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 plasem,coal and sludge sewatering chemical engineering, the wine bran dehydrate, the vineger bian dehydrate ect. It is s est to used on the dryness part of paper machine low air permeability.