KnowHOW team explains: To make cooking ware non-sticking, certain special chemicals are coated on the inner surface of the utensils.

The chemical popularly known as teflon is actually a brand owned by the US company DuPont. The slippery coatings of a non-sticking surface is a polymer, or a chemical chain, of a fluoride and additives such as carbon and hydrogen or polytetrafluorethylene (PTFE). This does not stick to anything but itself. It chemically resists any type chemical interaction. To coat teflon on the inner surface of a frying pan the surface is roughened by sandblasting, or blasting its surface with grit, gouging little pits in the aluminium layer, or by spraying the cookware with a micro-lumpy ceramic coating.

This helps in stronger binding of the coating to the target surface. A special coating of a glue-like substance, called a primer, is then applied on the surface. The teflon particles are embedded in the primer which forms a matrix. The coatings are fused at high temperatures. Particles of teflon migrate to the surface and get fixed. This, while cooking, doesn’t allow anything ? including a fried egg ? from sticking to the coating.

With newer non-stick surfaces, a three-coat process is used. The primer forms a chemical bond with a clean aluminium surface that is free from oxide of salts. This makes the surface tougher and smoother.

The second coat is mostly teflon; it controls the movement of these particles. The topmost coat is of clear teflon that sticks to the teflon particles of the midcoat.

The question was sent by C.P. Prahlad from Jamshedpur