What is the reason for the heat sealing and delamination of the composite packaging film?The general reasons for heat-sealing and delamination of composite packaging films are as follows: 1, The choice of the adhesive is wrong or the heat resistance of the adhesive is poor. 2, The ratio of curing agent is out of balance. The possible reasons for the imbalance of the curing agent are as follows:a.human error in matching;b.The ambient temperature is too high;c. The solvent contains moisture, alcohol or activity——OHGene;d.The solvent in the ink has not dried sufficiently. 3, insufficient curing or the temperature is too low. 4, Insufficient drying. Since the solvent does not volatilize cleanly during printing or compounding, there are many residual solvents. Although these solvents may not contain active chlorine and will not affect the cross-linking reaction of the adhesive, the solvent will swell the adhesive layer and may be exposed to high temperatures. It will vaporize, so although it has little effect on the composite strength at room temperature, it may cause heat-sealing delamination. 5The influence of printing ink. One is that the undeveloped active solvent in the ink, the resin or the additive in the ink consumes a part of the curing agent, which causes the imbalance between the main agent of the adhesive and the curing agent to cause the heat-sealing separation layer. Heat-sealing delamination may occur when heat-labile polyester amine inks are used or chlorinated polypropylene inks are used in high-temperature heat-sealing applications.
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