Wednesday, March 08, 2006

Post extrusion treatment of filament...

Reviewing the on-line literature about producing monofilament it would appear that for CAPA and polymorph at least we could use a heated quenching bath that would keep the filament very near the melting point of the polymer. If we regulated the temperature of the bath with enough care we might well be able to straighten and stretch the polymer to a proper diameter in one go. That would certainly reduce the complexity of the system.

3 comments:

jgeorge said...

One possibility for cheap interchangeable extruder heads would be wire feed welding tips. They come threaded on one side and in fairly close tolerances. Here is a link for some 2.4mm tips. Pretty cheap for 10 of them. I'm not sure what the current size of the whole is on the current reprap heads, but you can get welding tips down to .023" about .584 mm. This might be a good way to set a standard extruder head size. Forrest, the extruder looks great! Keep up the good work.

plaasjaapie said...

It's funny you mention those. I was buying welding rods for my tiny welding set a few months ago and had exactly the same thought. :-)

Brett said...

Alternatively you might look into pop rivet gun tips.

Looking good, and I think your strategy of quenching immediately, then drawing down after tempering in a water bath, is a good idea, in as much as you probably don't want to run at the pressures necessary to extrude at the higher visicosity needed for one step sizing.