Abstract
The embossing device for fine embossing of packaging material has a set of embossing rolls with female embossing and male embossing rolls, in each case the structural elements (ML1) of the female embossing roll (M1) and the structural elements (PL1) of the male embossing rolls (P1) being assigned to each other, and the structural elements of one of the rolls being produced independently of the structural elements of the other rolls. At least one structural element (ML1; PL1) of at least one roll (M1, P1) is provided on its bottom surface (B1) and/or surface (S1) and/or side surfaces and/or in its immediate surroundings with light-scattering elements (DM1, D1), the height (H) of which is 10 μm to 150 μm. As a result of the use of light-scattering elements with small dimensions, the contrast of the structural elements can be increased substantially, by which means the overall aesthetic image is improved considerably.
Claims
1. An embossing device for fine embossing of packaging material to produce contrast-enhanced features with a set of embossing rolls including a female embossing roll and a male embossing roll, structural elements of the female embossing roll and structural elements of the male embossing roll assigned to each other, wherein a structural element of an embossing roll from the set of embossing rolls includes light-scattering elements, the light-scattering elements arranged to form a matrix of protrusions with individual protrusions arranged in two different directions on at least one of a bottom surface, a side surface, a plane, and an immediate surrounding of the structural element, a height HK of the protrusions being in a range between 10 μm and 80 μm, having a period of adjacent protrusions between 80 μm and 200 μm in the two different directions, and the protrusions having a foot width of at least 10 μm.
2. The embossing device according to claim 1, wherein the protrusions include pyramids with a square base.
3. The embossing device according to claim 1, wherein the protrusions include pyramids with a rectangular base, are conically-shaped, are half-round-shaped, or half-moon-shaped.
4. The embossing device according to claim 1, wherein the light-scattering elements are arranged on a lower plane, central plane, or upper side of a surface of the structural element of the male embossing roll, and the associated structural element of the female embossing roll includes no light-scattering elements.
5. The embossing device according to claim 1, wherein the light-scattering elements are arranged on a base of the structural element of the female embossing roll, and the associated structural element of the male embossing roll has no light-scattering elements.
6. The embossing device according to claim 1, wherein the light-scattering elements are arranged both on a base of the structural element of the female embossing roll and on a corresponding surface of the structural element of the male embossing roll.
7. The embossing device according to claim 1, wherein the immediate surrounding of the structural elements are provided with light-scattering elements.
8. The embossing device according to claim 1, wherein the depth or height of the structural elements is 25 μm to 400 μm.
9. The embossing device according to claim 1, wherein the light-scattering elements cover an entire surface of at least one of the bottom surface, the side surface, the plane, and the immediate surrounding of the structural element.
10. The embossing device according to claim 1, wherein a surface roughness of at least one of the bottom surface, the side surface, the plane, and the immediate surrounding of the structural element without the light-scattering elements is between 3 μm and 5 μm.
11. The embossing device according to claim 1, wherein the protrusions include tapered elements with flattened tops.
12. The embossing device according to claim 1, wherein the height HK follows the following equation:
HK=RF1+H+RF2, in which RF1 denotes a maximal surface roughness value of surfaces of the female embossing roller, RF2 denotes a maximal surface roughness value of surfaces of the male embossing roller, and H denotes an average height of the protrusions for a corresponding structural element.
13. An embossing device for fine embossing of packaging material to produce contrast-enhanced features with a set of embossing rolls including a female embossing roll and a male embossing roll, structural elements of the female embossing roll and structural elements of the male embossing roll assigned to each other, wherein a structural element of an embossing roll from the set of embossing rolls includes light-scattering elements, the light-scattering elements arranged to form a matrix of protrusions with individual protrusions arranged in two different directions on at least one of a bottom surface, a side surface, a plane, and an immediate surrounding of the structural element, a height HG of the protrusions being in a range between 80 μm and 150 μm, having a period of adjacent protrusions between 200 μm and 450 μm in the two different directions, and the protrusions having a foot width of at least 10 μm.
14. The embossing device according to claim 13, wherein the light-scattering elements cover an entire surface of at least one of the bottom surface, the side surface, the plane, and the immediate surrounding of the structural element.
