Introduction: Face Shield for Corona Virus/Covid19 Without a 3D Printer
As reports around the world continue to grow of personal protective equipment (PPE) shortages in hospitals due to the outbreak of the Covid19 corona virus, many people have begun 3D printing face shields, face masks and other medical equipment to meet the demand. While it is great to see so many making use of 3D printing in this innovative way to help their communities, we shouldn't overlook other methods of producing these same simple items which may be more efficient, more economical or simply more accessible to a wider range of people looking to help.
A great example of this approach to not over thinking the problem is this design from Carl Bass which attaches a clear shield to a baseball cap:
Been working on some cheap homemade ways to get disposable face shields into the hands of medical practitioners who desperately need them. Cost about $1 each pic.twitter.com/LfShYfrrDQ
— Carl Bass (@carlbass) March 25, 2020
Note: Since initially posting this Instructable at the start of the pandemic, several companies like Apple have started producing similarly simple shield designs (https://www.theverge.com/2020/4/5/21209270/apple-face-shields-masks-covid-19-coronavirus) and others have begun injection molding parts at scale which is good to see.
Supplies
This Instructable looks at several simple ways in which protective face shields can be made with a projector transparency sheet or other piece of clear plastic and generally available materials/tools. The methods listed below require the following materials:
Method 1: Sheet of plastic, rivets and rivet gun, washers, rubber band, transparency sheet.
Method 2: Sheet of plastic, zip-ties, rubber band, transparency sheet.
Method 3: Foam insulation strip, rubber band, transparency sheet.
Method 4: Rubber band, stapler, transparency sheet.
Method 5: Rubber band, stapler, transparency sheet.
Method 6: Rubber band, transparency sheet.
Method 7: Rubber band, zip-ties, transparency sheet.
Method 8: Large zip-tie, transparency sheet.
Method 9: Transparency sheet.
Method 10: Silicone mold material and casting urethane
Step 1: First, Some Questions...
- Are the face shields described below as robust as commercial grade units?
No, of course not. They are quick and easy alternatives when commercial grade units simply are not available, that in some cases can be assembled on the spot within a hospital as needed.
- Why is this better than 3D printing face shields?
It's not necessarily better or worse. 3D printing is great for producing complex geometries and prototyping new designs but is generally a slow process. For example, the Prusa face shield that has been widely shared as an example of 3D printed PPE, takes about 2-3 hours to print. A typical user printing face shields at home 24 hours a day will only produce between 8-12 units per day.
Prusa states: “Thanks to our 3D printing farm, the largest in the world with over 500 3D printers, we are able to produce 800 pieces a day.”
This is great and very helpful for local hospitals but pales in comparison to the expected demand some estimate to be in the millions of units over the coming months.
- Is there a better way to make these face shields?
Yes! Frankly speaking, we think the best way to manufacture PPE like face masks is using traditional manufacturing methods such as injection molding. If manufacturers of existing products can't scale up their own production, consider reaching out to a local injection molding business who may have available capacity due to the economic downturn and be willing to donate some of their design services or offset the tooling costs for this good cause. After the relatively high initial tooling costs, injection molded shields can be produced by the thousands per day at a minimal part cost.
We have even seen several people buying thousands of dollars of 3D printers and filament for the sole purpose of producing face shields. Again, we applaud their willingness to help, but those thousands of dollars could pay for the mold tooling that would far exceed the output they will be able to achieve printing parts at home. Check out the conclusion section below for more.
Step 2: Method 1: Rivets and Plastic Sheet
This method attempts to re-create the general shape of a typical 3D printed shield design with an inner and outer arc by utilizing two strips of plastic held together with rivets.
Step 1: Cut a strip of thin plastic to ~20" long by ~1" wide.
Step 2: Cut the strip of plastic into two pieces, ~11" and ~9" long.
Step 3: Drill a hole (corresponding to the size of rivet you have) at each end of both strips of plastic. Optionally, cut a third hole in the center of the longer strip for added support for the visor.
Step 4: Cut open the rubber band and pierce each end.
Step 5: Use a single or three hole punch to cut holes in the outside edges of the transparency sheet.
Step 6: Insert a rivet through the pierced hole in the rubber band, the short plastic strip, the long plastic strip, the transparency sheet and the washer. Rivet the stack of materials together.
Step 7: Using a second rivet, align and stack together the materials on the other side and rivet together.
Note, the washer is used to distribute some of the force of the rivet to prevent it from pulling out of the plastic. It may not be needed depending on the type of plastic and rivets you are using.
Step 3: Method 2: Zip-Ties and Plastic Sheet
This method is the same as Method 1, but replaces the rivets with Zip-Ties. The zip ties are not as robust as rivets, but are more readily available.
Step 1: Cut a strip of thin plastic to ~20" long by ~1" wide.
Step 2: Cut the strip of plastic into two pieces, ~11" and ~9" long.
Step 3: Drill a hole at each end of both strips of plastic. Optionally, cut a third hole in the center of the longer strip for added support for the visor.
Step 4: Cut open the rubber band and pierce each end.
Step 5: Use a single or three hole punch to cut holes in the outside edges of the transparency sheet.
Step 6: Insert a zip tie through the pierced hole in the rubber band, the short plastic strip, the long plastic strip, and the transparency sheet. Zip tie the stack of materials together.
