Roll the rubber on the roller to the left and right to make it uniform. During operation, hold the knife at a 75 ° oblique angle to the horizontal line of the roller to cut the glue, and hold the film with the other hand to make it 15 ° oblique with the roller Rolling with the help of a roller. When the accumulated rubber disappears, the film is pushed into the roller for mixing, so that it is repeated eight times from left to right and right to left.