| 摘要 |
A grinding or abrasive agent on an underlay comprises spherical grinding granules bonded to the underlay and each comprising a large number of abrasive grains. The spherical granules contain the abrasive grains embedded in an organic binding agent matrix, the hardness of which is not harder than the normal binding agent which is used for bonding the spherical granules to the underlay. Pref. the spherical granules contain 80-97% of abrasive grains and 3-20% of organic binding agent matrix. Up to 60% of the organic binding agent matrix may be replaced by fillers. The organic binding agent matrix pref. comprises a phenol formaldehyde resin, urea formaldehyde resin or malemin resin. The mean dia. of the spherical granules is pref. 300-2000 mu and is 3-500 times the mean dia. of the abrasive grains. A high, uniform grinding performance accompanied by a long-lasting roughness depth is obtd. without a tendency to become prematurely clogged. Due to the relative softness of the binding agent between the abrasive grains in the spherical granules, the abrasive grains are continuously and uniformly exposed to provide the grinding action, without a risk of the surface of the workpiece becoming scratched, since the granules themselves do not act as a large abrasive grain. |
