A flame-retardant sponge pad and its preparation method

Abstract

The present invention discloses a flame-retardant sponge pad, which relates to the technical field of sponge pad processing, and includes a flame-retardant cloth composite layer, a nano sponge core layer and a rubber composite layer. The flame-retardant cloth composite layer, the nano sponge core layer and the rubber composite layer are arranged in sequence from top to bottom; the flame-retardant cloth composite layer includes the following raw materials by weight: one part of flame-retardant cloth, 20-40 parts of natural rubber, 5-10 parts of stearic acid, 15-30 parts of tetrapropyl fluororubber, 10-15 parts of nitrile rubber, 1-3 parts of sulfur powder, and 2-4 parts of anti-scorching agent; the nano sponge core layer includes the following raw materials by weight: 30-60 parts of polyvinyl alcohol, 10-20 parts of sodium dodecyl sulfate, 3-6 parts of silicon oxide, 2-4 parts of dextran, 4-8 parts of flame retardant, and 2.5-5 parts of heat-resistant toughening agent; in the present invention, it has a flame-retardant effect, has a low flammability, and will not catch fire due to overheating during use, improving the safety of the sponge pad during use.

Description

Technical Field

[0001] The present invention relates to the technical field of sponge pad processing, and particularly relates to a flame-retardant sponge pad and a preparation method thereof. Background Art

[0002] A sponge pad is a fully closed foam plastic. The sponge pad has characteristics such as heat preservation, heat insulation, less water absorption, and light specific gravity. Sponge pads are usually used in electronic appliances, machinery, toys; sponge gaskets, sponge strips, etc.

[0003] Due to its excellent comfort performance, polyurethane slow-rebound foam has been widely used in fields such as household goods, automobiles, shoe materials, and medical devices. Polyurethane rebound foam has a relatively high comfort performance due to its unique molecular structure. When subjected to a certain pressure, the polyurethane rebound foam will change its shape with the pressure, making the pressure evenly distributed, reducing local stress points. After the pressure is released, its shape slowly returns to its original state. However, due to its own closed-cell structure, the air permeability and damping sound absorption performance of polyurethane slow-rebound foam are poor.

[0004] The existing Chinese patent (publication number: CN106220816A) proposes a polyurethane foamed sponge pad with good microporous air permeability, which is prepared from the following raw materials in parts by weight: microcrystalline cellulose, soybean oil, diethylene glycol, potassium hydroxide, polyether polyol, foaming agent, foam stabilizer, catalyst, toluene diisocyanate, distilled water, nano magnesium hydroxide, acrylic acid, polyacrylamide, polyvinyl alcohol, polyvinyl butyral, isopropanol, glycerol; the prepared foamed sponge has the effects of low raw material loss, simple process, high product stability, high mechanical strength, strong tensile property, good flame retardancy, and can reduce the fire hazard.

[0005] The existing Chinese patent (publication number: CN106317443A) proposes a preparation process for a bamboo charcoal sponge pad, which includes the following process steps: a. Place the bamboo charcoal in a crusher and crush it into bamboo charcoal powder, and the particle size of the bamboo charcoal powder is 1000 - 1500 mesh; b. Pour the bamboo charcoal powder, polyester, polyether, silicone oil, foaming agent, and water into a mixer and stir. The weight parts of each material are: bamboo charcoal powder 5% - 20%, polyester 20% - 40%, polyether 20% - 40%, silicone oil 5% - 10%, foaming agent 3% - 5%, water 20% - 40%; c. Pour the uniformly stirred bamboo charcoal powder, polyester, polyether, silicone oil, foaming agent, and water into a molding mold, and the molding mold is heated and pressurized, and the mixture foams and forms a bamboo charcoal sponge pad, which can mix the bamboo charcoal material into the sponge material, that is, can effectively enhance the moisture absorption and dehumidification ability of the sponge pad, and can effectively simplify the structure of the mattress.

[0006] The above-mentioned sponge pad has the following disadvantages when in use: The sponge pad is usually made of organic flammable materials, so it does not have a flame retardant effect, has a high flammability, and is prone to burning due to overheating during use, resulting in potential safety hazards when using the sponge pad. Therefore, we propose a flame retardant sponge pad and its preparation method to solve the above problems. Summary of the Invention

[0007] The present invention provides a flame retardant sponge pad and its preparation method, which solves the technical problem that the sponge pad is usually made of organic flammable materials, so it does not have a flame retardant effect, has a high flammability, and is prone to burning due to overheating during use, resulting in potential safety hazards when using the sponge pad.

