Vacuum bag is made of plastic film, it is composed of two parts. Usually we refer to this part of the bag. It is a material used to protect the quality of a product. At present, there are two kinds of vacuum packaging bags commonly used in the market: plastic film and aluminum foil. Of these two materials, aluminum foil bags are often referred to as composite aluminum foil bags. Compared with ordinary plastic materials, it has many advantages. It is manifested in the following aspects:
First, it has strong resistance to oxygen and enzymes
This is mainly due to a special coating on the surface of the foil bag. The main function of this coating is to prevent the effects of oxygen and enzyme activity of the packaging material. If moisture is present, the coating keeps oxygen and enzymes out of the packaging, extending the product's shelf life.
All three materials have strong antioxidant capacity. Although they are highly antioxidant, they have little resistance to oxygen and enzymes. Therefore, aluminum foil bag is widely used in food packaging, in order to achieve the purpose of preservation.
Two, good barrier to carbon dioxide and water vapor
The gas transmittance of vacuum bag can be expressed by using different types of gas transmittance. Compared with other packaging materials, vacuum packaging bags have strong gas permeability, so it can prevent the air inside the product. In order to further improve its gas permeability, it is usually necessary to apply it to various gases. For example, it prevents oxygen from the air from entering the food when it enters the vacuum bag, and water vapor from the food from entering the vacuum bag. In addition, it is necessary to improve the permeability of gas by selecting different types.
Three, good heat sealing
The heat sealing property of the vacuum bag is also very good. Because the vacuum bag adopts aluminum foil packaging, it can play a certain protective role in the sealing process, so as to achieve the thermal sealing effect of the vacuum bag. Compared to other plastic materials, aluminum foil is a very good heat sealing material. Aluminum foil itself has good resistance to high temperature and chemical corrosion, so it has good heat sealing performance.
When the vacuum bag is vacuumed, it can prevent food from oxidation and spoilage to a great extent. In addition, the vacuum bag can also prevent food odor, and has certain moisture-proof and fresh-keeping function. Also, since it is made of aluminum foil, no chemicals need to be added when it is packaged, so it has good environmental performance.
Four, high intensity
Vacuum packing bag is a kind of packing material with high mechanical strength, which has obvious advantages compared with ordinary packing materials. For example, it can withstand greater pressure. For ordinary plastic film and aluminum foil bags, they can only withstand a certain amount of pressure, but not more. In addition, ordinary plastic sheeting and aluminum foil bags are only suitable for food protection, not for other items.
After knowing the advantages of vacuum packaging bag, we can also find that vacuum packaging bag is a very effective fresh-keeping packaging technology. In addition to the above introduction, it also has good barrier performance and heat sealing. Therefore, as long as the vacuum bag is used in combination with other packaging materials, the shelf life of products can be extended. Therefore, we should make full use of vacuum packing bag, a new packaging technology, to protect food safety and extend the shelf life.
