ReDeTec ProtoCycler - Disco Purge; Purge Tips

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5.1.2 Disco Purge
Disco Purging means we are going to thermal cycle the ProtoCycler to help transition from one material to another.
It is strongly recommended to remove nozzles for the duration of a disco purge and replace it only when purging is
complete with a new nozzle. Removing nozzle will require preheating in order to soften the plastic inside to release
the nozzle. Please refer to Table 1 for nozzle removal temperatures.
Steps:
1. Remove nozzle and follow steps 1-8 of section 2.1 (Short Purge).
2. After your first 10 minute cycle, immediately set your temperature slider to 0
o
C and auger speed to 50. The
auger will limit its speed as the extruder cools and material melt resistance increases.
3. Once the extruder reaches the temperature of the “Lower Temperature” material’s nozzle removal
temperature (see Table 1 for reference), increase temperature back up to the Purge Temperature. Do not
increase the auger speed until the temperature has reached (the minimum) Preheat Temperature to avoid
stalling the motor.
4. When up to Preheat Temperature, increase auger speed back up to 75 on the slider.
5. Purge for 10 minutes.
6. Repeat steps 2-5 until completely transitioned to the new material.
5.3 Purge Tips
1. Purging plastic – especially from a warmer temperature plastic to a cooler temperature plastic – can take a
long time. It is recommended that you avoid or mitigate the need for switching plastics as much as possible.
2. Use different colorants as an indicator when purging to distinguish between old and new plastic.
3. When purging dissimilar materials, the general rule is to look at the MSDS documentation to see where the
extrusion (purge) temperatures overlap. Importantly, do not increase temperature so high that you burn
the old or new material inside of the extruder. But what if there is no overlap in the two materials’
processing temperatures? If this is the case, please contact Technical Support immediately for assistance,
stating what plastics you are transitioning from and to. ReDeTec will advise further.
4. Having an extra nozzle (with breaker plate and screen) is especially useful when switching between
materials to not contaminate the new material!