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.
So, after observing the result we can give the identity of the fiber. Other thing is that, we can also identify the fibers by density test or solubility test.
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