Balloon

Background

A balloon is an air-tight bag made out of a light material that can be inflated with air or gas. Toy balloons are available in all kinds of shapes, sizes, and colors to delight children and adults at birthday parties and other festive occasions.

Balloons were first invented in France in the late 18th century. Two papermakers, Jacques and Joseph Montgolfier, discovered that when paper bags are filled with hot air, the bags rise. Quick to realize the potential of this, they began experimenting with balloons of various materials such as paper, cloth, and silk. They made the first public demonstration of a lighter-than-air balloon in June 1783, with a 35-foot (11 m) diameter balloon made of cloth lined with paper. Later that year, Jacques Charles flew a balloon made of silk coated with a rubber varnish and filled with hydrogen, a gas that is lighter than air. These early demonstrations attracted a great deal of excitement, and balloons were soon put to many uses in science, sport, and war.

The rubber toy balloon as we know it today is different from the early balloons in that it is made entirely of rubber. A practical way of making such formed rubber products required several discoveries and inventions. These developments took place gradually over the years since the first rubber factory in the world was established near Paris in 1803.

Natural latex is a mixture of small globules of rubber substance suspended in water (much like milk). When it is exposed to air, heat, or certain chemicals, it coagulates or clots together. The globules of rubber lump together and separate from the watery portion of the latex, eventually forming an elastic, solid material. To improve its strength, resilience, and resistance to hot and cold temperatures, rubber is vulcanized or cured by various methods, such as mixing with certain chemicals or treating with heat.

The idea of making a product out of rubber is an old one. The natives of South America created bottles and other articles by coating molds made of earth long before Europeans began experimenting with rubber in the mid-1700s. In 1830, the Englishman Thomas Hancock patented a process for creating products by pouring latex over molds or dipping molds into a latex mixture—the forerunner of the modern technique of producing dipped products such as rubber gloves and condoms.

In 1921, a method of retarding the coagulation of liquid latex was developed. This method enabled rubber makers to transport raw latex in a liquid form more easily to manufacturing centers around the world. This in turn led to new processes for making rubber goods. In the early 1920s, a number of patents were granted in England for processes that allowed molds to be dipped in liquid latex. In 1931, the first modern latex balloon was created by Neil Tillotson in his attic. He sold 15 of his "Tilly Cat" balloons (shaped like a cat's head, complete with whiskers printed on with dye) for the Patriot's Day parade in Massachusetts in April 1931, and formed a company that still makes balloons today.

Raw Materials

Although rubber can be made synthetically, natural latex is preferred for its great elasticity. It can be stretched to seven or eight times its original length and still return to its former shape. Synthetic rubber has not proven to be as elastic and resilient as natural latex.

Raw, natural latex is a white or yellowish opaque liquid, similar in appearance to milk. Latex is the secretion of certain plants, in particular the Hevea tree originally found in Brazil. The most important sources of natural rubber today are plantations in Malaysia and Africa.

Producers of rubber must harvest the raw material from these trees, which involves scoring the trees with shallow cuts and letting the sap ooze from the cuts into buckets. The latex is collected in large containers, filtered to remove foreign particles, and mixed with alkali to prevent coagulation. It is then shipped in liquid form to processing centers in different parts of the world.

Latex must be mixed with additives before it can be used in industrial processes. Certain chemicals are mixed in to achieve a desired thickness, rate of drying, and other properties. Other chemicals (collectively known as antidegradants) are added to slow the oxidation and decomposition of the rubber. To give it color, pigments are mixed into the latex. The pigments may be fine metal oxide powders or organic dyes.

The Manufacturing
Process

In essence, the process of making a toy balloon involves dipping a mold into liquid latex. The mold, or form, is shaped like a deflated balloon.

The earliest balloon forms were disposable, made from cardboard attached to dowels. Modern forms are reusable and usually made from stainless steel, aluminum, or porcelain. The forms must be smooth and polished. A number of such forms are attached upside down to a board or rack. The boards are moved mechanically from one station to another in the factory.

To be efficient in terms of cost and number of balloons produced, balloon manufacture has become a highly automated, continuous loop process. Balloons are made in batches, all of the same color and size, since changing the color and form is time-consuming and requires manual intervention. Manual intervention is usually only needed for setting up a run and then later for packaging the finished product, and for dealing with occasional mechanical problems that may arise.

