TL:DR What are the pros and cons of PETG when compared to PLA?

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(Kevin Danger Powers) #1

TL:DR What are the pros and cons of PETG when compared to PLA?

So since I’ve started printing I’ve only ever used PLA. It’s cheap, works pretty well and requires lower temps. However I’ve read lots of good things about PETG as well but I just don’t know if I want to actually get any or not. I have an Ender 3 printer so it has a heated bed. I generally print stupid stuff that doesn’t need to be super precise but the closer the better. I usually print on glass without any kind of added adhesive as well. So what are some pros and cons between the two filaments? Also, I don’t really want to try any other kinds of material just because I just don’t print that much and the material will likely go bad before I can use it all. So please just stick with the 2 for now. If you need any more info, just tag me and I’ll respond with an answer. Thanks in advance for any and all advice/information.

(Ulrich Baer) #2

if you want nice looking - stay with PLA. PET-G is only if you need strength and flexibility. PET-G is more viscose not that fluid like PLA so it is more likely to cause strings. Also it will not get soft from sunshine like PLA does. You have very low termal stress (expansion - no wraping) and a very good layeradhesion.

(Diane Attaway) #3

Try printing everything you do now in PETG and you’ll be running back to PLA. PETG is nice for some things, but it’s rather undomesticated…

(Christoph Pech) #4

PLA needs part cooling. Especially in high extrusion rate situations it’s hard to cool down overhangs fast enough. PETG doesn’t need much cooling.

(Daniel Bull) #5

In general PETG is slightly more food safe than PLA but check on the filament first. Both are better than ABS which definitely isnt food safe.

(Lars Clausen) #6

From the brief test I did, I found PETG as easy to print with as PLA, but inferior on overhangs. Interesting about it holding up to sunlight better, I have just the test subject for that.

(George Novtekov) #7

From the moment I found PETG i stoped using PLA. PLA is only used when I do figure or toy for my kid. Every mechanical part I do is from PETG or Polymaker PC Plus. So I print in this order PETG, PLA, PC Max.

(Jeff DeMaagd) #8

@Ulrich_Baer eh I get nicer looking prints with PETG, you can’t necessarily go as fast. Translucent PETGs can look shimmering. That said there’s plenty of grades so it’s worth trying different brands. It is a bit more oozy but that might be absorbed moisture too.

(Ulrich Baer) #9

@Jeff_DeMaagd if you print things with lots of travel moves then PLA looks better. Also velocity printing is not working with PET-G afaik. This doesn’t mean that PET-G couldn’t look nice but you will not get optical better results. And as there are also translucent PLA there is no advantage in using PET-G for optical reasons.

(Jeff DeMaagd) #10
(Jeff DeMaagd) #11
(Jeff DeMaagd) #12

I’ve tried Ingeo 3D8x0 based plastics. They’re nice but they just don’t match the optical clarity.

(Cameron Spiller) #13

PETG is heaps stronger than PLA, and more flexible.

Layer adhesion on Petg is crazy. I find parts break following the infill shape rather than delaminating.

I also found initial setup very unforgiving with PETG. Once it’s dialed in, it’s the bomb, but getting a good first layer is critical. If first layer isnt really nice, and complete, the print will likely be in trouble later.

Where a part made from PLA is brittle and snaps, PETG will bend and flex first.

Get a bit and try it.
https://profiles.google.com/photos/116055096952392900151/albums/6601664787875589345/6601664785557907890

(Cameron Spiller) #14

@Jeff_DeMaagd wow!! That’s nuts!!

(Neil Darlow) #15

I like the Dutch Filaments PET-G sold by 3dfilaprint in the UK under their own branding.

It’s modified over typical PET-G to print between 190C and 220C and it doesn’t absorb moisture like others.

I print it much like PLA with slightly more retraction distance and no forced cooling.

(Diane Attaway) #16

I made a bunch of Legos with PETG and the hardness made it great for that. Not as fine detailed as PLA, but very springy and snapped together well.

(Ray Tice) #17

PETG is very moisture sensitive, and prints much better dry. I had to bump up width on the first layer to get adhesion, as PETG is gummier when hot. Also, I’ve heard PETG is hard to remove from PEI. PETG is harder than ABS and less brittle than PLA, so I use it a lot.

(Ray Tice) #18

@Ulrich_Baer I find printing PET-G fast yields a dull finish, and slow it’s shiny, so I just assumed velocity painting would have an effect with it. I’ll have to try it. I’ve only used Inland brand PET-G, so that may be the difference.

(Kevin Danger Powers) #19

Sounds like I’ll probably just stick with PLA for now. Maybe if I have a specific project for it I’ll try something else but like I stated before, I don’t print a ton and it’s never anything critical. Thanks for all the responses though. Definitely gives me a better idea on what to expect from PETG.

(Kent Asplund) #20

@Cameron_Spiller My experience is that PLA (Esun PLA+) is WAY more impact resistant than PETG (Esun PETG). A friend got the same result on another brand of PETG.

So standard PLA versus standard PETG is like you say but there are different varieties, at least on the PLA side.

On paper Esun PETG has better performance than Esun PLA+ but in practice not so much. We had the experience that it was like standard PLA as it exploded on impact.

We are printing cars for competition in R/C and there the impact strength is crucial. Some components needs to be heat resistant ( 70 centigrades ) and we were hoping that PETG would be the golden bullet. Unfortunately it was to bad. We now use nylon but it is tricky to print