PULP AND LINERBOARD FORMER WITH IMPROVED DEWATERING

摘要

PURPOSE: An inexpensive compact pressing section and a wire former with a reduced maintenance rate are provided. CONSTITUTION: In a twin wire former (20) a headbox (30) injects stock onto a forming wire (22) with which a second forming wire (24) is brought into gradual engagement. A forming shoe (40) directs the two wires along a path of increasing curvature, above which water is drained by adjustable auto slices (44, 46).The two wires (22, 24) with the web (34) therebetween then follow an oscillating S-shaped path between seven S-rolls (52) and are directed upwardly through three individually loaded press rolls (58) with increasing pressure to about four hundred and fifty pounds per linear inch at the last wet press. Drainage pans (83) collect water from the upper surface of the twin wires and water thrown off the upper press rolls. The press rolls are individually pneumatically pivotable to increase nip pressure, and collectively pivotable to open all the nips. Next a high pressure dry nip (80) can increase the fiber content of the web (34) to thirty-five percent fiber.