Glass

Glass is a non-crystalline, hard but brittle material widely used in daily life. It is formed from a mixture of silica (SiO₂), commonly found in sand, and silicates.

History of Glass,

Glass was discovered accidentally by Phoenician traders cooking in the desert. They noticed a transparent material formed when heat combined sand and limestone, leading to the discovery of glass-making. This observation paved the way for the glass production process.

1. Ingredients

• Mixture of sand (SiO₂), soda, lime, and magnesium oxide.
• Discarded glass pieces are added to reduce the melting temperature.

2. Process

• Heating: Sand melts at 1700ºC. Adding soda and lime lowers the melting point to 850ºC.
• Melting: The mixture is heated to 1500ºC until all ingredients are liquified.
• Cooling: The molten mixture is rapidly cooled, forming a homogeneous, amorphous, and transparent material called soda-lime glass.

Glass manufacturing process

1. Glass becomes soft when heated and can be moulded into any shape.
2. The density of glass varies depending on its ingredients.
3. Glass is a poor conductor of heat, and rapid temperature changes can cause it to crack or break.
4. It is a bad conductor of electricity, making it ideal for electrical insulation.
5. Glass allows most light to pass through, providing transparency.
6. Oxides like chromium, vanadium, or iron in glass absorb light, reducing transparency.
7. Glass is chemically inert, resisting reactions with most substances.
8. It is durable and resistant to weathering over time.
9. Glass is recyclable without losing its properties.
10. It can be tinted or treated to modify its optical and thermal properties.