Flame-retardant rubber hose for automobiles and method for producing the same

Abstract

The application discloses a kind of automobile fire-retardant rubber hoses and preparation method thereof, it is related to automobile fire-retardant rubber hose preparation technical field, it is composed of inner rubber layer, middle reinforcing layer and outer rubber layer, the inner rubber layer, outer rubber layer all include: ethylene-propylene-diene rubber, aluminium hydroxide, aluminium hypophosphite, melamine cyanurate, zinc borate, white carbon black, carbon black, modified graphene, dicumyl peroxide, accelerator CZ, zinc oxide, stearic acid, silane coupling agent, antioxidant RD, plasticizer, lubricant, using inner rubber layer, outer rubber layer uses the ethylene-propylene-diene rubber of limited weight part as matrix, compound aluminium hydroxide, aluminium hypophosphite, melamine cyanurate and zinc borate constitute halogen-free composite fire-retardant system, with modified graphene synergistic flame retardant, off-fire self-extinguishing, low smoke halogen-free, not easy to ignite spread under the high temperature complex working condition of automobile engine compartment, significantly improve the safety performance of vehicle pipeline use.

Description

Technical Field

[0001] This invention relates to the field of automotive flame-retardant rubber hose manufacturing technology, specifically to an automotive flame-retardant rubber hose and its manufacturing method. Background Technology

[0002] As the automotive industry develops towards higher power, compactness, and longer service life, the interior space of the car engine compartment is compact and the operating temperature is high. The pipeline area is easily exposed to high-temperature heat sources, electrical sparks, and oil media, which puts forward higher requirements for the flame retardancy, high and low temperature resistance, pressure resistance, and aging resistance of rubber hoses.

[0003] Currently, traditional automotive rubber hoses mostly use ordinary rubber as a single matrix, and halogenated flame retardants are often used for flame retardancy. These hoses not only produce a large amount of smoke and are toxic and harmful when burning, resulting in poor environmental performance, but also have a low flame retardancy rating. They are prone to continuous combustion and rapid flame spread when exposed to open flames, posing significant safety hazards. At the same time, the reinforcement effect of traditional hose formulations is generally poor, and their ozone resistance and aging resistance are insufficient. Under long-term operating conditions with alternating temperatures of -40℃ to 120℃, they are prone to hardening, cracking, bulging, and leakage.

[0004] In addition, most existing conventional rubber hoses have a simple double-layer structure and lack a high-strength braided reinforcement layer design, resulting in low overall pressure resistance, which makes it difficult to meet the requirements of high-pressure cooling, vacuum, and fluid transportation in automobiles. Traditional manufacturing processes are crude in their mixing and feeding methods and have unreasonable temperature control, which easily leads to defects such as uneven dispersion of additives, scorching of rubber compounds, large dimensional deviations in finished products, and numerous appearance defects. Furthermore, the lack of dedicated extrusion conveying and impurity removal devices makes the rubber sheets prone to deviation during conveying and to trap impurities on the surface, further reducing the finished product qualification rate and service life of the rubber hoses. They can no longer meet the current automotive safety regulations and the durability requirements of the entire vehicle. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a flame-retardant rubber hose for automobiles and its preparation method, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a flame-retardant rubber hose for automobiles, comprising an inner rubber layer, an intermediate reinforcing layer, and an outer rubber layer, wherein the inner and outer rubber layers each comprise: ethylene propylene diene monomer (EPDM) rubber, aluminum hydroxide, aluminum hypophosphite, melamine cyanurate, zinc borate, silica, carbon black, modified graphene, dicumyl peroxide, accelerator CZ, zinc oxide, stearic acid, silane coupling agent, antioxidant RD, plasticizer, and lubricant.

