Glass

Question 1

definition of glass

Answer 1

refers to material which does not crystallise when cooled from the liquid to solid state

blends of metallic oxides (predominantly silica)

Question 2

What is glass made up of?

Answer 2

silica (sand) 70-74%
sodium carbonate (soda ash) 12-16%
calcium carbonate (limestone) 5-12%

Question 3

U-values of glazing

Answer 3

single - 5.8
double - 2.8
triple - 0.8

windows - double glazing - both conduction and convection occur - layers absorb moisture and prevent leakage

Question 4

Low- E coating

Answer 4

glazing

sunlight absorbed by the coating

Question 5

What was the first glass objects?

Answer 5

glass beads

2500 B.C.

Question 6

Annealed glass

Answer 6

breaks easily

producing long, sharp splinters

Question 7

Tempered glass

Answer 7

shatter completely under high levels of impact energy

few pieces remain in the frame

Question 8

Laminated glass

Answer 8

can crack under pressure, but tends to remain integral, adhering to the plastic vinyl interlayer

Question 9

process of making glass

Answer 9

batch preparation
batch charging
melting and conditioning (1600)
tin bath
annealing Lehr (600)
cutting area (200)
glass stacking

Question 10

advantage of glass

Answer 10

natural light
thermal insulation
fire resistance
acoustic control
reuse
recycle
variety

Question 11

disadvantage of glass

Answer 11

glare
greenhouse effect
high cost
fragility
high energy production
limited maximum size

Question 12

surface treatments of glass

Answer 12

printed
chemically coated screened
painted
laminated