The core paste material is injected into the impregnation tank and stored at a constant temperature of 70°C.
[0046] The braided strip core is immersed in the impregnation tank for 50 minutes. After impregnation, the braided strip core is placed in the plasticizing box at a plasticizing temperature of 180℃. After 6 minutes, it is taken out to obtain the strip blank.
[0047] Flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank using an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 10MPa, and the traction speed is 0.8m / min, to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0048] Comparative Example 1
[0049] The woven core is composed of two layers of mesh woven tape. One layer uses warp pile, which is woven from pile warp into loops and then cut to form pile. The other layer uses weft pile, which is formed by the floating of cut pile weft. Industrial polyester filament is used as warp yarn and cotton yarn is used as weft yarn (the cotton yarn is selected from Xinjiang long-staple cotton).
[0050] The two-layer mesh woven tape composite is made by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
[0051] The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 90°C for 3 hours; (ii) Put the mixed rubber into a mixer and stir at 550 r / min for 4 min, add 42 parts of castor seed oil and stir at 60 r / min for 6 min, then add 32 parts of zinc stannate, 16 parts of ammonium molybdate and 12 parts of decabromodiphenyl ether in sequence, and mix for 12 min to obtain the mixed rubber; (iii) Mix 30 parts of liquid nitrile rubber and 40 parts of polyvinyl chloride paste resin in a mixer at 45°C and stir at 60 r / min for 18 min, add 2 parts of phosphite and stir at 60 r / min for 18 min to obtain the core paste.
[0052] The preparation process of flame-retardant rubber covering compound is as follows: (I) At 160℃, 15 parts of PVC suspension resin are added to 6 parts of aluminum hydroxide and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 12 parts of silica, 20 parts of zinc stannate, 12 parts of ferrocene and 16 parts of ammonium molybdate are added and stirred for 10min. After stirring at 15r / min for 10min, flame-retardant rubber covering compound is obtained. 2 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. When the temperature drops to 45℃, 70 parts of nitrile rubber powder and 10 parts of polypropylene short fiber are added and stirred at 25r / min for 55min. 40 parts of dimethyl sebacate are added and stirred at 1350r / min for 55min to obtain the base compound.
[0053] The core paste material is injected into the impregnation tank and stored at a constant temperature of 70°C.
[0054] The braided strip core is immersed in the impregnation tank for 50 minutes. After impregnation, the braided strip core is placed in the plasticizing box at a plasticizing temperature of 180℃. After 6 minutes, it is taken out to obtain the strip blank.
[0055] Flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank using an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 10MPa, and the traction speed is 0.8m / min, to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0056] Comparative Example 2
[0057] The woven core is composed of two layers of mesh woven tape. One layer uses warp pile, which is woven from pile warp into loops and then cut to form pile. The other layer uses weft pile, which is formed by the floating of cut pile weft. Industrial polyester filament is used as warp yarn and cotton yarn is used as weft yarn (the cotton yarn is selected from Xinjiang long-staple cotton).
[0058] The two-layer mesh woven tape composite is made by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
[0059] The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 90°C for 3 hours; (ii) Put the mixed rubber into a mixer and stir at 550 r / min for 4 min, add 42 parts of castor seed oil and stir at 60 r / min for 6 min, then add 32 parts of ferrocene, 16 parts of ammonium molybdate and 12 parts of decabromodiphenyl ether in sequence, and mix for 12 min to obtain the mixed rubber; (iii) Mix 30 parts of liquid nitrile rubber and 40 parts of polyvinyl chloride paste resin in a mixer at 45°C and stir at 60 r / min for 18 min, add 2 parts of phosphite and stir at 60 r / min for 18 min to obtain the core paste.
[0060] The preparation process of flame-retardant rubber covering compound is as follows: (I) At 160℃, 15 parts of PVC suspension resin are added to 6 parts of aluminum hydroxide and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 12 parts of silica, 20 parts of zinc stannate, 12 parts of ferrocene and 16 parts of ammonium molybdate are added and stirred for 10min. After stirring at 15r / min for 10min, flame-retardant rubber covering compound is obtained. 2 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. When the temperature drops to 45℃, 70 parts of nitrile rubber powder and 10 parts of polypropylene short fiber are added and stirred at 25r / min for 55min. 40 parts of dimethyl sebacate are added and stirred at 1350r / min for 55min to obtain the base compound.
[0061] The core paste material is injected into the impregnation tank and stored at a constant temperature of 70°C.
