The heating roller is made of a seamless aluminum alloy tube with a wall thickness of 1 to 3 mm and a surface coated with polytetrafluoroethylene. To prevent the toner that melts during fixing from sticking to the roller.
The Teflon coating on the surface of the heating roller will slightly soften at high temperatures. When the printing paper is caught in the fixing device, it cannot be forcibly cut out with a sharp hard object (such as a screwdriver or a camera). It will damage the surface coating of the heat roller and affect the integrity of the toner image after fixing. But now there are many laser printers that use more advanced ceramic heaters (PCT), which have the characteristics of fast heating and power saving.