Status of information: 31 March 2020
Important note: The Do-It-Yourself (DiY) face mask is not a medical product that provides medically standardized mouth and nose protection. It is not a medical respirator, there is no FFP standard and no certification.
Either a two-layer tea towel or a single-layer cotton T-shirt (made of 100% cotton) can be used as an insert in the filter attachment while maintaining good breathability when wearing the mask (see Reference 1 to Reference 3).
Components of the do-it-yourself face mask:
What is needed for assembly:
The plastic of the mask consists of polyethylene terephthalate (PETG) modified with glycol, acrylonitrile butadiene styrene (ABS) or acrylonitrile styrene acrylate (ASA). As a rule, these types of plastics should not lead to skin intolerances. Polylactide (PLA) is not suitable for printing the face mask as PLA warps during disinfection in the oven.
1. Wash the fabric for the filter (two-ply tea towel or single-ply cotton T-shirt) in the washing machine at a minimum of 90°C before first use Disinfect the face mask, filter attachment and hose at 65 °C for 45 minutes in the oven. For further information see "Disinfecting the mask".
2. Cut the cotton T-shirt according to the measurements for the filter attachment of the face mask. To do this, place the T-shirt in the filter attachment and move it along the edge of the filter attachment with a felt pen. Then cut out the fabric filter from the T-shirt along the markings with scissors. When using a dishtowel as a fabric filter, first lay the dishtowel twice and then cut it out along the filter attachment.
3. Carefully cut the hose lengthwise with scissors or a carpet knife. Cut a 4 cm long piece of the hose for the lower edge of the face mask. The rest of the hose (approx. 9 cm) is for the nose piece of the face mask. Place the tubing along the edge of the face mask and press down firmly so that the tubing acts as an edge protector. The tube should be secured with adhesive tape to prevent the tube from coming off.
4. Pass an elastic band through the two fixing loops on the left side of the mask at the top and bottom. The rubber band should overlap about 2 cm to staple the two layers of rubber band together at both ends in step 2 using a stapler. Place the mask against the face so that the mask is flush with the face and guide the elastic behind the left ear. The elastic band should overlap 2 cm at each of the two fixing loops. The elastic band fits well if it is slightly under tension without cutting into the ear, if the mask is pressed too tightly against the face or if the ear is turned down. The elastic band must not be too loose, otherwise the mask will not fit the face. The mask also sits uncomfortably on the face.
5. Fix both ends of the elastic band with a staple. If necessary, the elastic can be shortened with scissors to the appropriate length.
6. Repeat steps 4 and 5 for the second elastic and the right fixation loops (from the view when the mask is on).
7. Place the fabric filter in the square filter attachment and then press the filter attachment onto the face mask so that the filter attachment is firmly seated on the face mask The filter attachment must not have any open areas, but must be flush with the face mask.
For more information on wearing a face mask, see Reference 4 to Reference 6.
Note: The mask should not be worn for more than six hours per day. Afterwards the mask and the fabric insert should be disinfected.
1. Paddy Robertson. Smart Air. What Are The Best Materials For Making DIY Masks? https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/
2. Marianne van der Sande, Peter Teunis, Rob Sabel. Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population. PLoS One. 2008; 3 (7): e2618. DOI: 10.1371/journal.pone.0002618
3. Anna Davies, KatyAnne Thompson, Karthika Giri, George Kafatos, Jimmy Walker and Allan Bennett. Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic? Disaster Medicine and Public Health Preparedness 7 (4): 413-418 August 2013. DOI: 10.1017/dmp.2013.43
4. NDR podcast Prof. Drosten (Charité Berlin) on wearing masks: https://www.ndr.de/nachrichten/info/podcast4684.html (in German)
5. Do-It-Yourself Masks - Instructions and information: https://maskeauf.de (in German)
6. Andreas Dorow. When to wear a face mask: https://youtu.be/dvlh7F9-nsI (in German)
This project is carried out in the Innovation Laboratory Digitization, funded by the Carl-Zeiss-Stiftung