KR100725067B1 - Gravure printing method using aquatic gravure ink and gravure printing machine for the same - Google Patents

Abstract

A photogravure printing method and machine for printing films (7) uses a water based ink and avoids customary problems associated with wetting of the plate, bleed, fogging and drying by using a printing drum (3) having between 200 and 400 mesh lines with a depth between 10 and 17 mu . Left-over ink may be reduced by having an ink reservoir formed with a trough (4) into which the inking roller (2) dips the trough (4) being associated with a drip tray (1a) located beneath the printing drum (3). Printing may be improved further by using a doctor blade assembly (5) having two blades of differing resilience. In a modification two inking rollers are used in spaced relationship at the lower part of the printing drum. <IMAGE>

Description

GRAVURE PRINTING METHOD USING AQUATIC GRAVURE INK AND GRAVURE PRINTING MACHINE FOR THE SAME}

1 is an explanatory view of Embodiment 3 configured to reduce the amount of ink remaining by making the ink reservoir of the ink pan as small as possible in a gravure printing machine using aqueous or oily gravure ink;

Fig. 2 is an explanatory diagram of Example 4 configured to solve the problem of poor wetness by changing the position of the finisher roll to the doctor side in a gravure printing machine using aqueous gravure ink;

Fig. 3 is an explanatory diagram of Embodiment 5 which solves the problem of plate blur based on a doctor's contact pressure incompatibility in a gravure printing machine using an aqueous gravure ink;

4 is an explanatory diagram of a detailed structure of a doctor of Example 5;

5 is an explanatory diagram of a conventional ink fan;

6 is an explanatory diagram of a position of a conventional furnishing roll;

7 is an explanatory diagram of a main part and a doctor in a conventional gravure printing press;

8 is an explanatory diagram of a detailed structure of a conventional doctor;

Fig. 9 is an explanatory view of Example 6 in which the position of the finisher roll is disposed on both the doctor knife side and the opposite side in a gravure printing machine using aqueous gravure ink;

10 is an explanatory diagram of Example 8 in which the furnisher rolls are arranged at three places;

11 is an explanatory diagram of a position of a conventional furnishing roll;

12 is an explanatory diagram of Embodiment 9 showing a main part of an aqueous gravure printing machine equipped with a doctor knife device according to the present invention;

13 is an explanatory diagram of a ninth embodiment of a doctor knife device according to the present invention;

14 is an explanatory diagram showing a main part of a conventional planetary gravure printing press;

15 is an explanatory diagram of a conventional doctor knife device.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a gravure printing method performed using aqueous gravure ink, and to devices such as printing drums and prints, ink pans, furnisher rolls, doctors, and the like, which are used in the practice of the printing methods. .

1. In gravure printing, conventionally, an organic solvent type (oil-based) ink is generally used, and the hue of the ink used is different from the single or overlapping printing by the process color in which black, white and black and white are added thereto. If a specific color (hereinafter referred to as `` special color '') required by the customer is toned (also called flesh), or if a large amount of toning is required, the print maker purchases and uses it. have. In addition, the plate is generally characterized by the ink of the organic solvent type in order to satisfy the color performance and gradation (color performance and gradation), mainly the low mesh (bow) Around 175 lines, a deep printing plate (18-30 μ) is used.

For this reason, the gravure printing method using the conventional organic solvent type gravure ink has the following problem.

(1) Since the ink is an organic solvent type, there are problems of a working environment as a printing factory, a problem of disaster prevention, a problem of the global environment due to the release of a solvent, and a problem of a residual solvent when using a film for food packaging.

(2) In the case of the organic solvent ink, the plate has a deep plate core and the mesh is made of a low mesh at the same time because of the fast drying and the low gradation of printing. This is a big factor causing the rise of printing cost.

(3) In the case of current gravure printing, in addition to the single or layered printing by the above process color ink, many features (colors unique to the customer) are used, so that the number of colors and the number of plates increase, and the time loss of the procedure until printing and the color loss In addition, since there is no other use in the case of the feature, the amount of ink remaining is increased and the cost is not only affected, but also disposed of according to the customer's circumstances, and the improvement of resources is also needed.

④ Because of recent market trends due to the variety of varieties, small lot, and short delivery time, the cost problem is becoming more strict, and environmental problems and food hygiene problems are becoming more and more close to social problems. There is a problem that it is difficult to meet the requirements of the.

