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jes / 3d-metal-printing

Notes and information about 3d metal printing
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Debinding with dichloromethane #5

Open jes opened 5 years ago

jes commented 5 years ago

The professional FDM-and-sinter printers include a "debind" step in between printing and sintering, where the binder is removed but the metal powder somehow retains its shape.

I soaked a bronze-PLA part in dichloromethane for an hour, and the DCM did an excellent job of dissolving out the PLA, but the bronze powder didn't retain its shape, so this isn't really looking viable.

jes commented 5 years ago

The professional filaments aren't just PLA and metal, they are PLA and wax and metal, and the debind only removes one of the PLA and the wax.

Stavros suggests rubbing a load of wax all over the filament so that it mixes together in the hotend, and then dissolving out the PLA with DCM to see if the wax-and-bronze mix still keeps its shape.

When I tried out the DCM, it visible started dissolved the PLA very quickly, so it also might be worth diluting the DCM with something else to slow down the reaction if that makes the part stay more stable.

jes commented 4 years ago

Before trying out DCM, I tried soaking a PLA part in isopropyl alcohol, but it had no visible effect. I've just taken it out (so it was in there at least 23 days, probably closer to 30 days). There is no visible difference whatsoever. It has, however, gained about 0.2 grams in mass, presumably by soaking up IPA into the gaps between filament inside. I assume this will drop over time as the IPA evaporates off.