Basic introduction
Solid lighting products made of wax are usually made into a cylindrical shape with a cotton yarn core inside, called a candle wick. The yarn core is burned to emit light. The appearance of ordinary candles is cylindrical, solid, and milky white. No matter what kind of candle, it feels smooth, is difficult to dissolve in water, and is less dense than water.
Candles are often paired with candlesticks for decoration. In addition, some containers can also play the role of candlesticks, such as glassware for floating wax, and small incense burners for lighting wax and essential oils. Bamboo tubes and so on. At present, in addition to serving candles, candlesticks are also used as part of home decoration.
Main classification
There are many types of candles produced. According to the purpose of use, they can generally be divided into two categories: daily lighting candles (ordinary candles) and craft candles (special purpose candles). Lighting candles are relatively simple, usually white rod-shaped candles. Craft candles can be subdivided into many types. First of all, they can be divided into two categories: jelly craft candles and aromatherapy candles. Generally, various colors appear due to the addition of ingredients (such as birthday candles), and the shapes are also made into various forms according to needs (such as spiral, digital shapes, etc.), which can integrate novelty, decoration, appreciation, and functionality.
In addition, candles can also be divided into two types: rough wax and smooth wax. Generally, rough wax has a smell and a layer of white frost on it. Different rough waxes will bring different smells, such as You can put some lavender-scented candles in the bedroom to have a hypnotic and calming effect. You can put ocean-scented candles in the bathroom. In summer, you can also put some pine-scented candles to repel mosquitoes; glossy wax has no smell, and wax The body surface is very smooth, making it easy to create beautiful shapes.
According to the shape, candles can generally be divided into extruded cylindrical wax, pointed bamboo wax, torch wax, floating wax, round head wax, flat head wax, etc., and there are many colors. Some of these candles are more particular when used, such as sharp bamboo wax, which is suitable for inserting in the candle holder and placed in the middle of the dining table during meals. It is especially commonly used in Western food. If the home decoration is European style, it can also be placed in the living room as a Ornaments. Floating wax is often seen in bars. Pour water into a container and put the floating wax on the water, and it will float on the water. It has a unique atmosphere under the dim candlelight. Floating wax is often used in the homes of young people, especially between couples. Not only sharp bamboo wax can be used for candlelight dinners, but floating wax will also bring good effects.
In addition, the same kind of candles are also available in many sizes. For example, extruded cylindrical wax has four sizes: 8×25 cm, 8×20 cm, 7×15 cm, and 7×10 cm.
Historical development
It is now generally believed that candles originated from torches in primitive times. Primitive people applied fat or wax on bark or wood chips, tied them together, and made candles. It became a torch for lighting. There are also legends that in the ancient pre-Qin period, some people tied mugwort and reeds into a bunch, then dipped them in some grease and lit them for lighting. Later, some people wrapped a hollow reed with cloth, filled it with beeswax, and lit it.
The beeswax that appeared in about the 3rd century BC may be the prototype of the candles seen today. In the West, for a period of time, bees were kept in monasteries and used to make beeswax. This was mainly due to Catholicism. It is believed that beeswax is a symbol of virgin conception, so beeswax is regarded as the light of purity and is enshrined on the altar of the church. Judging from the existing literature, beeswax was produced in my country at roughly the same time as the West. Japan introduced this kind of candle from my country during the Nara Period (710-784 AD).
The popularity of candles has gone through a long historical period. "Xijing Miscellaneous Notes" records that during the Han Dynasty, candles were among the tributes paid by South Vietnam to Emperor Gao. Some say that fires were banned during the Cold Food Festival. The king rewarded officials above marquis and high-ranking officials with candles, indicating that candles were extremely rare at that time. During the Southern and Northern Dynasties, candles were slightly more commonly used, but they were mainly used in the upper class society, not for ordinary people's homes. In the Tang Dynasty, it was also recorded that candles were among the tributes in Jinzhou. In addition, officials in the Tang Dynasty also set up an official to manage the palace candles. The Song Dynasty recorded that in the border trade with Xixia at that time, candles were among the items traded. Candles are a tool used in foreign trade and foreign exchange, which shows that although they were more commonly used at that time, they were still relatively precious. After the Ming and Qing Dynasties, candles gradually entered the homes of ordinary people, and people used them more in daily life. However, ordinary lamps, such as oil lamps and torches, still cannot be compared with candles.
