The reason:
(1) The heat sealing temperature is too high.
(2) Too much pressure.
(3) The heat sealing time is too long.
(4) The edge of the upper seal is too sharp or the coated PTFE is damaged.
(5) The bottom sealing silicone rubber is very hard.
(6) In the process of composite and curing, a part of the adhesive into the film. Due to the penetration of the adhesive, the toughness (impact resistance) of the substrate decreases, and the brittleness increases.
(7) After cooling and placing, the thermal sealing strength of the plastic composite packaging bag increases, and it also tends to become brittle.
Solutions:
(1) According to the heat sealing characteristics of the inner sealing layer material, choose the appropriate processing temperature, pressure and heat sealing time.
(2) Improve the surface state of the upper heat sealing knife, so that the surface of the sealing device is smooth.
(3) With PTFE cloth covered in good condition.
(4) Choose the right hardness of silicone rubber pad.