Preparing the latex

• 1 Prior to its use, the latex may need to be colored. This involves mixing a pigment into the latex. It may be done at the balloon factory, or the balloon maker may purchase already-pigmented latex from a supplier.
• 2 The latex must be poured into tanks into which the forms will be dipped. The tanks are kept at a certain temperature and may include stirring mechanisms to keep the latex circulating to avoid settling.

Dipping the forms

• 3 The balloon forms are first heated, then immersed in a tank of coagulant solution for a few seconds. When the forms are immersed in the liquid latex, the coagulant will cause the rubber to gel in a thin sheet around the forms. A commonly used coagulant solution is a mixture of water, a calcium-based salt, soap, and talc powder. The salt is the actual coagulant; the soap helps the latex spread in an even film, and the talc helps ease the removal of the rubber from the forms in a later step.
• 4 The forms are heated to a temperature between 100°F (38°C) and 200°F (93°C), and then immersed in a tank of colored latex. The coagulant causes the latex to coat the forms. The longer the forms are left in the tank, the thicker the coating that sticks to them. For balloons, a very thin layer of latex is desired, so the forms are immersed only for a few seconds. The forms must be inserted and removed at carefully controlled speeds to avoid trapping air bubbles and to achieve an even, thin coating.

Making the ring

• 5 A lip is formed on the neck of the balloon by rolling the edges of the rubber using brushes or rollers. This creates the ring seen around the opening of the balloon.

Removing excess coagulant

• 6 Next, the forms are immersed in a tank of leaching solution (often plain water) to dissolve and leach away excess coagulant from the rubber.

Curing the rubber

• 7 The rubber on the forms must be dried and cured. The method used varies among manufacturers. Some balloon makers use a latex that already contains a vulcanizing agent, in which case the rubber is dried at a moderate temperature. Other makers induce vulcanization by putting the rubber-coated forms into an oven and curing for as long as an hour.

Removing the balloons

• 8 The balloons are then mechanically removed from their forms. One approach is to blow them off using a spray of water or air and collecting the balloons in a basket or net.
• 9 If the balloons are removed using a spray of water, they are next placed in a centrifuge, where excess water is removed by spinning the balloons around at high speed.
• 10 The balloons are then dried in large tumble dryers.

Printing and packaging

• 11 Next, the balloons may either be packaged, or first printed and then packaged. If they are packaged directly, they are moved on a conveyor belt past a counting device and placed into bags. When an appropriate number of balloons has been placed in each bag, the bags are sealed.
• 12 Printing designs on balloons, such as logos or faces, actually involves several steps. First, the balloons must be inflated in order to allow even printing. This requires a worker to manually place each balloon on the inflating device. Next, a pattern is carefully printed on each balloon. Finally, the balloons are removed and passed on to the packaging stage.

Quality Control

The balloon manufacturing environment must be strictly controlled in order to achieve high quality and consistency. Throughout the manufacturing process, computer-based instrumentation records and controls air humidity, air temperature, latex tank temperature, the temperature in the ovens, dryers, and other parameters.

The latex and other chemicals used in the process must be carefully formulated for specific properties, and carefully maintained. For example, the latex must have certain viscosity and speed of drying. The tanks in which it is held must have devices to keep the latex circulating to avoid forming a "skin," and to prevent ingredients from settling.

Byproducts/Waste

It is in the manufacturers' best interests to waste as little rubber as possible because the cost of latex is high compared to the selling price of individual balloons. Balloon makers also reclaim much of the coagulant that ends up in the leaching solution. Unfortunately, what is not reclaimed ends up as liquid waste in the environment. The amount of chemical waste that can be released by a factory is regulated by government laws. Balloons also result in some waste after they are manufactured because they are invariably thrown away after they deflate or pop. However, because latex is natural, it eventually breaks down into other substances.

Safety Concerns

Toy balloons can be a source of joy, but they can also be unexpectedly hazardous. Young children have been known to die from accidentally choking on balloons. Latex balloons may also end up in water, where they eventually lose their color and can resemble jellyfish. Sea animals such as whales and turtles have attempted to eat them and have died because the latex clogs their digestive systems.

The Future

The toy balloon industry is very competitive. Manufacturers are constantly looking for ways to make the process more automatic and efficient, especially by reducing manual intervention. Currently the most labor-intensive portions are the printing and packaging steps. Increasing automation in these steps is an area for potential future improvement.