15. The embossing device according to claim 13, wherein the depth or height of the structural elements is 25 μm to 400 μm.
16. The embossing device according to claim 13, wherein a surface roughness of at least one of the bottom surface, the side surface, the plane, and the immediate surrounding of the structural element without the light-scattering elements is between 3 μm and 5 μm.
17. The embossing device according to claim 13, wherein the protrusions include tapered elements with flattened tops.
18. The embossing device according to claim 13, wherein the height HG follows the following equation:
HG=RF1+H+RF2, in which RF1 denotes a maximal surface roughness value of surfaces of the female embossing roller, RF2 denotes a maximal surface roughness value of surfaces of the male embossing roller, and H denotes an average height of the protrusions for a corresponding structural element.
19. The embossing device according to claim 13, wherein the protrusions include pyramids with a square base.
20. The embossing device according to claim 13, wherein the protrusions include pyramids with a rectangular base, are conically-shaped, are half-round-shaped, or half-moon-shaped.
Description
(1) The invention will be explained in more detail below by using drawings of exemplary embodiments, in which:
(2) FIG. 1 shows, schematically, an embossing device having a set of embossing rolls with a male embossing roll and a female embossing roll, each of which is provided with simple structural elements assigned to each other,
(3) FIG. 1A shows, in a clear illustration from below and above, a variant of the male embossing and associated female embossing structural element from FIG. 1,
(4) FIG. 1B shows a section through two structural elements assigned to each other from FIGS. 1, 1A,
(5) FIG. 2 shows, in a plan view, a male embossing and an associated female embossing structural element,
(6) FIGS. 2A, 2B each show, schematically, a section through the male embossing and female embossing structural element, which each have light-scattering elements arranged on their surface and on the base,
(7) FIG. 3A shows, schematically in a basic sketch, an enlarged section through a male embossing and associated female embossing structural element with light-scattering elements arranged on the base of the female embossing structural element,
(8) FIG. 3B shows, schematically and in a further enlarged section, the influence of the roughness and fabrication tolerances on the light-scattering and structural elements illustrated in FIG. 3A,
(9) FIG. 4 shows a male embossing structural element, the surface of which is provided with light-scattering elements,
(10) FIG. 4A shows a section through the structural element from FIG. 4 and an associated female embossing structural element without light-scattering elements,
(11) FIG. 5 shows a female embossing structural element, the base of which is provided with light-scattering elements,
(12) FIG. 5A shows a section through the structural element from FIG. 5 and an associated male embossing structural element without light-scattering elements,
(13) FIG. 6 shows a male embossing structural element, the surroundings of which are provided with light-scattering elements,
(14) FIG. 6A shows a section through the structural element from FIG. 6 and an associated female embossing structural element without light-scattering elements,
(15) FIG. 7 shows a female embossing structural element, the surroundings of which are provided with light-scattering elements,
(16) FIG. 7A shows a section through the structural element from FIG. 7 and an associated male embossing structural element without light-scattering elements,
(17) FIG. 8 shows a male embossing structural element with side surfaces which are provided with light-scattering elements,
(18) FIG. 8A shows a section through the structural element from FIG. 8 and an associated female embossing structural element without light-scattering elements,
(19) FIG. 9 shows a female embossing structural element with side surfaces which are provided with light-scattering elements,
(20) FIG. 9A shows a section through the structural element from FIG. 9 and an associated male embossing structural element without light-scattering elements,
(21) FIG. 10 shows a two-step male embossing structural element, the surroundings of which are provided with light-scattering elements,
(22) FIG. 10A shows a section through the structural element from FIG. 10 and an associated female embossing structural element without light-scattering elements,
(23) FIG. 11 shows a multi-step male embossing structural element, the surroundings of which are provided with light-scattering elements,
(24) FIG. 11A shows a section through the structural element from FIG. 11 and an associated female embossing structural element without light-scattering elements,
(25) FIG. 12 shows a male embossing structural element, the surroundings of which are provided with light-scattering elements,
(26) FIG. 12A shows a section through the structural element from FIG. 12 and an associated female embossing structural element without light-scattering elements,
(27) FIG. 13 shows a view of a male embossing structural element which is provided with light-scattering elements at some points and the surroundings of which are provided with light-scattering elements,
(28) FIG. 14 shows a further male embossing structural element, which is provided with light-scattering elements at some points,
(29) FIG. 15 shows a male embossing structural element having an elevated star, which is provided with light-scattering elements at some points, and also a series arrangement of light-scattering elements.
