JP5483531B2 - Gravure printing machine using water-based ink - Google Patents

Description

The present invention relates to a gravure printing machine using water-based ink . More specifically, the present invention relates to a wetting defect which becomes a problem when printing using water-based gravure ink, and “fogging of thread-like ink”, “plate fog” and the like resulting from this. The present invention relates to a gravure printing machine using water-based ink that solves the above problem.

  In the case of water-based gravure ink (hereinafter referred to as “water-based ink”) compared to oil-based gravure ink (hereinafter referred to as “oil-based ink”) that has been used in the past, there is a feature that can greatly improve the working environment in printing. Therefore, future gravure printing is likely to go in the direction of using water-based gravure ink.

  However, in a conventional gravure printing machine using oil-based ink, the finisher roll 5 is between the ink pan 1 and the plate cylinder 3 filled with oil-based ink 2 as shown in FIG. Since the peripheral speed is set to 5 to 50% of the peripheral speed of the plate cylinder 3, when this gravure printing machine is used for water-based ink as it is, it becomes water-based ink. Insufficient wetting occurs due to the characteristics (surface tension) of the ink, causing "fogging of thread-like ink" and "plate fog".

  For this reason, in a conventional gravure printing machine, when water-based ink is used as it is, there is a problem that a good printed matter can be obtained only at a printing work speed of up to 70 m / min.

  Therefore, the applicant of the present invention arranges the finisher rolls 5 and 5a on both sides of the plate cylinder 3, as shown in FIG. Further, when the peripheral speed of the finisher rolls 5 and 5a is set to 5 to 50% with respect to the peripheral speed of the plate cylinder 3, as in the case of oil-based ink, high-speed “fading of thread-like ink” and “ Since it was possible to obtain a high-quality printed matter without “plate fog”, a patent application was filed as Japanese Patent Application No. 2000-14712 (Japanese Patent Laid-Open No. 2001-199049).

Japanese Patent Laid-Open No. 2001-199049 (Japanese Patent Application No. 2000-14712)

However, when water-based gravure printing is performed using the above-described FIG. 2 and the finisher rolls 5 and 5a of Patent Document 1, the water-based ink 2 is removed from the ink pan 1 in low-speed printing of several tens of meters / minute from the start of the printing operation. When supplied to the plate cylinder 3, it does not scatter due to the centrifugal force of the plate cylinder 3 and the gravity of the water-based ink, but it takes time to reach the doctor knife 4 after supplying the water-based ink 2. The water-based ink 2 tends to be rounded by the large surface tension on the surface of the plate cylinder 3. As a result, ink unevenness occurs due to the density of ink wetting, and “thread-like blur” occurs in the printed matter. As a solution, an appropriate amount of water-based ink is supplied on the surface of the doctor knife 4 side plate cylinder 3 until it reaches the doctor knife 4, and the water-based ink 2 is not rounded due to the surface tension, so that a uniform coating state is obtained. I understood that it would be good.
An object of the present invention is to provide a gravure printing machine using water-based ink that ensures a uniform coating state when water-based ink is used .

In order to solve the above-mentioned problem, in the gravure printing press using the water-based ink according to claim 1, in the gravure printing press in which the finisher roll is arranged on the opposite side of the doctor knife, between the ink pan and the doctor knife , An ink leveling roll that rotates in contact with the plate cylinder is arranged at a position that is not in contact with the ink in the ink pan, and the peripheral speed of the finisher roll is set to 5 to 50% of the peripheral speed of the plate cylinder. The peripheral speed of the ink leveling roll is set to 5 to 120% of the peripheral speed of the plate cylinder.

  According to the present invention, in the case of low-speed printing, the water-based ink does not scatter from the plate cylinder surface, but since the speed is low, it takes time to reach the doctor knife after supplying the water-based ink. The ink tends to curl due to its large surface tension on the surface of the plate cylinder, resulting in poor wetting, resulting in a “thread-like ink fading” that is different from that at high speeds. By providing an ink leveling roll and setting this peripheral speed to 50 to 120% of the peripheral speed of the plate cylinder, the amount of water-based ink that tends to be rounded by the surface tension on the plate cylinder surface is reduced, and the coating film It can be solved by reaching the doctor knife while making the surface uniform. This peripheral speed is set in consideration of the properties of ink to be used, temperature, paper quality, and the like.

  According to the first aspect of the present invention, it is possible to obtain a printed matter that does not cause “fogging of the thread-like ink” even during low-speed printing of about 70 meters / minute from the start of the work operation.

  As a result, when water-based ink is used, waste at the start of printing can be eliminated and productivity can be increased as compared with the conventional case.

It is explanatory drawing which shows the water-based ink use gravure printing machine which concerns on this invention described in Claim 1. It is explanatory drawing of the finisher roll apparatus in the gravure printing machine of patent document 1 which provided the finisher roll in the both sides of the plate cylinder. It is explanatory drawing of the conventional gravure printing machine.

The present invention is a gravure printing machine that uses water-based ink, and exhibits its effectiveness especially during low continuous printing .

As shown in FIG. 1, the finisher roll 5 is disposed on the opposite side of the doctor knife 4 between the ink pan 1, the plate cylinder 3, and the ink pan 1 filled with the water-based ink 2. Further, an ink leveling roll 5 a is provided on the doctor knife 4 side between the ink pan 1 and the doctor knife 4 and in a non-contact state with the ink 2. In the figure, 6 is an impression cylinder and 7 is a film.

