Organoclay additive for plywood protection against brown and white rot fungi

Abstract

In this study, antifungal properties of an organoclay additive were investigated. Two types of organoclay (red and white) were tested in Petri dishes to determine their toxicity against the brown rot fungus Coniophora puteana and the white rot fungus Trametes versicolor. Red organoclay was more efficient than the white one and, depending on the fungus, inhibited or stopped the fungal growth. Red organoclay was chosen as an additive to produce a new type of plywood product. Biological durability of this plywood product was determined according to the methods: NF B 51-295 (bending strength test) and LVS ENV 12038:2002 (mass loss test). The loss in bending strength exceeded 81% and 65% after exposure to brown and white rot fungi, respectively. The mass loss of the plywood product after the decay test was higher than 3%, which defined the material as not fully resistant against decay fungi. According to CEN/TS 15083-1:2005, the plywood product corresponded to the durability class 3 (moderately durable) to 5 (not durable) depending on the fungus.