Though it’s been around since at least the 1970s, RF welding still impresses people outside the industry with its futuristic connotations. It doesn’t seem possible to permanently fuse two materials together using the very same radio waves we use to communicate wirelessly over long distances.
RF welding passes a high-energy electromagnetic field through the two plastic sheets. The materials are designed to be “thermoplastic,” or to react in a specific way when subjected to the high frequencies required. Radio frequencies excite the molecules in both materials causing them to vibrate and, when pressed together, bond with each other at the molecular level.