Gravure printing units and method for adjusting and/or modifying an ink transfer in a gravure printing method

A gravure printing unit (500) for printing onto substrate (S;

• 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) by which the pattern of recesses (514) provided on the forme cylinder (503) is inked, wherein the forme cylinder (503) can be partially inked from an inking device (511) via a first inking unit cylinder (512), which has recesses (513) in the region of its outer cylindrical surface (518) that correspond to recesses (514) on the forme cylinder (503), and via a second inking unit cylinder (512), which cooperates with the first inking unit cylinder (512) and which comprises ink-transferring elevations (524;
• 524′) or raised areas (522) on its circumference, characterized in that the first inking unit cylinder (512) having the recesses (513) is configured as temperature controllable, in that control means are comprised, via which the temperature at the first inking unit cylinder (512) can be varied in a targeted manner during operation, and in that for adjusting and/or modifying the transfer of ink during operation, a drive means (687;
• 783) is provided, by which a variation of the printing pressure (δ;
• δ1;
• δ2;
• δ3) can be brought about in at least one of the nip points (776;
• 777;
• 778) between two inking unit cylinders and/or printing unit cylinders (512;
• 519;
• 531;
• 503) involved in the transfer of ink between inking device (511) and printing nip (502), while physical contact between said cylinders 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 comprises, in the region of its outer cylindrical surface (518), recesses (513) that correspond to recesses (514) on the forme cylinder (503), and which can be inked in the region of an application point lying on its circumference by an inking device (511), characterized in that in a feed system for supplying the inking device (511) with printing ink (517), a temperature control device (604) is provided, by means of which the temperature of the printing ink (517) to be supplied can be controlled, and in that an ink distribution device (544) having at least one ink distributor (546) is provided, which can be moved back and forth in the axial direction of the first inking unit cylinder (512) by a drive means (581) and which comprises an end (553) that protrudes into an ink supply chamber (516) of the inking device (511), at least in the working position, and/or comprises an ink outlet (619) of a line system provided for feeding in ink, which leads into the ink supply chamber (516).

A method for adjusting and/or modifying a transfer of ink in a printing unit (500) operating according to a gravure printing method and having a forme cylinder (503), which comprises on its circumference an image-forming pattern of recesses (514), and having an inking unit (508) by which the pattern of recesses (514) provided on the forme cylinder (503) is inked, wherein a partial inking of the forme cylinder (503) is carried out from an inking device (511) via a first inking unit cylinder (512), which has recesses (513) in the region of its outer cylindrical surface (518) that correspond to recesses (514) on the forme cylinder (503), and via a second inking unit cylinder (512), which forms a nip point (776) with the first inking unit cylinder (512) and is to be partially inked by the first inking unit cylinder (512), characterized in that for adjusting and/or modifying the transfer of ink from the first to the second inking unit cylinder (512;

• 519), a temperature prevailing at the circumference of the first inking unit cylinder (512) is varied in a targeted manner, and in that for a spontaneous or dynamic modification of ink transfer, the degree of contact existing in the print-on position, i.e. the printing pressure (δ;
• δ1;
• δ2;
• δ3), in at least one of the nip points (776;
• 777;
• 778) between two inking unit cylinders and/or printing unit cylinders (512;
• 519;
• 531;
• 503) involved in the transfer of ink between inking device (511) and printing nip (502), is varied.