Molding and Casting

Format: Lecture.

Learning Outcomes:

Students will be able to demonstrate knowledge of materials and different types of molding and casting techniques and safely working with these principles.

Introduction:

• Examples of molds and casted parts
• Limits and challenges of this technique

Safety

• How to handle materials safely
• Setup and space
• Waste management

Materials

• low-temp wax
• machineable wax
• rigid foam
• gesso, hot air
• alginate gel
• urethane rubber, plastic
• silicone
• PDMS (polydimethylsiloxane)
• latex
• thermoplastic, thermoset polymers
• calcium sulfate
  • desicant, coagulant, plaster, gypsum, drywall
  • DryStone
• Portland cement
  • calcium silicate, aluminum/iron oxide, calcium sulfate
  • Hydro-Stone
• metal casting
  • Cerrotru Zamak aluminum
  • clay sand
• glass
• ceramic
• food

Types and mold making

• injection (sprue, runner, gate, vent, parting line, flashing)
• insert
• vacuum
• blow
• rotational
• flexible, soft
• parts

Processing

• testing
• mixing
• pouring
  • starting
  • filling
  • vent location
• bubbles
  • vibration, vacuum, pressure
• curing
  • polymerization
  • cross-linking
  • hydration
  • endothermic, exothermic
• demolding
  • taper
  • release agents
  • dilute dish soap, vaseline, talc, ...
  • deformation
• storage
• shelf life

Post processing and finishing

• Sanding, smoothing
• Painting, closing, protection

Assignment

Create a mold and cast a part from it.