In the process of meat food production and processing, there are always two cooking processes, namely, high temperature and high pressure sterilization and low temperature and normal pressure sterilization. Meat food sterilized at low temperature has a fresh and tender taste, and various nutrients are well preserved, because the heating temperature is low and the fiber of meat is not destroyed. However, because it only kills pathogenic bacteria, there are still a lot of spoilage bacteria, which not only has a short shelf life, but also is easy to cause losses in the circulation field. High-temperature sterilized meat products shrink excessively because of high heating temperature, and the taste is not as good as that of low-temperature sterilized products. However, due to killing all bacteria and eliminating the internal cause of corruption, the shelf life can be greatly prolonged.

If high-barrier packaging is used for high-temperature sterilized meat food, it not only has a long shelf life at room temperature, but also is convenient for transportation, storage and sales, which is very suitable for the consumption needs of modern society. Therefore, vigorously developing the production of meat products that can be stored at room temperature is an important product development direction of the meat food industry. The packaging industry conforms to this development trend and makes some achievements and innovations, which can not only meet the needs of the food industry, but also win a broad market for itself.

It is understood that the earliest packaging of meat food that can be preserved at room temperature is canned food, which is an iron can made of tinplate, and then glass bottles are used as the outer packaging. Tinplate and glass bottles are resistant to high-temperature cooking and have high barrier properties, and the shelf life of cans can reach more than 2 years. Tinplate cans and glass bottles are hard packaging containers with large volume and heavy weight. Tinplate has poor chemical corrosion resistance, especially when containing acidic food, metal ions are easy to precipitate, which affects the flavor of food.

In 1960s, the United States invented the aluminum-plastic composite film, which solved the packaging problem of space food. Can be used for packaging meat products, can be preserved at room temperature through high-temperature and high-pressure sterilization, and has a shelf life exceeding 1 year. The function of aluminum-plastic composite film is similar to that of can, which is soft and light, hence the name soft can. At present, tinplate cans, glass bottles and other meat products with long shelf life are still used at room temperature, such as hard packaging containers; If soft packaging is used, almost all aluminum-plastic composite films are used.

Aluminum-plastic composite film is a kind of laminated composite multilayer film, generally with three layers, and its typical structure is surface layer/adhesive/aluminum foil/adhesive/heat seal layer (CPP). The packaging film has the advantages of beautiful appearance, good mechanical properties, high barrier performance, high temperature cooking resistance, good hygiene, light weight and softness, and is widely used in the packaging of various foods. However, there are also some defects, such as the hard and brittle texture of aluminum foil and its softness is not good compared with that of plastic film.

In order to prolong the shelf life of meat products, meat products that can withstand high-temperature cooking are vacuum-packed and shaped. When aluminum foil composite material is vacuumized, it is difficult to completely stick to the contents due to the lack of flexibility of aluminum foil, which may easily lead to the air in the packaging bag not being cleaned and affect the preservation of food. Therefore, the thickness of aluminum foil used for meat packaging should not be too high. However, because its barrier performance depends on the thickness and processing level, a large number of pinholes are easy to appear when the thickness is small, so the thickness of aluminum foil used for storage-resistant meat food packaging should not be too thin; If the aluminum foil is too thin, the aluminum foil composite film will form many folds after vacuum pumping, which is easy to produce cracks and cause the loss of barrier property. Therefore, the thickness, barrier and flexibility of aluminum foil have always been three major contradictions that plague the application of aluminum foil composite film.