JPH0228469B2 - MAIYOINSATSUKINOSHIGAISENKANSOREIKYAKUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultraviolet ray drying and cooling device for a sheet-fed printing press that dries a printed material by irradiating it with ultraviolet rays and then cools it.

Ultraviolet curing ink is known as a type of printing ink used in lithographic printing and the like. In the printing process using this type of printing ink,
An ultraviolet drying method is used in which the printing material immediately after printing is irradiated with light from a mercury lamp to absorb ultraviolet energy, thereby hardening and adhering the ink to the printing material. Conventionally, mercury lamps with a power per unit length of about 80 to 160 W/cm have been used for ultraviolet drying, but in this type of mercury lamp, the ultraviolet rays that are effective for ink drying out of the entire lamp's energy are used. Since only about 10 to 15% of energy is converted into energy, for example, if you are printing on a substrate with poor ink adhesion, such as plastic film or sheet or synthetic paper, you should increase the power of the mercury lamp, or increase the power of the mercury lamp. Unless the traveling speed is slowed down, it will not dry properly, and if the drying is insufficient, it will often get rubbed and get dirty, or it will get dirty when it gets turned over when loaded. However, the light beam from a mercury lamp is
With the exception of ~15% ultraviolet rays, all visible and infrared rays emit heat rays, so the center of the lamp reaches a high temperature of 800 degrees Celsius while the lamp is on. Therefore, when increasing the electric power per unit length of the lamp to improve ink adhesion for heat-sensitive plastic films, etc., quality problems such as expansion/contraction, deformation, deterioration, or misregistration may occur due to the effects of heat. It was hot. On the other hand, slowing down the running speed of the printing material reduces efficiency in relation to printing speed, and also reduces the power per unit length of the lamp to increase the number of lamps and lengthen the irradiation time. As a result, the equipment became larger, which caused problems in terms of increased floor space and equipment costs, as well as maintenance.

Therefore, as a countermeasure to this problem, a method called water-cooled lamp drying was proposed. This method involves layering a special glass filter with high UV transmittance under a mercury lamp, passing water through it, and drying while cooling with this water.This method uses pure water for cooling. Not only does this require large equipment and troublesome maintenance, but energy is lost when the ultraviolet rays pass through special glass, reducing drying efficiency.
The drawback was that it dropped by about 30%.

Another method proposed was to connect a conveyor-type ultraviolet drying device to the printing press and provide a cooling zone after the ultraviolet irradiation to prevent the temperature of the printing material from rising. The printing material that has been conveyed while being held by the provided claws may bend when it falls onto the conveyor belt, and there is nothing to restrain it when it is conveyed on the belt, making it impossible to increase the speed. There are many disadvantages, such as heat and the inability to properly align the paper at the stacker.Furthermore, connecting a conveyor type drying device to the printing machine lengthens the entire machine and requires a large floor space. It has not been put into practical use yet.

The present invention has been made in view of the above points, and includes a structure in which the printed material is dried with ultraviolet rays after printing, and an air cooling device and a cooler are installed in parallel to cool the printed material. This makes it possible to completely remove ink from printing materials that are sensitive to heat and have poor ink adhesion, such as plastic film, without reducing printing speed or causing quality problems such as expansion/contraction deformation. The present invention provides an ultraviolet ray drying/cooling device for a sheet-fed printing press that can harden and adhere.

Hereinafter, its configuration and the like will be explained in detail with reference to embodiments shown in the drawings.

