PETG plastic claims to be a material strong like ABS and easy to print like PLA. I don’t print with ABS because it is toxic, so I’m very interested in other strong materials which can replace ABS.
I have ordered 2 rolls of PETG filament (from 2 different manufactures) and today I have received them.
I’m recording here my first experiments with this plastic on our 3D Printizer.
One roll is yellow and the other one is fully transparent. Both spools came in voided plastic bags (this could mean that PETG absorbs moisture (?) or maybe the manufacturers are just paying a lot of attention to details).
I have started with the transparent PETG filament one mainly because is more expensive (19USD instead of 12 for the yellow one). Lets hope that the transparent one is better.
The PETG filament is very clear, very transparent. It is soft like a flexible plastic.
I loaded it in the printer and I raised the nozzle head temperature to 200. When a reached that temperature I rotated the extruder gear manually … and the PETG plastic has started to come out very easy. This is a good sign … printing at lower temperatures is a good thing. I was also able to extrude at 195 C, but it was hard to push.
However, the manufacturer recommends a temperature of 220-250 C for the hotend … so I raised the temperature to 230. Other specifications for our hotend are: (custom) JHead with 0.4 mm nozzle for 1.75 mm filament. Layers have 0.25mm height and 0.45 mm thickness. These are the standard parameter that I use for PLA filament … for my first experiments with PETG I have not changed them.
I don’t know what temperature should I use for the print bead (the manufacturer has not mentioned that on their web-page) … so I started with no heated bed (with kapton tape on it) – room temperature (which is 20 C now). Verdict: PETG plastic does NOT stick to the cold bed (with kapton tape on it). Maybe it can stick on painter tape … I will test that later. EDIT: I have tested and PETG does NOT stick on blue painter tape (cold bed).
The strings of PETG plastic coming out from nozzle are flexible and very strong: even if I have stretched them several times … this flexibility is NOT possible with PLA.
Next step: I have raised the temperature of the bed to 65 degrees Celsius (this is the temperature that I use for PLA) and I hit Print again … this time the PETG plastic sticks to the bed. In the future I will investigate which is the minimal temperature that I can use for the heated bed so that the PETG will stick to it.
The first printed part was a very small one (a cylinder with 1 cm diameter with some wings inside). The part is not transparent (as I have expected from such a clean filament).
When done, I removed it from the heated bed. Very easily ! This means that (probably) it does not stick very well to the heated bed … so, maybe, if the parts warps, it will jump from the bed. More tests are required with larger pieces.
For PLA i cool the parts with 2 coolers … but I don’t know if they are required for PETG. For the second piece I have turned them off.
Now, the second part to print is my favorite one: the rocket glass … It has a larger base, so we can test if the material warps or not.
This time the speed is 30mm/s for loops and 75 mm/s for infill. The manufacture stated that one can use a similar speed with PLA. Infill was set to 25%
Here is a movie during print:
The part sticks very well to the heated bed … NO warping … and I was able to remove it easily from it even if the bed was still hot. With PLA I have to decrease the temperature of the bed below 50 C in order to remove pieces.
Below is another movie where I played with a calibration cube made from PETG.
Details about strengths will be given in the next post.
1. I have tested and PETG does NOT stick on blue painter tape (cold bed).
2. It does NOT stick to cold glass neither.