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GLASS

Glass, existing for millions of years, has fascinated and attracted much interest both scientifically and technologically. For long, glass was considered the “fourth state of matter” before the realization of its “liquid-like” structure. Glass appears on cooling down a liquid continuously until its viscosity becomes so high that it freezes to a glassy state. This happens at some range of temperatures that depends on thermal history. This lets glass be amysterious material, since the way it is prepared may change its properties. These theoretical considerations did not however prevent the development and use of glass over the centuries. Empirical knowledge and know-how have developed through the ages so that, nowadays, glass is a commonly available material. The application of glass science to the improvement of industrial tools, so called Research and Development (R&D). Glass has been employed in many forms to fabricate glazing and containers for centuries while it is now entering new applications that are appearing in nanotechnology (fibres and displays). Many qualities make glass attractive since it is transparent, chemically inert, environmentally friendly and keeps very strong. In fact, no other materials being mass-produced have shown such qualities over so many centuries. Nowadays glass offers recycling opportunities and allows for tailoring new and dedicated applications.The glass industry has been developing considerably in efficiency in terms of production rate and quality over the past few decades. Studying glass history in terms of raw materials and process offers an interesting perspective and understanding of how the glass industry progressively developed. These progresses were achieved because of further knowledge on materials properties and tools. The evolution in technology varies much according to the area of application.