Reusing PET Plastic Containers: What You Need to Know

PET plastic containers, such as storage boxes, are favored for their superior transparency, strength, chemical resistance, and outstanding gas and moisture barrier properties. These qualities make them a safe and convenient choice for storage in various settings, including homes, offices, and warehouses.

PET Plastic Containers vs. Other Plastic

Compared to other commonly used materials for plastic storage containers, PET plastic offers notable advantages. 

Firstly, PET plastic boasts a transparency of over 90%, surpassing PP (polypropylene) and PE (polyethylene), which allows for clear visibility of the contents inside the container.

PET plastic also exhibits higher impact resistance compared to PE and PP. For instance, PET's impact strength ranges from 4-6 kJ/m², compared to PE's 2-4 kJ/m² and PP's 2-3 kJ/m². This enhanced impact resistance makes PET containers less likely to deform or break under heavy loads or collisions, providing superior protection for stored items.

Additionally, PET has better gas and moisture barrier properties than PP and PE, effectively preventing items from becoming damp or oxidized. PET's water vapor transmission rate (WVTR) is as low as 0.5-1 g/m²·24h, making it ideal for long-term storage of items that need to remain dry.

Compared to PVC and PS, PET has higher chemical resistance, withstanding corrosion from acids, bases, and oils, making PET containers suitable for storing items with chemical substances.

Although PET's high-temperature resistance is not as strong as PC (polycarbonate), it performs better at low temperatures, making it suitable for refrigeration or freezing environments. 

Moreover, PET's recycling system is more developed than that of other plastics, with a recycling rate of approximately 30%-40%, enhancing its environmental benefits and ensuring no harmful substances are released during the recycling process.

Example of High-Quality PET Resin: WK-781 by Wankai

Wankai New Materials Co., Ltd.'s PET resin WK-781 is a high-performance material specifically designed for producing thick-walled transparent plastic boxes. WK-781 is suitable for direct injection molding and is widely used in manufacturing cosmetic bottles, wine boxes, storage boxes, refrigerator drawers, and more. This material meets international standards for heavy metals and acetaldehyde content, ensuring product safety. During processing, WK-781 demonstrates excellent flowability and production stability, resulting in products with both high transparency and exceptional strength.

Reusing PET Plastic Containers: Best Practices and Limitations

Reusing PET plastic containers is an eco-friendly and cost-effective practice. Many people keep and repurpose plastic containers such as bowls, storage bins, and bottles, benefiting from PET's moisture resistance, transparency, and safety features. PET containers are ideal for storing dry goods like grains and nuts, beverages like water and juice, as well as office supplies, buttons, cleaning products, cosmetics, tools, clothing, toys, and important documents. They effectively keep items dry and fresh while maintaining organization. However, not all items are suitable for storage in plastic containers.

Leather: According to Tom’s Guide, although PET containers have good moisture resistance, it is not recommended to store leather in plastic bins. Long-term storage of moisture-absorbing items like leather can lead to issues with accumulated humidity inside the container, causing leather to crack or develop mold. For other clothing items, it is advisable to ensure they are dry before storage and to use dedicated moisture control measures.

Electronic Devices: It is recommended to store old electronic devices and batteries in anti-static packaging and place them in a well-ventilated environment. Plastic containers can generate static electricity, which may damage sensitive electronics and potentially cause battery leaks. Using anti-static packaging provides better protection for these devices and batteries.

Hot and Greasy Foods: Southern Living suggests storing greasy foods in glass containers rather than plastic ones because high oil content can break down plastic and contaminate food. For hot foods, the publication notes: "Hot foods and liquids should never be placed directly into plastic containers as high temperatures can cause plastics to release harmful chemicals. Allow food to cool before using plastic containers."

Perishable Fruits: Southern Living also advises against storing perishable fruits like citrus fruits, avocados, and berries in plastic containers. The lack of breathability in sealed plastic containers can cause fruits to soften and mold.

Longevity and Care for Reused PET Plastic Containers

When storing suitable items in PET plastic containers, it’s important to consider the lifespan of the PET material. Although PET is commonly used for single-use food and beverage packaging, it can be safely reused under the right conditions.

For food storage, it is recommended to limit the reuse of PET containers to a few times and ensure that each use involves thorough cleaning and inspection. For non-food items, PET containers can last longer as long as they are maintained in good condition.

Specially designed PET containers for storage and organization typically have a longer lifespan compared to PET containers used for food and beverage packaging. Since these storage containers are less frequently exposed to high temperatures, acidic substances, or oils, they degrade more slowly. In household or office settings for general storage purposes, PET containers can last between 5 to 10 years or even longer, provided there is no visible physical damage or material degradation. Nonetheless, regular inspection of the containers is necessary, and they should be kept away from extreme environmental conditions.

Conclusion

PET plastic containers are highly effective for various storage needs due to their transparency, strength, chemical resistance, and barrier properties. They are ideal for dry goods and non-perishable items but less suitable for high-moisture or high-temperature applications, sensitive electronics, and perishable fruits. By adhering to proper usage and care, PET containers can be safely reused, offering cost savings and environmental benefits while extending their lifespan.