Study on the identification method of the hottest

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Research on identification methods of recycled plastics

plastics are important materials for preparing drug packaging containers, and are widely used in the drug packaging industry. Common drug packaging products, such as polypropylene and polyethylene infusion bottles with excessive oil spillage, non PVC multi-layer coextrusion infusion bags, oral solid pharmaceutical polypropylene bottles, oral solid pharmaceutical high-density polyethylene bottles, are made of plastic materials. In order to ensure the quality of the drugs in the package, the materials for preparing the drug packaging containers should be new materials, and the recycled plastics used by consumers are not allowed to be used in the production of packaging materials that directly contact drugs. The reason is that recycled plastics contain many potentially harmful substances, which may be transferred to drugs through packaging, affecting the quality of drugs and endangering public health

however, there is no specific analysis method to identify recycled plastics at home and abroad. In order to prevent recycled plastics used by consumers from endangering the safety and quality of drugs, this paper attempts to establish a series of analysis methods to identify recycled plastics, which are used to identify whether recycled materials are doped in drug packaging containers, and prevent recycled plastics from entering the drug packaging industry. These analysis methods mainly grasp the two major differences between new plastics and recycled plastics (changes in bulk materials and foreign pollutants). Taking two materials commonly used in the drug packaging industry: polypropylene and polyethylene as models, they carry out identification research on new plastics and recycled plastics, and preliminarily form an analysis and detection system. The analysis and detection system is divided into two levels: the first level is to establish a near-infrared screening model, which can be used to carry out on-site rapid screening. Samples accepted by the near infrared model shall be released; The samples rejected by the near infrared model are taken back to the laboratory for further confirmatory analysis. Confirmatory analysis is the second level. Thermal analysis technology, infrared technology, X-ray fluorescence technology and standard analysis method for packaging materials and containers in direct contact with drugs (YBB method) are used to further analyze whether recycled materials are added to the samples

in the first level, the qualitative analysis model of near-infrared screening application is the consistency test model. The near-infrared qualitative model accurately identifies the new and recycled polypropylene materials, new and recycled polyethylene materials collected in the market; At the same time, two types of consistency test models were used to accurately identify the new and regenerated polypropylene bottles for oral use produced by entrusted processing, as well as the new and regenerated high-density polyethylene bottles for oral use produced by entrusted processing. Among them, the proportion of polypropylene regeneration bottles and high-density polyethylene regeneration bottles doped with recycled materials is as low as 20% and 10% respectively. In addition, a batch of unqualified polypropylene bottles for oral use were detected by near-infrared model in practical application. DSC method and YBB method confirmed that the batch of polypropylene bottles for oral use were doped with recycled materials. The first level of near-infrared screening analysis results show that the near-infrared qualitative analysis model can be used to identify recycled plastics

the thermal analysis technology used in the second level is mainly differential thermal analysis (DSC). The melting behavior, tox value and OIT value of plastic bottles are used as quality indicators to distinguish new plastic bottles from recycled plastic bottles. The melting behavior, tox value and OIT value of the new plastic bottle of a specific brand are the reference values. According to the raw material brand of the sample to be tested, the corresponding melting behavior, tox value and OIT value are compared with the reference values of the new plastic bottle of that brand. All samples to be tested that are different from the reference melting behavior, significantly lower than the reference tox value and significantly lower than the reference OIT value indicate that the sample is likely to be doped with recycled materials. The results show that DSC technology can be used to identify recycled plastics

secondly, review the infrared technology in the second level of oil return pipe, which is the supplement and verification of DSC analysis method. In this study, the characteristic absorption band and correlation coefficient pattern of infrared spectrum were used to identify new polypropylene and regenerated polypropylene, new polyethylene and regenerated polyethylene. The results show that infrared technology can be used to identify recycled plastics

X-ray fluorescence in the second level realizes the analysis of unknown pollutants in recycled plastics by qualitative and quantitative analysis of elements between f-u. In this paper, the wavelength dispersive X-ray fluorescence spectrometer is used to better identify the recycled polypropylene and polyethylene materials, and to better identify whether the low-density polyethylene bottle used for eye drops is doped with recycled materials. The results show that X-ray fluorescence can be used as a basis for judging whether recycled materials are added to the samples

the YBB method in the second level comprehensively evaluates samples, which is the supplement and verification of DSC, infrared and X-ray fluorescence

the research results show that the analysis and detection system can be used to identify recycled polypropylene and recycled polyethylene, and can also be used as a method and model reference for identifying other kinds of recycled plastics after their signing ceremony, which has laid a solid foundation for further promotion and research. It is worth pointing out that this subject has broken through the technical difficulties of identifying recycled plastics by near-infrared technology. The near-infrared analysis method for identifying recycled plastics is established for the first time and has been successfully applied in practical work. It provides an analysis method for China's on-site rapid supervision and inspection of drug packaging products, and also provides a strong technical support for the quality supervision of drug packaging materials in the future. The key technologies involved in this topic have not been reported in the literature, and the research results have been applied for national invention patents, which are innovative and practical. In addition, according to the requirements of inspection and detection for the first time, this paper establishes DSC and X-ray fluorescence analysis methods to identify whether the drug packaging products are doped with recycled materials, changes the situation of low-cost supply of rare earth low-grade raw materials, and provides a methodological guarantee for the laboratory confirmation of recycled plastics, which is innovative and practical

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