Research Of Paper Mill Sludge Physicochemical Properties And Preparation Of Wood-Plastic Composites

Paper industry produces large amounts of wastewater. Paper mill sludge has a complex composition, dehydrated by papermaking wastewater, with arbitrary treatment will not only cause serious damage to the environment, but also a waste of resources. Wood-plastic composite(WPC) is a new type material, use wood fiber as reinforced material compound with thermoplastic matrix by pretreatment. It combines the advantages of wood and plastic, can slow down the situations of China’s lack of timber resources, and has plastic advantages of water-resistant, anti-corrosion, easy coloring simultaneously. The utilizations of paper mill sludge, not only provide a new direction of paper sludge utilization, but also effectively reduce the paper industry pollution of environment, have a good social and economic value.The article discussed the paper sludge physicochemical properties and preparation of paper sludge/PVC wood-plastic composites, explored the developments and applications. The main research content and results are as follows:Moisture content of dry sludge is14.37%, organic content is51.24%, pH value is8.05, cellulose content of dry sludge is21.66%, analyze heavy metals of sludge ash, all of the heavy metal content are below national standards.Observe fiber morphology of dry sludge by scanning electron microscopy, fibers spread on the sludge surface. Analyze the potential groups and speculate substances of paper sludge by fourier transform infrared spectroscopy, besides cellulose paper sludge also contain kaolin and other organic substances.Use paper sludge as raw material, preparing wood-plastic composites by hot press molding. The impacts of sludge filling content, pressing time, pressing temperature, pressing pressure, coupling agent content, lubricant content on WPC mechanical properties are studied to decide the most economic processing conditions and formulations according to WPC standards. The results showed that:the WPC flexural strength is55.56%over the standards of 《GBT24137-2009》to31.11MPa, tensile strength is58.11%over the standards of《DB44/T349-2006)) to15.81MPa, in the conditions of sludge filling content of50%, pressing time of10min, pressing temperature of180℃, pressing pressure of6MPa, silane coupling agent content of2%, lubricant content(stearic acid) of0.3phr.Study the application properties of moisture content,24hours bibulous rate of weight gain, water resistance, etc. Results show that composites properties of moisture content and24hours bibulous rate of weight gain are significantly reduced treated by different modifiers. Stearic acid lubricant is added to reduce the water absorption of composites. The water resistance of modified composites is significantly improved, the water resistance of composites modified by KH560is more excellent than modified by maleic anhydride. The section electron microscopy figures of different modification methods show that the interfacial compatibility of modified composites is significantly improved, the interfacial adhesion of composites modified by KH560is most ideal. The FTIR shows, the characteristic functional group absorption peaks of water sludge change modified by KH560.