extruder

Hi i don't understand the function of the The drive screw.. Can you give me more information..? please. thank you very much

How else can plastic be pushed out of the extruder? It's too viscous to just pour out usefully under gravity.

The drive screw grips the filament well (so it won't slip), and provides a fair bit of mechanical advantage; other mechanisms for feeding filament into the heater (such as pinch wheels) are simpler but don't generally seem to provide enough force.

There is some more information on larger scale plastic extrusion here:

[en.wikipedia.org]

A standard screw is designed to force it's way through material. In extrusion, the screw rotates in a fixed position and the 'thread' of the screw will drive the material fed into the system forward to the extrusion die.