For the above reason, the printing method using the aqueous gravure ink which does not use the organic solvent attracts attention. However, in this aqueous gravure ink, there is no problem derived from the use of the above-mentioned organic solvents. On the other hand, since it is aqueous, it is an inherent drawback to the plate surface due to poor drying ability and poor re-solubility of the ink to the solvent and surface tension. Plates produced by the same method as current organic solvent inks due to poor wettability of ink not only cause a decrease in printing speed, but also cause problems such as plate blur and poor gradation, and high quality printed materials cannot be obtained. There is a drawback.

2. Next, in the conventional gravure printing machine, since the ink pan 1 is very large, as shown in FIG. 5, a large amount of remaining ink in the ink pan 1 (about 20 kg / pan) If it is a standard color, it can be used immediately for the next printing, but if it is a special color for every regular visitor, it remains in stock until the next order and becomes a factor of significant cost up.

Particularly, as the structure of the printing machine using the aqueous gravure ink, the above structure makes it difficult to reuse the remaining ink due to the plate blur caused by the poor redissolution of the ink, which is an inherent drawback of the aqueous gravure ink. Occurs.

In FIG. 5, 2 is a furnisher roll, 3 is a plate | board copper, 3a is a plate surface, 5 is a doctor, 6 is a pressure drum, and 7 is a film.

Next, in the conventional gravure printing machine, the finisher roll 2 is provided in the opposite side to the doctor 5, as shown in FIG.

For this reason, especially when performing gravure printing using aqueous gravure ink, since the conventional structure is an aqueous gravure ink, the inferior wettability to the board surface of ink which originates in surface tension as an intrinsic drawback arises. In addition, the higher the rotation, the less the ink on the plate surface falls into the ink pan 1, resulting in unevenness of the ink or blurring of the print, resulting in the inability to print well. .

Next, in the conventional gravure printing machine, as for the doctor 5, as shown in FIG. 7, FIG. 8, the length L of the backplate 5b which protrudes from the fixing bracket 5a is 30 m / m. The blade tip L1 of the doctor knife 5c is set to 4 m / m, and by this dimension setting, in the case of oil-based ink, the growth and gradation to the base film are satisfactory.

However, in printing performed using aqueous gravure ink, under the same conditions as in the above-described oil gravure ink, due to a doctor cleavage defect due to poor re-solubility of ink in a water-soluble solvent which is an inherent drawback of aqueous gravure ink, Plate blur occurs, and a problem arises that the conventional doctor structure cannot be used for printing.

In addition, the aqueous gravure ink has a feature that can greatly improve the working environment in printing, compared to the oil gravure ink conventionally used, and the future gravure printing is the direction of the use of the aqueous gravure ink. I think it's a way to go.

3. Next, in the planetary gravure printing machine, as shown in FIG. 11, the finisher roll 2 is arrange | positioned on the opposite side to the doctor knife 5 with respect to the plate cylinder 3, and in the ink pan 1 The ink 4 is pumped up by the single furnishing roll 2 and supplied to the plate surface 3a. In FIG. 11, 6 is pressurization and 7 is a to-be-printed film.

For this reason, in the case of gravure printing using aqueous gravure ink, since the conventional structure is aqueous gravure, it is an inherent drawback that the ink 4 leaks to the plate surface 3a due to surface tension as an inherent drawback. In addition to this, as the high-speed rotation occurs, the ink 4 supplied to the plate surface 3a falls on the ink pan 1 and becomes non-uniform. As a result, the "printing" or "plate blur" of the ink on the printed matter is caused. And the disadvantage that good printing cannot be performed occurs.

In the case of performing gravure printing using oily gravure ink, the above problem does not occur, but there is a problem such as clogging due to drying of the plate surface 3a after transferring the ink to the film 7. The ink 4 needs to be pumped from the ink pan 1 to the plate 3 quickly, and therefore the finisher roll 2 is disposed on the side opposite to the knife edge 5. However, when the plate 3 is made faster, the ink 4 falls or scatters from the plate surface 3a of the plate 3 due to the centrifugal force and the gravity of the ink 4, so that oily gravure ink is used. Even in this case, there is a limit to speeding up the plate 3 (raising the printing speed).

4. Next, in the planetary gravure printing machine, as shown in FIG. 14, the ink 4 in the ink pan 1 is pumped up to the finisher roll 2, and the excess ink transferred to the plate 3 is transferred. By scraping with one doctor knife 5, a favorable plate surface 3a was formed, and a good printed matter was obtained through the pressing 6 on the base film 7.

