Make sure that the film is connected with two sides of the plywood tightly. If not, fix it again from the film pipe inside cutting the bevel by the knife.

• 注意胶膜前后固定夹板是否和胶膜紧密结合，如无法紧密结合，需用美工刀将胶膜纸管内侧切斜角再行放入。