| 摘要 |
<p>PURPOSE: To make after treatments such as moving to sealing locations and getting treated be easily conducted by obtaining a magnetic fluid by dispersing powder magnetite in a solvent, the melting point of which has been adjusted to a temperature higher than the sealing temperature, and granulating and solidifying the fluid. CONSTITUTION: Magnetite of ferromagnetic metal powder or oxide powder coated with a dispersing agent is dispersed in solid paraffin, the melting point of which has been adjusted to 60 deg.C, and granulated to granulars having diameters of about 3-5 mm. A suitable number of granulars are inserted into a tube 1 having an internal diameter of about 10 mm, moved to the desired position and heated to about 65 deg.C by a drier outside the tube while secured by a permanent magnet 3. The plug material 2 thus obtained is in a liquid state and forms a plug 4 in the tube 1. Then it is cooled to chamber temperature while secured by the permanent magnet 3. The solidified plug 4 has the same sealing function even after the magnetic field is removed.</p> |
