How to recognize PLA from ABS ???

[italianmaxx 0]

I bought 2 rolls of PLA (?) from an italian source on ebay. everything went fine but now I'm trying it and I can smell something different in the air, somethind like a lightly sweet smell. my usual PLA (from ultimaker or faberdashery) never smelled like this.

I'm printing an 'old' PLA gcode and I didn't change temperature or other. first lyer seems stictching well on usual cold bed with tape, but...

can someone tell me a way to recognize PLA from ABS ? :?:

 

thanks!

[armstrom 0]

PLA often smells sweet when you are printing with it. If you were printing with ABS it would smell, but it wouldn't be sweet Green PLA smells like pancake syrup to me.

-Matt

[italianmaxx 0]

my first print with this new filament ended right now.

I can see just a little warping on the corner (the piece is 5cm x 8 cm, x 0,8cm)

tha filament is a yellow translucent, not bad but nothing more than ok.

the piece stiched well to the cold bed and finished without a problem.

the filament is just a bit oval (2,9 x 2,75) but quite costant. printed at 210 C.

[Daid 303]

If you printed it at 210C then it's not ABS. Also, ABS gives off toxic fumes, while PLA fumes are harmless. And, if I got it right, ABS should be a bit more flexible then PLA. And ABS loses 15% of it's volume after heating, so you would be extruding to little material then.

[italianmaxx 0]

Thanks, it's a great thing so!

I bought 2 kg of this stuff (yellow translucent and natural) for 40 euros and at this moment, after 2 pieces printed it seems a good buy.

printed a quadricopter motor mount too (from thingiverse hugin) and it's really cool and hard.

by the way, as usual cura and printrun make their duty sooo well!

[IRobertI 514]

To test it without printing you can simply start bending it sharply at random points. PLA will snap, ABS will not.

[italianmaxx 0]

The results with the new filamnet and the temp of extrusion are a good sign PLA but the SNAP test is going to give me the ultimate answer. thanks!

[ian 32]

can you share your new PLA source ? (seller)

Thanks.

Ian

[italianmaxx 0]

It is an italian seller on ebay. 800gr at 16 euro. No rolls, filament seems a bit oval but have good viscosity and it is very tenacious after printed. Very vey few little bubbles inside. I m happy

You can find it on ebay searching for 'pla 3mm filament' he lives in catania, sicily.

I heard from another friend that he bouht a fantastic filament from filamentprint. He is really happy, i will try it in the future.

[frodeheg 0]

To test it without printing you can simply start bending it sharply at random points. PLA will snap, ABS will not.

The "ABS fix kit" that followed with the Ultimaker snapped very easily when my 3 year old kid wanted to take a look at what I had lying around my Ultimaker. So ABS does snap easilly, or my 3 year old is stronger than you :lol: Just kidding :-) ...you probably have a better quality batch ;-)

[IRobertI 514]

Not sure what the "ABS fix kit" is but I'm not surprised the wee one managed to break it. Kids are incredible that way, they will find the point of failure faster than any engineer ever could.

Also, I might've been a bit unclear what I meant with what I said earlier. I was speaking more in terms of mode of failure. Generally when you bend ABS to the breaking point it'll bend but still stay together. PLA on the other hand tends to fail by snapping apart. In other words PLA tends to be harder than ABS.

Of course we all know that different brands/colours/etc behave a bit differently but oh well. Here's a couple of vids that show what I mean:

 

 

 

[frodeheg 0]

The "ABS fix kit" is just a short piece (1 m) of ABS intended to be extruded for the purpose of stopping any leakage from the nozzle. If you use nothing but PLA on the Ultimaker it will most likely leak a lot.

 

Also, I might've been a bit unclear what I meant with what I said earlier. I was speaking more in terms of mode of failure. Generally when you bend ABS to the breaking point it'll bend but still stay together. PLA on the other hand tends to fail by snapping apart. In other words PLA tends to be harder than ABS.

 

Yes, agreed :-)

[IRobertI 514]

Ah ok, I guess that's something they've added to later kits as that was not included in mine.

[futurejames 0]

The "ABS fix kit" is just a short piece (1 m) of ABS intended to be extruded for the purpose of stopping any leakage from the nozzle. If you use nothing but PLA on the Ultimaker it will most likely leak a lot.

Leak how? I had the kit but didn't use it, and I only extrude PLA. Is there something I should be watching for? Or should I just extrude the ABS now?

[joergen 2]

The "ABS fix kit" is just a short piece (1 m) of ABS intended to be extruded for the purpose of stopping any leakage from the nozzle. If you use nothing but PLA on the Ultimaker it will most likely leak a lot.

Leak how? I had the kit but didn't use it, and I only extrude PLA. Is there something I should be watching for? Or should I just extrude the ABS now?

The "leak is the dreaded PLA plug that forms when there is a gap between the bowden and the brass tube, and the PLA can bond with the PEEK. printing some ABS while that section is still free of any PLA helps to seal it off, at least temporarily.

[frodeheg 0]

I did not have a problem with any leakage between the bowden and the brass tube, my leakage was PLA flowing on the outside of the nozzle dripping on to the print and ruining it. Extruding the ABS stopped that leakage; but I guess the ABS stops any leakage no matter where it is due to its viscosity and higher melting point...

[reprapfilament 0]

To test it without printing you can simply start bending it sharply at random points. PLA will snap, ABS will not.

I printing with a source of PLA, bending not break,it is a modify formulation that can improve toughness..some time, you can bend the ABS some times on different direction, ABS will be break.

I also have one method to recognize,

(1)PLA soft temperation is 60 deg, ABS will be up to 120 deg, so you can dip the filamnet to hot water(when the temperature you can't stand is more than 60 deg), the soft one is PLA.

(2)PLA is very ver hard, but ABS is not that hard, you can bite the filament, the real PLA can't easily left teeth path, but ABS easily.