Glass By: Mario Popoli Augusto González

DefinitionPropertiesAdvantagesDisadvantagesHistoryUses Uses in architecture

So… you thought glass was boring right? was boring right?

Definition

Glass is a hard, brittle substance made by fusing silicates with soda or potash, lime, and, sometimes, various metallic oxides into a molten mass that is cooled rapidly to prevent crystallization or annealed to eliminate stresses: various types of glass can be transparent, translucent, heat- resistant, flexible, shatterproof, photochromic, etc. Glass generally refers to a hard, brittle, transparent amorphous solid, such as that used for windows, many bottles, eyewear, and so on.

Origin

Before man learned the secret of glassmaking, nature was the world's only glassmaker. Lightning striking sand melted it into long, thin tubes of glass, and volcanoes erupting melted rocks and sand into glass.

Today, three inexpensive ingredients, sand, soda ash, and lime, are melted together to make glass. This is done in large furnaces at high temperatures until the mixture become a syrupy mass. When this syrup cools, it is glass.

Methods

When glass is in a melted state, it can be shaped by many methods, but the most common are blowing, pressing, and drawing.

Blowing

Blowing is the oldest method of working with glass, dating back thousands of years. A ball of molten, or melted, glass is put on the end of a hollow iron pipe, and a worker blows gentle into the pipe (much like the way you blow soap bubbles) until the glass takes the shape and thinness the blower wants. During this process, the glass is constantly reheated to keep it soft and workable. When the glass is shaped to the blower's satisfaction into a bottle or a vase, it is broken from the pipe. Although glass blowing by hand is still done today, it can also be done by machine.

Pressing

In the pressing method, a hot glob of glass is dropped into a mold, then pressed with a tool, so the glass fills the inside of the mold. Ashrays, baking dishes, and glass containers are made this way.

Drawing

The drawing method shapes glass flat, as for windows and mirrors, or into tubes, as for fluorescent lights, TV tubes, and laboratory equipment. To make flat glass, first the melted glass is drawn into a tank of melted tin. The tin's perfectly smooth surface forms a smooth layer of glass as the glass floats on top of the tin. To make glass tubing, a stream of molten glass is drawn around the inside of a cylinder. As the cylinder rotates, air is blown through it, forming a continuous tube out of the glass.

No matter which method is used, the glass must still go through a process called annealing. In annealing, the glass is reheated. Tempering is also used to strengthen glass. In tempering, the glass is reheated, then chilled by sudden blasts of cold air. Banks, tanks, aircraft, and some government cars have glass so thick and with so many layers that it can stop a bullet even at close range!

Lamp working

This process should not be confused with another method called lamp working, in which finished glass tubes are heated over a blowtorch, and as the glass worker bends, twists, and stretches the glass, he can create miniature animals, ships, and baskets.

Properties

The properties of glass are varied by adding other substances, commonly in the form of oxides: lead, for brilliance and weight; boron, for thermal and electrical resistance; barium, to increase the refractive index, as in optical glass; cerium, to absorb infrared rays; metallic oxides, to impart color; and manganese, for decolorizing.

Advantages

Advantages Excellent abrasion resistance Resistant to chemicals, solvents, oil, grease No problem with UV degradation Stable over a wide range of temperature Easily cleaned Long life product Looks good Transparency Price

Disadvantages

Disadvantages Delicate and heavy Doesn’t work as a structural material Not very robust Shatters easily when stressed, Solar heat penetrates it Transparency Price

History

History 5000BC 5000BC Egypt - Merchants Egypt - Merchants 1600BC 1600BC Mesopotamia - Glass Making Mesopotamia - Glass Making 27BC 27BC Syria – Glass Blowing Syria – Glass Blowing 100AD 100AD Romans – Clear Glass (adding) Romans – Clear Glass (adding) Pompei Pompei

History 11th & 12th Centuries 11th & 12th Centuries Germany – Glass sheets Germany – Glass sheets 17th Century 17th Century British - Reflects better (adding) British - Reflects better (adding) French – Mirrors (Polishing) French – Mirrors (Polishing) 20th Century 20th Century Squeezing glass – Double glazing Squeezing glass – Double glazing

Types

Types Oridinary sheet glass Oridinary sheet glass No special equipment No special equipment Cheaper Cheaper Float glass (plate) Float glass (plate) Molten glass is floated onto a bed of molten tin Molten glass is floated onto a bed of molten tin Energy efficient glass Energy efficient glass Sun to pass through in one direction. Sun to pass through in one direction. Covering is not very robust – double glazed Covering is not very robust – double glazed Self cleaning glass Self cleaning glass New treatment New treatment Patterned (obscured glass) Patterned (obscured glass) Special designs Special designs

Types Toughened (Safety glass) Toughened (Safety glass) Explode - Small Pieces Explode - Small Pieces Laminated glass Laminated glass 1 or two sheets 1 or two sheets Flexible material inside (Break) Flexible material inside (Break) Any shapes Any shapes Mirrors Mirrors 6mm thick 6mm thick Silvered Silvered Unframed Unframed Picture frame glass Picture frame glass High transparency High transparency Low reflective properties Low reflective properties

Uses

Glass is the transparent solid that we see around us on a regular basis. With time, glass has come to be used in various forms. This brittle object is used on a large scale and has gained certain importance. As light is visible due to the absence of transition states, the glass appears to be transparent. In the initial years, glass hardly had any use, today it used for bottles, bulbs, dining sets, mirrors and also to decorate your homes.

The spectacles that you wear are also made of glass. When you walk through a laboratory you will find all the containers made out of glass. This is because it helps a person to check certain levels of chemicals and so on. Your eyewear also has the glass shaped in rectangular or oval shape. Glass also makes a fantastic tabletop and you can use it as a center or coffee table. Glass can be manufactured in any shape and can be put in any possible use.

Glass can come in thin or thick sizes. Depending upon the use, one can choose the right shape and size. To add a stylish look to your home, you can use glass dining table. To make the most of your dining table, you can set your eyes on some well-crafted glass dining sets. Today even mirrors are popularly used for decorating homes. Mirrors are made of glass it self. Car and home windowpanes are also made out of glass. Today, walk into any corporate office and you would find the entire building made out of glass. For buildings, strong and durable glass is used. These offices normally use soundproof glass to ensure safety and a peaceful atmosphere at work.

Glass is used in combination with wood to create furniture. Most tabletops and cabinets have this combination. The glass is resistant to high and low temperatures, which gives it a longer life. Glass can be used to come up with artistic work as well. You can mould it into tiny animals or abstracts and decorate your home. The chandeliers that enhance the look of your home are also made of glass.

Always look out for a well-known manufacturer to purchase quality and durable glass. Cheap glass will not last long, making it difficult to replace the windowpanes ever so often. To make unique use of glass, you can opt for customized ones that look simply astonishing. Again you need to get in touch with a good dealer who can offer you the best. When purchasing glass, make sure you go for those that are easy to maintain and taken care of.

Uses in Architecture

External Decoration External Decoration Saves energy (bad conductor of heat) Saves energy (bad conductor of heat) Lighting Lighting Sense of openness Sense of openness Views Views Beauty Beauty