A vehicle buoyancy-aiding and drag-reducing inflatable film material and its manufacturing method

Abstract

The present invention provides a vehicle buoyancy-aiding and drag-reducing inflatable film material and a manufacturing method thereof. The inflatable film material adopts a three-layer composite structure and is composed of an outer abrasion-resistant layer, an intermediate reinforcing layer, and an inner contact layer. Among them, the outer abrasion-resistant layer is made of cis-butadiene rubber, the intermediate reinforcing layer is formed by braiding and winding high-strength carbon fiber strands, the inner contact layer is made of nitrile rubber, and epoxy resin is used for bonding between the intermediate reinforcing layer and the outer abrasion-resistant layer and the inner contact layer. The above-mentioned inflatable film material is prepared by the soft-core method. The present invention can greatly improve the bursting strength of the film material and solve the technical problem of the failure of the inflatable film structure caused by the wave impact load approaching the inflation pressure of the inflatable film material under high-speed and high-sea conditions. It can also maintain the characteristic of low linear density of the film material, effectively cope with the high-speed and high-sea environment, provide material guarantee for realizing the hydrodynamic modification of the vehicle body by replacing the rigid deformation of traditional metal materials with the flexible deformation of inflatable film materials, save power energy, and relieve the pressure of logistics support.

Description

Technical Field

[0001] The present invention belongs to the technical field of inflatable equipment, and particularly relates to an inflatable film material for vehicle buoyancy assistance and drag reduction and a manufacturing method thereof. Background Art

[0002] At present, the main equipment capable of autonomous sea crossing and rapid river crossing is amphibious vehicles. Amphibious vehicles take into account the technical requirements of land use and sea crossing. However, due to the walking mechanism and overall layout requirements for land use, it is very difficult to design their shapes into streamline forms. Therefore, during the sea crossing process, it is necessary to first overcome a large form drag before it is possible to significantly increase the sailing speed. Generally, the hulls of displacement ships are in streamline forms, and the length-width ratios are generally above 5, while the length-width ratios of amphibious vehicles are generally below 3, and the vehicle bodies are square-shaped, which is completely different from displacement ships where the resistance during high-speed sailing is mainly wave-making resistance. The water speed of displacement amphibious vehicles can generally only reach 12 - 13 km / h. Unless the underwater part of the shape is significantly changed, it is extremely difficult for amphibious vehicles to achieve high speeds. Even for the EFV amphibious fighting vehicle applying hydroplane technology, its sailing speed is significantly slower compared to speedboats with similar weights and engine powers. Currently, amphibious vehicles at home and abroad still use the method of increasing the engine power to increase the water speed. However, since the power of amphibious vehicles during water travel is proportional to the cube of the speed, and the resistance is proportional to the square of the speed, the volume and weight of the engine and transmission device successively approach the inflection point as the vehicle speed increases, and continuing to increase the power will encounter a "vicious cycle". Therefore, increasing the water speed by improving the power pack has reached the technical limit.

[0003] As a new type of lightweight material, the inflatable film has multiple advantages. Generally, other components or loads are used to stretch the flexible film material to form a stable spatial surface to bear the loads acting on the surface. The inflatable film generally uses a film with excellent performance as the material. Through the air pressure difference formed inside and outside the film, the film surface is in a taut state, forming a structural form with a certain stiffness and shape, so as to resist the loads applied by the outside. The inflatable film structure has the characteristics of low density, small folding volume, low usage cost, reusability, and rapid deployment, including various forms such as air-supported, air-ribbed, air-cushioned, and airbag types, and has been widely used in occasions requiring large spans.

[0004] At present, the inflatable membrane materials used in vehicles traveling on the sea are mainly PVC composite membrane materials. PVC materials have the characteristics of light weight, heat insulation, heat preservation, moisture proof, flame retardancy, and simple construction. Due to the relatively low cost of the materials and the relatively simple forming technology, they are widely used in the manufacture of inflatable boats. However, the wave resistance of PVC materials is relatively poor. When the airbag travels on the sea, due to the undulating waves on the sea surface and the influence of the Karman vortex street phenomenon on the water intake part of the vehicle body, a dynamically changing load excitation will be generated on the impact surface of the airbag. This excitation is affected by the sea conditions and the moving speed of the hull, and its value and period will both change. According to the simulation results, under the conditions of sea state 4 and a speed of 40 kilometers per hour, the mean load fluctuation on the main impact surface of the airbag is such that the wave load is about 0.2 MPa, which is similar to the test results of the actual ship in the water tank.

