A sealing machine, commonly referred to as a heat sealer, is a device that seals the edges of a box or bag using heat and pressure. Heating elements produce the heat, and a set of rollers apply the pressure. The two jaws of the sealing device—one fixed and one movable—come together to form the seal. The machine is turned on to apply the heat and pressure after the box or bag is positioned between the jaws. The pressure forces the melted plastic or other material to fuse together to form a tight seal once the heat has melted it. In the same manner, the sealing machine can also cut the box or bag. One might alter the sealing procedure to suit the specific material and thickness of the package or bag being sealed.