Pneumatic false twist spinner - has separate clamping lines for each sliver at final pair of drawing rollers

摘要

The pneumatic false twist spinning appts., with a common drawing unit for two slivers running next to each other, has a roller structure in the final pair of the drawing unit where the lower roller and/or the pressure roller each form separate clamping lines, for each sliver, through a centre roller section of reduced dia. A suction roller is after the final pair of rollers, in the direction of sliver travel, with a faster roller surface speed than the transport speed of the slivers. A belt guide in the drafting zone, before the final pair of rollers, has belts to give a larger width than the total of the two roller clamping lines and the space between them. The two final clamping lines of the final pair of rollers each have an axial length smaller than the dia. of the lower roller, and pref. 0.9 times the lower roller dia., or 0.75 times of dia. The pressure roller of the final roller pair has a roller body with a profiled mantle to give a centre section of reduced dia., or it carries two mantles axially sepd. from each other. The lower roller also has a reduced dia. sectin between the two outer clamping lines. ADVANTAGE - The air flow behaviour at the final pair of rollers is symmetrical for each sliver, even though a single drawing unit acts on them both, with symmetrical air movement at the feed and delivery sides.