Archive for the ‘Firework Colours’ Category
Colours Of The Rainbow – Created In A Chemistry Lab!!
As a young child, I was always fascinated by fireworks but as my main interest was in all things medical, I was not in the Chemistry crew and therefore much of my knowledge about fireworks has come from researching the subject for my job.
There is a little bit of all of us that has that two year old child inside us shouting out ‘but why?’ or ‘but how do they do that’ and here are my attempts to take the mystery out of the colours in fireworks today.
Many of you may know that fireworks were first discovered in China many hundreds of years ago by pure accident. As the good people of China all cooked on open fires way back in time, every time anything was spilt onto the coals, the effects of heat and fire would become apparent. In the first instance, it is said that a cook in the first century accidentally combined charcoal, sulphur and salt peter (potassium nitrate – which was a common ingredient in the curing of meats particularly salt beef and pork for bacon) and the resulting mini explosion caused some interest and so began the history of fireworks and the continuing fascination.
Of course Chinese medicine has always included some strange and often powerful chemicals commonly found in the home so it was not unheard of for people to use them in cooking, inadvertently or otherwise.
Over the years, there has been little change in regards to the chemicals utilised to create the colours and here are the most commonly used:
• Electric White: White-hot metal flakes
• Orange: Calcium salts
• Bright Red: Strontium Carbonate
• Turquoise: Copper Chloride
• Purple: Strontium (red) & Copper (blue)
• Silver Sparkle: Burning Aluminium or Magnesium flakes
• Green: Barium Chloride
• Gold: Glowing Iron or Charcoal powder
• Yellow: Sodium Chloride
Fireworks have been used to light up the night for centuries for aesthetic and entertainment purposes. However, in the recent times, colour has been introduced into displays.
Today, pyro enthusiasts tend to choose the colour that suits the purpose of the display. For example, the red, blue and silver/white colours were most popular colours during the Queen’s Diamond Jubilee. Of course, these are primary colours for the United Kingdom and its national flag.
In the beginning of fireworks, yellows and oranges were the only colours that could be produced using steel and charcoal. Later in their development, chlorate’s were added which produced red and green colours. From this moment, there were greater quests to make fireworks that not only give loud bangs but colours.
Better production of colours in fireworks involves two main mechanisms:
Incandescence is simply the light produced from heat. The heat makes the substance to grow hot and glow. This result in the emission of infrared, then red, orange, yellow and `white ‘light.
The production of these colours relates to the level of the temperature. Deep green and blue colours require much higher temperature – ones which are not practicable for fireworks and cannot be formed using this method. Instead they are produced through the mechanism of luminescence.
Luminescence is light produced through energy source. This is a more complex method but suffice to say that the breakthrough in this process has helped the pyrotechnics in the production of blue colours.
The 64 shots Cobolt blue from Epic fireworks is a good example. When it bursts, it produces loud sapphire stars of blue colours only. It is this colour that makes it a bit more expensive than others in the same category.
We are led to believe that they are working towards producing a piece that will emit deep forest green colours. This, when achieved, will be an advancement not only in the fireworks industry but also in the fields of entertainment.
The field of Fireworks has come of age and the spectators have developed unquenchable taste for colourful display.