Silicone Rubber Heater Specifications and Tolerances

Performance Ratings

Maximum Operating Temperature:

  • 500°F / 260°C Intermittent
  • 392°F / 200°C Continuous

Minimum Operating Temperature: -70°F / -56.6°C

Physically Resistant To:

  • Moisture
  • Ozone
  • Fungus
  • Radiation

Agency Approvals: UL File #E65652 (wire-wound only)

Electrical Ratings:

Resistance Tolerance:

  • Wire:+10%, -5%
  • Foil:+10%, -10%

Maximum Operating Voltage:

  • Wire:600 VAC
  • Foil:480 VAC

Dielectric Strength: 1000 VAC

Standard Leads: 10″ Teflon® Insulated Stranded Wire

Maximum Resistance Density for Heaters with Etched Foil Element: 125 Ω/in2

Construction Types

Wire Wound Element:

  • Consists of resistance wire wound on a fiberglass cord for added support and flexibility
  • Element can be laid out in a special designed pattern to fit application requirements such as:
    • ensure uniform heat profile or to concentrate the heat profile in a specific section(s) of the heater
    • conform to the size and shape of the silicone rubber heater
    • avoid holes and cutouts
  • Power lead wires or cord sets are attached to the heater windings with solder and firmly secured in place through a vulcanizing process, ensuring that the assembly becomes homogenous
  • Recommended/preferred for small to medium size quantities, medium to large size heaters, and to produce prototypes to prove out the design parameters prior to entering into large volume production runs when using etched foil
  • Provide excellent physical strength capable of withstanding repeated flexing without compromising the life and performance of the heater
  • Very effective for manufacturing geometrically challenged shapes, including three dimensional ones

Etched Foil Element:

  • Made with a thin metal foil (.001″), usually a nickel base alloy, as the resistance element
  • Resistance pattern to be etched is designed in CAD and transferred to the foil, which is laminated to the insulating substrate; the element/substrate is then processed through an acid spray to produce the desired resistance pattern; the top layer is then added and vulcanized
  • Lead wires are then attached to the heater and insulated with additional silicone rubber to complete the heater
  • Has exceptional heat transfer compared to wire wound elements, due to its large flat surface area.
  • Can deliver more uniform heat profiles with higher watt densities, providing longer operating heater life
  • Can also be zoned with distributed wattage or separate heating circuits to compensate for load variations
  • The etched foil process is recommended for small size heaters in large quantities.

Physical Size and Construction Limitations

Maximum Size:

  • Wire:36″ × 144″ (91.4 × 366 cm)
  • Foil:10″ × 22″ (25.4 × 56.9 cm)

Dimensional Tolerance:

  • Less than 6″: ±0.030″ (0.76 mm)
  • 6″ to 12″:±0.060″ (1.52 mm)
  • 12″ to 18″:±0.125″ (3.17 mm)
  • 18″ to 36″: ±0.250″ (6.35 mm)
  • 36″ to 72″:±0.500″ (12.7 mm)
  • Every 36″ after 72″:Additional ±0.250″ (6.35 mm)

Nominal Thickness:

  • Wire:0.056″ (1.42 mm)
  • Foil:0.030″ (0.76 mm)

Available Thickness: 0.018″ to 0.112″ (0.46 mm to 2.85 mm)

Weight: 7 oz./ft2 (0.21g/cm2)