In the late 20th century, a new type of composite lightweight thermal insulation air duct was developed vigorously. Besides phenolic composite air duct, polyurethane composite aluminum foil air duct and composite glass fiber board air duct are also common. Compared with these composite lightweight heat insulation air ducts, phenolic composite air ducts have the following advantages:

1. Environmental protection

Phenolic foam adopts fluorine-free foaming, and a large number of ODS will escape from polyurethane during foaming, which will cause great damage to the ozone layer. Although there is no ODS escaping from glass fiber, it will do great harm to workers' health in the production process.

keep fit

Cyanide gas will be produced when polyurethane is burned, but 2- methacrylamide, a harmful substance, will be detected when composite glass fiber board air duct is burned. Although the inner surface of composite glass fiber board air duct is coated with polypropylene, glass fiber will inevitably pollute the air duct in processing engineering. If the scattered glass fiber falls indoors with the air supply, it will inevitably cause harm to human health.

3. nonflammable

Phenolic aldehyde is the material with the best fire resistance among organic polymer materials, and the phenolic aldehyde foam sandwich panel made from it is the only composite sandwich panel in China that meets the national fire protection standards for high-rise buildings. However, some composite lightweight thermal insulation air ducts, such as polyurethane composite aluminum foil air ducts, are flammable and produce molten drops when burning.

4. Strong temperature adaptability

Phenolic composite air duct has a wide temperature range and can be used at high and low temperatures (-140℃ to 150℃), unlike some other composite air ducts which can only be used at 50℃.

5. Wide application range

Phenolic composite air duct can be widely used in various industrial and civil buildings and other places with special requirements. Polyurethane is difficult to meet the requirements of fire prevention, so its application scope is strictly limited, and the use of composite glass fiber board air duct in hospitals, food processing plants, basements and other places with dust-proof requirements and high humidity is also greatly limited.