Parameters of Strand Alignment Distribution Analysis and Bamboo Strandboard Properties

Strand length, free-fall distance (FFD), and plate spacing was varied to control the strand alignment distribution of strandboard. To determine the strand angle distribution, photographs of strands were recorded as digital image data, and strand angle analysis was conducted using a modified von Mises distribution function. A part of this measurement was used as a reference for the alignment in the board produced. The results of strand alignment distributions showed that the k value was a function of strand length, FFD, and plate spacing. The k value can be improved by adjusting the plate spacing closer to the strand width, shortening the FFD, and using long strands. The power equation model can describe those relations. The bending properties and linear expansion (LE) were greatly affected by the FFD and the plate spacing. The use of low FFD and narrow plate spacing improved the bending properties. The decreasing bending properties in the parallel direction could be comparable to the increasing ones in the perpendicular direction. The contribution of bamboo strand in the longitudinal direction affected these results.