The movement of twist in a yarn over a surface was found to be governed by two separate mechanisms. These were designated as the flattened and rotating or leakage mechanisms. The twist blockage forces appeared to be developed gradually over the contact surface and there was some yarn rotation on the surface and often a steady loss of blocked twist. It was discovered that another important feature of the twist blockage phenomenon is that, the twist blockage behavior is highly sensitive to the relative orientation of the guide axis to the yarn, and to the direction of the yarn twist helix (S or Z).In ring spinning or false-twist is deliberately fed upstream against the flow of yarn. The upstream movement of this twist may also be blocked to a greater or lesser degree if the yarn passes over a guide or similar surface.
In ring spinning process, Downstream blockage is defined as the prevention of the transmission of yarn twist in the same direction as the yarn flow; upstream blockage is defined as the prevention of twist propagation in a direction opposite to the yarn flow.
the phenomena appears at different types of industrial textile manufacturing as waving, fabric dying... etc.
Reference
:http://www.amazon.co.uk/TWIST-CHANGES-THEARDLINES-MOVING-SURFACES/dp/3838345193
- Badges
- Science topic
- Similar topics
- Engineering
- Mechanical Engineering