PURPOSE: To offer a cylindrical filter which does not need reinforcing material for maintaining shape and has an substantial large filter area and stable filter performance.
CONSTITUTION: This cylindrical filter consists of a cylindrically formed three dimensional fabric structural body F with one end closed by a closing member 4. The three dimensional fabric structural body F is composed of circumferential yarn 2 comprising a large number of fibers circumferentially wound and of a large number of radial threads 3 continuously inserted into the bed of the circumferential yarn 2 in the axial and radial directions in the meandered state so that they may turn back in the middle of the bed of the circumferential yarn 2. The radial threads 3 different in the turn position are circumferentially arranged with the prescribed separation distance and the turn positions of the adjacent radial threads are arranged in the state that they have axially delayed phases from each other. And yarn 27 is wound on the outer circumferential surface of the three dimensional fiber structural body F.
YASUI YOSHIHARU
TSUZUKI MAKOTO
KAMIYA RYUTA
