JP2002001915A - Method and device for humidifying paper for printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve ink acceptability of paper by giving proper water to the printing surface of a paper in the printing line to obtain good print reproducibility at a low printing pressure. SOLUTION: A paper humidifying device A that gives proper water to the surface of the printing paper is installed in front of a printing unit, and is composed of a humidification cylinder 1 having an aggregate of minute recesses 1B to accumulate a small amount of water from a water pail 2 on its surface, a doctor knife 4 for scraping extra water on the humidification cylinder 1, and a support cylinder 3 for supporting the printing paper (not shown) paired with the humidification cylinder 1. By making the printing paper pass between the humidification cylinder 1 and the support cylinder 3, the surface of the printing paper is humidified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper humidifying apparatus for a printing press using a rolled paper, which can apply a suitable amount of moisture to the surface of a printing area of a printing paper by an unused cylinder in a printing line. The invention relates to a printing press having a device.

[0002]

2. Description of the Related Art Conventionally, in a printing press using a rolled paper, the smoothness of the printing surface of the paper used in the printing press may be poor, and the reproducibility of the printed pattern may be poor. This is because the acceptability of the paper is low. As a countermeasure, a method is adopted in which the printing pressure is increased to forcibly transfer the ink to the paper. However, when the printing pressure is increased, the load on the printing press and the load on the paper increase, resulting in deterioration due to the curvature of the plate cylinder shaft, damage to the paper, and deterioration in reproducibility that occurs when the printing pressure is too high. There was a problem. For this reason, in offset printing, as a method of improving ink receptivity, a method of humidifying the entire printing paper by providing a special humidifying means such as a spray in front of the printing unit has been adopted. In such a conventional humidification method, a separate humidification unit is provided, so that the apparatus becomes large-sized and the cost is increased, and a portion other than the printing area is humidified in order to humidify the entire printing paper.
There is a problem that wrinkles are generated on the paper, or in the case of a paper having glue applied on the back surface, the paper is curled or the glue is melted and adheres to another paper.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide good print reproduction without increasing printing pressure (printing pressure). In order to obtain the property, without using special humidifying means, use the part of the unused device in the printing line to give a suitable amount of moisture to the surface of the paper printing area, Is to improve the ink receptivity of the paper without adverse effects.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a printing press using web paper, wherein moisture is retained only in a printing area on a surface of an unused printing cylinder in a printing line, and the printing paper surface immediately before printing is provided. Paper humidifying method for a printing press in which the print area of the above is appropriately humidified to improve the ink receptivity at the time of subsequent printing.

The present invention relates to a gravure rotary printing press,
Water holding means for holding water on the surface of the printing area after the printing plate not used for printing, water supply means for supplying water to the surface of the printing plate, and water holding water on the surface of the printing plate And a paper humidifier for a printing press, which is provided with a water removing means for removing excess water, and applies an appropriate amount of moisture to the surface of the printing paper immediately before printing.

According to the present invention, there is provided a paper humidifying device for a printing press, wherein the water holding means comprises an aggregate of fine depressions, and the water scraping means comprises a doctor blade.

The present invention is a paper humidifier for a printing press for adjusting the amount of water applied to a paper by changing the depth and area of the fine depression.

The present invention is a paper humidifying device for a printing press for matching the shape of the aggregate of fine depressions with the shape of a printing portion.

The present invention is a paper humidifier for a printing press, wherein the water supplied from the water supply means contains a certain amount of alcohols.

[0010] The present invention relates to a printing press using a wrapping paper, wherein a cylinder having a humidifying function having water retaining means for retaining water on the surface thereof in a printing line; A cylinder for supporting water, a water trough located on the lower surface of the cylinder with humidifying function and supplying water to the surface thereof, and a water scraper for scraping excess water out of water held on the surface of the cylinder with humidifying function. And a sheet humidifying device for a printing press, which is provided with a removing means and imparts an appropriate amount of moisture to the surface of the printing paper immediately before printing.