As shown in Fig. 15, the doctor knife 5 generally supports the blade tip 5c with the back plate 5b and fastens and fastens it with the fixing tool 5a.

However, in the structure of the conventional doctor knife 5, when gravure printing is carried out using aqueous gravure ink, since it is aqueous ink, the surface of the plate surface 3a due to the large surface tension is large. Doctor cutting failure due to precipitation of undissolved matter on the plate surface 3a due to poor leakage and poor re-solubility of the ink to the solvent occurs, and "printing" or "plate blur" of the ink occurs in the printed matter. A disadvantage arises in that good printing cannot be performed.

In particular, a remarkable drawback occurs in the precipitation of the above undissolved matter in black ink (including carbon) and back ink (including titanium white).

Moreover, in order to solve the said problem, when the doctor pressure with respect to the plate | board 3 is enlarged, it is effective for a short time, but since one side wears of the doctor knife 5 quickly, doctor cutting becomes bad again, In addition to the drawback that "plate blurring" is liable to occur and the work cannot be performed for a long time, not only the plate formed on the plate surface 3a causes the ink to be reduced, but also the reprinting is inevitable. In the use of gravure ink, in the case of the conventional doctor knife use, the printing speed should be lowered.

(Purpose of invention)

The first object of the present invention is an aqueous gravure printing method capable of providing a high quality aqueous gravure printed matter while eliminating problems such as plate blur and gradation defects that occur when performing aqueous gravure printing, and this printing method. It is to provide the printed matter by the board | plate used for implementation of this and this printing method.

Next, the second object of the present invention is to reduce the ink cost by making the remaining ink amount as small as possible in the ink pan of the gravure printing machine using the aqueous or oily gravure ink.

Next, a third object of the present invention is to provide a finisher roll which does not cause a problem of poor wetness even in a high speed gravure printing machine using an aqueous gravure ink.

Next, a fourth object of the present invention is to provide a doctor in which no plate blur occurs in a gravure printing machine using an aqueous gravure ink.

Next, the fifth object of the present invention is to solve the problem of "cutting" and "plate blur" caused by poor wetness in gravure printing performed using an aqueous gravure ink.

Next, the sixth object of the present invention is to improve the printing speed in the above-described conventional gravure printing.

Next, in the seventh aspect of the present invention, when printed using aqueous gravure ink, ink "breaks" or "plate blurs" occur in printed matter due to poor doctor cutting due to poor wettability or poor redissolution. It does not provide a doctor knife device.

(Simple description of the embodiment)

Aqueous gravure ink uses the process color ink which consists of south, red, sulfur, and five colors which added black and white to it independently or superimposes, and produces the target color and hue. These five kinds of process color inks are adjusted by mixing with water or a solvent made of water, alcohol, etc., by adding a resin for aqueous ink as a main component, and adding a pigment or any additive thereto.

In the gravure printing method using an aqueous gravure ink, the plate making technique is important. For example, even if the ink is water-based, in the conventional plate (low mesh around 175 lines, judgment of plate depth 18-30μ), plate printing, pressure contamination, doctor line, plate blur, gradation defect, etc. at printing This occurred a lot, and was not achieved industrially, but the small plate depth was 17 to 200-400 lines, preferably 350 lines, the depth of engraving on a printing plate. If it is used as a plate plated at -10 micrometers, preferably 12-13 micrometers, all the troubles at the time of using the said conventional board | plate will be solved. This is the same in either type.

By the way, with respect to the mesh, when the number of players is less than 200 lines, there is a problem that the dot of the ink coating film is blurred due to the poor dryness of the aqueous ink, and the desired quality cannot be obtained.

When the number of players is more than 400, the dams surrounding the cells of the gravure plate (the concave plate) are cut and the dots of the aqueous ink coating film are not formed. . Moreover, since a halftone becomes small, there exists a problem that a tonal width becomes narrow and a desired quality cannot be obtained.

In addition, when the plate core is deeper than 17 mu, the blockage occurs because of poor re-dissolution of the aqueous ink with respect to the aqueous solvent. In addition, due to poor drying of the aqueous ink, not only the printing speed is lowered, but also letters and hue are blurred, and the desired quality cannot be obtained. Moreover, there is a problem such as cost up because the amount of ink used increases.