[0007] A flame-retardant rubber hose for automobiles, wherein the inner and outer rubber layers are both made from the following raw materials in parts by weight: 100 parts EPDM rubber, 65 parts aluminum hydroxide, 35 parts aluminum hypophosphite, 20 parts melamine cyanurate, 10 parts zinc borate, 32 parts silica, 22 parts carbon black, 3 parts modified graphene, 2.2 parts dicumyl peroxide, 1.8 parts accelerator CZ, 5 parts zinc oxide, 2.5 parts stearic acid, 2.5 parts silane coupling agent, 2 parts antioxidant RD, 9 parts plasticizer, and 1.2 parts lubricant.

[0008] Preferably, the intermediate reinforcing layer is a polyester cord braided layer.

[0009] A method for preparing a flame-retardant rubber hose for automobiles, characterized by comprising the following steps: Step 1: Raw material pretreatment: Place EPDM rubber in an internal mixer and plasticize it for 8-12 minutes at 105-115℃ and 35-45r / min to obtain plasticized rubber; Step 2: Mixing: Add zinc oxide, stearic acid, antioxidant RD, and lubricant to the plasticized rubber obtained in Step 1 in sequence, and mix for 3-5 minutes; then add silica, carbon black, modified graphene, and silane coupling agent, heat to 120-130℃, and mix for 6-8 minutes; next, add aluminum hydroxide, aluminum hypophosphite, melamine cyanurate, zinc borate, and plasticizer, and mix for 4-6 minutes; finally, add dicumyl peroxide and accelerator CZ, cool to 85-95℃, mix for 2-3 minutes, and discharge to obtain the compounded rubber; Step 3: Inner rubber layer forming: The compound obtained in Step 2 is extruded through an extruder, and the extrusion temperature is controlled at 90-100℃ to obtain the inner rubber layer preform; Step 4: Reinforcing layer weaving: The polyester cords are woven onto the surface of the inner rubber layer blank on a weaving machine at a weaving density of 80-90 strands / inch to obtain a blank with a reinforcing layer; Step 5: Outer rubber layer forming: The compound obtained in Step 2 is extruded again through an extruder to coat the surface of the preform with the reinforcing layer obtained in Step 4. The extrusion temperature is controlled at 95-105℃ to obtain the hose preform. Step 6: Vulcanization molding: Place the hose blank obtained in step 5 into a vulcanization tank for vulcanization, and after cooling to room temperature, obtain the flame-retardant rubber hose for automobiles.

[0010] Preferably, step six, vulcanization molding, is carried out at 160-170℃ and 1.0-1.2MPa for 15-20 minutes.

[0011] Preferably, the extruder includes a body, an extrusion head is installed at the feed inlet of the body, and a conveying box is fixedly installed on the top of the extrusion head.

[0012] Preferably, a protective mechanism is installed at the front end of the conveyor box, a driving mechanism is installed on the outer side of the front end of the conveyor box, an upper limit mechanism is installed in the middle section of the conveyor box, a side adjustment mechanism is installed in the arc-shaped section of the conveyor box, a lower limit mechanism is installed at the tail end of the conveyor box, and a film is inserted inside the conveyor box.

[0013] This invention provides a flame-retardant rubber hose for automobiles and its preparation method, which has the following beneficial effects: 1. The inner and outer rubber layers are made of EPDM rubber in a limited weight ratio as the matrix, and are compounded with aluminum hydroxide, aluminum hypophosphite, melamine cyanurate and zinc borate to form a halogen-free composite flame retardant system. Modified graphene is added for synergistic flame retardancy. It is self-extinguishing after the flame is removed, low smoke and halogen-free. It is not easy to ignite and spread under the high temperature and complex working conditions in the automotive engine compartment, which significantly improves the safety performance of the vehicle's pipeline.

[0014] 2. This invention uses a combination of silica and carbon black for reinforcement, along with a reasonable blend of silane coupling agent, antioxidant, plasticizer, and vulcanization system, to give the hose excellent resistance to high and low temperatures, ozone, aging, and mechanical properties. It is not prone to hardening, cracking, or leakage after long-term use. The addition of a polyester cord braided reinforcement layer in the middle provides advantages such as tight interlayer bonding, pressure resistance, explosion protection, and deformation resistance.

