بررسي مقايسه اي رفتار خزش كامپوزيت آرد چوب- پلي پروپيلن با تخته فيبر نيمه سنگين و تخته خرده چوب

A Comparative Study on Creep Behavior of Wood Flour-Polypropylene Composite, Medium Density Fiberboard (MDF) and Particleboard

The creep/recovery behavior of wood flour-polypropylene was compared with medium density fiberboard (MDF) and particleboard. For this purpose, wood flour-polypropylene composites (with and without compatibilizer) were manufactured by using a laboratory twin-screw extruder. The MDF and particleboard panels were obtained from local producers. Short term flexural creep tests at 30% of ultimate bending load were performed by using flexural creep equipment. The total time to complete every test was 120 min (60 min creep and 60 min recovery). Also Findley creep model was used for the prediction of creep behavior of the materials under study. The results showed that fractional deflection and relative creep in wood flour-polypropylene composites are higher than MDF and particleboard whereas MDF and particleboard exhibited higher percent recovery rather than wood flour-polypropylene composite. Creep modulus at the first phase of creep in wood flour-polypropylene composite was higher than MDF and particleboard but more decreases were observed for creep modulus of wood-plastic composite at the end of creep phase. Coupling agent (MAPP) improved creep/recovery behavior of wood flour-polypropylene composite. Also Findley creep model predicted the creep behavior of studied materials very well.