[0062] The braided strip core is immersed in the impregnation tank for 50 minutes. After impregnation, the braided strip core is placed in the plasticizing box at a plasticizing temperature of 180℃. After 6 minutes, it is taken out to obtain the strip blank.
[0063] Flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank using an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 10MPa, and the traction speed is 0.8m / min, to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0064] Comparative Example 3
[0065] The core of the woven tape is a mesh woven tape, which is made by weaving the pile warp into loops and then cutting them to form pile. Industrial polyester filament is used as the warp yarn and cotton yarn is used as the weft yarn (the cotton yarn is Xinjiang long-staple cotton).
[0066] The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 90°C for 3 hours; (ii) Put the mixed rubber into a mixer and stir at 550 r / min for 4 min, add 42 parts of castor seed oil and stir at 60 r / min for 6 min, then add 20 parts of zinc stannate, 12 parts of ferrocene, 16 parts of ammonium molybdate and 12 parts of decabromodiphenyl ether in sequence, and mix for 12 min to obtain the mixed rubber; (iii) Mix 30 parts of liquid nitrile rubber and 40 parts of polyvinyl chloride paste resin in a mixer at 45°C and stir at 60 r / min for 18 min, add 2 parts of phosphite and stir at 60 r / min for 18 min to obtain the core paste.
[0067] The preparation process of flame-retardant rubber covering compound is as follows: (I) At 160℃, 15 parts of PVC suspension resin are added to 6 parts of aluminum hydroxide and 12 parts of zinc borate at a stirring speed of 35r / min and stirred for 10min. At a stirring speed of 25r / min, 12 parts of silica, 20 parts of zinc stannate, 12 parts of ferrocene and 16 parts of ammonium molybdate are added and stirred for 10min. After stirring at 15r / min for 10min, flame-retardant rubber covering compound is obtained. 2 parts of glyceryl monostearate and 2 parts of phosphite are added and placed in a planetary mixer. When the temperature drops to 45℃, 70 parts of nitrile rubber powder and 10 parts of polypropylene short fiber are added and stirred at 25r / min for 55min. 40 parts of dimethyl sebacate are added and stirred at 1350r / min for 55min to obtain the base compound.
[0068] The core paste material is injected into the impregnation tank and stored at a constant temperature of 70°C.
[0069] The braided strip core is immersed in the impregnation tank for 50 minutes. After impregnation, the braided strip core is placed in the plasticizing box at a plasticizing temperature of 180℃. After 6 minutes, it is taken out to obtain the strip blank.
[0070] Flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank using an extruder. The extrusion die temperature is 165℃, the extrusion pressure is 10MPa, and the traction speed is 0.8m / min, to obtain a rubber-faced solid core flame-retardant conveyor belt.
[0071] Performance testing
[0072] According to MT / T 668-2019 "Flame-retardant steel wire rope core conveyor belts, solid fabric flame-retardant conveyor belts and solid plastic flame-retardant conveyor belts for coal mines", the performance of the rubber-faced solid flame-retardant conveyor belts prepared by the methods of Examples 1-3 and Comparative Examples 1-3 was tested, and the test results are shown in Table 1.
[0073] Table 1
[0074]
[0075] As can be seen from Table 1, Examples 1-3 in the experimental group have better physical and mechanical properties, and Examples 1-3 have shorter open flame burning time and flameless burning time in the alcohol torch burning test.
[0076] The smoke performance of the rubber-faced solid woven flame-retardant conveyor belts prepared by the methods of Examples 1-3 and Comparative Examples 1-3 was tested according to GB / T8323.2-2008, and the test results are shown in Table 2. The lethal toxicity of the rubber-faced solid woven flame-retardant conveyor belts prepared by the methods of Examples 1-3 and Comparative Examples 1-3 was evaluated according to GB / T8323.2-2008, and the evaluation results are shown in Table 2.
[0077] Table 2
[0078]
[0079] As can be seen from Table 2, the smoke concentration in Examples 1-3 of the experimental group was low, and the ability to block light was not strong. The Ds (specific optical density) was in the relatively good low smoke range. In contrast, the smoke concentration in Comparative Examples 1-3 was moderate, and the ability to block light was slightly stronger. The toxicity index of Examples 1-3 in the experimental group was all < 1.0, while the toxicity index of Comparative Examples 1-3 was all > 1.0. This means that under the test conditions, the toxic substances in Comparative Examples 1-3 could cause the death of half of the animals within 30 minutes.
[0080] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.
