| 摘要 |
A method of manufacturing a gravure print roller includes providing a hard surface layer on a cylindrical body, and forming an array of recesses in the hard layer. As described a steel roll bears an A1 coating to which hard silica is applied. The silica is patterned with photoresist and etched to leave recesses which pass into the underlying A1. Both the remaining photoresist and silica are removed to leave indentations in the A1, after which a nitride layer is applied. Anisotropic etching of the nitride leaves only the vertical walls of the pits coated with nitride after which the A1 surface is anodised. The pits are then selectively filled to form the image. This may be by filling all pits and subsequently removing material from selected pits. As shown Fig 5, the finished steel cylinder (11) bears residual A1 (12) covered by A1 oxide (18) in which pits (16) are formed. The walls of the pits are coated with nitride (17a), and selected pits are filled with plastics material (19). <IMAGE> |