[0015] 3. This invention employs a preparation process involving segmented plasticizing, batch feeding with controlled temperature mixing, layer-by-layer extrusion coating, and constant temperature and pressure vulcanization. This ensures uniform dispersion of all raw material components, effectively preventing scorching of the rubber compound, resulting in high dimensional accuracy and good molding stability of the finished product. Combined with dedicated extrusion conveying equipment, it enables automatic limiting, guiding, and surface impurity removal of the rubber sheet, effectively reducing the defect rate of the finished product. The process is simple, easily scalable for mass production, and the formula is environmentally friendly with readily available raw materials, resulting in a high overall cost-effectiveness. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the extruder of the present invention; Figure 2 This is a schematic diagram of the conveyor box structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the conveyor box of the present invention; Figure 4 This is a schematic diagram of the internal structure of the drive box of the present invention; Figure 5 This is a schematic diagram of the rear view of the drive box structure of the present invention; Figure 6 This is a top view of the protective mechanism of the present invention; Figure 7 This is a schematic diagram of the position and structure of the lower scraper block in this invention; Figure 8 This is a schematic diagram of the internal structure of the guide rail of the present invention; Figure 9This is a schematic diagram of the worm gear structure of the present invention.

[0017] In the image: 1. Body; 2. Squeeze in the head; 3. Conveyor box; 4. Protective mechanism; 401. Collection box; 402. Upper scraper; 403. Side plate; 404. First side scraper; 405. Conveying channel; 406. Second side scraper; 407. Baffle; 408. Drawer; 409. Lower scraper; 5. Drive mechanism; 501. Drive box; 502. First electric telescopic rod; 503. First fixed frame; 504. First worm gear; 505. First worm wheel; 506. Upper roller; 507. Second worm gear; 508. Lower roller; 509. Second worm wheel; 510. First motor; 511. Hexagonal column; 512. First rope sensor; 6. Upper limit mechanism; 601. Second electric telescopic rod; 602. Second pull rope sensor; 603. Guide rod; 604. Mounting plate; 605. Mounting bracket; 606. First guide roller; 7. Side adjustment mechanism; 701. Guide rail; 702. Screw; 703. Second motor; 704. Third pull rope sensor; 705. Push column; 706. Second fixing frame; 707. Second guide roller; 8. Lower limit mechanism; 801. Third electric telescopic rod; 802. Fourth pull rope sensor; 803. Moving frame; 804. Third guide roller; 9. Film. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] Example 1 This invention provides a technical solution: a flame-retardant rubber hose for automobiles, comprising an inner rubber layer, a middle reinforcing layer, and an outer rubber layer. Both the inner and outer rubber layers include: ethylene propylene diene monomer (EPDM) rubber, aluminum hydroxide, aluminum hypophosphite, melamine cyanurate, zinc borate, silica, carbon black, modified graphene, dicumyl peroxide, accelerator CZ, zinc oxide, stearic acid, silane coupling agent, antioxidant RD, plasticizer, and lubricant.

[0020] Example 2 This invention provides a technical solution: a flame-retardant rubber hose for automobiles, wherein the inner and outer rubber layers are both prepared from the following raw materials in parts by weight: 100 parts EPDM rubber, 65 parts aluminum hydroxide, 35 parts aluminum hypophosphite, 20 parts melamine cyanurate, 10 parts zinc borate, 32 parts silica, 22 parts carbon black, 3 parts modified graphene, 2.2 parts dicumyl peroxide, 1.8 parts accelerator CZ, 5 parts zinc oxide, 2.5 parts stearic acid, 2.5 parts silane coupling agent, 2 parts antioxidant RD, 9 parts plasticizer, and 1.2 parts lubricant; the intermediate reinforcing layer is a polyester cord braided layer.

