Materials for a Purpose

Materials for a Purpose

Properties of Materials

• Hardness: The ability of a material to resist scratches or indentation from sharp objects.
• Toughness: The capacity of a material to resist damage, like fracture due to high-impact force.
• Ductility: Refers to the extent to which a material can be stretched without breaking.
• Malleability: Represents how easily a material can be shaped or formed when subjected to pressure.

Selection of Materials

• Need to understand the material’s properties, like hardness, toughness, heat resistance, etc.
• The selection also depends on the purpose of the material. For instance, ceramics are used for dishes due to its high strength and heat-resistance.
• Cost-effectiveness is crucial when selecting materials.

Food Packaging Materials

• Plastic: Widely used due to its light weight, flexibility and resistance to moisture.
• Metal: Ideal for canned foods, providing a long shelf life.
• Glass: Excellent barrier against moisture and gases, preserves food perfectly.
• Paper and Board: Used in boxes and bags. They are cheap, lightweight and renewable.

Biomaterials

• Polylactic acid (PLA): A type of biodegradable plastic used for food packaging.
• Natural Fibres: Like cotton, silk, wool that are used in clothing and textiles.
• Bio-glass: A biocompatible material used in medicine, for example, in bone grafts.

Smart Materials

• Temperature-responsive polymers: Change their properties with a change in temperature.
• Photochromic materials: Respond to light and change their colour.
• Shape-memory alloys: Remember their original shape and return to it when heated.