Gravure printing units for printing onto substrates by a gravure printing method

A gravure printing unit (500) for printing onto substrate (S) according to a gravure printing method, said gravure printing unit having a forme cylinder (503), which comprises on its circumference an image-forming pattern of recesses (514), and having an inking unit (508) for inking the pattern of recesses (514) provided on the forme cylinder (503), said inking unit comprising a first inking unit cylinder (512), which has, in the region of its outer cylindrical surface (518), recesses (513) that correspond to recesses (514) on the forme cylinder (503), an inking device (511) by means of which the first inking unit cylinder (512) can be inked at an application point located on its circumference, and a second inking unit cylinder (519), which cooperates with the first inking unit cylinder (512) and which has, in the region of its outer cylindrical surface (521), elevations (524;

• 524′) that correspond to recesses (514) on the forme cylinder (503) or raised areas (522), which correspond to areas (523) of the image-forming pattern of recesses (514) on the forme cylinder (503) and which comprise the recesses (514),
• wherein the inking device (511) comprises, on at least the downstream side of the application point in the operating direction of rotation (D) of the inking unit cylinder (512) that comprises the recesses (513), a retaining means (526) configured as a doctor blade, which in the operating position is in physical contact with the outer cylindrical surface (518) of the first inking unit cylinder (512), and by means of which printing ink (517) lying on and/or previously applied to non-engraved regions of the outer cylindrical surface (518) of the first inking unit cylinder (512) can be removed,
• characterized in that the second inking unit cylinder (519) cooperating with the first inking unit cylinder (512) has, in the region of its outer cylindrical surface (521), elevations (524;
• 524″) that correspond to recesses (514) on the forme cylinder (503), or raised areas (522) that correspond to areas (523), which comprise recesses (514), of the image-forming pattern of recesses (514) on the forme cylinder (503), and in that the inking device (511) is mounted, coupled to the first inking unit cylinder (512) that has the recesses (513), in or on a frame (533;
• 538) in such a way that when the first inking unit cylinder (512) is moved radially, the inking device (511) is moved along with it and the radial relative position between inking unit cylinder (512) and retaining means (526) is maintained.

A gravure printing unit (500) for printing onto substrate (S) according to a gravure printing method, said gravure printing unit having a forme cylinder (503), which comprises on its circumference an image-forming pattern of recesses (514), and having an inking unit (508) for inking the pattern of recesses (514) provided on the forme cylinder (503), said inking unit comprising a first inking unit cylinder (512), which has, in the region of its outer cylindrical surface (518), recesses (513) that correspond to recesses (514) on the forme cylinder (503), an inking device (511) by means of which the first inking unit cylinder (512) can be inked at an application point located on its circumference, and a second inking unit cylinder (519), which forms a nip point with the first inking unit cylinder (512), characterized in that

• the second inking unit cylinder (519) comprises, on its outer cylindrical surface (21), elevations (524;
• 524′) that correspond to engravings (514) on the forme cylinder (503), which in the region of their smallest diameter have a maximum width (b524) of 0.6 mm and/or have a width (b513) that is no more than 0.5 mm greater than the width (b514) of a corresponding engraving (514) on the forme cylinder (503) and/or which match individual engravings (514) on the forme cylinder (504) with a width (b513) that is a maximum of ten times greater and/or which individually match engravings (514) on the forme cylinder (503) that are spaced by 1 mm from one another, and/or which second inking unit cylinder comprises on its outer cylindrical surface (21) areas that have at least five non-contiguous elevations (524;
• 524′) over a surface area of 10 cm2 and/or that have two or more non-contiguous elevations (524;
• 524′), each of which is spaced no more than 1,000 μm from an adjacent elevation (524;
• 524′).