Monday, March 23, 2020

DIY Protective face mask

Given the current shortage of self protective gear, due to Coronavirus spread, here is a how we decided to face the emergency building face masks, for our colleagues and workers.
I took the basic design from this facebook post, then adjusted the design, added details and completed the description.
Production of this kind of facemask can be pipelined, and several people can collaborate. Some preexisting experience with sewing machine usage is useful.

This face mask is not medical grade, is not certified. However, given the shortage, it is probably better than nothing.

The mask is made with two fabric layers, and there is a pocket where you can put some filtering material inside, to be changed every day.
After removing the filter, the mask can be hand washed or machine washed in high temperature, together with underwear.
Many different filtering materials can be used. Paper napkins, paper handkerchiefs, kitchen papers, hygienic lady pads, microfiber, non-woven material, toilet paper...

To build the face mask, you will need an ironing board, and a sewing machine. I use strong polyester thread.
Required Materials:
3 pieces of fabric (i use non-stretching cotton fabric):
    1x 40x20 cm, that will become the main part.
    2x 11x4 cm, that will become the two "ears" to hold the elastic bands.
2x 30 cm pieces of elastic band.
1x 10 cm metal wire, to make the nose pinch

Construction procedure

1. Cut fabric parts, and make a 1cm hem on both the 20 cm sides of the large fabric piece, and on both the 4 cm sides of the two smaller pieces. Preiron the hems before sewing.

2. On the large piece, create a 2 cm fold on one of the 20 cm sides, and iron it. Now fold in half and iron the central fold. Folded sizes should now be around 18x20cm. (40-(1+1+2))/2.

3. Fold in half the small parts, along the long side and iron. They should be identical, with a 9cm length.

4.Open the large piece, with hems facing down, and create 3 creases on each side of the center fold, so that the final height of each half is 9cm. Keep on the bottom the part with the 2 cm fold downside. Use iron after creating each crease. It can help to first try to do it on a paper model, having traced some lines parallel to the center fold, starting from the center fold, with the following interspaces: 4,1,2,1,2,1cm.
The following illustration depicts the folds you have to create.  The dashed line is the center fold. The outside of the mask is on top. Work each half then iron to keep the folds in place.

5. After ironing the folds, sew the sides to lock the folds in place.

6. Fold the front along the center dashed line, keeping facing the two "outside parts" and sandwiching in the two "ears", with their vertical folds towards the inside.

7. Stitch along the two sides, sewing in the ears inside out.

8. Turn the whole inside-out, and sew additional 5 cm from each side on the part still open, leaving a central hole to allow filter placement.

9. Insert on each side a piece of 30cm of elastic band. Use a safety pin or a hook to pass it through the hole. Tie a knot and then push the knot inside the fabric, so to make it not visible.

10. A 10cm metal wire can be inserted and fixed in the top central part, with some top stitch from the outside, to be pinched around the nose, and have a tighter fit.