Introduction
The national standard GB/T 39026-2020 “Identification Method for Recycled Polyester (PET) Fiber” implemented on February 1, 2021 has filled in the The domestic and foreign gaps in this field provide technical support and guarantee for the country to formulate relevant policies.
1. Overview of recycled polyester (PET)
Waste polyester Polyethylene terephthalate fiber is made by recycling ester (PET) polymer and waste polyester (PET) textile materials.
In layman’s terms, recycled polyester fiber (hereinafter referred to as recycled polyester) refers to the use of waste polyester (such as bottle flakes, foam, waste silk, waste pulp, waste textiles etc.) are recycled polyester fibers made through a regeneration process.
2. Identification Principle
Processed from recycled polyester and virgin polyester Based on the essential difference in the process, some characteristics are different. After the sample is processed according to the specified conditions, it is detected on a high-performance liquid chromatograph. Based on the difference in relative peak area under different retention times of the sample, the purpose of qualitative identification is achieved.
3. Identification steps
1. Methanol alcoholysis
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2. Swelling-Extraction
3. High-performance liquid chromatography detection
The treated liquids processed in the above 1 and 2 will be subjected to high-performance liquid chromatography detection.
4. Data processing and identification
Regenerated polyester in the preparation process It will cause changes in the content and distribution of macromolecule heterogeneous links and oligomers, which can be used as a basis for the identification of recycled polyester and virgin polyester.
The specific positioning peaks and characteristic peak information are shown in the table below.
Four. Looking to the future
With the increase in polyester consumption With the increase in environmental awareness and the enhancement of people’s environmental awareness, polyester waste recycling has attracted more and more attention. Using polyester waste to produce recycled polyester fiber can reduce costs, reduce oil consumption, and improve economic benefits, which is of great significance to the sustainable development of the chemical fiber industry.
At the same time, with the increase in the use of recycled polyester, the substitution issue of recycled polyester and virgin polyester has attracted more and more attention in the industry, and the price trends of the two have also shown There is a certain positive correlation, and the detection technology to distinguish the two has attracted more and more attention. </p
