| 摘要 |
PURPOSE:To contrive to stabilize the quality and to improve the productivity by a method wherein a water retentive layer is provided on to the inner wall of a cylindrical case, in which liquid rubber composition and a mandrel are inserted in order to remove them from the case after the curing of the composition. CONSTITUTION:Highly water-absorbable polymer is sprayed onto the inner wall of a case 1, the inner surface of which is cylindrical and both ends of which are open, in order to provide a water retentive layer 2, which fully absorbs moisture by being placed in highly humid atmosphere or water. Next, a lower cap 3 for centering is mounted to the bottom of the case so as to make the coating thickness of rubber to a mandrel uniform. A blind hole 4 into which one end of the mandrel is to be fitted is provided on the cap 3. The pouring of liquid cold-setting silicone rubber 5 and the setting of the mandrel 6 are performed. In addition, an upper cap 7 for centering is mounted to the upper part of the case. A mixture of 100 parts by weight of addition reactive dimethyl borosiloxane, 20 parts by weight of silica, 5 parts by weight of silicone oil, platinum catalyst and crosslinking agent is employed as the cold-setting silicone rubber. The product is removed after from the case being left for about 8-15hr after the pouring. |
