The flame retardant mechanism of textile is as follows:
Cover theory: (1) some flame retardants in the case of higher temperature (> 500 ℃), on the fiber surface layer, and have isolation effect, in addition to hinder the supply of oxygen, can also prevent the spread of the combustible gas to the outside, so as to achieve the purpose of the flame retardant. Borax - boric acid.
(2) gas theory: the flame retardant can decompose non-combustible gases such as CO2, HCl and H2O at the burning temperature, and dilute the concentration of flammable gas to the concentration of the flame.
(3) heat theory: viewpoint 1: the flame retardant has the effect of melting and sublimation at high temperature, thus preventing the spread of combustion; Viewpoint 2: flame retardant can heat the fiber rapidly, so that the fabric can not reach the burning temperature;
(4) the catalytic dehydration theory: the existence of flame retardant, changed the pyrolysis mechanism of the fiber, the fiber before cracking temperature and dehydration or crosslinking effect in great quantities, make the quantity of combustible gases and volatile liquid is greatly reduced, and make the solid carbon greatly increases, so will be suppressed with flame combustion.
There are three approaches to the corresponding flame retardant mechanism.
(1) burnout method: the flame retardant and cellulose fiber are combined with ionic bond or covalent bond, so that the flame retardant effect can be obtained in the fiber without dissolving.
(2) liquid method: the flame retardant is added directly to the spinning solution.
(3) copolymerization method: the flame retardant is added to the polymer chain segment, so that the fabric has the qualified fastness of washing, bleaching and perspiration, which is not absorbed by the skin.
Printing and dyeing factories mainly adopt the first method.
Testing of flame retardant properties of textiles.
The flame retardant test for textiles is as follows:
(1) test of fabric combustion performance: it is divided into vertical, horizontal and 45-degree combustion test.
(2) limit oxygen index test.
(3) flame retardant and wash test.
For flame retardant fabric, we also need to test the strength and tear strength according to the standard.
