Engineering Properties of Palmyra Palm (Borassusa ethiopum) Seeds at Different Moisture Contents

Abstract

The data on the engineering properties of Palmyra palm seeds and kernels required for design of the machine are not established. The removal of the kernel from the shell is usually achieved using traditional method by roasting the seed and then break open with stone, which is time consuming and stressful. This research was carried out to determine some physical and mechanical properties of Palmyra palm seeds at three different moisture content levels of 8.09 %, 7.04 % and 5.50 %. The physical properties such as axial dimension, geometric mean diameter, surface area, static coefficient of friction, true density, bulk density and porosity were determined. The mechanical properties determined were compressive force, compressive stress and deformation both at peak and at break using Instron hydraulic universal tensile testing machine. The seed had major, intermediate, minor and geometric diameter as 10.89±1.65, 7.76±1.93, 9.14±1.84 and 9.11±1.53, respectively. While the major, intermediate, minor and geometric diameters for the kernel were 8.14±1.37, 5.08±1.19, 2.96±0.93 and 4.92±1.07 respectively. The mechanical properties of seed and kernel evaluated for force at peak, force at break, stress at peak, stress at break, deformation at peak and deformation at break were 8.03±1.87 𝑘𝑁, 10.82±0.23 𝑘𝑁, 0.46±0.07 𝑘𝑁/mm, 1.46±0.19 𝑘𝑁/mm, 3.98±0.19 mm, 4.10±0.16 mm and 17.14±1.66 𝑘𝑁, 36.44±8.24 𝑘𝑁, 0.14±1.37 𝑘𝑁/mm, 10.96±8.24 𝑘𝑁/mm, 5.21±1.28 mm and 5.53±1.33 mm respectively. The coefficient of static friction was highest on wood with 0.36±0.06 and 0.44±0.03 for seeds and kernel respectively. The results obtained from the experiment will contribute immensely to the existing knowledge aimed at solving the problems of equipment design to handle the processing of the seeds.