Sink-float Separation And Recovery Of The Mixture Of HDPE/PP

In order to separate mixed recycled plastics HDPE/PP, HDPE (recycled bottle caps) and PP (recycled bottle caps) were studied in this research. Self-designed separator was used to separate the recycled plastics HDPE/PP with industrial ethanol and water mixture as the separation medium. Effects of parameters such as the separation amount of the separator, recycled HDPE and PP content before separation, the size of recycled plastic, the density of separation medium and the amount of wetting agent CaLS etc. on the sink-float separation of The grade, recovery, and yield of the product after separation were investigated in a laboratory and the optimized conditions for sink-float separation of the mixed plastics HDPE/PP.Results of research showed that:the separation amount of the separator was 500g for the optimized effects of the separation of HDPE/PP.For the separation of HDPE in the recycled plastics, the content of recycled HDPE before separation was above 30%, using the separation of self-designed separator, the grade of HDPE in the product after separation was above 97%. The separation condition was that the density of separation medium was between 0.910g/cm3 and 0.930g/cm3 and the amount of CaLS was 6g.When the density of separation medium was between 0.910g/cm3 and 0.920g/cm3, the recovery of the product after separation was above 85% and the yield of the product after separation was below 61%. If the amount of CaLS was 6g, the recovery of the product after separation was above 94%. As the density of separation medium was 0.930g/cm3, the yield was below 40%.For the separation of PP in the recycled plastics, the content of recycled PP before separation was above 40% and the density of separation medium was 0.910g/cm3, the grade of PP in the product after separation was above 90%. The amount of CaLS was 6g and the grade of PP in the product after separation was above 94%. The recovery of PP was above 97% and the yield of PP was below 80%.