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Four metals are commonly used for the packaging of foods: steel, aluminum, tin and chromium. Tin and steel, and chromium and steel, are used as composite materials in the form of tinplate and electrolytically chromium-coated steel (ECCS), the latter being somewhat unhelpfully referred to as tin-free steel (TFS). Aluminum is used in the form of purified alloys containing small and carefully controlled amounts of magnesium and manganese. Two other metals are used during the soldering or welding of three-piece tinplate and ECCS containers: lead and copper. However, because they are not used for the fabrication of containers in their own right, they are not discussed in detail in this chapter. The safety aspects of these different metals, together with can coatings.
The first commercial manufacture of tinplate occurred in England in 1699 and in France in 1720, where it was used for a variety of purposes including household utensils such as plates. Some time in about the middle of the eighteenth century, the Dutch navy began to use foods preserved by packing them in fat in tinned iron canisters. 13 After cooking and while still hot, the material to be preserved was placed into the canister, covered with hot fat and the lid immediately soldered on. Records show that from 1772 to 1777, the Dutch government supplied their navy (which had been sent out to Suriname [formerly Dutch Guiana in South America] to quell a revolt) with roast beef packed in this way.
Before the end of the eighteenth century, the Dutch had also established a small industry to preserve salmon in a similar manner. Freshly caught salmon were cleaned, cooked in boiling brine, smoked over a wood fire for 2 days and then placed in a tinplated iron box. The spaces were filled up with hot salted butter of olive oil and a lid was soldered onto the box.13 A famous London firm of snuff merchants supplied 13 tins of Dutch salmon to one of their clients in 1797.4 Thus, a canning industry of sorts had been established in Holland independently of, and prior to, Appert’s work.
The French confectioner Nicolas Appert discovered a method of “conserving all kinds of food substances in containers,” and, in 1804, produced preserved meat for the French navy by packing it in glass champagne bottles, sealing them with a cork held in place with wire, and heating in boiling water for several hours. Appert received an ex gratia payment of 12,000 francs in 1810 from the Ministry of the Interior’s Bureau of Arts and Manufactures on the condition that he publish details of this process; Appert obliged and 200 copies of his book were printed the same year. Appert deliberately avoided tinplate in his early work because of the poor quality of the French product, according to the fourth (1831) and fifth (1858) editions of his book. However, the quality of tinplate in England was good and it was freely available.
After almost two centuries of history, there is still controversy as to who introduced the in can as a package. The latest account, based on extensive research of early nineteenth century archives,3 has thrown, additional light on those involved in the genesis of the canning industry and has revealed a new name: the French inventor Phillipe de Girard. It appears that he got Durand (a broker in London) to patent the process in 1810, the patent referring to the substitution of glass jars and bottles with tin cases. A successful trial with the Royal Navy was undertaken at Durand’s request in 1811, and the patent was acquired by Bryan Donkin in 1812 for which Girard received L1000. Donkin had become interested in the tinning of iron as early as 1808 and, as mentioned in Chapter 6, was involved with John Gamble in developing the Fourdrinier papermaking machine.
Donkin applied to the British Admiralty for a test of his product and the first substantial orders were placed in 1814 with the London firm of Donkin, Hall and Gamble for meat preserved in tinplate canisters (John Hall was the founder of the famous Dartford Iron Works). By the 1820s, canned foods were a recognized article of commerce in Britain and France.
To complete the historical record, William Underwood left London and arrived in New Orleans in 1817. He traveled up to Boston where he started a business preserving food in glass jars by Appert’s method. In 1819, Thomas Kennsett, also from England, started a similar business in preserved foods in New York in partnership with his father-in-law Ezra Daggett. The first offering of preserved provisions in tin cans in America is assumed to be the announcement by Daggett and Kensett in the New York Evening Post of July 18, 1822,1 although it was not until 1825 that they took out a patent in which “vessels of tin” were mentioned.
The American Civil War provided the opportunity for canning to become a great industry, and by the end of the war in 1865, canners had increased their output sixfold. For many years, the cans were made slowly and laboriously by hand. Both ends were soldered to the can with a hole of about 25 mm in diameter left in the top. After the can was filled through this hole, a metal disc was soldered into place. The mechanical roll crimping (commonly known as double seaming) of the can ends onto a body with a soldered sideseam was patented in 1896 by Max Ams of New York,13 making it possible to develop high-speed equipment for the making, filling and closing of these cans. In 1892, the first pineapple cannery was established in Hawaii. The first canned soup was produced in the U.S. in 1897.
Today, materials like tinplate and aluminum have become universally adopted for the manufacture of containers and closures for foods and beverages, largely due to several important qualities of these metals. These include their mechanical strength and resistance to working, low toxicity, superior barrier properties to gases, moisture and light, ability to withstand wide extremes of temperature and ideal surfaces for decoration and lacquering.
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