A nickel chromium 80/20 heating element is insulated into a
mica or ceramic assembly.
Used for heating up plates, tanks or draw holes of extruders,
they can be flat, 90° or U bent. Fitted with mounting holes or slots,
they can be adapted to all complex shapes. They can be fitted with aluminized steel,
brass or stainless steel sheathes to be protected against
mechanical hazards and to ensure a good heat distribution.
Mica strip heaters (PMNB) are 2mm thick
and will fit perfectly into assemblies that are closed and protected
from splashes and outside material intrusions. They must be mounted with
a back plate for a good heat transfer. Their maximum operating temperature
is 340°C (644°F) and their Watt density should not exceed 2W/cm² (13W/in²).
Sheathed Mica Strip Heaters (PMB) are 3.2mm thick and
can be fitted with an extra plate to compensate height of heater upper fold.
They can also be mounted with a tightening back plate with insulation element to
help heat transfer and to reduce heat losses. Their maximum operating temperature
is 450°C (842°F) and their Watt density should not exceed 4W/cm² (26W/in²).
Flat Ceramic Rigid Heaters (PCR) are used up to
600°C (1112°F) with a maximum Watt density of 7W/cm² (45W/in²).
They have a longer lifespan than Sheathed Mica Strip Heaters (PMB) but are
less resistant to compressions.
Flat Aluminium or Bronze Cast Heaters , are tubular
heaters (or tubular heating elements) cast into aluminium for use up to 400°C (752°F)
or into bronze for use up to 650°C (1202°F).
They comply with higher thermal and mechanical requirements.
The user will choose this type of product when confronted with a
difficult environment and when a good heat distribution and mechanical
resistance of the heater is required. In addition, lifespan of those heaters
is longer than the one of heaters using other technologies.