High performance military composite material - aramid fiber

Aramid fibers have the advantages of high strength, high modulus, high temperature resistance, and light weight. Aramid paper and aramid honeycomb core materials prepared from them have broad application prospects. Indispensable key materials in other fields.

The full name of aramid fiber is "aromatic polyamide fiber". It has excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight. Aramid fiber was successfully developed and commercialized by DuPont in the United States in the 1960s. Aramid fibers are not directly used as final products, at least they must be made into fabrics or corresponding composite materials.

The category and performance of aramid fiber have a relatively large impact on the performance of the final product. Aramid fibers can be divided into three types: ortho-aramid, para-aramid (aramid 1414, PPTA) and meta-aramid (aramid 1313, PMTA). Among them, the industrialized products mainly include meta-aramid and para-aramid. Bit aramid two kinds. 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, and is widely used in national defense, aerospace, high-speed trains and electrical insulation and other fields. Para-aramid has better overall performance than meta-aramid, and can be used in the aerospace industry for solid rocket motor casings for missiles and secondary structural materials for large aircraft (such as cabin doors, windows, etc.) , Wing related parts, etc.), body armor, bulletproof helmets, stab-proof and cut-resistant clothing, EOD clothing, high-elasticity parachutes, bulletproof car bodies, armor plates, etc. in the defense industry.

From aramid fiber to aramid honeycomb core material, it needs to go through a series of production processes such as papermaking and hot pressing. According to the process and production process, it mainly involves products such as aramid paper and aramid honeycomb core material.

Aramid paper is a high-performance new material prepared from paper-making grade aramid fiber through wet forming, high temperature finishing and other processes. DuPont Company 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 an It is an indispensable key material for the development of important industries and fields such as electronics and communications.

Aramid honeycomb is a bionic structure, which is made of aramid paper through a series of complex processes such as gluing, lamination, hot pressing, trimming, stretching, shaping, dipping, and curing. It has the six sides of a natural honeycomb shaped structure. Its light weight, high strength, high modulus, strong structural stability, and has the advantages of sound insulation, heat insulation, flame retardant, etc. It can be used as a lightweight high-strength structural material (mainly as a core material), used in aerospace, rail transit, national defense, etc. Important area. Aramid honeycomb core material has become an important weight-reducing material in aerospace, rail transit 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.

The honeycomb sandwich structure absorbing material based on the honeycomb core material is an important structural absorbing material. The honeycomb sandwich structure absorbing material is mainly used in the field of radar stealth; it is composed of aramid honeycomb impregnated with absorbing agent and a wave-transmitting panel, which has excellent mechanical properties and absorbing properties. As far as the aramid honeycomb sandwich structure absorbing material is concerned, its absorbing performance mainly depends on the size of the honeycomb itself and the impregnated glue system. At present, the aramid honeycomb sandwich structure absorbing material can form a strong absorption for the frequency band of 0-18GHz.

1. Main application scenarios of aramid paper

Depending on the functional application of the product, the downstream application fields of the product mainly include electrical insulation (as an insulating material) and honeycomb core material (as a structural weight-reducing material).

Meta-aramid paper series products are mainly used in the field of electrical insulation, and a small amount is used in the field of honeycomb core materials; transformers are currently the field where aramid paper is used more in my country. At the same time, with the electrification of railways in my country and the large-scale construction of urban subways and light rails, higher requirements are put forward for the 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 prepared by para-aramid paper are significantly improved compared with the honeycomb core material of meta-aramid paper, and its strength is 5 times that of steel of the same quality. But the density is only one-fifth of steel; but because of its high cost, it is generally used in the field of honeycomb core materials that require high strength.

2. Main application scenarios of aramid honeycomb core material

Aviation field: After the aramid paper honeycomb core material is combined with the panel to form a sandwich structure, it can be used as one of the ideal structural forms and has been widely used in the aviation field. The main application parts include flaps, ailerons, vertical tail leading edge, Rudder, canards, fuselage, blades, radome, radome, wall panels, hatches, floors and other components, as well as large rigid and secondary stress-bearing components of the aircraft. As the first choice core material for aircraft composite honeycomb sandwich structure, it can reduce the structural quality of the aircraft and realize the wave transmission, noise reduction and heat insulation performance of functional components. According to statistics, there are more than 280 Nomex honeycomb panels of the domestic straight nine aircraft, covering about 80% of the whole machine; the honeycomb panels of the American F-111 fighter account for more than 90% of the entire shape area; C919 in the aircraft A large number of honeycomb core materials are used in many parts to meet the needs of weight reduction. The demand for aramid honeycomb core materials in a single flight is expected to be more than 10 million yuan.

