Facts About Glass - Types, Properties and Uses
Glas is neither a liquid nor a solid. It is a transparent amorphous solid that is made from sand. You can see different forms of glass in windows, bulbs, lenses, drinking glasses, storage bottles, mirrors, laboratory and medical equipment.
Glass is easy to manufacture and shape. It is chemically inert and resistant to heat. It is an eco-friendly material that can be recycled many times without losing its original properties.
What is glass?
Gass is neither a liquid nor a solid. It falls in the range between a liquid and a solid. A solid has a highly organized structure, but liquids and glass do not have the rigid structure that a solid has.
During the manufacturing process, the molten mixture containing silica is quickly cooled below its melting point to become a supercooled liquid (a supercooled liquid is an intermediate stage between the state of a liquid and a gas.)
When the supercooled liquid is cooled further, it becomes an amorphous solid that has a structure that is not as rigid as a solid but it has a structure that is more organized than a liquid.
How is glass made?
Glass is manufactured by heating recycled glass, sodium carbonate (soda ash) and calcium carbonate (limestone) in a furnace. This glass is also known as soda-lime-silica glass.
The soda-lime-silica glass is melted and poured into molds to make bottles, glasses, jars. To make flat glass sheets for windows, the molten glass is poured into a big tank that has molten tin metal.
A ball of molten glass is wrapped around an open pipe and then slowly rotated. Hot air is blown through the pipe, and the molten glass ball blows up like a balloon and is skilfully manipulated to produce decorative glass containers. Glass makers add chemicals to the glass to make decorative objects colorful.
Properties of Glass
The properties of glass depend upon the substances that are added while manufacturing the glass. The substances that are added to alter the properties of glass are mostly in the form of oxides.
- Lead is added to enhance the brilliance and weight of glass
- Boron for thermal and electrical resistance
- Barium to increase the refractive index
- Cerium to absorb infrared rays
- Metallic oxides to give color
It is an excellent material for making household items such as glass, plates, storage bottles because glass is chemically inert and does not react with the eatables stored in glass jars.
Types of Glass & Uses
Laminated Glass is made by fusing alternate layers of flat glass and plastic. When laminated glass breaks due to heavy impact, the glass that receives the impact breaks but the plastic layer on the inside hold the glass pieces together and prevent them from flying in all directions.
This type of glass is used in making automobile windshields. If the windshield breaks due to an accident, the laminated glass will prevent the glass pieces from flying inside the vehicle and prevent the passengers from injury.
Fiberglass is made of fine, solid rods of glass, each one of these rods measures to about less than one-twentieth of the width of a human hair.
It is used to make wool-like fibers that serve as heat insulation material. This glass can also be used like wool or cotton fibers to make glass yarn, tape, cloth, and mats. It is also used for electrical insulation, chemical filtration and to make firefighter suits.
Fiberglass is combined with plastic and used in the manufacture of airplane wings, body parts of automobiles and boat hulls.
Bulletproof Glass is a thick multilayer of laminated glass that can stop heavy-caliber bullets. It shatters on impact, but the plastic layers of this glass hold the glass fragments together. This type of glass is also used in the manufacture of bank teller windows and to make windshields for military tanks and aircraft.
Tempered Glass is stronger than laminated glass. It is a single sheet of glass and does not have several layers similar to the laminated glass. It is used for glass doors, side and rear windows of automobiles, and basketball backboards. This glass is hard to break but when it does it shatters into many fragments.
Foam Glass is filled with many tiny cells of gas. Each cell is sealed off from the other by a thin glass wall. It is light and floats on water. It is used as an insulator in buildings, steam pipes and in chemical equipment.
Heat Resistant glass is high in silica and contains boric acid. This glass expands slightly when heated and does not crack at high temperatures. Due to the heat-resistant property, this type of glass is used in the manufacture of cookware, household, laboratory and industrial equipment. It is also used in the manufacture of electric bulbs and television sets.
Heat Reflective Glass has two panes of glass separated by a layer of argon gas that helps to improve insulation. This type of glass is used to make windows of apartments and other buildings. It helps to keep your home warm during winter and cool during summer and helps to reduce the electricity bill.
Other Types of Glass
Glass Optical Fibers are used to transmit information in the form of pulses of light. These fibers are extremely thin and are used to transmit telephone, television signals and digital data over long distances.
Glass Ceramics can withstand very high temperatures and can take a sudden change in temperatures without breaking and is resistant to chemical erosion. This type of glass is used in cookware, turbine engines, electronic equipment and nose cones of guided missiles.
Stained Glass is made by adding chemical compounds to the molten glass. Each compound gives a different color to the glass depending upon the chemical nature. It is used to make beautiful windows and other decorative objects.
Crystal Glass is a fine quality glass. It is made from silica, lead oxide, soda, or potash. It is used to make wine glasses and other decorative ornaments.
Why glass is an eco-friendly material?
Glass is an eco-friendly material because -
- Glass can be recycled many times without the loss of its original properties.
- Manufacture of new glass from glass that has been recycled will need less energy when compared to new glass made using raw materials.
- Recycling glass reduces the amount of carbon dioxide released into the atmosphere.
Glass Formed Due to Forces of Nature
When the soil is rich in silica and the conditions are ideal, forces of nature create glass.
- Fulgurite Glass forms when cloud to ground lightning occurs
- Obsidian Glass is a result of the volcanic activity
- Meteoritic Glass or Tektite glass forms due to the collision of a meteorite with the surface of the earth
In 1945, the first nuclear bomb that was equivalent to 18,000 tons of TNT was detonated in the New Mexico desert. The explosion resulted in a crater that was 800 yards in diameter, glazed with dull-grey silica glass.
Glass is an eco-friendly material that can be recycled and reused many times. It is chemically inert and can be safely used to manufacture cookware and dinnerware. It is versatile, and the properties of glass can be manipulated to manufacture products across many applications.
© 2017 Nithya Venkat