Question

Polyester fibre is manufactured by the process of:

• A. Wet spinning
• B. Dry spinning
• C. Melt spinning
• D. Gel spinning

Hint:

Most synthetic fibres like polyester and nylon are produced by melt spinning due to its efficiency and solvent-free nature.

Answer 1

The Correct Option is C

The question asks about the process used to manufacture polyester fibers. Let's explore the options:

• Wet spinning: This process involves dissolving the polymer in a solvent and then extruding it into a coagulating bath. It is commonly used for fibers like acrylic and rayon.
• Dry spinning: In this process, the polymer is dissolved in a volatile solvent and extruded into a heated chamber where the solvent evaporates. It is used for fibers such as acetate and spandex.
• Melt spinning: Here, the polymer is melted and extruded through a spinneret. As the fibers emerge, they are cooled to solidify. This process is used for polymers that can be melted, such as polyester and nylon.
• Gel spinning: This technique involves spinning a polymer solution or gel. It is mainly used for high-performance fibers like aramid and ultra-high-molecular-weight polyethylene.

The correct answer is Melt spinning, which is widely used for manufacturing polyester fibers. Polyester, being thermoplastic, can be easily melted and extruded through spinnerets to form fibers, cooled, and solidified. This makes melt spinning the most efficient and economical method for producing polyester.

To conclude, polyester fibers are manufactured using the melt spinning process due to their thermoplastic nature, which allows them to be melted and shaped into fibers.

Answer 2

Step 1: Understanding fibre manufacturing processes.
Man-made fibres are produced by converting polymers into filaments using different spinning techniques. The choice of spinning method depends on whether the polymer can be melted or must be dissolved.
Step 2: Nature of polyester polymer.
Polyester is a thermoplastic polymer. It can be melted without decomposition and solidified again on cooling, making it suitable for melt-based processing.
Step 3: Explanation of melt spinning.
In melt spinning, the polymer is melted and extruded through spinnerets to form filaments. These filaments solidify upon cooling and are then drawn to improve strength and orientation.
Step 4: Analysis of options.
(A) Wet spinning: Used for polymers that cannot be melted, such as viscose rayon.
(B) Dry spinning: Used for polymers dissolved in volatile solvents, such as acetate fibres.
(C) Melt spinning: Correct — Polyester is manufactured using melt spinning.
(D) Gel spinning: Used for ultra-high molecular weight polymers like high-performance polyethylene fibres.
Step 5: Conclusion.
Since polyester can be melted and extruded without chemical degradation, melt spinning is the most suitable manufacturing process.