Vacuum, the term translated from the Latin vacuo, means nothingness. In fact, a vacuum should be understood as a space where the gas is thinner. In a given space, the state of a gas below one atmospheric pressure is collectively referred to as a vacuum. The degree of gas thinning in the vacuum state is called the degree of vacuum (degree ofvacuum), which is usually expressed by the pressure value. Therefore, vacuum packaging is actually not completely vacuum, and the vacuum in food containers packaged by vacuum packaging technology is usually 600-1333Pa. Therefore, vacuum packaging is also called decompression packaging or exhaust packaging.
Vacuum packaging technology originated in the 1940 s. In 1950, polyester and polyethylene plastic films were successfully used for vacuum packaging, and since then, vacuum packaging has developed rapidly.
China's vacuum packaging technology was developed in the early 1980 s, while vacuum inflatable packaging technology began to be used in small quantities in the early 1990 s. With the promotion and development of small packaging, its scope of application is becoming more and more extensive. Some will gradually replace hard packaging, and the prospect is very promising.
From the 1950 s to the mid -1980 s, di was a development period, which began with the manufacture of simple air pumps. At that time, there were less than 20 enterprises producing vacuum equipment in the country, and the products were mainly medium and low-grade vacuum acquisition equipment, such as mirror coating machine cigarette packaging machine. From the late 1980 s to the entire 1990 s was the second period of the development of China's vacuum industry. During this period, the number of production enterprises increased to nearly 3000, with 35000 employees. The whole vacuum industry after the "seven five", "eight five" after the technical transformation of the overall level has been greatly improved, from the processing conditions, processing center CNC machine tools, resin sand castings and other production equipment began to equip enterprises. By 1996, due to the pull of magnesium smelting industry, the vacuum industry has developed rapidly.