In addition, when the plate core is shallower than 10 mu, surface unevenness occurs on the plate-making, so there is a variation in the color tone of printing, and thus the desired quality cannot be obtained. Further, since the ink coating film is thin, there is a problem that color density cannot be obtained.

Moreover, although the above description is a single or overlapping printing technique of the process color ink, it is also possible to use the aqueous gravure ink of the color tone in combination with this process color in part or all of the printing, and Engraving in the case of using an aqueous gravure ink is the same method.

(Example 1)

Based on 20 µl biaxially oriented polypropylene film, a commercially available aqueous ink and water / ethanol / isopropyl alcohol are used as a diluent of 50/30/20%. The two primary colors of black, white, and two colors of candle, ink, red, and yellow were prepared, and the gravure printing was carried out with seven colors and seven plates by making 350 lines of bows and 13 microns by laser method. As a result, the obtained print is free from obstacles such as blur, and a high quality printed product can be obtained.

(Comparative Example 1)

Based on 12μ biaxially stretched polyester film, a commercially available aqueous ink and water / ethanol / isopropyl alcohol are used to print a cup viscosity # 3-16 seconds using a diluent of 50/30/20%. Three primary colors of ink, male, red, and yellow plus black, white, and two features were contrasted, and a plate of 175 lines of bows and a 18-μm plate by a laser method was produced by printing. As a result, since the ink is aqueous and has a deep plate core, first, the printing speed is reduced (70 m / min) due to poor drying, and since the mesh of the plate is rough, color gradation cannot be obtained, Since the re-dissolvability of the Korean ink and the surface tension of the aqueous ink and the like are inferior to those of the oily, problems such as plate blur occur, and a printed product of desired quality could not be obtained.

(Example 2)

Based on 15μ of biaxially stretched nylon film, the water-based ink and the water / ethanol / isopropyl alcohol, which are colored, have a printing viscosity of 50 ~ 30/20% diluent. Was adjusted, and printing was performed using a plate plated with a bow 350 lines and a plate core 13 mu by a laser system. As a result, there was no obstacle such as plate blur, and a printed matter with high quality features was obtained, and the gradation of color and reproducibility of fine characters at this time were obtained.

(Comparative Example 2)

Based on 15μ of biaxially stretched nylon film, the printing viscosity is reduced to 50 ~ 30/20% of water, ethanol, isopropyl alcohol, and water / ethanol / isopropyl alcohol. The ink was adjusted and printing was performed using a plate plated with a foreline 175 lines and a plate core 18 mu by a laser system. As a result, problems such as plate blur occurred, and a printed matter of desired quality could not be obtained.

As mentioned above, it turns out that practical gravure printing is possible without giving a problem, such as plate blur, by giving specific conditions to plate making technology from Example 1, 2 and Comparative Examples 1, 2 mentioned above.

(Example 3)

This embodiment is explained in detail based on FIG. 1 shows a plate copper serving as a main part of a gravure printing machine, an ink pan for collecting gravure ink for printing, a furnisher roll for transferring printing ink from the ink pan to the plate surface, and a blade tip contacting the plate surface. It is a figure which saw the doctor which scrapes off excess ink from a board surface, and the pressure which presses a film on a board surface from the side.

In Fig. 1, 1 is an ink fan, and the ink fan 1 of the present embodiment forms a portion where the finisher roll 2 is located at a deep bottom, which is an ink reservoir 4, and a plate copper. The portion where 3 is located is formed with a shallow bottom 1a that is enough to pick up the ink dropped from the plate 3, and the shallow bottom 1a is inclined downward toward the ink reservoir 4 side. The ink for printing does not collect in the part of this shallow bottom 1a.

In the ink fan 1 of the present embodiment, ink for printing is always collected only in the ink reservoir 4 portion, and this ink is applied to the plate surface 3a of the plate 3 through the finisher roll 2, Only the excess ink in the doctor 5 is scraped off the plate surface and provided for printing.

(Example 4)

This embodiment is explained in detail based on FIG. Fig. 2 shows an ink pan for collecting the printing plate and the printing ink, which are the main parts of the gravure printing machine, and a finisher roll for transferring printing ink from the ink pan to the printing plate side and applying the blade to the plate surface. It is a figure which looked at the doctor which scrapes off ink, and the pressure which presses a film to a board surface from the side.

