Development history of flame retardant technology
China's flame retardant technology began in the 1950s, starting with the study of temporary flame retardant finishing of cotton fabrics, but its development is slow; Durable pure cotton flame retardant textiles appeared only in the 1960s; In the 1970s, the flame retardant was developed and the flame retardant technology of synthetic fiber and blended fabric was studied; In the 1980s, flame retardant fabrics entered a new development period. Many units developed flame retardant and finishing technology for cotton, polyester and blended fabrics and flame retardant synthetic fibers. Generally speaking, flame retardant fiber products are in the stage of rapid development and research.
definition
Limit oxygen index (LOI)
The so-called limiting oxygen index refers to the minimum oxygen volume fraction required to maintain the complete combustion state of the sample in the mixed gas of oxygen and nitrogen (according to the standard, the fiber shall be spun into yarn with approximate linear density, woven into woven fabric according to the specified warp and weft density, and tested after washing away oil stains, etc.). High oxygen index means that the material is not easy to burn, and low oxygen index means that the material is easy to burn.
Kind
There are many kinds of flame retardant fibers. A large number of studies have proved that the fabric made of flame retardant fibers has certain advantages. Now let's introduce different kinds of flame retardant fibers and their applications.
1. Flame retardant viscose fiber
The flame retardant modification methods of viscose fiber mainly include grafting method, blending method and copolymerization method, in which blending method is a commonly used flame retardant method.
The flame-retardant viscose fiber will not burn in case of fire, forming a dense carbonization layer, protecting the isolation of the fiber from oxygen, and then self-healing. Because the cellulose fiber itself does not melt, the flame-retardant viscose fiber also has the effect of no droplet.
Flame retardant viscose fiber can be woven into comfortable wearing fabric, which is used in underwear, pajamas and bedding. It can also be blended with various flame retardant fibers, such as nitrile, chloroprene and flame retardant polyester. This blend is used for interior decoration and auxiliary decoration materials.
2. Nomex fiber
In the 1960s, DuPont produced Nomex with a limiting oxygen index of about 32. It has permanent flame retardancy and will not melt under high temperature conditions. It has excellent thermal stability. Nomex also has excellent chemical resistance, good mechanical properties, soft feel, good spinnability and excellent radiation resistance. It is widely used in fire-proof work clothes and fire-fighting clothes.
3. Polysulfonamide (PSA)
It belongs to para aramid fiber series. The limiting oxygen index is 33. It is flame-retardant and self extinguishing. There is little smoldering or afterburning. The smoldering and afterburning time, damage length and other indicators of aramid sulfone fiber can meet the flame-retardant requirements of various thermal protective clothing.
4. Flame retardant polyester fiber
There are three main methods of weaving flame-retardant polyester fiber: copolymerization flame-retardant modification, blending flame-retardant modification and flame-retardant finishing. The fiber bath fire does not burn, but still melts and droplets appear.
5. FBI fiber
Polybenzimidazole (PBI) fiber is a non thermoplastic flame retardant fiber developed by American aerodynamics materials laboratory and Celanese company in 1963. It does not burn in the air, and the oxygen limiting index is as high as 40. After being exposed to 600 ℃ flame for a long time, it shrinks by only 10%. Its fabric remains intact and soft. It has good chemical reagent resistance, moisture absorption, hand feel and good textile processing performance, so it has a good application in fire fighting clothes.
6. Flame retardant acrylic fiber
The modification of acrylic fiber can be obtained by copolymerization flame retardant modification, blending flame retardant modification, thermal oxidation method, flame retardant finishing and post-treatment flame retardant modification. Now most industrialized products are woven by copolymerization method. In the past decade, high-rise houses and hotels have been built in China, and the flame retardant requirements for indoor decoration products are becoming higher and higher. Some industrial developed countries have long formulated flame retardant regulations for textiles, stipulating that curtains and hangings in public places such as theatres, hospitals and hotels, and clothing fabrics for the elderly, children and the disabled must meet certain flame retardant standards. The development and application of flame retardant fibers have attracted more and more attention.
source:https://www.tnc.com.cn/info/c-001001-d-3721352.html