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OMG, My PLA filament was actually ABS!

Posted by Yamster 
OMG, My PLA filament was actually ABS!
August 23, 2013 04:14PM
Yesterday I was wondering what type of plastic the free sample I have received was. Naturally, I posted a question in this forum, and also Googled a bit.

One of the ways to tell them apart was the smell test - how sweet PLA smells when melted, and how "plasticy" ABS smells when burnt.

This made me wonder... the one and only PLA plastic spool I have ever owned and used (I'm relatively new) is the black PLA I've ordered with my printer kit. Since I started printing, however, I don't remember ever smelling anything close to sweet or cooking oil. If anything, I smelled burning plastic a few times.

So.... I decided to check the order invoice email..

"2.2lb (1kg) 3mm Black ABS Filament 1kgBlackABS3 "

Holy crap.. it was ABS!!!!

This means.. all this time.. I thought my filament was PLA and treated it like PLA. I'm almost done with the entire spool, and I would not have even known this if it wasn't for that mystery sample filament???

However, I still wonder if this actually was PLA despite what the order summary indicates.

1. The printed objects using this black PLA is very shiny. A lot shinier than ABS objects I have.*
2. The printed objects are quite brittle. ABS objects, especially the white one, is quite soft.*
3. I was able to print at 180 C
4. When printing a small part, the print quality was really bad. I was looking forward to switching to ABS someday, because of a lot of curling and warping problems I had with a small part.

* I have a couple of objects I have printed with white ABS. Also, my extruder gears were printed with ABS (gray). So, I can compare the objects printed with my mystery black PLA:

But then, there are also evidences which tells otherwise:

1. The invoice summary says it's ABS (this would've been the end of the discussion - if I wasn't a type of person who constantly think other people always make mistakes)
2. I have been printing for quite a while without any fans.
3. I did a snap test and the filament requires a number of bending before it snaps*

*I actually was able to snap this black PLA filament easily, but that was because I bent the filament I pulled out from the extruder. When I tried to bend a fresh, unused part, yeah, it didn't snap.

So, basically, the only way that I can explain everything stated above is... it was ABS plastic indeed, but the pigment used for black color contributed to some of the characteristics which resemble those of PLA, even including lower melting temperature!

If that is the case... I first need to cut down my alcohol consumption; I need to save my brain cells (what's left of them). Also, until I become better with this 3D printing business, and resolve all the big and little issues, I should stick with one color, like neutral, to eliminate additional variables.

Man, I may need to change my user ID here, too. I don't think anybody will every believe anything I say.. LOL
Re: OMG, My PLA filament was actually ABS!
August 23, 2013 05:42PM
Quick test: If it dissolves in acetone, then it's ABS.
Re: OMG, My PLA filament was actually ABS!
August 24, 2013 12:29AM
Well Yam, that explains all your extruder issues. See if you can get that hot end up to 230 and the heat bed up to 110 and do some printing. I would reccomend you actually really order some pla though its much easier to print and doesn't warp so bad like abs. I reccomend glass cleaned with Isopropyl alcohol until it squeaks followed by three lightish coats of aquanet hair spray with ample dry time in between. Never had a pla part come unstuck using this procedure unless I wasnt meticulouss during glass prep. I wash hairspray off with hot running water between prints. You can try using it more than once, but I have gotten mixed results with reuse. It helps to have more than one sheet of glass so you can switch out and reprep one while printing on another.
Re: OMG, My PLA filament was actually ABS!
August 24, 2013 01:52AM
Yep, already ordered a spool of PLA and waiting for it to come.

I really liked the sample PLA that I have received. In my opinion, PLA printing is somewhat cleaner/neater than ABS printing. Also, I like the fact that I only need to heat up the bed to 60 C - heating the bed usually is step that takes the longest (well, second to the actual printing) so it's really nice I don't have wait for the bed to get all the way to 110 C.

I took Colin's advice from the get go; he also recommended using hair spray. I actually apply easy one coat to the plate, and I haven't had too much trouble keeping the objects stuck to the heated bed, unless it's a tall piece with small bottom. For those tall objects, yeah I put some extra hair spray and most of times that did the trick.

I just use Windex to clean up the glass - I'm just too lazy to bring my glass plate to the kitchen or bathroom to use soap and water. I just keep a role of paper towel and a bottle of Windex next to my printing station, and only use them to clean the glass. So far it's been working out alright.

I usually am able to use the glass plate without having to clean it and re-applying hair spray. I only clean it when it looks dirty (with all the marks/foot prints left by the previously printed objects). Sometimes I get really lazy and just spray a little bit of hair spray while the glass is still attached to the heated bed, and sometimes even when it's still hot. LOL I need to be very careful with my aim and make sure the hot end is out of the way though.
Re: OMG, My PLA filament was actually ABS!
August 24, 2013 03:57AM
I think that the variability that you get between different ABS filaments is quite large. All of my black 1.75mm filament was purchased as ABS but the printing smell varies a lot as does appearance, best extrusion temperature, stickiness to various beds etc.. All of the black ABS that I have used vapour polishes in acetone, some getting a grey appearance, others becoming very black indeed. As to disolving in acetone, I have a small bottle of acetone that I put 100mm of ABS filament into which, after a week, had turned milky with a black gloopy blob in the bottom while another sample disolved within minutes to an inky, viscous liquid.

Re: OMG, My PLA filament was actually ABS!
August 24, 2013 06:00AM
The differences between ABS and PLA are becoming blurred. I think Fabbersherry add plasticisers to their PLA so it is far less brittle than pure PLA is and bends and breaks more like ABS. Also pigments change the viscosity and hence the extrusion temperature (note this is not the same as the melting point).

Some people report ABS that does not dissolve in acetone.

I think the most reliable test is probably putting a sample in hot but not boiling water from a kettle. PLA goes very soft, like rubber above 60C.

Re: OMG, My PLA filament was actually ABS!
August 24, 2013 08:26AM
Yamster, my PCB headed bed takes like 40 min to get up to 110, which I don't like either. Disconnect it from the electronics and check the resistance across the ends of the bed's wire. Should turn out to be around 1.2 ohms. (If not check that you don't have a bad connection between the bed and the wire causing extra resistance.) If your like me your bed has a little higher resistance than that. The bed is suppose to be a 120 watt heater. More watts = more heat. We're suppose to be drawing 10 amps off the power supply, so 12v / 1.2ohms = 10 amps. That gives us our 120 watt (10 amps * 12v) heater. The higher the resistance of your bed and it's wire, the fewer watts your going to get and therefore less heat.

My bed is now about 10 mm off the hard board it use to be mounted to and has 100% wool felt below it. I also cover my bed with a piece of cardboard with some of the felt glued to the back of it during preheat. These two things reduced my preheat time by 40%.
Re: OMG, My PLA filament was actually ABS!
January 16, 2015 05:52PM
I had the same problem, ordered some black pla from amazon and when I got it didn't bother to read the box or anything and started trying to print with it like it was pla. I had nothing but jams and filament griniding and thought something was wrong with my printer. Lo and behold I go grab the original box I got it in and it turns out it's abs instead. Changed my temp settings and now it's printing great
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