Candles have been known and used for illumination since early civilization. For years, beeswax was commonly used as a natural wax for candles, cosmetics and food preservation sealing waxes. A typical candle is formed of a solid or semi-solid body of combustible waxy material, such as paraffin wax or beeswax, and contains a combustible fibrous wick embedded within the waxy material. When the wick of a candle is lit, the generated heat melts the solid wax, and the resulting liquid flows up the wick by capillary action and is combusted. At present, although many advanced illuminating devices are available, candles are still popularly used for decoration, as a scent-dispensing vehicle or on a special situation such as a holiday.
Over one hundred years ago, paraffin came into existence, parallel with the development of the petroleum refining industry. Paraffin is simply the leftover residue from refining gasoline and motor oils. Paraffin was introduced as a bountiful and low cost alternative to beeswax. In recent years, paraffin has become more costly and in less supply. Paraffin is presently the primary industrial wax for the following three uses: candles, cosmetics and sealing waxes.
Conventional candles are made from a wax material, such as paraffin. Such candles typically emit a smoke and can produce a bad smell when burning. Many people cannot accept such smell. In addition, a small amount of particles (“particles”) are often created when the candle burns. These particles may affect the health of a human when inhaled. Paraffin soot particles are similar to particles given off by burning diesel fuel, which include a number of polycyclic aromatic hydrocarbons that have been deemed toxic air contaminants.
In addition to these issues, paraffin wax is diminishing in supply as consumer demand increases. New petroleum technology does not produce by-product petro-waxes. This decrease in supply requires importation of petroleum waxes. This coincides with a huge ($2.5 billion) decorative candle market in the U.S.
There is a strong consumer need and demand for alternative natural waxes as an option to paraffin waxes that can be produced at a rate that is cost competitive with paraffin. Accordingly, it would be advantageous to have other materials that can be used to form clean burning base materials for forming candles. If possible, such materials would preferably be biodegradable and be derived from renewable raw materials. The candle base materials should preferably have physical characteristics, e.g., in terms of melting point, hardness and/or malleability, that permit the material to be readily formed into candles having a pleasing appearance and/or feel to the touch, as well as having desirable olfactory properties.
There are fundamental differences in the inherent properties of the renewable saturated triglycerides when they are compared to the petroleum based straight chain aliphatic hydrocarbons that make up paraffin wax. Triglycerides exhibit well-documented polymorphic behavior where as the aliphatic hydrocarbons of paraffin does not. Polymorphism means that there are multiple crystal forms of the material that can exist. In general under rapid cooling, less stable lower melting less dense crystals form initially, but given time and heat cycles the mobility of the molecules allow their rearrangement to higher melting, more stable and more dense crystal forms. This rearrangement can lead to the problems of cracking and blooming in candle produced from vegetable wax.
The inventions disclosed herein represent approaches to resolving the physical property limitations associated with vegetable and animal-based triglycerides when used as alternatives to paraffin waxes.