[0008] To solve the above technical problems, a flame retardant sponge pad provided by the present invention includes a flame retardant cloth composite layer, a nano sponge core layer, and a rubber composite layer, and the flame retardant cloth composite layer, the nano sponge core layer, and the rubber composite layer are arranged in sequence from top to bottom;

[0009] The flame retardant cloth composite layer includes the following raw materials by weight: 1 part of flame retardant cloth, 20 - 40 parts of natural rubber, 5 - 10 parts of stearic acid, 15 - 30 parts of tetrapropyl fluororubber, 10 - 15 parts of nitrile rubber, 1 - 3 parts of sulfur powder, and 2 - 4 parts of scorch retarder;

[0010] The nano sponge core layer includes the following raw materials by weight: 30 - 60 parts of polyvinyl alcohol, 10 - 20 parts of sodium dodecyl sulfate,

[0010] 3 - 6 parts of silicon dioxide, 2 - 4 parts of dextran, 4 - 8 parts of flame retardant, and 2.5 - 5 parts of heat-resistant toughening agent;

[0011] The rubber composite layer includes the following raw materials by weight: 15 - 35 parts of cis-butadiene rubber, 4 - 12 parts of natural rubber, 4 - 12 parts of solution-polymerized styrene-butadiene rubber, and 1.5 - 2 parts of elastic modifier.

[0012] A preparation method of a flame retardant sponge pad includes the following steps:

[0013] S1. Prepare the flame retardant cloth composite layer: Stir natural rubber, stearic acid, tetrapropyl fluororubber, and nitrile rubber evenly, then add water to dilute to a concentration of 10% - 25% to form a mixed solution. Slowly add sulfur powder to the mixed solution, stir evenly, and form a dilution solution;

[0014] Then add a scorch retarder to the dilution solution, control the stirring speed at 500 - 800 r / min, and stir for 20 min to obtain a slurry;

[0015] The obtained slurry is introduced and placed on the flame-retardant cloth, and a slurry layer with a thickness of 0.4 - 0.8 mm is formed on the surface of the flame-retardant cloth to obtain a flame-retardant cloth composite blank; the slurry is coated on the flame-retardant cloth composite blank by a continuous doctor blade method to form a flame-retardant cloth composite layer with a thickness of 1.5 - 2.0 mm;

[0016] S2. Prepare the nano-sponge core layer: Add polyvinyl alcohol to deionized water, stir evenly, add sodium dodecyl sulfate and dissolve it to prepare a uniform dispersion phase solution;

[0017] Add silicon oxide to the dispersion phase solution, and perform ultrasonic treatment for 10 min to make it evenly dispersed in the dispersion phase solution;

[0018] Add dextran, flame retardant and heat-resistant toughening agent to the dispersion phase solution, stir evenly, place it in a constant temperature oscillator, and carry out a constant temperature oscillation curing process, with constant temperature oscillation at 40 °C for 3 h;

[0019] Pour the crosslinked and cured dispersion phase solution into a mold, place it in a vacuum chamber for degassing for 15 min, and finally dry it in an oven at 50 °C to obtain the nano-sponge core layer;

[0020] S3. Prepare the rubber composite layer: Add cis-butadiene rubber, natural rubber and solution-polymerized styrene-butadiene rubber to a fusion machine for fusion treatment to obtain a heat-conducting composition;

[0021] Add the above heat-conducting composition and elastic modifier to the matrix, stir evenly in a stirring device, and then obtain the rubber composite layer after calendering and vulcanization by a calender;

[0022] S4. Cutting: Cut the flame-retardant cloth composite layer and the rubber composite layer into block structures with the same shape as the nano-sponge core layer and with both length and width greater than the nano-sponge core layer by 1.5 mm;

[0023] S5. Molding; Place the rubber composite layer (3) on a hot pressing device, then sequentially place the nano-sponge core layer and the flame-retardant cloth composite layer on the rubber composite layer, and align the edges of the flame-retardant cloth composite layer and the rubber composite layer. Use the hot pressing device to press the edges of the flame-retardant cloth composite layer and the rubber composite layer, so that the edges of the flame-retardant cloth composite layer and the rubber composite layer are melted and integrated to obtain the finished flame-retardant sponge pad.

[0024] Preferably, in step S, the hot pressing equipment used to form the flame-retardant sponge pad includes a forming table, a supporting table, a support rod, a top plate, a pressure cylinder and a hot pressing assembly, the supporting table can be horizontally slidably arranged on the top of the forming table, the support rod is fixedly installed on the top surface of the forming table, the top plate is fixedly installed on the top of the support rod, the pressure cylinder is fixedly installed on the top surface of the top plate, the hot pressing assembly can be vertically slidably arranged on the support rod, the telescopic end of the pressure cylinder is fixedly connected to the center of the top surface of the hot pressing assembly, the hot pressing assembly includes a movable plate slidably arranged on the support rod, a high-temperature insulation frame plate is fixedly installed on the bottom surface of the movable plate, a high-temperature electric heating tube is arranged inside the high-temperature insulation frame plate, a high-temperature heating plate is also fixedly installed on the high-temperature insulation frame plate, and a heat-sealing plate is fixedly installed on the outer surface of the high-temperature heating plate.

