In developing processing machines for plant materials, the frictional property of the seed on structural surfaces of Mild steel (MS), Plywood (PW), Concrete (CC) and Glass (GL) is a parameter which needs to be measured. In this study, the static coefficient of friction of two Nigerian beniseed accessions (Yandev-55 and E8) were determined at moisture content levels of 5.3, 10.6, 16.1 and 22.4 per cent (wet basis). These were used as inputs into designing a beniseed oil expeller. A - 2 x 4 factorial experiment in completely randomized was used for the study. The static coefficients of friction between beniseed and the four structural surfaces increased curvilinearly with increase in moisture content irrespective of the surface employed. The result showed that glass has the least value of 0.32 while for mild steel, plywood and concrete, frictional coefficients with beniseed were between 0.39 to 0.59 within the 5.3 and 22.4% moisture content levels. The effect of moisture content is highly significant on the coefficient of frictions of all the tested surfaces..

Keywords: Coefficient of friction, Beniseed, Structural surface, Moisture content.