Earth-wise aerosols

A key tool in the convenient provision of all manner of products, from hair care to condiments, dispensing technology is a crucial part of the packaging process. The concept is a mystery to most consumers, but is nonetheless sought out in the packaging of products they consume - most notably in the form of aerosols.

If a brand-owner were to randomly select a household and wager on a particular type of packaging being found there, a favourite pick would probably be aerosols.

Foods, pharmaceuticals, medical devices, personal care, cosmetics, air treatments, cleaners, polishers, lubricants, paints, insect repellants and gardening: these are among the many categories that include products marketed as aerosols. The list can even be said to include toys, with examples like the aerosol used to dispense Silly String. With a broad range of applications, aerosols are used throughout households and away from the home.

Clean convenience

To perceive something as being a 'push-button' or 'spray-on' product is to perceive it as easy to use and convenient - qualities that are so inherent to aerosols, they are rarely stated as elements of promotion to consumers. Safety is another benefit: because aerosols are hermetically sealed, breakages, spills and leaks are of far lower concern. Hermetic sealing is also an effective safeguard against product tampering. Aerosols also boast the avoidance of unwanted contact with body parts, particularly hands: no external mixing ensures clean-hand dispensing.

As consumers can control how much is dispensed with an aerosol, usage customisation is achieved and dispensing waste is reduced - or altogether eliminated. The use of pressure to dispense also ensures there is nothing left in the bottle or tube at the end of the product's life, reducing waste further, in contrast to the inaccessible remains familiar to pump dispensers.
Sanitation is another key benefit of aerosols. Members of a household can share products such as aerosol deodorants without the same concern for hygiene associated with cream, stick and roll-on varieties.

The machine behind the curtain

Despite the widespread popularity - and resultant familiarity - of aerosols, there's something of a 'black box' aspect about them: their outputs are directly observable, but their inner workings are not. Unlike other types of packaging, one does not open an aerosol to view the contents, and the metal cans are not see-through. The product's mechanics are something of a puzzle to most consumers.
It's not just consumers, however, to whom aerosols are a mystery. Many packaging professionals could perhaps benefit from a more in-depth understanding of the dispensing system. Even if someone's business is not currently associated with aerosols, future opportunities might change that - and besides, why not ensure you're prepared for a layperson's basic questions, whenever and wherever posed?

Aerosols consist of multiple components, external and internal. The external components are the can itself and a covering cap (removable or integrated), and the actuator, which, upon being pressed, dispenses the contents of the can through a valve opening. Another external component, although not observable on all types of aerosols, is a valve cup that seals the top of the can.

Propellant and product reside inside the can, as distinct phases (layers) or intermixed. Aerosols operate under the laws of vaporisation, which govern the relationship between pressure and states of matter. Propellant gas is filled into the can under enough pressure to convert it into a liquid, and when the aerosol is activated, internal pressure forces the propellant and product up through the dip tube and through the opening in the actuator. When the liquid propellant and product are dispensed into the ambient pressure, the liquid converts back into a gas. As it is dispensed, some of the liquid propellant that remains in the can vaporises into a gas, thereby maintaining internal pressure. This cycle repeats until the can is empty.

Protect the Earth

Despite the convenience presented by the aerosol format, the fact that it means propellant gas is being dispensed into the air invites concerns about its environmental effects. Suppliers and users alike in the aerosol industry grappled with such issues even before the era of sustainability descended.

Progress is being made, though: companies like Unilever have successfully developed deodorants that cut its carbon footprint by 25% or more. By making the cans themselves smaller, for instance, it can save material use, and the aerosols need proportionally less propellant for spraying. Less material per pack also means more packs per pallet, so transportation uses less fuel - which translates into enormous cost savings in transportation. There has also been a shift in the industry towards using recyclable materials in the cans themselves, extending material life to benefit the environment.

There have also been significant improvements made to the propellants used in aerosols. Use of chlorofluorocarbon as a propellant, which contributed to ozone depletion, was phased out by 2010 under the Montreal Protocol, and aerosols today make use of compressed gas and mixtures of hydrocarbons. The technology is far from perfect, but research is ongoing to optimise use of compressed air and inert gas in order to further reduce environmental impact.

As the technology to make aerosols grows more sustainable, the format's functionality and inherent ease of use remains fundamental to consumers' enjoyment of the product, and this is what will ensure its continued success.

Dispensing innovations identified by Canadean Consumer's Pack-Track

Mineral Wear (Physicians Formula, US)

This mineral foundation gives the consumer the option to apply the foundation with an integral sponge applicator or, for targeted application, unscrew the applicator so the foundation can be applied with fingertips. The sponge material is said to contain an antimicrobial agent to keep the applicator 'pure and safe'.
The format is well suited for on-the-go use: the built-in applicator means the foundation can be applied straight from the pack, without hand contact, and the overcap carries a mirror. The tottle shape also makes it easy to hold, and the application process is not dissimilar to applying foundation with a brush.

Must-Have cream (JYB Cosmetics, UK and Belgium)

JYB's Must-Have cream is packaged in a new variation of the airless pump format, with an added flexible inner tube. Unlike the regular airless pump, where the base inside moves against the outer tube and pack integrity relies on the tightness of this contact, this variation means the product is fully contained inside the flexible tube or pouch, which is sealed to the base and closure for extra protection against oxidation and contamination. The inner bag collapses as the product is used and can be seen through the outer tube, enabling the consumer to see how much product remains and when the pack is fully empty.
The addition of the elastomer valve to the dispensing nozzle prevents air intake, offering further protection to the product and prolonging its usable period after initial opening. It also helps to keep the closure clean.

Dual Stylers range by Tecni.ART (L'Oréal, UK)

Dual-tube formats for two-part hair conditioner are not new, but The Dual Stylers range is the first instance we have seen of a tube-within-a-tube format. The pack format enables consumers to disperse the correct balance of two complementary hairstyling products.
The packaging is not perfect, however: the right amount of pressure must be applied to the tube to allow the correct balance of product to be dispensed. Too little pressure results in too little of the cream component being dispensed. There is also a tendency for the gel to seep out of the neck of the tube as the pack is handled or held upright before squeeze dispensing.

Sheer Blonde Go Blonder (John Frieda, UK)

An in-shower hair lightening treatment, Sheer Blonde Go Blonder comes in a single-use dual-tube format. The two product components are kept separate in their respective tubes prior to use, but are dispensed simultaneously and mixed by the time they reach the consumer's hand, resulting in a cleaner and simpler user experience. The advanced packaging imparts a sense of scientific effectiveness.

These kinds of added-value features on hair care packs, particularly those used for colourants, improve convenience and cleanliness for the consumer. Dual packs that combine two products on dispersal simplify the preparation process, making usage quicker and more efficient, while applicators keep the user's hands clean. Adjustable dosing or dispensing allows the consumer greater control over the final result and provides an experience that is customised to suit the individual.