Step 7: Using a second zip tie, align and stack together the materials on the other side and zip tie together.
Step 4: Method 3: Foam Strip
This method attempts to recreate the commercial face shield design shown which does not utilize a rigid frame but simply has a foam forehead pad attached to the clear visor.
Step 1: Use a single or three hole punch to holes in the side of the transparency sheet.
Step 2: Cut open a rubber band.
Step 3: Tie each end of the rubber band into the holes in the transparency sheet.
Step 4: Cut a length of adhesive backed foam to ~10" and apply to the transparency sheet.
Alternative: Instead of punching the transparency sheet and tying off a rubber band, simply apply the foam strip and use an intact rubber band around the head as shown in Method 6.
Step 5: Method 4: Rubber Band and Stapler
This method is similar to methods 1 and 2 but utilizes the transparency sheet itself to create the inner forehead arc instead of a separate piece of stiffer plastic. This results in a less robust structure but is extremely easy to make.
Step 1: Cut a transparency sheet into ~1" strips in the short direction (11 eight inch strips).
Step 2: Use one of the strips and align it with the edge of a new sheet staple the two together.
Step 4: Curve the 1" strip to align with the other end of the full sheet and staple together.
Step 5: Insert a large rubber band behind the 1" strip against the staples.
Step 6: Add an additional staple through both sheets on each side to secure the rubber band in place.
Note: If a large rubber band is not available, multiple smaller ones can be cut open and tied together or another type of elastic or string can be used.
Step 6: Method 5: Rubber Band and Stapler
This method is similar to Method 4 but eliminates the inner forehead rest all together for simplicity. This will bring the visor closer to the users face and may cause it rest on their nose but is faster to produce.
Step 1: Cut open a rubber band.
Step 2: Use a stapler to secure the rubber band to one side of the transparency sheet.
Step 3: Fold the rubber band around to the opposite side of the sheet and staple it through the sheet.
(An alternative to stapling the rubber band through the transparency sheet is to use a hole punch to create holes in the sheet and simply tie the rubber band off through each hole as shown in the attached photos.)
Step 7: Method 6: Rubber Band
This is as simple as it gets. While it might look a little silly and not be the most comfortable solution, at the end of the day if there is no alternative, a large rubber band and a single transparency sheet could be all you need to provide protection. Total cost: ~15 cents.
- Step 1: Place a large rubber band around your head.
(If you do not have large rubber bands, cut open and tie several together.)
- Step 2. Slide the transparency sheet under the rubber band. That's it!
(This method can be used with the foam strip from method 3 for added comfort.)
Step 8: Method 7: Zip Ties and Rubber Band
Step 1: Use a single or three hole punch to put two holes in the transparency sheet.
Step 2: Zip tie a large rubber band to one of the outside holes.
Step 3: Zip tie the rubber band to the opposite side hole.
Step 9: Method 8: Large Zip Ties
Step 1: Use a single or three hole punch to put three (or more) holes in the transparency sheet.
Step 2: String a large (~30") zip tie in and out through the three holes in the sheet
Step 3: Zip the loose ends together lightly, leaving room to cinch tighter when in use.
Note, use multiple medium sized zip ties zipped together if a single large one is not available. Example shows three 12" zip ties.
Step 10: Method 9: Origami
This method uses a single transparency sheet and nothing else!
Step 1: Cut a ~0.75" strip on one side of the transparency sheet, stopping ~0.75" before cutting all the way through.
Step 2: Cut several slits perpendicular to the strip at the loose end.
Step 3: Cut a ~0.5" strip on the opposite end of the transparency sheet, stopping ~0.5" before the end.
Step 4: Cut the end of the ~0.5" strip into an arrow shape as shown.
Step 5: Bend both of the strips at a 45° angle so that they stick out in either direction.
Step 6: Slide the "arrow" through one of the slits to secure.
Optional: After bending at 45°, crease and flip the strips up one more time and secure with a staple.
(This can be cut by hand or using a vinyl cutter or laser cutter with the attached DXF or PDF files.)
Attachments
Step 11: Method 10: Casting
Instead of using a 3d printer to produce the final product, you can also either directly print a mold (inverse of your part) or cast the printed shield part in silicone to create a mold. These molds can then be used to produce multiple copies at a faster rate (some cast urethanes are available with a cure time of just a few minutes) or from materials better suited for a medical setting (autoclave compatible).
The attached STL file is of a simple shield design for casting which includes a draft angle to make removing parts from the mold easier. The tabs on the shield are spaced to work with a standard three-hole punch spacing for the face shield.
Step 12: Conclusion
As mentioned at the start, the methods described above are simply alternatives to when commercial units are not available and mostly meant to encourage you to consider alternatives to spending 2-3 hours to 3D print a single face shield when simpler methods may suffice.
We are seeing 3D printing services selling these shields for about the same price as a custom injection molded part can be made with the tooling cost actually being cheaper than the cost of 3D printers required to meet the same volume. If you already have a 3D printing farm to dedicate to this cause that is great. If not, please consider raising money and working with local injection molding companies who may be able to produce more parts faster and cheaper. This will also help to simplify the logistics for shipping and receiving by having a single local source of parts.