(30) FIG. 1 shows, schematically and simplified, a structure of an embossing device having a male embossing roll P1 and a female embossing roll Ml, wherein the female embossing roll is driven by a drive 1. The drive force of the female embossing roll on the male embossing roll is provided via a fine gear mechanism 2, 3. The male embossing roll has some structural elements PL1, which are elevated, and the female embossing roll has recessed structural elements ML1 assigned to the male embossing structural elements. The structures of the female embossing roll are produced independently of the structures of the male embossing roll, for example by means of a laser system, and are therefore non-inversely congruent, by which means they are given improved contrast. In the current prior art, however, other types of production such as engraving, etching or milling are possible.
(31) In the present exemplary embodiment, the surfaces S1 of the male embossing structural elements PL1, the male embossing roll P1 and the bases B1 of the female embossing structural elements ML1 are provided with light-scattering elements D1 and DM1.
(32) FIG. 1A is a clear illustration from below and above. Herein, as a design variant, the structural elements PL1A and ML1A are implemented in the shape of an L and both have the light-scattering elements D1, DM1. FIG. 1B shows a section through two structural elements PL1, ML1 or PL1A, ML1A that are assigned to each other. For simplicity, here the light-scattering elements are designed as square pyramids.
(33) FIG. 2 reveals that the light-scattering elements D2 of the male embossing in this example are flattened pyramids with a square base and a peak spacing E1, a foot width E2 and a height H1. The overall height of the male embossing structural element is H2. The dimensions for the light-scattering elements DM2 of the female embossing structural element ML2, E3, E4, H3, H4 are slightly different from those of the associated male embossing structural element.
(34) As a result of the scattering effect of the light-scattering elements, a matt appearance is produced at these points. The contrast which is produced with the surroundings as a result increases the perception of the logo. The exact shape or dimension of the light-scattering elements is not important within certain limits for the light scattering that is produced, since it lies at the perceptibility limit for the human eye. Thus, the light-scattering elements, instead of being formed in the shape of pyramids with a square, can also be formed with a rectangular or another cross section, or have a conical, half-round or half-moon shape or any other shape.
(35) As emerges from the following figure descriptions, the light-scattering elements can be arranged either only on the male embossing structural elements or only on the female embossing structural elements or on both structural elements or on all or individual side surfaces of the structures or around structures.
(36) In a departure from the idealized representation of the light-scattering elements in FIG. 2, in FIG. 3A the structural elements and light-scattering elements are also illustrated schematically but rather more as actually produced, that is to say taking into account the fabrication tolerances. Here, H1 designates the overall depth of the female embossing structural element ML3, H2.sub.mit the average and H.sub.2max the maximum height of the light-scattering elements N1-N5. In this example, the overall depth H1 varies in a range of 250 μm, and the average height of the light-scattering elements by 50 μm. The overall depth H1 of the female embossing structural element can be between 25 μm and 400 μm. The associated male embossing structural element PL3 is likewise indicated, the height of which is of the same order of magnitude as the depth of the female embossing structural element.
(37) In FIG. 3B, the roughness of the roll steel and the fabrication tolerances are drawn by way of example on an enlarged scale. Here, RF1 and RF2 denote the maximum roughness values of the female embossing and male embossing structural elements in micrometres, which are here assumed to lie between 3 μm and 5 μm. H is the average height of the light-scattering elements N1 to N5, which means the arithmetic means of all five elements assumed here lies around 50 μm. N is an exemplary number of elements, which can be equal or different in the two coordinate directions.
(38) In order that the light-scattering elements meet the requirements, the following conditions must be fulfilled: a) The pressing surfaces on the uppermost surface, see also FIG. 2, must be flat and sufficiently large but not too large, in order to ensure a usable imprint, b) the foot width=cross-sectional diameter at the base of the light-scattering elements, or the side length of the light-scattering elements, must be at least 10 μm. c) the height Hk of the light-scattering elements should be between 10 μm and 80 μm with small step length=pitch or period of the engraving of the light-scattering elements of 80 μm and 200 μm; and d) the height Hg of the light-scattering elements should be between 80 μm and 150 μm with step length between 200 μm and 450 μm; e) the number of light-scattering elements N in regular M/F structures must be at least equal to 2 per structural element, N=[2, 3, 4, . . . ], f) the heights and number of light-scattering elements in free M/F structures is like c) or d) and e), according to design requirement.
