Donna ChenMay 3, 20201 min readKN95 FFP2 Mask Layer StructureSchematic presentation of the layer structure of an KN95 FFP2 maskSchematische Darstellung der Schichtstruktur einer KN95 FFP2-Maske
Schematic presentation of the layer structure of an KN95 FFP2 maskSchematische Darstellung der Schichtstruktur einer KN95 FFP2-Maske
Irreversible Photochromic PigmentColour appears irreversibly when exposed to UV but not the visible light The irreversible photochromic products show their colours when exposed to UV but not visible light. Unlike the reversible photo