Optimization of Wood-Plastic Composites by Response Surface Method

To improve the material properties of wood-plastic composite, poplar fiber and polyethylene powder were used as the main components, a hot-press experiment was conducted using response surface methodology, and the relationship between processing parameters (wood/plastic ratio, hot-press pressure, and time) and experimental result (internal bond strength and thickness swelling) were explored. According to the experimental results, the increasing wood/plastic ratio led to the lower internal bond strength and higher thickness swelling. However, with the increase of both hotpress pressure and time, internal bond strength increased first and then decreased, and thickness swelling decreased first and then increased. Meanwhile, two mathematical models were developed with high feasibility, and the significance of the influence of each term in the models was also analyzed. The models were able to predict and optimize internal bond strength and thickness swelling. Finally, optimal processing parameters were determined as wood/plastic ratio of 1.09, hot-press pressure of 198.38 MPa, and hot-press time of 8.31 s, with respect to the higher internal bond strength and the lower thickness swelling. This work hopes to provide scientific support for the industrial processing of wood-plastic composite.