Band heater: Mica and ceramic insulation

Band heaters are mainly used in injection molding machines and extruders in the plastics industry. Other applications include packaging machines and containers, and general heating of pipes.

 

The distinguishing feature of these elements is that the heat is evenly distributed over a large surface area.

 

The structure is composed of heating wires and insulated with mica plates or ceramic formers. Components are usually covered with metal to improve mechanical strength.

 

Mica and ceramic insulation

The mica insulating material has a thin structure (4mm) with a maximum wattage of 3.5 W/cm² and can work at temperatures up to 380°C. For process temperatures exceeding 280°, ceramic insulation is preferred.

 

Ceramic insulation heating band

The structure of the ceramic element is thick (12mm), but the watt density is 5.5 W/cm², and the working temperature is as high as 600°C. Generally, ceramic components are more durable than mica components, which offset the higher price and longer life expectancy.

 

Calculation of maximum rated power

Band heater (mica): P max (watts)

= Width (mm) x diameter (mm) x (3.14 x 0.035)

 

Band heater (ceramic): P max (watts)

= Width (mm) x diameter (mm) x (3.14 x 0.055)