4.2 c Glass

Materials that make up glass

Sand (pure form is polymer), soda ash (sodium carbonate), limestone (calcium carbonate)

Characteristics of Glass

• resits scratching under normal conditions

• brittle

• electrical insulator

• cheap

types of glass

• glass fiber

• lead fiber

• lead glass

• commercial glass also known as borosilicate glass

Glass making process

materials fuse together at a melting temperature, and cool as a ridged structure. The soda ash makes the glass water-soluble, so limestone is added to make it more durable.

Cullet

glass that has been crushed into very small particles ready for re-melting & recycling

Laminated glass

2 parts of glass held together by a plastic sheet. (vacuumed & melted together).

Tempered glass (toughened glass)

heated up 160 and cools down rapidly (quenching) stronger (improved resistance to shock and cold temp).

Recovery Process of glass

1. recycling

2. collection

3. purification

4. finning

5. cullet melting

6. forming

7. end products

Clear glass (recycling)

stays in country normally

green glass (recycling)

sent to spain or france for wine & beer bottles

Excess glass (recycling)

gets used for cemente in a powder.