Efficacy of curtailment announcements as a predictor of lumber supply

There is limited information available on the susceptibility of woodfiber/thermo-plastic composites to biodegradation. The objective of this paper is to report on the laboratory decay resistance of model composites. Polypropylene/pine composites were made with 30, 40, 50, 60, or 70 percent wood contents and exposed to brown- or white-rot fungi. In addition, 50/50 woodfiber/thermoplastic composites were treated with zinc borate (ZB) preservative at loadings of 1,3, or 5 percent and evaluated against the brown-rot fungus. The effect of surface abrasion on decay was investigated by sanding the surface of some samples. Weight loss was proportional to wood content in the unpreserved composites. Substantial weight losses were observed for all unpreserved composites tested with the brown-rot fungus, while white-rot attack was only significant in the high wood content composites, particularly when the surface of the samples was sanded prior to exposure to the fungus. The incorporation of ZB into the composites provided protection from fungal attack at all loadings.