Low-profile, high-performance militaryComposites-Aramid fiber
Aramid fiber has the advantages of high strength, high modulus, high temperature resistance, light weight, etc., and is prepared from The resulting aramid paper and aramid honeycomb core material have broad application prospects and are indispensable key materials in the fields of national defense, aerospace, rail transportation, power and electrical, etc.
1. Product Overview
The full name of aramid fiber is “aromatic polyamide fiber”. It has ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, light weight, etc. With excellent performance, aramid fiber was successfully developed and commercialized by DuPont in the United States in the 1960s. Aramid fiber will not be directly used as a final product. It must at least be made into fabrics or corresponding composite materials before it can be used.
The type and performance of aramid fiber have a relatively large impact on the performance of the final product. Aramid fiber can be divided into three types: ortho-aramid, para-aramid (aramid 1414, PPTA) and meta-aramid (aramid 1313, PMTA). Among them, the products that have been industrialized mainly include meta-aramid and para-aramid. Two types of aramid. Aramid paper made of pure meta-aramid has high strength, low deformation, high temperature resistance, chemical corrosion resistance, flame retardancy and excellent electrical insulation properties. It is widely used in fields such as national defense, aerospace, high-speed trains and electrical insulation. Para-aramid has better overall properties than meta-aramid and can be used in the aerospace industry to manufacture solid rocket motor casings for missiles and secondary structural materials for large aircraft (such as cabin doors and windows). , wing-related parts, etc.), body armor, bulletproof helmets, stab-proof and cut-proof suits, explosive disposal suits, high-elasticity parachutes, bullet-proof car bodies, armor plates, etc. in the national defense industry.
From aramid fiber to aramid honeycomb core material, it needs to go through a series of production processes such as paper making and hot pressing. According to the process and production process, it mainly involves aramid paper, aramid honeycomb core material and other products.
Aramid paper is made of paper-making grade aramid fiber as raw material and is formed by wet process. High-performance new materials prepared by high-temperature finishing and other processes. DuPont of the United States successfully developed aramid paper in the 1960s. Because of its excellent properties such as intrinsic flame retardancy, insulation, high temperature resistance, and high strength, it has gradually become a popular choice in the national defense, aerospace, power and electrical, rail transportation, and new energy industries. , electronic communications and other important industries and fields are indispensable for the development of key materials.
Aramid paper
Aramid honeycomb is a bionic structure, which is made of aramid paper through glue coating, lamination, hot pressing, trimming, stretching, shaping and dipping. It is made by a series of complex processes such as , solidification and so on, and has a natural honeycomb hexagonal structure. It is lightweight, high-strength, high-modulus, has strong structural stability and has the advantages of sound insulation, heat insulation, flame retardancy, etc. It can be used as a lightweight and high-strength structural material (mainly as core material), and is used in aerospace, rail transportation, national defense and military industries, etc. Important area. Aramid honeycomb core material has become an important weight-saving material in aerospace, rail transportation and other fields due to its excellent performance; at the same time, combined with prepreg, it occupies an important position in the field of wave absorption.
Aramid honeycomb core material application scenarios
Honeycomb sandwich structure absorbing material formed based on honeycomb core material is an important structural absorbing material. Honeycomb sandwich structure absorbing materials are mainly used in the field of radar stealth; they are composed of aramid honeycomb and wave-transmitting panels impregnated with absorbing agents. They have excellent mechanical properties and wave-absorbing properties. As for the aramid honeycomb sandwich structure absorbing material, its absorbing performance mainly depends on the specifications and dimensions of the honeycomb itself and the impregnated glue system. At present, aramid honeycomb sandwich structure absorbing materials can form strong absorption in the frequency band of 0-18GHz.
Aramid honeycomb core material
2. Main application scenarios
1. The main application scenarios of aramid paper
Depending on the functional application of the product, the downstream application areas of the product mainly include electrical insulation (as insulation material), honeycomb core material (as structure weight loss materials) field.
Meta-aramid paper series products are mainly used in the field of electrical insulation, and a small amount of them are used in the field of honeycomb core materials; transformers are currently the field where aramid paper is widely used in my country. At the same time, with the electrification of my country’s railways and the large-scale construction of urban subways and light rails, higher requirements have been put forward for related equipment of high-speed trains, including high-power traction transformers.
Para-aramid paper series products are mainly used in the field of honeycomb core materials. Compared with the honeycomb core material made of meta-aramid paper, the comprehensive mechanical properties of the honeycomb core material made of para-aramid paper are significantly improved compared to the honeycomb core material of meta-aramid paper. Its strength is 5 times that of steel of the same quality. However, the density is only one-fifth that of steel; however, due to its higher cost, it is generally used in the field of honeycomb core materials that require higher strength.
2. Main application scenarios of aramid honeycomb core materials
Aviation field: After aramid paper honeycomb core material is combined with panels to form a sandwich structure, it can be used as an ideal One of the structural forms, it is widely used in the aviation field. The main application parts include flaps, ailerons, vertical tail leading edges, rudders, canards, fuselage, blades, radome, radome, wall panels, etc.Doors, floors and other components, as well as large rigidity, secondary stress-bearing parts of the aircraft. As the preferred core material for aircraft composite honeycomb sandwich structures, it can reduce the structural quality of aircraft and achieve wave transmission, noise reduction, and heat insulation properties of functional components. According to statistics, there are more than 280 Nomex honeycomb panels in the domestic straight-9 aircraft, covering about 80% of the entire aircraft; the honeycomb panels in the U.S. F-111 fighter jet account for more than 90% of the entire appearance area; the C919 has A large number of honeycomb core materials are used in many parts to meet the need for weight reduction. The demand for aramid honeycomb core materials in a single flight is expected to be more than 10 million yuan.
