High Resistance Tubular 5mm Cartridge Heater Description for cartridge heater Classical structure of cartridge heater (Popular structure) is same to the heating tube, Generally consists of five parts: Insulator, sealing material, leading rods, filling material, electric wire, a metal protective tube, terminal. Coil electric wire and leading rod are set in the metal protective tube. manufacturing process : put coil heating wires through the seamless steel pipe, copper or aluminum tube, Using filling machine more to fill insulation and thermal oxidation object evenly in the gaps,such as Crystal magnesium oxide powder (alumina or clean quartz sand are all available) etc.,And then use shrink tube machine contract pipe diameter, make oxide medium dense(make density achieves above 3.3 g/cm3),Ensure the heating wire cut off from the air, the center position touch pipe wall and don’t offset. It can increase heating power more than ten times per unit area. the using life can be i...