A comparison study on creep behavior of wood–plastic composite, solid wood, and polypropylene

Abstract

In this study, creep/recovery behavior of wood flour/polypropylene (PP) composite was compared with solid wood and PP. Wood flour–PP composite samples (strips with 10 mm thickness and 70 mm width) were made using a laboratory twin-screw extruder. Short-term flexural creep tests at 30% of ultimate bending load were performed using flexural creep equipment. Total time to complete every test was 120 min (60 min creep and 60 min recovery). Creep parameters (relative creep, fractional deflection, creep rate, etc.) were measured for all creep test samples. The result showed that the relative creep in wood–plastic composite (WPCs, with or without coupling agent) is significantly higher than solid wood and lower than PP. Also, it was observed that the creep rate in WPC (with or without coupling agent) is significantly lower than plastic, but is approximately equal to solid wood. The use of coupling agent decreased relative creep and fractional deflection in wood flour–PP composite panels. Findley creep model predicted creep strain with a high acceptable accuracy for studied materials.