GLASS

1. GLASS Ana María Brito María de Lourdes Rodríguez Isni Parra ID-2125

2. What is Glass? • How make it? • Components of Glass • History of Glass (Origins) • Properties • Recycling • Functions of Glass (uses of Glass) • Glass in construction • Types of Glass

3. Glass, an amorphous substance made primarily of silica, usually produced when the viscous molten material cools very rapidly to below its glass transition temperature, without sufficient time for a regular crystal lattice to form. Glass is found in nature, as the volcanic material obsidian and as the enigmatic objects known as tektites . It is neither a solid nor a liquid but exists in a vitreous, or glassy, state in which molecular units have disordered arrangement but sufficient cohesion to produce mechanical rigidity. Is cooled to a rigid state without the occurrence of crystallization; heat can reconvert glass to a liquid form. Usually transparent, glass can also be translucent or opaque. Color varies with the ingredients of the batch. What is Glass?

4. How make glass? The manipulation of the glass only is possible while is found melted, hot and malleable. The glass is manufactured from a complex mixture of composed vitrificantes, like silica, melting, as the alkalies, and stabilizing, as the lime. These commodities are charged in the oven of keg (of continuous production) through a tolva. The oven is heated with burners of gas or petroleum. The flame should reach a sufficient temperature, and for it the air of combustion is heated in some recuperadores they built with bricks refractarios before arrive at the burners. The oven has two recuperadores whose functions change every twenty minutes: one is heated for contact with the ardent gases while the other provides the heat accumulated al air of combustion. The mixture melts (zone of fusion) to some 1.500 °°c. and advances toward the zone of cooling off, where takes place the recocido. In the other extreme of the oven a temperature from 1.200 to 1800 °c is reached . To the glass thus obtained is given him form by lamination.

5. Components of Glass The basic ingredient of glass compositions is silica, derived from sand, flint, or quartz Common glass contains about 70-72 weight % of silicon dioxide (SiO2). The major raw material is sand (or "quartz sand") that contains almost 100% of crystalline silica in the form of quartz. Although it is almost pure quartz, it may still contain a small amount (< 1%) of iron oxides that would color the glass, so this sand is usually enriched in the factory to reduce the iron oxide. Large natural single crystals of quartz are purer silicon dioxide, and upon crushing are used for high quality specialty glasses. Synthetic amorphous silica (practically 100% pure) is the raw material for the most expensive specialty glasses. Silica can be melted at very high temperatures to form fused silica glass. Because this glass has a high melting point and does not shrink or expand greatly with changing temperatures. Glass is a poor conductor of both heat and electricity. For most glass, silica is combined with other raw materials in various proportions. Other ingredients such as lead and borax give to glass certain physical properties.

6. History All that is required to make glass is a little sand, a little soda, a little lime and a lot of heat. Legend tells us that Roman seaman, preparing to cook their evening meal on a beach, set their pots on top of stones of natron, a soda used in embalming the dead. As the cooking fire heated both these stones and the sand below, a strange liquid began to flow and that was the origin of manmade glass. More accurate history sets the beginning of glass production nearly twenty-five hundred years earlier than that 1st century account in Mesopotamia where potters fused sand and minerals while firing their clay into glass. Nearly a thousand years later one clever Mesopotamian managed to form a glass tube and blow a bubble at the end, creating the first blowpipe and hence the art of glassblowing. Ancient glass vase, with raised designs

7. The first metal blowpipe came into widespread use in the 1st or second century before Christ and glass production soared, particularly in the Roman world, where glass became available to the rich and the poor. The decline of the Roman Empire brought a lull in glass making, but then came the rise of the Islamic world, with it's beautifully colored and delicately shaped glass. Throughout its history the production of glass would ebb and flow with the various kingdoms of the world. The Italian Renaissance saw Venice and Murano become centers of glass making, with kings and queens seeking out those cities' gossamer creations. The British Empire's glass tradition came to the New World with Jamestown's first colonists, half a dozen of whom were glassblowers. old Roman jar

