Refined Regeneration Process and Comprehensive Evaluation of Recycled Copolymer Polypropylene Plastic from Waste Milk Tea Cups

High Resolution Image Download MS PowerPoint Slide The recycling of waste copolymer polypropylene (PP) milk tea cups has become an important direction for practicing low-carbon development. Currently, the recycling of waste PP milk tea cups faces difficulties such as complex impurities, low purification efficiency, and unclear utilization methods, which restrict its large-scale utilization. This study established a physical purification process suitable for large-scale production, preparing high-purity recycled copolymer PP particles through flotation, alkaline hot water cleaning, color sorting, and melt filtration processes. The results show that the recycled PP particles exhibit qualified physical properties. The average melt flow index is 17.76 g/10 min, the tensile strength is 33.25 MPa, the flexural strength is 38.18 MPa, the average density is 0.902 g/cm 3, and the ash content is 0.075 wt %, which are close to the level of virgin PP. In terms of appearance, the average haze is 85.68%, the transparency is 60.35%, and the content of black spots (diameter ≥0.1 mm) is only 64.72 × 10 −3 wt %. Typical restricted heavy metals specified in the RoHS 2.0 standard, such as cadmium, lead, mercury, and chromium, were not detected. These results verify the high feasibility of the process, providing technical support for the recycling of copolymer PP from waste milk tea cups. Meanwhile, the reutilization pathways of recycled PP were discussed in combination with modification technologies. This study is of great significance for promoting the recycling of waste PP milk tea cups and advancing the resource utilization of plastic waste.