We use a process called silver impregnation in our Cambridge Masks.
Silver impregnation begins with the raw material for our carbon cloth which is viscose rayon. Viscose rayon offers improved filter metrics over granular or coconut-based carbon. We impregnate this with silver prior to running it through a double furnace system. During the heating process, the particulates from the silver coat soak into the pores of the carbon cloth.
The carbon cloth is then sealed with a protective layer of polypropylene (not the same material as melt-blown polypropylene found in our middle-layer filter), which is laminated onto the fabric.
This part of the process contains silver and prevents any loose silver particles from escaping the fabric. You can see this laminated, shiny cloth on the inside of your mask.
If you have further questions, please contact us by email at firstname.lastname@example.org or Chat button on our sites to connect with our Customer Service Team