How to print Neo TPU?
Our client parameters: printing temps: 220 degrees, retraction: 1.5
Due to the type of extruder in the machine, the filament retraction is excessive, which causes continuous jamming regardless of the temperature.
There are parameters to control these retractions and perform them only when strictly necessary, in our case, we use retractions of 0.5 mm and exclusively when the extruder movements are greater than 20 mm. It ́s necessary to understand that this filament is almost pure TPU without additives; nowadays, almost every TPU has lubricants and other additives to improve their printing.
On the other hand, the printing speed directly influences the printing temperature. A TPU such as Covestro’s (the main polymer without our nanofibers additive) needs low speeds and relatively low temperatures. The right extruder for TPU should have a nozzle longer than usual, there are several models on the market for this purpose, we can help you if needed.
To have good printing it is necessary to dry the filament since water absorption is an important factor (in addition to storing the filament in the airtight bag).
Finally, it is important to purge the machine well, if harder filaments such as ABS are used with the same machine because due to the low viscosity of the TPU, it cannot eject it through the nozzle. When this happens, it is normal to have to increase the melt temperature to be able to print and allow the material to flow, on the other hand, you are degrading the TPU.