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Silicone Rubber Heater

silicone rubber heaterUL & CE approved silicone rubber heaters from Sinomas make it possible to achieve very flexible yet reliable heating solutions. Flexible not only represents the characteristics of the products, but also the freedom you have for the silicone rubber heater design. You can get fully customized heaters where you can specify the input voltage, the wattage, the dimension or even 3D geometry, the means of installation, the thermal insulation, temperature control method, etc. Your device will be heated accurately in the pattern as you desire.

Heating Element

Silicone rubber heater can be made with etched foil heating elements or wire wound heating elements.

Etched foil heating elementEtched foil silicone rubber heaters are made with thin metal foils (0.02mm), usually nickel based alloy, as the resistance element. The resistance pattern to be etched is designed in CAD and transferred to the foil, which is laminated to the insulation substrate. The element substrate is then processed through acid spray to produce the desired resistance pattern.

Low voltage heaters often mean low ohm value. Very thin copper foil will be used in these cases. The operation tempeature should not be very high, e.g. below 100°C. otherwise the copper foil may burn out at high temperature. 

Wire wound elements for silicone rubber heaters are relatively old technology. They are wired manually according to certain patterns. The productivity and wiring accuracy highly depend on the skill of the workers, especially for small sized heaters. Unless for irregular shaped 3D heating applications, wire wound technology has been phased out at Sinomas.

The etched foil silicone rubber heater has exceptional heat transfer compared to wire wound elements, due to its large flat surface area. It can deliver more uniform heat profiles with higher watt density, providing longer service time. It can also be zoned with distributed wattage or separate heating circuits to accommodate load variations. Edge compensation for the temperature distribution can also be achieved.

Dual Voltage, Zoning and Three Phase

Dual Voltage, three phase input for silicone heaterdual voltage silicone rubber heatermultiple heat zone silicone heater

Due to the flexibility in circuit design of silicone rubber heaters, multiple heating circuits can be designed to accommodate dual voltage supply (same watts output) and multiple heat zones. On dual voltage heaters, three leads, including a common in a different color, are provided for wiring the heater in series for the higher voltage and parallel for the lower voltage. 12V 24V 48V (DC) and 115V 230V (AC) are most popular combinations. Multiple circuit areas can be zoned to achieve different heating profles. Three-phase circuits can also be designed for high current applications.

These options and advantages also apply to our kapton heaters.

Waterproof Silicone Rubber heater

waterproof silicone heaterWe have developed waterproof silicone rubber heaters which can be immersed into water for long operation. This is very useful for high humidity environment or fluid heating where conventional immersion heaters can't be installed due to space or mounting limit. For example we have delivered thousands of silicone heating elements for waterbags to keep people warm in winter and as pad heaters to warm the plant vase in greenhouse.

The applicable fluid includes some corrosive chemical solution. Our silicone rubber heaters have been used for SCR (Selective Catalytic Reduction) tank Adblue heating for exhaust gas emission control of diesel engine vehicles. Please consult us for chemical compatibility if you have similar demand.

Specification of silicone rubber heaters

Electrical Characteristics Thermal Characteristics
Voltage rating:   0-480V, AC or DC Max operation temperature:  250°C
Watt density:  ≤ 5.0W/cm2 Continuous operation temperature:  ≤200°C
Watt tolerance:  +/-5% Temperature control:  per requirement
Insulation resistance:  >500M Minimum size:  10mm x 25mm
Dielectric strength:  1500V/s Maximum size:  800mm x 3000mm
Ground mesh:  per requirement Termination:  Teflon cable, silicone cable, PI cable
Mean lifetime:  ≥100,000 hours Thermal insulation:  optional, silicone sponge of different thickness


Factory Vulcanization

silicone rubber heaterpreformed silicone rubber heaterpipe fitting of silicone rubber heater

Factory vulcanization of the silicone rubber heater is recommended for the following permanent installations:

  • heater to be installed inside or outside of a drum (e.g. mug heater)
  • heater to be installed on complicated shaped objects, like bent or T pipes
  • applications which have high requirement on temperature distribution

With our special developed tools, the silicone rubber heaters can be preformed to a certain shape and easily attached to your equipment without extra work. Minimum temperature variation will be ensured.

We delivery many standard silicone rubber heaters (often with power plug) factory vulcanized with Aluminum plates as anti condensation heaters.

Temperature rise curve

The figure below illustrates the surface temperature of 1.5mm thick silicone rubber heaters with different watt density over time. The heater is hanged vertically in 20°C free air. The data is supposed to be a reference for 1.5mm thick silicone rubber heater of standard structure. This is to give you an idea how fast the temperature rise can be. 

temperature rise curve of silicone rubber heaters