8. Throughout this long history of glassblowing, skilled men endured the tremendous heat to coax beautiful forms from the fire using nothing more than their breath and a few simple tools. They worked hard to polish their skills to uniformity and precision, but even so each creation was as individual as the maker. In the 1820's Bakewell, Page, and Bakewell introduced the first real development in production glassblowing since the blowpipe, a development that would change how glass was used forever. They patented a process of mechanically pressing hot glass. Suddenly the time-consuming handcrafting that all glass had required was no longer necessary and nearly everything around the home began to be made of glass. Murano Glass

9. Artists who wished to work with glass were forced to the commercial factories that made all these utilitarian objects. In 1962 Harvery Littleton reversed this decline of art glass by discovering that some glass could be melted at a low enough temperature to allow the use of small home-studio furnaces. His discovery brought a rebirth of art glass studios, workshops and schools in the United States, a trend that has only accelerated both nationally and internationally. Once again, men and women stand in front of the glaring heat of furnaces and glory holes with a blowpipe in hand and a vision in their heads, ready to bring form to the molten liquid before them with their breath and a few tools, roughly the same tools the Romans used over two thousand years ago.

10. Main properties of Glass These are the main characteristics of glass: • Solid and hard material • Disordered and amorphous structure. • Fragile and easily breakable into sharp pieces. • Transparent to visible light • Inert and biologically inactive material. • Glass is 100% recyclable and one of the safest packaging materials due to its composition and properties.

11. Glass is used for architecture application, illumination, electrical transmission, instruments for scientific research, optical instruments, domestic tools and even textiles. Glass does not deteriorate, corrode, stain or fade and therefore is one of the safest packaging materials.  These properties can be modified and changed by adding other compounds or heat treatment.

12. Glass Recycling • Recycling reduces the demand for raw materials.  There is no shortage of the materials used, but they do have to be quarried from our landscape, so from this point of view, there are environmental advantages to recovering and recycling glass. For every tonne of recycled glass used, 1.2 tonnes of raw materials are preserved. • Recycling reduces the amount of waste glass which needs to be landfilled.  Although glass is inert and is not directly hazardous to the environment, it will remain there indefinitely. • Taking part in recycling the waste we produce makes us think about the effect we are having on our environment and enables us to contribute towards a greater level of sustainability

13. The glass is a totally recyclable material and there is no limit in the quantity of times that can be re-tried. On having recycled it the properties do not get lost and there saves itself a quantity of energy of about 30 % with regard to the new glass. For his suitable recycling the glass is separated and classified according to his type which by the common thing is associated with his color, a general classification is the one that it divides to the glasses in three groups: green, amber or coffee and transparent. The process of recycling after the classification of the glass needs that any foreign material is separated like they are metallic lids (snacks) and you label, then the glass is crushed and bankrupt together with sand, hidróxido of sodium and limy to make new products that will have identical properties with regard to the glass made directly of the natural resources. In some cities of the world programs of glass recycling have been implemented, in them they can find special containers for glass in public places. In certain cases the glass is re-used, before that recycled, that is to say, is not fused, but it returns to use only washing it in case of the containers or cutting it in case of a glassware for giving two examples.

14. Functions of Glass (uses) In food Industry Glass is very hygienic and it no affect the characteristics of others compounds In laboratories Glass is less reagent that others materials.

15. In jewels Rings, neckless, earrings Tutankhamen mask was made with a thick layer of gold and glass

16. In communication To transmit luminous signals produced by laser. Fiber glass Cables of optic fiber

17. Other areas Decoration Stained-glass window Furniture Lamps Sunglasses

18. Glass in constructions Machester Picadilly Louvre Down town Minneapolis

19. Brick of glass, let light enter in the spaces Tunnels Reflection surface Domes

20. Types of Glass Laminated glass Armed glass or wired glass Tempered glass

21. Another photos of used glass