Patent Application
20180015765
The present invention relates to a gravure printing roll.
At present, when prescribing drugs at domestic hospitals or pharmacies, pharmacists prescribe the drugs in accordance with prescriptions issued by doctors. In order to prevent a prescribing error, a plurality of pharmacists check if a kind of drug and its quantity they are about to prescribe to a patient are identical with the kind of drug and its quantity described in the prescription.
However, it is difficult to prevent human errors completely even if checking is performed by a plurality of pharmacists. Thus, measures to prevent prescribing errors have been demanded. In view of this, it is obliged to print a bar code on a rear surface of a PTP packaging body, whereby the use of such a bar code is expected to prevent prescribing errors.
In general, 10 or 12 tablets are stored in a single PTP packaging body. If the number of tablets prescribed to a patient corresponds to a multiple, such as twice or triple, of the number of the tablets stored in the PTP packaging body, a plurality of PTP packaging bodies can be simply prescribed to the patient. In such a case, the bar code labeled on the PTP packaging body can be utilized.
If the number of tablets prescribed to a patient does not correspond to a multiple of the number of the tablets stored in the PTP packaging body, on the other hand, the drug is prescribed to the patient after the PTP packaging body is divided. In general, only one bar code is printed on a PTP packaging body. Therefore, if the PTP packaging body is divided, the divided PTP packaging body often has no bar code. Thus, the bar code cannot be used to prevent prescribing errors.
Thus, in order to solve the above-described problem arising when a PTP packaging body is divided, it is contemplated that a bar code is printed on each of areas corresponding to tablet storing parts in a sealing film of the PTP packaging body.
Gravure printing is typically employed to print a bar code on a PTP packaging body. The gravure printing is a printing method to perform printing on a printing substrate by feeding an ink to cells provided on a surface of a gravure printing roll and transferring the ink to the printing substrate.
Patent Literature 1 proposes a halftone gravure printing plate in which a crossing angle between a right oblique array direction and a left oblique array direction of cells from highlight to shadow is 90 degrees and a crossing angle between the right oblique array direction and a doctor contact line direction has a tilt smaller or larger than 45 degrees by a predetermined angle. In this halftone gravure printing plate, as a result of a laser exposure scan, a cell with a dot percent less than 31% has a shape elongated in a direction perpendicular to the doctor contact line direction, a cell with a dot percent equal to 56% is a rhombus cell, and a cell with a dot percent in a range from 31% to less than 56% has a hollowed rhombus ring shape having an outer peripheral profile same as that of the aforementioned cell with 56%. One of diagonal directions in the aforementioned cells from 31% to 56% is set to be the direction perpendicular to the doctor contact line direction and gradually increasing according to tint gradation levels.
Patent Literature 1: Japanese Patent No. 3184707
Printing a bar code on each of areas corresponding to tablet storing parts in a sealing film of a PTP packaging body, however, significantly changes the appearance of the PTP packaging body. Such a change in the appearance of the PTP packaging body leads to other problems such as making patients worried that the prescribed drug may be wrong and possibly inducing the prescribing errors of the drug by pharmacists. Thus, a printing technique by which printing can be performed on a PTP packaging body without changing the appearance of the PTP packaging body as much as possible has been demanded.
The object of the above-described halftone gravure printing plate is to eliminate moiré in color printing and improve the tint gradation levels. Thus, an ink fed into each of the cells in the halftone gravure printing plate is not fixed on a printing substrate independently from one another after being transferred to the printing substrate, but the ink transferred from each cell is joined and integrated with one another to form a desired picture. Therefore, the above-described halftone gravure printing plate cannot be employed for the printing of fine dots with a size close to that of the cells.
The present invention provides a gravure printing roll that enables printing of fine dots with a size close to that of cells and enables printing on a print subject such as a printing substrate without changing the appearance of the print subject.
A gravure printing roll of the present invention includes: a gravure printing roll body; and cells formed in a peripheral surface of the gravure printing roll body, wherein the cells each have an opening with a ratio between a dimension in a circumferential direction of the gravure printing roll body and a dimension in an axial center direction of the gravure printing roll body (dimension in the circumferential direction/dimension in the axial center direction) being 1.15 to 7, and have an opening area of 3900 μm2 or smaller.
In other words, the gravure printing roll of the present invention is a gravure printing roll including cells formed in a peripheral surface of a gravure printing roll body, and is characterized in that the cell has an opening with a dimension ratio between a circumferential direction and an axial center direction of the gravure printing roll body (circumferential direction/axial center direction) being 1.15 to 7, and has an opening area of 3900 μm2 or smaller.
In the above-described gravure printing roll, the opening of the cell has a rectangular shape.
