Separation And Modification Of PE From The Wasted Paper/Alauminum/Plastics Composite Packaging Materials

With the rapid development of the national economy,composite packaging materials are extensively used in packaging areas due to its excellent performance.One of the most common composite packaging materials is the paper/aluminum/plastic compositematerials and the Tetra Pak is most representative.There are two kinds of wastedpaper/aluminum/plastic composite materials,the one is the leftover materials with a relatively high quality from industry during the productive process,another is the used soft drinks packaging materials,such as milk boxes,beverage boxes and other packaging materials.In China,there are more than 100 billion Tetra Pak boxes are wasted every year,while the recycling rate of materials is less than 20%.Hence,How to recycle the wasted aluminum-plastic composite materials is becoming the focus of social concerned.Firstly,the separation and high-value utilization technology of wasted paper/aluminum/plastic composite packaging materials were discussed,the modification and application technologies of the recycled polyethylene(r-PE)at home and abroad were reviewed.Recently,the "Extended Producer Responsibility" is issued.Accordingly,the significance of establishing the systems for green recycling,effective utilization of wasted packaging materials is presented.Secondly,an in-depth discussion on the separation and high-value utilizationtechnology of wasted paper/aluminum/plastic composite packaging materials was performed.Based on the engineering practices in the enterprise,a plan for modifying the production lines of wasted paper/aluminum/plastic composite packaging materials recycling process were offered for the purpose of improving the efficiency and production quality.A series of patents about the study have been applied for.Thirdly,the structure and basic feature of the r-PE obtained from the wastedpaper/aluminum/plastic composite materials were characterized.The results show that the main components of r-PE are LDPE and LLDPE.There are also a small amount of PP,talc and other impurities in the recycled materials.The r-PE shows lower melt viscosity and better process fluidity than a virgin PE.Though r-PE possesses similar levels of tensile strength and flexural properties to the virgin PE,its elongation and notch impact strength significantly decrease due to its ageing and degradation during the recycling process.In this paper,a new toughening agent F developed by our research group was employed to toughening modify the obtained r-PE.The results show that the introduction of new toughening agent F significantly enhances the toughness of r-PE.Finally,in order to broaden the application,r-PE was tried to be used as a material for 3D printing.The results show that,As-obtianed r-PE has poor formability in the 3D printing process.However,with the presence of compatilizer,the r-PE modified by PLA gives a high strengthen and accuracy in its 3D printing products.