Rubber bands are one of the most convenient products of the twentieth century, used by numerous individuals and industries for a wide variety of purposes. The largest consumer of rubber bands in the world is the U.S. Post Office, which orders millions of pounds a year to use in sorting and delivering piles of mail. The newspaper industry also uses massive quantities of rubber bands to keep individual newspapers rolled or folded together before home delivery. Yet another large consumer is the agricultural products industry. The flower industry buys rubber bands to hold together bouquets or uses delicate bands around the petals of flowers (especially tulips) to keep them from opening in transit. Vegetables such as celery are frequently bunched together with rubber bands, and the plastic coverings over berries, broccoli, and cauliflower are often secured with rubber bands. All in all, more than 30 million pounds of rubber bands are sold in the United States alone each year.
Rubber, which derives from plants that grow best in an equatorial climate, was first discovered by European explorers in the Americas, where Christopher Columbus encountered Mayan indians using water-proof shoes and bottles made from the substance. Intrigued, he carried several Mayan rubber items on his return voyage to Europe. Over the next several hundred years, other European explorers followed suit. The word rubber was born in 1770, when an English chemist named Joseph Priestley discovered that hardened pieces of rubber would rub out pencil marks. By the late eighteenth century, European scientists had discovered that dissolving rubber in turpentine produced a liquid that could be used to waterproof cloth.
However, until the beginning of the 19th century, natural rubber presented several technical challenges. While it clearly had the potential for useful development, no one was able to get it to the point where it could be used commercially. Rubber rapidly became dry and brittle during cold European winters. Worse, it became soft and sticky when warn.
The American inventor Charles Goodyear had been experimenting with methods to refine natural rubber for nearly a decade before an accident enabled him to overcome these problems with unprocessed rubber. One day in 1839, Goodyear accidentally left a piece of raw rubber on top of a warm stove, along with some sulfur and lead. On discovering his "mistake," Goodyear delightedly realized that the rubber had acquired a much more usable consistency and texture. Over the next five years, he perfected the process of converting natural rubber into a usable commodity. This process, which Goodyear dubbed vulcanization after the Roman god of fire, enabled the modern rubber industry to develop.
The first rubber band was developed in 1843, when an Englishman named Thomas Hancock sliced up a rubber bottle made by some New World Indians. Although these first rubber bands were adapted as garters and waistbands, their usefulness was limited because they were unvulcanized. Hancock himself never vulcanized his invention, but he did advance the rubber industry by developing the masticator machine, a forerunner of the modern rubber milling machine used to manufacture rubber bands as well as other rubber products. In 1845, Hancock's countryman Thomas Perry patented the rubber band and opened the first rubber-band factory. With the combined contributions of
In the late nineteenth century, British rubber manufacturers began to foster the development of rubber plantations in British colonies like Malaya and Ceylon. Rubber plantations thrived in the warm climate of Southeast Asia, and the European rubber industry thrived as well, because now it could avoid the expense of importing rubber from the Americas, which lay beyond Britain's political and economic control.
Although 75 percent of today's rubber products are made from the synthetic rubber perfected during World War II, rubber bands are still made from organic rubber because it offers superior elasticity. Natural rubber comes from latex, a milky fluid composed primarily of water with a smaller amount of rubber and trace amounts of resin, protein, sugar, and mineral matter. Most non-synthetic industrial latex derives from the rubber tree (Hevea brasiliensis), but various equatorial trees, shrubs, and vines also produce the substance.
Within the rubber tree, latex is found between the external bark and the Cambium layer, through which the tree's sap flows. Distinct from the sap, latex serves as a protective agent, seeping out of and sealing over wounds in the tree's bark. To "tap" the substance, rubber harvesters cut a "V"-shaped wedge in the bark. They have to be careful to make their cuts at a depth of between .25 and .5 inch (.635 and 1.2 centimeters) in a mature tree (7 to 10 inches or 17.7 to 25.4 centimeters in diameter), because they must reach the latex without cutting into the sap vessels. They must also take care to tap each tree in a slightly different place every time. At the end of the nineteenth century botanist Henry Ridley began recommending this measure, having noted that repeated tapping in the same
Sample rubber bands from each batch are subjected to a variety of quality tests. One such test measures modulus, or how hard a band snaps back: a tight band should snap back forcefully when pulled, while a band made to secure fragile objects should snap back more gently. Another test, for elongation, determines how far a band will stretch, which depends upon the percentage of rubber in a band: the more rubber, the further it should stretch. A third trait commonly tested is break strength, or whether a rubber band is strong enough to withstand normal strain. If 90 percent of the sample bands in a batch pass a particular test, the batch moves on to the next test; if 90 percent pass all of the tests, the batch is considered market-ready.
Rubber bands are a "mature product," for which the market is not growing as quickly as it did several years ago. Nevertheless, the demand for rubber bands is steady, and not at all likely to fall off dramatically in the predictable future.
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Graham, Frank and Ada Graham. The Big Stretch: The Complete Book of the Amazing "Rubber Band. Knopf, 1985.
McCafferty, Danielle. How Simple Things Are Made. Subsistence Press, 1977.
Wulffson, Don. L. Extraordinary Stories Behind the Invention of Ordinary Things. Lothrop, Lee & Shepard Books, 1981.
— Lawrence H. Berlow