Highly filled wood/poly(vinyl chloride) (WPVC) composites were manufactured in five different cross sections by using an industrial-scale twin-screw extruder. The flexural properties of such composites were evaluated, with the effects of sample direction, span length, and rate of loading also being taken into account. The experimental results suggested that the cross section design of WPVC composite products had a significant effect on the flexural properties. Better flexural properties were obtained when testing the WPVC composites in an edgewise loading direction. The findings of this work suggested that a low number of hollow cores with thick flanges and webs should be used to obtain a composite with better flexural properties. The WPVC composite with low density was observed to exhibit lower flexural strength, and the rate of loading had a marginal effect on the flexural properties of the composites. The minimum L/d ratios of the WPVC beam to be used for steady flexural properties were 10 in the edgewise direction and 16 in the flatwise direction.

The creep and fatigue properties of two wood/ poly(vinyl chloride) (WPVC) composite beams were studied under flexural and cyclic deformations. The effects of cross-section design and load direction were the main interests. The weight ratio of the wood and PVC compound used was 1:1, and the composites were produced by using an industrial-scale twin-screw extruder. In creep testing, the changes in WPVC beam displacement for the edgewise and flatwise directions increased with time. The WPVC composite with a greater size (thickness) and number of cores had the higher creep resistance. Testing a WPVC composite in the flatwise direction gave less time-dependence than testing in the edgewise direction. The recommended applied loads for optimum creep resistance of the WPVC specimens were found to be 20 and 30% of the ultimate load to failure, depending on the size and number of cores for the cross-section used. In fatigue testing, the number of cycles to failure for both WPVC composite specimens tested in the flatwise direction was greater than that for testing in the edgewise direction.

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