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锘? Leather ball used in the football tournament at the 1936 Summer Olympics. In 1863 the first specification for footballs were laid down by The Football Association Duncan Keith Womens Jersey , previous to this footballs were made out of inflated leather, with later leather coverings to help footballs maintain their shapes . In 1872 the specifications were revised, and these rules have been left essentially unchanged as defined by the International Football Association Board (for more information see Football (ball)). Differences in footballs created since this rule came into effect has been to do with the material used in their creation. Footballs have gone through a dramatic change over time. During medieval times balls were normally made from an outer shell of leather filled with cork shavings. Another method of creating a ball was using animal bladders for the inside of the ball making it inflatable. However, these two styles of creating footballs made it easy for the ball to puncture and were inadequate for kicking. It was not until the 19th century that footballs developed into what we believe a football looks like today. In 1838, Charles Goodyear introduced the use of rubber and his discoveries of Vulcanization, which dramatically improved the football. Vulcanization is the treatment of rubber to give it certain qualities, for example strength, elasticity Blackhawks Patrick Kane Jersey , and resistance to solvents. Vulcanization of rubber also helps the football resist moderate heat and cold. "The chemical process involves the formation of cross-linkages between the polymer chains of the rubber molecules." Vulcanization helped create inflatable bladders that pressurize the outer panel arrangement of the football. Charles Goodyear's innovation increased the bounce ability of the ball and made it easier to kick. Most of the balls of this time had tanned leather with eighteen sections stitched together. These were arranged in six panels of three strips each. During the 1900s footballs were made out of rubber and leather which was perfect for bouncing and kicking the ball, however when heading, hitting the ball with the player's head, the football it was usually painful. This problem was most likely because of the water absorption of the leather if it rained during the game, causing head injury. Another problem that the early footballs had was that they deteriorated too soon. Because of the leather quality the footballs varied in thickness and in quality sometimes worsening during the soccer match. Adidas Teamgeist ball used at the 2006 FIFA World Cup. Elements of the football that today are tested are the deformation of the football when it is kicked or when the ball hits a surface. Two styles of footballs have been tested by the Sports Technology Research Group of Wolfson School of Mechanical and Manufacturing Engineering in Loughborough University; these two models are called the Basic FE model and the Developed FE model of the football. The basic model considered the ball as being a spherical shell with isotropic material properties. The developed model also utilized isotropic material properties but included an additional stiffer stitching seam region. The result was that the Developed FE model resisted deformation more than the Basic FE model ensuring that the football will continue to develop even in the present, thanks to David Beckham who contributed to this project of the gravity controlling soccerball. He is to receive a near 1 billion US$ if the project is successful. Companies such as Mitre, Adidas, Nike and Puma are releasing footballs made out of new materials which promise more accurate flight and more power to be transferred to the football. Today footballs are a little more complex than past footballs. Modern footballs consist of twelve regular pentagonal and twenty regular hexagons Blackhawks Marian Hossa Jersey , positioned in a condensed icosahedrons spherical geometry. The inside of the football is made up of a latex bladder which enables the football to be pressurized. The ball panel pairs are stitched along the edge; this procedure can either be stitched manually or with a machine. Many companies throughout the world produce footballs. However Adidas has supplied match balls for all official FIFA and UEFA matches since the 1970s, and also supplied match balls for the 2008 Olympic Games . They also supply the ball for the UEFA Champions League which is called the Adidas Finale. The following footballs were used in the FIFA World Cup finals over the years : The first ball with a black and white pattern used in the FIFA World Cup finals. First fully synthetic FIFA World Cup ball and first hand-sewed ball First multi-coloured ball at a World Cup finals tournament The +Teamgeist is a 14 panel ball. Each match at the World Cup finals had its own individual ball, printed with the date of the match, the stadium and the team names. It was replaced for the final match by the gold-coloured +Teamgeist Berlin. This balls has 8 panels. The following balls were used in the UEFA European Football Championship over the years: This was the same ball used as in the 1990 FIFA World Cup. football World - Early History (Accessed June 9, 2006) a b Price, D. S., Jones, R.Harland Blackhawks Corey Crawford Jersey , A. R. 2006. Computational modeling of manually stitched footballs. Proceedings of the Institution of Mechanical Engineers -- Part L Journal of Materials: Design & Applications. Vol. 220 Issue 4, p259-268. a b Materials Science and Engineering: A Volume 420, Issues 1-2, 25 March 2006, Pages 100-108 The History of the football. www.soccerballworldHistorypg2.htm. Date retrieved: October 12, 2008 a b Viscoelasticity of multi-layer textile reinforced polymer composites used in footballs. Journal of Materials Science. Volume 43, Number 8 April, 2008. 2833-2843. football World - 2000 and Beyond (Accessed June 9 Blackhawks Jonathan Toews Jersey , 2006) a b football World - Team Geist (Accessed June 9, 2006) The Guardian, June 5, 2006, World Int.