By doing away with flammable propellants such as VOCs, the technology is also set to transform supermarket shelves – replacing uniform rows of cylindrical aluminium aerosol cans with low-cost polyethylene terephthalate (PET) bottles in a range of shapes and sizes. And the smaller air bubbles in the foam give a smoother texture – for things like shaving foam or whipped cream – than conventional techniques. The technology could also bring molecular gastronomy at the touch of a button into the home – opening up the possibility of picking up restaurant-style foams in a bottle with the weekly food shop.
Traditionally, a VOC – typically propane and/or butane – is liquefied inside an aerosol can together with a foaming agent and the solution to be dispensed. The VOCs are liquefied at the pressure within the can – typically around four bar. When the valve is opened, the mixture is expelled through the nozzle and the VOC flashes off as a vapour. The expanding gas puffs the foaming agent up to a froth.
The new foaming technology devised by Cambridge Consultants does not require dissolved or liquefied gases such as VOCs or even carbon dioxide or nitrous oxide – the foam is formed simply with compressed air or nitrogen. The bubbles produced are a fraction of the size of a grain of sand – with a diameter of less than 40 microns – giving a very creamy texture. Yet the cost is lower than traditional products – and they can still be manufactured on a standard aerosol production line.
VOCs – used for non-food aerosol applications ranging from hair mousse to sunscreen – contribute to the creation of ground-level ozone, which has been linked to respiratory problems. In California, the Environmental Protection Agency has already placed limits on the amount of VOCs that can be included in aerosol products such as deodorants and antiperspirants. Europe has limited the levels of VOCs in paint products – with similar legislation imminent for deodorants and antiperspirants.
"Our technology provides an environmentally-friendly alternative that will enable companies to get ahead of the impending legislation and gain first-mover advantage," said Mark Nicmanis, senior technologist at Cambridge Consultants. "It doesn't require VOCs or flammable propellants – which allows the use of low-cost, attractively-shaped PET bottles without presenting a fire hazard for warehouses. PET bottles typically cost half as much to produce as aluminium cans. And on top of the environmental benefits of doing away with VOCs, PET bottles can be recycled and have half the environmental impact of aluminium cans.
"This latest example of our dispensing solutions expertise, for which a patent is pending, also benefits the consumer – the smaller and more consistent air bubbles give a creamier, more luxurious texture and a better sensory experience. And it gives us the ability to foam things that are traditionally difficult to foam – like foundation cream or insulating materials – giving FMCG companies the opportunity to differentiate in crowded markets. Dermal delivery – the delivery of active ingredients through the skin – is another area we are exploring. Foams have great potential for this as they don't run and they make it easy to distribute small amounts of high-value actives very evenly."
The foaming technology could also be incorporated into an appliance – or into a disposable pod for use in conjunction with an appliance – to create milkshakes, ice cream or milk froth for coffee machines. It is equally applicable to dispensing systems for things such as soap or shaving foam that use a motion sensor to automatically dispense a rich creamy foam when a hand is detected under the appliance nozzle.