Tomsk Polytechnic University

Automatic and robotic

building department

Glass

Project work

Made by Tkachenko D.

to Khrulyova O.S.

Tomsk 2007

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Contents

• Introduction_______________________________2

• 1 Properties and uses _______________________4

• 2 History of glass ___________________________5

  • 2.1 Phoenicia and Egypt _________________5

  • 2.2 Romans ____________________________6

  • 2.3 Medieval Europe ____________________7

  • 2.4 Industrial revolution glassmaking______8

Introduction

Glass

Glass is a noncrystalline material that can maintain indefinitely, if left undisturbed, its overall form and amorphous microstructure at a temperature below its glass transition temperature. Glass synthesis is achieved by quenching a glass-forming liquid through its glass transition temperature sufficiently fast to avoid the formation of a regular crystal lattice, producing an amorphous solid. Amorphous solids may also be formed by methods other than melt quenching, such as vapour deposition or the sol-gel method. Silica glass may be produced by using sand as a raw material (or "quartz sand") that contains almost 100 % crystalline silica in the form of quartz. Glass is sometimes created naturally from volcanic magma. This glass is called obsidian, and is usually black with impurities. Obsidian is a raw material for flintknappers, who have used it to make extremely sharp knives since the stone age. The known manufacture of glass dates back to 3000 BC and glass technology is widely used in the modern day in household objects such as bottles, mirrors, windows and light bulbs. The most common method for glass pane production is using molten tin, where the molten glass floats on top of the perfectly flat molten tin, thus giving it the name "float glass". The refractive, reflective and transmission properties of glass make specific chemical compostitions suitable for technological applications such as optics and optoelectronics. The manipulation of heated glass enables it to be shaped into different forms and the incorporation of additives at the manufacturing stage produces different colors which enable glass to be used as an art medium for display purposes.

Properties and uses

A vase being created at the Reijmyre glassworks, Sweden

The most obvious characteristic of ordinary glass is that it is transparent to visible light, hence its wide application in everyday use. This transparency is due to an absence of electronic transition states in the range of visible light. The homogeneity of the glass on length scales greater than the wavelength of visible light also contributes to its transparency as heterogeneities cause light to be scattered, breaking up any coherent image transmission. Many household objects are made of glass. Drinking glasses, bowls, and bottles are often made of glass, as are light bulbs, mirrors, cathode ray tubes, and windows. In scientific research laboratories, flasks, test tubes, lenses and other laboratory equipment are often made of glass. For these applications, borosilicate glass (such as Pyrex) is usually used for its strength and low coefficient of thermal expansion, which gives greater resistance to thermal shock and allows for greater accuracy in laboratory measurements when heating and cooling experiments. For the most demanding applications, quartz glass is used, although it is very difficult to work. Most such glass is mass-produced using various industrial processes, but most large laboratories need so much custom glassware that they keep a glassblower on staff. Volcanic glasses, such as obsidian, have long been used to make stone tools, and flint knapping techniques can easily be adapted to mass-produced glass.

History of glass

Phoenicia and Egypt

Naturally occurring glass, such as obsidian, has been used since the stone age. According to Pliny the Elder, the Phoenicians made the first glass:

The tradition is that a merchant ship laden with nitrum being moored at this place, the merchants were preparing their meal on the beach, and not having stones to prop up their pots, they used lumps of nitrum from the ship, which fused and mixed with the sands of the shore, and there flowed streams of a new translucent liquid, and thus was the origin of glass.

Glass used as a glaze for pottery is known as early as 3000 BC. However, there is archaeological evidence to support the claim that the first glass was made in Mesopotamia. ^[21] Glass beads, seals, and architectural decorations date from around 2500 BC. Glass was also discovered by Native Americans during the same time period.

Core-formed amphoriskos (17 cm / 6.7 in tall) 1st century BC, Cyprus

Romans

Roman Cage Cup from the 4th Century A.D.

Roman Glass

During the Roman Empire craftsmen working as non-citizens developed many new techniques for the creation of glass. Through conquest and trade, the use of glass objects and the techniques used for producing them were spread as far as Scandinavia, the British Isles and China.^[23] This spreading of technology resulted in glass artists congregating in areas such as Alexandria in Egypt where the famous Portland Vase was created, the Rhine Valley where Bohemian glass was developed and to Byzantium where glass designs became very ornate and where processes such as enamelling, staining and gilding were developed. At this time many glass objects, such as seals, windows, pipes, and vases were manufactured. Window glass was commonly used during the 1st century BC

Medieval Europe

Glass objects from the 7th and 8th centuries have been found on the island of Torcello near Venice. These form an important link between Roman times and the later importance of that city in the production of the material. Around 1000 AD, an important technical breakthrough was made in Northern Europe when soda glass, produced from white pebbles and burnt vegetation was replaced by glass made from a much more readily available material: potash obtained from wood ashes. From this point on, northern glass differed significantly from that made in the Mediterranean area, where soda remained in common use.

A 16th Century Stained Glass Window

The 11th century saw the emergence in Germany of new ways of making sheet glass by blowing spheres. The spheres were swung out to form cylinders and then cut while still hot, after which the sheets were flattened. This technique was perfected in 13th century Venice. Until the 12th century, stained glass, glass with metallic and other impurities for coloring, was not widely used.

The Crown glass process was used up to the mid-1800s. In this process, the glassblower would spin approximately 9 pounds (4 kg) of molten glass at the end of a rod until it flattened into a disk approximately 5 feet (1.5 m) in diameter. The disk would then be cut into panes. Venetian glass was highly prized between the 10th and 14th centuries.

Industrial revolution glassmaking

The invention of the glass pressing machine in 1827 allowed the mass production of inexpensive glass products.

The cylinder method of creating flat glass was used in the United States of America for the first time in the 1820s. It was used to commercially produce windows. This and other types of hand-blown sheet glass was replaced in the 20th century by rolled plate glass, and then again in the 1960s by float glass, at first in the UK and then elsewhere.

Glass can be made transparent and flat, or into other shapes and colors as shown in this sphere from the Verrerie of Brehat in Brittany.	Macro detail from a glass bowl blown by artisans at The World of Glass Museum (incorporating the Pilkington Glass Museum), St. Helens, UK. The white effect is created by rolling the molten glass in white glass powder before spinning the glass out to make the bowl.	Glass sculpture by Dale Chihuly at a 2005 exhibition in Kew Gardens, London, England. The piece is 13 feet (4 m) high	Lampworked glass beads and pendants illustrate some of the myriad colors and shapes of glass art.
Swan made of colored glass.

Market structure

The global market for flat glass in 2005 was approximately 41 million tonnes. At the level of primary manufacture this represents a value of around $19 billion.

A decorative glass store in Rome

Literature list:

http://www.glassfacts.info/dfgb445tcvc/sjkgf

http://www.cmog.org/skdhksjns/78d6yfs/

http://www.glassonweb.com/

http://glassproperties.com/

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