The solution left after removing the soap contains glycerol, which can be recovered by fractional distillation. To improve the quality of soaps desired colours, perfumes and medicinal chemical substances, added.
Types of Soaps
Different kind of soaps are made by using different raw materials.
1. Toilet soaps These are prepared by using better grade of fat or oil and care is taken to remove excess alkali. Colour and perfumes are added to make these more attractive.
2. Floating soaps These can be prepared by beating tiny bubbles into the product before it hardens.
3. Transparent soaps These are made by dissolving the in ethanol and then evaporating the excess solvent.
4. Medicated soaps Medicated soaps are prepared by some antiseptics like dettol or bithional.
5. Shaving soaps These contain glycerol to prevent drying. A gum called rosin is added while making them. It forms sodium rosinate which lather well.
6. Laundry soaps These sodium silicate, borax and contain sodium fillers like carbonate. sodium rosins
7. Soap Chips These are made by running a thin sheet of melted soap on a cool cylinder and scraping off the soaps in small broken pieces.
8. Soap grannules These are dried miniature soap bubbles.