Simulation of the mat formation process

The parameters of the hot-pressing process have a substantial effect on the final mechanical and physical properties of wood-based composites. The num ber of interacting variables during the consolidation is prohibitively larg e to assess a wide variety of data by experimental means. A combined stocha stic and deterministic model, based on fundamental engineering principles, was developed and validated for establishing the critical relationships bet ween the processing parameters and the physical properties of oriented stra ndboard (OSB). In the first phase of this research, a Monte-Carlo simulatio n model was developed for describing the spatial structure of a three-layer OSB. The model was designed to mimic the strand deposition during the mat formation, including the three-dimensional spatial geometry, orientation, a nd density of the strands. These physical characteristics of the mat format ion process were considered as stochastic variables that can be described b y well-developed probability distributions. The parameters of these underly ing distributions were derived from data collected on industrial strands by using an image analysis technique. The model superimposes a grid on the si mulated mat and is capable of computing the number of strands, as well as t he thickness and density of the mat, at each grid point. Additionally, it c an predict the change in several void volume fractions and strand contact a rea within the mat during the consolidation. The model has application to w afer. particle. and fiber mats as well. This structural simulation model is the basis of further model development that describes the heat and mass tr ansfer processes, and the viscoelastic nature of the hot-pressing operation during OSB manufacturing.