I'm wondering if there's not a typo in a recent paper that says that
to control the COVID-19 outbreak, the Chinese government imported more than 2.0 billion facemasks between 24 Jan 2020 and 29 Feb 2020
(FWIW, the claim has been reproduced in the Daily Mail now.)
Are there any other sources corroborating this (gigantic) number? (Did the world even produce 2.0 billion masks in a month? If not, where did they find such stockpiles?)
Actually, regarding production, I did find some more recent figures
the New York Times has reported [on March 23] that China is now producing 116 million masks a day, 12 times its supply prior to the outbreak.
So if China produced about 10 million masks/day earlier, that puts their production (back then) at around 300 million/month. Did the world produce 6-7 times that (back then)? It's not totally implausible, but given that China is usually the major manufacturer for such items, it's not entirely obvious that the claim is true either.