| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a water cut-off ring which can obtain the endless annular water cut-off ring having sufficient water stop performance and enabling fitting to a pipe body such as a sleeve pipe with a small diameter. <P>SOLUTION: In the method of manufacturing the endless annular water cut-off ring 1 which includes a foam portion 3 in a foamed state comprising non-aqueous expansive rubber and an aqueous expansion portion 5 integrally formed to cover the outer periphery of the foam portion 3 with aqueous expansive rubber and has a predetermined cross sectional shape, a non-aqueous expansive rubber material serving as the foam portion 3 and including a foaming agent and an aqueous expansive rubber material serving as the aqueous expansion part 5 are integrated by a mold, so that the non-aqueous expansive rubber material becomes a core and the aqueous expansive rubber material surrounds the periphery of the core. Extrusion molding is performed to obtain a string-shaped body having a predetermined cross sectional shape in an unvulcanized and unfoamed state, and the string-shaped body is cut to have a predetermined length. End faces 7, 7 comprising cut faces are bonded to each other by an adhesive to form an annular body 13. The annular body 13 is fitted to a ring-shaped mold 15. The annular body 13 is heated within the ring-shaped mold 15, vulcanized and foamed, so as to obtain the endless annular water cut-off ring 1. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
