Patent ID: 6228220
Filing Date: 2001-05-08
Classification: D21F

Abstract:
A method for dewatering a cellulosic web using pressurized fluid, comprising:depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web;sandwiching the wet web between a pair of fluid permeable support fabrics, one of the support fabrics being the forming fabric;passing the sandwiched wet web structure through an air press comprising an air plenum and a collection device, the air plenum and collection device being operatively associated and integrally sealed such that about 70 percent or greater of the pressurized fluid supplied to the air plenum passes through the wet web;positioning cross-machine direction sealing members to deflect the course of travel of the wet web and support fabrics toward the collection device such that the cross-machine direction sealing members impinge into the support fabrics;supplying the pressurized fluid to the air plenum to create a pressure differential across the wet web of about 25 inches of mercury or greater;transporting the wet web through the air press at industrially useful speeds to provide a dwell time of about 10 milliseconds or less; anddrying the web to a final dryness.