Meat consumption is a key indicator of a nation's standard of living. Since the reforms and opening-up, policy adjustments have spurred rapid development in the agricultural economy. For twenty-five consecutive years, China has witnessed sustained growth in meat production.

Meat processing comprises two main segments: the processing of fresh meat cuts and the production of prepared meat products, encompassing thousands of commodity types. Fresh meat products are primarily categorized as hot meat, frozen meat, and chilled meat.

• Hot meat, consumed soon after slaughter, has a tough texture and spoils easily if stored.

• Frozen meat often suffers from ice crystals piercing cell membranes during freezing, leading to juice loss and poor texture upon thawing.

• Chilled meat requires the carcass temperature to be consistently reduced and maintained between 0°C and 4°C.

Through segmentation and packaging, this temperature is strictly controlled from production to sale. This inhibits microbial growth and enzyme activity, thereby preserving and enhancing the meat's quality and flavor.

The primary purpose of flexible plastic packaging in meat production is to ensure food safety and hygiene. Packaging materials with different properties meet the varied requirements for processing, storage, and transportation of different meat products.

Three other types of artificial casings—nylon casings, cellulose casings, and collagen casings—are widely used in low-temperature sausage production.

• Nylon casings offer excellent oxygen barrier properties and are shrinkable. They can withstand steaming at 120°C for up to two hours and are commonly adopted by small and medium-sized manufacturers.

• Cellulose casings have good breathability, allowing products to be smoked. Small-diameter casings (Φ17–Φ50) are used for peelable sausages, while large-diameter casings (Φ85–Φ150) are used for Western-style hams. China primarily relies on imports for cellulose casings, with an annual consumption of approximately 3 million meters.

• Collagen casings are edible casings produced from collagen fibers extracted from bovine hide. Their composition is similar to natural hog and sheep casings, but they offer superior uniformity and compatibility with highly automated sausage fillers, making them the preferred choice for most large and medium-sized meat producers.

Collagen casings, mainly in specifications like 伞13-中30, currently have an annual usage in China of about 400 million meters. Domestic production comes from facilities like the Guangxi Wuzhou Casing Factory, with an annual output exceeding 250 million meters. The remainder is imported. It is projected that China's demand for collagen casings will reach around 800 million meters by 2010.