Question

How will you distinguish between cotton, wool, silk, and synthetic fabrics?
Describe how jute fiber is obtained from the jute plant.

Answer 1

Hint: Among the fabrics mentioned, cotton is a plant fiber, wool is an animal fiber, silk is a fiber obtained from silkworms and synthetic fibers like nylon and polyester are long-chain polymers made artificially by chemical reactions in industry.

Complete Answer:
(a)There are many ways to distinguish between textile fibers such as feel test, bleach test, burn test, solubility test, etc out of which burn test is the most commonly used method in daily application. Let us look at how different fabrics respond to burn tests.

Fabric	Flame color	Observations
Cotton	Yellow-orange steady flame	Flames spread to other parts as well. Smells like burning paper.
Wool	Orange flickering flame	Shrinking is seen as soon as contact with fire. Smells like burning hair.
Silk	Orange slow flame	Shrinkage is seen. Smells like burning meat.
Synthetic fabrics	Blue orange slow flame	Shrinkage is seen. Smells like burning coal tar.

(b)The process of obtaining jute from the jute plant is as follows:
The jute fiber is a long, soft, shiny bast fiber that is obtained from the stem and outer skin of the jute plant. The jute is harvested from the plant and submerged in water for a few days. This causes the stem of the plant to rot and the fibers remain. These jute fibers are then extracted from the stem of the plant by a process known as retting. Now, these fibers are further separated from the non-fibrous matter manually and it is known as stripping. After this process, the fibers can be spun into yarns and fabrics.

Note:
-Jute is the most affordable fiber and is the second most-produced fiber after cotton.
-The plant Corchorus olitorius is the primary source of jute fiber.
-Genetically modified cotton plants known as the Bt cotton were made resistant to insects by introducing the toxin gene of Bacillus thuringiensis in its genome.