5 Ways to Prevent Stringing in 3D Printing

Stringing occurs when small strings of plastic are left behind on a 3D printed model. This is typically due to plastic oozing out of the nozzle while the extruder is moving to a new location. To overcome this issue there are several solutions that might be helpful.

#1 Enable Retraction

Mostly enabling retraction can be the solution to the stringing problem. When retraction is enabled, the extruder will pull back the filament throughout an empty space. This prevents the molten plastic from trailing behind as the extruder moves. Once the extruder arrives at the next point the filament is pushed back again, and printing resumes.

In most slicing softwares, like Cura, retraction is usually enabled by default. However, it’s better to confirm that this is true, especially when you start experiencing stringing.

To enable retraction in Cura, do the following:

1. Open Cura, and click on print setting
2. Click on "Custom"
   
3. Search for "Enable Retraction".
4. Make sure retraction is enabled
   .
    

#2 Set the Right Temperature

The next most common cause for stringing is the extruder temperature. If the temperature is too high, the printing material becomes more liquefied and is more likely to leak out of the nozzle. However, the temperature should not be too low, otherwise, the filament could not melt enough, which can cause issues with extrusion.

If after enabling retraction you still face stringing problem, try decreasing your extruder temperature by 5-10 degrees increments, but do not reduce the temperature below the manufacturer’s minimum specifications. 

The recommended temperatures for common filaments are listed below:
PLA: 180-220 °C
ABS: 200-250 °C
PET: 215-235 °C
TPE: 210-240 °C
TPU: 230-250 °C

If you want to identify the ideal temperature for your printing material you can use a temperature calibration tower test print, see this tutorial to learn more.

#3 Adjust the Travel Speed

The travel speed can also affect 3D printer stringing. If your nozzle takes too long to move between two points, stringing is likely to occur because molten plastic has more time to ooze out of the nozzle. But if the extruder can travel faster, the short moves may be quick enough that the filament will not have enough time to ooze.

Increasing the travel speed of the nozzle when it’s not trying to print can reduce 3D printer stringing, Generally, a speed of 150 to 200 mm/s will work fine with most printing materials.

To adjust the travel speed in Cura, do the following:
1. Open Cura, and click on print setting
2. Click on "Custom"
3. Search for "Travel Speed"
4. Adjust the value of travel speed

#4 Clean the Nozzle

When you use a printer for a long time, the filament can leave a thin layer of residue in the nozzle. This thin layer can cause 3D printer stringing as filament strands will try to stick to the surface of your printed part.

To avoid such problem, make sure your nozzle is completely cleaned before any printing to remove any dirt from the previous filaments, you can use a Copper Wire Brush to clean your nozzle, check this video for more guidance.

#5 Keep Filaments Moisture-Free

Storing your filament in a moisture-free environment is an important factor to have good quality 3D prints without stringing. The moisture can increase the probability of oozing during extruder travel movements.

Therefore, you should store your filament in a moisture-free environment, you can consider a filament dryer to keep your filament always dry, especially if you live in a humid environment.

Resources:

• Stringing or Oozing
• 3D Printer Stringing: 5 Simple Solutions