Some physical properties of flaxseed (Linum usitatissimum L.)

Physical properties of kernels, grains, and seeds are necessary for the design of equipment to handle, transport, process and store the crop. The physical properties of flaxseeds have been evaluated as a function of seed moisture content, varying from 6.09% to 16.81% (d.b.). In the moisture range, seed length, width, thickness, arithmetic mean diameter, and geometric mean diameter increased linearly from 4.27 to 4.64 mm, 2.22 to 2.38 mm, 0.85 to 0.88 mm, 2.45 to 2.63 mm and 2.00 to 2.12 mm respectively with increase in moisture content. One thousand seed weight increased linearly from 4.79 to 5.32 gr. The true density increased with moisture content from 1000 to 1111 kg/m3 while bulk density decreased 726.6 to 555.6 kg/m3 in the range of moisture content between 6.09% and 16.81%, d.b. Also, porosity values of flaxseeds increased from 27.34 to 57.44%. The highest static coefficient of friction was found on the plywood surface. The static coefficient of friction increased from 0.537 to 1.073, 0.515 to 0.933, 0.472 to 0.975, 0.499 to 0.877, 0.544 to 0.862, and 0.472 to 0.824 for plywood, aluminium, stainless steel, galvanized iron, polypropylene knitted bag and kraft paper surfaces, respectively. The angle of repose increased linearly from 21.6° to 33.4° with the increase of moisture content.