PURPOSE: To improve filtration durability by changing the insertion density of wefts in the thickness direction of a three dimensional fabric structure in the title filter comprising warps, wefts, and vertical threads so that the size of openings produced at the intersections of fiber bundles in the fabric structure is different between one side and the other side in the thickness direction.
CONSTITUTION: The title filter 1 is composed of warp layers comprising warps Z arranged in parallel to the longitudinal direction of a fabric, wefts arranged in the lateral direction of a fabric rectangularly crossing with the warps, and vertical threads being continuous on each line arranged along the thickness direction of the fabric rectangularly crossing with the warps Z between the respective lines of the warp layers. The insertion density of wafts changes in the thickness direction of the three dimensional fabric structure so that the size of voids produced at the intersections of fiber bundles in the fabric structure F is different between one side and the other side in the thickness direction. As the result of this structure, a reinforcing material for the maintenance of the form becomes unnecessary, and the filtration area is substantially increased to improve the durability of filtration effects.
YASUI YOSHIHARU
TAKIMOTO KAZUHISA
SASAKI KAZUE
