Drying twist test is important test for fiber identification. Here, fiber is identify by the direction of twist. Fiber could be twisted in clockwise or anti-clockwise direction. By observing the twist direction we can identify the fiber types.
Procedure of Drying Twist Test: Here, I have given a drying twist testing procedure. Drying twist test is performed as the following way.
- At first, few parallel fibers are separate out.
- Then, fiber is making wet thoroughly by dip in the water.
- Excess water is removed with the tissue or by squeezing.
- Tap the end of the bundle to make separate fibers flare out.
- Free end is holding over a hot plate in warm to dry the fibers.
- Hold the fibers so that the free ends point is easy to observe by the observer.
- Then, note the direction of twist as the fibers dry.
- After observing the twist direction, we can give a result
- If twist direction is in a clockwise then they are Linen, Ramie, and Nettle.
- If twist direction is in anti-clockwise then it is Hemp and most of the fibers show the same twist direction.
- If twist direction is in alternating clockwise and anti-clockwise then it is Cotton fiber.