Minimum Volume Pressing of Greasy Wool

Abstract

Greasy wool preheated to 90°C can be compressed in one press minute to over 1000 kg/m³ using about one-third of the pressure needed at ambient temperatures, and then cooled out-of-press to give long-term stability of compressed density similar to that obtained by maintaining the pressure during in-press heating and cooling. Minimum total volume, the actual volume of wool plus contaminants with air excluded, can almost be achieved at pressures below 5 MPa. At higher pressures, product volume is reduced by the volume of extra grease squeezed out for recovery, resulting in a higher wool yield product of lower weight.