Open source high-temperature RepRap for 3-D printing heat-sterilizable PPE and other applications

Noah G Skrzypczak; Nagendra G Tanikella; Joshua M Pearce

doi:10.1016/j.ohx.2020.e00130

Open source high-temperature RepRap for 3-D printing heat-sterilizable PPE and other applications

HardwareX. 2020 Oct:8:e00130. doi: 10.1016/j.ohx.2020.e00130. Epub 2020 Jul 30.

Authors

Noah G Skrzypczak¹, Nagendra G Tanikella², Joshua M Pearce^{2

3

4

5}

Affiliations

¹ Mechanical Engineering - Engineering Mechanics, Michigan Technological University, USA.
² Department of Materials Science & Engineering, Michigan Technological University, USA.
³ Department of Electrical & Computer Engineering, Michigan Technological University, USA.
⁴ Équipe de Recherche sur les Processus Innovatifs (ERPI), Université de Lorraine, France.
⁵ School of Electrical Engineering, Aalto University, Finland.

Abstract

Thermal sterilization is generally avoided for 3-D printed components because of the relatively low deformation temperatures for common thermoplastics used for material extrusion-based additive manufacturing. 3-D printing materials required for high-temperature heat sterilizable components for COVID-19 and other applications demands 3-D printers with heated beds, hot ends that can reach higher temperatures than polytetrafluoroethylene (PTFE) hot ends and heated chambers to avoid part warping and delamination. There are several high temperature printers on the market, but their high costs make them inaccessible for full home-based distributed manufacturing required during pandemic lockdowns. To allow for all these requirements to be met for under $1000, the Cerberus - an open source three-headed self-replicating rapid prototyper (RepRap) was designed and tested with the following capabilities: i) 200 °C-capable heated bed, ii) 500 °C-capable hot end, iii) isolated heated chamber with 1 kW space heater core and iv) mains voltage chamber and bed heating for rapid start. The Cereberus successfully prints polyetherketoneketone (PEKK) and polyetherimide (PEI, ULTEM) with tensile strengths of 77.5 and 80.5 MPa, respectively. As a case study, open source face masks were 3-D printed in PEKK and shown not to warp upon widely home-accessible oven-based sterilization.

Keywords: 3-D printing; Additive manufacturing; COVID-19; High temperature 3-D printing; Medical hardware; Open hardware; Open source; Open source medical hardware; Polycarbonate; RepRap; ULTEM.