Textile Fibres and Yarn Quiz: Cotton, Silk, Polyester and Viscose

Three families of fibre

• Natural fibres come from plants (cotton, linen, jute) or animals (silk, wool). Plant fibres are cellulose; animal fibres are protein.
• Regenerated fibres such as viscose (rayon) and modal are made by dissolving natural cellulose, usually from wood pulp, and spinning it back into fibre.
• Synthetic fibres such as polyester, nylon and acrylic are made from petrochemicals. Most polyester is PET, the same material as plastic bottles; recycled polyester is made from used PET.

The polyester yarn chain in Surat

Surat's weaving industry runs largely on polyester filament yarn. Spinning plants produce POY (partially oriented yarn). Texturisers draw and crimp it into PTY (polyester texturised yarn), which gives the fabric a softer, fuller hand. FDY (fully drawn yarn) is a smooth filament yarn used directly in weaving. Weavers turn these yarns into grey fabric for the process houses.

Denier and count: how fine is the yarn?

• Denier is the weight in grams of 9,000 metres of yarn. Lower denier means finer yarn. It is used for filament yarns such as polyester and nylon.
• Cotton count (Ne) is the number of 840-yard hanks in one pound of yarn. Here it works the other way: a higher count means finer yarn, so 40s is finer than 20s.

Choosing by comfort and use

Cotton and viscose absorb moisture and feel cool, which suits Indian summers. Polyester is strong, cheap, wrinkle-resistant and dries fast, but absorbs little sweat. A small share of elastane (Lycra, spandex) adds stretch and recovery. Blends such as poly-cotton or poly-viscose combine these qualities.

Fibres and yarns are taxed at 5% GST. Check the HSN code for any yarn in the yarn and fibre HSN finder.