Paper machine for the manufacture of a multi-layer paper web

Abstract

A paper machine forming section with two wire forming units. One of the two forming units is a twin wire web forming unit having a headbox, two wire loops arranged in sandwich-like manner and a drainage element for each of the wire loops. The first web-forming unit has a first section including a curved suction drainage element or roll in the first lower wire loop; a second section with opposing drainage ledges, wherein the drainage ledges are stationary on the upper side and the drainage ledges are developed resiliently pressable on the bottom side; the drainage ledges of the upper and lower sides are arranged staggered with respect to each other in the direction of travel of the wire, and at least the ledges of the upper side are developed with suction; a third section which has at least one suction wire separating element on one side. The second web-forming unit is a hybrid former with a single wire. The guide rolls for the second wire of the first former and for the wire of the second former guide them on a joint wire path where the multilayer web is transferred to the wire of the second former. There is a headbox associated with the wire of the second former. A respective backwater circuit collects water and materials drained from each of the forming units and returns them to the respective headboxes.