Recycling processes， industrial applications， and identification characteristics of recycled polyester

doi:10.19491/j.issn.1001-9278.2025.06.014

Abstract

Abstract:

This paper reviewed recycling methods for polyethylene terephthalate （PET） waste， covering both physical and chemical regeneration processes. The applications of recycled PET （rPET） in sectors such as textiles and food packaging were summarized， emphasizing its versatility across industries and significant market potential. The review also delineated structural and performance differences between PET and rPET， and elaborates on identification methods that leverage these distinctions through advanced chemometric techniques and machine learning models， as investigated in domestic and international research. Finally， future studies should prioritize cost reduction in chemical regeneration processes， development of higher⁃value⁃added rPET products， and the establishment of rapid， reliable identification protocols to enhance quality control and sustainability efforts.

Key words: recycled, polyethylene terephthalate, spectroscopy, regeneration processes, identification methods, machine learning

CLC Number:

TQ323.4

LI Zeyang, LIU Shu, YAN Chenglin, SUN Jie, TANG Lei, WEI Mengjuan. Recycling processes， industrial applications， and identification characteristics of recycled polyester[J]. China Plastics, 2025, 39(6): 73-83.

Figures/Tables 17

Fig.1. Waste polyester recycling engineering technology

Fig.2. Process flow of PET bottle flakes by physical method ［13］

Fig.3. Major chemical reactions in PET recycling

Fig.4. Mechanism of PET hydrolysis reaction in sulfuric acid solvent ［13］

Fig.5. Reaction mechanism of PET alkaline hydrolysis ［13］

Fig.6. Photocatalytic depolymerization of PET ［21］

Fig.7. Neutral hydrolysis of PET ［22］

Fig.8. Mechanism of PET alcoholysis reaction in alcohol solvent［33］

Fig.9. Mechanism of PET alcoholysis reaction in methanol solvent［33］

Fig.10. Dimethyl carbonate⁃assisted methanolysis of polyester textiles ［31］

Fig.11. PET glycolysis mechanism ［8］

Fig.12. PET ammonolysis mechanism ［37］

Fig.13. Annual market size of rPET globally segmented by final use in 2016 ［8］

Fig.14. Polyester fiber produced by jiaren chemical method

Fig.15. TOMRA automatic sorting equipment

Fig.16. Food⁃grade super⁃clean secycled polyester chips

Fig.17. Acoustic panels and construction plywood made from rPET

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