... tube,elastic belt and unsintered ta PTFE FINE POWDER DF-201 Excellent Grade A Qualified Smoothness & ... surface,fiber is average,no gravel and metalic powder,even sheet texture ≤1 for mechanical impurity ... surface,fiber is average,no gravel and metalic powder,allow 0.5mm organic Impurity. 2 Tensile Strength ... packager. 2.PTFE should be stored in clean dry warhouse to prevent from dust,moisture,etc,foreign ...