Paper machine - utilises a gap-former having two wires with suspension sprayed between them and then passing over cross-rail with convex surfaces

摘要

A double wire on a paper machine is constructed as a gap-former. The suspension is sprayed into the gap between two wires or similar water extn. material. There is at least one cross-rail beneath the bottom wire for water extn.. The profile of the cross-rail begins with a convex shape and having two radii in the direction of the run of paper. The second radius is larger than the first. Pref. the two wires have water extn. from the suspension and a paper formation in direction with thickness which is compressed in the gap. At the beginning of the area of the cross-rail which has a smaller radius, the water is extracted below, in front of it, without forming ridges, or a wave which shows as a fault in the paper. The second area has a radius which is larger. There is water extn. above the top wire, which provides adequate fluid to enable the bottom wire to glide over the cross-rail. The system may be formed into a series of water extn. points on the machine. It is necessary for the return rollers for the wires to be set to give the required angle in approaching the gap former. ADVANTAGE - The first radius convex eliminates the need for a suction roll. The paper is well formed and has a satisfactory consistency. A waveform in the paper is avoided. The cross rail does not erode quickly.