To provide a manufacturing method of an annular hollow body capable of sufficiently preventing unexpected adhesion or the like even if the overlap joining region of a cylindrical member itself is positioned in opposed relation to the inside and outside in the radial direction of the cylindrical member by the folding-back of the end part of the cylindrical member to an outer peripheral side and capable of effectively preventing the non-intentional adhesion or the like of the inner surface of the molded annular hollow body even if the mold release sheet bonded to the outer peripheral surface of the cylindrical member is peeled from its surface in molding the annular hollow body is peeled or allowed to fall off.
After the respective end parts of a one unvulcanized rubber sheet 2 are mutually joined in an everlapped state to form the cylindrical member 3, both end parts in the axial direction of the cylindrical member 3 are folded back to the outer peripheral side along with the release sheet 4 on the outer surface of the cylindrical member and both end parts of the cylindrical member 3 are joined in an overlapped state in this folded-back posture to obtain the annular hollow body. After the cylindrical member 3 is formed, both end parts in the circumferential direction of the release sheet 4 on the outer surface of the cylindrical member 3 are joined in a cylindrically overlapped state.
Hiroshi Tokunaga
Yoshiyuki Iwasa
Shiro Fujitani
Kiyoshi Kuruma
Kazuyuki Tomita