[0005] However, since the current PVC membrane materials usually have an inflation pressure of about 0.2 MPa, which is close to the wave load, in the case of a large external load, the inflatable membrane structure is prone to a series of deformations, which will then lead to the tearing of the membrane material or the loss of bearing capacity, resulting in structural failure. Therefore, in order to avoid the possible structural failure problem caused by wave slapping, it is necessary to study new functional materials. Summary of the Invention

[0006] (I) Technical Problems to be Solved

[0007] The present invention provides a vehicle buoyancy-aiding and drag-reducing inflatable membrane material and its manufacturing method to solve the technical problem that the wave slapping load is close to the inflation pressure of the inflatable membrane material under high speed and high sea conditions, resulting in the failure of the inflatable membrane structure.

[0008] (II) Technical Solutions

[0009] To solve the above technical problems, the present invention provides a vehicle buoyancy-aiding and drag-reducing inflatable membrane material. This inflatable membrane material adopts a three-layer composite structure, which is composed of an outer anti-abrasion layer, an intermediate strengthening layer, and an inner contact layer. Among them, the outer anti-abrasion layer is made of cis-butadiene rubber, the intermediate strengthening layer is formed by braiding and winding high-strength carbon fibers in strands, the inner contact layer is made of nitrile rubber, and the intermediate strengthening layer is bonded to the outer anti-abrasion layer and the inner contact layer with epoxy resin.

[0010] Furthermore, the outer anti-abrasion layer, the intermediate strengthening layer, and the inner contact layer have the same thickness.

[0011] Furthermore, the carbon fiber selected is T1000GB-12K fiber.

[0012] In addition, the present invention also provides a vehicle buoyancy-aiding and drag-reducing airbag, which is manufactured using the above inflatable membrane material.

[0013] In addition, the present invention also provides a manufacturing method for a vehicle buoyancy-aiding and drag-reducing inflatable membrane material. This manufacturing method includes the following steps:

[0014] S1. Bake and soften the large-sized NBR raw rubber at 50-60 °C for 24 hours, then crush it and cut it into small-sized rubber blocks.

[0015] S2. Adjust the distance between the plasticating rolls to 2-3 mm, carry out raw rubber plasticating. After plasticating for 15 minutes, let it stand for 4 hours, and then carry out the next plasticating until the Williams plasticity requirement of 0.50 is achieved.

[0016] S3. Mix 15 parts of 35% acrylonitrile, 15 parts of polytetrafluoroethylene, and 15 parts of plasticizer TP-95 to form compounding agents. Put the compounding agents and the crushed rubber particles obtained by plasticating into a mixer and mix for 25 minutes to improve the dispersion of the compounding agents in the raw rubber.

[0017] S4. Pass the mixed colloid through the rolls of a two-roll mill again for hot refining. The opening of the rolls is 5 mm to increase the temperature of the rubber compound, improve the mixing dispersion, and increase the plasticity of the rubber compound.

[0018] S5. Carry out sulfonation treatment on the unvulcanized hot-refined rubber. Put the rubber compound and sulfur into a two-roll mill and plasticate for 10 minutes. The opening of the rolls is 5 mm, and the rolls are heated to 60 °C to obtain a sulfonated mixed rubber.

[0019] S6. Adjust the opening of the rolls to 2 mm and extrude the sulfonated mixed rubber into thin sheets.

[0020] S7. Pass the thin-sheet sulfonated mixed rubber through a rubber napping device to form pockmarks on the surface of the rubber cloth, and apply an intermediate layer bonding adhesive on the pockmarked surface.

[0021] S8. Wind the sulfonated mixed rubber coated with the bonding adhesive around the surface of a rigid cylinder and semi-vulcanize and shape it to form an NBR inner rubber layer.

[0022] S9. Strands of single carbon fibers are stranded to form a braided wire, and the carbon fibers are etched with an acidic solution to improve the surface friction performance of the carbon fibers.

[0023] S10. The stranded carbon fibers pass through the dipping tank of a winding machine, soak in the intermediate layer bonding adhesive, and are braided and wound on the surface of the NBR inner rubber layer to obtain an NBR composite carbon fiber braided mesh structure.

