Minimizing hot-press time in the manufacturing process of wood plastic composites

In this study، the reduction in the hot press time using high thermally conductive fillers and the influence of these fillers on physical and mechanical properties of end products was investigated. Variable factors in these treatments are type and content of fillers. Press time and other factors such as the amount of wood flour، board density، and other conditions of press were fixed. Composites were prepared from Beech (Fagus orientalis) flour، Polypropylene، MAPP، and conductive fillers such as flake and powder graphite (carbonic fillers)، and Alumina (ceramic filler). Fillers with contents of 5 and 10% in 15 and 20 minutes for press time were utilized. A thermocouple was utilized to measure the temperature in the core of composite and to determine the time being panel core as the same temperature as the hot press surface. It showed that fillers reduce press time as 2-4 minutes. Mechanical tests including tension، bending، Impact and hardness were performed. Fillers except of flake graphite had no restriction in mechanical properties. Water uptake and swelling as physical properties were also measured and fillers didn’t have a significant effect on these tests. To validate the experimental results، thermal conductivity of composites was determined and the increase in this property was evaluated. The increase in samples contain flake and powder graphite was more remarkable than those contain Alumina.