The Covid-19 pandemic has put a lot of stress on medical supply chains. Daily we hear about personal protective equipment shortages. All types of face masks are in short supply and in very high demand. Unfortunately, as caseloads increase, this problem will only get worse.
While researching new plastics for 3d printing, I found a company called Copper 3D. This company manufactures Antimicrobial PLA plastic for 3D printing, but that is not what really grabbed my attention. They have released an open-source 3D model file for a reusable face mask called the Nanohack. This face mask is still being developed, but shows promise. I decided to download the files and print them out with no changes to see how good the design works.
The face mask is printed flat and in three separate pieces. The first part printed out was the face mask itself. All models were printed with 20% infill and no support.
The filter cover and inner honeycomb disc were printed next. There was enough room to print these with the main part in the machine, but I wanted to see how it turned out before wasting plastic. A high thread count cotton cloth will be placed over the inner honeycomb disc and placed in the filter chamber. Since this is just a test unit, I have not made any filters for this mask yet.
Before the mask is formed, the filter cover has to be installed. The mask is formed by heating the printed plastic and bending it to shape. Installing the filter cover keeps the filter chamber from deforming while heated.
To heat the plastic, I used the heat gun on my soldering rework station. It has temperature controls and it was easier to set the temperature low enough to soften the plastic but not melt it.
Forming the plastic was not the easiest. First, the plastic was heated and the rough shape of the mask was formed. Once I had the rough shape, the plastic was heated again, taking care to not overheat and formed to my face. This worked, but was somewhat difficult. Once formed to my face, the nose bridge and the chin section were glued in place using cyanoacrylate. After gluing, the mask was heated again to seal the mask to my face.
After some trial and error, I was able the get the mask to make a good seal. The forming process would have been much easier if a form like a mannequin head was used. This would also have been much safer. The downfall to this is a perfect seal would almost be impossible to achieve. A gasket may be able to make up any gaps left from not custom fitting and will be investigated.