Influence of paper mill sludge on the long term hygroscopic behavior of flat pressed wood-plastic composites

Lignocellulosic material used as raw material in pulp and paper production due to major chemical alterations produce different waste compounds and composite manufacturing is an area providing the opportunity to utilize such wastes. In order to investigate the feasibility of using papermaking sludge in composite production, four combinations of wood flour/ papermaking sludge/ high density polyethylene ratio were formulated, then composite panels were made and the physical properties of manufactured panels were evaluated. The content of maleated polyethylene (MAPE) and the polymer was constant 2% and 38% respectively, for all formulations. The results indicated that long term water absorption in particular thickness swelling decreased with increasing sludge content. Furthermore, moisture diffusion coefficient of samples containing 30% sludge and 30% wood flour was more than others. The results revealed that using papermaking sludge can be an alternative option for lignocellulosic raw material.