What are the reasons for the high heat sealing strength but still the phenomenon of falling and breaking the bag?

When the heat sealing temperature is high, the hot air strength is high, but the packaging bag is damaged during the drop test. On the contrary, in the case of low heat sealing temperature, although the heat sealing strength is low, it can also meet customer requirements, but the packaging bag is not damaged during the drop test.This phenomenon shows that when the heat sealing temperature is high, under the action of the pressure of the heat sealing knife, the inner layer carrying the heat sealing functionPEThe film is melted and extruded at high temperature to become thin and brittle, and cause breakage during the drop test. Therefore, in the bag making process, it is necessary to adjust the appropriate heat sealing temperature and pressure to produce products with excellent comprehensive performance.