SOME PHYSICAL PROPERTIES OF COTTON SEED ('VARAMIN' CULTIVAR) AT DIFFERENT MOISTURE CONTENTS

To design equipment for application in plantation, harvesting, transportation, storage and processing operations of cotton seed, the knowledge of various physical properties as a function of moisture content is important. In this research some of the physical properties of cotton seed were determined as a function of moisture content. The results show that moisture content has a significant effect on the physical properties of cotton seed such as width, geometric mean diameter, volume, thousand seed mass, angle of repose, true density and bulk density (p<0.01), and also has a significant effect on the length, thickness, projected area and porosity (p<0.05). As moisture content increased from 7.17 to 13% (dry basis) length, width, thickness, geometric mean diameter, projected area, volume, thousand seed mass and angle of repose increased, while true density, bulk density and porosity decreased. Also, moisture content has no effect on the sphericity of the seeds. The interaction effect of moisture content × surface type has a significant effect (p<0.01) on the static coefficient of friction against four surface materials, namely, stainless steel, iron, galvanized iron and aluminium.