This is the NASA eClips Best Practices guide for the Polyamide Foam Educator Guide.
What do a rocket, an airplane, and a house all have in common?
They all contain materials called insulators. An insulator is a material or substance that does
not conduct heat, sound, or electricity easily. They can be used to help contain energy within a
system, like insulation in housing, or protect the outside of a system, like rubber on wires.
Insulators can also be used to help protect people. Earplugs are an example of insulators
that protect people from very loud sounds, as loud sounds can be harmful to your ears.
A sound's volume is determined by its amplitude which is a measure of the height of a sound wave.
You can visualize a sound wave by looking at a guitar string being plucked.
Where the bigger the vibration, the louder the sound will be.
A deciel is a unit used to measure sound intensity
or the amount of energy being transferred by a sound wave.
Very quiet sounds, like a leaf falling, will have a low decel count. And very loud sounds, like a
rocket launching, will have a high decel count. Rocket launchers release a lot of energy both in
sound and in heat. Because of this researchers NASA developed something called polyamide foam.
Polyamide foam is a low density foam, which means it has a lot of pockets of air within it.
This makes it a very good sound insulator. Sounds enter the foam with a high amplitude.
They then get trapped in those little pockets of air and the foam will absorb some of their
energy. Then when the sound exits the foam it will have a lower amplitude.
Today, polyamide foam is most commonly used in Navy ships,
but as the technology develops and it becomes cheaper to produce,
it will be seen more frequently in rockets, airplanes, and yes, even houses.
You can learn more about insulators and
polyamide foam in the NASA eClips Polyamide Foam Educator Guide.