The figure shows a side view of a sheet-fed printing press incorporating an ultraviolet drying device according to the present invention. In this embodiment, a plastic film is used as the printing material, and an ultraviolet curing ink is used as the printing ink. In the figure, there is a paper stacking stand 1 at the rear end of the machine.
A paper feeding device 4 is provided, which includes a picker 3 and the like, which sucks the printing materials 2 stacked on the paper stacking table 1 one by one from the upper layer. And this paper feeding device 4
4 through the insert plate 5 and belt 6.
A set of printing units 7 and three paper transfer cylinders 8 are arranged. This printing unit 7 includes a plate cylinder 9 each equipped with a printing plate, a group of ink rollers 10 that supplies ink to the printing plate, a group of water supply rollers 11 that also supplies water, and a system that displaces ink and water. Rubber cylinder 12 to which the image formed on the printing plate is transferred
and an impression cylinder 1 which is located between the blanket cylinder 12 and the paper transfer cylinder 8 and presses the printing material 2 passing between the blanket cylinder 12 and the blanket cylinder 12 to print an image thereon.
It is composed of 3 etc. In the figure, the ink roller group 10 and the water supply roller group 11 are omitted except for the printing unit 7 at the forefront. The printing material 2 then enters the printing unit 7 from the paper feeder 4 via the belt 6, is transferred to the first impression cylinder 13 by the swing claw device 14, and is then transferred to the impression cylinder 13 of each printing unit 7 and The paper is printed one after another while passing through the transfer cylinder 8, and reaches the impression cylinder 13 of the final printing unit 7.

On the other hand, a paper discharge section 16 is provided at the frontmost end of the machine, and includes a paper stacking table 15 on which printed materials 2 that have been printed are stacked. A pair of left and right sprockets are disposed between the sprocket 17 provided at the upper part of the paper discharge section 16 and the sprocket 19 provided coaxially with the gripping cylinder 18 facing the impression cylinder 13 of the final stage printing unit 7. An endless chain 20 is stretched. On this endless chain 20, a plurality of claws 21 for holding the printed material 2 after printing are arranged at regular intervals, and the held printing material 2 is moved in the direction shown by the arrow in the figure. The paper is conveyed to the paper discharge section 16 by the endless chain 20 that runs on the paper.

At the starting end of the conveyance path of the endless chain 20 and between its upper running part and lower running part, an ultraviolet irradiation device 23 equipped with a plurality of mercury lamps 22 is provided.
is provided, and the irradiation direction of the mercury lamp 22 is directed downward, and the irradiation direction is irradiated onto the upper printing surface of the printing material 2 traveling together with the endless chain 20. Between the ultraviolet irradiation device 23 and the paper discharge section 16, a pair of air cooling devices 24 and 25 are provided near the ultraviolet irradiation device 23 and above the paper discharge section 16, respectively. Among these, the air cooling device 24 is provided with a large number of injection ports that open vertically and forwardly, and cool air sent from a blower device (not shown) is directed downward to the printing material 2 and its surroundings. and upwardly and forwardly toward the endless chain 20 and its surroundings. Further, the air cooling device 25 is provided with a large number of blowing ports that open downward, and the cold air sent from the blowing device is sprayed toward the printing materials 2 stacked on the paper stacking table 15. do.

Furthermore, a claw 21 is attached below the printing material 2 conveyed by the endless chain 20 so that the portion of the printing material 2 other than the edge gripped by the claw 21 slides into contact with the material under its own weight.
A cooler consisting of a cooling pipe 26 extending along a position slightly lower than that is provided approximately corresponding to the ultraviolet irradiation device 23, through which cold water sent from a water supply device (not shown) passes. It is configured to cool the printing medium 2 that is traveling while slidingly in contact with the cooling pipe 26 .

That is, since the pawl 21 is the mechanical component that comes closest to the cooling pipe 26 during conveyance of the printing material 2, if the pawl 21 and the cooling pipe 26 are set to be as close as possible, the pawl The distance between the printing material 2 held in the jaw 21 and the cooling pipe 26 can be approximately 8 to 10 mm, and the printing material 2 is held in the claw 21.
Because the edges other than the gripped edge are not held by the gripper, it tilts downward toward the bottom side due to its own weight. The cooling pipe 26 is in sliding contact with the exception of a part of the cooling pipe 26 . In addition,
During high-speed rotation, the printing medium 2 is conveyed while fluttering, so it may be conveyed while coming into contact with or away from the cooling pipe 26, but even in this case, air cooling devices 24 and 25 are provided afterwards. Because of this, sufficient cooling is possible.

