Creating exponentially scalable PPE manufacturing alternatives leveraging additive manufacturing amidst a pandemic causing supply chain disruptions.

With the thought process of a mask being nothing more than packaging for one's face I looked to manufacturing methods used in that field for mass production.  Vacuum forming seemed like the perfect tool to combat PPE supply shortages - fighting exponential growth of the virus with an exponentially scalable manufacturing processes - something that additive manufacturing in-and-of-itself lacks.  

As often goes additive manufacturing is not always the end-all-be-all solution but it is an excellent solution to get there quicker, faster, and cheaper.  Our 3D Systems ProJet 660 binder jetting system was the perfect fit for the task.  Building at blistering speeds of up to 1 inch an hour with a build envelope large enough to accommodate multiple vacuum form tools per cycle we were able to rapidly develop and begin testing of a scalable, economical, means of PPE based on the Montana Mask developed by The Billings Clinic.  The process is also well fit to withstand the rigors of vacuum form tool usage, being 100% dense with good thermal resistance.  

Our early testing showed that TPU processed via fused deposition was creating a good seal, had methods to be sanitized for re-use, and was comfortable.  This left the challenge of replicating these results in a manufacturing process better suited to the quantities and price points needed for a successful stop-gap while traditional PPE supply chains stabilized.  It was about this stage in the project where demand started to dwindle as cases dropped - let’s hope this remains true.  We did get a few samples produced in a tupperware like material that had many characteristics that we liked about the additive TPU but lacked the comfort and did not seal nearly as well.  This material was readily available in comparison to sheet stock TPU.  

The next steps should this process become necessary again would be to source material that we know based on prior testing will work flawlessly and to ramp up production of traditional (metal) tooling to withstand more sustained production runs.  An additional benefit of ramping up tooling would be to automate the post-processing - for example die cutting of the filter insert hole.  The potential benefits of this approach compared to DIY / cloth face coverings would be protection for BOTH the wearer in addition to the public.  It is my understanding that the cloth / DIY options are mostly meant to protect others.  It also is a less wasteful approach as the only waste would be the filter insert.

I would like to thank The Billings Clinic, my employer 3D Printing Colorado, Associated Thermoforming Inc, as well as the various physicians, of particular note - Dr. Centeno of Regenexx that provided the critical feedback needed to make the product better for the end user.

Sources

https://www.billingsclinic.com/foundation/3d-printed-surgical-mask/

https://regenexx.com/blog/3d-printed-n95-mask-for-clinics/

https://3dprintingcolorado.com/

https://ati-forms.com/