The heating tube, as the heating core of the coffee machine, has a simple basic structure, but contains exquisite design wisdom. It is mainly composed of three parts: heating wire, metal tube and insulating material. The heating wire is like the "heart" of the heating tube. It is the key part for converting electrical energy into thermal energy. It is usually made of alloy materials with high resistivity. When current passes through, the heating wire will quickly heat up and provide a power source for subsequent heat conduction.