(Summary description)

The composite bag is made of polyester, nylon, aluminum foil and special polyolefin and other film adhesives through a dry composite process to make a composite film, and then mature, slit, and make a cooking bag. After packaging the food, the composite bag must undergo a high temperature sterilization treatment at 121-135 ℃ for 30-40 min. Not only the film used for bag making must be resistant to high temperature, but also the adhesive used to bond the film must be resistant to high temperature. Otherwise, the adhesive strength between the films will drop and delamination will easily occur after cooking. Nowadays, the adhesive used in the market is mainly used for compounding retort pouches. Recently developed by the Research Institute of Chemical Industry, a 135 ℃ high temperature resistant adhesive for cooking bags, after several on-machine compound tests, its cooking resistance, content resistance, and hygiene and safety are all satisfied with the requirements of domestic manufacturers.

After the food is packaged in the composite fold bag, it must be sterilized at a temperature of 121 to 135 ℃ for 30 to 40 minutes, and the packaging material used must be high temperature resistant. The materials commonly used for retort pouch packaging include polyester (PET), nylon (NY), aluminum foil (Al), cast polypropylene (CPP), etc. The adhesive is a two-component polyurethane adhesive that is resistant to high temperature cooking. A composite film is made through a dry composite process.

The primary process of dry compounding is that the first base material is glued by the mesh roller and then enters the drying tunnel for heating and drying, and the second base material is heated and pressurized by the composite steel roller to be wound into a composite film. Then it is sent to the drying room for heating and curing for a few days, then the bag is made after slitting.