| 摘要 |
PCT No. PCT/GB83/00331 Sec. 371 Date Aug. 10, 1984 Sec. 102(e) Date Aug. 10, 1984 PCT Filed Dec. 13, 1983 PCT Pub. No. WO84/02257 PCT Pub. Date Jun. 21, 1984.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 two 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 ad 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).
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