| 摘要 |
<p>In a dry forming system for laying out a fibrous layer on a forming wire (2) a perforated pipe (12) is used, which extends crosswise over the forming wire, and through which is passed a flow of air fluidized fibers. Inside the pipe (12) is arranged a rapidly rotating needle cylinder (34), the needles (36) of which exert a transverse carding action on the fibers. For enabling a laying out of long fibers or a mixture of both long and short fibers the pipe (12) is provided with oblong perforations (50), which should, surprisingly, be oriented in the longitudinal direction of the pipe for giving rise to a considerable fiber discharge capacity. An admixture of short and long fibers may be supplied from a mixing unit, to which is fed separate air fluidized fiber flows from individual defibrators for optimally defibrating pulp materials of short and long fibers, respectively.</p> |
