With the Coronavirus pandemic, COVID-19, continuing to spread across the length and breadth of India, health agencies and hospitals are facing acute shortages of N95 masks. A number of big and small hospitals, testing labs and government agencies are showing interest in 3D printed face shields.
Rising up to the challenge posed by dearth of N95 masks and the growing demand for 3D printed face shields, Mumbai-based Boson Machines, a 3D printing firm, is making 3D printed face shields to be used by doctors treating COVID-19 patients in the country. Unlike N95 masks, which only cover your nose and mouth, face shields are attached to the wearer’s head and have a transparent PVC film that covers most of the user’s face and even ears. However, these shields are not a replacement for regular masks recommended by doctors but act as an extra layer.
Commonly referred to as additive manufacturing, 3D printing creates three-dimensional parts from computer-aided design (CAD) models by successively adding material layer by layer until the physical object is created. Both metal and plastic products can be made with a single machine without any kind of tooling.
The frame of the 3D face shield is made out from PLA (polylactic acid), one of the most popularly available raw materials for 3D printing, which cannot be sterilised like the visor. However, according to Boson Machines they can sterilise the frame by using 70% rubbing alcohol, soaking them in a 30% KOH solution followed by a round in ethylene oxide (EO) gas oven designed specifically for sterilising plastic medical equipment. The mask, made of PVC, is designed to cover the face, earlobes and extend beyond the chin and up to the chest. This is to provide extra protection to the user. The 3D face shields are now being used only for one patient after which the doctors discard them though the front visor can also be sterilised using autoclaving.
The utility of face shields is high considering that an N95 mask covers the nose, mouth and chin, with large parts of the face uncovered.
The advantage of 3D printing is that one person can handle 20 machines at the same time and each machine can print a product overnight without monitoring. Each shield takes about 90 minutes to print and costs between Rs 150 and Rs 200 depending on the design — there are variations, including one that is enclosed from the top.