How Much Do You Know About Viscose-based Carbon Fiber And its Applications?

 

Viscose Fiber

 

Viscose fiber is a regenerated cellulose fiber, also known as rayon, which is made from natural fibers such as wood, hemp and cotton through pulping, sulfonation, aging and spinning.

 

 

02 Viscose-based Carbon Fiber

 

Viscose-based carbon fiber is a fiber material with carbon as the main component, which is made from viscose fiber as raw material, and then subjected to high-temperature heat treatment above 800°C in a non-oxidizing atmosphere after low-temperature heat treatment.

 

Viscose Based Carbon Fiber Felt

 

03 Performance Of Viscose-based Carbon Fiber

 

In addition to the advantages of high specific strength, high specific modulus, chemical corrosion resistance, and good lubricity, viscose-based carbon fiber also has the characteristics of low specific gravity, high purity, large elongation at break, softness, good weavability, small thermal conductivity, large specific surface area, and easy activation. It plays an irreplaceable role in the aerospace industry and cutting-edge military technology.

 

04 Breakthrough In The Localization Of High-performance Viscose-based Carbon Fiber

 

In the 1980s, my country’s top strategic weapon, intercontinental missiles, faced the last two long-standing technical difficulties. One of the “roadblocks” is aerospace-grade high-purity viscose-based carbon fiber. As a key material for the heat protection layer of intercontinental missile warheads, aerospace-grade high-purity viscose-based carbon fiber is like a “protective suit” for missiles. It can protect missiles from high-temperature “damage” and is a “new coat” for strategic weapons such as rockets and missiles. The raw material requirements are extremely high and the preparation technology is extremely difficult. At that time, only the two superpowers, the United States and Russia, had it, and imposed strict embargoes and technical blockades on my country.

 

“Every citizen has a share of responsibility for the success or failure of a country. Research should focus on solving key technologies and serving the national economy and people’s livelihood.” This is what Professor Pan Ding often says. After studying under Professor Qian Baojun, the famous founder of my country’s chemical fiber discipline, Pan Ding took over the baton of scientific research and served the country from his mentor and devoted his life to focusing on carbon fiber.

 

Professor Pan Ding

 

After years of hard work, the research team led by Professor Pan Ding used cotton pulp-based fibers that were rejected by foreign countries as raw materials. Through original preparation technology, they solved the six major problems of determining the quality index of raw silk, carbonization of sparse weft bands, organic-inorganic hybrid catalysis, continuous purification process, low-temperature heat treatment of air medium and two-stage coke removal, and successfully developed aerospace-grade high-purity viscose-based carbon fiber that is superior to similar products in the United States and Russia, providing key technical support for the flight of strategic weapons.

 

Professor Pan’s move not only filled the domestic gap, making my country the third country in the world to master the development technology of aerospace-grade high-purity viscose-based carbon fiber, but also contributed to the upgrading of my country’s national defense modernization and the defense of the achievements of national economic modernization.

 

For this reason, this scientific research achievement won the honor of the top ten scientific and technological progress of Chinese universities in 2001 and the second prize of the National Science and Technology Progress in 2003. The project has also received commendations and awards from the State Council and the Central Military Commission, as well as encouragement and praise from the main leaders of the National Defense Science and Technology Commission and the National Space Administration.

 

05 Application Of Viscose-based Carbon Fiber

 

• Application In Strategic Weapons (One Of The Most Important Application Directions)

Dongfeng-31 Intercontinental Ballistic Missile

 

 

Aerospace-grade high-purity viscose-based carbon fiber is the main skeleton material for the large-area heat protection layer of missiles, and its performance is related to the missile’s hit accuracy. The high-speed flight of the missile at high altitude and the gravity acceleration of the missile’s fall back into the atmosphere cause the friction between the missile shell surface and the air to reach a temperature of tens of thousands of degrees. Any high-temperature resistant metal will vaporize at such a high temperature, causing the missile to lose balance or the navigation system to make mistakes. In this case, aerospace-grade high-purity viscose-based carbon fiber becomes the “protective clothing” of the missile.

 

The United States and Russia use viscose-based carbon fiber reinforced phenolic resin composite materials for strategic weapons insulation (protection) materials, which takes advantage of the ablation resistance of viscose-based carbon fiber and the high residual carbon content, high coking strength and low smoke generation of phenolic resin. The superposition of the performance of these two materials makes the composite material have excellent comprehensive performance, and it is still an irreplaceable heat protection material today. The United States and Russia still retain the production capacity of 100 tons of viscose-based carbon fiber per year, and this is the reason.

 

(2) Thermal Insulation Materials

 

Viscose Based Carbon Fiber Felt

 

The thermal conductivity of a material is proportional to its density. Low-density viscose-based carbon fiber gives it excellent thermal insulation properties. In addition, carbon materials rely on lattice waves to transfer heat, and its La is small, which also makes it have thermal insulation properties. Soft and hard carbon felts have been widely used as thermal insulation materials.

 

(3) Various Types Of Heaters

 

The thermal conductivity and soft processability of viscose-based carbon fiber are used to manufacture various types of heating equipment. Carbon fiber, carbon ribbon, carbon cloth and carbon paper can all be used as heating elements and can be composited with rubber, plastic and inorganic insulating materials to manufacture heating equipment of various shapes, different powers and different uses. Russia has been quite successful in the application and development in this area.

 

(4) Medical Biomaterials

 

Medical biomaterials such as medical electrodes and probes, ligaments, bone splints and artificial bones are manufactured by using the compatibility of viscose-based carbon fiber with organisms. Trauma bandages have been put into practical use in Russia and other countries.

 

(5) Protective Materials

 

Viscose-based carbon fiber has good electrical conductivity and can be used to make anti-static and anti-electromagnetic wave clothing.

 

(6) Activated Carbon Fiber

 

After activation treatment, viscose-based carbon fiber can be made into activated carbon fiber, which has good flexibility and deep processing ability, and its adsorption performance is also under research.

 

06. Current Problems Of Viscose-based Carbon Fiber

 

The United States, Russia, Belarus and other countries have a production scale of hundreds of tons. However, due to the disadvantages of viscose-based carbon fiber such as high pollution in the raw silk production process, complex production process, low strength, and low cost performance, its application range is limited.

 

07. Prospects For The Development Of Viscose-based Carbon Fiber

 

In recent years, the development of new viscose solvents, new processes and new varieties has reduced production costs. At the same time, due to the indicators such as light weight, pure quality, high elongation at break, and low thermal conductivity that are necessary for aerospace materials, viscose-based carbon fiber is better than polyacrylonitrile-based carbon fiber and asphalt-based carbon fiber, so viscose-based carbon fiber still has irreplaceable application prospects.