Method for producing a printed product

Abstract

A method produces a printed product. The method includes transferring a first Fluid onto at least one section of printing stock, applying a second fluid, having a dewetting effect on the first fluid, onto a form configured as a relief printing form or embossing form, and transferring the second fluid to at least some points of the section. In this manner printed products of high quality can be produced.

Claims

1. A method for producing a printed product, which comprises the following steps of: transferring a first fluid onto at least one section of printing stock; applying a second fluid, having a dewetting effect on the first fluid, onto a form configured as a letterpress form or an embossing form; and transferring the second fluid to at least some points of the at least one section.

2. The method according to claim 1, which further comprises transferring the second fluid while the first fluid is not yet or is not yet substantially dried and/or cured.

3. The method according to claim 1, which further comprises pressing or embossing the second fluid into the first fluid under compression.

4. The method according to claim 1, wherein the second fluid touches the printing stock at the points and displaces the first fluid.

5. The method according to claim 1, wherein the second fluid reduces or prevents flowing back of the first fluid at the points.

6. The method according to claim 1, wherein the second fluid structures the first fluid in accordance with a structure of the form.

7. The method according to claim 1, which further comprises transferring the first fluid over an entire area of the section.

8. The method according to claim 1, which further comprises drying and curing the first fluid after a transfer of the second fluid.

9. The method according to claim 1, wherein at least one of the first fluid or the second fluid is a lacquer.

10. The method according to claim 1, which further comprises printing the printing stock before a transfer of the first fluid.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is a flow chart of a preferred embodiment of the method according to the invention;

(2) FIG. 2 is a diagrammatic, side view of a printing press for carrying out the method according to the invention;

(3) FIG. 3 is an illustration showing a transfer of a second fluid; and

(4) FIG. 4 is an illustration showing the prior art.

DETAILED DESCRIPTION OF THE INVENTION

(5) Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a flow chart of a preferred embodiment of the method according to the invention having method steps A to H for producing a printed product 1a from printing stock 1b. The method steps are explained hereafter. In this case, reference is also made to FIG. 2, which shows by way of example a sheet-processing printing press 6 for carrying out the method according to the invention, and also FIG. 3, which in particular shows the transfer of a second fluid (method step F).

(6) In method step A, the printing stock 1b is provided, for example, paper, cardboard, paperboard, plastic film, or metal foil (each preferably as a sheet or alternatively as a web). The provision can preferably take place as a sheet stack in a non-illustrated feeder of the printing press 6. Alternatively, a metal plate can also be provided.

(7) In optional method step B, the printing stock 1b is optionally printed. The printing preferably takes place in at least one printing mechanism 8 of the printing press 6, preferably in four offset printing mechanisms (CMYK printing method). After the printing, drying and/or curing can take place, for example, in a drying mechanism (not shown) directly after the printing mechanism, preferably in a UV drying mechanism.

(8) In method step C, a first fluid 2 and a second fluid 3 are provided. The first fluid is preferably provided as a lacquer and is preferably provided in a first lacquering mechanism 9 of the printing press 6. The second fluid is preferably also provided as a lacquer and is preferably provided in a second lacquering mechanism 14 of the printing press.

(9) The first fluid 2 is preferably provided as a UV-curable lacquer (“UV lacquer”), for example, as the lacquer sold under the name “Saphira U8730”. UV lacquer has the advantage here that it only loses little volume (upon curing) and the structure introduced according to the invention and/or corresponding embossing effects are therefore more distinctive.

(10) The first fluid 2 can be a clear lacquer, a flexographic ink, a metallic lacquer, a lacquer having effect pigments, a fluorescent lacquer, a matte lacquer, or a colored lacquer.

(11) In method step D, the first fluid 2 is transferred onto at least one section 4 of the printing stock 1b. The transfer is preferably performed by the first lacquering mechanism 9 and/or by a first cylinder 10 and a first counter cylinder 11 of the mechanism. The mechanism 9 can be a so-called Anicolor mechanism and the transfer can be performed by a flexographic form. Alternatively, the mechanism can be an offset, gravure, screen, or inkjet mechanism. Furthermore, the first fluid can alternatively be applied via roller coating or spray lacquering.

(12) In FIG. 3, the printing stock 1b having the already transferred first fluid 2 is shown in the middle image. A layer thickness of 2 to 20 μm, particularly preferably of 5 to 10 μm, of the first fluid is preferably created on the printing stock. The first fluid is preferably transferred over the entire area in the section 4. Alternatively, a transfer is performed over only a partial area, for example, in the case of a so-called spot lacquering. After the transfer of the first fluid, the printing stock 1b is conveyed (further) in a transportation direction 7.

