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Topic: PLA vs ABS! My experience

I'm not sure If this is in the right place but I think I'll drop it here for now! smile

When I got my solidoodle I was enjoying my entry into an exciting new world.  I was a bit biased against PLA at first but after a couple months of ABS printing, I switched over to PLA for some experimentation.  After a few HOURS (Take note of this) of printing, I was getting someone precise models in white and black and having quite some fun with it.  I continued to use PLA for a few months, although I was plauged with clogging every couple weeks and had to order a new hot end, and then an E3D hotend.
I got the new E3D and installed it in a few hours and then spent another couple re-learning how to print in PLA.  Now 2 weeks later I still get bad quality prints from it.  Before the E3D I was doing better quality wise but here is what I found

PLA:
Much more brittle
Seems stronger though
lower melting temperatures,
MUCH more tuning necessary
Biodegradable (disolves over time in a natural environment (Good and bad depending on the use)

Now just tonight, I decided to try ABS again.  After pushing 500mm of ABS through the nozzle at 215C (just to make sure I got most of the PLA out) I flipped over my blue painters tape covered piece of glass, and put on some kapton.  After tinkering with the temperature for 10 minutes, im now getting prints that have nearly flawless sidewalls, and the sharpest details I even saw with the original solidoodle brand hotend! So:

ABS:
More flexible
Higher melting temperature
Much sharper and smoother (when need be) models
After pushing out old PLA, only took 10 minutes of temperature play to start printing extremely high quality prints!
Is NOT biodegradable (good and bad depending on the use)
Is said to let off toxic nano-particles
-NOTE: I solved this with a simple ventilation system.  Tests though have shown 10 hours of running with ABS is equal to smoking  single cigarette, since cigarettes put out the same gases.

I figured I would leave this here for people debating what to use for their printer and for anyone with a curious mind!  Comments and other experience stories are welcomed!  Photo's are attached to show examples!

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Re: PLA vs ABS! My experience

Photos didn't make it.... Otherwise good info I think it's time to go have a smoke big_smile

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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Re: PLA vs ABS! My experience

I haven't seen anyone do a back-to-back comparison on strength for ABS and PLA (y'know, excuses to play with Instron machines!), would make for some interesting stress strain diagrams I think. Anyone got a line?

FordGalaxie wrote:

Tests though have shown 10 hours of running with ABS is equal to smoking  single cigarette, since cigarettes put out the same gases.

Forgive me, but this seems a bit of a stretch at face value... 'Equal' is a pretty strong word, and I'd bet on there being a whole bunch of toxic gases released by cigarettes that aren't by 3d printers... Do you have a link for this?

Keep up the ventilation though, ultra-fine / nano particles definitely something to keep an eye on (don't be alarmed though...):
http://www.sciencedirect.com/science/ar … 1013005086

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi

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Re: PLA vs ABS! My experience

Well I dont mean they release ALL the same gases that are in cigarettes are released by a printer.  I mean the gases that ARE released by the printer, are the same as SOME of the ones released from cigarettes.  I cant remember where I saw the link but if I find it ill post it!

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Re: PLA vs ABS! My experience

Got a peer reviewed paper to back up those claims about said tests?

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons tongue

6 (edited by elmoret 2014-02-11 02:51:18)

Re: PLA vs ABS! My experience

Serin wrote:

Got a peer reviewed paper to back up those claims about said tests?

http://gizmodo.com/3d-printing-indoors- … -894193776

Problem is, UFPs can be anything really. Sneezing makes UFPs.

EDIT: Here's a pretty good paper, echoing most of my research during the Filastruder design process:

https://dl.dropboxusercontent.com/u/178 … er1995.pdf

They cooked a kg of ABS at 260C and piped it to rats. They detected <1ppm HCN, around 50ppm CO, and roughly constant CO2/O2.

As reported by Schaper et al. (1994), when these resins were heated at a rate of 20C/min from room temperature to 900C they reached a temperature at which major decomposition occurred; this was defined as the critical temperature. For ABS, CP (or HP), and PVC, the critical temper- atures were 375C 325C and 250C respectively. Thus, the processing temperatures of 285C for CP (or HP) and 230C for PVC were close to the critical temperatures, and it was not surprising that decompo- sition occurred during isothermal heating. With ABS, the same logic may be applied; the processing temperature of 260C used in the present study was almost 100C below its critical temperature which was why little, if any, decomposition occurred. It is clear that de- composition of CP, HP, and PVC will occur if the processing temperatures given in Table 1 are used in the workplace. Furthermore, if these temperatures are exceeded (e.g., cleaning of molds, accidental overheat- ing), then there will be greater concerns with release of TDP. As concluded by Schaper et al. (1994), ABS exhibited excellent thermal stability up to 375C and this stability should be advantageous in the workplace for health and safety reasons.

This is why I limited the Filastruder's heater size, to ensure a maximum temperature of less than 260C even if the controller failed full on.

With that said, I have my 3D printer ducted to atmosphere with a fan set up to give negative pressure, and the Filastruder in a 2 car garage with a CO sensor mounted a foot away. The CO sensor has never registered higher than 0ppm (except when I pull my truck into the garage - its hit 50ppm then)

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Re: PLA vs ABS! My experience

Thanks for the links, Elmoret.
Probably time I built an enclosure anyway...

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons tongue

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Re: PLA vs ABS! My experience

If you want to use PVA water soluble support from a second extruder, PLA is the part material for you.  If you have a second extruder that can handle high temperatures (up to 260C at least), you can run HIPS as a support that will dissolve with d-Limonene and ABS as a part.  The PVA PLA combo requires you leave the bed heat off.  The HIPS ABS combo requires high bed temps (110C-120C)