(1) promote the hardening of adhesives (curing, curing) through heat preservation aging, and improve the composite strength and heat resistance of the composite film.
(2) select the best thermal sealing conditions (temperature, time and pressure) according to the composition structure of the composite film and the thermal sealing state, or improve the thermal sealing method, and carry out cooling immediately after the thermal sealing.
(3) check the preservation period and preservation conditions of the thermal seal layer film. If the thermal seal layer USES the film of the old batch number and the film after thermal seal treatment, special attention should be paid.
(4) increase the thickness of the heat sealing film.
(5) change the type and grade of thermal seal film, and use the inner seal film with anti-pollution thermal seal.
(6) check whether the grade of adhesives meet the requirements (leakage of low molecular substances in the resin, sometimes affect the composition of adhesives).
(7) improve the heat-sealing performance of the thermal seal layer (substrate), control the content of the slippery agent, and adopt LLDPE film.
(8) control the MDI monomer content in the composite anti-blocking masterbatch.
(9) check the treatment degree of hot cover.
(10) replace the ink (preferably with two liquid ink).
(11) change the printing pattern of the packaging bag so that the printing ink part avoids the heat sealing part, or change the heat sealing method. Pay special attention to the metal ink does not print in the seal.