[0011]

Embodiments of the present invention will be described below. The present invention is a paper humidifier for a printing press capable of applying an appropriate amount of moisture to the surface of a printing paper in order to improve the ink receptivity of the printing press. A humidifying cylinder having moisture holding means for holding, a support cylinder for supporting the printing paper in contact with the humidifying cylinder, a moisture supply means for supplying water to the surface of the humidifying cylinder, and a water holding means held on the surface of the humidifying cylinder. A means for removing excess water from the water is provided, and the printing paper passes between the humidifying cylinder and the support cylinder to humidify the printing surface of the printing paper. The water supply means includes a water tub for storing water, and the water retention means includes an aggregate of fine depressions provided on the surface of a humidifying cylinder or a water absorption layer made of a water absorbing material. Examples thereof include a doctor knife and a pressing roller. In the case of a gravure rotary printing press, if there is a unit (cylinder) not used for printing, an aggregate of minute depressions should be provided on the surface of the unit (cylinder) not used for printing so that a small amount of water can be accumulated. Thereby, humidification can be performed without specially installing a new humidification device. Further, the amount of moisture to be humidified can be changed by changing the depth and area of the fine dent or adjusting the pressing force of the pressing roller for pressing the water absorbing layer. Further, by matching the shape of the aggregate of the fine depressions or the pattern of the water-absorbing layer with the shape of the printed portion, it is possible to apply moisture only to the printed portion, and it is possible to suppress the application of excess moisture.

[0012]

FIG. 1 is a diagram showing a paper humidifier A of a printing press according to the present invention. The paper humidifier A includes a humidifying cylinder 1 for supplying moisture, a water tub 2 for storing water, and a humidifying cylinder 1.
And a doctor cylinder 4 for removing excess water on the humidifying cylinder 1. Shaft holes 1A and 3A through which the shaft passes are made at the center of each cylinder. The humidifying cylinder 1 has a fine recess 1B so as to easily hold moisture on its surface.
Is provided. The depth and area of the fine depression 1B are adjusted according to the degree of humidification.
Further, by adjusting the shape of the aggregate 1C of the fine depressions 1B to the shape of the plate surface of the printing portion, it is possible to apply moisture only to the printing portion, and it is possible to suppress the application of excess moisture.

FIG. 2 shows a paper humidifying apparatus A for a printing press according to the present invention.
FIG. 3 is a view showing a state in which is installed in a printing press. Frame 5
In the figure, a water tub fixing frame 6 for fixing the water tub 2 and a cylinder fixing frame 7 are integrated. The cylinder fixing frame 7 has a shaft fixing hole for fixing a shaft passing through the humidifying cylinder 1 and the support cylinder 3. 7A and 7B
Is provided.

The support cylinder 3 and the humidifying cylinder 1 are fixed to a cylinder fixing frame 7. By making the shaft fixing hole 7A for fixing the shaft on the side of the support cylinder 3 vertically long, the vertical direction of the support cylinder 3 becomes free,
It is possible to cope with various types of paper 8 having different thicknesses. The frame 5 is fixed to the printing press frame 9.

The water 10 is put into the water tub 2 so that the lower part of the humidifying cylinder 1 is immersed in the water 10. Alcohol or the like may be mixed in the water 10. The paper 8 passes between the humidifying cylinder 1 and the supporting cylinder 3, and the friction causes the cylinders to rotate. A power source (not shown) may be separately provided for the rotation of the humidifying cylinder 1. By the rotation of the humidifying cylinder 1, the water 10 in the water trough 2 is aggregated 1C of fine depressions 1B.
And the excess water is scraped off by the doctor knife 4, so that a suitable amount of moisture is given to the printing surface of the paper 10.

A humidifier for a gravure rotary press will be described below as a second embodiment. FIG. 3 is a diagram showing a humidifying plate B which is a humidifying device of the gravure rotary press. In a gravure rotary press, when there is a unit that is not used for printing, by using the plate surface of this unit as the humidifying plate surface B, humidification can be performed without installing a new device. The humidifying plate surface B is provided with an aggregate 1C of fine depressions 1B so that the surface can sufficiently retain moisture. The depth and area of the fine depression 1B are adjusted according to the degree of humidification. Furthermore, by matching the shape of the aggregate 1C of the fine depressions 1B with the shape of the printed portion, it is possible to apply moisture only to the printed portion, so that the application of excess moisture can be suppressed.

The fine depression 1B provided on the surface of the humidifying cylinder 1 shown in FIG. 1 is for printing a single large pattern, and the fine depression 1B provided on the surface of the humidifying plate surface B shown in FIG. 1B is for printing a plurality of small identical symbols.

FIG. 4 is a view showing an installation example in which the humidifying plate B is installed on a gravure rotary press. Plate B for humidification
Is attached to a unit not used for printing in front of the unit used for printing in the same manner as a normal printing plate.

