Extruderinsulator

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Materials

Peek or PTFE

Benifit of Peek

no dangerous fumes if over heated.

I have 16mm diameter PEEK rod.

Disadvantages of PTFE

dangerous fumes if over heated

I dont have any PTFE.

The Original Reprap Mendel design:-

Thermal-barrier.png

New Idea for a PEEK version of the insulator.

Diffrence from original.

1/ The top of the insulator is D shaped.

2/ The insulator mounts through a 6mm thick D Shape hole to stop twisting.

3/ The insulator is held in place with an E clip

4/ The filament clearance hole is bigger at 4.2mm

5/ The heated barel threaded length is much shorter.

6/ The heated batrrel is 25mm long

PEEK Idea.png

Calcultaions

Calculations for the thermal insulation of these insulators calculated here given these constatnts.

PEEK = Thermal resistance 0.25 W/m.K

PTFE = Thermal resistance 0.25 W/m.K

ABS = Thermal resistance 0.188 W/m.K

PLA = Thermal resistance ???? W/m.K

Air = Thermal resistance 0.025 W/m.K

But the thermal resistance of PTFE changes at 232°C. exert taken from http://www.sump4.com/publications/conf015.pdf

"CONCLUSIONS A simple and accurate apparatus for the determination of thermal conductivity was built and used to investigate the effect of processing and composition on the heat transport behavior of PTFE/glass fiber mats. Ancillary measurements indicated that the thermal conductivity of PTFE increased with increasing crystallinity at 232°C."