[0024] S11. Cut the cis-butadiene rubber into pieces, mix it with 15 parts of carbon black, and then carry out plasticating. The temperature of the rolls is controlled at 40-50 °C, the opening of the rolls is 5 mm, and stop plasticating when the plasticity of the rubber reaches 0.33 Williams.

[0025] S12. Add 1 part of softening agent, 1 part of butadiene monomer, and 1.5 parts of sulfur, and mix and knead the cis-butadiene rubber again. The temperature of the rolls is controlled at 40-60 °C.

[0026] S13. Adjust the distance between the pressure rollers to 2 mm and extrude into a thin sheet;

[0027] S14. Scour the thin sheet of cis-1,4-polybutadiene rubber and apply the intermediate layer bonding adhesive on the scoured surface;

[0028] S15. Wind the cis-1,4-polybutadiene rubber thin sheet applied with the intermediate layer bonding adhesive around the carbon fiber braided mesh structure and semi-vulcanize and shape it to obtain the cis-1,4-polybutadiene rubber outer rubber layer;

[0029] S16. Wind a wet nylon tape water-proof cloth around the overall rubber layer and send it into the vulcanization chamber with a vulcanization pressure of 15 MPa; utilize the shrinkage property of the wet nylon water-proof cloth to provide the bonding pressure and make the intermediate layer bonding adhesive firm;

[0030] S17. After vulcanization is completed, remove the water-proof cloth;

[0031] S18. Inject water into the gap between the rigid cylinder and the winding and remove the steel core;

[0032] S19. Apply a release agent after removal and obtain a three-layer composite vehicle buoyancy-aiding and drag-reducing inflatable film material after standing for 48 h.

[0033] (III) Beneficial effects

[0034] The present invention provides a vehicle buoyancy-aiding and drag-reducing inflatable film material and a manufacturing method thereof. The inflatable film material adopts a three-layer composite structure and is composed of an outer wear-resistant layer, an intermediate reinforcing layer and an inner contact layer; wherein, the outer wear-resistant layer is made of cis-1,4-polybutadiene rubber, the intermediate reinforcing layer is formed by braiding and winding high-strength carbon fibers in strands, the inner contact layer is made of nitrile rubber, and epoxy resin is used for bonding between the intermediate reinforcing layer and the outer wear-resistant layer and the inner contact layer. The above inflatable film material is prepared by the soft core method. The present invention can greatly improve the burst strength of the film material and solve the technical problem of the failure of the inflatable film structure caused by the wave impact load being close to the inflation pressure of the inflatable film material under high speed and high sea conditions; it can simultaneously maintain the characteristic of low linear density of the film material, effectively cope with the high speed and high sea condition environment, provide material guarantee for realizing the hydrodynamic modification of the vehicle body by replacing the rigid deformation of the traditional metal material with the flexible deformation of the inflatable film material, facilitate tasks such as flood fighting and river crossing transportation, increase the ship speed, improve the survivability, save power energy and relieve the pressure of logistics support. Description of the drawings

[0035] Figure 1 It is a schematic structural diagram of the vehicle buoyancy-aiding and drag-reducing inflatable film material according to the embodiment of the present invention;

[0036] Figure 2 It is a flowchart of the preparation of the inflatable film material in the embodiment of the present invention. Detailed implementation manners

[0037] To make the objectives, content, and advantages of the present invention clearer, the following further describes in detail the specific implementation manners of the present invention with reference to the accompanying drawings and embodiments.

[0038] This embodiment provides a vehicle floating and drag-reducing inflatable film material, whose structure is as Figure 1 shown, adopting a three-layer composite structure, which is composed of an outer wear-resistant layer 1, an intermediate reinforcing layer 2, and an inner contact layer 3. The outer wear-resistant layer 1, the intermediate reinforcing layer 2, and the inner contact layer 3 have the same thickness.

[0039] The outer wear-resistant layer 1 is made of cis-butadiene rubber. Cis-butadiene rubber is a cis-structured rubber polymerized from butadiene. It has the characteristics of excellent elasticity and wear resistance, good aging resistance, excellent low-temperature resistance, small heat generation under dynamic load, and is easy to bond with metal. The usage range is -60 to +100 °C.

