Case Study: Oxygen Barrier Properties of Recycled PET Bottles

JINAN, China - Aug. 26, 2025 - PRLog -- Recycling plastic bottles is vital for environmental protection, but it can affect their oxygen barrier properties, making them less suitable for oxygen-sensitive products. Our case study on PET bottles with varying amounts of recycled material found that increasing the recycled content from 25% to 50% only slightly reduced their oxygen barrier. This suggests that using more recycled material does not significantly compromise the bottles' performance.

The Test

Two types of PET bottle samples were tested: one containing 25% recycled material and another with 50% recycled material. The testing was conducted using the coulometric method, a standard approach for measuring the oxygen transmission rate (OTR) of packaging materials, as outlined in standards such as ASTM F1307-02. The test conditions were set at a temperature of 23∘C and a relative humidity of 100% RH to simulate the environment of liquid-filled bottles. The samples were meticulously sealed onto a special container-supporter to prevent leakage, then placed in the test instrument for analysis.

The Instrument

The test was performed using Labthink C230H Oxygen Transmission Rate Tester (https://en.labthink.com/en-us/product/c230h-oxygen-transm...), which employs a coulometric sensor to measure OTR. This system is designed to test both film/sheet samples and container samples. Key features of the instrument include:

• High precision: A resolution of 0.001cm3/(m2⋅day) and a container sample test range of 0.00005−1cm3/(pkg⋅day).
• Automated control: The system automatically controls and monitors temperature and humidity within a range of 10−55∘C and 5−100% RH.
• Versatility: It can test up to three samples simultaneously and is compatible with a wide range of materials, including various plastic films, sheets, and containers like bottles and barrels.

The Results

The test yielded the following results for the oxygen transmission rates:

• 25% Recycled Material: 0.01792cm3/(pkg⋅day)
• 50% Recycled Material: 0.01907cm3/(pkg⋅day)

The findings showed that the OTRs for both samples were very similar, with the bottle containing 25% recycled material having a slightly better oxygen barrier property.

Conclusion

The study demonstrates that increasing the recycled content in PET bottles from 25% to 50% only slightly diminishes their oxygen barrier properties. The minimal difference suggests that recycled content, within this range, does not significantly compromise the bottles' ability to protect oxygen-sensitive products.This case study also serves as a testament to the effectiveness of Labthink C230H Oxygen Transmission Rate Test System. Its precise, automated, and easy-to-use nature makes it a reliable tool for manufacturers to ensure the quality and performance of packaging materials, supporting the broader goal of increasing sustainability in the industry.

As the demand for functional packaging materials grows, testing methods are evolving to ensure a more comprehensive evaluation of packaging films. Labthink encourages collaboration with packaging industry companies for quality control! Visit the website www.labthink.com to learn more!