[Technology] The Latest Application Status And Control Points Of Aluminum Foil-Containing Solvent-Free Retort Packaging

In the field of solvent-free lamination high-temperature retort packaging, the previous few years have been the difficulty of solvent-free technology, but in recent years, with the continuous maturity of equipment, glue, and technology, 121℃ plastic-plastic lamination structure has been successfully used in the soft packaging industry. In addition, the number of successful mass-produced companies is also increasing in the composite structure of 121°C aluminum-plastic composite and high-barrier materials such as PET/AL and AL/NY.

This process, which was previously considered as one of the biggest bottlenecks in the industry, is the latest development status, problems and process control points?

After testing the four-layer structure PET/AL/PA/RCPP, the composite strength meets the requirements, and mass production will be considered.

We tried the four-layer structure PET/AL/PA/RCPP with solvent-free lamination. The test results showed that the lamination strength was no problem at all, and there was no abnormality after cooking. At the time, the test used Bostik and Henkel glue. I think solvent-free high-temperature cooking There is no problem with compounding in equipment, cooking glue and process. The technology of solvent-free cooking glue is very mature, and PET, AL, PA materials are also no problem, but there is no mass production in the later period, mainly because the thickness of CPP material is different. It has a great impact on the amount of glue, because the solvent-free glue has no initial adhesion. If the material is too thick, the amount of glue around will be low, and there will be a risk of bag breakage, so we dare not mass production .

At that time, the tested start-up speed was about 130m/min, the inner layer of glue was 2.0~2.2gsm, which was glued on the film surface, and the outer layer was glued on the surface of the film was 1.8~2.0gsm. The curing time of the inner layer of CPP alone is 48h, the inner layer strength reaches 8.0N, the outer layer curing time is 24h, the outer layer strength is 2N, the curing temperature is controlled at 55℃, and the quality of the glue can fully meet the product requirements. If the material thickness problem can be solved, we will consider mass production in the future.

There will be more and more room for the development of solvent-free composites, because composite aluminum plating, aluminum foil, boiling, and steaming are no problem at all. The amount of composites such as PET/AL or AL/PA will also increase. For CPP There will also be more and more enterprise tests for layer compounding. As far as I know, a four-layer structure PET/AL/PA/RCPP in a Chongqing enterprise has been mass-produced, but it seems that the temperature has not reached 121°C, only about 118°C.

As for high-temperature cooking products containing aluminum foil structure, I think that more and more standing pouch manufacturers will try and do batch tests, but different product process requirements are different, for example, some require vacuuming, three-side sealing, and Although the product structure is the same, the performance of the inner material RCPP is different. At present, everyone thinks that the vacuumized three-side-sealed cooking bag is the best, and the liquid bag, the nozzle bag or the special-shaped bag are relatively different It is said to be the most difficult of cooking bags, and it has higher requirements for material selection, compounding process, and glue amount.