Aerosol Sprays
By: Darius Wilson and Metztonalli Garcia
Aerosol Spray
History
Gas Law: Boyle's Law
Boyle's law and how it relates to aerosol cans
While there are a couple different types of aerosol cans, each one more elaborate than the other, they both operate off of the same basic principle: Boyle's law. For example a spray can of paint.
before you use a can of paint you are supposed to shake the can. There are 2 substances inside the can, one being your product, which in this case is paint and the other being a gas that can be pressurized so much, that it retains a liquid state even when it is heated past its boiling point. This liquefied gas will be a substance that has a boiling point far below room temperature. The can is sealed, preventing this gas from boiling and turning into a gaseous state. That is, until you push down the nozzle. The moment the nozzle goes down, and the seal is released, there is now an escape route. The propellant instantly boils and expands into a gas and pushes down on the product trying to escape the high pressure, and expand it's volume the atmosphere where there is less pressure. This forces the product to shoot out from the nozzle up the dip tube, and you have your paint.