Thermoplastic flow behavior of steamed wood flour under heat and compression

In this study the thermoplastic flow behavior of steamed wood flour was investigated. First it was demonstrated that steamed Japanese beech flour flowed out of the nozzle under compression at high temperature in a thermal flow test with a capillary rheometer. The effects of the steaming temperature, steaming time, compressive pressure, and moisture content of wood flour on the thermal flow temperature were examined. It was shown that the higher the steaming temperature and compressive pressure, the lower the thermal flow temperature. Also, the thermal flow temperature of the sample steamed at 200°C for 20 min became lowest and increasingly higher over time. Furthermore, the thermal flow temperature became linearly low with increasing moisture content of the sample under 15%, whereas it became essentially constant over 15%. It is clarified that compressive pressure and moisture content as well as the steaming conditions profoundly affect the thermoplastic flow behavior of steamed wood flour.