JPS63116851A - Flexographic press - Google Patents

Abstract

PURPOSE:To stabilize the quality of printed matter and to enhance yield, by arranging a printing part in a casing hermetically closed excepting the inlet and outlet of the feed system of a material to be printed and further arranging a solvent sump of printing ink equipped with an ultrasonic vibrator in the casing. CONSTITUTION:A printing part is arranged in a casing 9 hermetically closed excepting the inlet and outlet of the feed system of a material to be printed and a solvent sump 10 equipped with an ultrasonic vibrator 11 is further arranged in the casing 9. A solvent to which ultrasonic vibration is applied evaporates to fill the casing with solvent gas in an equilibrium state with respect to the saturation vapor pressure of the temp. in the casing 9. Since the printing part is arranged under this state, the diffusion of the solvent of the printing ink on a printing plate 2, an anilox roll 4 and a doctor roll 5 is not generated at all and the optimum printing condition is always kept. Therefore, the quality of printed matter is stabilized and yield is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a flexo printing machine, which has been increasingly used in recent years as a method that is excellent in terms of economy, versatility, and high speed.

2. Description of the Related Art As shown in FIG. 2, the printing part of a conventional flexible printing press includes a plate cylinder 3 to which a printing plate 2 is attached. Anilox roll 4.
)" It consists of a lid roll 5, a conveyance system 7 for the workpiece 1, etc. Printing ink is transferred from a syringe 6 to an anilox roll 4 and a doctor roll 5 rotating in the opposite direction to adjust the film thickness to a constant level. .Anilox roll 4
The printing ink that has become almost uniform in film thickness is transferred from the anilox roll to the printing plate 2 attached to the printing cylinder 3, and then moved from the printing plate 2 in the direction of the arrow 8 by a conveyance system 7. The image is transferred to the next workpiece 1.

Problems to be Solved by the Invention In a flexo printing machine having the above configuration, printing ink with high drying properties is sometimes used for the purpose of printing versatility, high speed, etc. Generally, printing inks with high drying properties are of a type in which the solvent used to dilute pigments and the like easily evaporates. When printing with such printing inks, if the viscosity of the ink changes due to evaporation of the solvent during the printing process, the printing conditions will change and the quality of the printed matter will become unstable.

Furthermore, when the solvent in the printing ink evaporates during the printing process, the pigment concentration in the ink increases relatively, causing an increase in the film thickness of the printed matter, color tone, etc., and deteriorating the quality of the printed matter.

Therefore, the flexographic printing machine of the present invention is capable of continuous printing with stable quality even when printing ink with high drying properties is used, and is capable of realizing an improvement in the yield of mass production of printed matter.

Means for Solving the Problems The flexographic printing machine of the present invention has a plate cylinder equipped with a printing plate that transfers printing ink to the printing material, an anilox roll that transfers the printing ink to the printing plate, and a constant film thickness on the anilox. The printing part, which is equipped with a doctor roll that distributes the printing ink, is installed inside a sealed casing except for the entrance and exit of the conveyance system for the printed material, and a printing ink solvent reservoir equipped with an ultrasonic vibrator is installed inside this casing. This is what I did.

Effect According to the above configuration, the printing ink is applied to the 7J11
The printing plate, anilox roll, and doctor roll are installed in a sealed casing, which minimizes the diffusion of printing ink solvent into the surrounding air. Since the solvent gas from the solvent reservoir increases the solvent gas concentration in the casing 9, the diffusion of solvent from the printing ink is small. Therefore, changes in the viscosity of the printing ink and changes in the solvent content during the printing process are suppressed, and the quality of printed matter is stabilized.

Effective in improving yield.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a printing section of a flexo printing machine according to an embodiment of the present invention. Note that the same components as those in FIG. 2 showing the conventional example are given the same numbers. Plate cylinder 3 with printing plate 2 attached. Anilox roll 4. The printing part equipped with the doctor roll 6 is installed in a sealed casing 9 except for the entrance and exit of the conveyance system 7 for the substrate 1, and a solvent reservoir 1o equipped with an ultrasonic vibrator 11 is still inside the casing 9. It is installed.

The effects of this embodiment are as follows. In the printing part of a conventional flexible printing machine, as shown in Figure 2, an anilox roll is coated with printing ink.

The printing plate and doctor roll were exposed to the outside air, and the solvent in the printing ink diffused into the outside air, making it difficult to manage the printing ink. That is, during the printing process, changes in the viscosity of printing ink, changes in pigment concentration, etc. occur, causing instability in the quality of printed matter. In order to reduce the instability caused by this solvent diffusion, attempts have been made to increase the amount of ink supplied from the syringe to the anilox roll to reduce the amount of change such as the above-mentioned viscosity change, but some printing on the anilox roll Only the ink is transferred to the printing, and the solvent diffusion in the remaining printing ink cannot be prevented, resulting in concentration of the printing ink. Even if printing ink is supplied from above, printing ink that is thicker than the correct value will be present on the anilox, and printing instability will not be solved. Furthermore, there was no means to prevent the printing ink from dispersing the solvent on the printing plate.

In the flexo printing machine according to the embodiment of the present invention, as shown in FIG. Solvent reservoir 1o equipped with sonic vibrator 11
It is installed. The solvent subjected to ultrasonic vibration is vaporized, and the casing is filled with solvent gas in equilibrium with the saturated vapor pressure of the casing internal temperature. Since the printing part is installed under such conditions, the printing plate 2. Anilox roll 4. No diffusion of the printing ink solvent on the doctor roll 6 occurs, and optimal printing conditions are always maintained. Therefore, the quality of printed matter is stabilized and the yield is improved.

Effects of the Invention The flexographic printing machine of the present invention prevents changes in ink viscosity and solvent concentration in the printed area by preventing solvent diffusion of printing ink, and is capable of continuous printing while maintaining optimal printing conditions. . Therefore, it is effective in stabilizing the quality of printed matter, improving yield, and realizing maintenance-free operation.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a printing part of a flexographic printing machine according to an embodiment of the present invention, and FIG. 2 is a diagram showing a printing part of a conventional flexible printing machine. 9...Casing, 1o...Solvent reservoir, 11...Ultrasonic vibrator.

Claims (1)

[Claims] a printing section equipped with a plate cylinder equipped with a printing plate that transfers printing ink to a printing material; an anilox roll that transfers the printing ink to the printing plate; and a doctor roll that distributes the printing ink to a constant film thickness on the anilox roll. is installed in a casing that is sealed except for the conveyance system entrance and exit of the printing target section, and a solvent reservoir for the printing ink that is equipped with an ultrasonic vibrator is installed in the casing.