[0021] Example 3 Please see Figures 1 to 9 The extruder includes a body 1, an extrusion head 2 installed at the feed inlet of the body 1, a conveyor box 3 fixedly installed on the top of the extrusion head 2, a protective mechanism 4 installed at the front end of the conveyor box 3, a drive mechanism 5 installed on the outer side of the front end of the conveyor box 3, an upper limit mechanism 6 installed in the middle section of the conveyor box 3, a side adjustment mechanism 7 installed in the arc section of the conveyor box 3, a lower limit mechanism 8 installed at the tail end of the conveyor box 3, and a film 9 inserted inside the conveyor box 3.

[0022] The protective mechanism 4 includes a collection box 401, which is installed below the inlet of the conveyor box 3. The driving mechanism 5 includes a drive box 501, which is installed on the outer front end of the conveyor box 3. A first electric telescopic rod 502 is fixedly connected to the top of the drive box 501. The telescopic end of the first electric telescopic rod 502 extends into the drive box 501 and is fixedly connected to a first fixing frame 503. An upper roller 506 is rotatably connected to the inside of the first fixing frame 503 via bearings. A lower roller 508 is rotatably connected to the inside of the front end of the conveyor box 3 via bearings. Both ends of the lower roller 508 extend into the inside of the drive box 501. Both ends of the upper roller 506 pass through the first fixing frame 503 and extend into the inside of the drive box 501. A baffle 407 is fixedly connected to the front end of the first fixing frame 503, and the bottom end of the baffle 407 is inserted into the conveyor box 3. Inside, an upper scraper 402 is fixedly connected to the front end of the baffle 407, a first side scraper 404 is fixedly connected to the side of the upper scraper 402, a side plate 403 is fixedly connected to the other side of the upper scraper 402, a second side scraper 406 is fixedly connected to the front end of the side plate 403, a conveying channel 405 is fixedly connected to the bottom end of the side plate 403, a lower scraper 409 is fixedly connected to the inner wall of the collection box 401, a drawer 408 is inserted inside the collection box 401, and one end of the drawer 408 extends to the outside of the collection box 401.

[0023] The top of the drive box 501 is fixedly connected to a first pull rope sensor 512, and the pull rope end of the first pull rope sensor 512 is connected to the top of the first fixing frame 503.

[0024] The upper roller 506 has a first worm gear 505 fixedly sleeved on the outer side of one end, and the lower roller 508 has a second worm gear 509 fixedly sleeved on the outer side of one end. The bottom of the inner cavity of the drive box 501 is rotatably connected to the second worm 507 via a bearing. The bottom of the first fixed frame 503 is rotatably connected to the first worm 504 via a bearing. The top of the second worm 507 is fixedly connected to a hexagonal column 511, and the top of the hexagonal column 511 extends into the interior of the first worm 504. The first worm 504 is driven by the first worm gear 505, and the second worm 507 is driven by the second worm gear 509. The bottom of the drive box 501 is fixedly connected to the first motor 510, and the output end of the first motor 510 is connected to the bottom end of the second worm 507. The top of the conveyor box 3 is fixedly connected to the second pull rope sensor 602, and the pull rope end of the second pull rope sensor 602 is connected to the surface of the mounting plate 604.

[0025] The upper limit mechanism 6 includes a second electric telescopic rod 601. The top of the conveyor box 3 is fixedly connected to the second electric telescopic rod 601, and the telescopic end of the second electric telescopic rod 601 extends into the interior of the conveyor box 3 and is fixedly connected to a mounting plate 604. The bottom of the mounting plate 604 is fixedly connected to several mounting brackets 605. The mounting brackets 605 are rotatably connected to the first guide rollers 606 through bearings. The top of the mounting plate 604 and both sides of the second electric telescopic rod 601 are fixedly connected to guide rods 603. The top ends of the guide rods 603 extend to the top of the conveyor box 3.

