To make China Retort pouch, first of all, we should pay attention to the selection of two-component polyurethane glue that meets the retort requirements according to the sterilization time and temperature. The internal quality of the adhesive, first of all, is the percentage content of the curing agent. Generally, the percentage content of the curing agent should not be less than 2% of the original regulations, otherwise the viscosity of the glue will be greatly reduced. Secondly, the proportion of the curing agent should not be too large. If it is too large, it is easy to cause embrittlement and tearing of the composite film. If the ink or glue is not active enough, or if it is mixed with too much expired residue, the number of groups that can be used to connect the substrate is small, so the adhesion is not strong. The water activity of expired ink and glue is not good, which will lead to the adhesion degree of the boiled bag not meeting the requirements. Be careful not to use expired ink or glue.

Furthermore, the complete cross-linking of various adhesives is different. In order to ensure the complete cross-linking of the glue, it is necessary to adopt different curing processes according to different grades of glue and different uses. Appropriate curing time and temperature make the adhesive react thoroughly and ensure the compound quality. If the curing conditions do not meet the requirements, or the curing time is too short, the peeling fastness after sterilization will decrease and delamination will occur. If the curing time does not meet the requirements, if the time is short, the crosslinking will be insufficient, and the temperature resistance and hydrolysis resistance of the ink layer will be reduced. The basic curing time of China Retort pouch is 60 hours, but sometimes it needs to be adjusted according to the size of China Retort pouch and the ink surface. If the curing time is not enough, the high temperature resistance and hydrolysis resistance of the ink layer will be reduced, so the general high temperature resistant China Retort pouch curing time is 72 hours.