Silicone Rubber Heaters

Silicone Rubber Heaters

Posted by Adelle Webber on

Silicon is the naturally occurring chemical element. 

Silicone is a synthetic rubber.

silicon rubber typesThe terms are often used interchangeably.  Raw Silicon is a hard and brittle crystalline solid. Silicone, synthetic rubber, is the material used in flexible heaters.

The unique properties of silicone rubber heaters make them ideal for applications that require a heater with the following characteristics.

  • Moisture & Chemical Resistance
  • Dimensional Stability
  • Flexibility
  • Lightweight
  • Thin
  • Rugged
  • High Uniform Watt Density
  • High-Temperature Resistance

Examples of Applications for Flexible Silicone Heaters

DBK USA offers a wide range of square, rectangular, and round heaters that can be ordered directly from their online store.  This offers quick delivery for testing or immediate need.  Custom sizes and coatings are available by contacting the company’s engineering department at 1-864-607-9047.

Applications for these off the self-heating elements span most industrial sectors where the characteristics of listed will be required or just extend the life of the heating elements.

  • Agriculture
  • Oil & Gas
  • Aviation
  • Space Exploration
  • Military
  • Medical Devices & Laboratories
  • Automotive
  • Transportation
  • Electronic Equipment Cabinets
  • Manufacturing Equipment
  • Mining

The list isn’t inclusive because someone is always discovering new uses for these unique heaters.  The off the shelf heaters range in size from 2 x 2 inches to 8 x 8 or 4 x 11 inches with power ratings up to 800 watts.  

How one of these heaters might be used

Anyone that lives in northern climates knows cold weather is tough on equipment stored outdoors.  This includes automobiles, tractors, trucks, snowplows, generators, pumps, snowmobiles, trains, and planes.  One of the weak points in cold weather is the batteries.  A flexible silicone heater placed under a battery can keep the battery from freezing up and ensure it can crank up the engine.  Heaters are available in 12V or 120V depending on the application.

Other cold-weather applications can include gas and oil pipeline valves,

windmill

windmills, and outdoor pumping equipment.  The flexible heaters are most suitable where attachment and wrapping around the surface to be heated is of value.  A heater sitting under a battery needs to be rugged and able to withstand wear from the weight of the battery itself.

Medical and lab equipment is another example where these small thin heating elements can be of value.  They can be wrapped around or attached to the surface of the container to be heated.  Their uniform heating and watt density can ensure that the laboratory device maintains a consistent temperature throughout the vessel being heated.

Manufacturing industrial equipment that requires heating such as dies or extruders can also be subject to moisture and cleaning solvents.  

Advantages of etched foil heaters

Etched foil has replaced resistive wire heaters for two primary reasons.  One is etched foil thinner than resistance wire and the other is more closely custom-designed heating patterns.

etched foil

The etched foil is similar to the aluminum foil you can purchase in a grocery store for wrapping food, except about half the thickness at .0025 inches.  The foil used in flexible heaters is made of specialized alloys for the desired electrical resistance.  Patterns of the foil are created through a chemical etching process, hence the name etched foil heater.

An example might be a medical device that needs heat applied specifically to critical areas of the device but not over the entire surface.  The necessary pattern can be designed into the chemically etched foil prior to vulcanization or lamination between silicone layers.

The consistent etching process from one heater to the next ensures more uniform heating across the surface of the device to be heated. It also allows lower current for watt density over wired heaters.  The flat surface area of the etched foil element versus circular area of wire provides better heating dissipation directed to the surface.

Where weight and size or thickness is a consideration these heating elements allow for higher watt densities and quick heat up capabilities.  Where a tight bend radius is required the etched foil outperforms wire.


Benefits of silicone rubber heaters

Silicone is resistant to water and chemicals and able to maintain these properties under high heat. DBK USA flexible heaters have a temperature operating range from -76 degrees F to 446 degrees F. 

The silicone rubber heaters are resistant to fungus, bacteria, acetone, alcohol, formic acid, hydrochloric acid, sulfuric acid, greases, and brake fluid.  These characteristics plus ruggedness extend the heater life compared to other heater coatings.

Silicone rubber heaters can be attached to surfaces via pressure-sensitive adhesive or built-in grommets.


Silicone Mixtures for Specific Applications

Silicone rubber is laminated or vulcanized over the etched circuits for barrier protection from the elements and physical damage.  The Silicone is a great electrical insulator and conducts heat well.  Here are some of the specialized silicone mixtures used that can be custom ordered for their intended applications.


H/SR Arlon® Silicone 1.5mm thick coating

Arlon

This silicone coating is used where high flexibility is required.  Used on non-adhesive products where holes, grommets, or other fastening devices are used.  Applications include drum and container heaters, composite repair, and plastic pipe flange heaters.

The DBK off the shelf flexible heaters have Arlon coating.



H/SR LSLT 12/12 = 1.5 mm thick coating

H/SR refers to high viscosity silicone rubber.  A low smoke, low toxicity specialized silicone.  This silicone rubber meets the stringent standards required for enclosed environments.  Applications include wind turbines, train heaters, submarines, underground trains, and tunnels.


H/SR-A 8/8 = 1.1 mm thick

Normally supplied with self-adhesive backing for static environments. Applications include anti-condensation, bain-marie, battery heaters, display cabinets, glass hotplates, heated food trolleys, and telecommunications.


H/SR 12/12 = 1.5 mm thick

Normally used for electrical insulating properties when high voltage 3 phase power is used.  Applications include plate press and satellite antenna heating.


Where insulation is needed to keep heat from escaping

8 mm silicone foam, closed-cell construction that can be adhered to the materials for exceptional thermal insulation.


Electrical Leads

Specialized electrical leads are used for each type of silicone mixture and application.  Here are some of the most common.  PTFE, silicone braided, unbraided, and silicone 2 core.

rubber silicon flexible heaters

Have questions about these specialized coverings and applications?

Call our thermal specialists at 1-864-607-9047 or visit our website to see all of our thermal management products.

 

Download Blog PDF for Silicone Rubber Heaters


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