What factors affect the flatness of food packaging bags

Flatness is one of the indicators for measuring the appearance quality of food packaging bags. Apart from material factors, the flatness of food packaging bags is also related to factors such as heat sealing temperature, heat sealing pressure, heat sealing time and cooling effect.

Excessively high heat sealing temperature, excessive heat sealing pressure or overly long heat sealing time will all cause the composite film to shrink and deform. Insufficient cooling can lead to inadequate shaping after heat sealing, fail to eliminate internal stress, and cause wrinkles in the bags. Therefore, the process parameters should be adjusted properly and the normal operation of the cooling water circulation system should be ensured.