Importance and factors of twist in roving frame:
A slight twist is imparted from the front roller of the roving frame to hold the light thin parallel fiber weave. By imparting a twist to the parallel fibers the fibers hold each other. Moreover, the roving does not tear easily from the bobbin, is easy to transfer, and is suitable for feeding to the next machine. The slight twist imparted to the roving can be untwisted before entering the main drafting zone of the next machine i.e. the ring frame to bring the twist into a normal parallel fiber wave. https://bdfabric.com/roller-setting-and-drafting-in-the-roving-frame/
The fibers of the roving lie side by side in parallel. The method of holding these side-by-side fibers by twisting the fibers slightly to hold them together is called a twist.
Importance of roving twist:
Importance and factors of twist in roving frame. Providing a twist in roving is very important for the following reasons.
1. The fibers are delivered in a parallel position from the front roller of the roving frame. The twist is very important to hold the fibers in the roving together.
2. The roving of roving frame needs to be twisted so that it does not tear easily from the bobbin.
3. Roving bobbins are easier to make when the roving is twisted.
4. Roving is easier to transfer when twisted.
5. Twist is essential to prevent the fibers from unraveling easily from the roving and to hold small or coarse fibers easily.
6. Due to imparting twist, the roving is shaped like a yarn.
7. Due to imparting twist fiber wastage is less and easy to feed to the next machine i.e. spinning frame.
Factors of twist in roving:
Roving twist depends on the following factors:
1. Staple length of fiber:
The roving twist is dependent on fiber length. The longer the fiber length the higher the number of roving twists for a given count.
2. Hank of roving:
Depending on whether the delivered roving of the roving frame is thick or thin i.e. the roving hang. The longer the roving hang, the greater the amount of twist.
3. Fineness of fiber:
Roving twist also depends on fiber fineness. The finer the fibers, the fewer the number of twists.