Old Candles


Modern Candles

Types of Candles

Pillar Candles are solid and self standing. Their shapes are typically round, but also come in square,     rectangular, hexagonal, and other designs. Some may have more than one wick. Heat resistant candle bases or stands must be used.           Floating Candles have a low, stable profile and are designed to float on water. They vary in form from simple, smooth designs to elaborate, realistic shapes.            Votive Candles are normally 2 1/2" high and usually square or cylindrical in shape. They are burned safely in small, heat resistant, glass containers to control the liquefied wax, as the candles burn.

Taper or Dinner Candles as they are also called, are usually 3/4" to 1" in diameter, ranging from 6" - 18" tall. Tapers need to be securely set in an appropriately designed candle holder, which will keep them in an upright position for proper and safe burning.            Container or Filled Candles are non-flammable, heat resistant containers which are filled with wax and  wick. Containers such as heat resistant glass jars and ceramic pottery are commonly used.              Tealight Candles are usually about 1 1/2" in diameter and around 3/4" high inside a cylindrical metal container. These small filled candles are used in food warmers or as candles in a tealight holder.

Gel Candles are produced from gelled mineral oils or gelled, synthetic hydrocarbons. They are transparent, rubbery and are usually poured into various shaped containers. Gels can also be made rigid enough to retain and support their own shape.             Specialty Candles may be found in any three dimensional shape imaginable. They can be molded or sculpted by hand and are mostly for decorative use.                   Luminaria Candles are for use outdoors. They are placed in a container which is filled with sand.

THE SCIENCE OF CANDLES

Candle Science

There’s a lot of chemistry and physics behind the beauty and light of a candle flame. In fact, scientists have been fascinated by candles for hundreds of years.

In 1860, Michael Faraday gave his now-famous lecture series on the Chemical History of a Candle, demonstrating dozens of scientific principles through his careful observations of a burning candle.

In the late 1990s, NASA took candle research to new heights, conducting space shuttle experiments to learn about the behavior of candle flames in microgravity.

Scientists in universities and research laboratories around the world continue to conduct experiments with candles to learn more about candle flames, emissions and combustion.

And, of course, thousands of students every year investigate the principles of heat, light and combustion through school science projects involving candles

How Candles Burn

All waxes are essentially hydrocarbons, which means they are largely composed of hydrogen (H) and carbon (C) atoms.

When you light a candle, the heat of the flame melts the wax near the wick. This liquid wax is then drawn up the wick by capillary action.

The heat of the flame vaporizes the liquid wax (turns it into a hot gas), and starts to break down the hydrocarbons into molecules of hydrogen and carbon. These vaporized molecules are drawn up into the flame, where they react with oxygen from the air to create heat, light, water vapor (H₂O) and carbon dioxide (CO₂).

Approximately one-fourth of the energy created by a candle’s combustion is given off as heat radiates from the flame in all directions. 

Enough heat is created to radiate back and melt more wax to keep the combustion process going until the fuel is used up or the heat is eliminated.

It takes a few minutes when you first light a candle for this combustion process to stabilize. The flame may flicker or smoke a bit at first, but once the process is stabilized, the flame will burn cleanly and steadily in a quiet teardrop shape, giving off carbon dioxide and water vapor.

A quietly burning candle flame is a very efficient combustion machine. But if the flame gets too little or too much air or fuel, it can flicker or flare and unburned carbon particles (soot) will escape from the flame before they can fully combust.

The wisp of smoke you sometimes see when a candle flickers is actually caused by unburned soot particles that have escaped from the flame due to incomplete combustion.

The Colors of a Candle Flame

If you look closely at a candle flame, you’ll see a blue area at the base of the flame. Above that is a small dark orange-brown section, and above that is the large yellow region that we associate with candle flames.

The oxygen-rich blue zone is where the hydrocarbon molecules vaporize and start to break apart into hydrogen and carbon atoms. The hydrogen is the first to separate here and reacts with the oxygen to form water vapor. Some of the carbon burns here to form carbon dioxide.

The dark or orange/brown region has relatively little oxygen. This is where the various forms of carbon continue to break down and small, hardened carbon particles start to form.

As they rise, along with the water vapor and carbon dioxide created in the blue zone, they are heated to approximately 1000 degrees Centigrade.

At the bottom of the yellow zone, the formation of the carbon (soot) particles increases. As they rise, they continue to heat until they ignite to incandescence and emit the full spectrum of visible light. Because the yellow portion of the spectrum is the most dominant when the carbon ignites, the human eye perceives the flame as yellowish. When the soot particles oxidate near the top of the flame’s yellow region, the temperature is approximately 1200^o C.

The fourth zone of the candle (sometimes call the veil) is the faint outside blue edge that extends from the blue zone at the base of the flame and up the sides of the flame cone. It is blue because it directly meets with the oxygen of the air, and is the hottest part of the flame, typically reaching 1400^o C (2552^o F).

Why a Candle Flame Always Points Up

When a candle burns, the flame heats the nearby air and starts to rise. As this warm air moves up, cooler air and oxygen rush in at the bottom of the flame to replace it.

When that cooler air is heated, it too rises up and is replaced by cooler air at the base of the flame.

This creates a continual cycle of upward moving air around the flame (a convection current), which gives the flame its elongated or teardrop shape.

