4.2c - Glass

The Story of Glass

Includes recycling and applications focuses on its energy-intensive production from silica sand limestone and soda ash

Composition of Glass

Made from silica sand limestone soda ash with added chemicals for properties

Importance of Glass Recycling

Scrap glass reduces energy consumption as melting occurs around 1700 Celsius

Characteristics of Glass

Includes transparency color design options strength brittleness hardness and unreactivity

Transparency

Allows light to pass through making it ideal for jars windows and decorative purposes

Color in Glass

Achieved by adding specific chemicals for tailored aesthetics

Strength of Glass

Low tensile strength but high compressive strength

Brittleness

Shatters easily due to low impact strength

Hardness

Resistant to scratches due to high hardness

Unreactivity

Chemically inert making it suitable for food storage without risk of leaching

Non-Toxic Property

Ideal for holding consumables and beverages

Non-Porous

Retains liquids and prevents moisture seepage from external environments

Insulating Properties

Does not conduct heat or electricity

Recyclability of Glass

100% and continuously recyclable

Soda Glass

Commercially common glass with medium to low thermal shock used in windows and drink bottles

Borosilicate Pyrex

Enhanced thermal conductivity for cookware science equipment and oven doors

Toughened Glass

Heat treated and cold-blasted for shatter-resistant applications like car windows

Laminated Glass

Layers of glass with plastic to hold fragments prevents crack propagation used in windscreens and bulletproof glass

Glass Fiber

Long glass strands woven for reinforced plastic used in tent poles and swimming pools

Design Contexts of Glass

Utilized for walls windows bulletproof panes scientific tools and ornamental products

Recycling of Glass

Produces cullet which lowers energy and material costs improves environmental sustainability

Color Sorting in Recycling

Glass is separated by color due to chemical composition before crushing for reuse

Environmental Benefits of Recycling

Reduces energy consumption pollution and raw material extraction