Structure and range of use of foil heaters:

Foil heaters are very flat heaters, made of heating wires or etched heating foils. The total resistance (which is equal to the heat output) depends on the specific resistance of the wire, the cross section and the total length (equivalent for the foils: The specific resistance of the foil, thickness, length and width of the track). Following the formula “U =R * I” the heating capability is a product of the adjusted voltage.

According to a various density of wires / tracks regions with different capabilities can be created. Constant temperature of 150 °C is possible. To simplify the installation the heating foils can carry an adhesive component on one or on both sides. Thickness of this adhesive component is from 50 µm – 150 µm.

Area of application of Vaas heating-foils:

- Semiconductor production
- Optoelectronics
- Aeronautics and aerospace
- Medical technology
- Safety engineering and machine-construction
- Telecommunication

Advantages of foil heaters against conventional heating:

- Very good and steady heat allocation across the entire heating area
- As a consequence of this: Safeness and reliable overheat-protection (no accidentally hot spots)
- Short heating time, short reheating time
- Long life cycle, high durability
- Weight-saving and space-saving (due to the little thickness and the flexibility)
- Precise control due to the small dead weight and thereby the very small
  transition resistance from the heater to the heat receiver
- Possibility of regions with different temperatures that can be served with one product
- As a result of the flexibility and the thickness of the material: Possibility to realize every imaginable layout
  and dimension and due to this a nearly unlimited range of use
- Realization of 3-D layout possible
 

Floor panel heater
Range of use: Aviation
250 x 400 mm

Door lock heater
Range of use: Aviation
120 x 50 mm

Valve heater
Range of use: Aviation
120 x 20 mm

Additional construction units:

Of course there is the possibility to link flexible connections or other functional parts with the heating foil. Depending upon the range of use the application of temperature sensors is recommended. Other functional parts can be included.

Calculation of the capacity of heating foils:

The calculation follows the basic principles of the electrical engineering:

P=U * I          and       U=R * I

2 details are necessary for calculation, e.g.:
P= 400W         U= 110V 
 

The basic parameter for the calculation of the layout is the resistance.

Example:

I = P / U –› 400 VA / 110 V = 3,6 A
This leads to a resistance of:
R = U / I –› 110 V / 3,6 A = 30,55 Ohm

The calculation of the layout depends on the specific resistance of the foil, their cross section and the heating area. 
The length of the heating track with 1 mm width is a result of the resistance of the thickness of the wire and the calculated resistance of the heating foil e.g.:

Heating foil 50 µm        

Heating foil 50 µm, with a track width of 1mm requests a track length of 1,06 m. in thus in our example in the case of heating foil 50 µ thickness a table of 1.06m. As a consequence of this the final step is to determine the optimal surface allocation of the heating foil.