Method and apparatus for the continuous extrusion of solid articles

A method of extruding a solid composite material which comprises:

• providing a quantity of first particles of a binder material, said first particles having diameters between about 0.1 and about 250 micrometers;
• providing a quantity of second particles of a primary material having a softening temperature substantially greater than the softening temperature of said binder material, said second particles having diameters between about 0.1 and about 3,000 micrometers;
• combining the first and second quantities of particles in a substantially uniform mixture wherein said binder material is present in a amount of at least about 3% by weight of the mixture;
• extruding said substantially uniform mixture from an extruder barrel into a die of substantially uniform cross-section which cross-section is not substantially smaller than the cross-section of the inside diameter of the extruder barrel;
• heating said substantially uniform mixture within said die to a temperature substantially above the softening temperature of said binder material but to a temperature less than the softening temperature of said primary material;
• applying sufficient back pressure, from without said die, to the heated mixture within said die to convert said heated mixture into a substantially homogeneous composite material;
• rapidly cooling said composite material to below the softening point of the binder material to produce the composite material;
• and
• extruding said composite material from said die as an extruded solid composite material product.