TY - JOUR
T1 - Calibration Dependencies and Accuracy Assessment of a Silicone Rubber 3D Printer
AU - Jaksa, Laszlo
AU - Pahr, Dieter
AU - Kronreif, Gernot
AU - Lorenz, Andrea
N1 - Funding Information:
Funding: This work was supported by the Provincial Government of Lower Austria (Land Nieder-österreich) under grant assignment number WST3-F2-528983/005-2018. This work has also been supported by ACMIT (Austrian Center for Medical Innovation and Technology), which is funded within the scope of the COMET (Competence Centers for Excellent Technologies) program and by the federal government (BMDW and BMK) and the governments of Lower Austria and Tyrol.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/6
Y1 - 2022/6
N2 - Silicone rubbers are relatively new in additive manufacturing, with only a few commercial printing services and reports on custom-built printers available. Publications and standards on calibration and accuracy assessment are especially lacking. In this study, the printhead calibration process of a custom-built silicone printer is explained, and a set of test objects isproposed and evaluated. The printer in use is based on an open-source filament printer, capable of multi-material printing with silicone rubbers and thermoplastic polymers. Three different high-viscosity single-component liquid silicone rubbers and one polylactic acid thermoplastic filament were used as printing mate-rials. First, the calibration process of the silicone printhead was conducted, and the dependency of the dosing accuracy on silicone viscosity, nozzle diameter and extrusion speed was evaluated. Sec-ond, various test specimens were proposed and printed to characterize the accuracy and geometric limitations of this printer. These test parts contained features such as thin walls, slender towers, small holes and slots, unsupported overhangs and bridges. It was concluded that silicone viscosity strongly affects geometric inaccuracies. Design recommendations were deducted from the results, advising for wall thicknesses above 1 mm, slenderness ratios below 2, bridging lengths below 2 mm and unsupported overhang angles below 30°.
AB - Silicone rubbers are relatively new in additive manufacturing, with only a few commercial printing services and reports on custom-built printers available. Publications and standards on calibration and accuracy assessment are especially lacking. In this study, the printhead calibration process of a custom-built silicone printer is explained, and a set of test objects isproposed and evaluated. The printer in use is based on an open-source filament printer, capable of multi-material printing with silicone rubbers and thermoplastic polymers. Three different high-viscosity single-component liquid silicone rubbers and one polylactic acid thermoplastic filament were used as printing mate-rials. First, the calibration process of the silicone printhead was conducted, and the dependency of the dosing accuracy on silicone viscosity, nozzle diameter and extrusion speed was evaluated. Sec-ond, various test specimens were proposed and printed to characterize the accuracy and geometric limitations of this printer. These test parts contained features such as thin walls, slender towers, small holes and slots, unsupported overhangs and bridges. It was concluded that silicone viscosity strongly affects geometric inaccuracies. Design recommendations were deducted from the results, advising for wall thicknesses above 1 mm, slenderness ratios below 2, bridging lengths below 2 mm and unsupported overhang angles below 30°.
KW - 3D printing
KW - additive manufacturing
KW - calibration
KW - silicone rubber
KW - test geometry
KW - viscosity
UR - http://www.scopus.com/inward/record.url?scp=85128753942&partnerID=8YFLogxK
U2 - 10.3390/inventions7020035
DO - 10.3390/inventions7020035
M3 - Journal article
AN - SCOPUS:85128753942
SN - 2411-5134
VL - 7
JO - Inventions
JF - Inventions
IS - 2
M1 - 35
ER -