A METHOD FOR FORMING A WEB FROM AEROSUSPENSION OF FIBROUS MATERIAL

摘要

A process and an apparatus for making paper by an aerodynamic method. An aerosuspension is fed onto a moving forming wire positioned at an angle relative to the aerosuspension flow. Then, an air component is removed by means of a suction device located on the opposite side of the wire. The aerosuspension feed and air removal are performed in a direct-flow channel in which the value of a suction force is set to increase in the direction of the forming wire motion so that the suction force applied to the fibrous material in the surface layer of the web being formed is approximately the same along the forming wire in the web formation zone. As a result, a low fiber concentration in the aerosuspension is maintained up to the moment the suspension reaches the forming wire followed by an effective air removal featuring no vortexes in the vicinity of wire, the fibers are reliably held on the wire, and the possibility of shear of the fibers falling onto the wire is excluded. The above factors, combined, enable production of paper with a high degree of uniformity at a high production rate.