Isolator Guide cooling

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1

Hi guys,

According to several people (including Velleman) the isolator guide made of PEEK needs to be cooled to prevent melting it.
But after googling the PEEK material i saw that the melting temperature is at 343 degrees (according WikiPedia).

So why does it needs to be cooled?

2

Hi,
I guess, that the filament itself will melt and block the tube/nozzle. so cooling the isolator, you actually cool down the part of the filament.
If I have had blocked nozzles, always the material inside the PTFE tube as melt and thicker than expected.

3

What is more important is that the thermistor reads the correct temperature. If it is mounted incorrectly for example, the thermistor might read 220°C, while the actual temperature is 350°C. Seemingly melting the isolator guide at “220°C”.

4

Even further - while PEEK may melt to a liquid at 343 degrees, like any plastic it very probably starts to soften and deform at a significantly lower temperature.