Question 37 (Textile Engineering & Fibre Science)
Consider the following Assertion [a] and Reason [r]
[a] In the case of manufactured fibre spinning, a circular spinneret orifice always results in circular cross section of filament in melt spinning, but the same in not true in dry spinning.
[r] Melt spinning involves only heat transfer, whereas dry spinning involves heat as well as mass transfer.
Determine the correctness or otherwise of the above Assertion [a] and Reason [r]
|(A)||[a] is right [r] is wrong|
|(B)||[a] is right [r] is right|
|(C)||[a] is wrong [r] is right|
|(D)||[a] is wrong [r] is wrong|
Answer / Solution
Frequently Asked Questions | FAQs
What is the difference between melt spinning and dry spinning?
Melt spinning and dry spinning are two different methods used in the textile industry to produce synthetic fibers. The main difference between these two methods lies in the state of the polymer solution used to make the fibers.
Melt spinning is a process in which a polymer is melted and extruded through spinnerets, which are small holes that can be of different shapes and sizes, to form continuous fibers. The fibers are then cooled rapidly to solidify them. Melt spinning is typically used for thermoplastic polymers that can be melted and re-melted multiple times without undergoing significant degradation, such as polyester, nylon, and polypropylene.
Dry spinning, on the other hand, is a process in which a polymer solution in a volatile solvent is extruded through spinnerets to form continuous fibers. The solvent is then evaporated to solidify the fibers. Dry spinning is typically used for polymers that are not heat-stable, such as cellulose derivatives (e.g., rayon and acetate).
The main difference between these two methods is that in melt spinning, the polymer is melted to form fibers, while in dry spinning, the polymer solution is dissolved in a solvent that is later evaporated to form fibers. Additionally, melt spinning is typically faster and less expensive than dry spinning, as it does not require a solvent recovery system. However, melt spinning is limited to thermoplastic polymers, while dry spinning can be used for a wider range of materials, including non-thermoplastic polymers.
Overall, the choice between melt spinning and dry spinning depends on the specific material and properties desired for the final product.