[0026] The side adjustment mechanism 7 includes a guide rail 701, which is mounted on the surface of the conveyor box 3. The guide rail 701 is rotatably connected to a screw 702 through a bearing. The outer side of the screw 702 is threadedly connected to a push column 705. One end of the push column 705 extends into the conveyor box 3 and is fixedly connected to a second fixing frame 706. The second fixing frame 706 is rotatably connected to a second guide roller 707 through a bearing. The top of the guide rail 701 is fixedly connected to a second motor 703, and the output end of the second motor 703 is connected to the top end of the screw 702. The top end of the guide rail 701 is fixedly connected to a third pull rope sensor 704, and the pull rope end of the third pull rope sensor 704 is connected to the top end of the push column 705.

[0027] The lower limit mechanism 8 includes a third electric telescopic rod 801, which is installed on the side of the tail end of the conveyor box 3. The telescopic end of the third electric telescopic rod 801 extends into the interior of the conveyor box 3 and is fixedly connected to a movable frame 803. The interior of the movable frame 803 is rotatably connected to a third guide roller 804 via a bearing. A fourth pull rope sensor 802 is fixedly connected to the side of the conveyor box 3, and the pull rope end of the fourth pull rope sensor 802 is fixedly connected to the side of the movable frame 803.

[0028] In summary, the flame-retardant rubber hose for automobiles and its preparation method are described below. When in use, one end of the rubber sheet 9 is inserted into the inside of the conveying box 3 through the front opening of the conveying box 3, and the rubber sheet 9 is adapted by the upper limit mechanism 6 and the lower limit mechanism 8, as well as the side adjustment mechanism 7 and the drive mechanism 5. The second electric telescopic rod 601 drives the mounting plate 604, mounting frame 605, and first guide roller 606 to move up or down. The output end of the second motor 703 drives the screw 702 to rotate, so that the screw 702 drives the push column 705 to move the second fixed frame 706 and the second guide roller 707. The telescopic end of the third electric telescopic rod 801 drives the moving frame 803 and the third guide roller 804 to move, so that the outer sides of the third guide roller 804, the second guide roller 707, and the first guide roller 606 are in contact with the surface of the film 9. The telescopic end of the first electric telescopic rod 502 drives the first fixed frame 503 to move the upper roller 506 up or down, and the first fixed frame 503 drives the first worm gear 504 to move up, so that the first worm gear 504 moves up or down along the outer side of the hexagonal column 511 to clamp the film 9. The output of the first motor 510 drives the second worm 507 to rotate, which in turn drives the first worm 504 to rotate via the hexagonal column 511. The first worm 504 drives the first worm wheel 505 to rotate the upper roller 506. The second worm 507 drives the lower roller 508 to rotate via the second worm wheel 509. The upper roller 506 and the lower roller 508 drive the film 9 to enter the extrusion head 2 and the machine body 1 into the conveyor box 3. As the film 9 moves, the upper surface of the film 9 is cleaned by the upper scraper 402, and the debris is guided by the inclined side plate 403 through the upper scraper 402 and enters the conveying channel 405 through the side plate 403. The side of the film 9 is cleaned by the second side scraper 406 and the first side scraper 404, and the lower surface of the film 9 is cleaned by the lower scraper 409, so that the debris falls into the drawer 408.

[0029] All standard parts used in this application can be purchased from the market, and can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art. The installation methods between equipment are also the same as conventional installation methods in the prior art. For example, the two ends of shaft-shaped parts are connected by bearings, the connection position of valve components is provided with anti-leakage rubber strips, the outside of threaded rods or lead rods is provided with dust covers, and the equipment can be driven by either built-in batteries or external power supply. The control method is automatic control by a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art and is common knowledge in the field. Since this invention is mainly used to protect mechanical devices, this invention will not explain the control method and circuit connection in detail. The external controller mentioned in the specification can play a control role for the electrical components mentioned herein, and the external controller is a conventional known device.

