packaging is the process that puts the product into bags, taking out of air inside the bag to achieve expected vacuum degree, then, finishing sealing.
The main function of vacuum sealer packaging is deoxygenation.
For example, it is useful to prevent food from spoilage. Its principle also is simple. Food metamorphism is mainly caused by the activity of microorganism, and most microorganisms (e.g., mold and yeast) needs oxygen to survive. Vacuum packing takes advantage of this principle, removing the oxygen in the packaging and inside the cell of food and making microorganism lose "survival environment". Experimental results show: when the concentration of oxygen in the packaging is 1% or less, the rates of microbial growth and reproduction fell sharply; when the oxygen concentration is 0.5% or less, most microbes will be reined in and stop breeding. (note: vacuum packing can’t inhibit anaerobic bacteria breeding and food metamorphism and discoloration cause by enzyme reaction, so it still need to combine with other auxiliary methods, such as cold storage, frozen, dehydrated, high temperature sterilization, irradiation sterilization, microwave sterilization, salt pickle, etc.)
In addition to inhibiting microbial growth and reproduction, another important function of vacuum deoxygenation is to prevent the food from oxidation., because the oil food contains a lot of unsaturated fatty acid, easy to be oxidized by the effect of oxygen, making food sour and degenerative. Moreover, the oxidation also makes vitamin A and C loss, volatile substances in food pigment by the role of oxygen, make the color darker. So oxygen can effectively prevent food from spoilage and maintain its color, aroma, taste and nutritional value.
Except for deoxygenation, the main function of packaging machine vacuum packing has the effects of compressive strength, air resistance, preservation. It can more effectively make food keep the original color, aroma, taste, shape, and nutritional value for a long time. In addition, there are many food not suitable for using vacuum packaging and vacuum and gas filled packaging must be used, Such as crisp fragile food, easily caked food, easily deformed oil food, and those food with sharp edges or their high hardness will puncture food packaging bags, etc. Food after vacuum and gas filled packaging, the air pressure inside packaging bags is greater than the atmospheric pressure outside packing bag. This can effectively prevent food from compression, broken or deformation, without affecting the packaging and printing appearance.