Explain the primary and secondary properties of textile fibres.

1. 1 · Open in two lines. Fibre properties decide whether a fibre can be made into cloth and how that cloth behaves in use. They are grouped as primary and secondary.
2. 2 · Primary properties.
   • High length-to-width ratio (about 100 : 1 or more).
   • Tenacity (strength).
   • Flexibility.
   • Cohesiveness (spinning quality).
   • Uniformity of length and fineness.
3. 3 · Secondary properties: physical.
   • Shape and surface: cross-section, crimp.
   • Lustre and specific gravity.
   • Moisture regain and absorbency.
4. 4 · Secondary properties: mechanical.
   • Elasticity and elongation.
   • Resiliency.
   • Abrasion resistance.
5. 5 · Secondary properties: chemical and others.
   • Thermal behaviour and flammability.
   • Reaction to acids, alkalis and bleach.
   • Resistance to mildew, moths and sunlight; static.
6. 6 · Draw a comparison table. [Table: cotton, wool, silk, rayon, nylon, polyester against strength, regain, wrinkle resistance and heat]
7. 7 · Daily-life link. High-regain cotton suits hot climates and hospital wear; low-regain, resilient polyester suits easy-care uniforms.
8. 8 · Close in one line. Primary properties make a fibre spinnable; secondary properties decide its comfort, care and end use.

Scoring tip: Write each property as a bold heading with one line of meaning and one fibre example. The comparison table is quick and scores well.