Compared with modern candles, ancient candles had many shortcomings. Li Shangyin, a poet of the Tang Dynasty, wrote a poem: "Why should I cut the candles from the western window?" Why did the poet cut the candle? At that time, the candle wick was made of cotton thread and stood upright in the center of the flame. It could not be burned out and became charred, so the remaining ends of the candle wick had to be cut off with scissors from time to time. This is undoubtedly a troublesome thing. In 1820, the Frenchman Jean Bachier invented a candle wick made of three cotton threads, which naturally loosened the candle wick when it burned, and the end just tilted to the outside of the flame, so it could burn completely.
But candles still need to be further improved. Their materials are usually animal fats with many shortcomings. The people who solved this problem were Michel Eugene Chevreul and others. . Between June and July 1809, French chemist Michel Eugène Scheffler received a letter from a textile factory asking him to analyze and determine the composition of a soft soap sample they sent.
He thought about this letter for a long time and thought: To study soap, it seems that we have to start with raw material oil. In a school experiment with very simple and simple equipment, he studied various oils and fats needed to be used in the saponification process. After a lot of experiments, he discovered for the first time the fact that in all oils, regardless of their source, fatty acids account for 95%, and the remaining 5% is glycerol generated during the saponification process. Through research, he clarified the nature of the saponification process. At the same time, he also made a major discovery: the candles made of grease at that time contained glycerin, and the flames contained smoke when burning, which gave them an unpleasant smell. If stearic acid is used instead to make a candle, it will not only have a bright flame when burning, but also almost no black smoke and will not pollute the air. Scheffler told Joseph Louis Gay-Lussac of his discovery and suggested that the two of them work together to study how to specifically solve this problem. They used strong alkali to saponify the oil, and then decomposed the resulting soap with hydrochloric acid to extract stearic acid. This is a white substance that feels greasy to the touch. Candles made from it are soft and cheaper. In 1825, Scheffler and Guy-Lussac obtained a patent for the production of paraffin stearate candles. The emergence of paraffin stearate candles created a new era in the history of human lighting. Later, someone discovered large oil fields in North America, and a large amount of paraffin wax could be extracted from the oil. Therefore, ideal candles were popularized and promoted around the world.
In ancient times, when electricity was not yet used, the lighting function of candles was particularly important. But today, with the rapid development of high technology, people generally no longer use candles in their daily lives. Candles are given more emotional colors, such as lovers' appointments, birthday dinners, mourning for the dead, prayers for the future, etc. Especially on anniversaries and festive days, people will light candles. In addition, candles are often used as supplies for physical or chemical experiments.
Raw materials
The main raw material of candles now is paraffin. Paraffin is obtained from the waxy fraction of petroleum by cold pressing or solvent dewaxing. It is a product of several higher alkanes. The mixture, mainly n-docosane (C22H46) and n-octadecane (C28H58), contains about 85% carbon elements and about 14% hydrogen elements. The added auxiliary materials include white oil, stearic acid, polyethylene, fragrance, etc. Among them, stearic acid (C17H35COOH) is mainly used to improve the softness. The specific addition depends on the type of candle produced.
When a candle burns, the combustion products of n-docosane and stearic acid are carbon dioxide and water. The chemical equations of the reactions are 2C22H46 + 67O2→44CO2 + 46H2O and C17H35COOH + 26O2→18CO2 + 18H2O. When a candle is lit, the initial burning flame is small and gradually becomes larger. The flame is divided into three layers (outer flame, inner flame, and flame core). The core of the flame is mainly candle vapor, with the lowest temperature. The paraffin in the inner flame is not fully burned, and the temperature is higher than the core of the flame. Because there are some carbon particles, the flame is the brightest. The outer flame is in full contact with the air, burning fully, and the temperature is the highest. Therefore, it should be Quickly put a match stem flatly into the flame and take it out after about 1 second. The part of the match stem that contacts the outer flame will turn black first.
Related Customs
Why do we need to blow out candles on birthdays? Some say this custom began in ancient Greece. In ancient Greece, people worshiped the moon goddess Artemis very much, and held a birthday celebration for her every year. On the altar, a cake made of flour and honey was placed, with many lighted candles on it. They compared the light emitted by candles to the clear glow of the moon to express their special worship of the moon goddess. Later, when the ancient Greeks celebrated their children's birthdays, they also liked to put cakes on the table, with many small lighted candles inserted on the cakes, and they also added the content of blowing out the candles. They believe that burning candles have some magical and secret power. When the birthday person silently makes a wish in his heart, he can blow out all the candles in one breath and his wish will come true. This custom has been passed down to this day and has become popular in many countries.
[Candle burning]
Light the candle and cover a cold and dry beaker above the candle
After 5 minutes, quickly invert the beaker and add a small amount to the beaker Shake the clarified lime water and observe
1. The inner wall of the beaker becomes blurred and water droplets are formed
2. The clarified lime water becomes turbid