Modelling of mould growth on pine sapwood: the preliminary analysis of input parameters in a logistic mould growth model

Abstract

This paper deals with a logistic growth equation which was used for calculations of mould development on wood in time. The values of input parameters were determined by mutual comparisons of the logistic growth equation and synthetic mould growth data. Synthetic mould growth curves were calculated by the Finnish mould growth model for pine sapwood. A transition function between dimensionless mould index (the state variable of the Finnish mould growth model) and microscopic mould coverage fraction (the state variable of the logistic mould growth model) was proposed to facilitate numerical comparisons between both models. The insight to input parameters of the logistic mould growth model was then gained by plotting optimal values of parameters as a function of temperature and relative humidity, or moisture content. The setting of input parameters in mould growth models was then briefly discussed. It is concluded that further development of mould growth models should be based on systematic comparison with mould growth experiments. Not only growth under favourable conditions, but also the regrowth process after desiccation period must be correctly addressed in the model.