Japan Successfully Develops Nano Structure Fiber For Fire Fighting

As a comprehensive development institution of new energy and industrial technology (NEDO)

The object of development is to compounded ultrafine particles of nanometer size by heat conduction.

*1 nanostructured fibers: a general term for nanofibers with surface and internal structure controlled.

*2 aramid fiber: one of the high functional fibers with high strength, heat resistance, dimensional stability and drug resistance.

1 background of development

In recent years, firefighting has begun to implement personal property assistance and prevent the spread of fire into the building, and finally to the limit near the source of fire, and effectively extinguish fire.

The following two main functions are required to ensure the safety of firemen. (1) when carrying out fire fighting activities, the fire clothing must have high temperature insulation to the flames (2) the fire-fighting clothing should have the comfort of reducing the body burden in fire fighting activities and preventing heat syndrome.

However, so far, it is very difficult for a fire-fighting clothing to focus on both high temperature and heat comfort regardless of its thermal insulation or comfort.

Under such circumstances, the Tinto products company and Hosokawa Meketa company have been one of the subjects of NEDO's nanotechnology, advanced materials practical research and development (nanotechnology challenge), and jointly engaged in the development of advanced fire-fighting clothing with excellent insulation, heat resistance and comfort with nano structured fibers.

In addition, the analysis and evaluation methods of nano structured fiber, particle dispersion method, etc., Tokyo Institutet of Technology professor Guoka Akihiko, Tokyo University Agricultural & Technology professor Shinya Hidehiro also in the research and development process guidance, achieved the production, the official, the study three simultaneously cooperation.

2 content of development

Effective development of advanced fire-fighting clothing to improve the function of fiber materials.

(1) development of multifunctional nanoparticle and particle surface treatment technology

Hosokawa Meketa company is responsible for the development of multi-functional nanoparticles and the development of particle surface treatment technology, and establishes the conditions for developing and manufacturing nanoparticles with excellent dispersion and heat insulation to aramid fibers.

(2) development of nanostructured fibers

Tek's product company has developed nanostructured fibers that have been combined with Hosokawa Meketa's multi-functional nanoparticles into aramid fibers.

And the development of the nano structure fiber cloth as a lining material for the use of fire fighting layer structure.

3 fiber characteristics

The material developed is in the fire fighting clothing consisting of 3 layers of structure called the "outer layer", "middle layer" and "insulation" (inner layer). The material used in the insulation layer is the insulation material which is equivalent to the heat insulation function of the skin. This is used in the aramid fiber "special Kenuo pull *" fiber, using the high particle surface treatment technology of Hosokawa Meketa company and the mixing and spinning technology of the Tek Kenuo product company, evenly dispersing nanometer size carbon ultrafine particles, greatly improving the thermal conductivity ratio than the ordinary aramid fiber, and by being given the thermal diffusion function, the technology can improve the heat insulation performance of the fabric.

Due to the thermal diffusion function, the heat from the fire fighting clothing is dispersed from exposure to flame and heat. Compared with that without using nano structured fibers, it shows about 40% of the *3 damage of fire. In addition, compared with the traditional fire-fighting clothing, if the same hot water is used, the cloth can be lighten by 15%.

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The results of the performance test have been successfully applied to a high level with the opposite function of the comfort performance *6 of the North American fire service *5, known as the world's most stringent *4, and the world's highest level Japanese fire suit.

*3 here refers to 2 degree of fire (injury site: basal layer to dermis) and 3 degree fire (injury site: subcutaneous tissue).

*4 was used by the international standardization agency as an international standard for ISO11613:1999 "firefighters" in 1999.

*5 based on the "ThermalPerformanceProperty (TPP)" test based on ISO17492.

*6 based on the "total heat loss: TotalHeatLoss (THL)" based on the evaluation of ASTMF1868, this thermal stress mitigation test is conducted.

4 future prospects

In the future, the technology of mass production of fiber materials will be established and promoted based on the application of fire-fighting clothing.

Moreover, the aramid fiber based nanostructured fibers can change the kinds of functional nanoparticles dispersed inside the fibers, and can also give various functions such as conductivity and electromagnetic shielding without damaging the physical properties of aramid fibers.

For example, the thermal shrinkage inhibition can be achieved together with the inorganic composite nanoparticles added with TiO2 and SiO2.

We will continue to look forward to and expand many other uses of organic materials that have not yet been developed.