Views: 115 Author: Site Editor Publish Time: 2021-04-13 Origin: Site
Nowadays, as the pace of life changes, people's eating habits have also changed, and frozen foods that are easy to store are becoming more popular. The high demand of vacuum pack freezer bags on the market is due to the characteristics of long shelf life, low spoilage, and convenient eating of frozen food.
At present, the frozen food packaging bags on the market can be mainly divided into single-layer packaging bags, composite packaging bags, and multi-layer co-extrusion packaging bags. Among them, single-layer frozen food packaging bags, that is, pure PE bags, have poor barrier effect and are mostly used for fruit and vegetable packaging. Composite soft plastics are relatively good in terms of moisture resistance, cold resistance, and puncture resistance. In the production of multi-layer co-extruded frozen food packaging bags, PA, PE, PP, PET, EVOH and other raw materials with different functions are melted and extruded, and finally blown, molded, and composited by cooling. In terms of packaging performance, it has excellent characteristics such as pollution-free, high barrier, high strength, high and low temperature resistance.
Considering various factors, the most widely used of the three types of food grade freezer bags are composite soft plastics. And this kind of frozen food packaging bag also has many combinations in material structure:
1. PET/PE. This material structure is more common in the packaging of quick-frozen food products. The advantage is that it has good moisture resistance, cold resistance, low temperature heat sealability, and low production cost.
2. BOPP/PE and BOPP/CPP. The frozen food packaging bags of these two structures have excellent moisture resistance, cold resistance, and high tensile strength for low-temperature heat sealing.
3. PET/VMPET/CPE, BOPP/VMPET/CPE. The three-layer structure packaging bag is stronger and more stable than single-layer and double-layer, and has high barrier performance. The existence of aluminized layer also makes it have more prominent advantages in printing performance. However, compared with the above materials, the disadvantage is that the low-temperature heat sealing performance is slightly worse and the cost is higher.
4. PA/PE, PET/PA/LLDPE, PET/PA/AL/PE, PA/PE. These four types of material structures are more resistant to freezing and impact. The PA layer ensures good puncture resistance. The disadvantage is that the production cost is high, and it is generally used for the packaging of angular or heavier food products.
Generally speaking, the food freezer bags we are familiar with mainly include plastic freezer bags for meat, thick freezer bags and frozen food carrier bags.
When the easy-to-tear function of the frozen food grocery bags cannot be effectively exerted, the tearing strength is too large and the packaging bag is not easy to open, and the tearing strength is too small to reduce the mechanical properties of the packaging bag. Therefore, it is necessary to meet the humanized design of the easy-to-tear pork sausage freezer bags and leak proof freezer bags. At the same time, the protection of the product must be completed.
Good frozen food packaging must have high barrier properties, impact resistance and puncture resistance, low temperature resistance, oil resistance and hygiene.