Polymer fibre spinning methods: dry spinning is typically used for which fibres among the following?

Introduction / Context:Fibre spinning methods include melt, wet, and dry spinning. The choice depends on polymer thermal stability and solubility. In dry spinning, a polymer solution is extruded into a chamber of warm gas; the solvent evaporates, leaving solid filaments.

Given Data / Assumptions:

• Polymers that decompose before melting or that dissolve in volatile solvents suit dry spinning.
• Rayon (viscose) is classically wet-spun (coagulated in a bath).
• Polyethylene is melt-spun.

Concept / Approach:PVC can be formed into fibres by dry spinning from suitable solvents because it cannot be conventionally melt-spun due to thermal degradation near its processing window. Rayon (viscose) uses a coagulation bath (wet spinning), not dry spinning. PVAc may be solution-spun in niche conditions, but PVC is the textbook answer.

Step-by-Step Solution:Eliminate melt-spinnable polyethylene.Eliminate viscose rayon (wet-spinning/coagulation route).Select PVC as the standard dry-spinning example.

Verification / Alternative check:Process descriptions for acrylics, acetates, and PVC often include dry spinning; viscose relies on wet coagulation chemistry.

Why Other Options Are Wrong:Polyethylene is melt-spun; rayon is wet-spun; PVAc is less common as a fibre and not the canonical example.

Common Pitfalls:Assuming all solution-spun fibres are dry-spun; confusing dry with wet coagulation steps.

Final Answer:Poly(vinyl chloride) (PVC)