How does Shampoo Produce lather?

Lather or foam is nothing but a collection of tiny soap bubbles. There is always a large quantity of air trapped between the hair strands on our head.

Shampoo is made of mild soap-like material with high solubility in water. When shampoo is rubbed on the hair with water, thin soap films are formed which during rubbing traps the air present between the hair strands to form small bubbles. As there are thousands of hair strands on the scalp, copious lather is produced.