  In the above configuration, the peripheral speed (surface rotational speed) of the finisher roll 5 is set in a range of 5 to 50% with respect to the peripheral speed (surface rotational speed) of the plate cylinder 3, and the peripheral speed of the ink leveling roll 5a. (Surface rotation speed) is set in a range of 5 to 120% with respect to the peripheral speed (surface rotation speed) of the plate cylinder 3.

  At the above peripheral speed, if the peripheral speed of the finisher roll 5 exceeds 50%, the ink wets excessively, the ink pool increases, and if it reaches 5% or less, insufficient wetting occurs.

  On the other hand, when the peripheral speed of the ink leveling roll 5a exceeds 120%, insufficient ink coating (wetting) occurs, and when it is 5% or less, a problem of excessive coating (wetting) occurs.

The first embodiment, which corresponds to the invention described in claim 1 will be described in detail with reference to FIG.

  In FIG. 1, reference numeral 1 denotes a dish-shaped ink pan. The ink pan 1 is filled with water-based ink 2. For this water-based ink 2, trade name “Aqua Ecole S” (surface tension 24 dyne / cm) manufactured by Toyo Ink Manufacturing Co., Ltd. is used.

  Reference numeral 3 denotes a plate cylinder. The surface of the plate cylinder 3 is processed with a plate depth of 13 μm and a line number of 350 by laser plate making. 4 is a doctor knife, 5 is a finisher roll disposed in the opposite direction to the doctor knife 4, and 5 a is the same example as the doctor knife 4, and is an ink leveling roll disposed between the ink pan 1 and the doctor knife 4. The peripheral speed of the finisher roll 5 is set to a peripheral speed of 150 m / min, which is 50% of the peripheral speed of the plate cylinder 3, and the peripheral speed of the ink leveling roll 5 a is the peripheral speed of the plate cylinder 3. The peripheral speed is set at 300 m / min, which is 100% of the speed of 300 m / min. 6 is an impression cylinder, and 7 is a biaxially stretched PP film (20 μm).

  As a result of printing at 300 m / min according to Example 1, an ink coating film was formed on the surface of the plate cylinder 3 by the finisher roll 5, and the ink was prevented from being rounded by the ink leveling roll 5a. By making the adjustment uniform, a good printed matter without “fogging of thread-like ink” immediately after the start of printing was obtained.

Comparative Example 1

  In FIG. 1, the peripheral speed of the finisher roll 5 is set to 55% with respect to the peripheral speed of the plate cylinder 3, and the peripheral speed of the ink leveling roll 5a is set to 125% with respect to the peripheral speed of the plate cylinder 3. When printing was carried out under the same conditions as in Example 1 except for the above, “thread-like ink fading” occurred as a whole.

Comparative Example 2

  Printing was performed under the same conditions as in Example 1 except that the peripheral speed of the finisher roll 5 and the ink leveling roll 5a was set to 4% with respect to the peripheral speed of the plate cylinder 3, and in particular, 80 m / m from the start of printing. A lot of “fogging of thread-like ink” was seen up to the minute.

  Printing was performed under the same conditions as in Example 1 except that oil-based gravure ink (trade name NEWLP Super, manufactured by Toyo Ink Manufacturing Co., Ltd., surface tension 17 dyne / cm) was used as the ink. As a result, a good printed matter was obtained even when the printing speed was increased to 350 m / min with respect to the usual 320 m / min.

Comparative Example 3

  When printing was performed under the same conditions as in Example 1 using the gravure printing machine in which the finisher roll 5 was disposed only on the opposite side of the doctor knife 4 shown in FIG. 3, the ink was used at a printing speed of 200 m / min or more. Drops, printing unevenness occurred, and good printed matter could not be obtained.

  As described above, the finisher roll 5 is disposed on the opposite side of the doctor knife 4, and the ink leveling roll 5 a is disposed between the ink pan 1 and the body plate 3 and in a non-contact state with the ink 2. The peripheral speed of the ink leveling roll 5 a is set to 5 to 120% of the peripheral speed of the plate cylinder 3, and the peripheral speed of the finisher roll 5 is set to 5 to 5 with respect to the peripheral speed of the plate cylinder 3. By setting it to 50%, even when using high-surface-tension water-based gravure ink, there is no ink rounding or wetting failure from low speed printing work at the start of printing work to several tens of meters / minute to high speed printing work. Good prints with no “fogging of thread-like ink” or “plate fog” were obtained. Therefore, according to the present invention, it is possible to cope with environmental problems due to the use of water-based ink, and it is possible to increase the printing speed.

1 Ink pan 2 Water-based ink 3 Plate cylinder 4 Doctor knife 5 First roll 5a Ink leveling roll 6 Impression cylinder 7 Film

Claims (1)

In a gravure printing machine in which a finisher roll is arranged on the opposite side of a doctor knife , an ink leveler that rotates between the ink pan and the doctor knife in contact with the plate cylinder at a position that does not contact the ink in the ink pan. The peripheral speed of the finisher roll is set to 5 to 50% of the peripheral speed of the plate cylinder, and the peripheral speed of the ink leveling roll is set to 5 to 120% of the peripheral speed of the plate cylinder. A gravure printing machine using water-based ink, characterized in that it is set.

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