The Aerosol can has proven to be a popular product design and a great feat of engineering in past hundred years, to the extent that they are commonly used all around the world today. Aerosols have ranged from fire extinguishers to paint dispensers to even holding our common deodorant. The first aerosol was patented in 1929 in Norway. The container was made with thick brass walls to withstand the pressure in the can, which isn’t very convenient in modern times. These days aerosol cans don’t use such high pressures. This allows them to be much lighter and then mass produced. LYNX (also known as AXE) are a popular brand in the UK market that design deodorants in aerosol cans. They have been producing and designing all sorts of aerosol cans since 1983 to the present day. Each aerosol can being different, yet sharing the same qualities that all aerosol cans include in their product design. The deodorant that I personally looked at was the 2010 to present LYNX “Recover” aerosol can (as depicted above).

Okay, well firstly what are the components of an aerosol can? I have a diagram below to help. In a common aerosol can you would have the container which is normally made from welded tinplated steel, or extruded aluminium. Tinplate aerosol cans are predominantly made up of three components - a top containing the valve opening, a body and thirdly a bottom. Normally a low carbon mild steel sheet coated with tin and applied by electro deposition. Whereas aluminium cans are usually made from single piece of aluminium metal. Both metals are used because they are atheistically pleasing, lightweight and have good resistance to corrosion. Why is this important? Aerosol cans contain propellants which are violate hydrocarbons (pressurised gases and liquids) such as; n-butane, isobutane, propane and even alcohol. Therefore it is important for the material to successfully hold such things. The LYNX can I looked was made from aluminium. It is also significant to note that the pressure inside an aerosol can is greater than atmospheric pressure. It can range from 2 to 8 times the atmospheric pressure. This means that the can has to be exceptionally strong to withstand the difference in pressure between the inside and the outside.

The next components are the valve and the seal. A stainless steel spring pushes the head piece up, so the channel inlet is blocked by a tight seal. That connects to a dip tube (normally a clear polymer with good water resistance i.e. polypropylene, which is used for similar use e.g. laboratory equipment) that allows the propellant mixture to pass through when the pressure is added to the nozzle.

The LYNX aerosol has a different nozzle than the one depicted in the diagram, it has a tall (PET polyethylene terephthalate) polymer locking mechanism that can be twisted to lock and unlock the aerosol usage. This is a plastic which is the reasonable toughness for such an everyday use for this product. It is also similarly used for other caps and top such as for Coke bottles.

As discussed, the LYNX aerosol can is made from aluminium. This aluminium is extruded to form the initial shape of the container/can. Extrusion is a quick process and you can produce lots of the same shape for mass production. It is punched into a die which presses out the can shape without causing a steam on the can. The end result being a smooth surface finish. The lid/nozzle is made from PET which is preferably injection moulded, and the mould can be used over and over again keeping the cost down. The spring in the valve is coiled, a manufacturing process called coiling where the steel is wrapped around a mandrel. The dip tube is extruded polypropylene. Extrusion is used common for tubing and piping because you can create long lengths using just one mould making it cheaper in the long term.

The first step of construction is starting with the empty aluminium aerosol container. It is filled with the product containing all the active ingredients except for the propellant, usually in the form of a liquid. The volume of liquid is carefully controlled to ensure it conforms to weights and measures legislation.

The next part is fitting the valve with a dip tube. This is done so by a process called “crimping” which is a very careful operation using machinery in order that the seal does not leak. A small actuator is fitted to the valve before it is crimped onto the aerosol can to resolve this problem however. The propellant is then injected under pressure through the valve. It may be in the form of a liquefied gas or a compressed gas. If it a liquefied gas it will exist as a liquid and vapour in the aerosol can head space (the top of can). The volume of the liquid will increase as a result. However if a compressed gas is used it will usually sit in the head space above the liquid in the can, resulting in little or no increase to the liquid volume.

Due to the aerosol being under a pressured state with the additional propellant it is next tested for faults. The cans are immersed in a water bath at 50⁰C to check for any leaks of the product. Any that are found to are then rejected. Those that are good on the other hand are fitted with a cap or a nozzle.

Aerosol cans have a short product life cycle. The average life of a deodorant aerosol can would not be expected to exceed a few to one month. Deodorant is used by an average person once to three times a day and more. The aerosol can is considered to be a “throw away” item. However it can be recycled.