In recent years balloons made of metal films have become popular. The manufacturing process of these balloons is very different. They are made from a sandwich of two swatches of mylar—a polyester film—often circular in shape, which are sealed together around the edges. A small opening is left through which the balloon may be inflated. Because the material is initially flat, these balloons can be printed more easily than balloons made of rubber. The foil can be made very shiny and reflective, allowing for very bright designs. They are stronger and more durable than rubber balloons, but for some uses, this is also a disadvantage. For example, they cannot be twisted into various shapes nor can they be filled with water. The foil also takes much longer to degrade in the environment than rubber.

Where To Learn More

Books

Barlow, Fred W. Rubber Compounding: Principles, Materials, and Techniques. Marcel Dekker, Inc. 1988.

Coates, Austin. The Commerce in Rubber: The First 250 Years. Oxford University Press, 1987.

Hofmann, Werner. Rubber Technology Handbook. Oxford University Press, 1989.

—Renee M. Rottner

Balloon

A balloon is a type of aircraft consisting of a thin envelope filled with a gas less dense than the surrounding air. The envelope can be made of rubber, plastic, treated paper or cloth, or other material through which gases cannot seep. Ordinary party balloons are good models for most kinds of balloon. They are made of rubber that expands when air is blown into them. And the air from a person's breath used to inflate them is less dense than the surrounding air.

Balloon gases

A balloon rises in the air for the same reason that a cork floats in water. Just as a cork's density is less than the density of the surrounding water, so a balloon's density is less than the air around it. The lower-density object, then, is pushed upward by the surrounding higher-density medium.

It stands to reason, then, that the best gas to use in a balloon is the one with the lowest density: hydrogen. In fact, hydrogen was used in the construction of balloons for more than a century. But this gas has one serious drawback. It burns easily and, under the proper circumstances, can even explode. The tragic fire that destroyed the Hindenburg dirigible (airship) in 1937 occurred when lightning set fire to hydrogen gas inside it.

Because of hydrogen's flammability, the most popular gas for filling commercial balloons is helium, the second-least dense gas after hydrogen. Helium has 93 percent of the lifting capacity of hydrogen with none of its safety concerns. The problem is that helium is more expensive than is hydrogen. Still, balloons used for commercial and research purposes today almost always use helium as the lifting gas.

Another gas used in balloons is hot air. Hot air has the same chemical composition as ordinary air but, because of its temperature, is less dense that the air around it. Balloons used for sight-seeing and sport usually use hot air. The gondola (traveling compartment) below the balloon itself contains a heating unit that warms air and then pushes it up into the balloon.

Balloon guidance

Vertical (upward or downward) movement of a balloon is generally under human control. In a sight-seeing balloon, the operator can turn the heater on and off to produce more or less hot air. Changes in the amount of hot air make the balloon rise or fall. Vents in the balloon envelope also make it possible to control the amount of gas inside the balloon, therefore changing its vertical movement. The horizontal movement of a balloon is beyond human control, however. Once a balloon has left Earth's surface, its horizontal motion is dependent on wind currents.

History

Joseph (1740–1810) and Jacques Montgolfier (1745–1799) are considered the fathers of ballooning. In 1783, after a series of experiments, the brothers constructed a balloon large enough to carry two humans into the atmosphere, the first manned aircraft.

The suitability of balloons for making atmospheric observations soon became evident, and manned balloon trips soon became common. In 1804, for example, French physicist Joseph Louis Gay-Lussac (1778–1850) traveled to an altitude of 23,000 feet and collected a sample of air. He found that air at that altitude was identical to air at Earth's surface.

In his ascent, Gay-Lussac nearly reached the limits of manned balloon trips without special protection. In contrast, in 1863, two English scientists, James Glaisher and Henry Tracey Coxwell (1819–1900), traveled to a height of over 33,000 feet to study the properties of the upper atmosphere. At that height, the air is so thin that the two men nearly lost their lives.

The greatest of the early balloonists, however, was French meteorologist Léon Philippe Teisserenc de Bort (1855–1913). Over a three-year period between 1899 and 1902, de Bort launched 236 balloons with instruments designed to measure atmospheric conditions.

Scientists are now able to use life-support systems, such as those that are common in space flights, to travel to higher and higher reaches of the atmosphere. The current record is held by two Americans, Ross and Prather, who reached an altitude of 113,740 feet in 1961.

Applications of balloon flight

Balloons are used today primarily for two purposes: for collecting information needed for making weather forecasts and for scientific research. Weather balloons typically carry packages of instruments called radiosondes for measuring the temperature, pressure, density, and other

properties of air at some altitude. Each day, thousands of these radiosonde-carrying balloons (called balloonsondes) measure all possible characteristics of the atmosphere around the world. Meteorologists depend on this information for making short- and long-term weather forecasts.

