The cross-sectional view of a mercerised cotton fibre under the microscope looks:

Correct option is B

The cross-sectional view of a mercerised cotton fibre appears round under the microscope. Mercerisation is a chemical treatment process where cotton fibres are treated with a concentrated sodium hydroxide solution, causing the fibre to swell and become circular in cross-section. This process enhances the fibre's lustre, strength, dye affinity, and smoothness.
Information Booster Mercerisation is widely used in the textile industry to improve the properties of cotton fabrics. During the process, the cotton fibre's natural kidney or bean shape is transformed into a round shape due to the swelling caused by the chemical treatment. The benefits of mercerisation include:
· Increased tensile strength of the fibre.
· Enhanced dye uptake for vibrant and long-lasting colours.
· Improved sheen and a smoother texture, making the fabric more attractive.
The rounded shape of mercerised cotton contributes to its improved light reflection, giving the fabric its characteristic silky appearance.
Additional Knowledge
· (a) Kidney shaped: This describes the cross-section of raw or untreated cotton fibres. Before mercerisation, cotton fibres have a kidney or bean-shaped appearance due to the collapse of the central lumen.
· (c) Trilobal: This shape is characteristic of certain synthetic fibres like nylon or polyester, designed for enhanced light reflection and softness. Cotton fibres do not have this shape.
· (d) Polygonal: This shape is typical of some natural fibres like flax, but it does not apply to mercerised or untreated cotton.