Candles were first invented thousands of years ago by the ancient people who lived during those times. Although nobody remembers who the actual inventor – or inventors –is, the impacts of their invention can still be felt millennia later.
For the longest time, candles were one of the few major sources of indoor illumination, alongside lamps. However, the candle-making industry began to experience a lot of changes. First of all, paraffin wax was introduced into the global market and it began to replace tallow candles in terms of demand and supply. Secondly, the electric light bulb was invented.
WHAT ARE CANDLES MADE OF?
Candles are made up of two main parts, the candlewax and the candle wick. The candle wax is usually made up of materials that are easily combustible, which can support burning and maintain a solid state at room temperature. However, under the influence of the high heat of a candle’s flame, the solid wax should be able to melt easily into a hot liquid form (which, when cooled, would solidify again).
Candlewax can be made from a variety of materials. The earliest known material used in making candlewax is tallow or fat obtained from the carcasses of cattle and other livestock. This fat is usually boiled down and poured into molds or containers – with a wick inserted into the middle – and left to solidify in order to form candles. Apart from tallow or fat obtained from the carcasses of animals and other livestock, other forms of candle wax include beeswax, soy wax and paraffin wax. All these type of waxes have their own unique properties which make them stand out from others. For instance, beeswax is generally regarded as high-quality wax. It does not bend easily under the action of heat and it does not burn down at a fast rate compared to other kinds of candles. Soy wax is also of good quality but it has a higher tendency to bend under the action of heat compared to beeswax. Paraffin wax is the most widely used kind of candle wax in the world right now and it is very popular because candle-makers prefer to work with it on an industrial scale. It is much easier to produce large quantities of candles using paraffin wax – which is both odorless and colorless – than any other type of candle wax.
THE MYSTERY BEHIND A CANDLE’S FLAME
The burning of a candle happens based on a simple mechanism (which every other source of fire follows). No fire or flame – no matter how small – can burn in the absence of oxygen and a source of fuel. Without oxygen, combustion will not happen and the source of fire will not even be ignited. In the same vein, when a fire burns without a proper fuel source, it will not be sustained.
When a fire burns in the presence of oxygen, however, there are certain things involved which will determine the quality of the flame. These factors also apply in the instance of burning candles and they are displayed by the type of flame formed. When a fire burns well, in the presence of a proper amount of oxygen, and the combustion that takes place is complete, the flame burns blue. When combustion is not complete, however, the candle’s flame may burn yellow or red. The yellow flame burns hotter than the red flame because combustion is more complete in that case, however, the blue flame burns the hottest. Usually, it is common to observe all these colours – i.e. blue, yellow and red – in a single flame of a burning candle, and each coloured zone will represent either zones of complete combustion (the innermost part of the flame that burns blue. It is also the part of the flame that burns hottest), and zones of incomplete combustion (these zones comprise the yellow coloured part of the flame – closest to the blue coloured zone – and the red coloured part of the flame, which is usually found at the outermost part).
Also, when some candles burn, a lot of smoke is usually produced. This smoke usually contains gaseous products of combustion, which get into the atmosphere and affect the quality of air.
SHOULD A CANDLE PRODUCE SMOKE WHEN BURNING?
Ideally, no candle should produce smoke when burning. Aside from the fact that smoke produced from a burning candle is not healthy – as it could trigger respiratory illnesses and diseases such as asthma attacks, and could also result in suffocation in extreme cases – a burning candle which produces smoke is also exhibiting signs of low quality. This is because when a candle emits large quantities of smoke when burning, it usually signifies that either something is wrong with the candle wax or the candle wick (or both).
The candle wax and candle wick are the two major parts of a candle which can influence its ability to burn very well (or its ability to produce smoke when burning). Candle wax of high quality will melt very well without any presence of physical or chemical impurities, which may cause the production of smoke when the candle is lit. Wax of high quality will not just result in the production of little to no quantity of smoke and soot, it will also lead to low rate of burning of the candles, thus allowing it to last longer and burn for a longer period of time.
Similarly, when a candle has a wick which is of low quality, it may produce high quantity of smoke when burning. Candle wicks are usually made up of braided fibers, such as wool, which have been treated and curled in a unique manner in order to ensure the proper burning of candles (and the proper disintegration of the wick during candle-burning).
Other factors which can result in a candle producing large quantities of smoke when burning are mainly external, and the most common one amongst them is the influence of wind. If a candle is burning where the wind is strong, it may produce more smoke and soot as a result of incomplete combustion (smoke production is generally a side effect of incomplete combustion).