1. Mechanical properties: It is necessary to ensure the smooth operation of food in various links such as processing, transportation, storage, supply and sales. If the mechanical performance indicators of the product do not meet the requirements, it is easy to affect the strength of the product, causing the product to break easily during use. If damage occurs, it is easy to cause the loss, deterioration, deterioration and contamination of the packaging.

2. Barrier property: refers to the barrier ability of film (bag) to oxygen, water vapor, etc. Testing it can be used to guide the raw materials and product structure of food packaging film (bag), and lay the foundation for determining its shelf life. Different types of food have different barrier properties. Oily foods have higher oxygen and oil barrier properties; dry foods have higher moisture resistance; fragrant foods have higher odor resistance requirements; fresh fruits and vegetables also need a certain amount of oxygen, carbon dioxide and water vapor.

3. Biosafety:Plastic packaging bags for foodWhether it is contaminated by bacteria, mold and other microorganisms is related to the storage environment. For example, a storage environment with high humidity may grow a lot of mold, and the material will also mold. If the packaging material contains microorganisms, it will cause certain harm to the food.

4. Chemical safety: It is an important indicator that has a significant impact on food safety. It mainly comes from heavy metals contained in plastic films (bags) used for food, impure monomer raw materials, organic compounds that are toxic to the human body or residual accumulation, etc. The second is toxic and harmful substances produced during the production process, such as solvent residues mainly composed of benzene; secondly, during the storage and use of food packaging, food deterioration caused by improper packaging design, and the migration of organic matter in the packaging material causes pollution to the food in the package.

With the increasing requirements for plastic bags for food, companies, while considering their chemical and biological safety, ignore the degradation of their mechanical and barrier properties.