Why has polyolefin film become the safety guard of food packaging? ​

As the core material in the field of food packaging, polyolefin film has built a solid line of defense for food safety with its performance. Polyolefin polymers represented by polyethylene (PE) and polypropylene (PP) are naturally safe for direct contact with food due to their stable chemical structure and regular molecular chains, making them an ideal choice for food packaging materials. ​

The hygienic properties of polyolefin film come from its pure chemical composition. Its polymerization process uses highly purified monomer raw materials, and through a controllable polymerization process, it minimizes residual monomers and catalyst impurities. During the molding process, the polyolefin molecular chain forms a dense structure through physical entanglement and crystallization. This structural characteristic makes its surface smooth and flat, making it difficult for microorganisms and impurities to attach. At the same time, the polyolefin molecular chain lacks active groups that can react chemically with food. During long-term contact with food ingredients such as oil, water, etc., it can still maintain chemical inertness and prevent harmful substances from migrating into food, thereby meeting the strict hygiene requirements of food packaging. ​

In terms of isolating the external environment, polyolefin film exhibits barrier properties. Its tight molecular arrangement effectively blocks oxygen penetration, inhibits oil oxidation and microbial respiration in food, and slows down the rate of food spoilage. For water vapor barrier, the non-polar molecular structure of polyolefin film makes it difficult to be compatible with water molecules, which can prevent food from softening and mildewing due to moisture absorption, and maintain the taste and quality of food. For microbial invasion, the low surface energy characteristics of the film surface hinder the attachment and growth of microorganisms such as bacteria and molds, while its complete physical barrier isolates microorganisms from the outside of food, further extending the shelf life of food. ​

In the process of food packaging, the processing adaptability of polyolefin film is also critical. Through molding processes such as blow molding and cast film, the thickness, transparency and mechanical strength of the film can be precisely controlled to meet the needs of different food packaging. For example, high-transparency film is suitable for display food packaging, while high-strength film can withstand the storage and transportation pressure of frozen food. At the same time, the good heat sealing performance of polyolefin film enables it to form a firm sealing structure during the packaging process, ensuring the integrity of the packaging and further enhancing its barrier properties. ​

To ensure the safety of polyolefin film in food packaging, the production process must strictly follow international and national standards. From raw material screening, production process control to finished product testing, every link needs to be strictly controlled. On the raw material side, it is necessary to ensure that polyolefin resins pass the food contact material safety certification; in the production process, it is necessary to avoid improper use of additives to prevent migration risks; in the finished product stage, the physical properties, chemical stability and microbiological indicators of the film need to be fully tested to ensure that it meets the hygiene standards of food packaging materials. ​

Polyolefin film has established a reliable safety guarantee system in the field of food packaging with its stable chemical structure, barrier properties and strict production standards. With the continuous improvement of the food industry's requirements for packaging safety and functionality, polyolefin film will also continue to be optimized and upgraded, while ensuring food safety, providing strong support for the innovative development of the food packaging industry.