What is flame-retardant material
Flame retardant materials are materials that can inhibit or delay combustion but are not easy to burn themselves. They are widely used in clothing, petroleum, chemical, metallurgy, shipbuilding, fire fighting, national defense and other fields. Flame retardant materials mainly include organic and inorganic, halogen and non-halogen. Organic is bromine, nitrogen and red phosphorus and compounds as a representative of some flame retardant, inorganic is mainly antimony trioxide, magnesium hydroxide, aluminum hydroxide, silicon and other flame retardant system.

Flame retardant material products can be divided into flame retardant fabric, flame retardant chemical fiber, flame retardant plastic, flame retardant rubber, fire retardant coating, flame retardant wood materials and flame retardant paper, inorganic non-combustible filling materials and other 7 categories.

Flame retardant material grade
Flame retardant material grade UL94 flame retardant grade has 12 kinds: HB, V-0, V-1, V-2, 5VA, 5VB, VTM-0, VTM-1, HBF, HF-1, HF-2.
Flammability UL94 is the most widely used standard for flammability of plastic materials. It is used to evaluate the ability of materials to extinguish after ignition. There are a variety of ways to judge whether a drop burns, according to the rate of combustion, the duration of combustion, the ability to resist droplets, and whether the droplets burn. A number of values can be obtained for each material being tested, depending on its color or thickness. When a material is selected for a product, its UL rating shall meet the thickness requirements of the wall part of the plastic part. UL grade should be reported with thickness value, it is not sufficient to report UL grade without thickness.

The flame retardant grade of plastics increases step by step from HB, V-2, V-1 to V-0:
1. HB: the lowest flame retardant grade in UL94 standard. Requires a combustion rate of less than 40 mm per minute for samples 3 to 13 mm thick; For samples less than 3 mm thick, the combustion rate is less than 70 mm per minute; Or go out at the 100mm sign.
2, V-2: after two 10-second combustion tests on the sample, the flame will be extinguished within 60 seconds. You can have combustion falling down.
3, V-1: after two 10-second combustion tests on the sample, the flame will be extinguished within 60 seconds. No incendiary material can fall.
4, V-0: after two 10-second combustion tests on the sample, the flame will be extinguished within 30 seconds. No incendiary material can fall.

Three kinds of polymer flame retardant materials
Before containing halogen flame retardant materials is the most widely used, but containing halogen flame retardant material has an obvious shortcomings, it is containing halogen flame retardant materials after combustion will produce large amounts of toxic gases, these gases will not only cause certain harm to people's physical, but also affects the environment, so now there are more environmentally friendly flame retardant materials to replace the containing halogen flame retardant materials. Especially after entering the 21st century, the emergence of various polymer flame retardant materials makes our life more beautiful.
Polymer flame retardant materials are usually divided into three categories, namely polymer flame retardant materials, hydrated metal oxide flame retardant materials and phosphorus-silicon added flame retardant materials.

Polymeric flame retardant material
The so-called polymer flame retardant material refers to a new type of composite flame retardant material which is dispersed in the polymer by special technology. This new flame retardant material has the advantages of low density and high mechanical strength, so it can better play the flame retardant effect. The emergence of this new flame retardant material not only greatly strengthens the flame retardant, but also makes the flame retardant material more widely used, such as can be used as heat-resistant material, which makes the new flame retardant material more competitive in the market.

Hydrated metal oxide flame retardant material
In fact, this kind of flame retardant material is a kind of filler, now is also very widely used, such as magnesium hydroxide or aluminum hydroxide and so on. The first is that the use cost is very low, and the other is that this kind of flame retardant material has strong environmental protection, does not produce toxic gases. The main principle is to use magnesium oxide after heat release of water, can absorb heat, so as to achieve the purpose of flame retardant.

Phosphorous silicon added flame retardant material
It is mainly divided into two types of flame retardant materials, one is organic silicon flame retardant, the other is inorganic silicon flame retardant, these two kinds of flame retardant has the advantages of high efficiency, environmental protection, non-toxic, by the majority of users praise and favor.

Flame retardant materials urgently need strict standards and supervision
In recent years, domestic bus fire incidents are not rare. The flame retardant standard of bus interior materials is too low, which is an important reason for the loss of people and property.

Zhou Zhengmao, secretary-general of China Flame Retardant Society, told China Chemical News that the low standard of flame retardant materials exposed by the bus fire is just the tip of the iceberg. In China, lax supervision, inadequate enforcement of laws and regulations and market chaos are the core problems that need to be solved. If these problems are not handled properly, they not only hinder the healthy development of flame retardant material industry, but also produce a large number of fire hazards.

As an expert on flame retardant materials, Zhou Zhengmao believes that after decades of development, the foundation of China's flame retardant chemical industry has been laid. In terms of technology, product performance, quantity and variety, domestic flame retardant chemical products can meet the needs of the domestic market. There are as many as three or four thousand flame-retardant material production enterprises, and more than 100 large-scale enterprises, and some leading enterprises also have a certain influence in the world.