Question

The technique used for producing viscose rayon is

• A. Melt spinning
• B. Wet spinning
• C. Dry spinning
• D. Dry-jet wet spinning

Hint:

Wet spinning is used for fibres such as viscose rayon, where the fibre is extruded from a solution and solidified in a coagulating bath.

Answer 1

The Correct Option is B

Viscose rayon is a type of regenerated cellulose fibre, and the process used to produce it is called wet spinning. In this process, cellulose is first dissolved in a solution of sodium hydroxide and carbon disulfide to form viscose. This viscose solution is then extruded through a spinneret into a coagulating bath, where the cellulose is re-formed into solid fibres.

Step 1: Understand the spinning processes.
- Melt spinning involves extruding a polymer that is already in a molten state, which is used for materials like nylon and polyester.
- Wet spinning, on the other hand, involves dissolving the raw material (like cellulose) in a solvent and then extruding it into a bath where the solvent is removed, leaving behind the solid fibre.
- Dry spinning is used for polymers that are dissolved in a solvent that evaporates upon extrusion, such as acrylic fibres.
- Dry-jet wet spinning is a variation of the wet spinning process where the filament is exposed to air before entering the coagulation bath, which is not the process used for viscose rayon.

Step 2: Conclusion.
Viscose rayon is produced using the wet spinning process.

Final Answer: \[ \boxed{\text{Wet spinning}}. \]