The fragrance experience

18th of September 2019
The fragrance experience
The fragrance experience

There are many different and ingenious ways of perfuming a room and today’s air fresheners come in the form of solids, mists, sprays and gels. Paul Wonnacott, managing director at Vectair Systems, discusses the pros and cons of each format, how they work and what the future holds for fragrance systems.

It’s an exciting time for the aircare industry. Experts have estimated that the global air freshener market is set to increase from $10 billion (€9 billion) in 2016 to $12 billion dollars (€10.83 billion) by 2023. As manufacturers, we are constantly listening to the market and creating newer and better solutions. We know what our loyal and traditional cleaning sector wants but we also know that our audience is growing.

Scent is appealing to more and more markets including hoteliers and retailers. High-end hotels traditionally used candles and reed diffusers in their lobbies but they are realising the powerful effects of being able to control their fragrance output. They want more powerful fragrance that lasts longer. They want cleaner solutions that have less of an impact on the environment. This provides a huge opportunity for us to innovate and experiment with new ways of scenting a space and reaching out to these markets. That can only mean better outcomes for the cleaning sector too.

It used to be all about disguising bad odours, and replacing them with a fresh scent. Now we are tasked with creating an experience with fragrance. Citrus has always been a staple scent for the public washroom – and in many ways it still is – but more refined scents are emerging and we are starting to see ‘trends’ like they have in the consumer perfume market.

We are putting much more thought into the effects air fresheners have on global warming, and telling stories about where our products come from and what they are made of. Dispenser design is also becoming more sophisticated, as now we are placing a greater emphasis on aircare products being part of the wider landscape.

It has been a long time since aerosols ruled the aircare market. On offer now are solid fragrance cartridges, gels, nebulisers, atomisers, diffusers… each solution providing different advantages and disadvantages. We can categorise air fresheners into two main groups – powered and passive.

‘Powered’ means that an air freshener refill sits in a dispenser and needs either batteries or mains power to work. ‘Passive’ means that the air freshener works without a power source and instead needs just air to function. We can also categorise air fresheners by those that are continuous and those that are instant action.

Lasts longer

Powered air fresheners include metered aerosol pump sprays, nebulisers, atomisers and diffusers. Each have pros and cons, depending on what the consumer is looking for.

Metered aerosol pump sprays are what we traditionally see in the public washroom. Aerosols contain two different substances - the liquid fragrance and a pressurised gas called a propellant that helps to push the liquid product out into the air in the form of a spray. There is a valve at the top of the can which has a spring to stop it staying permanently open. When you force the button down against the pressure of the spring, the valve opens and reduces the pressure at the top of the can, allowing the contents to escape. Release the button and the spring closes the valve again.

One benefit of an aerosol air freshener is that it usually comes in a fully programmable dispenser, allowing you to programme it depending on location. Some dispensers offer an extra fragrance boost during busy periods. Metered valves mean each spray delivers the exact same dose of fragrance each time. Dispensers are battery operated and battery life is good. Users can fairly accurately predict the end life of a cartridge, and programmable dispensers will tell you when a cartridge needs to be replaced.

The dispenser can be wall mounted which saves on countertop space and even though it is up on the wall, it should be fairly easy for whoever is servicing the dispenser to change the cartridge. Aerosol dispensers are usually lockable so that they can’t be easily vandalised.

Programmable dispensers

The main negative is that there is a lack of torque due to being powered by batteries, resulting in a heavy mist or poor atomisation. Fragrance falls very quickly and can create ‘pooling’ beneath the dispenser (sometimes on countertops or fittings). Fragrance coverage is reasonable, but has a short ‘hang’ time so the impact of the air freshener is challenged. Aerosol sprays are prone to dripping from the nozzle especially when batteries are low.

They can also be moderately noisy on actuation (hands up who has been startled by an aerosol air freshener spraying in a quiet washroom). The use of propellants in aerosol sprays isn’t dangerous but it’s also not the most environmentally friendly, so many consumers are choosing to go ‘propellant free’ by using other forms of air freshening systems.

