4.2 c Flashcards
what is glass mainly composed of, how?
sand with limestone and sodium carbonate. to fuse these materials together, they are heated to extremely high temps and then cooled rapidly to form a rigid structure, but not crystalline
cullet
broken glass that can be added to the raw materials at the start of the glass-making process
how is incorporating cullet beneficial
reduces the energy, amount of raw material and time required
list characteristics of glass
1 non porous
2 non toxic
3 transparency
4 color
5 strength – low tensile but high compressive
6 brittleness
7 high hardness
8 un reactivity
9 insulator
10 100% recyclable
applications of glass
soda glass
PYREX
Toughened Glass
Laminated Glass
Fibreglass
soda glass
commercial glass, is the most commonly used
will shatter going from cold to hot or the other way
PYREX
The chemical composition of soda glass is altered by the addition of oxides which improve thermal conductivity
examples of pyrex glass
cookware, science equipment such as beakers, oven doors and anywhere where heat/cold are crucial to the design performance
Toughened Glass
When it is impacted it shatters into little pieces rather than sharp shards
examples of toughened glass
shower glass, phone screen protectors… design contexts where there is a potential for impact
Laminated Glass
layers of glass and plastic sheets between them.
When impacted the glass fragments are held in place. This prevents cracks from growing - bullet proof glass
Fibreglass
is very long strands of glass. Sometimes these are woven into mats and used as glass fibre reinforced plastic when combined with a resin (polymer)
sustainability of glass
glass is 100% recyclable and can be recycled endlessly without loss of quality
mitigates climate change (insulating glass for windows, light weighting in transportation, glass in solar panels)
saves resources (easy to recycle fully)
safeguard peoples health (food and beverages not stained by packaging)