The UK deodorant market managed to grow from £501.93 million in 2009 to £516.65 million up to and including the first five months of 2010, which represented a modest growth of 2.9%. Volume sales were much more robust with a 7.3% growth over the same period – going from 332.58 million units in 2009 to 356.77 million this year. The female deodorant category accounted for the lion’s share of the market taking 68.5% of sales.

The brand LYNX play a key part in the success by offering something new each year. The type of fragrance variants have evolved over time. From 1983 until about 1989, the variant names were descriptions of the fragrances and included Musk, Spice, Amber, Marine, and Oriental. From 1990 until 1996, geographic names for fragrances were used, such as Africa, Alaska, Java, Nevada, and Inca. From 1996 to 2002, Axe took inspiration to develop the scents to launch variants, such as Dimension, Apollo, Dark Temptation, Gravity, and Phoenix. In 2009, the brand launched an 8-centimeter container called the Axe Bullet. In 2010 to present LYNX are still creating new scents for their deodorants and it doesn’t look like they will be stopping any time soon either.

When an aerosol can comes to the end of its product life cycle it considered to be a “throw away” item. However what becomes of it? Is it environmentally friendly? In terms of being environmentally friendly then yes it is. The parts that make up an aerosol can are recyclable. Ensure that the aerosol can is empty of the contents of before it’s recycled. This is important because aerosols contain all types of dangerous propellants. On January 12, 2008 a 12 year old boy in Derbyshire, England died in a hospital five days after collapsing at his home. The medical coroner ruled that he had suffered from cardiac arrhythmia and died from heart failure as a result of spraying large amounts of LYNX in a confined space. Common propellants such as liquefied petroleum gas (LPG) consist of high purity hydrocarbons derived from oil wells which are flammable. The more concerning ones like chloroflucarbons (CFCs) are no longer used in consumer aerosols in the western world due to the discovery that they were affecting changes in the ozone layer. Companies such as aerosolv are developing solutions for the waste disposal of aerosol cans. They have designed a unit that punchers and drains the aerosol can, filtering any harmful propellant through a metal drum and then crushing the can for it to be considered to be recyclable. Other recycling fertilities just ensure the consumer that the lid/nozzle/cap should be separated from the aluminium container. So that is it easier and more efficient to be crushed and melted down to form a new product.

After studying the LYNX aerosol can it has come to my attention that there are a number of advantages as well disadvantages to this particular product design. The efficiency of the aerosol can use is good. It is proven that function works for everyday use. The valve system inside an aerosol can is an efficient way of dispensing dangerous condensed gases and liquids under the average living temperatures. It is also a rather universal and easy to use product by anyone who wishes its use. In terms of the aerosol can aesthetically, again is it pretty faultless. LYNX have kept their costs low but still managed to produce a smooth attractive aerosol can. Extruded aluminium ensuring a smooth container body, unlike say a welded seem that would occur it was made from tinplated steel. Extrusion is a quicker, more efficient manufacturing process then simply welding tinplated steel. The only disadvantage to that is that tinplated steel does, in fairness, have a better finish than aluminium gives. The LYNX can appears to be a tad duller in comparison to say a Right Guard tinplated steel aerosol can. However LYNX have used bright colours to enhance the appearance of the can e.g. metallic blue or light green. The material is successful however and doesn’t react with the contents of the aerosol. The PET cap/lid/nozzle is a clever design also. It’s a plastic therefore water resistant, cheap and malleable. The lock (a twisting mechanism) gives a very visual representation of when the aerosol can be used i.e. it is noticeable when the can is locked and unlocked. The designer has ensured that there is a right amount of grip to help its user to perform an easy locking task.

It has come to my attention however, how quick the average aerosol’s product life cycle consists of. For such a feat of engineering to be considered to be a throw away item seems a bit of a waste. Other body sprays such as aftershaves and perfumes use a similar system of having a dip tube and valve to let out bits of its contents. However, they do not use a compressed gas or compressed container. It seems odd that some items do not have to use dangerous flammable gases and aerosols do. Maybe in the future someone will design an answer to safer aerosol can. However one advantage that the aerosol can does hold is that it has recently become recyclable which is important to the value of every product design. If something is recyclable it can be reused. To conclude, I think that LYNX have designed a reliable, purposeful and most importantly easy to use aerosol can that looks and feels great and incorporates the element of safety into its final product design.