PP/EVOH/PP high barrier plastic sheet application case

With the continuous advancement of food packaging technology, high barrier materials play an important role in extending the shelf life of food and improving packaging quality. In the food industry, the use of high barrier materials to prevent external factors such as oxygen and water vapor from entering the packaging, thereby maintaining the freshness of food, has become an inevitable choice. As an excellent barrier material, PP/EVOH/PP high barrier plastic sheet is widely used in the thermoforming processing of food packaging trays, ensuring the safety and freshness of food during storage and transportation.

Case Background

In this project, a large food processing plant wanted to develop a packaging tray that could extend the shelf life of food and keep it fresh for packaging refrigerated meat and ready-to-eat meals. They required the tray to have good gas barrier properties, high strength and thermoforming capabilities to achieve efficient packaging on the production line. The project also required the food packaging to have a beautiful appearance, no odor, and good transparency to enhance the shelf appeal of the product.

Project Challenges

Balance of Barrier and Formability

In the design, it is a challenge to ensure that the packaging material has both excellent barrier properties and good thermoforming properties.

Although EVOH has excellent barrier properties, its mechanical strength is relatively low, and it needs to be reasonably compounded with the PP layer to ensure that the material can maintain high barrier properties while still meeting the high requirements of the production line for thermoforming performance.

High transparency requirements

The customer hopes that the packaging tray can maintain good transparency so that consumers can clearly see the food in the package. This requires optimizing the transparency of the material on the basis of ensuring the barrier properties of the material.

Economical mass production

Due to the large demand of food processing plants, how to control material costs and achieve large-scale mass production while ensuring performance is a major challenge in the project.

Solution

Through in-depth communication with customers and multiple sample tests, we finally chose PP/EVOH/PP high barrier sheet. The composite structure of the material ensures that the food packaging tray has both excellent barrier properties and excellent performance in the thermoforming process. At the same time, we adjusted the material transparency to meet the customer’s high requirements for packaging appearance.

During the production process, we optimized the thermoforming process to ensure that each tray has accurate dimensions and tight sealing, and can run stably in an efficient assembly line. In addition, the lightweight design of PP/EVOH/PP materials helps customers save transportation and storage costs.

PP/EVOH/PP high barrier plastic sheet is a multi-layer co-extruded film consisting of two layers of polypropylene (PP) and a middle layer of ethylene vinyl alcohol copolymer (EVOH).

High barrier performance: The EVOH layer can effectively block oxygen, water vapor, grease, etc., extend the shelf life of food, and maintain the freshness and flavor of food.
High temperature resistance: PP material has good heat resistance and can withstand high temperature sterilization process.
Chemical resistance: PP and EVOH have good corrosion resistance to chemicals such as acids, alkalis, greases and oils.
Food grade safety: The material meets food grade standards, is non-toxic and odorless, and can directly contact food.
Thermoformable: It can be processed into packaging containers of various shapes through thermoforming process.

Customer evaluation

After the project was completed, the customer gave high praise to the PP/EVOH/PP high barrier sheet packaging tray we provided. They especially appreciated the high transparency and excellent gas barrier properties of the tray, which significantly extended the shelf life of refrigerated meat products and reduced returns and losses due to food spoilage. In addition, the customer mentioned that the tray molding effect is good in large-scale production, which can keep the production line running efficiently.

Conclusion

PP/EVOH/PP high barrier plastic sheet provides an ideal solution for the food packaging industry, especially in application scenarios where the shelf life needs to be extended. It combines the mechanical properties of PP and the high barrier properties of EVOH, which not only ensures the freshness and safety of food, but also has excellent molding and processing performance, meeting customers’ multiple needs for packaging appearance, cost control and environmental protection. Through the successful implementation of this project, the advantages of PP/EVOH/PP sheet have been fully demonstrated.