At the lower part of the humidifying plate B, an ink pan 11 for mounting a printing ink for normal printing is attached. The water 10 is put in the ink pan 11 instead of the ink so that the water 10 is immersed in the inking roller 12. Alcohol or the like may be mixed in the water 10. The water 10 attached to the inking roller 12 is supplied to the humidifying plate surface B,
The water 10 adhering to the aggregate 1C of the fine depressions 1B of the humidifying plate B is rotated by a doctor knife 4 in a state where excess water is scraped off and an appropriate amount of water is stored. Since the paper 8 passes between the impression cylinder 13 and the humidifying plate B as in the case of normal printing, the water 10 stored in the aggregate 1C of the fine depressions 1B on the surface of the humidifying plate B is It transfers to the surface of the printing surface of the sheet 8 in contact with the humidifying plate surface B and is appropriately humidified. In place of the assembly 1C of the depressions 1B and the doctor knife 4 provided on the humidifying plate B, the water absorbing layer 1 made of a water absorbing material on the surface shown in the other embodiment is used.
The humidifying cylinder 1 and the pressing roller 4a provided with c can also be used.

[0020]

According to the humidifying device of the present invention, good print reproducibility can be obtained without increasing the printing pressure even when using paper having a poor surface smoothness. In a special color printing press of a gravure rotary press, 5
It is possible to print six colors, and if even one color is not used, it is necessary to add a new humidifier by using a unit not used for this printing as a humidifier. There is no cost. Further, since the moisture to be humidified can be adjusted, it is possible to cope with various types of paper having different materials or thicknesses. Furthermore, since only the printing portion can be humidified, the adhesion of excess moisture to the non-printing portion is suppressed, and only the printing portion receives ink, and the non-printing portion does not receive ink. Quality (printing accuracy) is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a paper humidifying device of a printing press according to the present invention.

FIG. 2 is a diagram showing a state in which the paper humidifying device of the printing press of the present invention is installed in the printing press.

FIG. 3 is a diagram showing a humidifying device of a gravure rotary press using a humidifying plate, which is another embodiment of the paper humidifying device of the present invention.

FIG. 4 is a view showing a state in which a humidifying plate surface according to another embodiment of the paper humidifying apparatus of the present invention is installed in a gravure rotary press.

[Explanation of symbols]

 Reference Signs List A Humidifier B Humidifying plate surface 1 Humidifying cylinder 1A Shaft hole 1B Fine depression 1C Aggregate of fine depressions 2 Water trough 3 Support cylinder 3A Shaft hole 4 Doctor knife 5 Frame 6 Water trough fixing frame 7 Cylinder fixing frame 7A Shaft fixing Hole 8 Paper 9 Printing machine frame 10 Water 11 Ink pan 12 Receiving roller 13 Impression cylinder

Claims (7)

[Claims] 1. A printing press using a web,
Moisture is retained only in the printing area on the unused printing cylinder surface in the printing line, and the printing area on the printing paper surface immediately before printing is moderately humidified to improve ink receptivity during subsequent printing. A paper humidifying method for a printing press, comprising: 2. A gravure rotary printing press, wherein a water holding means for holding water on a surface of an area where printing is performed after a printing plate not used for printing, a water supply means for supplying water to a surface of the printing plate, A paper humidifier for a printing press, characterized in that a water removing means for removing excess water from water holding water is provided on the surface of a printing plate to provide a suitable amount of water to a printing paper surface immediately before printing. apparatus. 3. The paper humidifying device for a printing press according to claim 2, wherein said water holding means comprises an aggregate of fine depressions, and said water scraping means comprises a doctor blade. 4. The paper humidifying device for a printing press according to claim 3, wherein the amount of moisture given to the paper is adjusted by changing the depth and area of the fine depression. 5. The paper humidifying apparatus for a printing press according to claim 3, wherein the shape of the aggregate of the fine depressions is matched with the shape of a printing portion. 6. The water supplied from the water supply means contains a certain amount of alcohols.
A paper humidifier for a printing press according to Claim 1. 7. A printing press using web paper,
During the printing line, a cylinder with a humidifying function having a water retaining means for retaining water on the surface thereof, a supporting cylinder for supporting the paper in contact with the cylinder with the humidifying function, and a cylinder located at the lower surface of the cylinder with the humidifying function. A water trough for supplying water to the surface thereof, and a water removing means for removing excess water from the water held on the surface of the cylinder with the humidifying function, so that an appropriate amount of moisture is applied to the surface of the printing paper immediately before printing. A paper humidifying device for a printing press, which is provided.