WEBVTT

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This is the NASA eClips Best Practices
guide for the Polyamide Foam Educator Guide.

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What do a rocket, an airplane,
and a house all have in common?

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They all contain materials called insulators.
An insulator is a material or substance that does

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not conduct heat, sound, or electricity easily.
They can be used to help contain energy within a

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system, like insulation in housing, or protect
the outside of a system, like rubber on wires.

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Insulators can also be used to help protect
people. Earplugs are an example of insulators

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that protect people from very loud sounds,
as loud sounds can be harmful to your ears.

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A sound's volume is determined by its amplitude
which is a measure of the height of a sound wave.

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You can visualize a sound wave by
looking at a guitar string being plucked.

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Where the bigger the vibration,
the louder the sound will be.

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A deciel is a unit used to measure sound intensity

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or the amount of energy being
transferred by a sound wave.

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Very quiet sounds, like a leaf falling, will have
a low decel count. And very loud sounds, like a

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rocket launching, will have a high decel count.
Rocket launchers release a lot of energy both in

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sound and in heat. Because of this researchers
NASA developed something called polyamide foam.

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Polyamide foam is a low density foam, which
means it has a lot of pockets of air within it.

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This makes it a very good sound insulator.
Sounds enter the foam with a high amplitude.

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They then get trapped in those little pockets
of air and the foam will absorb some of their

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energy. Then when the sound exits the
foam it will have a lower amplitude.

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Today, polyamide foam is most
commonly used in Navy ships,

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but as the technology develops
and it becomes cheaper to produce,

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it will be seen more frequently in
rockets, airplanes, and yes, even houses.

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You can learn more about insulators and

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polyamide foam in the NASA eClips
Polyamide Foam Educator Guide.