Polymer Equipment Designs: Drying & Dewatering Presses Dewatering Screw Press Dewatering Screw Presses are designed to accept a free-drained feed material in a 40-60% water content range and dewater the material by expression to a discharge moisture in the 6-12% range. Super Dewatering PressTM Our Super Dewatering Press™ can dewater a synthetic rubber crumb from 60% inlet to a discharge moisture as low as a 3-5% range with one machine. The discharge material is cut into a porous pellet form that can be easily dried in a hot air type dryer. Mechanical Dryer Mechanical dryers normally will dry material that has been first dewatered to an 8-12% moisture by a mechanical screw press or expeller. Drying is accomplished by heating the polymer under pressure and then subjecting it to a flashing stage where the water is evaporated.