Aerosol spray dispenser

In 1939, American Julian S. Kahn received a patent for a disposable spray can,[5][6] but the product remained largely undeveloped.

It was a hand-sized steel can charged with a liquefied gas under 75 pounds of pressure and a product to be expelled as a mist or a foam.

[9] A public-service patent was issued on the invention and assigned to the Secretary of Agriculture for the free use of the people of the United States.

[10] Pressurized by liquefied gas, which gave it propellant qualities, the small, portable can enabled soldiers to defend themselves against malaria-carrying mosquitoes by spraying inside tents and airplanes in the Pacific during World War II.

Frank Sherwood Rowland and Mario J. Molina proposed that chlorofluorocarbons, used as propellants in aerosol sprays, contributed to the depletion of Earth's ozone layer.

[13] In response to this theory, the U.S. Congress passed amendments to the Clean Air Act in 1977 authorizing the Environmental Protection Agency to regulate the presence of CFCs in the atmosphere.

[15] In 1985, Joe Farman, Brian G. Gardiner, and Jon Shanklin published the first scientific paper detailing the hole in the ozone layer.

Nitrous oxide and carbon dioxide are also used as propellants to deliver foodstuffs (for example, whipped cream and cooking spray).

Liquid aerosol propellant filling machines require additional precautions, such as being mounted externally to the production warehouse in a gas house.

The can is most commonly lacquered tinplate (steel with a layer of tin) and may be made of two or three pieces of metal crimped together.

The valve is crimped to the inside rim of the can, and the design of this component is important in determining the spray rate.

The main benefit of this system is that it eliminates gas permeation and assures separation of the product from the propellant, maintaining the purity and integrity of the formulation throughout its consumer lifespan.

Another type of dispensing system is the bag-in-can (or BOV, bag-on-valve technology) system where the product is separated from the pressurizing agent with a hermetically sealed, multi-layered laminated pouch, which maintains complete formulation integrity so only pure product is dispensed.

[23] Among its many benefits, the bag-in-can system extends a product's shelf life, is suitable for all-attitude, (360-degree) dispensing, quiet and non-chilling discharge.

A 2K aerosol can increase solid contents and deliver high-performance polymer products, such as curable paints, foams, and adhesives.