Waste Pvb Plastic Recycling Technology Research

For PVB plastic, it is mainly composed by the PVB resin, plasticizer, pigment and other pose. Decolorization of colored PVB plastic and recycle of plasticizer and resin in the colorless PVB plastic were served as study purpose in this paper. Based on the existing "selectively dissolve pigment-vaporize and recycle solvent" minitype experiment, took place expander level experiment of decolorization technology for PVB plastic to determine the feasibility of the process of industrialization application; Simulated colorless PVB plastic was served as object of study, the feasibility and related parameters of the supercritical fluid extracting plasticizers in the colorless PVB were investigated, in order to provide related technical infrastructure for recycle of containing solids impurities PVB plastic.Papers used gas chromatography-mass spectrometry to analysis the type of plasticizer in the PVB film, ascertaing that the plasticizer was three glycol bis (2-ethylhexyl acid) ester(3GO); and using thermal gravimetric analysis (TG) and differential thermal analysis (DSC) to study the thermal degradation of PVB. In the air, PVB resin was three-step degradation, while in the argon gas, PVB resin was two-step degradation.Optimized single-stage decolorization time in the semi-industrial level was 60 min; optimized single-stage ratio of liquid to material was 40 ml:1g; the best decolorization series was four. Experienced four series decolorization, the color of green waste PVB plastic changed from the deep-green to colorless. Through research we could conclude, using atmospheric distillation technology to recycle TSJ-1311, recovery of PVB resin was up to 99% after decolorization. Recovery of solvent in the PVB was up to 97%, recovery rate of colored solvent TSJ-1311 could reach 98%, gross recovery rate of solvent TSJ-1311 could reach 98%.The swelling PVB resin experienced only slow drying stage. After statistical analysis, Two-term model had shown a good suitability between the predicted drying curves and drying curve of the experiment, the equation of kinetic was:X=1.18607exp (-0.00079t)+1.54755exp (-0.0038t).Plasticizer in the PVB had been extracted using supercritical fluid technology, the optimum parameters were:extraction temperature was 55℃, extraction pressure was 25 MPa, CO2 flow rate was 25 L/h, extraction time was 180 min, entrainer was petroleum ether, yield of plasticizer reached 78.26%. After the supercritical CO2 fluid extraction, performance and structure of plasticizer and PVB resin were not changed through the contrast of infrared spectra, this showed that the supercritical CO2 fluid extraction technology could maximizely retented characteristics of resin and plasticizer, was a scientific way of extraction and separation.