Retard Agent Classification
According to the elements of flame retardant finishing agent, it can be divided into phosphorus flame retardants, halogen flame retardants, nitrogen flame retardants, boron flame retardants, and their mixture flame retardants such as phosphorus-nitrogen flame retardants, phosphorus-boron flame retardants, etc.
According to the type of the finishing fiber, it can be divided into the flame retardant, the wool flame retardant, the flame retardant of the silk fabric, the flame retardant of synthetic fiber and the flame retardant of the blended fabric ( for example, terylene ), etc.
According to the durability of the fabric, the retardant finishing agent can be divided into three categories: non-durable flame retardant finishing agent, semi-durable flame retardant finishing agent and durability retardant finishing agent.
1. Phosphorus flame retardant finishing agent
Phosphorus compounds can produce volatile acids at the initial stage of heating. This acid has a dehydrating effect, which makes the fibers carbonized and shows a flame retardant effect.
Flame retardant is a kind of compound with phosphorus as its main component, which can also be associated with halogen and nitrogen atoms. When phosphorus and halogen coexist, they can produce PBr3 and POBr. They are heavier than halogenated hydrogen and are not volatile, covering on the surface of the fabric to cut off the air, so that they can show strong flame retardant effect.
2. Halogen flame retardant
Halogenated flame retardants commonly use brominated compounds, mainly relying on halogen to produce hydrogen halide gas under high temperature, so that it can dilute oxygen, generate gas shielding effect and destroy the combustible gas in the gas phase to finally achieve the purpose of flame retardant. If mixed with antimonic oxide (Sb2O3), producing hydrogen bromide during combustion, generating three bromine antimony deposits on the fabric, the flame retardant effect can be improved. This kind of flame retardant has the advantages of high efficiency, less dosage and low price.
3. Boron flame retardant finishing agent
As flame retardant in textile fabric, inorganic boric acid and its salts can greatly reduce the ignition performance and combustion. Borax and boric acid mixed at a ratio of 1: 1 or 7: 3 are relatively typical finishing methods. The finished fabric has relatively good flame retardant effect, whose Important indicators of flame retardant can reach a certain level. Moreover, it is economic, non-toxic, but not washable.
4. Intumescent Flame Retardant Finishing Agent
Intumescent flame retardant finishing agent (IFR) is a kind of environmentally friendly green flame retardant without halogen, without antimony oxide as a synergistic agent, the system itself has a synergistic effect. Plastics containing intumescent flame retardant finishing agent in the combustion will generate carbon foam layer in the surface, which achieves the effect of heat insulation, oxygen insulation, smoke suppression and drip proof. It has excellent flame retardancy, low smoke, low toxicity, no corrosive gas, and meets the future research and development direction of flame retardants, thus makes it become one of the most active research fields of flame retardants both at home and abroad.