Díaz, Alexandra #09-10230Mata, Elizabeth #09-10513

Glass

1.Glass (Advantages and disadvantages)

2. The glass through the history:• Glass in the antiquity• Glass in the middle ages• Glass in the renaissance till the

eighteenth century3. Types  of glass4. Glass production5. Glass utility

Glass is a hard, non-crystalline and solid material normally fragile and transparent common in our daily life.

Glass

Kosta window

Properties and characteristics◦ Solid and hard

material◦ Fragile and easily

breakable◦ Transparent to

visible light◦ Inert and biologically

inactive material◦ 100% recyclable

Glass

The first objects made of glass were beads, and necklaces. The theory was that Asian artisans established the manufacture of glass in Egypt . the production of glass flourished in Egypt and Mesopotamia in 1200 B.C. and later almost ceased completely, during several centuries. In the first one mentioned (Egypt)

the glass was clear, coloring of blue and green. 

Glass in the antiquity

the most important production in this material during the Middle Ages were the glass mosaics in the Mediterranean Europe and the windows in the north.The art of glass manufacturing declined at the end of the Renaissance but recovered again in the nineteenth century. 

Glass in the middle age

Although the glass was already been made in Venice since the tenth century. The most important contribution was the development of Venetian glass hard.

All the European glass manufacturers, attempted to copy the techniques, material and furnishings.

The Italian influence declined in the seventeenth century, the emergence in Germany and England, new methods for the

manufacture of glass.

renaissance till the eighteenth century

Commercial glass Lead glass Borosilicate glass Recently develops

◦ Safety glass◦ Fiberglass◦ Foam

Types of glass

There are three ways of making glass and they are:

1. Sand (SiO2 silica)In its pure form it exists as a polymer, (SiO2)n. 

2. Soda ash (sodium carbonate Na2CO3)Normally SiO2 softens up to 2000°C, where it starts to degrade (at 1713°C most of the molecules can already move freely). Adding soda will lower the melting point to 1000°C making it more manageable.

3. Limestone (calcium carbonate or CaCo3) or dolomite (MgCO3)Also known as lime, calcium carbonate is found naturally as limestone, marble, or chalk.The soda makes the glass water-soluble, soft and not very durable. Therefore lime is added increasing the hardness and chemical durability and providing insolubility of the materials.

Glass production

http://www.lenntech.com/Glass.htm http://lie.asignaturas.usb.ve/file.php/93/

glass.pdf http://www.wikipedia.org/

References