DIYing PPE: How to Protect Against COVID-19

For the past few weeks, SMMA has mobilized its 3D printing equipment to create Personal Protective Equipment (PPE) in the form of face shields, helping to combat challenges faced by healthcare professionals in the wake of the recent COVID-19 crisis. Currently, the finished products are being donated to local healthcare professionals. Here’s what we learned from the process, and how we are leveraging our design technology resources to keep frontline workers safe:

Organizing a Team

Our PPE team consists of a small and focused group with direct experience in fabrication. This helps maintain safe social distancing and sanitization protocols. Currently, this team is comprised of four members: Jason Pieper, an Architect with prior experience in casting, alongside David Darling, Matthew Paquin, and Raabe Rocha, all Design Technologists who manage the physical fabrication process.

The Process

Our team established an efficient 10-step process, from creation to shipment. Once the molds are cured, it's possible to make upwards of 20-30 shields in a two-hour period:

  1. All team members put on protective masks and gloves.
  2. Starting with a headband model that was downloaded from the National Institutes of Health’s (NIH) website, the team creates their own Rhino/Grasshopper model for efficient molds.
  3. The 3D-printed headbands are then glued down to a sheet of acrylic, where the molds are filled with a tin-set silicone rubber product.
  4. A urethane plastic is cast into the silicone, curing in about 30 minutes.
  5. The headbands are then taken out of the mold and allowed to strengthen overnight.
  6. Any sharp edges or imperfections are taken off with a belt sander, and a skin-safe silicone epoxy is applied to the headbands.
  7. Standard binder covers are three-hole punched and fastened to the headbands.
  8. The headbands are then rinsed in a bath of water/isopropyl alcohol mix and dried with a clean paper towel.
  9. The clear shield material is wiped with a Clorox wipe and also dried with a clean paper towel.
  10. Finally, all components are sealed in a one-gallon Ziploc bagged and shipped out via FedEx.

Tools and Products Used

All the equipment used is easily accessible and affordable, providing opportunities for other design firms and technology-oriented individuals to partake:

  • The Machine: We have been using an Ultimaker S5 to do all the printing, which has successfully been working around the clock for the better part of five weeks.
  • The Models: Though we initially used the PRUSA RC3, we have since switched to the Toledo for both casting and printing purposes.

Challenges

We came across several obstacles that could impact any team attempting to DIY their own PPE:

  • With so many different examples within the fabrication community, we had to make sure that we researched the concept. At first, we had discovered discussions around a PRUSA-generated design, where the model files were already prepared and the process had been documented. With a priority around speed-to-product, we decided to use the design as our guide while knowing that output would be limited, since it depended on a large portion of the design being 3D-printed. This prompted a member of our team to explore ways to batch create products using a different prototype called the Toledo, which could be cast. We ended up splitting the effort into two paths, both of which relied on PLA filament, clear plastic sheets, and elastic bands.
     
  • A few weeks prior to our government’s shutdown, we anticipated delays in material supply chains and had ordered extra stock of materials. Fortunately, PLA filament made the list, but it left us to track down the plastic sheets and elastic bands from local sources. These proved much more difficult to obtain.
     
  • Finally, there was the scheduling. Nearly the entire effort was organized virtually, in-between our newly remote jobs and personal responsibilities. Coupled with finding safe and appropriate times to re-group in-person, it became mandatory to maintain active communication to determine the best times we could work without negatively impacting our production.

The Output

Our process has been able to produce 30-50 pieces of PPE a week, which we project to remain at a steady pace for the foreseeable future. So far, we’ve successfully delivered over 200 face shields and plan to continue producing PPE until the need starts to taper off.

Our Advice

As soon as you have a prototype, start looking into material availability. Your selections will likely dictate the rest of the fabrication process and through-put. If you’re seeking additional support, check your local resources. Several groups in the fabrication community have been organized for this purpose and some of the larger hospitals have created avenues for small shops to participate in coordinated efforts.