Abstract
Dimensions of wood chips from logging residue stems and comminuted with a cutter-type chipper were measured to examine size distributions and analyze the relationship between tree species and shape of the logs. Size distributions of the chips (destined for burning in a wood chip boiler), i.e. length, width, and thickness were obtained through sieving and a stratified sampling method and expressed with log-normal distributions. Chip length and width of Chamaecyparis obtusa were significantly larger than those of Cryptomeria japonica which has a smaller specific gravity. The proportion of chips with greater width was significantly greater for larger diameter logs than for smaller diameter logs. There was no significant relationship between chip thickness and length-width ratio with the factor of tree species and log shape. Chips larger than a nominal sieve size often go through the sieve; however the results suggest that the actual length of sieved chips can be controlled by appropriate selection of sieve size as related to chip size distribution.
