recycleBOT

Also:

Tomorrow (1st of June) Would like to extrude some plastic through the screw extruder and see if it has any issues.

In manufacture they use a screw with a variable thread and spacing to increase pressure, move material in different states and maintain temperature within the chamber.

Ive had a really good look around in town and the hutt for a screw or orger, at any place I could think of, as well the ideas of every business i walked into. I couldn't find exactly what would be used and it seems they are usually custom made for their purpose.

The screws were either far too large, thread depth was too small or angle of thread was too large and would require a high pressure to move.

And so far the best suited is a 8mm wood orger for drilling holes - run in reverse.

If this does not work a 10-15mm Coach Screw may be a good replacement.

I also think Ive underestimated the amount of pressure that can be required within the chamber to extrude the plastic, in a few different machines they use COOLING only because the large pressure causes over heating of the plastic within.

If it requires heating it is usually done at the chamber close to the die and uses the radiating heat along the chamber to melt the plastic at a slower rate making it mix better. As the plastic moves along the chamber it will absorb heat from the outside and help to stop overheating towards the hopper.

Hopefully, at the moment the steel chamber will give us enough control over the temperature along it.

On the extrusion side with our current screw configuration, some upgrades might be

*A heat separation section between the start and end of the die to help cool and keep the plastic in the die shape (high temp plastic, brass,copper which is 5 times less thermally conductive as steel or ceramic - i haven't check its thermal capacity yet)

*A vent to reduce air within the melt section(a vertical metal tube with a plate at the top that has tiny holes or a porous material)

*A screen inside part way down the melt section to help clean the Plastic as it moves along the chamber (Metal Plate with holes in it)

This also helps with re-aligning the chemical bonds within the plastic and a possible avenue to make re-melting easier within the makerbot and the recyclebot process

*Change of material for the Chamber to better control temperatures.

*Screw Replacement.

And further down the track and easy way to assemble/clean/clear material and replace parts within the extrusion chamber and screw assembly.