Physical and Mechanical Properties of Selected Fruit-bearing and Underutilized Tree Species in the Philippines

Abstract

To help augment the raw material supply of the wood-based industries, the study evaluated the physical and mechanical properties (PMP) of six selected timber species in the Philippines – four fruit-bearing and two underutilized tree species. The fruit-bearing species were “nangka” (Artocarpus heterophyllus Lamk.), “santol” [Sandoricum koetjape (Burm. F.)], “durian” (Durio zibethinus Murray), and “marang” [Litsea perrottetti (Blume) F. Vill.] collected from Bislig, Surigao del Sur (Caraga Region, Mindanao), while the underutilized tree species were “antipolo” [Artocarpus blancoi (Elmer) Merr] and “batino” (Alstonia macrophylla G. Donn) collected from Batangas City and Quezon Province (Region IV, Luzon), respectively. Physical properties included relative density (RD), moisture content (MC), and shrinkage. Mechanical properties covered modulus of rupture, stress at proportional limit, and modulus of elasticity in static bending; compression parallel-and perpendicular-to-grain; shear; hardness; and toughness. Standard testing procedures (ASTM-D143) were followed. Variations on the six species’ PMP were statistically analyzed, including the effect of individual trees and height levels. Among the six species, batino exhibited the highest RD (0.60), followed by nangka (0.49), antipolo (0.47), santol (0.46), marang (0.36), and durian (0.34). The MCs of nangka, santol, durian, antipolo, batino, and marang were 111.07, 121.21, 183.7, 152.68, 85.77, and 189.97% while the volumetric shrinkages (VSs) were 6.67, 6.86, 6.96, 9.07, 12.23, and 9.39%, respectively. The RD of batino was classified moderately high; those of nangka, santol, and antipolo were moderately low; and those of marang and durian were low. There was an inverse relationship between RD and MC in the six species. The VS values of nangka, durian, and santol were classified low; those of batino were medium; and those of antipolo and marang were moderately low. Overall, the mechanical properties of batino were moderately high; those of nangka, santol, and antipolo were moderately low; and those of durian and marang were low. The mechanical properties of the six species were compared with those of the “Philippine mahogany” species traditionally used for construction.