ABSTRACT

The effect of the radial force applied by a ring debarker tip to frozen black spruce logs, obtained at three positions on the stem, was studied. A one-arm ring-debarker prototype was developed, which controlled the radial force, rake angle, and cutting and feed speeds. The experiment consisted of debarking logs using three different levels of radial force. The rake angle (80°), tip overlap (20%), and cutting and feed speeds were kept constant. Debarking quality was evaluated by two criteria: the proportion of bark remaining on log surfaces and the amount of wood in bark residues. Log characteristics (dimensions, eccentricity, and knot features), bark/wood shear strength, and basic densities of sapwood and bark were also measured. Experiments revealed that log position on the stem did not affect debarking quality. The results also showed a significant effect of the radial force: the amount of bark remaining on log surfaces increased and the proportion of wood in bark residues decreased as radial force decreased. The effects of log eccentricity, bark/wood shear strength, and the proportion of knot surface on the debarking quality were examined. These results give useful information to improve debarking quality within the studied range of radial force, log diameter, and debarking parameters.

摘要

研究了环剥皮器尖端对在茎上三个位置获得的冷冻黑云杉原木施加的径向力的影响。开发了一个单臂环剥皮机原型，该原型可控制径向力，前角以及切割和进给速度。该实验包括使用三种不同水平的径向力对原木进行剥皮。前角（80°），刀尖重叠（20％）以及切割和进给速度保持恒定。剥皮质量通过两个标准进行评估：残留在原木表面的树皮比例和树皮残留物中的木材量。还测量了原木特性（尺寸，偏心率和结特性），树皮/木材的剪切强度以及边材和树皮的基本密度。实验表明，茎上的原木位置不会影响剥皮质量。结果还显示了径向力的显着影响：随着径向力的降低，残留在原木表面上的树皮数量增加，木材在树皮残留物中的比例降低。检查了对数偏心率，树皮/木材剪切强度以及结面比例对剥皮质量的影响。这些结果为在径向力，对数直径和剥皮参数的研究范围内提高剥皮质量提供了有用的信息。