[0025] Preferably, the high-temperature electric heating tube is arranged in a serpentine shape inside the high-temperature insulation frame plate. The material of the high-temperature electric heating tube is copper. A temperature sensor is fixedly installed on the side wall of the high-temperature insulation frame plate. There is a gap between the temperature sensor and the high-temperature electric heating tube.

[0026] Preferably, a movable groove is provided on the top surface of the forming table, a driving screw is rotatably installed inside the movable groove, a driving block is threadedly connected to the driving screw, the top surface of the driving block is fixedly connected to the center of the bottom surface of the supporting platform, a driving motor is fixedly installed on the side wall of the forming table, and the driving end of the driving motor is fixedly connected to one end of the driving screw.

[0027] Preferably, the top surface of the forming table is symmetrically provided with guide grooves, the guide grooves are distributed along both sides of the movable groove, and guide blocks are slidably provided inside the guide grooves, and the guide blocks are fixedly connected to the bottom surface of the supporting platform.

[0028] Preferably, the supporting platform is provided with a positioning component for fixing the sponge during the sponge pad forming process, the positioning component includes a bidirectional screw rod rotatably installed inside the supporting platform, a threaded seat is threadedly connected to the bidirectional screw rod, a servo motor is fixedly installed inside the supporting platform, a synchronous wheel is fixedly installed on the driving end of the servo motor and the middle outer wall of the bidirectional screw rod, a synchronous belt is connected for transmission between the two synchronous wheels, a sliding rod is fixedly installed on the opposite side of the two threaded seats, a connecting frame is fixedly installed on the end of the sliding rod extending to the outside of the supporting platform, and a limiting plate is fixedly installed on the connecting frame.

[0029] Preferably, a through hole is provided on the side wall of the supporting platform, the sliding rod passes through the through hole and extends to the outside of the supporting platform, and the outer diameter of the sliding rod is smaller than the inner diameter of the through hole.

[0030] Preferably, the positioning assembly further includes small gears fixedly installed at both ends of the bidirectional lead screw. A large gear is rotatably installed on the side wall of the bearing platform and meshed with the small gear. A transmission gear is coaxially connected to the front side of the large gear. Transmission racks are meshed with both the upper and lower parts of the transmission gear. Side plates are slidably arranged at the four corners of the top surface of the bearing platform, and the transmission racks are fixedly connected to the side plates.

[0031] Compared with the related art, a flame-retardant sponge pad and its preparation method provided by the present invention have the following beneficial effects:

[0032] In the present invention, the rubber composite layer is placed on a hot-pressing device, and then the nano-sponge core layer and the flame-retardant cloth composite layer are sequentially placed on the rubber composite layer, and the edges of the flame-retardant cloth composite layer and the rubber composite layer are aligned. The hot-pressing device is used to press the edges of the flame-retardant cloth composite layer and the rubber composite layer, so that the edges of the flame-retardant cloth composite layer and the rubber composite layer are melted into one body, and the finished product of the flame-retardant sponge pad is obtained. This sponge pad has a flame-retardant effect, has low flammability, and will not catch fire due to overheating during use, improving the safety of the sponge pad during use.

[0033] In the present invention, the servo motor can drive the synchronous wheel to rotate. The synchronous wheel drives the bidirectional lead screw to rotate through the synchronous belt. The bidirectional lead screw drives the threaded seat threaded thereon to move horizontally. The threaded seat drives the sliding rod to move, and the sliding rod drives the connecting frame and the limiting plate to move. The sponge pad can be clamped and fixed by the cooperation of the two limiting plates. By rotating the bidirectional lead screw, the small gear can be driven to rotate. The small gear drives the large gear meshed with it to rotate. The large gear drives the coaxially arranged transmission gear to rotate. The transmission gear drives the transmission rack meshed with it to move horizontally. The transmission rack drives the side plate to further clamp and fix the sponge pad. It can be adjusted according to the size of the sponge pad from multiple directions, and then the sponge pad on the bearing platform is positioned, so that the positioning effect of the sponge pad is better and it is not easy to shift, adapting to fixing sponge pads of various sizes. Description of the Drawings

[0034] Figure 1 is a schematic structural diagram of a flame-retardant sponge pad;

[0035] Figure 2 is a three-dimensional schematic diagram of a hot-pressing device in a preparation method of a flame-retardant sponge pad;

[0036] Figure 3 is a three-dimensional schematic diagram of a hot-pressing device in a preparation method of a flame-retardant sponge pad;

[0037] Figure 4 is a cross-sectional schematic diagram of a hot-pressing device in a preparation method of a flame-retardant sponge pad;

[0038] Figure 5It is a schematic three-dimensional structure diagram of a bearing table in a hot pressing device;

[0039] Figure 6 It is a schematic cross-sectional structure diagram of a bearing table in a hot pressing device;

[0040] Figure 7 It is a schematic three-dimensional structure diagram of a hot pressing component in a hot pressing device;

[0041] Figure 8 It is a schematic cross-sectional structure diagram of a hot pressing component in a hot pressing device.

