... easy to be obsructed 3. oil and water speration PE Dust Collector Bag 1. The Polyester needle felt is made of ... surface more smooth, not easy to be obstructed by the dust voidage.3. The polyester needle felt applied widely and has ... water seperation and filtration.5. Applicable to mine, limestone, cement, iron, and steel industries, alumina delivery, electrolytic aluminium, non-ferrous metal ...