Moisture-Dependent Physical Properties of Sunflower (SHF8190)

Physical properties are very important in design and manufacturing of harvest and post harvest machines. In this research some physical properties of sunflower seeds (SHF8190 variety) were determined as a function of moisture content in the range of 4-22 % wet basis (w.b.) using standard techniques. The average length, width, thickness, geometric mean diameter, equivalent diameter, arithmetic diameter, sphericity, surface area and angle of repose ranged from 12.14 to 12.57 mm, 5.79 to 6.38 mm, 3.86 to 4.09 mm, 6.47 to 6.85 mm, 6.56 to 6.97 mm, 7.27 to 7.61 mm, 53.33% to 55.42%, 112.16 to 125.01 mm2 and 41 to 57° as the moisture content increased from 4% to 22% w.b., respectively. The thousand grain weight (TGW) increased from 80.3 to 96.8 g whereas the bulk density decreased from 410 to 380 kgm-3 and the true density from 740 to 980 kg m-3 with an increase in the moisture content range of 4–22 % w.b.The data of sunflower seeds showed that the porosity ranged from 44.59 to 61.22%. The static coefficient of friction of sunflower seeds increased linearly against different surfaces of structural materials, namely, plastic (0.29–0.55), plywood (0.36–0.53), and galvanized iron (0.36–0.55) and the static angle of repose increased from 41º to 57º, respectively when the moisture content increased from 4 % to 22% w.b.