The glass manufacturing process as we know it today is sophisticated, highly automated and produces large amounts of glass. The origins of the glass production was quite different. Nature was the first to produce glass when she made Obsidian also known as volcanic glass. Obsidian is a naturally occurring byproduct of volcanic eruptions and has been a prized tool source for prehistoric societies due to its sharp edges and workability. A second natural occurring form of glass are fulgurites, which occurs when lightning strikes in sandy soil. The lighting i.e. electricity going to ground produces heat which melts the sand.
Man first produced a form of glass somewhere between 5000 to 6000 years ago. It is general accepted that first prehistory glass was made about 3500BC in Mesopotamia and Egypt. When heated crushed quartz was used to make glazes for ceramic vessels. It is thought that glass was probably found by accident in association with copper smelting or sand accidentally left in the ceramic kiln.
Production of molded and cast glass vessels dated back to the late Bronze Age in Mesopotamia and Egypt. Mosaic glass, in which slices of colored glass used to produce a decorative pattern was made in Egypt during the Ptolemaic period of Egypt. Blown glass was invented during the 1st Century by glassmakers of Syria.
Lead glass called "cristallo" was first produced during the 15th century in Venice. It was heavily exported at that time. George Ravenscroft invented leaded crystal glass in 1675 by adding lead oxide to Venetian glass.
Window glass dates back to Roman times. During the Middle Ages window glass was made by hand blowing a glass disk that was then spun so centrifugal force would make the glass to thin and flatten. The next improvement in window glass production was know as cylinder glass. In this process, molten glass was free form blown into a cylinder shape that was cut on the long axis and then flattened.
In 1688, a Frenchman named Louis Lucas de Nehou developed a manual process for making plate glass. His process took 16 days from start to finish. The glass he produced was so expensive that only the very rich could afford to purchase it. Over the next two hundred years there were many improvements in power sources needed to melt the raw materials into glass as well as improvements in the glassmaking process itself. However, the French plate glass method remained the basic technique until the 1900s. During the 1900s. improvements in technology made possible large scale glass manufacturing as we now know today.
Irving W. Colburn patented the sheet glass drawing machine on March 25, 1904, making possible mass production of glass for windows. On August 2, 1904, a patent for a "glass shaping machine" was granted to Michael Owen. His invention allowed for high volume production of bottles, jars, and other containers possible. Thus the modern glass industry of today was born.
The preceding paragraphs have been a brief Introduction of the glass making process from antiquity to the early 1900s. We will now turn to Glass Types, in which we will discuss how glass is produced, colored and what manufacturing techniques are used in its production.
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