| 摘要 |
1290413 Modifying engraved surfaces STAUFFER CHEMICAL CORP 11 Sept 1970 [15 Sept.1969) 43565/70 Heading C7B [Also in Division B6] An engraved surface suitable for use in embossing, such as a roller, plate or die is improved by electro-polishing, electro-plating with a metal having a high to medium levelling effect, and electro-plating with another metal having a relatively lower levelling effect. The three steps may be performed in any order. The high-medium levelling effect metal may be copper, iron or nickel, and the lower may be chromium or nickel. Where a roller is used it may be constructed of ferrous alloys, aluminium or its alloys or metal coated plastics material. The substrate for engraving may be drapery material, upholstery, table cloth fabric, leather, reptile or animal skin, wood, tapestry, carpeting, aluminium foil, linoleum, vinyl materials or paper. The engraving may be by hand, machine, chemical or photo-chemical techniques. Where copper is used for plating an initial copper flash may be given in an alkaline cyanide medium. In an example the electro-polishing medium contains H 2 SO 4 15%, H 3 PO 4 65% and H 2 CrO 4 6%, the copper flash contains Cu(CN) 2 , NaCN, Na 2 CO 3 and NaOH, the copper plating bath contains CuSO 4 , H 2 SO 4 and chloride ions and a chromium plating bath contains H 2 Cr 4 and H 2 SO 4 . |
