Principle and working mode of vacuum packaging machine

The main function of vacuum packaging is to remove oxygen, which is beneficial to prevent food spoilage. The principle is also relatively simple, because the deterioration of food mold is mainly caused by the activity of microorganisms, and the survival of most microorganisms (such as mold and yeast) requires oxygen. Vacuum packaging is the use of this principle to remove oxygen from the inside of the bag and food cells, so that the micro-objects lose their "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, salting System.

In addition to inhibiting the growth and reproduction of microorganisms, vacuum deoxidation is another important function to prevent food oxidation. 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, making the color darker. Therefore, oxygen scavenging can effectively prevent food from spoiling and maintain its color, aroma, taste and nutritional value.

The main function of vacuum air-packing is not only the anti-oxidation and quality-preserving functions of vacuum packaging, but also the functions of anti-pressure, gas-blocking and fresh-keeping. It can effectively maintain the original color, fragrance, taste and shape of food for a long time. 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 foods, easy to agglomerate foods, easy to deform and oily foods, foods with sharp edges or high hardness will pierce the bags. 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 of the packaging bag.

The vacuum inflated package is filled with nitrogen, carbon dioxide, oxygen single gas or a mixture of two or three gases after vacuum. 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.

Working mode of vacuum packaging machine:

The vacuum packaging machine is composed of a vacuum system, an inflation system, an electrical control system, and a pneumatic control system. There are 3 different working modes:

1. Vacuum mode: put the packaged item under the heating rod and put the suction nozzle into the bag → step on the foot switch → the heating rod slides under the action of the cylinder to the sponge strip to press the bag mouth → the bag mouth pauses → vacuum (As with the strapping machine, the vacuuming time can be preset according to the requirements) → The nozzle is retracted → The heating rod continues to slide down to press the bag mouth to heat, seal, cool → Finished product → The heating rod is restored to the highest position (the vacuum packaging machine is completed) a work cycle).

2, inflatable mode: put the package into the heating rod and put the suction nozzle into the bag → step on the foot switch → the heating rod slides under the action of the cylinder to the sponge strip to press the bag mouth → the mouth of the bag pauses → vacuum →Inflation→The nozzle is retracted under the action of the cylinder. The heating rod continues to slide down, heat, seal, cool→finished product→heating rod reset (vacuum packaging machine completes one working cycle).

3, sealing mode: (can be used as a general sealing machine) put the package under the heating rod → step on the foot switch → the heating rod slides under the action of the cylinder to the sponge strip to press the bag mouth, heating, sealing, cooling → Finished product → heating rod reset (complete a work cycle).