Vacuum machine is one of the mechanical equipment commonly used in the packaging industry. The vacuum machine is generally composed of a vacuum chamber, a vacuum pump, a mouth strip, a plexiglass plate cover, an air bag, a solenoid valve, and the like. The vacuum packaging is to put the food into the packaging bag, and to extract the gas in the packaging bag, and after completing the predetermined vacuum degree, the sealing and embossing date process is completed once. The vacuum inflated package puts the food into the packaging bag, and after the air in the packaging bag reaches a predetermined vacuum degree, it is filled with nitrogen or other mixed gas, and finally, the sealing and imprinting date process is completed once. The products are filled with gas, (expanded food, bread, fish fillets, etc.). There are also some conditions for the protection of pressure, shatterproof, gas barrier, fresh-keeping, and keeping food dry.
The working principle of empty machine: The main function of vacuum packaging is to remove various gases in oxygen and air to help prevent food spoilage. The principle is also simple, because the deterioration of food mold is mainly caused by the activity of microorganisms, and most microorganisms The survival of (such as mold and yeast) requires oxygen, and vacuum packaging uses this principle to remove oxygen from the inside of the package and food cells, so that the micro-objects lose the "living environment." The experiment proves that when the oxygen concentration in the package is ≤1%, the growth and reproduction speed of microorganisms will drop sharply. When the oxygen concentration is ≤0.5%, most microorganisms will be inhibited and stop breeding. (Note: Vacuum packaging can not inhibit the deterioration and discoloration of food caused by anaerobic bacteria reproduction and enzyme reaction, so it must be combined with other auxiliary methods, such as refrigeration, quick freezing, dehydration, high temperature sterilization, irradiation sterilization, microwave sterilization, salt Pickled, etc.)
In addition to inhibiting the growth and reproduction of microorganisms, vacuum deoxygenation is another important function to prevent oxidation of foods. Because oils and fats contain a large amount of unsaturated fatty acids, they are oxidized by the action of oxygen, which makes foods taste and deteriorate. In addition, oxidation also makes Loss of vitamins A and C, unstable substances in food pigments are affected by oxygen, which makes the color darker. Therefore, oxygen scavenging can effectively prevent food from spoiling and maintain its color, aroma, taste and nutritional value. Has great commercial value.
The main function of vacuum air-packing, in addition to vacuum packaging, has the functions of deoxidizing, preserving and preserving, mainly anti-pressure, shatterproof, gas-blocking and fresh-keeping, which can effectively maintain the original color of food for a long time. Fragrance, taste, shape and nutritional value. In addition, there are many foods that are not suitable for vacuum packaging and must be vacuum-filled. Such as crispy and fragile food, easy to agglomerate food, easy to deform and oily food, food with sharp edges or high hardness will pierce the bag. After the food is vacuum-insulated, the inflation pressure in the packaging bag is stronger than the atmospheric pressure outside the packaging bag, which can effectively prevent the food from being crushed and deformed without affecting the appearance and printing decoration of the packaging bag.
The vacuum-inflated package is vacuum-filled with a single gas of nitrogen, carbon dioxide, oxygen, or a mixture of two or three gases. The nitrogen gas is an inert gas, which acts as a filling to maintain a positive pressure inside the bag to prevent the air outside the bag from entering the bag, thereby protecting the food. Its carbon dioxide is soluble in various types of fat or water, and it is classified into weakly acidic carbonic acid, and has the activity of inhibiting microorganisms such as mold and spoilage bacteria. Its oxygen inhibits the growth and reproduction of anaerobic bacteria, keeps the freshness and color of fruits and vegetables, and high-concentration oxygen keeps fresh meats bright red.