Some physical, mechanical and aerodynamic properties of pine (Pinus pinea) nuts

Selected physical, mechanical and aerodynamic properties often required for the designing of storage, hopper, handling and processing equipment were determined for pine nuts, at a moisture content of 5.48% (db). The average of each of the three principal diameters, geometric mean diameter and nut mass were 18.67, 8.97, 7.39, 10.72 mm and 0.77 g, respectively. Mean values for nut volume, sphericity, surface area and projected area were 417.87 mm3, 57.53%, 364.46 and 151.24 mm2, respectively. The true density, bulk density and porosity were 983.59, 619.85 kg/m3 and 36.96%, respectively. Cracking forces of pine nut for loading on the lateral axis, vertical axis and thickness were determined to be 429.27, 639.53 and 468.18 N, respectively. The coefficient of static friction was 0.46 on plywood, 0.43 on galvanized steel sheet and 0.35 on fibreglass. Dynamic angle of repose for the three structural materials namely plywood, galvanized steel sheet and fibreglass were found to be 26.18°, 23.52° and 15.21°, respectively. The terminal velocity for the nut, kernel and hull were 8.23, 6.98 and 3.76 m/s, respectively.