... the defense industry, electronic instrument, medical, food industry and textile industries, etc.3. Characterized by stable property, ... dust holding capacity, high efficiency, low air resistance and high strength, etc.4. It is an ideal ... products are divided into three types (ASHRAE, HEPA and ULPA).ClassificationGradeThicknessMDCDStiffnessFilter EfficiencyFilter ResistanceASHRAEF60.35-0.381.20.51. ...