[0042] Reference numerals in the figure: 1, flame retardant cloth composite layer; 2, nano sponge core layer; 3, rubber composite layer; 4, forming table; 5, bearing table; 501, movable groove; 502, driving screw; 503, driving motor; 504, driving block; 6, support rod; 7, top plate; 8, pressing oil cylinder; 9, hot pressing component; 901, movable plate; 902, high-temperature heat insulation frame plate; 903, high-temperature electric heating tube; 904, high-temperature heating plate; 905, heat sealing plate; 906, temperature sensor; 10, positioning component; 101, bidirectional lead screw; 102, threaded seat; 103, servo motor; 104, synchronous pulley; 105, synchronous belt; 106, sliding rod; 107, connecting frame; 108, limiting plate; 109, small gear; 110, large gear; 111, transmission gear; 112, transmission rack; 113, side plate. Detailed implementation mode

[0043] The following details the implementation modes of the present invention. The examples of the implementation modes are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The implementation modes described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0044] Example 1, given by Figure 1 A flame retardant sponge pad includes a flame retardant cloth composite layer 1, a nano sponge core layer 2, and a rubber composite layer 3, and the flame retardant cloth composite layer 1, the nano sponge core layer 2, and the rubber composite layer 3 are arranged in sequence from top to bottom;

[0045] The flame retardant cloth composite layer 1 includes the following raw materials by weight: one part of flame retardant cloth, 20 - 40 parts of natural rubber, 5 - 10 parts of stearic acid, 15 - 30 parts of tetrapropyl fluororubber, 10 - 15 parts of nitrile rubber, 1 - 3 parts of sulfur powder, and 2 - 4 parts of anti-scorching agent;

[0046] The nano sponge core layer 2 includes the following raw materials by weight: 30 - 60 parts of polyvinyl alcohol, 10 - 20 parts of sodium dodecyl sulfate, 3 - 6 parts of silicon dioxide, 2 - 4 parts of dextran, 4 - 8 parts of flame retardant, and 2.5 - 5 parts of heat-resistant toughening agent;

[0047] The rubber composite layer 3 comprises raw materials in the following parts by weight: 15-35 parts of cis-butadiene rubber, 4-12 parts of natural rubber, 4-12 parts of solution-polymerized styrene-butadiene rubber, and 1.5-2 parts of elastic modifier.

[0048] Refer to Figures 1-8 , a preparation method of a flame-retardant sponge pad, comprising the following steps:

[0049] S1. Prepare the flame-retardant cloth composite layer 1: Stir natural rubber, stearic acid, tetrapropyl fluoride rubber, and nitrile rubber evenly, then add water to dilute to a concentration of 10%-25% to form a mixed solution. Slowly add sulfur powder to the mixed solution, stir evenly, and form a dilution solution;

[0050] Then add an anti-scorching agent to the dilution solution, control the stirring speed at 500-800 r / min, and stir for 20 min to obtain a slurry;

[0051] Introduce the obtained slurry onto the flame-retardant cloth, and form a slurry layer with a thickness of 0.4-0.8 mm on the surface of the flame-retardant cloth to obtain a flame-retardant cloth composite blank; Coating the slurry on the flame-retardant cloth composite blank by a continuous doctor blade method to form a flame-retardant cloth composite layer 1 with a thickness of 1.5-2.0 mm;

[0052] S2. Prepare the nano-sponge core layer 2: Add polyvinyl alcohol to deionized water, stir evenly, add sodium dodecyl sulfate to dissolve, and prepare a uniform dispersion phase solution;

[0053] Add silicon oxide to the dispersion phase solution, and perform ultrasonic treatment for 10 min to make it uniformly dispersed in the dispersion phase solution;

[0054] Add dextran, a flame retardant, and a heat-resistant toughening agent to the dispersion phase solution, stir evenly, place it in a constant temperature oscillator, and perform a constant temperature oscillation curing process, with constant temperature oscillation at 40°C for 3 h;

[0055] Pour the crosslinked and cured dispersion phase solution into a mold, place it in a vacuum chamber for degassing for 15 min, and finally dry it in an oven at 50°C to obtain the nano-sponge core layer 2;