Claims
1. A low-smoke, low-toxicity, solid-core flame-retardant conveyor belt with rubber surface for coal mines, characterized in that, The rubber-faced solid core flame-retardant conveyor belt is made of a braided belt core as a skeleton, and a core paste layer is attached to both sides of the braided belt core by a coating process. Then, a flame-retardant rubber covering layer is formed on the surface of the core paste. The core paste layer is obtained by cooling and shaping the core paste compound; The flame-retardant rubber cover layer is obtained by cooling and shaping a flame-retardant rubber cover compound. The core paste is prepared by weight of 35-45 parts polyvinyl chloride paste resin, 25-35 parts liquid nitrile rubber, 15-25 parts zinc stannate, 8-16 parts ferrocene, 12-18 parts ammonium molybdate, 40-45 parts castor seed oil, 10-16 parts decabromodiphenyl ether and 1-2 parts phosphite. By weight, the materials used to prepare the flame-retardant rubber coating include 10-20 parts of PVC suspension resin, 80-90 parts of nitrile rubber powder, 6-12 parts of polypropylene short fiber, 4-8 parts of aluminum hydroxide, 10-15 parts of silica, 8-16 parts of zinc borate, 35-45 parts of dimethyl sebacate, 15-25 parts of zinc stannate, 8-16 parts of ferrocene, 12-18 parts of ammonium molybdate, 1-2 parts of glyceryl monostearate, and 1-2 parts of phosphite.
2. The low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines according to claim 1, characterized in that, The woven core is composed of two layers of mesh woven tape. One layer uses warp pile, which is woven from the pile warp into loops and then cut to form pile. The other layer uses weft pile, which is formed by the weft of the cut pile weft floating long.
3. The low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines according to claim 2, characterized in that, The two-layer mesh woven tape composite is made by repeatedly piercing the tape vertically with a needle. When the needle descends, it carries down some fibers from the upper mesh, and when it rises, the barbs leave these fibers in the lower mesh.
4. The low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines with rubber facing according to claim 3, characterized in that, The woven belt core uses industrial polyester filament as warp yarn and cotton yarn as weft yarn.
5. The low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines according to claim 4, characterized in that, The cotton yarn is made from Xinjiang long-staple cotton.
6. The low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines with rubber facing according to claim 1, characterized in that, The preparation process of the core paste is as follows: (i) Dry zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in a forced-air drying oven at 80-100℃ for 2-4 hours; (ii) Put the mixed rubber into a mixer and stir at 550r / min for 2-5min, add castor seed oil and stir at 60r / min for 5-8min, add zinc stannate, ferrocene, ammonium molybdate and decabromodiphenyl ether in sequence, and mix for 10-15min to obtain the mixed rubber; (iii) Mix liquid nitrile rubber and polyvinyl chloride paste resin in a mixer at 45℃ and stir at 60r / min for 15-20min, add phosphite and stir at 60r / min for 15-20min to obtain the core paste.
7. The low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines with rubber facing according to claim 1, characterized in that, The preparation process of the flame-retardant rubber covering compound is as follows: (i) At 160℃, aluminum hydroxide and zinc borate are added to PVC suspension resin at a stirring speed of 35r / min and stirred for 10min. Silica, zinc stannate, ferrocene, and ammonium molybdate are added at a stirring speed of 25r / min and stirred for 10min. The mixture is then stirred at 15r / min for 10min to obtain the flame-retardant rubber covering compound. Glyceryl monostearate and a certain amount of phosphite are added and placed in a planetary mixer. When the temperature drops to 40-50℃, nitrile rubber powder and polypropylene short fibers are added and stirred at 25r / min for 45-60min. Dimethyl sebacate is added at 1200-1500r / min and stirred for 45-60min to obtain the base compound.
8. A method for preparing a low-smoke, low-toxicity, solid-core flame-retardant conveyor belt for coal mines according to any one of claims 1-7, characterized in that, Includes the following steps: S1, inject the core paste into the impregnation tank and store it at a constant temperature of 40-50℃; S2, Immerse the braided core into the impregnation tank for 40-60 minutes. After impregnation, the braided core enters the plasticizing box at a plasticizing temperature of 170-190℃ and is removed after 3-8 minutes to obtain the strip blank. S3, flame-retardant rubber covering material is extruded and bonded to the outside of the belt blank through an extruder at an extrusion die temperature of 160-170℃, an extrusion pressure of 8-15MPa, and a traction speed of 0.6-1.3m / min to obtain a rubber-faced solid core flame-retardant conveyor belt.