In Fig. 2, 1 is an ink fan, and the ink fan 1 of this embodiment forms a configuration in which the ink reservoir 4 is formed on the side where the doctor 5 is located, and the plate is driven from the ink reservoir 4. The finisher roll 2 which apply | coats printing ink to the board surface 3a of (3) is also located in the doctor 5 side.

Since the finisher roll 2 of this embodiment is located on the side of the doctor 5, the centrifugal force acting upward acts on the ink applied from the finisher roll 2 to the plate surface 3a of the plate cylinder 3, and therefore, at the time of high speed rotation. In the case of the water-based gravure ink having a large surface tension, it does not fall to the ink pan 1 side, and therefore, a wet defect does not occur.

(Example 5)

The details of this embodiment will be described with reference to Figs. 3 and 4. Fig. 3 shows a plate copper which is a main part of a gravure printing machine, an ink fan for collecting ink for printing, a finisher roll for transferring printing ink from the ink pan to the platen surface, and a blade surface in contact with the blade surface. It is a figure which looked at the doctor which scrapes off excess ink, and the pressure which presses a film to a board surface from the side. .

In FIG. 3, 1 is an ink pan, and the ink pan 1 of this embodiment forms a portion where the finisher roll 2 is located deeply, making it an ink reservoir 4, and a portion where the plate 3 is located. The bottom plate 1a is formed to have a shallow bottom 1a enough to pick up the ink dropped from the plate 3, and the shallow bottom 1a is provided with an inclined slope toward the ink reservoir 4 side. It is a structure that does not collect in the shallow bottom part 1a.

5 is a doctor, and as for the doctor 5 of this embodiment, as shown in FIG. 4, the length L of the back plate 5b which protrudes from the fixing bracket 5a is 25 m / m, and this back plate 5b is shown. The length L1 of the blade edge | tip of the doctor knife 5c which protrudes from the front end of is 3.5 m / m.

Further, in the doctor 5, when the length L of the back plate 5b becomes 27 m / m or more, the tip of the blade of the doctor knife 5c is not pressed, and ink scraping is insufficient. When the pressure is 22 m / m or less, the pressure is excessively exerted, which adversely affects the plate surface 3a, such as friction. Therefore, the length L of the back plate 5b is 27 m / m or less, 22 m / m or more, preferably 25 m / m.

Similarly, when the length L1 of the blade tip of the doctor knife 5c becomes 3.7 m / m or more, the scraping of ink becomes insufficient, and when it becomes 3.2 m / m or less, adverse effects such as friction appear on the plate surface 3a. Therefore, L1 is 3.7 m / m or less, 3.2 m / m or more, preferably 3.5 m / m.

(Comparative Example 3)

The comparative example of the doctor 5 of Example 5 is demonstrated next. In the comparison target doctor, the length L of the back plate 5b shown in FIG. 8 is 35 m / m, and the blade length L1 of the doctor knife 5c is 6.5 m / m, for oil ink.

Using 15 microns of biaxially stretched nylon film as a base material, a plate of 350 lines of lead and 13 microns by a laser method was produced, and six colors were divided into five plates using commercially available aqueous gravure ink M, red, yellow, black, and white. In the case of printing, when comparing the present example with the conventional example shown in Fig. 8 as the dimensional condition of the doctor 5, the latter causes plate blur due to poor doctor cutting in each of the colors. In the former, namely, in the case of the doctor 5 according to the present invention, the doctor cut was good in all colors, and there was no plate blur, and a good print film was obtained.

(Example 6)

An embodiment of the present invention will be described in detail with reference to FIG. Reference numeral 1 denotes an ink fan, in which the ink fan 1 is filled with an aqueous ink 4, and the plate surface 3a of the plate 3 is provided with a finisher roll disposed on the opposite side of the doctor knife 5. The ink 4 is spun up and supplied (coated) by 2) and the finisher roll 2a disposed on the doctor knife 5 side. In the figure, 6 is pressurization and 7 is a film (printed object).

When the two finisher rolls 2 and 2a are arranged, the ink 4 is first supplied to the platen 3 by the finisher roll 2 opposite to the knife edge 5, and then the finisher roll 2a is provided. Since the ink is supplied from the ink, the adhesion of the ink 4 to the plate surface 3a is good, and the ink 4 does not scatter (fall) even at a high speed.

