A study on physical and mechanical properties of cashew nuts for development of harvesting and processing systems

This study investigated physical and mechanical properties of cashew nuts grown in Tanzania, important for equipment development. The dimensions of three principal axes (width, length, thickness) and mass of cashew nuts were measured. Coefficient of friction on plywood, hardwood, canvas, mild steel, plastic and galvanized steel and bulk density together with the angle of repose were determined. The coefficients of friction on various surfaces were found to be between 0.23 and 0.46 and the static repose angle was 23°.The cashew nut sizes ranged from 24 to 41mm in length, 13 tol 8rnm in thickness and 18 to 27mm wide. Raw and steamed nuts were subjected to compression loads in three different directions using flat surfaces. The breaking forces for raw nuts ranged from 500 to 700N. While for steamed (boiled) cashew nuts were from 100 to 142N.The obtained parameters will be very valuable in the design and development of future cashew nut harvesting, handling and processing systems. On the other hand, it was found that loading orientation, size of sample and sample pre-treatment affect the values of force required to break the nut and its failure pattern.