How to choose food packaging bags and their common sense Food packaging bags are generally used for packaging food, such as milk powder, tea, meat, snacks, beverages, milk, etc. Its material uses high-barrier plastic packaging material to achieve its shelf life. Fresh. Preserve flavor and extend shelf life. Good packaging materials have an important impact on food quality and safety, so how to choose food packaging bags, this article will analyze with you. At present, the widely used plastic packaging materials in the market are: 1. Polyethylene (PE) Polyethylene has low transparency, certain air permeability, tensile strength and tear strength, as well as certain flexibility and good moisture resistance. Good chemical stability, is a non-toxic packaging material. Therefore, it is often used in the heat sealing layer and moisture-proof coating of composite materials. 2. Polypropylene (PP) Polypropylene is polymerized from propylene, it is a very light plastic with good transparency and gloss, good physical and mechanical properties such as tensile strength, hardness and toughness, and good heat resistance , can be used continuously at a high temperature of 120 ° C, and can be cooked in boiling water. The chemical properties are stable, and it is stable to acids, alkalis, salts and many solvents within a certain temperature range. Hygienic and safe, meeting the requirements of food packaging. 3. Polyester (PET) is commonly known as polyester. High transparency and good gloss. It has excellent gas barrier, oil barrier and fragrance retention properties. Rigid and tough, high tensile strength. Good chemical stability, resistant to alkene acid and alkali. The temperature range used is wide, the normal operating temperature range is -70 ℃ ~ 120 ℃, and it can be used for a period of time at 150 ℃. Good hygiene and safety. It is widely used in poultry meat packaging. The composite film based on PET can be used for retort food packaging. 4. Polyamide (PA) is commonly known as nylon, which has strong gas barrier properties, but has poor barrier properties to water vapor, strong water absorption, and swells with the increase of water absorption, resulting in a sharp decline in gas barrier and moisture barrier properties. Its strength and package dimensional stability are also affected. It has good mechanical properties, good toughness and wear resistance, cold resistance and heat resistance. It has stable chemical properties, good printability and good puncture resistance. The material meets the requirements for hygienic safety of food packaging. Therefore, it is widely used in frozen packaging and retort packaging of food. Because of its good printability and puncture resistance, most of the refined rice sold in the market now use nylon packaging bags. The above four materials are often used for packaging in the field of food packaging. We also know that the materials selected for food packaging must have appropriate barrier properties. For example, oily food requires high oxygen and oil resistance; dry food requires high moisture barrier; aromatic food High resistance to peculiar smell is required; while fruit and vegetable fresh food requires certain oxygen, carbon dioxide and water vapor permeability; at the same time, it must have good physical and mechanical properties, mainly including the tensile strength of the material, tearing Strength, impact strength, etc.; also have good chemical stability, and should not have any chemical reaction with the food inside to ensure food safety. It also has high temperature resistance, which is suitable for high temperature disinfection and low temperature storage of food. Therefore, most of the food packaging on the market is mainly composed of composite plastic film packaging, especially high-barrier materials have become the main body of food packaging. Therefore, the requirements for the quality, freshness and flavor preservation of the contents should be considered first when selecting. At the same time, when choosing plastic bags, we must fully understand the relevant properties of plastics and choose them reasonably. Special attention should be paid to the fact that plastic films (bags) used for food packaging must meet the hygienic standards for plastic moldings of the corresponding materials. That is to say, all raw materials of food packaging bags must be food grade before they can be put into use. Our company specializes in the production of food aluminum foil bags, food vacuum packaging bags, food vacuum bags, food zipper bags and other products.