Balloons are also used extensively for astronomical research. Their advantage is that they can take telescopes high enough into the atmosphere that they will not be affected by dust, water vapor, smoke, and other forms of air pollution. Telescopes with a diameter of up to three feet are placed on platforms which are supported by mammoth balloons as tall as eight-story buildings. These telescopes have been carried to altitudes of 120,000 feet.

The Russian mission to Venus in 1985 used two helium balloons to study the motion of the Venusian atmosphere. For 46 hours, they floated above Venus with an attached package of scientific equipment that analyzed the environment and transmitted information directly to Earth.

The success of balloons on Venus has raised the possibility of a similar mission to Mars. American scientists have designed a device consisting of a large hot-air balloon and a much smaller helium-filled balloon

joined to each other. During the day, the air balloon, heated by the Sun, would drift in the Martian atmosphere with a payload of instruments. At night, the air balloon would cool and descend to the ground, where it would stay, supported in the upright position by the smaller gas balloon. Thus, the same probe would perform the on-ground experiments at night and the atmospheric experiments during the day, traveling from one location to another.

[See also Aerodynamics; Aircraft; Buoyancy ]

balloon lighter-than-air craft without a propulsion system, lifted by inflation of one or more containers with a gas lighter than air or with heated air. During flight, altitude may be gained by discarding ballast (e.g., bags of sand) and may be lost by releasing some of the lifting gas from its container.

Although interest in such a craft dates from the 13th cent., the balloon was not actually invented until the late 18th cent., when two French brothers, Joseph and Jacques Étienne Montgolfier , experimented with inverted paper and cloth bags filled with heated air and, in 1783, caused a linen bag about 100 ft (30 m) in diameter to rise in the air. In the same year the Frenchmen Pilâtre de Rozier and the marquis d'Arlandes made one of the first balloon ascents by human beings, rising in a hot-air-filled captive balloon (i.e., one made fast by a mooring cable to prevent free flight) to a height of 84 ft (26 m). In 1766 the English scientist Henry Cavendish had shown that hydrogen was seven times lighter than air, and the usefulness of this gas in balloon ascension was demonstrated in Dec., 1783, by J. A. C. Charles of France, who with his associates successfully ascended in a hydrogen-filled balloon and traveled 27 mi (43 km) from the starting point.

The first ascent in England was made by James Tytler, a Scottish writer, in 1784, and in 1793 the French balloonist J. P. Blanchard made an ascent at Philadelphia. Blanchard, with Dr. John Jeffries, an American physician, also made the first sea voyage by balloon, crossing the English Channel in 1784. Among the noted balloon voyages of the 19th cent. was that made by the Swedish engineer S. A. Andrée , who, in 1897, attempted unsuccessfully to reach the North Pole by balloon. In the American Civil War and World War I, captive balloons were used to observe troop movements and to direct gunfire. Captive balloons, called barrage balloons, were used as obstacles against low-flying aircraft in World War II.

The helplessness of the free balloon in controlling direction led to the development of the dirigible balloon (see airship ). In 1932 the Swiss physicist Auguste Piccard , one of the major figures in 20th-century ballooning, ascended in a balloon with a sealed spherical gondola to a height of 55,500 ft (17,000 m); since then manned balloons have reached heights of 100,000 ft (30,500 m) and unmanned balloons have exceeded 140,000 ft (42,500 m). The Americans Ben Abruzzo, Maxie Anderson, and Larry Newman made the first transatlantic crossing in 1978, and in 1981 Abruzzo, Newman, Rocky Aoki, and Ron Clark crossed the Pacific. In Mar., 1999, Jacques Piccard, Auguste's grandson, and Briton Brian Jones made the first nonstop balloon flight around the world; the American Steve Fossett completed the first nonstop solo circumnavigation in July, 2002. Today high-altitude hydrogen balloons carry aloft radios and other instruments, used to transmit meteorological readings or to take photographs free from atmospheric distortion.

In contemporary sporting balloons, which use air heated by a small gas-fired burner, altitude is controlled by varying the temperature of the heated air. Hot-air balloons represent the fastest-growing segment of ballooning. Gas bags made with space-age materials are more durable and weigh far less than the traditional silk; heaters have similarly become more efficient. While ballooning remains dangerous, the hot-air balloon's slow response time offers a unique sensation of effortless motion through the atmosphere.

