Laboratory testing and computer simulation of blue stain growth on and in wood coatings

Wood coatings are susceptible to fungal growth which might cause a reduction of the performance and ensuing service life apart from aesthetical depreciation. Therefore, manufacturers strive for highly resistant systems ensuring sufficient quality protection. Experimental tests complemented with growth modelling help to achieve insight in pattern development. The purpose of this work is twofold. First, the influence of different wood species and weathering of coatings are examined and secondly the fungal growth on coated pine sapwood is simulated in silico. Therefore several coating systems were applied on different wood species and samples were subjected to the EN 152 reverse blue stain method. Scots pine sapwood samples were analysed in-depth with a 3-D reconstruction technique. Moreover, a new mycological test, accelerating growth of fungi, was also implemented. Second, for computer modelling cellular automata were used. The reverse method appears to be a more realistic approach of exterior conditions and offers the possibility of resistance calculation. The new mycological test gave promising results and data were comparable with those of the reverse method.