The technology behind nebuliser air fresheners, including vibrating mesh technology, originated from the medical profession. In medicine a nebuliser is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. In the air freshener market, nebulisers have the capability to fill large spaces with safe formulations of fragrance.

They convert liquid fragrance oil (without all the chemical ingredients) into a fine vapour which is pushed out into the atmosphere via a pump. In vibrating mesh technology, a mesh or membrane with 2,000 laser cut holes vibrates at the bottom of a reservoir, and thereby pressures out a mist of very fine droplets through the holes.

High performance

The positive aspect of nebulisers is that they are very effective in terms of performance. Fragrance particles are much lighter and so linger in the air much longer. Units can be wall mounted but they can also be placed on countertops, which from a design sense, makes them more versatile. Refills are easy to change and easy to install.

They are however not silent – in fact they can be quite noisy due to a motorised pump. They are most likely to need power from an outlet which means limitations on where they can be placed. Manufacturers cannot guarantee the exact amount of fragrance used per delivery, and dispensers usually require a vertical ‘jet’ stream so need to be kept upright.

Ultrasonic diffusers are similar but they use water as a transference method – the fragrance oil sits on top of the water and ultrasonic vibrations are created to agitate the water causing the separation of the oil molecules, which releases fragrance particles into the air with a fine mist.

Essential oil diffusers can also act as humidifiers, but the amount of moisture added to the air is minimal. These types of air fresheners are good at scenting small spaces, but they are less effective in terms of fragrance strength and are limited in where they can be placed due to their design criteria.

The very first atomiser nozzle was invented by a doctor in Ohio, USA in the late 19th century, who produced a fine spray of liquid based on the venturi effect. The venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. Think of a straw in a drink – when you put your finger over the top of the straw and lift it out of the cup, the
liquid is held in the straw until you remove your finger. His device was used for spraying medicine on the back of his patients’ throats.

The air freshener atomiser is a glass, metal or plastic container which operates in a similar fashion to an aerosol dispenser except that the actuator is a pump, which when pressed a few times creates the pressure to aspirate the fragrance from the container through a tube into the actuator and spray nozzle. The big difference is that the bottle contains just the liquid fragrance – there is no propellant at all.

When you pump the trigger mechanism, you lower the air pressure in the tube running down into the bottle. Because there’s air inside the bottle, at the top, the liquid is forced up the tube. The pump mechanism forces some of this liquid out through the tube into a much smaller nozzle, so it turns into a high-speed aerosol of tiny droplets.

Solid air fresheners are a good example of ‘passive’ dispensers that don’t need batteries or mains power to work. Passive solutions include wicks (candle wicks for example), reed diffusers and gels. Gels are simply fragrance oil in a solid form – the evaporation process gradually releases fragrance oil into the air.

Candles set the scene and can provide a wonderful atmosphere, but there is always the danger of fire, as well as concern over the nasty chemicals that candles can emit. Reed diffusers look appealing but are open to being vandalised or stolen, and can also be dangerous to young children who might tamper with them.

Consistent, sophisticated

Solid air freshener systems provide continuous fragrance to small to medium sized spaces, in a safe and discreet dispenser. They can be made up of an inner core and an outer material, which can contain different fragrances, allowing for a multi-phasing effect. The ceramic is infused with high quality fragrance which evaporates at a different speed to the core.

Consumers tend to appreciate the materials used in solid air fresheners, with ingredients like seaweed and materials like EVA (ethylene-vinyl acetate). One big advantage of a solid air freshener is it is simple to use – there is little human interaction required and the system can be left to run by itself. It is ideal for use in smaller or harder-to-reach areas like lifts and corridors.

The downside of passive air fresheners is the inability to programme them. The popularity of fully programmable technology is on the rise, with customers appreciating the ability to fully control their dispenser outputs. If a fragrance is too strong, they can turn it down, or vice versa. Consistency is also key—people want fragrance that lasts, mainly due to the fact that fragrances are becoming more pleasing.

For an aircare dispenser to be truly consistent, it needs efficient fragrance dispersal, dispensing a fine mist with smaller particles that stay in the air for longer. Ultimately, sophisticated venues need sophisticated, state-of-the-art aircare systems – and we continue to innovate to fill that need.


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