In the above-described gravure printing roll, the cell has a depth of 6 to 25 μm.
The thus configured gravure printing roll of the present invention enables the ink fed to each of the cells to be smoothly transferred and fixed to a print subject independently from one another. The use of the gravure printing roll of the present invention thus enables the printing of fine dots on a print subject.
An example of a gravure printing roll of the present invention will be described with reference to the drawings. As shown in
The cells 2 having openings are formed in a peripheral surface 11 of the gravure printing roll body 1. More specifically, the cells 2 having openings are formed all over a surface part 12 of the gravure printing roll body 1.
As shown in
As shown in
The circumferential direction X of the gravure printing roll body 1 refers to a rotational direction, i.e., print direction of the gravure printing roll body 1. The axial center direction Y of the gravure printing roll body 1 refers to a direction perpendicular to the rotational direction of the gravure printing roll body 1.
When two straight lines L1, L1 intersecting or in contact with the cell 2 and parallel to the axial center direction of the gravure printing roll body 1 are drawn, the dimension of the cell in the circumferential direction of the gravure printing roll body 1 refers to a maximum distance W1 between the two straight lines L1, L1.
When two straight lines L2, L2 intersecting or in contact with the cell 2 and parallel to the circumferential direction of the gravure printing roll body 1 are drawn, the dimension of the cell in the axial center direction of the gravure printing roll body 1 refers to a maximum distance W2 between the two straight lines L2, L2.
The shape of the opening of the cell 2 is not limited to a particular shape so long as the above-described dimension ratio and an opening area to be described later fall within respective predetermined ranges. Examples of the shape of the opening include polygons, such as a triangle (for example,
Although the mechanism that enables the ink in the cell 2 to be smoothly transferred and fixed to the print subject by setting the dimension ratio of the cell within the above-described range has not been made clear, the following is thought to be the reason.
As shown in
More specifically, the print subject B is first in contact with the openings of the cells 2. As shown in
The opening area of the cell 2 in the gravure printing roll A is 3900 μm2 or smaller, preferably 3600 μm2 or smaller, more preferably 2500 μm2 or smaller, and particularly preferably 2000 μm2 or smaller. The opening area of the cell 2 set to be 3900 μm2 or smaller enables the printing of fine dots with a diameter of 100 μm or smaller, in particular, fine dots with a diameter of about 20 to 50 μm, which can be hardly identified by human eyes.
The opening area of the cell 2 in the gravure printing roll A is preferably 200 μm2 or greater, more preferably 300 μm2 or greater, and particularly preferably 400 μm2 or greater. The opening area of the cell 2 set to be 200 μm2 or greater enables smoother withdrawal of the ink from the cell 2 and sharp dot printing on the print subject.
The depth of the cell 2 in the gravure printing roll A is preferably 6 to 25 μm, and more preferably 10 to 25 μm. The depth of the cell 2 set within the aforementioned range enables smoother withdrawal of the ink from the cell 2 and sharp dot printing on the print subject. Note that the depth of the cell 2 refers to the depth of the deepest portion.
The interval between the cells 2 adjacent to each other in the gravure printing roll A may be any distance as long as the ink parts withdrawn from the respective cells 2 and transferred to the print subject are prevented from being merged and integrated with each other on the print subject. Specifically, the interval between the cells 2 adjacent to each other in the gravure printing roll A is preferably 50 to 1000 μm, more preferably 100 to 800 μm, and particularly preferably 150 to 500 μm.
Note that cells adjacent to each other and an interval therebetween are defined in the following manner. As shown in
A straight line L3 connecting between the cell centers S, S of cells 21 and 22 is drawn. As shown in
The interval between the cells adjacent to each other refers to a distance W3 between points R1 and R2 at which the straight line L3 intersects with the opening edges of the cells 21 and 22.
The formation density of the cells 2 in the gravure printing roll A is preferably 25 cells/mm2 or smaller, more preferably 10 cells/mm2 or smaller. The formation density of the cells 2 set within the aforementioned range enables the ink parts withdrawn from the respective cells in the gravure printing roll A and transferred onto the print subject to be transferred and fixed onto the print subject independently without being merged with one another. Thus, sharp dots can be printed on the print subject.
A method for manufacturing the gravure printing roll A will be described next. The gravure printing roll A can be manufactured by known manufacturing methods.
The gravure printing roll body 1 described above is typically made of a metal such as iron or aluminum. The surface of the gravure printing roll body 1 includes a plating layer (surface layer) made of copper, for example. The cells 2 are then formed on the surface of the plating layer in the gravure printing roll body 1 by a chemical method or a mechanical method. In this manner, the gravure printing roll A can be manufactured. Note that the surface of the plating layer is subjected to chrome plating, for example, after the formation of the cells 2 in the plating layer of the gravure printing roll body 1.
