Silicone rubber heaters 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 where you can specify the supply voltage, the wattage, the dimension or even 3D geometry, the means of installation, the thermal insulation, temperature control method, etc. Your devices will be heated accurately in the pattern as you desire.
Silicone rubber heater can be made with etched foil heating elements or wire wound heating elements. The material of the heating elements can be copper, constantan, Nichrome, kanthal, etc. The specific choice depends on the resistance value of the heating element and other requirement like TCR.
Wire wound elements are wired manually according to pre-designed 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.
Etched foil silicone rubber heaters make use of thin metal foils (e.g. 0.05mm), usually nickel based alloy as the resistance element. The resistance pattern is designed in CAD and transferred to the resistance foil, which has been laminated with the insulation substrate. The element substrate is then processed through acid solution to produce the desired resistance pattern.
The etched foil silicone rubber heater has exceptional heat transfer compared to wire wound heaters due to its large flat surface area. It can deliver more even heat profiles with higher watt density, providing longer service time. It can also be zoned with variable wattage or separate heating circuits to accommodate load variations.
Dual Voltage and Three Phase Pad Heaters
Due to the flexibility in circuit design of etched foil heating element, multiple circuits can be designed to suit for dual voltage supply (same wattage output) and multiple heat zones. On dual voltage pad heaters, 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.
These options and advantages also apply to our kapton heaters.
Pre-formed Silicone Heaters and Factory Vulcanization
With our special developed tools, the silicone rubber heaters can be pre-formed to pre-defined shapes and fit the profile of your fixtures exactly. A good example is the heating sleeve for thermal transfer heat press.
We can also vulcanize silicone rubber heaters with metal profiles in house. Perfect bonding and minimum temperature variation will be ensured. Among other applications, silicone rubber heaters factory vulcanized with black anodized Aluminum plates can be used for anti-condensation heating for high voltage switchgears.
Factory vulcanization of the silicone heater is recommended for the following permanent installations:
- heaters to be installed inside or outside of a drum, e.g. heated roller for X-ray photograph processing
- heaters to be installed on complicate shaped objects, like bent or T pipes
- applications which have high requirement on temperature distribution
Moisture Proof & Grounding Mesh
Silicone rubber heaters are generally moisture proof. If higher IP class is required, please refer to the page waterproof pad heater
3 prong plug set and grounding mesh are available for extra safety. Please specify if you need.
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/min||Maximum size: 800mm x 3000mm|
|Ground mesh: per requirement||Lead exit: Teflon cable, silicone cable, PI cable, Glassfiber cable|
|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 heaters with different watt density over time. The sample (1.5mm thick square shaped silicone pad heater) 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.