The reason why the sealing strip is flame retardant is that a sealing strip flame retardant is added to the raw material of the sealing strip. After adding this flame retardant, the sealing strip releases water when it is decomposed by heat and absorbs a large amount of latent heat, which reduces the amount of latent heat. The actual temperature of the flame on the surface of the material causes the polymer to degrade into flammable low molecules, thereby reducing the speed of the flammable low molecules, and releasing a large amount of water vapor, reducing the concentration of oxygen and flammable gases near the surface of the polymer, making the sealing strip It is difficult for the surface to continue to burn.