Abstract :
Some physical properties of delinted and bare cotton seed were evaluated as a function of moisture content. The average length, width and thickness of seeds ranged from 9·02 to 9·19, 4·70 to 4·86 and 4·25 to 4·45 mm as the moisture content increased from 8·33 to 13·78% dry basis (d.b.), respectively. In the same moisture range, studies on rewetted cotton seed showed that the sphericity increased from 0·626 to 0·635, the seed volume from 95·4 to 109·6 mm3, thousand seed mass from 104·06 to 109·64 g, projected area from 35·89 to 40·14 mm2 and the terminal velocity from 8·46 to 8·67 m s−1. The static coefficient of friction of cotton seed also increased linearly on four structural materials, namely, stainless steel (0·27–0·35), galvanized iron (0·38–0·41), plywood (0·39–0·42) and rubber (0·42–0·44). The bulk density decreased from 642 to 610 kg m−3, true density from 1091 to 1000 kg m−3, porosity from 41·16 to 39·00% and the shelling resistance from 65·0 to 50·2 N.