Bibliography: See A. Hildebrandt, Balloons and Airships (1976); J. P. Jackson and R. J. Dichtl, The Science and Art of Hot Air Ballooning (1977); B. Piccard and B. Jones, Around the World in 20 Days (1999).

bal·loon / bəˈloōn/ • n. 1. a brightly colored rubber sac inflated with air and then sealed at the neck, used as a children's toy or a decoration: the room was festooned with balloons and streamers | fig. his derision pricked the fragile balloon of her vanity. ∎  a round or pear-shaped outline in which the words or thoughts of characters in a comic strip or cartoon are written: a balloon reading “Ka-Pow!” 2. a large bag filled with hot air or gas to make it rise in the air, typically carrying a basket for passengers: a hot-air balloon. • v. [intr.] 1. swell out in a spherical shape; billow: the trousers ballooned out below his waist ∎  (of an amount of money) increase rapidly: the company's debt has ballooned in the last five years | [as adj.] (ballooning) ballooning government spending. ∎  swell dramatically in size or number: the public payroll ballooned from about 27,000 people to about 66,000 people ∎  (of a person) increase rapidly and dramatically in weight: I had ballooned on the school's starchy diet. 2. travel by hot-air balloon: he is famous for ballooning across oceans. • adj. resembling a balloon; puffed: a flouncy balloon curtain. ORIGIN: late 16th cent. (originally denoting a game played with a large inflated leather ball): from French ballon or Italian ballone ‘large ball.’

balloon Unsteerable, lighter-than-air craft, usually made of nylon. Balloons are used for recreation, scientific, and military purposes. Ballooning was the first means of human ‘flight’. Generally credited with the achievement are the French brothers Jacques and Joseph Montgolfier, who devised a hot-air balloon in which Jean François Pilâtre de Rozier and the Marquis d' Arlandes made the first ascent (November 21, 1783). Unmanned military, meteorological or other scientific balloons are usually filled with hydrogen, which is the least dense of all gases but dangerously flammable. Manned balloons are generally filled with safer helium gas or hot air. In the hot-air method, burning propane gas is used to heat the air through an opening in the bottom of the balloon, which is usually made of nylon fabric. On March 20, 1999 Bertran Piccard and Brian Jones competed the first non-stop flight around the world.

balloon.
1. Large ball, balloon, globe, or sphere placed above a column or pier as a termination.

2. Globe under a cross on a church spire or dome.

3. System of timber-framed construction common in Scandinavia and the USA in which the corner posts and studs are continuous in one piece from cill or sole-plate to roof-plate, the intermediate floor-joists being secured to them without mortises and tenons.

Bibliography

Condit (1968);
Giordano (1964);
F. Peterson (1992)

balloon balloon payment a repayment of the outstanding principal sum made at the end of a loan period, interest only having been paid hitherto; the idea is that the final payment represents much the largest part of the original loan.
when the balloon goes up when the action or trouble starts, probably with allusion to the release of a balloon to mark the start of an event.

balloon bəˈlōōn n.a large bag filled with hot air or gas to make it rise in the air, typically carrying a basket for passengers: a hot-air balloon.
when or before the balloon goes up informal when (or before) the action or trouble starts: we've got to get our man out of there before the balloon goes up.

balloon (bă-loon) n. an inflatable plastic cylinder of variable size that is mounted on a thin tube and used for dilating narrow areas in blood vessels or in the alimentary or urinary tracts. b. angioplasty see angioplasty.

balloon XVI. — Fr. ballon or It. ballone, augm. of balla ball (of Gmc. orig.); see -OON.

balloon •afternoon, attune, autoimmune, baboon, balloon, bassoon, bestrewn, boon, Boone, bridoon, buffoon, Cameroon, Cancún, cardoon, cartoon, Changchun, cocoon, commune, croon, doubloon, dragoon, dune, festoon, galloon, goon, harpoon, hoon, immune, importune, impugn, Irgun, jejune, June, Kowloon, lagoon, lampoon, loon, macaroon, maroon, monsoon, moon, Muldoon, noon, oppugn, picayune, platoon, poltroon, pontoon, poon, prune, puccoon, raccoon, Rangoon, ratoon, rigadoon, rune, saloon, Saskatoon, Sassoon, Scone, soon, spittoon, spoon, swoon, Troon, tune, tycoon, typhoon, Walloon •fortune, misfortune •vodun • veldskoen • honeymoon •forenoon • tablespoon • teaspoon •soupspoon • dessertspoon • Neptune •tribune • triune • opportune