Ship field: The honeycomb sandwich structure can not only reduce the weight of the empty ship, improve the ship’s maneuverability and impact resistance, but also greatly improve the ship’s corrosion resistance and “stealth” capabilities. In recent years, navies of various countries have also used honeycomb sandwich materials in superstructures such as deckhouses, bulkheads and aircraft ceilings of surface ships to improve the overall performance of the ships in all aspects. The U.S. Coast Guard speedboat uses Nomex honeycomb structure to replace asbestos panels, which not only reduces the weight of the speedboat by more than 9 tons, but also eliminates potential hazards caused by asbestos; the Liaoning aircraft carrier uses more than 100,000 square meters of aramid sheets for the interior, with each The selling price per square meter is 1,500 to 2,000 yuan. It is understood that major research institutes of China Shipbuilding Industry Corporation have begun to use aramid honeycomb panels as lightweight ship interior decoration projects.
In the field of rail transit: Aramid materials can effectively reduce the energy consumption and noise of high-speed trains and have been used in the side panels, roof panels, seats, partitions, luggage racks, and skylight panels of high-speed rail vehicles. It has been applied to reduce the mass of vehicles and increase the speed of trains. High-speed trains with speeds above 200 kilometers per hour require a large amount of aramid paper honeycomb materials. Changchun Passenger Car Factory CRH-5 EMU recommends the use of aramid honeycomb materials as the sandwich structure material of high-speed trains. The annual demand for 10~15mm aramid honeycomb materials reaches 50,000 square meters; in addition, standard EMUs, dynamic and horizontal trains, and new energy low Under the demand for lightweight and comfort, new models such as floor cars also use aramid honeycomb structures in the design of interior parts.
In addition, aramid paper honeycomb core materials can also be used in the manufacture of wind turbine blades, ships and yachts, racing boats, skis, RVs and other products.
3. Industry supply and demand situation
1. Aramid fiber supply and demand situation
The current global aramid fiber production capacity is about 140,000-150,000 tons, of which more than 50,000 tons are meta-aramid fiber and 90,000-100,000 tons are para-aramid fiber. In terms of meta-aramid fiber, about 60% is used in the relatively low-end industrial filtration field in China, and only about 10% is used in the high-end insulation and honeycomb core material fields. In terms of para-aramid fiber, 40% is used for optical fiber reinforcement in China; 20% is used for bulletproof protection, military bulletproof helmets, gloves, etc.; 20% is used in the automotive rubber industry; 20% is used for composite materials.
2. Supply and demand of aramid paper
Aramid paper: According to statistics, the global nominal production capacity of aramid paper is about 20,000 tons/year, and the effective production capacity is about 12,000 tons/year; The global demand for aramid paper is approximately 10,000 tons/year, with DuPont occupying the main market share. According to data compiled by CITIC Securities Research Institute, global aramid paper is mainly used for electrical insulation and honeycomb core materials, accounting for 64% and 34% respectively; benchmarking the global consumption structure, 90.76% of my country’s aramid paper demand in 2020 comes from electrical Insulation, while the consumption of honeycomb structural materials and other composite materials accounts for only 9.24%.
At present, the main domestic manufacturer of aramid paper is Minshida. Minstar is the first aramid paper manufacturer in China and currently ranks second in the global market share of its aramid paper products, second only to DuPont of the United States.
3. Supply and demand of aramid honeycomb core materials
Based on the calculation that 100kg of aramid paper can be made into 3 cubic meters of honeycomb core material, the theoretical production capacity of global aramid honeycomb can reach 204 Ten thousand cubic meters, the theoretical production capacity of aramid honeycomb in the Chinese market can reach 240,000 cubic meters; the effective production capacity corresponding to the aramid honeycomb core material is about 54,000 cubic meters.
At present, the main domestic manufacturer of aramid honeycomb core materials is AVIC Composites. AVIC Composites’ honeycomb production is mainly distributed in Beijing and Nantong. Among them, Nantong’s large-size honeycomb production line has an internationally advanced level and a high degree of automation. Its products are mainly oriented to the civil aircraft field, and are used by foreign trade customers such as Airbus, Boeing, and Yaqi. host.
IV. Conclusion
In recent years, my country has continued to increase policy support for aramid fiber materials and aramid paper. Especially in recent years, the rapid development of equipment manufacturing industries such as high-speed trains, domestic aircraft manufacturing and aircraft carriers in my country has driven the development of aramid insulating paper and aramid paper honeycomb core materials.
With the increase in the application fields of aramid paper, the aramid paper market is expected to have good development prospects. According to third-party public data, China’s aramid paper consumption has increased from 2,742 tons in 2017 to 4,215 tons in 2021. my country’s aramid paper consumption is expected to reach 12,357 tons in 2028. The honeycomb structure is the best load-bearing structure in the aerospace field and will exist in the structural design of aircraft and spacecraft for a long time.
