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.
