| 摘要 |
Workpieces of a non-metallic kind, such as particle boards, fibre boards and masonite boards, are surface- treated using discs, sheets and leaves in which abrasive grain is immovably applied and in which the discs are rotated about an axis perpendicular to the surface which is to be treated. In order to increase the degree of fineness of the treatment, the abrasive grains are arranged resiliently on the said sheet, leaf or disc. <IMAGE> |
