Rieter

The formation of the spinning triangle

Index

Fig. 83 – Short (a) and long (b) spinning triangle, (c) side view

Fig. 84 – Spinning triangle - influence of the twist

The turns of twist in a yarn are generated at the  traveler and move contrary to the direction of yarn movement toward the  drafting system. Twist should run back as far as possible toward the nip line of the rollers, but it never reaches as far as the nip because, after leaving the rollers, the fibers first have to be diverted inwards and wrapped around each other. The twist moves up until angle κ (which is the angle of the fiber arrangement in the yarn) is equal to angle η of the spinning triangle (Fig. 84). There is therefore always a triangular bundle of fibers without twist, the socalled spinning triangle, at the exit from the rollers. By far the most end breaks originate at this weak point, because the yarn tension in the balloon can be transmitted almost without obstruction as far as the drafting system, whereas twist in the spinning triangle is zero.