Transcript Glass

Glass
Group 6
Bungato
Enriquez
Lapa
Magtalas
Mancilla
Necessario
Posadas
Tamara
How it started…
Glass was first manufactured in open pits in
ca. 3000 B.C. until the blowpipe was invented
in ca. 50 B.C.
Nowadays, we
also use molds
and machines.
Characteristics of glass
• It is brittle.
• Discoloration signifies wear.
• Can be formed either with molds or
blowing/manipulation.
• It is non-conductive.
• It can be either transparent, translucent or
opaque.
• It’s chemical and physical properties remain
unchanged after heat-treatment.
Production
• While pure silica can be made into glass for special
applications other substances are added to common
glass to simplify processing (ex. Sodium Carbonate in
soda-lime glass).
• As well as soda and lime, most common glass has other
ingredients added to change its properties (ex. Lead,
Boron, Iron & Barium).
• Besides the chemicals mentioned, in some furnaces
recycled glass ("cullet") is added, originating from the
same factory or other sources. Cullet leads to savings not
only in the raw materials, but also in the energy
consumption of the glass furnace.
Production
• Following the glass batch preparation and mixing the raw
materials are transported to the furnace.
• After melting, homogenization and refining (removal of
bubbles) the glass is formed (ex. Container glass for
common bottles and jars is formed by blowing and pressing
methods.).
• Once the desired form is obtained, glass is usually annealed
for the removal of stresses.
• Various surface treatment techniques, coatings, or
lamination may follow to improve the chemical durability,
strength, or optical properties.
• Glass polymerization is a technique that can be used to
incorporate additives that modify the properties of glass
that would otherwise be destroyed during high
temperature preparation.
Application
• Ordinary glass is prevalent due to its transparency to visible
light.
• Laboratory equipment are often made of borosilicate glass
for its low coefficient of thermal expansion, giving greater
resistance to thermal shock and greater accuracy in
measurements. For high-temperature applications, quartz
glass is used, although it is very difficult to work.
• Glass is commonly used in buildings as transparent
windows, internal glazed partitions, and as architectural
features.
• It is also possible to use glass as a structural material, for
example, in beams and columns, as well as in the form of
"fins" for wind reinforcement, which are visible in many
glass frontages like large shop windows.
Application
• However, glass cannot carry heavy loads because it’s
brittle and has a tendency to shatter on impact.
• Glass can also be used for insulation (ex. Fiberglass &
Foamed glass.)
• Some glass (ex. SiO2 glass) can absorb UV rays.
• Glass mirrors, lenses or prisms.
• Glass can also be manipulated into art-forms
(ex. Glass blowing, glass
molding, etc.).
Types of Glass
Sheet Glass
Energy Efficient Glass
Self Cleaning Glass
Float Glass
Types of Glass
Patterned Glass
Toughened Glass
Laminated Glass
Wired Glass
Types of Glass
Mirrors
Picture Frame Glass