Effects of accelerated and natural weathering on fire-retarded industrial wood composite

This study shows the impact of aging on the fire behavior of a fire-retarded polyvinyl chloride wood composite cladding intended for outdoor use. Two sets of composite wood cladding elements were examined: one aged naturally under exposed outdoors conditions for 1 year and the second, which underwent artificial accelerated aging. Optical microscopy, electron probe micro-analysis, and solid-state nuclear magnetic resonance of 27Al were used to investigate changes in the material properties after aging, distribution of chemical compounds, and aluminum environment. This study reveals the impact of different aging procedures on the physicochemical modifications of the composite material. In addition, after aging, the fire behavior of the two sets of composites as a function of fire exposure time was evaluated by cone calorimetry. Then, the natural aged composite was evaluated on a larger scale with the single burning item. The results surprisingly demonstrate that whatever the aging, the fire behavior of these wood composite was not affected.