Experimental Example 1

This Experimental Example 1 used the furnisher roll apparatus shown in FIG. Printing using a copper plate (plate core 13μ, 350 lines) laser-printed on a biaxially stretched pp film (20μ thick) using an aqueous gravure ink (trade name Aguwa Ecole S, surface tension 24dyne / cm) As a result, good printing was obtained up to a printing work speed of 300 m / min. This is because even if the platen 3 is speeded up by placing the finisher roll 2 on both the doctor knife 5 side and the opposite side, the ink 4 does not fall into the ink pan 1, and thus the aqueous gravure ink does not fall. It is a result of helping the leakage defect to the plate surface 3a which is a fault.

(Comparative Example 4)

The finisher roll apparatus (conventional example) shown in FIG. 11 was used. Printing was performed under the same conditions as in Experimental Example 1. However, the print speed was only good up to 70m / min.

This is because the surface tension of the aqueous gravure ink 4 itself is large, and in addition to the poor wetness to the plate surface 3a, the ink 4 of the plate surface 3a is transferred to the ink pan 1 as the plate copper 3 is accelerated. It is a cause to fall in).

(Example 7)

Embodiments of the present invention are described in detail below.

Experimental Example 2

Printing was carried out under the same conditions as in Experimental Example 1 except that oily gravure ink (trade name NEW LP Spur manufactured by Toyo Ink Corporation, surface tension of 17 dyne / cm) was used as the ink. As a result, even if the printing speed was raised to 350 m / min, good printing was obtained.

(Comparative Example 5)

Using the apparatus in which the finisher roll 2 is arranged only on the opposite side of the knife edge 5 shown in FIG. 11, printing was performed under the same conditions as in Experimental Example 2, that is, ink dropped at a printing speed of 200 m / min or more. Print stains occurred and good printing could not be obtained.

(Example 8)

An embodiment of the present invention is shown in FIG. This embodiment is an example in which the third finisher roll 2b is disposed between the finisher roll 2 and the finisher roll 2a. By adopting this configuration, printing was performed under the same conditions as in Experimental Example 1, that is, good printing was obtained. Furthermore, even if the speed was raised to 320 m / min, no drop of ink was obtained, and good printing was obtained.

(Example 9)

An embodiment of the present invention will be described in detail with reference to Figs. 12 and 13. This embodiment relates to the structure of the doctor knife device according to the present invention. FIG. 12 shows a plate copper 3 serving as a main part of a gravure printing press, an ink fan 1 for collecting an aqueous ink 4, and this ink. The finisher roll 2 placed on the side of the doctor knife 5 which transfers the aqueous ink 4 to the plate surface 3a by the fan 1, and the two blade edges are brought into contact with the plate surface 3a to form a plate surface ( It is the figure which looked at the doctor knife 5 which scrapes off excess ink from 3a, and the pressure cylinder 6 which presses the base film 7 to the board surface 3a.

Further, by placing the finisher roll 2 on the side of the doctor knife 5, there is an advantage that the fall rate of the ink applied to the plate surface 3a can be reduced to prevent wet defects and cope with high-speed rotation.

As shown in Fig. 13, the two-kned doctor knife 5 supports the blade tips 5c ₁ and 5c ₂ with the back plates 5b ₁ and 5b ₂ and fastens and fastens them with the fixing bracket 5a. It is not limited to a structure. For example, the doctor knife 5 may be independent by individual fixing brackets, and a plurality of these may be arranged.

The blade edges 5c ₁ and 5c ₂ can also be arbitrarily selected.

Furthermore, the lengths of the back plates 5b ₁ and 5b ₂ protruding from the fixing bracket 5a and the ends 5c ₁ and 5c ₂ of the blades can be adjusted to arbitrary lengths.

In this embodiment, two blades are set as the dimension conditions of the doctor knife 5 as shown in Fig. 12, and the lengths of the back plates 5b ₁ and 5b ₂ protruding from the fixing bracket 5a in Fig. 13 are set. The lengths of the blade tips 5c ₁ and 5c ₂ protruding from the back plates 5b ₁ and 5b ₂ are respectively 26m / m, 25m / m and 3.5m / m, and the blade tips 5c ₁ and 5c _{2 are} respectively. The interval of was set as 0.8 m / m.

Here, 20 micrometers of biaxially-stretched polypropylene films were produced, and the board | substrate of 350 lines of bows and 13 micrometers by a laser system was produced, and it used commercially available aqueous gravure ink, male, red, yellow, black, and white. Six colors were printed on five plates.

