3D Printing Materials




Overview

Here you can find information about 3D printing materials that I have tried out or am interested in trying out in the near future. This Ultimaker Schooling article about materials provides an overview over the materials sold by Ultimaker and ColorFabb.

Quick Comparison
PLA ABS nGen PET-G XT CPE
glas transition temp. (°C) 50 105 85 75 75 100
long-term stable - +++ ++ +++ +++ +++
mechanically tough + +++ +  ? +++ +++
printing temp. (°C) 190 - 220 230 - 260 220 - 240 240 - 260 235-245 240 - 260
print bed temp (°C) 50-60 70-105 75-85  ? 70 100
easy to print +++ + +++ ++ + ++
odorless + - +++ ++ +++ +++
contains styrene - + -  ? - -
stable while printing + + +++ ++  ?  ?
objects have nice surface + - +++ ++ + -

PLA

Requires lower printing temperatures, warps less and does not smell as bad as ABS. On the other hand, it is less durable, sensitive to moisture, and becomes soft at relatively low temperatures (≈60°C).

ABS

Used to print physically durable objects. Has considerable downsides: Hazardous gases, micro-particles and strong unpleasant smell generated while printing, stronger tendency to warp while cooling down compared to PLA. I bought a spool from REC but haven't tried it yet.

ColorFabb_XT

Based on Eastman's Amphora AM1800 material. Requires a high nozzle temperature which shortens the lifespan of the teflon heatbreak in the print head. I have no experience printing with this copolyester material yet.

ColorFabb nGen

nGen is based on Eastman's Amphora AM3300 copolyester material. Objects printed with it have more flexibility and a much higher glass temperature than with PLA. AM3300 is not affected by moisture, which makes it easier to store opened filament spools. The light gray colored filament I am using produces a nice matt surface. Layer bonding strength can be worse than PLA when printed with 220° C nozzle temperature and print bed temperature at 75° C. Especially for thin-walled parts. Does not smell but still produces dizzying gases during printing.

So far, I printed low flat objects and had no problem with bed adherence when using a glue stick and opting for a brim with 10 lines. The thin layer of glue is also precautionary to prevent the bottom print layer from fusing with the glass bed (which I heard can happen with ColorFabb's XT). Although AM3300 is considered safe for food contact, I'm not sure whether ColorFabb's filament production process makes it unsafe in the end. Here is some printing advice from ColorFabb and here are the settings I use:

nozzle ⌀: 0.4 mm
color: light gray
nozzle ⌀: 0.25 mm
color: light gray
nozzle ⌀: 0.25 mm
color: black
nozzle ⌀: 0.80 mm
color: black
nozzle temperature (°C) 226 228-230 230-235 220-235
bed_temperature (°C) 80-85 80-85 80-85 75-85
layer height (mm) 0.1 - 0.2 0.06 - 0.2 0.06-0.2 0.06-0.2
print speed (mm/s) 40 22 22 40-60
minimum layer time (seconds) 4 4 4 4
fan_speed 40% 30% 30% 40-75%

nGen tends to stick to the nozzle. I guess that's why the recommended retraction distance is so large. The nozzle pulls strings from the top layer when retracting, which could mess up your print. Minimize the need for retraction by designing the object accordingly and by turning on combing (which makes the print head travel over already printed areas and avoid pulling strings over air gaps as much as possible). I'm seeing satisfactory results with a retraction distance (or "Z-hop") of 4.5 mm. A higher z hop (8 mm perhaps) may reduce stringing even more.
For larger objects you may need to change the nozzle temperature and fan speed at certain stages during the print. Low nozzle temperatures (< 228° C) and high fan speeds (> 60%) will make the material cool down faster and reduce stringing but also hinder the material from bonding well. If you see bumps forming that the nozzle fails to run over in the next pass you may need to increase the nozzle temperature and/or reduce the fan speed.

If there are thin walls in the structure the set the fill density to 100% so that the nozzle does not need to retract too often. If you decrease the print temperature less than circa 224° C to avoid stringing then you risk running into layer adhesion problems for the reasons mentioned above.

Because of this tendency to stick to the nozzle, you also need to watch out for problems when printing starts. The preliminary material, that flows out of the nozzle right before the print head moves to trace out the brim (or skirt), must not curl up toward the nozzle where it will stick and cause a mess at the printing position. Stand by with a tweezer in your hand to pull away the extruded string if it comes out curling.

When cleaning the nozzle with the atomic method I was able to pull out black nGen filament from a 0.4 mm nozzle with a satisfactory plop sound after cooling down the nozzle to 115° C and letting the filament sit in there for a minute before pulling it out swiftly.

Ultimaker CPE

CPE is a type of filament that is supposedly perfectly suited for complex, technical prints, a fairly stiff, strong and impact resistant type of filament. CPE is also claimed to be perfect for bridging large gaps. CPE needs to be printed on higher temperatures (between 230°C and 250°C) to get good results. This is why Ultimaker adds an extra PTFE coupler to each spool of CPE. I have no experience printing with this material yet but would like to try it for printing functional parts.

Where To Buy Filaments For Ultimaker Printers In Europe