What Is an Aerosol? How Spray Systems Work

What does aerosol mean?

Scientifically, an aerosol is a dispersion of small liquid droplets or solid particles in a gas. In the packaging industry, the word also describes a sealed system that uses pressure to dispense its contents. An aerosol is therefore not just a product formulation; it is also a way of packaging and applying a product.

An aerosol product does not have to emerge as a fine mist. Depending on the formulation and packaging system, it can be dispensed as a foam or in other forms. This distinction is also explained in the European Aerosol Federation’s introduction to aerosol dispensers.

What happens inside a spray can?

In a conventional aerosol system, the propellant creates the pressure needed to dispense the product. Pressing the actuator opens the valve. Depending on the system design, the product travels through a dip tube to the valve and actuator. Releasing the button closes the valve and stops the flow.

Propellants may be liquefied or compressed gases. These approaches do not behave identically. The Aerosol Association of Australia’s guide explains the relationship between pressure and dispensing. The appropriate system for a product needs to be determined through technical assessment.

What do the can, valve and actuator do?

• Can: The container that holds the product and pressurised system.
• Valve: The component that opens and closes the product outlet.
• Actuator: The button the user presses, which helps shape the discharged product.
• Cap: A component that, depending on its design, protects the actuator and completes the package.

Distinguishing these functions makes it easier to explain your requirements when requesting a quote. A fine mist and a targeted application are different expectations. Read our aerosol packaging selection guide to see how the components can be assessed together.

Is every spray an aerosol?

No. Spray is a broader term for applying a product by dispersing it. Hand-operated pump and trigger bottles are also called sprays. Asking for spray filling alone therefore does not always identify the packaging system you need.

When requesting a quote, specify whether you intend to use an aerosol can or a pump bottle. Spreysan’s contract aerosol and spray filling services concern aerosol products. Share your intended application and a packaging example to make the discussion more specific.

How can you describe an aerosol product idea?

You do not need to start with a chemical formula. Prepare a short brief explaining the intended use, how the user should apply the product and your preferred pack size. If you have a reference product, list the features you like and those you want to change separately.

Automotive care spray is a broad description. An automotive care product for targeted application in a particular pack size gives the discussion more direction. To prepare the commercial side of your project, read our guide to preparing for contract filling.