The mechanism of an aerosol dispenser relies on pressurized gas to expel a product, typically a liquid mixture, as a fine spray.
Here's a breakdown of the process:
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Pressurized Propellant: An aerosol can contains a propellant, which is a substance that exists as a gas under pressure. Some of this propellant remains in its gaseous state above the liquid product.
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Pressure Application: The gaseous propellant exerts pressure on the liquid mixture (the product itself and liquefied propellant) within the can.
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Dip Tube Action: This pressure forces the liquid mixture up a dip tube, which is a small tube extending from the bottom of the can to the valve.
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Valve Activation: When the user presses the actuator, the valve opens.
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Ejection and Atomization: The pressurized liquid mixture is forced through a small nozzle in the valve. As it exits into the environment, the liquefied propellant rapidly vaporizes. This rapid vaporization causes the remaining product to break into very fine droplets, creating the aerosol spray.
In simpler terms, think of it like this: The propellant pushes the liquid up a straw, and when you press the nozzle, the sudden release of pressure turns the liquid into a mist. The propellant does two main things:
- Applies pressure to force liquid out
- Aids in atomizing (breaking into tiny droplets) the liquid stream as it exits.
