Determining Tensile Properties of Sweetgum Veneer Flakes

Rotary-cut sweetgum veneer flakes measuring 3 inches along the grain, 3/8 inch wide, and 0.015 inch thick were stressed in tension parallel to the grain at gage lengths of 0.50 to 1.25 inches. These flakes had an average tensile strength of 9,400 psi for the smaller gage length classes and 8,000 psi for the upper range of gage lengths. Tensile moduli determined by crosshead movement ranged from 460,000 psi to 675,000 psi, but strain gage measurements indicated the moduli could be 1.5 to 3.5 times larger. Flakes compressed in a 42 lb/ft3 (0.673 g/cc) simulated flakeboard were evaluated with a 0.75-inch gage length. Average moisture content of specimens ranged from 5.5 to 6.5 percent. Platen pressure with heat increased density of core flakes 6.3 percent and that of face flakes 13.9 percent above the density of untreated flakes (0.55 g/cc). Core flakes decreased 6.5 percent and 7.25 percent in tensile strength and modulus; face flakes had 7.6 percent greater tensile strength and 9.8 percent greater modulus than unpressed controls. Although the tensile properties-grain angle regression analyses were significant, the low correlation coefficients indicated that over 60 percent of the observed variability was unexplained by the grain angle regression.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member