Application of Expandable Graphite in Flame Retardant and Fireproof Field
Since the commercialization of self-Expandable Graphite, has been more than 30 years of history. With the development of science and technology, the application of Expandable Graphite is more extensive, especially in the field of sealing, flame retardant and anti-electromagnetic interference and other fields. Today, I mainly introduce the application of Expandable Graphite in the field of flame retardant and fireproof, as well as the direction of development of Expandable Graphite.
Expandable Graphite as a flame retardant material, compared with the traditional flame retardant material has the following characteristics: in the fire, the smoke less; no low, does not cause secondary fire; and instant expansion force, flame retardant effect. So especially by domestic and foreign users of all ages.
Expandable Graphite in the field of fire retardant and fire protection is mainly used in the following areas:
1. fire seal
Due to the expansion of the Expandable Graphite, high temperature resistance and thermal insulation, making it an excellent sealing material, and is widely used. At present there are two main forms: the first is the expansion of graphite and rubber materials, inorganic flame retardants (aluminum hydroxide), accelerators, curing agent, reinforcing agent, such as mixing, into a variety of specifications Of the expansion seal. Mainly used for fire doors, fire glass windows and other occasions. This seal has the effect of blocking the flow of smoke from beginning to end. The other is the use of glass fiber as a carrier using some kind of binder will be Expandable Graphite bonded to the carrier, it is mainly used in the manufacture of fire doors.
2. fire bag, fire blocking material, fire ring
Because the expansible graphite in high temperature conditions with a high expansion rate, can be made fire bags, fire blocking material, as an effective expansion of flame retardant materials for building fire blocking. Such as sealing construction pipes, in the cable, gas pipeline fire to prevent the spread of fire.
3. Fire board
Due to the small density of Expandable Graphite, crystal stability, commonly used in firewood mixture, the purpose is to increase the fire resistance of the plate to reduce the density of the board to enhance the insulation performance. Expanded graphite is often used as a flake, which can be used to make fire-resistant panels for walls and other combustible substrates in which small-sized natural flakes of graphite particles can be directly pressed into boards, Occurs, the fine particles of graphite can be expanded to form a more dense fire barrier layer.
4. Flame retardant coating
In recent years, Expandable Graphite is being tried to be used in flame retardant coatings, which impart excellent thermal expansion to the coating. The United States recently proposed a fiber reinforced materials, Expandable Graphite, solid endothermic materials, polymer adhesives and other components of the flame retardant coating, can be used for fiberboard, wood gutter coating. The coating overcomes the shortcomings of previous coatings that are prone to flue gas. In the fire can quickly expand the formation of light carbon layer, and the release of gas (such as: SO2, NO, etc.) less. Can effectively protect the substrate from fire protection. But the black surface of the graphite surface limits its use. Through the surface modification to change its color, increase the color of paint varieties, so that the color can be accepted by the public, is the focus of the study.
5. Flame retardant plastic
The expanded carbonized layer formed by Expandable Graphite carbon has excellent heat insulating properties and high temperature resistance. Expandable Graphite is the only swelling agent found so far available under harsh conditions and with sufficient expansion strength. The application of Expandable Graphite in flame retardant plastics is primarily the use of expandable and adiabatic properties of Expandable Graphite. Such as: dispersed in the polyurethane foam in the expansion of the role of graphite can prevent burning, weaken the fire, but also play a role in insulation.
At present, a large number of reported expansive graphite for flame retardant polyurethane, flame retardant polyolefin, flame retardant rubber, flame retardant polyphenylene plastic, flame retardant carbonate oligomers, flame retardant asphalt and flame retardant cables and so on.