Filament air pockets

I have been printing for close to 2 years with no major jams in my BudaSchnozzle (normally a little pressure on the filament pushing it into extruder fixed all my minor jams) until now. I bought some filament from Maker Shed and after a very short time I got a jam like never before. I ended up tearing the whole hot end apart and broke pieces of it.

I wondered if the filament was at fault so I started looking at it closely and by breaking it in what felt like weak spots I found air pockets in the center of the filament, lots of them. I wonder if this might have something to do with the clogging I got?

I ordered another Budaschnozzle (2.0 this time from Lulzbot) but I am weary of using this filament anymore and I have 2 rolls from them. I was actually looking for debris in the plastic when I found the air pockets. I found 3 pockets in 4" piece of filament.

I normally order my filament from Ultimachine but they were out of the color i needed.

Forgot to mention, it's 3mm ABS

Yes those air pockets are all too familiar - they shouldn't be there of course but I don't know whether you can blame the filament or not for the jams. I've had that problem but it seems to print ok for me. Maybe the air inside the filament expands with the heat and swells it causing a jam?

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Waitaki 3D Printer

Yea, that's basically what I was thinking but I don't know. Hopefully someone that knows will chime in.

Bubbly Filament has been a problem for me.

I started with a .35mm nozzle and bad/bubbly filament. The bubbles would build up in the hot end and cause enough back pressure to strip the filament.

When I switched to known good quality filament. Printing went fine.

Later I ordered a .5mm nozzle and tried my left over rolls of bad/bubbly filament on that.

It sounded like popcorn as the bubbles made it through the .5mm nozzle and you could see gaps in the layer where a bubble had passed, but it printed the stuff.

I do my best to avoid plastic with lots of bubbles.

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Komb'
Glankonian Protoforms

Post the name of the suppliers so we can avoid purchasing from them.

Mine was Maker shed (as I mentioned).

Here is just a sample of my 3mm ABS from them.

Thats nasty..

Would you mind doing a little experiment (this is off the cuff, so there may be a better way)

You should be able to weigh a known small volume of solid filament. Then work out the volume of your remaining filament and weigh that

You should be able to calculate how much weight is missing and from that the volume of plastic that is missing.

Just to see... how bad it really is.

LulzBot has good filament too!

-Jeff

Good to know.