Why are chips packaged in bags? Because the fried chips are brittle, they are easy to oxidize and become soft when in contact with air, and after being packed into the bag, the air can be well isolated and the shelf life of the chips can be extended.
The material of the chips bag:
Generally, the packaging material used for chips products is a composite film packaging bag, which is a combination of printing layer/aluminized barrier layer/heat sealing layer. It can be seen that the aluminum layer is not in direct contact with the food, usually it is in direct contact with some safer materials. Common composite methods are as follows.
- KOPP/VMOPP/LDPE：
It has good heat sealing performance, oxygen resistance and light shading, and the shelf life can reach more than one year. If the method of nitrogen filling is used, it can also achieve a longer shelf life.
- BOPP/VMPET/CPP (or PE), BOPP/PE/VMPET/CPP co-extrusion film, OPP/PET/AL/CPP:
The form used is modified atmosphere packaging, which has the advantages of sealing, light-shielding, oil resistance and so on.
- BOPP/VMCPP、PET/VMCPP：
Compared with the above two materials, the cost is lower, but the shelf life is slightly shorter. The material can resist oxygen, moisture, light, oil, bright colors and low cost. Among them, BOPP, PET and VMCPP have better stiffness, BOPP has good printability and high gloss. VMCPP has good barrier properties, and CPP has good oil resistance.
Bag flushed with nitrogen
We know that the deterioration of food is due to contact with oxygen in the air, and oxygen can accelerate the oxidation process of food and promote the life activities of microorganisms, resulting in bacteria and food deterioration.
Nitrogen is chemically inert and is often used as a shielding gas. After filling with nitrogen, the packaging can effectively remove oxygen, thereby inhibiting the oxidation of food and the reproduction of microorganisms.
In addition, nitrogen filling can also resist the intrusion of external moisture. The positive pressure environment created by the nitrogen-filled packaging can prevent the food inside from getting wet and ensure the freshness of the food.