Using Large-Scale Additive Manufacturing as a Bridge Manufacturing Process in Response to Shortages in Personal Protective Equipment during the COVID-19 Outbreak

Abstract

The global coronavirus disease (COVID)-19 pandemic has led to an international shortage of personal protective equipment (PPE), with traditional supply chains unable to cope with the significant demand leading to critical shortfalls. A number of open and crowdsourcing initiatives have sought to address this shortfall by producing equipment such as protective face shields using additive manufacturing techniques such as fused filament fabrication (FFF). This paper reports the process of designing and manufacturing protective face shields using large-scale additive manufacturing (LSAM) to produce the major thermoplastic components of the face shield. LSAM offers significant advantages over other additive manufacturing technologies in bridge manufacturing scenarios as a true transition between prototypes and mass production techniques such as injection molding. In the context of production of COVID-19 face shields, the ability to produce the optimized components in under 5 min compared to what would typically take 1 - 2 h using another additive manufacturing technologies meant that significant production volume could be achieved rapidly with minimal staffing.

Keywords: Additive manufacturing; Coronavirus; Coronavirus disease-19; Face shield; Personal protective equipment; Three-dimensional printing.

Figure 1

Typical components that make up an emergency face shield.

Figure 2

InVision Freehand schematic showing the design methodology employed in optimizing a design for large-scale additive manufacturing.

Figure 3

Initial design for face shield components produced using large-scale additive manufacturing, (A) showing the computer-aided design model, (B) the Simplify3D sliced print preview, and (C) the final printed part.

Figure 4

Improved face shield design using large-scale additive manufacturing, (A) showing the computer-aided design model, (B) the Simplify3D sliced print preview, and (C) the final printed part.

Figure 5

(A) Toolpath preview of parallel print process with travel moves shown in red, and photos showing a comparison of the quality of (B) multiple parts on a single build plate using parallel production strategy with defect areas highlighted and (C) multiple defects versus (D) toolpath preview of a sequential print process and photos of (E) multiple parts on a single build plate using sequential production strategy showing (F) minimal defects.

Figure 6

Mechanical testing results of the three-dimensional printed headbands.