| 摘要 |
A flexible thinwalled sleeve for gravure printing is provided, which, going from inside to outside, essentially consists of (1) a slightly conical layer of nickel to provide mechanical strength, (2) a layer of copper, having the structure of high-gloss copper and which is essentially free of internal stresses, said layer having a cylindrical outer surface, (3) a thin, cylindrical layer of hard copper having a structure suitable for electronic engraving and having a gravure pattern on its outer surface, and if desired, (4) a thin protective layer of chrome. These layers are all firmly adhered to each other and especially the two layers of copper cannot be separated by peeling off. Since a high-gloss copper layer, which is free of internal stresses, has been found unsuitable for electronic engraving, and since the layer of hard copper, suitable for electronic engraving, has been found to have internal stresses, which would be unacceptable in the first layer of copper, the two layers must necessarily be different. |
