A METHOD FOR OBTAINING A SEAMLESS ENGRAVING CYLINDER FOR PRODUCING SHEETS WITH OPTICAL EFFECTS, AND A PLANT INCLUDING SAID CYLINDER

摘要

Plant for obtaining sheets with optical effects, said sheets (2) receiving the impression of various patterns and/or illustrations (a, b, c, d and e) and receiving a layer of transparent resin (1); the engraving of the resin, by contact and polymerisation, produces the optical effects. In the plant, the application of the resin (1) to the sheet (2) is effected by rotogravure, rotary serigraphy, flexography, offset or other means, directly to the engraving cylinder (4, 4', 4'' or 4''') or on the sheet (2); ultra violet rays (18) are used as polymerising element, optatively with filter (19) for infrared rays, or an electron generator; the engraving and polymerization of the resin (1) are done at the same time and with the use of an engraver cylinder (4, 4', 4'', or 4''') without any seam. The printing means, the engraving means and the polymerization means form a compact assembly (20) arranged in line on a rotary machine (21).