Types of Materials (Junior Cert Applied Technology): Revision Notes

Plastics in Applied Technology

Plastics are key in Applied Technology projects. Important plastics include Acrylic, PVC, HIPS, and ABS. They are popular due to their versatility, cost-effectiveness, and ease of use. Knowing these differences helps in choosing the right one based on durability, flexibility, recyclability, and heat resistance.

Definitions

• Plastics:

  • Made from crude oil and gas.
  • Lightweight, waterproof, and versatile.

• Thermoplastics:

  • These soften and can be reshaped with heat.
  • Recyclable, including Acrylic, PVC, HIPS, and ABS.

• Thermosetting Plastics:

  • Set permanently with heat.
  • Used when heat resistance and durability are needed.

Categories of Plastics

• Primary Categories:

  • Thermoplastics: Recyclable and reshaped, including Acrylic, PVC, HIPS, and ABS.
  • Thermosetting Plastics: Heat-resistant, keeping shape once set.

• Comparison Table:

  Feature	Thermoplastics	Thermosetting Plastics
  Recyclability	Can be recycled	Non-recyclable
  Heat Treatment	Soften with heat; can be remoulded	Hardens with heat; cannot be remoulded
  Common Applications	Packaging, containers, car parts	Kitchenware, electrical appliances

• Examples:
  • Thermoplastics: HIPS used in electronics.

Common Plastics for Tech

• Acrylic:

  • Clear and strong.
  • Used in signs and displays.

• PVC (Polyvinyl Chloride):

  • Tough and bendable, used in pipes and building.

• HIPS (High Impact Polystyrene):

  • Tough, used in toys, casings.

• ABS (Acrylonitrile Butadiene Styrene):

  • Light, used in cars and electronics.

• Properties and Applications:

  Plastic	Properties	Applications
  HIPS	Strong, low cost	Casings, toys
  ABS	Shockproof, shiny finish	Toys, brake systems
  Acrylic	Hard, smooth	Signs, displays
  PVC	Tough, bendable	Pipes, construction

Shaping Plastics

• Vacuum Forming:

  • Heat plastic and shape it with a vacuum.
  • Good for dashboards and packaging.
  • 

• Bending with a Strip Heater:

  • Heat to bend plastics at angles.
  • Good for precise shapes.

• Cutting:

  • Use saws and CNC machines; wear safety gear.