Glass Ppt 715q5i

 It is a mixture of number of metallic silicates, one of which is usually that of an alkali metal.  It is amorphous, transparent and translucent.  It may also be considered as a solidified, super-cooled solution of various metallic silicates having infinite viscosity. It is an inorganic solid material that is usually clear or translucent with different colors. It is hard, brittle, and stands up to the effects of wind, rain or sun. Thermal and sound insulating properties are two of its most important properties .

DISCOVERY OF GLASS: • Natural glass has existed since the beginnings of time, formed when certain types of rocks melt as a result of hightemperature phenomena such as volcanic eruptions, lightning strikes or the impact of meteorites, and then cool and solidify rapidly. • Stone-age man is believed to have used cutting tools made of obsidian (a natural glass of volcanic origin also known as hyalopsite, Iceland agate, or mountain mahogany) and tektites (naturally-formed glasses of extraterrestrial or other origin, also referred to as obsidianites).

•According to the ancient-Roman historian Pliny (AD 2379), Phoenician merchants transporting stone actually discovered glass (or rather became aware of its existence accidentally) in the region of Syria around 5000 BC. •Pliny tells how the merchants, after landing, rested cooking pots on blocks of nitrate placed by their fire. With the intense heat of the fire, the blocks eventually melted and mixed with the sand of the beach to form an opaque liquid. •This brief history looks, however, at the origins and evolution of man-made glass.

PROPERTIES OF GLASS MAIN CHARACTERISTICS OF GLASS: - It is a Solid and hard material - It Has a Disordered and amorphous structure - Fragile and easily breakable into sharp pieces - Transparent to visible light - It is inert and biologically inactive material. -Glass is 100% recyclable and one of the safest packaging materials due to its composition and properties

PROPERTIES OF GLASS o Glass is used for architecture application, illumination, electrical transmission, instruments for scientific research, optical instruments, domestic tools and even textiles. o Glass does not deteriorate, corrode, stain or fade and therefore it is one of the safest packaging materials. o Glass is a very good thermal as well as sound insulating material.

TYPES OF GLASS: oSODA GLASS oHARD GLASS oOPTICAL GLASS o FLOAT GLASS oPHOTOCHROMIC GLASS oFIBRE GLASS oFOAM GLASS oULTRAVIOLET GLASS oPERFORATED GLASS oTINTED GLASS oTOUGHENED GLASS oMIRROR

SODA GLASS : It is the cheapest & most common glass. It is prepared by fusing soda ash, sand and limestone. It is also called soft glass. It fuses at comparatively low temperatures. The major disadvantage of using this glass is that it is brittle & breaks easily. It cracks when subjected to sudden changes of temperature it is used for the manufacture of window glass, mirrors, common glassware etc. It is easily attacked by chemicals. HARD GLASS : It is obtained by fusing potassium carbonate & limestone. It is used for making hard glass apparatus. It is more resistant to the action of acids.

OPTICAL GLASS : It is specially made so as to be free of strains & defects. It is used for making lenses for spectacles, microscopes, cameras, telescopes & other optical instruments.

PHOTOCHROMIC GLASS : It is a special variety of glass that temporarily darkens when exposed to bright light. It is, therefore, very useful as a sun-shield. This automatic darkening property of photo chromatic glass is because of the presence of silver bromide.

FLOAT GLASS :  It is a sheet of glass made by floating molten glass on a bed of molten tin.  This method gives the sheet uniform thickness and very flat surfaces.  Modern windows are made from float glass.  It is widely used for residential buildings, commercial complexes, furniture articles etc.

FIBRE GLASS: It is composed of minute glass rods and each glass rod resembles the parent material in all respects. It is soft to touch and it is flexible in nature. It is proof against water, fire, vermin and acids. It is a special type of glass and it is used for thermal insulation, sheets, fiber glass, reinforced plastics etc.

FOAM GLASS: It is prepared in the form of rectangular blocks. It floats in water and it can be cut like wood. It is fire proof, rigid and an excellent heat insulator. It can be used as a substitute for cork for use in air conditioning and refrigeration industries.

ULTRAVIOLET GLASS:: This glass transmits the effective ultraviolet rays even though it is not in the direction of the rays of the sun. It transmits 75% of ultra violet radiations, which is far more than common glass. It is widely used in windows of schools, hospitals ,office buildings etc.

PERFORATED GLASS: Perforations are made in sheet glass with the help of rollers. The perforations may be made during the manufacture or after manufacture. It is used for s of ventilators.

TINTED GLASS: Tinted glass refers to any glass that has been treated with a material such as a film or coating, which reduces the transmission of light through it. It is available in different shades/tints. It is mainly used in windows in houses.

TEMPERED/TOUGHENED GLASS: oToughened or tempered glass is glass that has been processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. o Used for its characteristic of shattering into small cubes rather than large shards. o It is used in buildings for unframed assemblies as frameless doors etc.

MIRROR o It is a surface capable of reflecting sufficient undiffused light to form an image of an object placed in front of it. It is also called looking glass. o A sheet of glass with a metal coating on its back, that reflects an image of an object placed in front of it .

Effects on glass FROSTED GLASS

ETCHING ON GLASS (PLAIN ETCHED AND SILVER FROSTED EFFECT)

GLASS BLOCKS

STAINED GLASS

CHART: NAME: 1] FLOAT GLASS

2] HEAT REFLECTIVE GLASS

3] TINTED GLASS

SIZE:

RATES:

3mm

Rs.18/sq-ft

4mm

Rs.24/sq-ft

6mm`

Rs.38/sq-ft

8mm

Rs.60/sq-ft

12mm

Rs.80/sq-ft.

4mm

Rs.55/sq-ft

5mm

Rs.70/sq-ft

3mm

Rs.28/sq-ft.

4mm

RS.34/sq-ft.

5mm

Rs.42/sq-ft

NAME

SIZE

RATES

BAJRA GLASS: A) Plain glass

3mm

Rs.14/sq-ft

B) Coloured glass

3mm

Rs.20/sq-ft

2] GLASS BLOCKS

7/7 inch

Rs.110/block

1] DECORATIVE GLASS

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