ABSTRACT

An investigation was carried out on some engineering properties of oil bean seeds (Pentaclethra Macrophylla, Benth) to obtain some data required for the design and development of processing and/or handling machine for the bean seeds. The engineering properties investigated were physical and mechanical properties of the seeds. The study was conducted at three moisture content levels namely; 13%, 20% and 30% (wet bases) and on the three diametric positions or axis (major, minor and intermediate diameters) of the seeds. The physical properties studied include: size, shape, volume, surface area, sphericity, bulk density, weight and angles of repose while the mechanical properties were: rupture force, deformation, bio-yield force, compressive strength, stiffness and toughness of the seeds. Results obtained revealed that at the three moisture content levels, the bean seeds had average size range of 30.3 1mm to 35.70mm, volume range of 15.75mm to 23.02mm, bulk density of 823.31 to 1096.65g/mm3, sphericity, porosity and surface area of 0.509mm to 0.523mm, 30.84mm to 42.27mm and 119.96mm to 150.13mm. The angle of repose of the seeds with wood materials ranges from 98.4°to 102.30, with metal, the angle of repose range from 8 1.2°to 99.6°and with glass material; it ranges from 83.10 to 86.80. Results also revealed that the force to rupture oil bean seed range from 4.SKN to 1.9OKN at the major diameter, 3.OSKN to 1.29KN at the minor diameter and 4.75KN to 2.75KN at the thickness, the corresponding deformatiOn at these points ranges were 2.8 8mm to 4.18mm for major diameter, 2.30mm to 3.54mm and 1.95mm to 3.63mm for minor diameter and thickness respectively for the three levels of moisture content studied. Finally the mean values of bio-yield force, compressive strength, stiffness and toughness of oil bean seeds were 3.8OKN, 0.2315N/mm2, 1.4KN/mm and 0.96Kj/mm3 respectively. The analysis of varies (ANOVA) showed that the mechanical properties of oil bean seed at all moisture content were highly significant at 0.00 1 and 0.007 level. The mechanical properties decrease with increase in moisture content of the seeds. It is therefore recommended that more studies should be carried out on the engineering properties of biomaterials to enhance the design and fabrication of machines, suitable for their processing.