Polyimide Heater vs Silicone Rubber Heater: Which is Better?

When you’re sourcing a flexible heater manufacturer, two options dominate the market: the Polyimide Heater and the Silicone Rubber Heater. Both do the same basic job—convert electrical energy into heat—but they shine in very different environments.

What Is a Polyimide Heater?

A Polyimide Heater, also known as a Kapton Polyimide Heater, is an ultra-thin, flexible heating element made by laminating etched-foil resistance circuits between layers of polyimide film. Due to its flexibility and used the same raw materials of FPC, it also called flexible circuits by some users. Polyimide is a high-temperature, chemically stable, and electrically strong polymer widely used in aerospace, medical devices, and precision electronics.

Its etched-foil design produces uniform heat distribution, exceptional thinness and fast thermal response. These heaters are ideal for environments where weight, space, and precision heating are critical.

Typical Specs

• Thickness: ~0.13-0.4 mm
• Temperature range: –200°C to +200°C
• Applications: aerospace sensors, battery warming, optical devices, medical instruments, 3C electronics

Key Advantages of Kapton Polyimide Heater

• Ultra-thin & lightweight
• Excellent temperature precision
• High dielectric strength
• Chemical and moisture resistance
• Minimal outgassing
• Custom shape compatibility
• Fast thermal response

Limitations of Polyimide Heater

1. Not recommended for long-term high-power heating
2. Less mechanically robust compared to silicone rubber
3. Cannot be used where insulation thickness must be higher
4. Higher cost than silicone rubber heaters

What Is a Silicone Rubber Heater?

A Silicone Rubber Heater (also referred to as silicone rubber heating film, silicone heating pad, or silicone heating element) is a flexible heater constructed by laminating resistance wires or etched-foil circuits within layers of silicone rubber. Silicone is durable, elastic, and capable of operating under harsh industrial conditions.

Silicone heaters are widely used for freeze protection, battery warming, 3D printers, medical devices, tank heating, and industrial machinery.

Typical Specs

• Thickness: ~1–3 mm
• Temperature range: –60°C to +230°C
• Applications: freeze protection, medical devices, 3D printers, industrial equipment, food heating, chemical drums

Key Advantages of Silicone Heating Film

• High mechanical strength
• Higher watt density capability
• Moisture & chemical resistance
• Custom shapes, cutouts, and mounting options
• Stable performance at high temperatures
• Good Moisture and Weather Resistance
• Customizable With Embedded Sensors
• Cost-Effective for Larger Sizes

Limitations of Silicone Heating Film

1. Standard thickness 1.0–1.5 mm; not suitable for ultra-thin assemblies.
2. Higher thermal mass results in slower heating compared to polyimide.
3. Less suitable for cleanroom or vacuum applications
4. Higher outgassing than polyimide.
5. Works well for general heating but not for tight thermal tolerance.

Polyimide Heater vs Silicone Rubber Heater Comparison Table

Feature	Polyimide Heater (Kapton)	Silicone Rubber Heater
Thickness	Extremely thin (~0.13–0.4 mm)	Thicker (~1.0–3 mm)
Flexibility	High	Medium–High
Temperature Uniformity	Excellent	Very good
Max Operating Temp	~200°C	~280°C
Durability	Moderate	Very high
Response Time	Faster	Slower
Moisture Resistance	Moderate	Excellent
Chemical Resistance	Excellent	Good
Cost	Higher	Lower
Outgassing	Very low	Medium
Watt Density	Low–medium	Medium–high
Typical Use	Precision electronics, sensors, aerospace, optics	Industrial heating, medical pads, freeze protection

Which Heater Heats Faster?

A polyimide heater heats faster because its thin structure reduces thermal mass and its etched foil circuit transfers heat with minimal delay.

Silicone rubber heaters still provide reliable heating, but the thicker insulation makes the warm-up more gradual.

Are Custom Shapes Available for Both Polyimide and Silicone Heaters?

Yes. Both heater types can be manufactured in custom shapes, including:

• 3D Contours

• Holes & cutouts
• Irregular shapes
• Integrated thermostat or RTD/thermocouple sensors
• Different lead wire exit points
• Circuit pattern
• Connector style
• Voltage and watt density
• Mounting adhesive or hardware

A Flexible Heater Manufacturer such as Danyu Electronics offers complete customization from prototype to mass production.

How to Choose the Suitable Flexible Heater for Your Project?

Use this quick engineering guide:

Choose a Polyimide Heater if:

• You need extreme thinness
• Fast thermal response is critical
• The heater will be used in cleanroom, medical, aerospace, or sensors
• The environment requires chemical resistance
• You need a heater for low or medium watt density
• Precision temperature control is important

Choose a Silicone Rubber Heater if:

• You need durability and long life
• The environment is humid, outdoor, or harsh
• You require high power heating
• There is mechanical movement or vibration
• You need a large-area heater

For most commercial and industrial heating tasks, silicone rubber heaters remain the default choice. For precision and lightweight electronics, polyimide heaters dominate. If you’re unsure, Danyu Electronics can analyze your application and recommend the best heater material, wattage, and design.

Why Choose Danyu Electronics as Your Heating Solution Provider?

If you are searching for a reliable flexible heater manufacturer who can provide high quality heaters, Danyu electronics is your preferred choice. We offer full turnkey flexible heating services from design, evaluation, manufacturing and after-sales service. Our product ranges from Kapton polyimide heater, silicone rubber heater, optically clear heater (transparent heater) and thick film heater. If choose us, you can enjoy:

• Etched-foil heater design
• Custom silicone heating film and silicone heating element assembly
• Integrated sensors for precise monitoring
• Stable lamination and vulcanization processes
• Fast prototyping and dependable mass production
• Engineering guidance for material choice, adhesive selection, and environment analysis

Our engineers help with:

• Watt density calculation
• Heat distribution design
• Thermistor/RTD integration
• Adhesive selection
• Thermal simulation (upon request)

So, if you unsure which watt density or voltage is suitable for your project, our engineer can provide the best solution for you. Our team works closely with customers to create heaters that perform reliably, whether the project is a compact sensor module or a large industrial heating pad. Contact us if you are interested in flexible heater manufacturing.

FAQs

1. Can Polyimide heaters include temperature sensors?

Yes. RTDs, NTCs, or thermocouples can be integrated within the polyimide layer stack.

2. Is silicone rubber heater waterproof?

Silicone rubber itself is waterproof and can be sealed for IP-rated applications.

3. Can both heater types be adhesive-backed?

Yes. PSA such as 3M 467MP (for polyimide) or silicone-based PSA (for silicone heaters) can be added.

4. Which heater is better for battery packs?

Polyimide for compact, lightweight packs.

Silicone for rugged outdoor packs or EV applications.

5. Why does polyimide offer better precision?

Etched-foil circuits produce uniform resistance patterns, enabling precise temperature control.

6. Is silicone heater safe for long-term high-temperature use?

Yes, silicone maintains stability up to ~260°C and is widely used for industrial heating.

tags：Flexible heater manufacturer · kapton polyimide heater · silicone heating pad