| 摘要 |
A twin-wire web forming section in a paper machine includes a lower endless carrying wire which laps a forming roll and an upper endless covering wire which laps at least a part of the portion of the lower carrying wire which laps the forming roll. First and second substantially straight runs of the carrying wire are defined prior and subsequent to the forming roll, respectively, in the direction of travel of the lower endless carrying wire, the first straight run comprising the initial single-wire portion of a web-forming zone. An open-surfaced forming board is operatively associated with the initial single-wire portion. A headbox is disposed at the forward end of the initial single-wire portion, the longitudinal axis of which is substantially aligned with the direction of movement of the initial single-wire portion. The direction of movement of the initial single-wire portion is directed upwardly at an acute angle with the horizontal while the second substantially straight run subsequent to the forming roll is directed downwardly forming a second acute angle with the horizontal. The length and position of the twin-wire portion defined by the lapping carrying and covering wires is selectively adjustable by suitable adjustment of breast and traction rolls around which the endless covering wire is trained. |
