DENATRON Transparent film heaters

2018/02/26

We try an experiment using DENATRON and disposable hand warmers, necessities for winter in Japan.

Disposable hand warmers generate heat through chemical reactions between iron and oxygen.
DENATRON transparent film heaters, on the other hand, generate heat by passing electricity through an electrically conductive film applied on polyethylene terephthalate (PET).
This flexible film that is highly electrically conductive and which heats up uniformly.

First, we make a film heater.
DENATRON applied on PET film and dried up.
Electrodes are created with silver paste on both edges of the dried film.
When voltage is applied to the resulting film, its surface heated up uniformly.

①Film with electrodes after applying DENATRON coating.
②Highly transparent and flexible.
③Power on and heat generated.

Let’s use thermography to observe how the film heater and disposable body warmer generate heat.
We performed thermographic observation of the surface temperatures of the following:
●A disposable hand warmer
●A film heater to which a 10V voltage was applied
●A film heater to which a 20V voltage was applied

As the thermographic images show, the disposable hand warmer heated up gradually over time.
The heat it generated was also not uniform.
In contrast, the film heater (10V) heated up quickly and uniformly and then maintained its temperature.
When the voltage was doubled to 20V, it heated even further and maintained this higher temperature.

As these results show, when film heaters reach a certain temperature, they maintain that temperature, and the temperature can be adjusted by voltage.

This experiment shows that, although DENATRON film heaters require a power source, they offer superior heating speed and temperature control despite thin and transparent.
How about using it for heating and temperature control applications where transparency, light weight, and flexibility are required?