| 摘要 |
PURPOSE:To form a filter plate with almost no warp by finishing an unfinished plate which closely resembles a filter plate having near-symmetrical convex strips in the thicker direction of a circumferential brim through the cutting of one of the convex strips. CONSTITUTION:A material synthetic resin is formed by a molding press into an unfinished plate 5 having an upper convex strip 5a and a lower convex strip 5b almost symmetrically provided in the thicker direction of a circumferential brim. Later, the upper convex strip 5a is cut off and machined into a final filter plate form. Polyolefin, PVC resin, polystyrene, polycarbonate, ABS resin, polyacetyl resin, etc. are used as synthetic resins. A warp in the planar direction of a filter plate of this invention is 0.2mm or less. |