[0056] S3. Prepare the rubber composite layer 3: Add cis-butadiene rubber, natural rubber, and solution-polymerized styrene-butadiene rubber to a fusion machine for fusion treatment to obtain a heat-conducting composition;

[0057] Add the above heat-conducting composition and elastic modifier to the matrix, stir evenly in a stirring device, and then obtain the rubber composite layer 3 after calendering and vulcanization by a calender;

[0058] S4. Cutting: Cut the flame-retardant cloth composite layer 1 and the rubber composite layer 3 into block structures with the same shape as the nano-sponge core layer 2 and with the length and width both greater than the length and width of the nano-sponge core layer 2 by 1.5 mm;

[0059] S5, Shaping: Place the rubber composite layer 3 on a hot pressing device, then sequentially place the nano sponge core layer 2 and the flame retardant fabric composite layer 1 on the rubber composite layer 3, and align the edges of the flame retardant fabric composite layer 1 and the rubber composite layer 3. Use the hot pressing device to press the edges of the flame retardant fabric composite layer 1 and the rubber composite layer 3, so that the edges of the flame retardant fabric composite layer 1 and the rubber composite layer 3 are melted and integrated to obtain the finished flame retardant sponge pad.

[0060] In step S5, the hot pressing device for shaping the flame retardant sponge pad includes a shaping table 4, a bearing table 5, a support rod 6, a top plate 7, a pressing oil cylinder 8, and a hot pressing assembly 9. The bearing table 5 is horizontally slidably arranged on the top of the shaping table 4. The support rod 6 is fixedly installed on the top surface of the shaping table 4. The top plate 7 is fixedly installed at the top of the support rod 6. The pressing oil cylinder 8 is fixedly installed on the top surface of the top plate 7. The hot pressing assembly 9 is vertically slidably arranged on the support rod 6. The telescopic end of the pressing oil cylinder 8 is fixedly connected to the center of the top surface of the hot pressing assembly 9. The hot pressing assembly 9 includes a movable plate 901 slidably arranged on the support rod 6. A high-temperature heat insulation frame plate 902 is fixedly installed on the bottom surface of the movable plate 901. A high-temperature electric heating tube 903 is arranged inside the high-temperature heat insulation frame plate 902. A high-temperature heating plate 904 is also fixedly installed on the high-temperature heat insulation frame plate 902. A heat sealing plate 905 is fixedly installed on the outer surface of the high-temperature heating plate 904.

[0061] During specific implementation, first place the rubber composite layer 3 on the hot pressing device, then sequentially place the nano sponge core layer 2 and the flame retardant fabric composite layer 1 on the rubber composite layer 3, and align the edges of the flame retardant fabric composite layer 1 and the rubber composite layer 3. The external oil supply assembly can supply hydraulic oil to the inside of the pressing oil cylinder 8, so that the pressing oil cylinder 8 can push the hot pressing assembly 9 to move downward. The high-temperature electric heating tube 903 and the high-temperature heating plate 904 can heat the heat sealing plate 905. After the heat sealing plate 905 is heated, it can heat the rubber composite layer 3, the nano sponge core layer 2, and the flame retardant fabric composite layer 1, thereby achieving the effect of high-temperature hot pressing. Use the hot pressing device to press the edges of the flame retardant fabric composite layer 1 and the rubber composite layer 3, so that the edges of the flame retardant fabric composite layer 1 and the rubber composite layer 3 are melted and integrated to obtain the finished flame retardant sponge pad.

[0062] The high-temperature electric heating tube 903 is arranged in a serpentine shape inside the high-temperature heat insulation frame plate 902. The material of the high-temperature electric heating tube 903 is copper. A temperature sensor 906 is fixedly installed on the side wall of the high-temperature heat insulation frame plate 902, and there is a gap between the temperature sensor 906 and the high-temperature electric heating tube 903.

[0063] In specific implementation, a high-temperature electric heating tube 903 and a temperature sensor 906 are provided in the high-temperature insulation frame plate 902, and the temperature sensor 906 is connected to an external intelligent temperature control instrument. The intelligent temperature control instrument controls the power on and off or the current size of the high-temperature electric heating tube 903 to control the temperature of the heat-sealed plate 905 within an appropriate range.

[0064] A movable groove 501 is formed on the top surface of the forming table 4. A driving screw 502 is rotatably mounted inside the movable groove 501. A driving block 504 is threadedly connected to the driving screw 502. The top surface of the driving block 504 is fixedly connected to the center of the bottom surface of the supporting platform 5. A driving motor 503 is fixedly mounted on the side wall of the forming table 4. The driving end of the driving motor 503 is fixedly connected to one end of the driving screw 502.

