This study examines the effect of wood-chip dimensions on pulp quality
. Chip fractions were classified by size, and chips in each fraction w
ere measured manually to determine precise distributions for length, w
idth, and thickness. The classified fractions were then cooked (low-yi
eld magnesium bisulfite), and pulp handsheets were tested. Pulp qualit
y for small chips (R 1/4-in. fraction) matched or exceeded that of lon
ger chips (R 3/4-in. fraction). Statistical analysis revealed that the
skewness and kurtosis of the distribution in chip width had a signifi
cant effect on tensile strength, accounting for almost 50% of the vari
ability in tensile energy absorption. Skewness in chip-width distribut
ion also had an important effect on tear index, along with skewness in
chip thickness and kurtosis in chip length. Selectivity of delignific
ation varied with chip size distribution at the same overall yield. Ch
anges in the skewness of chip-width distribution alone accounted for o
ver half the variation in kappa number.