Float glass is made by melting raw materials consisting of sand, limestone, soda ash, dolomite, iron oxide and salt cake at a temperature of 2800 degrees. The raw materials are mixed together and fed into a large furnace that is natural gas or fuel oil fired. The raw materials, referred to as batch, blend together to form a large pool of molten glass. The molten glass at 2000 degrees is fed into the float bath (tin bath) through a delivery canal. The amount of glass allowed to pour onto the molten tin is controlled by a refractory gate called a tweel. The tin bath is provided with a protective atmosphere consisting of a mixture of nitrogen and hydrogen to prevent oxidation of the tin. The glass flows out onto the tin surface forming a floating ribbon with perfectly smooth glossy surface on both sides with an even thickness from .082" to .5". Thinner glass is made by stretching the glass ribbon to achieve the proper thickness. Thicker glass is made by not allowing the glass to pool. Machines called attenuators are used in the tin bath to control both the thickness and the width of the glass ribbon. As the glass flows down the tin bath, the temperature is gradually reduced to around 1100 degrees until the sheet can be lifted from the tin onto rollers. It then passes through the lehr where it is further cooled gradually so that it anneals without strain and does not crack from the change in temperature. The glass travels down the rollers in the lehr for about 100 yards and comes out at the "cold end" where it is cut by a cross cutter or rabbit and then loaded onto cart or racks with stackers and robots.
50th Anniversary Pictures - June 2012
How we use to make glass.
The Libbey–Owens–Ford Company (LOF) was a producer of flat glass for the automotive and building products industries both for original equipment manufacturers and for replacement use. The company's headquarters and main factories were located in Toledo, Ohio, with large float glass plants in Rossford, Ohio, Laurinburg, North Carolina, Ottawa, Illinois, and Lathrop,California. The company was formed by the merger of Libbey-Owens' flat-glass operation with the Edward Ford Plate Glass Company, both located in Toledo, in 1930.In the spring of 1916, Michael Owens and Edward Drummond Libbey, both manufacturers of sheet glass, merged their respective companies to form Libbey-Owens. In June 1916, the new Libbey-Owens bought Graham Glass along with the Graham brothers' patents for their glass bottle-making machine, allowing them to diversify into consumer products. In 1928, LOF (then Libbey Owens) was the first company to produce automotive laminated safety glass and won a contract to supply the Ford Motor Company with windshields for the Model A. Libbey-Owens mergered with the Edward Ford Plate Glass Company in 1930 to form Libbey–Owens–Ford.In April 1986, LOF sold its glass business and name to the Pilkington Group, a multinational glass manufacturer headquartered in the United Kingdom. The remaining three business units of the company, Aeroquip, Vickers, and Sterling, were retained and the holding company was renamed TRINOVA Corporation. The Sterling business was later sold and in the late 1990s, the company adopted its two leading business unit names, and continued as Aeroquip-Vickers, Inc., until being absorbed by Eaton Corporation in 1999.As part of the Pilkington Group, the company retained the LOF name. However, in June 2006, Pilkington was acquired by Nippon Sheet Glass, and the LOF name was abandoned in an effort to rebrand globally under the Pilkington name.