[0065] During specific implementation, the driving motor 503 can drive the driving screw 502 to rotate, and the driving screw 502 drives the driving block 504 threadedly connected to it to move horizontally inside the movable groove 501. During the movement of the driving block 504, the supporting platform 5 can be driven to move horizontally on the forming table 4, and then the supporting platform 5 can be driven to reach the bottom of the hot pressing component 9, so that the supporting platform 5 and the hot pressing component 9 are symmetrical.

[0066] The top surface of the forming table 4 is symmetrically provided with guide grooves, which are distributed along both sides of the movable groove 501. The inner portion of the guide groove is provided with a guide block which is fixedly connected to the bottom surface of the supporting platform 5.

[0067] During specific implementation, the cooperation between the guide block and the guide groove can guide the horizontal sliding of the carrier platform 5 , thereby improving the sliding stability of the carrier platform 5 .

[0068] A positioning assembly 10 for fixing the sponge during the sponge pad forming process is provided on the bearing platform 5. The positioning assembly 10 includes a bidirectional screw 101 rotatably mounted inside the bearing platform 5. A threaded seat 102 is threadedly connected to the bidirectional screw 101. A servo motor 103 is fixedly mounted inside the bearing platform 5. A synchronous wheel 104 is fixedly mounted on the driving end of the servo motor 103 and the outer wall of the middle part of the bidirectional screw 101. A synchronous belt 105 is connected between the two synchronous wheels 104. A sliding rod 106 is fixedly mounted on the opposite side of the two threaded seats 102. A connecting frame 107 is fixedly mounted on the end of the sliding rod 106 extending to the outside of the bearing platform 5. A limiting plate 108 is fixedly mounted on the connecting frame 107.

[0069] During specific implementation, the servo motor 103 can drive the synchronous pulley 104 to rotate. The synchronous pulley 104 drives the bidirectional lead screw 101 to rotate through the synchronous belt 105. The bidirectional lead screw 101 drives the threaded seat 102 threadedly connected thereto to move horizontally. The threaded seat 102 drives the sliding rod 106 to move. The sliding rod 106 drives the connecting frame 107 and the limiting plate 108 to move. The sponge pad can be clamped and fixed by the cooperation of the two limiting plates 108.

[0070] In addition, in order to ensure that the sliding rod 106 can slide on the bearing platform 5, through holes are formed in the side wall of the bearing platform 5. The sliding rod 106 passes through the through holes and extends to the outside of the bearing platform 5. The outer diameter of the sliding rod 106 is smaller than the inner diameter of the through holes.

[0071] The positioning assembly 10 further includes small gears 109 fixedly installed at both ends of the bidirectional lead screw 101. A large gear 110 meshingly connected with the small gears 109 is rotatably installed on the side wall of the bearing platform 5. A transmission gear 111 is coaxially connected to the front side of the large gear 110. Transmission racks 112 are meshingly connected to both the upper and lower parts of the transmission gear 111. Side plates 113 are slidably arranged at the four corners of the top surface of the bearing platform 5. The transmission racks 112 are fixedly connected to the side plates 113.

[0072] During specific implementation, the rotation of the bidirectional lead screw 101 can drive the small gears 109 to rotate. The small gears 109 drive the large gears 110 threadedly connected thereto to rotate. The large gears 110 drive the coaxially arranged transmission gears 111 to rotate. The transmission gears 111 drive the transmission racks 112 meshingly connected thereto to move horizontally. The transmission racks 112 drive the side plates 113 to further clamp and fix the sponge pad. The sponge pad can be adjusted according to its size from multiple directions, and then the sponge pad on the bearing platform 5 is positioned, so that the positioning effect of the sponge pad is better and it is not easy to shift, adapting to fixing sponge pads of various sizes.

[0073] Working principle: First, place the rubber composite layer 3 on the hot pressing device, then sequentially place the nano sponge core layer 2 and the flame retardant cloth composite layer 1 on the rubber composite layer 3, and align the edges of the flame retardant cloth composite layer 1 and the rubber composite layer 3. The servo motor 103 can drive the synchronous wheel 104 to rotate. The synchronous wheel 104 drives the bidirectional lead screw 101 to rotate through the synchronous belt 105. The bidirectional lead screw 101 drives the threaded seat 102 threadedly connected thereto to move horizontally. The threaded seat 102 drives the sliding rod 106 to move. The sliding rod 106 drives the connecting frame 107 and the limiting plate 108 to move. By rotating the bidirectional lead screw 101, the small gear 109 can be driven to rotate. The small gear 109 drives the large gear 110 threadedly connected thereto to rotate. The large gear 110 drives the transmission gear 111 coaxially arranged to rotate. The transmission gear 111 drives the transmission rack 112 engaged therewith to move horizontally. The transmission rack 112 drives the side plate 113 to further clamp and fix the sponge pad. It can be adjusted from multiple directions according to the size of the sponge pad. Then, position the sponge pad on the bearing table 5, so that the positioning effect of the sponge pad is better and it is not easy to shift, adapting to fixing sponge pads of various sizes. The sponge pad can be clamped and fixed by the cooperation of the two limiting plates 108. The external oil supply component can convey hydraulic oil into the interior of the pressure application oil cylinder 8, so that the pressure application oil cylinder 8 can push the hot pressing component 9 to move downward. The hot pressing plate 905 can be heated by the high-temperature electric heating tube 903 and the high-temperature heating plate 904. After the hot pressing plate 905 is heated, it can heat the rubber composite layer 3, the nano sponge core layer 2 and the flame retardant cloth composite layer 1, thereby achieving the effect of high-temperature hot pressing. The edges of the flame retardant cloth composite layer 1 and the rubber composite layer 3 are pressed by the hot pressing device, so that the edges of the flame retardant cloth composite layer 1 and the rubber composite layer 3 are melted and integrated, and the finished product of the flame retardant sponge pad is obtained.

