PURPOSE: To make it possible to form, as designed, unevenness on the upper and lower both sides of a resinoid cutting grindstone by subjecting a grindstone raw material to press molding with a top and bottom metal mold obtained by forming desired unevenness over the whole pressing surface.
CONSTITUTION: An adhesive 9 is applied over the whole upper surface of a metal mold 3 after cleaning said surface, and in the same way as in said metal mold 3, said adhesive is applied over the back of a sheet 6 which has been cut into a record plate shape. By stretching the sheet 6 on the upper surface of the bottom metal mold 3 and pressing them via a cushion material 10 such as currugated fiberboard paper under the pressure of 50W70kg/cm2 for 5W10min, a metal mold provided with desired unevenness 12 formed over the whole upper surface of the metal mold 3 is obtained. Then, by pressing said bottom mold under a proper condition with a top mold comprising a metal mold 1 after putting the raw material of a grindstone 2 into said bottom mold, unevenness being reversely symmetrical to and having the same depth as that on the metal mold surface is formed on the both sides of the grindstone.
JPS5524836A | 1980-02-22 |