Aramid 1313 is a kind of hi-tech special fiber. It has the properties of excellent heat resistance and high strength, good air and moisture permeability, long heat-resisting life, high wear resistance, good flexibility and resistance to all kinds of chemical reagent. It is the good and important material to make the fireproof-heat insulation protective clothing.
Aramid 1313 is permanent flame retardant fiber, heat resistance, high strength, high wear resistance, good flexibility, low shrinkage, stable chemical structure, combustion without drop, do not produce poisonous gas, etc.
Due to the Aramid 1313 has the character of high breaking strength and elongation, the aramid fabric has very good wear resistance. Meanwhile, because of the low stiffness and high elongation, the aramid1313 owns the same spinning property as the ordinary fiber and has soft handfeel and comfortable wear.
(1).Heat resistance property. Among the crystal of Aramid 1313, the hydrogen bonds were arranged in two planes, thus forming a three-dimensional structure of hydrogen bonds. Due to the strong hydrogen bonding actions, the aramid has very stable structure and can keep the strong strength under the general high temperature state. Under the operating temperature of 177~200℃，the aramid fabric can still maintain 65%~70% of the original strength after 20000h.
(2).Flame retardant property. Due to its inherent structure features, the aramid 1313 will not continue the ignition in the flames, the limit oxygen index of the Loi is 29%~32%. The Aramid 1313 belong to the flame retardant fiber, it will not burn in the air and not support burning, it has self-extinguishing and no molten drop. When the temperature exceeds 400℃， the fiber will become embrittlement and carbonization gradually, until decomposition, but no molten drop. The smoke density and toxic gases emitted during combustion of the Aramid 1313 are less than other fibers.
(3).Heat-moisture comfortability. The heat-moisture comfortability is the condition that people are satisfied with the thermal environment. The basic condition for the human thermal comfort is to keep the body’s heat balance, namely the balance of energy exchange between the heat generated by the human body itself and the human body heat to the environment. Under the circumstance of high environment temperature(>33℃)，there is very small temperature difference between the human body and the environment, even the existence of an inverse temperature difference which can be regulated by human body itself. At this time, the moisture permeability of the clothing is particularly important. By testing the wettability and the clothing comfortability of the several types of flame retardant fabrics, It can be concluded that the heat-moisture comfortability of the Aramid is much better than the other textile fabrics.
(4).Chemical resistance property. Aramid 1313 has very good chemical resistance. It has good resistance to most of the acids, the strength of the fabric just decreased slightly after a long time immerse in the hydrochloric acid, nitric acid and sulfuric acid; It has good resistance to the alkali, however the strength will decrease after a long time immerse in the sodium hydroxide; It also has good resistance to most of the bleaching agent and solvent, the strength will lost a little after immersing in the sodium hypochlorite; The property of the aramid 1313 is stable to the oxide, under the action of the 250℃ corrosive gas, the strength can remain 60% of the strength when kept at the room temperature; Above the acid dew point temperature, the fabric has an action of antioxidation, however, below the acid dew point temperature, the strength of the fabric will decrease due to the concentrated sulfuric acid were gathered in the fiber.
(5).Radiation-proof property. The aramid 1313 has very good resistance to the radiation，The residual radiation-proof strength is still very high after the irradiation of βrays andγrays. For example, under the radiation of the 50kv X rays for about 100h, the aramid strength can remain the 70% of the original fabric, however the polyester and nylon will be the powder. So it is appropriate to make the workwears which were used in the flammable explosive environment and the materials which were used in the high temperature by using the aramid 1313.