[0074] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flame-retardant sponge pad, characterized in that, It includes a flame-retardant fabric composite layer (1), a nano sponge core layer (2) and a rubber composite layer (3), and the flame-retardant fabric composite layer (1), the nano sponge core layer (2) and the rubber composite layer (3) are arranged in sequence from top to bottom; The flame-retardant fabric composite layer (1) comprises raw materials in the following parts by weight: one part of flame-retardant fabric, 20 - 40 parts of natural rubber, 5 - 10 parts of stearic acid, 15 - 30 parts of tetrapropyl fluoride rubber, 10 - 15 parts of nitrile rubber, 1 - 3 parts of sulfur powder, 2 - 4 parts of anti-scorching agent; The nano sponge core layer (2) comprises raw materials in the following parts by weight: 30 - 60 parts of polyvinyl alcohol, 10 - 20 parts of sodium dodecyl sulfate, 3 - 6 parts of silicon dioxide, 2 - 4 parts of dextran, 4 - 8 parts of flame retardant, 2.5 - 5 parts of heat-resistant toughening agent; The rubber composite layer (3) comprises raw materials in the following parts by weight: 15 - 35 parts of cis-butadiene rubber, 4 - 12 parts of natural rubber, 4 - 12 parts of solution-polymerized styrene-butadiene rubber, 1.5 - 2 parts of elastic modifier.

2. A preparation method of the flame-retardant sponge pad as described in claim 1, characterized in that, It includes the following steps: S1. Prepare the flame-retardant fabric composite layer (1): Stir natural rubber, stearic acid, tetrapropyl fluoride rubber and nitrile rubber evenly, then add water to dilute to a concentration of 10% - 25% to form a mixed solution. Slowly add sulfur powder to the mixed solution, stir evenly to form a diluted solution; Then add the anti-scorching agent to the diluted solution, control the stirring speed at 500 - 800 r / min, and stir for 20 min to obtain a slurry; Introduce the obtained slurry onto the flame-retardant fabric, and form a slurry layer with a thickness of 0.4 - 0.8 mm on the surface of the flame-retardant fabric to obtain a flame-retardant fabric composite blank; Coating the slurry on the flame-retardant fabric composite blank by continuous knife coating method to form a flame-retardant fabric composite layer (1) with a thickness of 1.5 - 2.0 mm; S2. Prepare the nano sponge core layer (2): Add polyvinyl alcohol to deionized water, stir evenly, add sodium dodecyl sulfate to dissolve, and prepare a uniform dispersion solution; Add silicon dioxide to the dispersion solution, and perform ultrasonic treatment for 10 min to make it evenly dispersed in the dispersion solution; Add dextran, flame retardant and heat-resistant toughening agent to the dispersion solution, stir evenly, and place it in a constant temperature oscillator for a constant temperature oscillation curing process, with a constant temperature of 40°C and oscillation for 3 h; Pour the crosslinked and cured dispersion solution into a mold, place it in a vacuum chamber to exhaust for 15 min, and finally dry it in an oven at 50°C to obtain the nano sponge core layer (2); S3. Prepare the rubber composite layer (3): Add cis-butadiene rubber, natural rubber and solution-polymerized styrene-butadiene rubber to a fusion machine for fusion treatment to obtain a heat-conducting composition; Add the above heat-conducting composition and elastic modifier to the matrix, stir evenly in a stirring device, and then obtain the rubber composite layer (3) after calendering and vulcanization by a calender; S4. Cutting: Cut the flame-retardant fabric composite layer (1) and the rubber composite layer (3) into block structures with the same shape as the nano sponge core layer (2) and with both length and width greater than the nano sponge core layer (2) by 1.5 mm; S5. Forming: Place the rubber composite layer (3) on a hot pressing device, then sequentially place the nano sponge core layer (2) and the flame retardant cloth composite layer (1) on the rubber composite layer (3), and align the edges of the flame retardant cloth composite layer (1) and the rubber composite layer (3). Use the hot pressing device to press the edges of the flame retardant cloth composite layer (1) and the rubber composite layer (3) so that the edges of the flame retardant cloth composite layer (1) and the rubber composite layer (3) are melted and integrated to obtain the finished flame retardant sponge pad.

