Properties of southern pine needles

Abstract

To investigate properties that might be related to utilization, needles were sampled on one tree of each of the four major species. Tensile strength was measured on loblolly needles only; it ranged from 4,630 to 6,980 psi. Maximum load averaged 4.1 pounds per needle, with a modulus of elasticity of 220,000 psi. Specific gravity (ovendry weight, green volume of individual needles of the four species varied from 0.34 to 0.45. Upon drying, loblolly pine needles averaged 1.58 percent longitudinal shrinkage; longleaf. 1.65; shortleaf, 1.85; and slash, 2.31. Total ash for loblolly needles was 3.46 percent. Green moisture content (dry weight basis) was: loblolly, 97 percent; longleaf, 112; shortleaf, 122; and slash, 121. Heat of combustion was 9,030 Btu per ovendry pound in specimens with an alcohol-benzene extractive content of 28.8 percent. Fibers up to 5 mm in length (usually 1.2 to 3 mm) were observed in macerated tissue.

Citation

Howard, E.T. 1973. Properties of southern pine needles. Wood Science 5(4):281-286