Wood-to-bark adhesion of subalpine fir ( Abies lasiocarpa) in extreme temperatures

Abstract

Wood-to-bark adhesion strengths were tested at 25 to −78°C under moisture contents of 0–200%. The freezing temperature of the cambium appeared to be between –20 and −40°C. The low freezing temperature was assumed to be due to the high pectin and protein contents in the cambium cells. At temperatures above the freezing point of the cambium (−20 to 25°C), the adhesion strength was curvilinearly and negatively related to moisture content. At temperatures below the freezing point of the cambium (−40 to –78°C), adhesion strength was not correlated with moisture content. For practical application, maintaining logs at high moisture content and temperatures above –20°C would assure a good debarking and yield high quality wood chips for pulping, with less wood loss to hog fuel.