As a method for forming cells by a chemical method, the surface of the plating layer of the gravure printing roll body 1 is subjected to mirror polishing, and then a photosensitizer is applied to the surface of the plating layer (surface layer). After the photosensitizer is cured so as to form a negative type of a cell pattern (dot pattern), uncured part of the photosensitizer is removed. The portion of the plating layer uncovered by the photosensitizer is subjected to etching by an etching solution so as to form recesses. In this manner, the cells can be formed.
Alternatively, as a method for forming cells by a mechanical method, for example, the plating layer (surface layer) of the gravure printing roll body 1 is subjected to mirror polishing. Thereafter, the surface of the plating layer is subjected to engraving with a diamond needle called a stylus so as to form recesses. In this manner, the cells can be formed.
A procedure to perform dot printing on a print subject with the above-described gravure printing roll A will be described next. First, a gravure printer employed in a gravure printing method will be described. In
Furthermore, the back-up roll 3 is disposed above the gravure printing roll A. The gravure printing roll A and the back-up roll 3 are configured to sandwich and press the print subject B by their surfaces facing each other.
The print subject B is not limited to a particular print subject. Examples of the print subject B include a laminated sheet including a metal foil (for example, an aluminum foil or the like) and a synthetic resin film integrally laminated on the metal foil, and a laminated sheet including a metal foil (for example, an aluminum foil or the like) and a print layer formed on a surface of the metal foil.
Furthermore, the ink C is fed into the application liquid pan 4. A lower part of the gravure printing roll A is immersed in the ink C in the application liquid pan 4. Along with the clockwise rotation of the gravure printing roll A in
Thereafter, the elongated print subject B is continuously fed between the facing surfaces of the gravure printing roll A and the back-up roll 3. By pressing the print subject B from the both sides thereof by the gravure printing roll A and the back-up roll 3, the ink C held in each of the cells 2 is transferred onto the print subject B. The ink C is then dried. In this manner, dot printing can be performed on the print subject B.
The ink transferred onto the print subject B is fixed independently from one another without being merged and integrated with one another on the print subject B. Thus, dots each having an area close to the opening area of the cell in the gravure printing roll A are printed on the print subject B.
The ink fed into the cells 2 of the gravure printing roll A is reliably transferred onto the print subject B. Thus, a dot pattern with no unprinted portions is beautifully printed on the print subject B.
Since the dots printed on the print subject each have a very small diameter of 100 μm or smaller, such dots can be hardly identified by human eyes. Note that the diameter of a dot refers to the diameter of a perfect circle with the minimum diameter capable of surrounding the dot.
Therefore, the above-described gravure printing roll A enables dot printing on a print subject without changing the appearance thereof. For example, the gravure printing roll A can be used to print dots on a surface of a drug packaging body (for example, a PTP (press through pack) packaging body, a pouched packaging body, an SP (strip package) packaging body) without changing the appearance thereof. In the case of the PTP packaging body, for example, dots can be printed on the entire outer surface of a sealing film without changing the appearance of the sealing film. A drug code is configured by a plurality of dots, and arrangement patterns of dots are varied to correspond to respective drugs. With a dot arrangement pattern corresponding to a drug stored in a drug packaging body, a plurality of dots are printed on the outer surface of the drug packaging body with the gravure printing roll A. In this manner, a drug code corresponding to a drug stored in a drug packaging body can be printed on the outer surface of the packaging body without changing the appearance of the packaging body. By reading the drug code with a known reader, the drug stored in the packaging body can be checked.
While the present invention will be described more specifically by way of examples, the present invention is not limited thereto.
Gravure printing rolls A each including a huge number of cells 2, each of which had an opening of a rectangular or square shape, formed in a peripheral surface 11 (surface part 12) of a gravure printing roll body 1 were prepared. The corners of the opening of the cell were all formed in an arc shape. The cell 2 included: a bottom surface 2a formed in a concave arc shape in cross section; and a peripheral wall part 2b gradually extending outward from a peripheral edge of the bottom surface 2a toward the peripheral surface of the gravure printing roll body 1. The bottom surface 2a smoothly connected with the peripheral wall part 2b by intermediary of a concave arc part 2c. The bottom surface 2a had a plane rectangle or square shape. When the opening of the cell 2 and the bottom surface 2a each had a rectangular shape, the long side of the rectangle was positioned along the circumferential direction X of the gravure printing roll body 1. When the opening of the cell 2 and the bottom surface 2a each had a square shape, two sides opposed to each other among the sides of the square were positioned along the circumferential direction X of the gravure printing roll body 1. Dimensions of the openings of the cells in the circumferential direction X and in the axial center direction Y of the gravure printing roll bodies as well as depths thereof were as shown in Table 1. Opening areas of the cells were as shown in Table 1. Intervals between adjacent cells were as shown in Table 1. Formation densities of the cells were as shown in Table 1.
