1, high heat sealing;

2, too large;

3. The heat sealing time is too long;

4. The edge of the upper device is too sharp;

5. The silicon at the bottom is too hard;

6. During the curing process, a part of it permeates into the film. Due to the influence of infiltration, the toughness (resistance) of the matrix decreases, and the bag-making machine improves the brittleness;

7. After cooling, the heat of plastic increases, which increases the tendency of brittleness.