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The stain test is another chemical test for the fiber identification process. Besides, I have already written about the solubility test which is a chemical testing method. It is a textile fiber chemical test methods. This type of test shows the natural shades of the fiber. All the fibers do not have the same natural color which can be found out by treating the fibers with a drop of zinc chloro-iodide reagent.
Sequence Of Stain Test To Identify The Textile Fibers
Here, I have described the procedure of stain tests to identify the textile fibers. The stain test is used to identify the textile fiber. The following is the sequence of chemical stain tests for identifying the textile fibers. The flow chart of stain test of fibers are:
- At first, different natural fibers are taken for the test.
- A few fibers are placed on the microscopical slide.
- A drop of zinc chloro-iodide reagent is applied to the fiber and covered with a coverslip, taking care to avoid bubbles.
- Examine the fibers for staining.
- By observation, we will find the following results:
- Hemp, Ramie, and cotton stain violet.
- Flax stain is brownish violet.
- Jute stains brown.
- Many other fibers stain shades of yellow-brown, including silk.
- Warm a few fresh fibers on a microscopical slide with a drop of Phloroglucinol reagent.
- Woody fibers such as unbleached jute stain deep magenta because of the presence of Lignin.
So, after observing the test sample, we can decide about the fiber. It is the most common process to determine the natural shade of fiber. Also, we can carry out density tests, drying twist tests, and others to identify the fibers.
Textile fibers play an important role in the apparel or clothing industry. Besides, different textile fibers have various chemical compositions and differ in their physical and chemical properties. The color of the fiber also depends on the country where it is grown, the soil in which it grows, and the region from which it is collected.
Finally, it needs to perform a stain test to be sure about the color of the fiber. That’s all about identification of textile fibers by stain test.