If you’ve 3d printed with abrasive filament, or simply used a nozzle for a while you may have noticed that over time 3d printer nozzles wear out. Every 3D printing material causes wear, some more, some less. Today we are going to take a look at what causes nozzle wear, its symptoms and how to detect it and finally we are going to talk about how to prevent 3d printer nozzle wear.
What causes 3d printer nozzle wear?
Nozzle wear is mainly caused by particles and pigments in your filaments, which are hard and have an abrasive surface. Over time they will work like sandpaper and wear out your printer nozzles.
These pigments are what gives your filament the colour it has. Most notably white filament will wear out your nozzles fast because it contains titanium dioxide. It’s a pigment which gives a nice bright white colour, but the material it’s made out is really hard and abrasive. Another good example is glow in the dark filament. In order to glow it contains strontium aluminate, a material which can cause in some cases excessive nozzle wear as shows a post from this reddit user.
Another cause of wear are deliberately added particles. A notorious case is carbon fibre infused filament. But also metal or wood infused filament can cause accelerated wear and clogs.
what are the symptoms of nozzle wear?
Here is a short list of the most important types of nozzle wear:
The nozzle diameter has increased
The inner diameter and the tips surface shows scratches and grooves
The tip of the nozzle becomes shorter
The geometry of the nozzle becomes rounder
The symptoms on the 3d printed part are generally reduced print quality, Increased stringing and under extrusion. Certain people think that the ridges also increase the chance of clogging, but we couldn’t prove this in our tests. Nevertheless our results showed increased colour and material contamination, because the ridges can house filament residues.
How to detect nozzle wear?
The best way to see that your nozzle is worn out is generally decreased quality of the 3d prints. Another indicator can be the increase in the distance between your nozzle and the print bed.
Another indicator you can look for is a sharp bend in the extruded filament right after it exits the nozzle. In order to test that you can simply heat up your nozzle and extrude some filament. It should go straight down. But if it takes a sharp bend in one direction, that can mean your nozzle is worn out. If you also see a reduction in print quality you should probably change your nozzle.
How to prevent nozzle wear?
A worn nozzle can be really annoying. It causes a reduction in 3d print quality and other problems. Some nozzles can be better at wear resistance which makes them last longer.
A nozzle is generally better suited for printing with abrasive materials and generally wears out less if it is either made in a harder material and/or has a hard and wear resistant coating on it. Another factor that benefits wear resistance is a better optimised inner geometry, reducing wear on sharp edges.
There are 2 really common types of nozzle materials: standard brass nozzles and their hardened steel counterparts. The third option is the Titan nozzle, made by our company: Imark Industries. Our nozzle choice opinion may be influenced because we included our nozzle, but we provided raw scientific data with sources in the table below, so you can make your own choice.
You may think the hardened steel nozzle is the best choice for abrasive materials, but there are some important trade offs to consider. The Hardest nozzle isn’t necessarily the best nozzle. Hardened steel nozzles may be much harder than brass nozzles, but their thermal conductivity is a lot worse. Lower thermal conductivity significantly reduces the heat transfer from the heater block to the plastic, thus reducing the temperature of the material when exiting the nozzle. This can cause layer delamination and requires much more force to extrude, possibly causing step skipping of the extruder motor or grinding of the filament and under extrusion.
In order to provide the ideal solution to nozzle wear and clogging problems, we created the Titan nozzle. It’s made out of a unique titanium molybdenum alloy, providing good hardness and an excellent thermal conductivity. In addition to that we gave it a coating, reducing friction and material adhesion while improving wear resistance.
In addition to that we gave it our advanced flow geometry, which further improves material flow and reduces internal wear.
conclusion
A nozzle wears out due to hard and abrasive particles and pigments in the filament. It augments the diameter of the hole while shortening the nozzle. This causes an overall reduced print quality. The best way to prevent it is by using better suited nozzles while printing abrasive filaments or large quantities.
