The silicone rubber is kneaded by adding white carbon black, silicone oil, etc. to form a rubber compound, and then rolled out of the sheet. Films produced by calendering have significant differences in physical and mechanical properties in the longitudinal and transverse directions. This phenomenon is a calendering effect. Specifically, the longitudinal tensile strength of the film is greater than the transverse direction, the transverse elongation at break of the film is greater than the longitudinal direction, and the longitudinal shrinkage of the film is greater than the transverse direction. The calendering effect is the result of orientation of the macromolecules and needle-like and flaky compounding agents in the rubber compound in the calendering process. The size of the calendering effect is related to the composition of the rubber compound, calendering temperature, speed, speed ratio and the like. For larger products such as silicone sheets, silica gel sheets.