The high temperature resistant conveyor belt is actually a longitudinal water ripple along the grain, which appears on the entire length or part of the belt. Shun grains are often encountered during the use of conveyor belts. In fact, the occurrence of ran grains is a typical quality defect. Where there is a woven grain, the cloth layer of the belt is deformed in a wavy shape, and the slight one is hidden on the inner surface of the adhesive layer. There is no obvious performance; in severe cases, the upper and lower cover glue will also be uneven, and it is difficult to repair the smooth lines. The harm of straight grain is relatively large, not only a general appearance quality problem, it will seriously affect the service life of the belt. The service life of the high temperature resistant conveyor belt with smooth grain should be reduced from 10000h to 2000 ~ 3 000 h. In addition, the joint of the flame retardant conveyor belt with smooth grain is also difficult, and it is easy to loosen after being connected.