Aerosol Spray Cans :: essays research papers fc

Aerosol Spray CansSpray cans start an aerosol, the technical term for a very fine sprayer.They do this by means of a pressurized propellant, which is a liquid that boilsat everyday temperatures. Inside the can, a layer of volatilised pressure increased,and eventually it becomes so high that boiling stops. when the nozzle is pressed,the float pressure forces the harvest-home up the tube in the can and pop of the nozzlein a spray or foam. The propellant may emerge as well b arely, now under lesspressure, it at one time evaporates.First patented in the US in 1941, aerosol spray cans have been used asconvenient packages for an ever increasing hustle of products including paints,insecticides, and shaving cream to name a few. The can is filled with theproduct to be sprayed and the propellant, a compressed go down on such as butane orFreon. The gas is partly liquefied by the pressure in the can, but there is alayer of free gas above the liquid. As the can empties liquefied gas v aporizesto fill the space.The valve is normal held shut by the pressure in the can, and by thecoil spring directly downstairs the valve nucleotide. When the push button is pressed, itforces the valve stem down in its housing, uncovering a small a small hole whichleads up through the stem to the nozzle in the button. This allows the productto be forced up the skirt tube by the gas pressure in the can. The nozzle is shape to give a spray or a continuous stream.To produce a fine mist, a propellant is used which mixes with theproduct. The two consecrate the nozzle together and the propellant evaporates a soonas it reaches the air, rupture the product in to tiny droplets. The sametechnique used with a more adhesive liquid and a wider nozzle results in a foam.For a continuous stream of liquid or more viscous material, a nonmixingpropellant is used, and the dip tube reaches into the product.The widespread use of aerosol cans using Freon as the propellant ledscientists to believe by t he previous(a) 1970s that the ozone layer in the upperatmosphere, which filters out harmful ultraviolet light radiation from the sun, couldbe destroyed by the large quantities of fluorocarbons in the gas being releaseinto the air. Federal controls were introduced to ban the use of Freon, andother propellants are now employed, notably butane which, however is dangerouslyflammable.Among young people in United States, conventional drug or alcohol abusehas effrontery away-for an increasing number of teen-agers-to a practice called