High-temperature retort pouches are packaging containers made of composite plastic films, combining the high sealing properties of canned goods with the portability of plastic bags. They allow food to be sterilized at 120-135℃ and then stored at room temperature, preserving the flavor and nutrients of meat, soy products, and other foods. Their multi-layered structure typically includes a polyester or nylon outer layer, an aluminum foil barrier layer, and a polypropylene heat-sealing layer; a typical combination is PET/AL/CPP. This technology originated from aluminum-plastic composite films developed in the United States in the 1960s, initially used for space food packaging, later known as "flexible cans."
In the 1990s, breakthroughs in PVDC film technology allowed for the creation of transparent laminated films through solvent-free lamination, improving barrier properties and microwave resistance. In the 21st century, polyvinyl alcohol (PVA) coating materials have expanded their applications, also possessing biodegradable properties. Manufacturing primarily uses dry lamination, requiring precise control of parameters such as coating amount and curing temperature to ensure no delamination or leakage after retort. Product testing covers indicators such as composite strength, residual solvents, and pressure resistance sealing, meeting the packaging requirements of food, pharmaceuticals, and other industries.