[0030] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flame-retardant rubber hose for automobiles, characterized in that: It consists of an inner rubber layer, an intermediate reinforcing layer, and an outer rubber layer. The inner and outer rubber layers each include: ethylene propylene diene monomer (EPDM) rubber, aluminum hydroxide, aluminum hypophosphite, melamine cyanurate, zinc borate, silica, carbon black, modified graphene, dicumyl peroxide, accelerator CZ, zinc oxide, stearic acid, silane coupling agent, antioxidant RD, plasticizer, and lubricant.

2. A flame-retardant rubber hose for automobiles, characterized in that: Both the inner and outer rubber layers are prepared from the following raw materials in parts by weight: 100 parts EPDM rubber, 65 parts aluminum hydroxide, 35 parts aluminum hypophosphite, 20 parts melamine cyanurate, 10 parts zinc borate, 32 parts silica, 22 parts carbon black, 3 parts modified graphene, 2.2 parts dicumyl peroxide, 1.8 parts accelerator CZ, 5 parts zinc oxide, 2.5 parts stearic acid, 2.5 parts silane coupling agent, 2 parts antioxidant RD, 9 parts plasticizer, and 1.2 parts lubricant.

3. The flame-retardant rubber hose for automobiles and its preparation method according to claim 1, characterized in that: The intermediate reinforcing layer is a polyester cord braided layer.

4. A method for preparing a flame-retardant rubber hose for automobiles, characterized in that: Includes the following steps: Step 1: Raw material pretreatment: Place EPDM rubber in an internal mixer and plasticize it for 8-12 minutes at 105-115℃ and 35-45r / min to obtain plasticized rubber; Step 2: Mixing: Add zinc oxide, stearic acid, antioxidant RD, and lubricant to the plasticized rubber obtained in Step 1 in sequence, and mix for 3-5 minutes; then add silica, carbon black, modified graphene, and silane coupling agent, heat to 120-130℃, and mix for 6-8 minutes; next, add aluminum hydroxide, aluminum hypophosphite, melamine cyanurate, zinc borate, and plasticizer, and mix for 4-6 minutes; finally, add dicumyl peroxide and accelerator CZ, cool to 85-95℃, mix for 2-3 minutes, and discharge to obtain the compounded rubber; Step 3: Inner rubber layer forming: The compound obtained in Step 2 is extruded through an extruder, and the extrusion temperature is controlled at 90-100℃ to obtain the inner rubber layer preform; Step 4: Reinforcing layer weaving: The polyester cords are woven on the surface of the inner rubber layer blank on a weaving machine at a weaving density of 80-90 strands / inch to obtain a blank with a reinforcing layer; Step 5: Outer rubber layer forming: The compound obtained in Step 2 is extruded again through an extruder to coat the surface of the preform with reinforcing layer obtained in Step 4. The extrusion temperature is controlled at 95-105℃ to obtain the hose preform. Step 6: Vulcanization molding: Place the hose blank obtained in step 5 into a vulcanization tank for vulcanization, and after cooling to room temperature, obtain the flame-retardant rubber hose for automobiles.

5. The method for preparing a flame-retardant rubber hose for automobiles according to claim 1, characterized in that: Step six: Vulcanization molding. Vulcanize at 160-170℃ and 1.0-1.2MPa for 15-20 minutes.

6. The method for preparing a flame-retardant rubber hose for automobiles according to claim 1, characterized in that: The extruder includes a body (1), an extrusion head (2) is installed at the feed inlet of the body (1), and a conveying box (3) is fixedly installed on the top of the extrusion head (2).

7. The method for preparing a flame-retardant rubber hose for automobiles according to claim 1, characterized in that: The front end of the conveyor box (3) is equipped with a protective mechanism (4), the outer side of the front end of the conveyor box (3) is equipped with a driving mechanism (5), the middle section of the conveyor box (3) is equipped with an upper limit mechanism (6), the arc section of the conveyor box (3) is equipped with a side adjustment mechanism (7), the tail end of the conveyor box (3) is equipped with a lower limit mechanism (8), and a film (9) is inserted inside the conveyor box (3).

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