Aerosols have many uses

In the home




How many uses are there in the home for aerosols? Deodorants and hairspray are two. Can you find more?


On the farm



What uses can you think of for aerosols on the farm or at the vets. The picture shows a paint marker spray for cattle to show whether they are ready to mate or pregnant.


In medicine




A visit to the chemists will show lots of medical uses. This picture shows an asthma inhaler. This aerosol is unusual because it creates a fine mist made from tiny droplets that can deliver a drug right into the lungs. Normally aerosols make larger droplets to stop this happening. Another feature is that it delivers a measured dose for each press. It has a specially designed valve to do this.


In industry



Industrial uses include cleaner sprays like this one and lubricant sprays.



This is a food grade lubricating spray made from edible oils. Mineral oils are not allowed in food factories because they are toxic.



On the pitch


In World Cup and Premiership matches the referee uses a foaming spray that looks like shaving foam, but is a simple foam that disappears within about thirty seconds; just enough time for a free kick. The defenders must not move over the line.





Photographs: Hassan Ammar/AP


The kick taker can't move the ball either.


At night




Aerosols can spray reflective coatings onto fabrics and even animals. The spray contains transparent micro beads that reflect light back to its source. This is called retro reflection. Cat's eyes in the road work the same way with large glass spheres. White lines in the road also work the same way. The white paint contains tiny glass beads that are retro reflective.

Retro reflective coatings can be sprayed onto animals to avoid road accidents.



Images: Albedo100


In the kitchen


Aerosol sprays for olive oil allow for use of very small amounts.
The can keeps light and air away from the oil to help preserve it.
In food aerosols the product (olive oil) and the propellant (in this
case compressed nitrogen) are kept separate by a bag inside the can.
You can find out more about this on page 4.

Image: Lindal















At sea




For small boats this aerosol horn can be heard a mile away.


Image: Falcon














Questions

1. Make a list of the products that can be delivered by aerosols. Are there any of these that would be difficult or wasteful to use in another type of container?

2. What advantages does an aerosol have for the lubricant spray in the food factory?

CLICK FOR ANSWERS


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History

The first aerosol can that is similar to modern cans was made in Norway by an engineer called Erik Rotheim back in 1929. In 1998 the Norwegian postal service issued a stamp to commemorate it. You can just see the 1929 date on the stamp.

The first cans were heavy and almost completely hand made. Today's cans use steel sheets  less than 0.2 mm thick or aluminium  made on high speed automatic machines. 1,400,000,000 (1.4 billion) cans are made each year in the UK alone.

Erik's first product was an aerosol wax for skis. He might have been happy to know that the latest high tech aerosol is doing the same job.



Erik did not make any money from his invention and sold the patent. The aerosol became popular in America in the 1940s and 1950s and the rest is history.



UK Success

The UK is the biggest aerosol maker in Europe and exports half of the 1.4 billion cans made here each year. The industry employs 5000 people directly and many more in support industries.

Recycling

Today empty aerosols can be recycled in your green bin. The steel and aluminium recovered has a very high value and uses less energy to process into metal products than new metal made from mined ores. The aluminium in aerosols is especially pure and valuable. Always empty aerosols before recycling.












Image: Wikipedia

The optics of retro reflection in a sphere. Light coming into the sphere is refracted (bent) on the way in and internally reflected. It leaves in the same direction as it came in. On the road it means that the light reflects straight back to the driver.