Expandable Cartridge Heaters

At any given temperature the maximum watt-density that can be applied to a conventional cartridge heater depends on the clearance between the cartridge and the insertion hole of a die or a mold. The larger the clearance the less efficient is the heat transfer from the cartridge to its surrounding. Excessive clearances might cause premature failures Expandable cartridge heaters are made for insertion holes that through wear has become oversized or intentionally are made larger than acceptable tolerances to facilitate the removal of failed cartridges.

Expandable cartridge heaters have two legs that are joined together at the tip. The two legs are made from single tubular heater that has a semicircular cross-section. When Expandable heaters energize, the two semicircular legs expand with respect each other and press against the insertion hole wall.

1 - Energized Standard Cartridge Heaters
2 - Unenergized Expandable Cartridge Heaters
3 - Energized Expandable Cartridge Heaters

Available Diameters Tolerances and Limitations
Nominal Diameters 0.25" 0.375" 0.5" 0.625" 0.75" 1"
Actual Diameters (+/- 0.003") 0.245" 0.370" 0.495" 0.620" 0.745" 0.995"
Max Insertion Length 18" 36" 48" 72" 72" 72"
Min Insertion Length 2" 2" 2.5" 3" 5" 8"
Maximum Voltage 240V 240V 240V 480V 480V 480V
Wattage Tolerance +5 / -10%
Length Tolerance +/- 3% up to 24", +/- 2% above 24"

Typical Heating Applications

  • Plastic Molding
  • Packaging Equipment
  • Plastic Extrusion
  • Labeling Machines
  • Platens and Dies
  • Hot Stamping

Terminations and Mounting Styles

A1 Style

High temperature fiberglass leads straight

A3 Style

Right angle high temperature leads

K1 Style

SS braided high temperature leads

K2 Style

Right angle SS braided high temperature leads

X1 Style

High temperature leads with armor cable

X2 Style

Right angle high temperature leads with armor cable

PT Style

Screw terminals

FL Style

Flange mounting attachments or stop rings