Because “up” and “down” are a function of the earth’s gravity, scientists wondered what a candle flame would look like in outer space, where the pull of gravity is minimal and there really isn’t an up or down.

In the late 1990s, NASA scientists ran several space shuttle experiments to see how candle flames behaved in microgravity. As you can see from the NASA photos below, a candle flame in the microgravity is spherical instead of its elongated shape on Earth. Without gravity, there’s no “up” direction for warm air to rise and create a convection current.

A candle flame in normal gravity

A candle flame in microgravity

HISTORY OF CANDLES

Candles have been used for light and to illuminate man's celebrations for more than 5,000 years, yet little is known about their origin.

It is often written that the first candles were developed by the Ancient Egyptians, who used rushlights or torches made by soaking the pithy core of reeds in melted animal fat. However, the rushlights had no wick like a true candle.

Early Wicked Candles

The Egyptians were using wicked candles in 3,000 B.C., but the ancient Romans are generally credited with developing the wicked candle before that time by dipping rolled papyrus repeatedly in melted tallow or beeswax. The resulting candles were used to light their homes, to aid travelers at night, and in religious ceremonies.

Historians have found evidence that many other early civilizations developed wicked candles using waxes made from available plants and insects. Early Chinese candles are said to have been molded in paper tubes, using rolled rice paper for the wick, and wax from an indigenous insect that was combined with seeds. In Japan, candles were made of wax extracted from tree nuts, while in India, candle wax was made by boiling the fruit of the cinnamon tree.

It is also known that candles played an important role in early religious ceremonies. Hanukkah, the Jewish Festival of Lights which centers on the lighting of candles, dates back to 165 B.C. There are several Biblical references to candles, and the Emperor Constantine is reported to have called for the use of candles during an Easter service in the 4th century.

Middle Ages

Most early Western cultures relied primarily on candles rendered from animal fat (tallow). A major improvement came in the Middle Ages, when beeswax candles were introduced in Europe. Unlike animal-based tallow, beeswax burned pure and cleanly, without producing a smoky flame. It also emitted a pleasant sweet smell rather than the foul, acrid odor of tallow. Beeswax candles were widely used for church ceremonies, but because they were expensive, few individuals other than the wealthy could afford to burn them in the home.

Tallow candles were the common household candle for Europeans, and by the 13th century, candlemaking had become a guild craft in England and France. The candlemakers (chandlers) went from house to house making candles from the kitchen fats saved for that purpose, or made and sold their own candles from small candle shops.

Colonial Times

Colonial women offered America's first contribution to candlemaking, when they discovered that boiling the grayish-green berries of bayberry bushes produced a sweet-smelling wax that burned cleanly. However, extracting the wax from the bayberries was extremely tedious. As a result, the popularity of bayberry candles soon diminished.

T

he growth of the whaling industry in the late 18th century brought the first major change in candle making since the Middle Ages, when spermaceti -- a wax obtained by crystallizing sperm whale oil -- became available in quantity. Like beeswax, the spermaceti wax did not elicit a repugnant odor when burned, and produced a significantly brighter light. It also was harder than either tallow or beeswax, so it wouldn't soften or bend in the summer heat. Historians note that the first "standard candles" were made from spermaceti wax.

19th Century Advances

Most of the major developments impacting contemporary candlemaking occurred during the 19th century. In the 1820s, French chemist Michel Eugene Chevreul discovered how to extract stearic acid from animal fatty acids. This lead to the development of stearin wax, which was hard, durable and burned cleanly. Stearin candles remain popular in Europe today.

In 1834, inventor Joseph Morgan helped to further the modern-day candle industry by developing a machine that allowed for continuous production of molded candles by using a cylinder with a movable piston to eject candles as they solidified. With the introduction of mechanized production, candles became an easily affordable commodity for the masses.

Paraffin wax was introduced in the 1850s, after chemists learned how to efficiently separate the naturally-occurring waxy substance from petroleum and refine it. Odorless and bluish-white in color, paraffin was a boon to candlemaking because it burned cleanly, consistently and was more economical to produce than any other candle fuel. Its only disadvantage was a low melting point. This was soon overcome by adding the harder stearic acid, which had become widely available. With the introduction of the light bulb in 1879, candlemaking began to decline.

The 20th Century

Candles enjoyed renewed popularity during the first half of the 20th century, when the growth of U.S. oil and meatpacking industries brought an increase in the byproducts that had become the basic ingredients of candles – paraffin and stearic acid.

The popularity of candles remained steady until the mid-1980s, when interest in candles as decorative items, mood-setters and gifts began to increase notably. Candles were suddenly available in a broad array of sizes, shapes and colors, and consumer interest in scented candles began to escalate.

The 1990s witnessed an unprecedented surge in the popularity of candles, and for the first time in more than a century, new types of candle waxes were being developed. In the U.S., agricultural chemists began to develop soybean wax, a softer and slower burning wax than paraffin. On the other side of the globe, efforts were underway to develop palm wax for use in candles.

Today's Candles

Candles have come a long way since their initial use. Although no longer man's major source of light, they continue to grow in popularity and use. Today, candles symbolize celebration, mark romance, soothe the senses, define ceremony, and accent home decors — casting a warm and lovely glow for all to enjoy.