(13) In optional method step E, radiation is optionally applied to the first fluid 2. This is preferably performed in at least one drying mechanism 12 of the printing press 6. The quality of the printed product 1a can possibly be improved by the application. For example, an excessively thin lacquer (as the first fluid 2) can be slightly dried and thus can become able to be better formed/embossed. Or, for example, a UV lacquer (as the first fluid) can be slightly heated and thus made more uniform. If such measures are not required, the method can also be carried out in a printing press 6 without drying mechanisms 12.

(14) In method step F, the second fluid 3 is applied to a form 13. In this case, this is preferably a relief printing form, for example, a flexographic form, or an embossing form. The form 13 is preferably accommodated on a second cylinder 15 of a second lacquering mechanism 14 of the printing press 6. In FIG. 3, the form 13 is shown in the top image. It has protrusions 17, which bear the second fluid. The protrusions can be created in accordance with a pattern or image, and/or the form 13 is structured using the protrusions or forms a corresponding relief. The protrusions 17 can be soft and/or elastic, for example, if a flexographic form is used. Alternatively, the protrusions 17 can be hard, preferably in cases in which the counter cylinder is soft and/or the printing stock is compressible.

(15) In method step G, the second fluid 3 (applied to the form 13) is transferred at at least some points 5 of the section 4 to the printing stock 1b. The transfer preferably takes place in a gap between the second cylinder 15 and a second counter cylinder 16. The method step of the transfer is recognizable in the middle and bottom images in FIG. 3. The protrusions 17 of the form 13 penetrate into the first fluid 2 and place the second fluid at the points 5.

(16) The second fluid 3 is preferably transferred while the first fluid 2 is not yet or not yet substantially dried and/or cured and therefore can still be formed. The second fluid is thus preferably transferred through the still “wet” first fluid up to the printing stock.

(17) The second fluid 3 is preferably pressed or embossed under compression into the first fluid 2, wherein the first fluid is preferably displaced, so that the second fluid preferably reaches the printing stock 1b or its surface.

(18) The second fluid 3 preferably prevents or reduces flowing back of the first fluid 2, at least at the points 5. In this way, the layer made of first fluid is preferably structured in accordance with the structure of the form 13 and/or in accordance with the protrusions 17. This structure is advantageously substantially maintained (also in the temporary wet state of the first fluid).

(19) The flowing back of the first fluid 2 is prevented according to the invention in that the second fluid 3 is used which has a dewetting effect on the first fluid. If, for example, “Saphira U8730” is used as the first fluid, a UV-curable lacquer, in particular for flexographic printing, for example, the lacquer sold under the name “Saphira U8780”, can thus be used as the second fluid. The dewetting effect is substantially based on the different surface tensions of the first and the second fluid, wherein the surface tension of the first fluid is selected as greater than that of the second fluid. Examples: “Saphira U8730” has a measured surface tension between 30 and 32 mN/m and “Saphira U8780” of approximately 22 mN/m.

(20) The second fluid 3 can be uncolored or colored and optionally also pigmented. The second fluid can be considered to be a dewetting fluid and/or a stabilization fluid and can be denoted accordingly.

(21) Preferably, a layer thickness of 1 to 5 μm, particularly preferably of 2 to 3 μm, of the second fluid 3 is created on the printing stock 1b.

(22) In FIG. 3, the bottom image shows how the layer made of first fluid 2 is structured by the transfer of the second fluid 3 having a dewetting effect and this structure is maintained. In comparison thereto, it is shown under this in FIG. 4 that an embossing procedure according to the prior art (i.e., without dewetting fluid) only creates a printed product of lower quality due to uncontrolled flowing back.

(23) In method step H, the first fluid 2 is dried or cured after the transfer of the second fluid 3 (after method step G) and in this way the structuring (the “embossed image”) is fixed. This is preferably performed by a dryer 18 during the further transportation of the printing stock 1b (for example, in a delivery unit (not shown in its entirety) of the printing press 6). Thermal drying can be performed (IR and/or hot air) and/or curing can be performed using UV. The second fluid 3 is preferably also dried and/or cured, particularly preferably by means of the same dryer.

(24) When reading the claim language, the following definitions apply. When the claim language recites A and/or B it means A alone, B alone or A and B. When the claim language recites at least one of A and B it means A alone, B alone or A and B. When the claim language recites at least one of A or B it means A alone, B alone or A and B.

LIST OF REFERENCE SIGNS

(25) 1a printed product 1b printing stock 2 first fluid 3 second fluid 4 section 5 points 6 printing press 7 transportation direction 8 printing mechanism 9 first lacquering mechanism 10 first cylinder 11 first counter cylinder 12 drying mechanism(s) 13 form 14 second lacquering mechanism 15 second cylinder 16 second counter cylinder 17 protrusions/structure 18 dryer A-H method steps