APP – Purging (PEEK)

It is vital to purge your Filament Maker after each extrusion session, before stopping the flow of PEEK.

1. What does “purging” mean ?

Purging means flushing a material out of the barrel of the Filament Maker, by pushing it out with a purging material.

2. Is it really necessary to purge the Filament Maker after each use ?

Yes, absolutely.

Even if you plan on processing the same material several times in a row.

It is safe to leave Devoclean MidTemp EZ inside the Filament Maker during shutdown, but not Devoclean HighTemp nor PEEK.

3. Why do I need to purge my Filament Maker ?

To avoid irreversible clogging of the barrel and degradation of the material.

In order to shut down the Filament Maker safely, all traces of PEEK must have been removed.

Skipping the purging step can have terrible consequences for the equipment:

  • the material left inside the barrel degrades. This starts as soon as the flow stops, knowing that the machine remains hot for 2h, and that plastics are degraded by heat. The plastic molecules start breaking, the structure changes, the plastic loses its properties and burns.
  • the material crystallizes/solidifies irreversibly. It will take a bit of time until all the plastic inside the barrel becomes solid, but this process starts as soon as the flow stops. In some cases, it will still be possible to get some flow back
  • the screw becomes stuck irreversibly. This can happen with PEEK and Devoclean HighTemp.

4. First step : PEEK –> Devoclean HighTemp

There are no purging preset parameters.

You should use the same temperatures as when processing PEEK, around 400°C.

  • Wait for the hopper to be empty
  • Feed some Devoclean HighTemp
  • Wait (and keep feeding, if needed), until the output is pure Devoclean HighTemp. This should take about 20 minutes.

5. Second step : Devoclean HighTemp –> Devoclean MidTemp EZ

Once the output is pure Devoclean HighTemp at 400°C :

  • Set all temperatures on 300°C
  • Wait until the Filament Maker cools down to 300°C (do not stop the flow, but you can set a low 2RPM screw speed in order to waste as little material as possible)
  • When the hopper is empty at 300°C, start feeding some Devoclean MidTemp EZ
  • Wait until pure Devoclean MidTemp EZ comes out (you can speed up the transition by setting 15RPM)
  • You can now safely switch off the Filament Maker

6. Want to know more ?

Please make sure you read our Full Guide and become an expert of purging and maintaining your Filament Maker in good condition.

It contains more information, pictures, instructions, examples…

If you still have questions, please feel free to ask us at materials@3devo.com. It will be a pleasure helping you avoid problems.