Explain the manufacture of viscose rayon. Add its properties and uses.

1. 1 · Open in two lines. Viscose rayon is a regenerated cellulosic fibre made from wood pulp. It was the first man-made fibre, once called artificial silk.
2. 2 · Draw the flow chart. [Flow chart: wood pulp → steeping → pressing and shredding → ageing → xanthation → dissolving → ripening → spinneret → acid bath → washing and drying → filament or staple]
3. 3 · Preparing alkali cellulose.
   • Steeping in about 18% caustic soda.
   • Pressing and shredding into crumbs.
   • Ageing to shorten the chains.
4. 4 · Making viscose.
   • Xanthation with carbon disulphide (orange xanthate).
   • Dissolving in dilute caustic soda; ripening, filtering, removing air.
5. 5 · Spinning and finishing. Wet spinning through spinnerets into a sulphuric acid bath regenerates cellulose; filaments are stretched, washed, bleached, dried and cut or wound.
6. 6 · Properties.
   • Highly absorbent, soft, drapes well, dyes brightly.
   • Weak, much weaker when wet; creases.
   • Does not melt; burns like cotton; mildew possible.
7. 7 · Daily-life link. Cool saris, kurtas and linings; also wipes and sanitary products. Wash gently and never wring.
8. 8 · Close in one line. Viscose gives cotton-like comfort with silk-like drape at low cost, but needs gentle handling when wet.

Scoring tip: Learn the eight steps with the mnemonic and draw them as a flow chart; that alone covers half the marks.