Plastic recycling
Description
Build a plastic recycling machine to make 3D printable filament for the Ultimaker and other people's printers.
First (optional) step of the process is to melt plastic parts (such as bottle caps, failed prints, packages) into plastic pellets. This can be done by putting parts inside a heating recipient having a hole at the bottom. An irregular thread of material will come out and be sliced into small pellets.
Next step is to transform pellets or plastic parts (if they are small enough) into 3D-printable filament. This is performed by the extruder. An extruder is constructed from essentially two parts: a feeding mechanism, and a heater - chopped plastic parts or pellets are fed from a container into the feeding mechanism, which then pushes the plastic slowly through the heater to create the filament.
Contents
Goal
- Recycle failed/old prints and extruded plastic
- Recycle other plastics, such as PET bottles (caps), etc
- Experiment with new colors and materials
Obstacles
- Get a filament of repeatable thickness
- More complex = more difficult
- Ventilation preferable for ABS
Parts needed
| Part Name | Description | State |
|---|---|---|
| Tube | Part where the material will flow trough. Which material should we use ? (Aluminium/ (Stainless) steel) ?
Also we will have to be able to dig holes to put the temp sensors inside. |
Got ~1.5 m of dia. 20mm aluminum / 1.5mm thick |
| Auger | Screw pushing the material | Just bought one of those on Ebay |
| Motor | Makes stuff move | Needed |
| Heating element | Nichrome wire ? Ceramic heaters ? Quite cheap on ebay.
This will be controlled by a thermostat (when the tx is above a defined point we shut it down). Find a way to attach this (high-temp resistant tape ?) and isolate from the outside. |
Bought 3.048m of G28 nichrome wire. |
| Thermometers | Get the internal temperature in different places of the tube (rear, middle and nose for example). | Got 1 DS18B20 |
| Extrusion nozzle | Transforms the heated plastic into a regular filament suitable for the printer. | Needed |
| Cooling system | "From liquid to solid in a trice !". Air/water/oil ? | Needed |
Resources
Extruders
I'm guessing we should build something in between - not too simple but not too expensive either.
Misc
- Color filament
- Filament recycling detailed research paper (noskill)
- Broyeuse extrudeuse domestique (noskill)
Progression
- 2013/11/22 - Starting experiments :).
- 2013/11/27 - Measure the temperature we can have with the current setup. Are there other ways to use the nichrome wire (on the extrusion head/on the tube/both) ? Also start experiments for the part that will transform HDPE into pellets (shattering vs melting i.e.). What's the best way to have both parts (recycling and filament making) in the same machine ? Also: plans, plans, plans - use a paper shredder to break used and new plastic into small bits.
- 2014/01/17 - Added a metal top on the end with a 3mm brass extrusion nozzle soldered to it. Next step is adding motorization and automation (i.e. temperature regulation)
- 2014/01/30 - A more polished version of the metal parts will be made by User:noskill's school polymecanics. The heated part and the nozzle will be removable.
