Denford Software & Machines

We recently got an old injection molder donated to our department and I was trying to think of a way of incorporating into our CAD (Pro/Desktop) & CNC (Denford Compact Router) curriculum. I have found resources that explain how to setup a mold in Pro/Desktop, but they don't provide any detail about the next phase. What material would be suitable for a plastics injection mold machine? My first thought was MDF or Plaster of Paris, but I am not sure. Would MDF take the amount of heat? Is Plaster of Paris a suitable material to put in our CNC router? The product we would produce would just be small gears or custom plastic wheels.

Thanks to anyone who can provide suggestions,

Travis East
Indian Creek High School
Trafalgar, Indiana
USA

MDF is OK for casting pewter or other low-melting point metals - we have seen this done before.
The problem will be whether the pressure from the injector would be too high for MDF

Our old PolyLab machines were a basic plastic injection moulding machine - these have been used with tool-steel moulds (expensive) and aluminium moulds.