1 Topic by bbriggsgeek

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Topic: Brittle Filament

The filament that I'm extruding seems to be more brittle than much of the stuff I've bought.  If I bent it at a sharp angle it tends to break instead of bruise.  Printing is ok but my prints are kind of brittle too. The walls crack if there is much pressure on them at all. 

I'm extruding 3mm ABS from OSPrinting at about 181 degrees.

I do think I messed up my calculations for the masterbatch so that could be the issue.  I think I used about twice as much masterbatch, also from OSPrinting, as I should have.

Any thoughts?

2 Reply by elmoret

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Re: Brittle Filament

That would do it! Have you extruded any without master batch? How much master batch did you use? With how much resin?

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3 Reply by bbriggsgeek

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Re: Brittle Filament

The natural I've been doing is much better but is still a little more brittle than the filament I bought before.

4 Reply by elmoret

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Re: Brittle Filament

bbriggsgeek wrote:

The natural I've been doing is much better but is still a little more brittle than the filament I bought before.

A popular resin used in filament is PA-747 by my readings, which may be less brittle - I haven't looked into it. OS Printing sells MG94 which from what I've read is what Stratasys uses, and it is a pretty high MFI plastic so it is a good fit for extrusion at higher speeds (it flows more easily). You could try some PA747, but expect it to extrude a bit slower.

Other possibility is excessive moisture in the pellets, you could try drying them.

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

5 Reply by bbriggsgeek

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Re: Brittle Filament

I thought it might be a different formula for ABS.  I wanted to ask the question because I've seen it asked of others when they were talking about other problems.  I wanted to make sure it was not indicating some other issue I'm having.

6 Reply by jhhoffman

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Re: Brittle Filament

Having a similar problem but it just seems to be in patches of the filament, do you think it could be caused by masterbatch pellets being in close proximity to each other in the mix, my ratio was 2 grams to 100 grams.

7 Reply by bbriggsgeek

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Re: Brittle Filament

The masterbatch ratio can be a factor.  One batch I did, I miscalculated the ratio and had about twice as much as I needed.  That didn't work well.  There are a few different formulas for ABS and I have found the MG94 was the most brittle. 

If it's in patches, my guess would be the masterbatch.