The cylinder mold is designed for forming a web layer and removing it from the forming section, preliminary dewatered of the web use the open area of the cylinder and rider roll .After that the web is subsequent transferred to the transporting part (felt).
The cylinder is immersed in paper pulp with a concentration of 0.5 … 0.7%. The cylinder of a welded structure consists of a central tube with placed rings with cutouts for firegrate bars. A wire diametr of 2 mm is wound on top of the firegrate bars.
A cylinder mold has an several advantages comparing with a fourdrinier
• the wire surface is used more efficiently in forming process, the index of usage of the wire surface for cylinder mold is 0.6-0.7 compared to 0.4-0.45 for fourdrinier;
• the formation of a layer on a cylinder mold proceeds under a relatively large hydrostatic head (0.1-0.3 m of water column) comparing with on a wire fourdrinier , where the hydrostatic head is at the beginning part of the fourdrinier and is equal to the thickness of the water-fiber layer on the wire;
• the cylinder mold has no shaking mechanism that simplifies the design;
• a cylinder mold takes up a little space, is simple and cheap to manufacture that was a valuable quality and determined its dominant application in the cardboard machines that produce multilayer cardboard.