3. The preparation method of a flame-retardant sponge pad according to claim 2, wherein, In step S5, the hot pressing device for forming the flame retardant sponge pad includes a forming table (4), a bearing table (5), a support rod (6), a top plate (7), a pressing oil cylinder (8) and a hot pressing assembly (9). The bearing table (5) is slidably arranged on the top of the forming table (4). The support rod (6) is fixedly installed on the top surface of the forming table (4). The top plate (7) is fixedly installed at the top end of the support rod (6). The pressing oil cylinder (8) is fixedly installed on the top surface of the top plate (7). The hot pressing assembly (9) is slidably arranged on the support rod (6). The telescopic end of the pressing oil cylinder (8) is fixedly connected to the center of the top surface of the hot pressing assembly (9). The hot pressing assembly (9) includes a movable plate (901) slidably arranged on the support rod (6). A high-temperature heat insulation frame plate (902) is fixedly installed on the bottom surface of the movable plate (901). A high-temperature electric heating tube (903) is arranged inside the high-temperature heat insulation frame plate (902). A high-temperature heating plate (904) is also fixedly installed on the high-temperature heat insulation frame plate (902). A heat sealing plate (905) is fixedly installed on the outer surface of the high-temperature heating plate (904).

4. The preparation method of a flame-retardant sponge pad according to claim 3, characterized in that, The high-temperature electric heating tube (903) is arranged in a serpentine distribution inside the high-temperature heat insulation frame plate (902). The material of the high-temperature electric heating tube (903) is copper. A temperature sensor (906) is fixedly installed on the side wall of the high-temperature heat insulation frame plate (902). There is a gap between the temperature sensor (906) and the high-temperature electric heating tube (903).

5. The preparation method of a flame-retardant sponge pad according to claim 3, characterized in that, A movable groove (501) is formed on the top surface of the forming table (4). A driving screw (502) is rotatably installed inside the movable groove (501). A driving block (504) is threadedly connected to the driving screw (502). The top surface of the driving block (504) is fixedly connected to the center of the bottom surface of the bearing table (5). A driving motor (503) is fixedly installed on the side wall of the forming table (4). The driving end of the driving motor (503) is fixedly connected to one end of the driving screw (502).

6. The preparation method of a flame-retardant sponge pad according to claim 5, characterized in that, Guide grooves are symmetrically arranged on the top surface of the forming table (4). The guide grooves are distributed on both sides of the movable groove (501). Guide blocks are slidably arranged inside the guide grooves. The guide blocks are fixedly connected to the bottom surface of the bearing table (5).

7. The preparation method of a flame-retardant sponge pad according to claim 3, characterized in that, The supporting platform (5) is provided with a positioning assembly (10) for fixing the sponge during the sponge pad forming process, the positioning assembly (10) includes a bidirectional screw (101) rotatably mounted inside the supporting platform (5), a threaded seat (102) is threadedly connected to the bidirectional screw (101), a servo motor (103) is fixedly mounted inside the supporting platform (5), a synchronous wheel (104) is fixedly mounted on the driving end of the servo motor (103) and the middle outer wall of the bidirectional screw (101), a synchronous belt (105) is connected between the two synchronous wheels (104), a sliding rod (106) is fixedly mounted on the opposite side of the two threaded seats (102), and a connecting frame (107) is fixedly mounted on one end of the sliding rod (106) extending to the outside of the supporting platform (5), and a limiting plate (108) is fixedly mounted on the connecting frame (107).

8. The preparation method of a flame-retardant sponge pad according to claim 7, characterized in that, A through hole is provided on the side wall of the supporting platform (5), and the sliding rod (106) extends through the through hole to the outside of the supporting platform (5), and the outer diameter of the sliding rod (106) is smaller than the inner diameter of the through hole.

9. The preparation method of a flame-retardant sponge pad according to claim 7, wherein, The positioning assembly (10) further includes a small gear (109) fixedly mounted on both ends of the bidirectional screw rod (101); a large gear (110) meshingly connected to the small gear (109) is rotatably mounted on the side wall of the support platform (5); a transmission gear (111) is coaxially connected to the front side of the large gear (110); the upper and lower parts of the transmission gear (111) are meshingly connected to a transmission rack (112); side panels (113) are slidably provided at the four corners of the top surface of the support platform (5); and the transmission rack (112) is fixedly connected to the side panels (113).

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