| 摘要 |
In the production of cigarette filter rod from filter tow the conveyance of tow into a tow shaping unit (12, 32, 56, 76) is aided by controlling tow tension so that excessive stretch (and hence possible loss of crimp) is avoided. The tension is controlled by tow conveying arrangements upstream of the tow shaping unit and which may include air extracting devices and entraining devices (20-28), opposed tow engaging wheels (34, 36), a tow reservoir (64), a tow engaging refuser roller (70), or a tow spinning unit (74). In the tow spinning unit (74) the tow is gathered and twisted in a converging conical guide which is rotated at high speed, and which may also impart an axial thrust to the tow to aid conveyance into the tow shaping unit (76). |
