The cause may be that the burrs are too thick and are torn during trimming, or the mold fit is too tight. The burrs are stuck by the mold when the mold is removed, and are easily torn from the product and the burrs. The force is uneven when the mold is removed, and it is easy to Tear the product. Sometimes the mold cavity is roughly processed, or the rubber material sticks to the mold. When the mold is released after vulcanization, it is difficult to demould and the product is easy to tear. In addition, if the vulcanization temperature is too high, the product will become brittle and easy to tear. In view of the above abnormalities, the solutions can be solved from the following aspects: the mold processing accuracy must be controlled so that the cavity roughness Ra is less than 0.8, the fitting gap should not be too large, the vulcanization temperature should be controlled between 170 degrees left, and the rubber material must be weighed accurately.