TY - JOUR
T1 - Relating print velocity and extrusion characteristics of 3D-printable cementitious binders
T2 - Implications towards testing methods
AU - Nair, Sooraj
AU - Panda, Subhashree
AU - Tripathi, Avinaya
AU - Neithalath, Narayanan
N1 - Publisher Copyright:
© 2021
PY - 2021/10
Y1 - 2021/10
N2 - This study aims to relate print velocity to critical parameters extracted from a controlled ram extrusion test, towards a test method to expedite the selection of materials and process parameters for 3D-printing of cementitious materials. Higher print velocities, while aiding faster construction, results in a need for higher extrusion pressure, while lower velocities interfere with extrudate quality through effects such as water filtration. Steady-state pressures and dead-zone lengths corresponding to a chosen barrel-die geometry and print velocity are extracted from extrusion force-ram displacement relationships. The steady state pressure increases with print velocity, while the dead-zone length decreases. The deposition pressure between the nozzle exit and the print bed increases with increase in print velocity, and is proportional to the extrusion pressure. These results are used to define a range of desirable print velocities for the chosen geometry and the printer system, so that the extrusion pressure and dead-zone lengths are simultaneously optimized. The lower limit of the print velocity range, steady-state pressure, and dead-zone lengths are all lower when the material microstructural parameter (ratio of particle volume fraction to square of mean size) is higher, indicating the importance of appropriate material design in ensuring efficient 3D printing of cementitious binders.
AB - This study aims to relate print velocity to critical parameters extracted from a controlled ram extrusion test, towards a test method to expedite the selection of materials and process parameters for 3D-printing of cementitious materials. Higher print velocities, while aiding faster construction, results in a need for higher extrusion pressure, while lower velocities interfere with extrudate quality through effects such as water filtration. Steady-state pressures and dead-zone lengths corresponding to a chosen barrel-die geometry and print velocity are extracted from extrusion force-ram displacement relationships. The steady state pressure increases with print velocity, while the dead-zone length decreases. The deposition pressure between the nozzle exit and the print bed increases with increase in print velocity, and is proportional to the extrusion pressure. These results are used to define a range of desirable print velocities for the chosen geometry and the printer system, so that the extrusion pressure and dead-zone lengths are simultaneously optimized. The lower limit of the print velocity range, steady-state pressure, and dead-zone lengths are all lower when the material microstructural parameter (ratio of particle volume fraction to square of mean size) is higher, indicating the importance of appropriate material design in ensuring efficient 3D printing of cementitious binders.
KW - 3D printing
KW - Cements
KW - Extrusion
KW - Print velocity
KW - Steady-state pressure
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U2 - 10.1016/j.addma.2021.102127
DO - 10.1016/j.addma.2021.102127
M3 - Article
AN - SCOPUS:85108633222
SN - 2214-8604
VL - 46
JO - Additive Manufacturing
JF - Additive Manufacturing
M1 - 102127
ER -