| 摘要 |
PURPOSE:To maintain the ready use state for a long period by covering the effective polishing surface with the polyvinyl acetal group porous material impregnated with the water group liquid in 500wt% for the dried weight, thus effectively preserving humidity. CONSTITUTION:A plurality of segment-shaped fixed grindstones 1 are installed onto the polishing surface of the metal surface plate 2 of a both-surface lapping polisher, and the fine polishing for an aluminum plate is carried out for 6 days. When introduced onto a stop base, the polishing working surface of the undersurface of the surface plate is covered by the sheet having a thickness of 10mm which is made of polyvinyl acetal PVAt series porous elastic body having an average hole diameter of 60 without cleaning the polishing acting surface, and the upper surface of the surface plate is slightly attached onto the sheet, impregnated with the max, saturation quantity of water, and the state of the acting surface is observed at each 12hr. Thus, the acting surface can be kept for 240hr or more free from the hardening deterioration. Therefore, the surface plate can maintain the using state for a long period for ready use by covering the surface plate with the PVAt porous sheet impregnated with the water group liquid in 500wt%. |