[0040] The intermediate reinforcing layer 2 is formed by braiding and winding high-strength carbon fibers in strands, and epoxy resin is selected as the bonding adhesive to bond with the outer wear-resistant layer 1 and the inner contact layer 3. The carbon fibers are etched with acidic solutions such as sulfuric acid to increase the surface roughness and surface wettability, and strengthen the bonding strength between the carbon fibers and the inner and outer rubber layers. The carbon fiber material has anisotropic characteristics. After the carbon fibers are etched, two-dimensional braiding of the carbon fibers can improve the tensile strength, impact resistance, shear strength, toughness, and collision energy absorption potential of the carbon fiber braided net, and overall improve the performance of the inflatable film structure in terms of impact resistance, shear strength, toughness, collision energy absorption, and stiffness. In this embodiment, the carbon fiber selected is T1000GB-12K fiber, whose tensile strength is 6370 MPa, elastic modulus is 30 ton / mm 3 , the single-strand fiber diameter is 0.76 mm, the elongation at break is 2.2%, and the theoretical maximum breaking strength of a single fiber is 2889 N.

[0041] The inner contact layer 3 is made of nitrile rubber. Nitrile rubber is a copolymer of butadiene and acrylonitrile, and it has good heat resistance, airtightness, wear resistance, water resistance, etc., and strong bonding force.

[0042] The above inflatable film material is prepared by the soft core method, and the overall process flow is as Figure 2 shown, specifically including the following steps:

[0043] S1. Bake and soften the large-sized nitrile rubber raw rubber at a temperature of 50 - 60 °C for 24 hours, then crush it and cut it into small rubber blocks of 10 Kg.

[0044] S2. Adjust the spacing of the plasticating rollers to 2 - 3 mm, carry out plasticating of the raw rubber. After plasticating for 15 min, let it stand for 4 h, and then carry out the next plasticating until the plasticity requirement of 0.50 (Williams) is reached.

[0045] S3. Mix 15 parts of 35% acrylonitrile, 15 parts of polytetrafluoroethylene, and 15 parts of plasticizer TP-95 to form a compounding agent. Put the compounding agent and the broken rubber pellets obtained from plastic refining into a mixer and mix for 25 minutes to improve the dispersion of the compounding agent in the raw rubber;

[0046] S4. Reheat the mixed colloid through the calender rolls of a two-roll mill. The opening of the calender rolls is 5 mm to increase the temperature of the rubber compound, improve the mixing dispersion, and increase the plasticity of the rubber compound;

[0047] S5. Sulfurize the unvulcanized reheated rubber. Put the rubber compound and sulfur into a two-roll mill and plasticize for 10 minutes. The opening of the calender rolls is 5 mm, and the calender rolls are heated to 60 °C to obtain a sulfurized mixed rubber;

[0048] S6. Adjust the opening of the calender rolls to 2 mm and extrude the sulfurized mixed rubber into a thin sheet;

[0049] S7. Pass the thin sulfurized mixed rubber sheet through a rubber napping device to form dimples on the surface of the rubber cloth, and apply an intermediate layer bonding rubber on the dimpled surface;

[0050] S8. Wind the sulfurized mixed rubber with the applied bonding rubber around the surface of a rigid cylinder and semi-vulcanize and shape it to form a nitrile rubber inner rubber layer;

[0051] S9. Stranding single carbon fibers to form a braided wire, and etching the carbon fibers with an acidic solution such as sulfuric acid to improve the surface friction performance of the carbon fibers;

[0052] S10. The stranded carbon fibers pass through the dipping tank of a winding machine, soak in the intermediate layer bonding rubber, and are braided and wound on the surface of the nitrile rubber inner rubber layer to obtain a nitrile rubber composite carbon fiber braided mesh structure;

[0053] S11. Cut and mix 15 parts of carbon black into cis-butadiene rubber and then plasticize it. The temperature of the calender rolls is controlled at 40 - 50 °C, the opening of the calender rolls is 5 mm, and stop plasticizing when the plasticity of the rubber reaches 0.33 Williams;

[0054] S12. Add 1 part of softening agent, 1 part of butadiene monomer, and 1.5 parts of sulfur, and remix and mix the cis-butadiene rubber. The temperature of the calender rolls is controlled at 40 - 60 °C;

[0055] S13. Adjust the distance between the calender rolls to 2 mm and extrude it into a thin sheet;

[0056] S14. Nap the thin cis-butadiene rubber sheet and apply an intermediate layer bonding rubber on the dimpled surface;

[0057] S15. Wind the cis-butadiene rubber sheet with the applied intermediate layer bonding rubber around the carbon fiber braided mesh structure and semi-vulcanize and shape it to obtain a cis-butadiene rubber outer rubber layer;

[0058] S16. Wind a wet nylon tape water-proof cloth outside the overall rubber layer and send it into the vulcanization chamber with a vulcanization pressure of 15 MPa; utilize the shrinkage characteristics of the wet nylon water-proof cloth to provide an adhesive pressure to stabilize the adhesive of the intermediate layer.