In the ultraviolet drying and cooling apparatus configured as described above, the printed material 2 is transferred from the impression cylinder 13 of the final stage printing unit 7 to the endless chain 20 via the paper gripping cylinder 18. It is also conveyed along the cooling pipe 26. During this time, the light from the mercury lamp 22 of the ultraviolet irradiation device 23 is first irradiated, and about 10 to 15% of the ultraviolet rays of this irradiation light are absorbed by the printing material 2, and the ultraviolet curing ink dries and the printing material It is hardened and adhered to 2. The printing material 2 is cooled by a cooling pipe 26 during irradiation with ultraviolet rays, and is cooled by an air cooling device 24 after irradiating ultraviolet rays.
The paper is further cooled by an air cooling device 25 after the paper is ejected. Therefore, the printing material 2 made of heat-sensitive plastic film does not undergo expansion, contraction, deformation, etc., and the printing ink is completely hardened and adhered to the printing material 2. Further, since the ultraviolet rays are directly irradiated onto the printing material 2, there is no loss of ultraviolet energy and the irradiation efficiency is high. Furthermore, the cold air jetted by the air cooling device 24 is not limited to the printing medium 2;
Since the heating is applied to the periphery, upward and forward, it is possible to prevent an increase in the environmental temperature around the ultraviolet drying device as well as an increase in the temperature of the claws 21 of the endless chain 20 and the like. In particular, hard rubber or urethane rubber is used for the claws of the endless chain 20 to impart wear resistance, and by preventing the temperature of the claws from rising, deterioration due to heat can be prevented.

In this example, a plastic film was used as the printing material, but a plastic sheet or synthetic paper would have the same effect, and the printing material was dried and cooled while being held between the claws of an endless chain. Therefore, it is extremely suitable not only for printing materials that are sensitive to heat, but also for thin paper, base paper, etc. Furthermore, although cold water is used for cooling by the cooling pipe in this embodiment, cold air may be used instead.

As is clear from the above description, according to the present invention, in a sheet-fed printing press, an ultraviolet irradiation device and an air cooling device are installed in the conveyance path of the endless chain that conveys the printing material from the printing unit at the final stage to the paper discharge section. In addition, by arranging a cooler below the endless chain to dry the printing ink on the printing material by irradiating ultraviolet rays, and cooling the printing material at the same time as drying or after drying. Even in printing operations using printing materials such as heat-sensitive plastic films, the quality is improved without causing expansion, contraction, deformation, deterioration, or misregistration of the printing material, and the printing ink is used efficiently and completely. Since it is hardened and adhered to the printing material, the quality is significantly improved without staining due to rubbing or staining due to backing up during loading. Furthermore, since there is no deformation and expansion of the printing material due to heat, the registration accuracy during double printing is good, and the number of printing colors can be increased, which is highly effective. Furthermore, since there is no need to slow down the running speed of the printing material to account for insufficient drying of the printing ink, it is possible to increase the printing speed, and since all the equipment is built into the printing machine, it is compact and Does not require floor space.

[Brief explanation of drawings]

The figure is a side view of a sheet-fed printing press that implements the ultraviolet drying and cooling device according to the present invention. 2...Printing material, 7...Printing unit, 16...
... Paper discharge section, 20 ... Endless chain, 23 ... Ultraviolet irradiation device, 24, 25 ... Air cooling device, 26 ...
cooling pipe.

Claims (1)

[Claims] 1 In a sheet-fed printing press that is provided with an ultraviolet irradiation device 23 that irradiates the upper printing surface of the printing material 2 with ultraviolet rays between the final stage printing unit 7 and the paper discharge section 16, the ultraviolet ray irradiation device 23 and the paper discharge section An air cooling device 24 having a large number of jetting ports that jets cool air toward the printing medium 2 and its surroundings, which are transported between the cooling unit 16 and the printing medium 2
A sheet-fed printing machine characterized in that a cooling pipe 26 is provided below the ultraviolet irradiation device 23 and extends along the conveying direction, through which the lower surface of the printing material 2 is rubbed under its own weight. Ultraviolet drying cooling device.