Chapter 1 - Glass

Question 1

Lime-soda glass

Answer 1

Made from a mixture of sand, lime and sodium carbonate, heated to 1500°C.
Used for window panes, storage jars and bottles

Question 2

Float glass

Answer 2

Sheet Glass – is produced by floating molten glass on a bath of molten tin. The flat surface of the molten metal gives the glass it’s flat smooth surface.

Question 3

Plate glass

Answer 3

A high quality glass of few impurities that has been rolled and polished. Uses include mirrors and large windows

Question 4

Cullet

Answer 4

Glass that has been crushed into very small particles, ready for re-melting and re-cycling

Question 5

Blowing

Answer 5

Used to produce an air bubble in the first gather of glass, then to enlarge the ‘bubble’ to produce the final object. Sometimes blown into a mould for uniformity.

Question 6

Slumping

Answer 6

A process where sheet glass is heated to a temperature where it softens and is allowed to take the shape of a mould.

Question 7

Lehr

Answer 7

A furnace in which hot glass (about 500°C) is placed after working, enabling it to be brought down to room temperature very slowly

Question 8

Toughened glass

Answer 8

Glass is heated uniformly and then rapidly cooled by air jets. This causes the outside surfaces to be under compressive stress, while the inside of the material is in tension. External forces must overcome these stresses to shatter the glass.

Question 9

Lead glass

Answer 9

When lead is added to glass, it improves clarity and the ability to reflect light (refraction). Products include optical uses such as prisms and lenses.

Question 10

Pyrex

Answer 10

A well-known, heat resistant glass, containing boron (Boro-silicate glass)

Question 11

Boro-silicate glass

Answer 11

Pyrex