[0059] S17. After vulcanization is completed, remove the water-proof cloth.

[0060] S18. Inject water into the gap between the rigid cylinder and the winding to remove the steel core.

[0061] S19. Apply a release agent after removal and let it stand for 48 h to obtain a three-layer composite vehicle drag reduction film material.

[0062] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A manufacturing method of a vehicle buoyancy-aiding and drag-reducing inflatable film material, characterized in that The manufacturing method comprises the following steps: S1. The large piece of nitrile rubber raw rubber is baked at 50 to 60 ° C for 24 hours to soften the rubber and then broken into small pieces; S2. Adjust the spacing between the plasticizing rollers to 2 to 3 mm, plasticize the raw rubber, and stop for 4 hours after plasticizing for 15 minutes before plasticizing again until the plasticity requirement of 0.50 is reached; S3 mixed 35% acrylonitrile 15 parts, polytetrafluoroethylene 15 parts, plasticizer TP-9515 parts, to form a compounding agent, the compounding agent and the plasticized crushed rubber particles together into a mixer, mixing 25min, improve the dispersibility of the compounding agent in the raw rubber; S4. The mixed colloid is again heat-refined through the open mill roller, the roller opening is 5mm, the temperature of the rubber is increased, the mixing dispersibility is improved, and the plasticity of the rubber is improved; S5. The uncured hot-mixed rubber was sulfonated, the rubber and sulfur were put into the open mill for plastication for 10 min, the roller opening was 5 mm, the roller was heated to 60 ° C, and the sulfonated rubber was obtained; S6. Adjust the roller opening to 2 mm and extrude the sulfonated rubber mixture into a sheet; S7. The flaky sulfonated rubber compound is passed through a rubber beating device to form pits on the surface of the rubber cloth, and an intermediate layer of adhesive is applied on the pitted surface; S8. The mixed rubber after applying the adhesive and adding sulfur is wound on the surface of the rigid cylinder, semi-vulcanized and shaped to form an inner layer of nitrile rubber; S9. Plying single carbon fibers to form a braided wire, etching the carbon fibers with an acid solution to improve the friction performance of the carbon fiber surface; S10. The stranded carbon fiber is passed through a winding machine dipping tank, impregnated with an intermediate layer of adhesive, and woven and wound on the surface of the inner rubber layer of nitrile rubber to obtain a nitrile rubber composite carbon fiber woven mesh structure; S11. The butadiene rubber was cut into pieces and mixed with 15 parts of carbon black for plasticization. The roller temperature was controlled at 40 to 50 ° C, the roller opening was 5 mm, and the mixing reached a rubber plasticity of 0.33 Vickers, and the plasticization was stopped; S12. Add 1 part of softener, 1 part of butadiene monomer, 1.5 parts of sulfur, mix the butadiene rubber again for mixing, and control the roller temperature at 40 to 60 ° C; S13. Adjust the roller spacing to 2 mm and extrude into a thin sheet; S14. Treat the thin sheet of butyl rubber with hemp, and apply an intermediate layer of adhesive on the hemp surface; S15. The butyl rubber sheet coated with the intermediate layer of adhesive is wound on the carbon fiber woven mesh structure, semi-vulcanized and shaped to obtain a butyl rubber outer layer; S16. Wrap wet nylon tape around the entire rubber layer and send it into the vulcanization chamber at a vulcanization pressure of 15 MPa; utilize the shrinkage characteristics of the wet nylon tape to provide bonding pressure to stabilize the adhesive of the middle layer; S17. After vulcanization is completed, remove the water adhesive tape; S18. Inject water into the gap between the rigid cylinder and the winding to remove the steel core; S19. After detachment, a release agent is applied, and after parking for 48 hours, a three-layer composite vehicle buoyancy-aiding and drag-reducing inflatable membrane material is obtained.

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