STRINGING OR OOZING v2

4. STRINGING OR OOZING

Stringing or oozing is also a common problem in 3D printing. This problem, again, can be easily eliminated through extensive trial and error techniques. To resolve this issue, users must understand the term ‘Retraction’.

Retraction is the backward movement of the filament to prevent excess oozing of the malted material. By carefully managing this parameter, oozing or stringing problems can be eliminated.

In the case of the slicing software settings, you can only control two parameters, namely the Retraction speed and distance. We will look at other issues as well to control this problem.

Check out the following 3D printing troubleshooting tips to know how to resolve the stringing problem in 3D printing.

• Set Ideal Retraction Speed

If the problem of stringing is faced by users then the first parameter to be checked is the retraction speed. This parameter controls the speed at which the filament is pulled back. If the speed is too fast then the melted plastic may break away from the unmelted filament above and the whole purpose of retraction is lost. If the speed is slow, then it may not help in reducing the oozing.

So, the general solution is to design a model with subsequent towers at suitable distances and then try adjusting the parameters to check the stringing effect. By carefully controlling the speed, an ideal value may be found out. All slicing software have retraction settings to control the retraction speed. 

• Set Ideal Retraction Distance

Retraction distance is distance by which the filament is pulled back. The retraction distance will depend on the extrusion system, direct-drive or Bowden-drive. The direct-drive extruders will work with small retraction distances (generally around 1-2mm) while the Bowden extruder system will require retraction distance of around 5-10mm.  This distance will also depend on the type of material and the printer used, and so the distance will have to be carefully found out for optimum printing.

By carefully controlling the distance through a trial and error method, an ideal value may be found out. All slicing software have retraction settings to control the retraction distance. 

• Adjust Heater Temperature

Oozing and stringing can also be affected by the printing temperature. If the temperature is too high then the viscosity of the material is lowered and the material drips even when the filament is retracted. A low temperature will stop the oozing but will affect the print quality. So, consider this parameter when setting an ideal print temperature.

• Avoid Long Free Travels

By getting inside the skin of the slicer settings users can work with settings which also controls the free movement of the nozzle. These settings help in finding the shortest route to the next deposition point or the travel movements can be controlled to avoid crossing an open space altogether. This eliminates the possibility of creating strings.

• Adjust Travel Speed

As explained above, by reducing the travel, the stringing can be reduced. And so by increasing the travel speed of the nozzle, the oozing can be minimised. So, if the printer is able to handle fast travel movements then a higher travel speed will help minimise the stringing or oozing.