| 摘要 |
PURPOSE:To manufacture the abrasive material of synthetic resin having a sharp grinding edge efficiently by crushing the synthetic resin under cooled and hardened condition. CONSTITUTION:Rough grains 8, made by crushing the blocks of the thermocuring resin and having an average grain diameter of the degree of 5mm., are stored into a rotary drum 1 together with hard balls 9 of steel and the drum is rotated at the peripheral speed of 5-20m/min. On the other hand, cooled gas of -100- 0 deg.C is introduced into the rotary drum 1 through a conduit 3 and a rotary valve 2 from a cooled gas source 4. Then, the rough grains 8 are cooled to a low temperature and become brittle, therefore, the crushability thereof is improved and are pulverized highly efficiently by the compression force and impact force of the hard balls 9, accompanied by the rotation of the rotary drum 1, whereby the polygonal abrasive material 11, having the sharp cutting edges 10, may be obtained. |
