Method For Obtaining Wood/Bark Adhesion Measurements on Small Samples

Using the Instron Tester, a procedure has been developed for measuring wood/bark adhesion on small samples. Using very small, specially prepared samples, wood/bark adhesion measurements were made on twenty-four hardwoods and eighteen conifers. High dormant season wood/bark adhesion in hardwoods was found to be associated with the presence of fibers in the inner bark. The procedure appears to be useful in identifying difficult-to-debark species and evaluating methods of reducing adhesion

Morphological and Bark Strength Characteristics Important to Wood/Bark Adhesion in Hardwoods

Dormant season wood/bark adhesion was determined for twenty-four hardwood species using a previously described Instron testing machine method. Wood/bark adhesion was compared, using simple and multiple correlation techniques, with bark specific gravity, inner bark strength, bark toughness, wood specific gravity, wood toughness, percent bark fibers, and percent sclereids. Wood/bark adhesion was found to be positively correlated with percent bark fibers, bark toughness, and inner bark strength. Wood/bark adhesion was negatively correlated with percent sclereids in the bark. Morphologically, it appeared that the presence of fibers increased inner bark strength, sclereids decreased inner bark strength, and inner bark strength had a major influence on wood/bark adhesion. A multiple correlation comparison employing wood toughness and inner bark strength accounted for 69% of the wood/bark adhesion encountered