The cartridge heater is a
high-quality seamless metal
tube, with electrothermal
alloy wire (nichrome wire,
ferrochrome wire) evenly
twined around the the central
axis in the tube. The gap in
it is compactly filled with
oxydic magnesia with fine
insulativity and thermal
conductivity, and the nozzle
is sealed with silica gel or
ceramics. This kind of metal
armored electrothermal
element has the function of
heating gases, molds and a
variety of liquids.
