How to Distinguish Recycled Polyester(rPET) ?

In industries such as textiles, plastics, and packaging, environmentally advantageous recycled polyester (rPET) is gradually replacing organic PET.

Most polyester (PET) products are disposable consumer goods, such as PET plastic bottles. These discarded PET products do not easily degrade in the environment over a short period of time, and due to their extensive usage, they can cause serious pollution to the environment.

Recycled polyester is a prime example of the green and environmentally friendly circular economy industry, offering significant advantages in energy conservation and environmental protection. In industries such as textiles, plastics, and packaging, environmentally advantageous recycled polyester (rPET) is gradually replacing organic PET.

So, what exactly is Recycled Polyester (rPET)? rPET refers to polyester fiber made from recycled materials such as bottle flakes, foam materials, waste threads, waste pulp, and old textiles through a recycling process. It is commonly known as recycled polyester.

rPET’s raw materials primarily come from two sources. The first source is waste and off-cuts generated during production and processing, which are relatively clean and can be directly utilized. The second source is discarded PET packaging, such as PET plastic bottles. These materials often contain pollutants and must undergo separation to remove contaminants and additives before recycling.

There are two main processing techniques for recycled polyester fiber: physical and chemical methods.

The physical method primarily involves using waste PET bottles as raw materials. In this method, the waste PET materials, such as bottles, undergo processes like sorting, cleaning, and drying before being directly used as raw materials for melt spinning in the recycling process. This method offers advantages such as simple production technology, a relatively short process, and low production costs. However, it mainly allows for unidirectional recycling, and even the bottle-to-bottle recycling technology for food-grade bottles currently cannot achieve a completely closed-loop recycling of PET. As the processing cycles increase, the viscosity, molecular weight distribution, and impurity content of polyester fibers change continuously, making further recycling impossible. This type of rPET is commonly used in the manufacturing of non-apparel fabrics or home textiles, such as filling fibers, clothing linings, household textiles, strapping tapes, nonwoven fabrics, and industrial fabrics.

The chemical method primarily involves using waste threads or polyester components in clothing. In this method, chemical reactions are used to depolymerize waste PET materials into polymer monomers or intermediates, followed by purification and separation processes before undergoing recycling and melt spinning. Current chemical recycling technologies in the market include enzymatic hydrolysis, methanolysis, and alkaline hydrolysis. The chemical method enables complete recycling of discarded PET, with lower requirements for sorting and cleaning of waste PET. From a recycling perspective, the chemical method is more suitable for addressing clothing waste issues. The quality of rPET obtained through chemical recycling is not significantly different from organic polyester and can essentially replace virgin polyester in various applications.

As the market demands various functionalities of polyester products, the usage of multi-type polyester material is rapidly increasing. Physical recycling methods face challenges in recycling these products, whereas chemical recycling methods can address these technical difficulties.

To distinguish genuine and fake recycled polyester fiber (rPET), we can help identifying the authenticity of rPET which follows the principles outlined in GB/T 39026-2020 “Identification Methods for Recycled Polyester (PET) Fibers”, based on differences in the processing  and the content and distribution of large molecular heterogeneous segments and copolymers. PFI also offers an assessment service to determine the source of rPET materials derived from PET plastic bottles by measuring the isophthalic acid (IPA) content. This method is suitable for polyester materials produced from the recycling of PET plastic bottles.

Our clients can efficiently identify and control materials at any point in the supply chain, ensuring brand reputation and offering comprehensive solutions for a sustainable supply chain.

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