Pressure monitoring inside the nozzle of a fused filament fabrication (FFF) 3D printer

Pressure monitoring inside the nozzle of a fused filament fabrication (FFF) 3D printer

de Vries, Sietse (TU Delft Mechanical, Maritime and Materials Engineering)

Ayas, C. (mentor)
Fanzio, P. (graduation committee)
Accardo, A. (graduation committee)

Delft University of Technology

Mechanical Engineering | High-Tech Engineering

2022-12-16

Fused filament fabrication (FFF) is the most used additive manufacturing technique that uses a heated nozzle to melt a polymer and a feeder to extrude it on a buildplate. The dependencies of temperature, shear-rate, viscosity and pressure of the melt create complex dynamics within the nozzle, which causes inconsistent extrusion. To improve extrusion control, a better understanding of the dynamics within the nozzle is required. The greatest knowledge gap comes from a lack of experimental data on the pressure inside the nozzle, due to the challenging environment for sensors. This study presents a novel way of monitoring the pressure inside the nozzle of an FFF 3D printer. A pin that is in direct contact with the melt transfers the force applied by the melt through a hole in the nozzle to an externally mounted load cell. The set-up has proven to provide reliable, repeatable pressure data in steady-state, static extrusion. The experimental data on different nozzle geometries and materials, with different flows and temperatures, has been compared to theoretical pressure calculations to identify non-linearities that influence the pressure such as entrance effects, temperature non-uniformity and viscoelastic behaviour of the melt. The proposed design can be used to gain more knowledge on the extrusion process to further develop extrusion control.

Pressure
3D printing
Fused filament fabrication
Nozzle
Monitoring

http://resolver.tudelft.nl/uuid:34aa6b4c-7b5c-4e93-be9d-e88a8598bf6f

Student theses

master thesis

© 2022 Sietse de Vries