... FINE POWDER DF-201 Excellent Grade A Qualified Smoothness & Cleaness White sheet surface,fiber is average,no gravel and metalic powder ... ≤1 for mechanical impurity(≥0.5mm)or organic impurity(≥2mm) White sheet surface,fiber is average,no gravel and metalic powder ... ,on which there are brand,trademark,executive criterion.type,grade,lot NO.and net content,pack date, checker,,packager. 2.PTFE ...