APP – Pre-heating and transition (PET)

Because many different grades of PET exist, it is difficult to define one set of perfect settings for all of them.

Starting your first experiment with inappropriate settings might result in the clogging of your Filament Maker.

It is therefore important to start the experiment with a good transition at the right temperature.

1. Having the right material inside the barrel

PET cannot be left inside the Filament Maker during shutdown, so the barrel will be filled with another material when the experiment starts.

The barrel will most likely be full of Devoclean MidTemp or HDPE. It is recommended to start with HDPE.
(If the barrel is full of Devoclean MidTemp, you can therefore transition to HDPE at 270°C).

2. Starting settings

It is always a good choice to start with:

  • Temperatures = 270°C. This is quite high for PET, but the risk of clogging is lower.
  • Screw speed = 5RPM. The flow is often the most stable between 3.0 and 7.0RPM.
  • Fancooling = 30%. This parameter does not really matter at this stage. PET can solidify very fast, sometimes inside the nozzle, or at the tip of it, which is why it is wiser to start with low percentages.

Tip : Make sure that the  fans are pointing as downard as possible ; not horizontally nor straight up toward the nozzle.

Tip : Make sure the magnetic plate is covering the hole around the nozzle.

3. Transition

Transitioning from HDPE to PET often takes a lot of time. During this transition, transparent HDPE and transparent PET can become badly mixed into a blurry output.

In order to save some time, you can set the screw speed on 15RPM.

The output must look like the bottles you shredded : probably transparent, clear, maybe with a blue/green tint.