(39) Here:
Hk=Rf1+H+Rf2
Hg=Rf1+H+Rf2
(40) H is the average height (=arithmetic mean formed from all heights belonging to N1, N2, . . . ).
(41) FIG. 4 shows a male embossing structural element PL4 on male embossing roll P4 with light-scattering elements D4 on the upper side S4, and FIG. 4A shows a section together with the associated female embossing structural element ML4 in female embossing roll M4 without light-scattering elements.
(42) FIG. 5 shows a female embossing structural element ML5 in female embossing roll M5 with light-scattering elements D5 on the base B5 and, in the section of FIG. 5A, with the associated male embossing structural element PL5 on male embossing roll P5 without light-scattering elements.
(43) FIG. 6 shows a male embossing structural element PL6 on male embossing roll P6 without light-scattering elements with light-scattering elements D6 arranged around the structural element, and, in the section of FIG. 6A, together with the associated female embossing structural element ML6 in female embossing roll M6 without light-scattering elements.
(44) FIG. 7 shows a female embossing structural element ML7 in female embossing roll M7 without light-scattering elements with light-scattering elements DM7 arranged around the structural element and, in the section of FIG. 7A, together with the associated male embossing structural element PL7 on male embossing roll P7 without light-scattering elements.
(45) FIG. 8 shows a male embossing structural element PL8 on male embossing roll P8 with light-scattering elements D8 on some side surfaces and, in the section of FIG. 8A, together with the associated female embossing structural element ML8 in female embossing roll M8 without light-scattering elements.
(46) FIG. 9 shows a female embossing structural element ML9 in female embossing roll M9 with light-scattering elements DM9 on three sides and, in the section of FIG. 9A, together with the associated male embossing structural element PL9 on male embossing roll P9 without light-scattering elements.
(47) FIG. 10 shows a more complex male embossing structural element PL8 on male embossing roll P10. There are no light-scattering elements on the uppermost surface S5 but, on a lower plane S6, light-scattering elements D10 are arranged around the structures of the upper plane. The associated female embossing structural element ML10 in female embossing roll M10 shows no light-scattering elements.
(48) In FIG. 11, the male embossing structural element PL11 on male embossing roll P11 has three planes S7, S8, S9, wherein the uppermost plane S7 has no light-scattering elements, the central plane S8 has light-scattering elements D11, and the lowest plane S9 in turn has no light-scattering elements. The female embossing structural elements ML11 in female embossing roll M11 have no light-scattering elements.
(49) According to FIG. 12, the male embossing structural element PL12 has various logos, wherein the innermost logo L12 can also be coloured. The light-scattering elements D12 are arranged around the structural element PL12.
(50) FIG. 13 shows a further complex male embossing structural element PL13, which has a plurality of planes. The logos contain a circle L13, around the same a plurality of any desired logos, and light-scattering elements D13 arranged around the male embossing structural element.
(51) FIG. 14 shows a further complex male embossing structural element PL14, which has a plurality of logos. In the middle area S10 there is located a square L14, around the same firstly an empty surface, then light-scattering elements D14, followed by an empty border. Adjacent light-scattering elements D14 are likewise arranged around the structural element.
(52) FIG. 15 shows a further male embossing structural element PL15 having an elevated star LST, the arms of which are alternately provided with light-scattering elements D15 and, beside the star, webs R15 with a triangular profile, on which light-scattering elements D16 are arranged. These structures can be seen better in the appended enlargements.
(53) As mentioned further above, for simplicity all the light-scattering elements are shown as pyramids with a square cross section; however trials have shown that a multiplicity of other shapes such as half-round, half-moon-shaped or conical produce similar and, under certain circumstances, even better results.
(54) Female embossing structural elements assigned to the female embossing roll correspond to the male embossing structural elements shown in FIGS. 13 to 15.