In the field of ships: the honeycomb sandwich structure can not only reduce the weight of the empty ship, improve the maneuverability and impact resistance of the ship, but also greatly improve the corrosion resistance and "stealth" ability of the ship. In recent years, navies of various countries have also used honeycomb sandwich materials for superstructures such as deckhouses, bulkheads and aircraft ceilings of surface ships to improve the comprehensive performance of all aspects of ships. 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 the potential hazards caused by asbestos; The price per square meter is 1500~2000 yuan. It is understood that the major research institutes of CSIC have begun to use aramid honeycomb panels as lightweight ship interior projects.

In the field of rail transit: Aramid materials can effectively reduce the energy consumption and noise of high-speed trains. They have been applied to the side panels, roof panels, seats, partitions, luggage racks, and skylight panels of high-speed rail vehicles to reduce vehicle weight. To increase the speed of the train, a motor vehicle with a speed of more than 200 km/h needs to use a large amount of aramid paper honeycomb material. Changchun Bus Factory recommends the use of aramid honeycomb material as the interlayer structure material of high-speed trains for CRH-5 EMUs. The annual demand for 10-15mm aramid honeycomb materials reaches 50,000 square meters; Under the requirements of light weight and comfort, new models such as floor cars also adopt aramid honeycomb structure in the design of interior parts.

In addition, aramid paper honeycomb core material can also be used in the manufacture of fan blades, ships, yachts, rowing boats, snowboards, RVs and other products.

1. Supply and demand of aramid fiber

At present, the global aramid fiber production capacity is about 140,000-150,000 tons, of which more than 50,000 tons are meta-aramid fibers, and 90,000-100,000 tons are para-aramid fibers. In terms of meta-aramid fiber, about 60% of it 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% of it is used for fiber reinforcement in China; 20% is used for bulletproof protection, military bulletproof helmets, gloves, etc.; 20% is used for 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 about 10,000 tons/year, and the main market share is occupied by DuPont. According to the data compiled by CITIC Securities Research Institute, the 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 appliances. Insulation, while the consumption of honeycomb structure materials and other composite materials accounted for only 9.24%.

At present, the main domestic manufacturer of aramid paper is Minshida. Minstar is the first manufacturer of aramid paper in China, and its global market share of aramid paper products currently ranks second in the world, second only to DuPont of the United States.

3. Supply and demand of aramid honeycomb core material

According to the calculation that 100kg of aramid paper can be made into 3 cubic meters of honeycomb core material, the theoretical production capacity of aramid honeycomb in the world can reach 2.04 million cubic meters, and the theoretical production capacity of aramid honeycomb in the Chinese market can reach 240,000 cubic meters; the effective production capacity corresponds to The aramid honeycomb core material is about 54,000 cubic meters.

At present, the main domestic manufacturer of aramid honeycomb core material is AVIC Composite Materials. The honeycomb production of AVIC Composite Materials is mainly distributed in Beijing and Nantong. Among them, the large-size honeycomb production line in Nantong has an international advanced level and a high degree of automation; its products are mainly oriented to the field of civil aircraft, and foreign trade customers such as Airbus, Boeing, and Yaqi are the main products. host.

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 my country's high-speed trains, domestic aircraft manufacturing and aircraft carriers and other equipment manufacturing industries 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 a good development prospect. According to third-party public data, the consumption of aramid paper in China has increased from 2,742 tons in 2017 to 4,215 tons in 2021, and the consumption of aramid paper in my country 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.

Suiyin Capital will continue to pay attention to the application and development of new materials in the field of national defense and military industry and high-end manufacturing, discover hidden champions and leading companies in the market, use capital to help the cause of national defense and military industry, contribute to the development of the country, and create value for the society.