Silicone Rubber Heater
Silicone rubber heater from Sinomas make it possible to achieve very flexible and reliable heating solutions. Flexible not only represents the physical property of the products, but also the options you have for the silicone rubber heater design. You can get fully customized silicone heaters which you can specify supply voltage, watts, dimension or even 3D geometry, installation method, thermal insulation, temperature control method, etc. Your devices will be heated exactly as you wish.
Silicone rubber heater can be made with etched foil heating elements or wire wound heating elements. Wire wound elements are wired manually according to pre-defined meander. The productivity and wiring accuracy highly depend on the skill of the workers. Unless for irregular shaped 3D profiles or long heating tapes, wire wound technology has been phased out at Sinomas.
The etched foil silicone rubber heater has exceptional heat transfer compared to wire wound heaters due to its large flat conductor surface. It can deliver more even heat profiles with higher watt density, providing longer service life. It can also be zoned with variable wattage or separate heating circuits to accommodate load variations.
Dual Voltage and Three Phase Heater PAD
Due to the flexibility in circuit design of etched foil heating element, multiple circuits can be designed to suit dual voltage supply (same wattage output) and multiple heat zones. On dual voltage silicone heating pad, with three leads, including a common in a different color, are provided for wiring the heaters in series for the higher voltage and parallel for the lower voltage. 12V 24V and 115V 230V are most popular combinations. Multiple circuit areas can be zoned to achieve different heat profiles. Three phase circuits can also be designed for high current applications.
Through a controlled process of heat and pressure, silicone rubber heaters can be factory vulcanized onto plain or black anodized aluminum, stainless steel or other metal profiles / panels. The silicone rubber actually flows into the microstructure of the metal profile forming a permanent bond and allowing the most efficient heat transfer. The metal profiles can be manufactured by Sinomas or supplied by the customer.
With no adhesive layer present, the heat transfer rates are increased. This allows silicone rubber heaters to be designed at higher watt density and increases heater life. While the max watt density for standard silicone heater is 0.78 watts per cm2, factory vulcanization to Alunimum can support up to 3.0 watts per cm2 if the operation temperature is controlled.
Pre-formed heating sleeves and spiral heating tapes are manufactured through similar process.
Specification of Silicone Rubber Heaters
|Electrical Characteristics||Thermal Characteristics|
|Voltage rating: 0-600V, AC or DC||Max operation temperature: 250°C|
|Watt density: ≤ 0.78W/cm2||Continuous operation temperature: ≤200°C|
|Watt tolerance: ±5%||Temperature control: per requirement|
|Insulation resistance: >500M||Minimum size: 10mm x 25mm|
|Dielectric strength: 1500V/min||Maximum size: 900mm x 3000mm|
|Ground mesh: optional||Termination: Teflon cable, silicone cable, PI cable, fiberglass cable, 3 prong plug set|
|Mean lifetime: ≥100,000 hours||Thermal insulation: silicone sponge of different thickness|
Temperature Rise Curve
The figure below illustrates the surface temperature of silicone rubber heater pad with different watt density over time. The sample (1.5mm thick square shaped silicone heating pad) is hanged vertically in 20°C free air. The data is supposed to be a reference for silicone rubber heater of standard structure. This is to give you an idea how fast the heating can be at different watt densities.