Question 18 (Textile Engineering & Fibre Science)
The ratio of wet-strength to dry-strength of visocse fibre is
| (A) | Equal to one |
| (B) | Always less than one |
| (C) | Always greater than one |
| (D) | Sometimes greater and sometimes less than one |
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Frequently Asked Questions | FAQs
Why wet strength of viscose is less?
Viscose is a type of rayon, which is made from cellulose fibers derived from wood pulp or other natural sources. Viscose fibers are not inherently strong and are prone to breaking when they are wet. As a result, viscose fibers have lower wet strength compared to other types of fibers, such as cotton or polyester.
There are several reasons why the wet strength of viscose is less:
Chemical structure: Viscose fibers have a relatively simple chemical structure, consisting of long chains of cellulose molecules. These chains are easily broken down by water, which weakens the fibers and reduces their strength.
Production process: The production process for viscose fibers involves several steps, including spinning, washing, and drying. Each of these steps can affect the strength of the fibers, particularly their wet strength. For example, the washing process can remove some of the natural impurities in the fibers, which can weaken them.
Fiber properties: Viscose fibers have a relatively low degree of crystallinity, which means they are less tightly packed than other fibers, such as cotton or polyester. This makes the fibers more susceptible to breaking when they are wet.
Despite its lower wet strength, viscose is still widely used in the textile industry because of its softness, drapability, and luster. Manufacturers can improve the wet strength of viscose fibers through various techniques, such as crosslinking with chemicals or blending with other fibers that have higher wet strength.