What is the controlled temperature for thermoplastic extrusion in FDM?

The controlled temperature for thermoplastic extrusion in Fused Deposition Modelling (FDM) is set to be slightly above the solidification temperature of the material. This allows the thermoplastic to become pliable and suitable for extrusion, ensuring that it flows smoothly through the nozzle. By maintaining a temperature that is 0.5 degrees Celsius above its solidification temperature, the material can achieve an optimal viscosity for deposition without overheating, which could lead to degradation or uneven extrusion.

Operating at or below the melting point is not optimal since that could lead to excessive thermal degradation of the plastic, while a temperature significantly above the necessary range might result in inconsistencies in the material's quality and mechanical properties. Room temperature is insufficient for thermoplastic extrusion as it does not permit the material to flow properly for printing. Thus, being very close to, but slightly above the solidification temperature strikes the right balance for effective and reliable 3D printing with thermoplastics.