is the best single example of the heat transfer
difference between a
conventional and thermally conductive plastic.
infrared image shows color differences as a indication
of temperature gradients in the part.
part is a 3 x 3 x 1/8 inch (75 x 75 x
3 mm) injection molded plaque with a small 5 watt
heater attached to the back side.
the left, the conventional plastic can not spread or
dissipate the energy and therefore, a “hot spot”
develops in the center of the part.
right, there are two important effects.
First, the input energy is spread throughout the
part resulting in a more isothermal temperature
distribution (noted by the similarity in color).
Secondly, since a much larger surface area has
been heated, the energy is more efficiently transferred
to the environment and the temperature of the device and
“hot spot” is significantly reduced.
this were a real application the heater (or any heat
generating device…a microprocessor, a resistor, a light
bulb) would run significantly cooler.
Decreasing temperature almost always increases
device efficiency, lifetime or power output.
Specific plastics are often selected based solely on its
ability to withstand a given hot spot temperature
created in the application.
Reducing rather than surviving this temperature
is one of the fundamental concepts of a thermally
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