Share here all your information, suggestions inspiration for a extrusion machine. The more information we gather the better the machine will get.
Would a microwave or convection oven work?
(Most of those already have a motor for rotation. Just turn it sideways.)
Well what about a rice cooker? It has pa precise the temperature controller, just what plastics need, its cheap and avalable for just 12 euros, to remove the heatng parts of a rice cooker you only need a screwdriver. ( as a bonus you have a simple temperature controller too)
Personally I would go for something with temperature control…
Microwave is just getting…hot.