How do dryer sheets get rid of static electricity?

When clothes tumble inside a dryer, friction causes an exchange of electrons on the surface of the fabric. Items that acquire excess electrons become negatively charged while those that lose electrons become positively charged. The differently charged fabric attracts and clings together, which can make it hard to pull apart for folding and may also cause a mild electrical shock, commonly referred to as static cling. Dryer sheets are coated with positively charged chemicals that rub off on the clothes in the presence of heat. With the clothes positively charged, they don't stick together.

Chemicals on the sheets can also act as lubricants, which make clothes feel softer and more flexible. This can make clothing easier to iron and care for. Wrinkling can also be decreased because the items are softer and have less static cling.