Press and filtrate fabrics by filling wad into the spiral fabrics to reduce the air permeability,so orifice change to compact,reduce matter running out from fabrics、transverse erect,it is major used to making paper wash plasm、coal and sludeg sewatering chemical engineering,the wine bran dehydrate,the vineger bran dehydrate etc.It is suggest to used on the dryness part of paper machinein low air perneability.