In this printing, the ink of the plate surface 3a is first scraped off by the first blade tip 5c ₂ , and the ink of the plate surface 3a is subsequently scraped off by the second blade tip 5c ₁ , so that a doctor cutting occurs. Without this, good printing could be achieved.

Moreover, the number of doctor knives 5 is two or more, but practically up to three. The position with respect to the pan-dong 3 may be arranged in one place, but two or three blades may be divided and arranged. In the conventional example, the doctor knife 5 is made of stainless steel, but both of them may be made of stainless steel, the first sheet may be made of stainless steel, and the second sheet may be made of another material.

In addition, the first and second knife pressures may be the same, and by setting the first sheet higher and the second sheet lower than the first sheet, the second sheet may be scraped by an action close to wiping off the scraping off from the second sheet.

(Comparative Example 6)

The comparative example at the time of printing using aqueous gravure ink using the doctor knife 5 demonstrated in FIG. 14, FIG. 15 is demonstrated next.

This comparison target doctor knife 5 sets one conventional blade as shown in Fig. 14, and in Fig. 15, the length of the back plate 5b protruding from the fixing bracket 5a is 25 m / m, The length of the blade tip 5c protruding from the plate 5b was 3.5 m / m.

The conditions of this doctor knife 5 are the same as the 1st sheet of Example 9. Here, printing was performed using the same base film, plate, and aqueous gravure ink as in Example.

Table 1 shows a comparative example of the results.

Example Comparative example Plate blur No color was generated even at 20,000m of printing It was more than twice as long as the right substrate. Occurs when printing is 10,000m. Especially in black ink (including carbon) and back ink (including titanium white) Doctor wear It can lower the doctor pressure to 1.5kg, so it can be long run at 20,000m of printing. Since it was one day, it required a doctor pressure of 2kg, so the limit was reached at the time of printing 120,000m. Ink reduction For the same reason, it was possible to run a long run even at 100,000m. Due to the cause of homology, the limit was reached at the printing point of 70,000 m. Print speed It was also good at 150 m / min. 120 m / min limit

As apparent from the above description, according to the present invention, gravure printing of inferior quality is possible as compared with the case of using conventional oil-based ink, by concentrating the devising on the plate making technology for the practical use of the aqueous gravure printing technology. . That is, the problem of gradation at the time of printing due to the drying defect which is an essential defect of the aqueous ink due to the high mesh of the plate, the top plate, the poor re-solubility of the ink to the solvent and the blur of the plate due to the poor moisture of the ink on the plate surface It is possible to solve the problems of quality and productivity such as the problem of.

In addition, the use of aqueous gravure inks can also solve labor problems in the printing plant, disaster prevention problems, environmental problems caused by the release of organic solvents into the air, and problems with residual solvents in food packaging films.
Therefore, according to the present invention, its advantages are particularly great in the field of food packaging and the like based on plastic films.
Next, according to the present invention, since the amount of ink collected in the ink pan can be minimized as necessary, the amount of remaining ink can be reduced from about 20 kg per plate to about 5 kg per plate. As a result, the ink cost can be reduced, the stock cost of the remaining ink, and the resource can be reduced.

Next, according to the present invention, since ink is applied from the finisher roll at the position where the plate surface rotates in the ascending direction, in the use of high surface tension aqueous gravure ink, ink scattering is eliminated, especially during high-speed rotation, No problem of wetness occurs.

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Next, according to the present invention, at the tip of the doctor, the connection pressure to the plate surface is optimized in gravure printing performed using aqueous gravure ink, and the problem of plate blur does not occur.

Furthermore, since the doctor pressure can be reduced, the wear of the doctor knife and the ink reduction of the plate can be reduced, so that the productivity can be improved by matching with the speed of printing.

Next, according to the present invention, ink is well applied to one side by arranging the finisher roll both on the opposite side of the knife edge and the knife edge side, or in addition to the above, and the aqueous surface gravure ink of high surface tension is applied. Even when using, good printing was obtained without wet defect and without "cutting" or "plate blur".

Therefore, according to the present invention, printing using aqueous gravure ink becomes possible and coping with environmental problems becomes possible. In addition, in the use of oil-based gravure ink, the printing speed can be improved.

Claims (12)

In gravure printing presses using aqueous or oily gravure inks, the ink reservoir is formed to a size at which only the finisher roll is to be immersed, and the panto is deviated from the ink reservoir. The structure of the ink pan for gravure printing press. delete delete delete delete delete delete delete delete delete delete delete

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