Formulation design of flame retardant nylon lining coating composite production line
DATE：2021/6/24 8:36:09 / READ： / SOURCE：This station
Formulation design of flame retardant nylon lining coating composite production line
In the manufacturing process of flame retardant nylon, the requirements of flame retardant grade, mechanical properties of materials, surface properties, processability and coloring properties of products should be considered. According to the use requirements, determine the type and dosage of flame retardant. The selection of additives and technological conditions are very important. Lining coating composite production line www.handern.comThe selection principle of flame retardant is mainly from the aspects of flame retardant efficiency, product performance, toxicity and so on: 1; 2. It has good compatibility with nylon; 3. High decomposition temperature, no decomposition at nylon processing temperature; 4. Excellent durability, no obvious surface migration; 5 has little effect on the mechanical properties of the materials (most flame retardants will reduce the properties of the materials); 6 has little influence on the electrical properties of products (some flame retardants have great influence on the electrical properties of products, thus limiting the application in the field of electronic appliances); 7. The corrosion to the equipment shall be as small as possible (generally speaking, the halogen flame retardant produces HX due to decomposition, which has certain corrosion to the equipment); 8. Non toxic, odorless and pollution-free; 9. Low price (the price and dosage of flame retardant are the main factors of material production cost). Lining coating composite production line www.handern.com
Flame retardant is divided into main flame retardant and auxiliary flame retardant. The main flame retardant is the one with good flame retardant effect and plays the main role; The auxiliary flame retardant is not very ideal, can not be used alone, with obvious effect when used together. The auxiliary flame retardant plays the role of smoke suppression and anti dripping. The main flame retardants are halogen, phosphorus, nitrogen, inorganic hydroxide and so on. The auxiliary flame retardant is synergist, such as sb: O, zinc borate, etc., and the other is smoke suppressant, such as ZnO, ZnS, FeO: etc（ 1) Synergistic effect of flame retardants in a formula, sometimes need to use several flame retardants, in the selection of flame retardant combination, we must know which flame retardant combination has complementary effect, which flame retardant effect is mutually offset. Lining coating composite production line www.handern.com
The flame retardant effect of halogen and antimony: sb2o: is very poor when used alone, but it has obvious effect when used together with halogen flame retardant. This is because the halogen decomposed during combustion reacts with SB0 to produce sbx: and Sbox: while the density of sbx: is high, which has obvious oxygen isolation effect, and has the function of capturing free radicals, increasing the flame retardant effect of halogen gas phase. The ratio of halogen system to antimony system is generally 3:1. Lining coating composite production line www.handern.com
Halogen and phosphorus: in the halogen phosphorus composite system, halogen flame retardants mainly produce gas phase flame retardant effect, while phosphorus flame retardants produce metaphosphate when burning, resulting in solid phase flame retardant effect, forming a complete gas-solid flame retardant system. At the same time, the reaction between halogen and phosphorus can also produce PX and PX gas, which has higher density than HX and is not easy to diffuse, and encircles the flame surface to play the role of oxygen isolation. The ratio of halogen and phosphorus is generally 3:2. Lining coating composite production line www.handern.com
Phosphorus and nitrogen series: nitrogen series flame retardants can promote the carbonization of phosphorus series compounds, that is, the effect of carbonization. The carbon layer covers the surface of the object to be burned, which has the effect of oxygen isolation, thus improving the flame retardant effect. Phosphorus system and antimony system: the synergistic mechanism is similar to halogen system and antimony system.
Red phosphorus, metal oxide and polyphosphate amide also have synergistic effect. SBO: and zinc borate have synergistic effect: zinc borate has anti dripping effect, and the addition of zinc borate can reduce the amount of sb2o: and the amount of sb2o: can be reduced. Red phosphorus and carbon black have synergistic effect: when carbon black is added, the amount of red phosphorus can be reduced www.handern.com
There are many antagonistic effects among flame retardants. The combination of flame retardants can produce synergistic effect and improve the flame retardant effect. However, when some flame retardants cooperate with each other, they will counteract the flame retardant effect. Special attention should be paid when using: A. halogenated compounds should not be mixed with organosilicon, which will reduce the oxygen index of the flame retardant system. b. Brominated flame retardants should not be used together with zinc stearate, otherwise the brominated flame retardant effect will be reduced. C. red phosphorus and organosilicon are not suitable for mixed use. d. It is not suitable to add CaCO: and MgCO in bromine flame retardant system, otherwise the flame retardant effect will be reduced. Lining coating composite production line www.handern.com
Author：admin