Gravure printing was performed with the gravure printer shown in
Ink (manufactured by Fuji Ink Corporation, under the trade name of “MBA Black Ink”) C was fed into the application liquid pan 4. Along with the clockwise rotation of the gravure printing roll A in
Thereafter, the elongated laminated sheet B was continuously fed between the facing surfaces of the gravure printing roll A and the back-up roll 3. By pressing the laminated sheet B from the both sides thereof by the gravure printing roll A and the back-up roll 3, the ink C held in the cells 2 was transferred onto the laminated sheet B. The ink C was then dried. In this manner, dot printing was performed on the laminated sheet B. The laminated sheet B was fed between the facing surfaces of the gravure printing roll A and the back-up roll 3 so that the surface of the laminated sheet B applied with the white ink was positioned closer to the gravure printing roll A.
A gravure printing roll A including a huge number of cells, each of which had an opening of an isosceles triangular shape elongated in the circumferential direction of a gravure printing roll body, formed in a peripheral surface 11 (surface part 12) of the gravure printing roll body 1 was prepared. The cell 2 included: a bottom surface 2a formed in a concave arc shape in cross section; and a peripheral wall part 2b gradually extending outward from a peripheral edge of the bottom surface 2a toward the peripheral surface of the gravure printing roll body 1. The bottom surface 2a smoothly connected with the peripheral wall part 2b by intermediary of a concave arc part 2c. The bottom surface 2a had an isosceles triangular shape. The base of the isosceles triangle was positioned along the axial center direction Y of the gravure printing roll body 1. The dimensions of the opening of the cell in the circumferential direction and the axial center direction of the gravure printing roll body as well as the depth thereof were as shown in Table 1. The opening area of the cell was as shown in Table 1. The interval between adjacent cells was as shown in Table 1. The formation density of the cells was as shown in Table 1.
Dot printing was performed on a print subject in the same manner as that in Example 1 except that the above-described gravure printing roll A was employed. The cells were configured such that the vertex of the isosceles triangle, which was the shape of the opening of the cell, was positioned on the leading side in the rotational direction of the gravure printing roll A.
In each of Examples, the ink transferred onto the laminated sheet B was fixed independently from one another without being merged and integrated with one another on the laminated sheet B. Dots corresponding to the cells were formed independently from one another on the laminated sheet B.
Fixing rates and dot shapes of the resultant dot print on the laminated sheets were measured in the following manner and their results were shown in Table 1.
A photomicrograph of the dot print on the laminated sheet was taken at a 200-fold magnification. Ten measuring zones each in the shape of a square with a side of 2 mm were determined in arbitrary portions on the photomicrograph. The number of dots present in each measuring zone was counted. In each measuring zone, the fixing rate was calculated in accordance with the following formula. The arithmetic mean value of the fixing rates in the measuring zones was calculated. Such an arithmetic mean value was employed as a fixing rate. Note that dots partially present in the measuring zones were excluded. In Comparative Example 2, the ink broke off during the separation of the ink from the cell. Thus, accurate dot printing was unable to be performed. Since the number of printed dots was greater than the number of the cells in the gravure printing roll, the fixing rate was over 100%.
Fixing rate (%)=100×(the number of dots within a measuring zone)/(the number of cells formed in a gravure printing roll per 4 mm2)
A photomicrograph of the dot print on the laminated sheet was taken at a 200-fold magnification. A measuring zone in the shape of a square with a side of 1 cm was determined in an arbitrary portion on the photomicrograph. Dimensions of each dot in the measuring zone in the circumferential direction and the axial center direction of the gravure printing roll body were measured. The arithmetic mean value of the dimensions of the dots in the circumferential direction and the arithmetic mean value of the dimensions of the dots in the axial center direction were calculated. Such arithmetic mean values were shown in Table 1. Note that dots partially present in the measuring zone were excluded.
This application claims the benefit of Japanese Patent Application No. 2015-22715, filed on Feb. 6, 2015, the disclosure of which is hereby incorporated in its entirety by reference.
The gravure printing roll of the present invention can print dots hardly identifiable by human eyes without producing unprinted portions. Thus, a dot pattern can be sharply printed on a print subject without changing the appearance thereof. Therefore, the gravure printing roll of the present invention can be preferably used to print a dot pattern on a surface of a print subject, such as a drug packaging body, for which a change in its appearance is unfavorable.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-022715 | Feb 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/053227 | 2/3/2016 | WO | 00 |
