Press for dewatering paper - has membrane between felt and paper to prevent return of water from felt to paper

摘要

A press for de-watering paper comprises a pair of rollers, or a roller and support surface, through which passes a felt (3) for de-watering the material (4). Between the felt and the material is a filter membrane (5) which on the application of high pressure permits the water to pass through, but is impermeable at low pressure. The membrane pref. is hydrophobic and has a pore dia of 0.2-4 microns. Use of membrane avoids return of water from the de-watering felt to the material.