JPH04144749A - Sheet-fed press - Google Patents

Abstract

PURPOSE:To enable stable conveyance of a substance to be printed at a high speed even during irradiation with electron beams by a method wherein a cylinder for irradiation with electron beams having a rotary shaft paralleling a cylinder for printing is arranged at a stage preceded by a sheet-fed printing means. CONSTITUTION:When a high voltage is applied between an electron beam source and an electron beams acceleration pipe 20, electron generated by an electron beam source is accelerated downward. The accelerated curtainform electron beams injected through a metallic foil located in an irradiation window 22 and a substance to be printed on a cylinder 14 is irradiated therewith. The substance to be printed irradiated with the electron beams is conveyed to the outside by means of a gripper bar 45 situated to the chain of a delivery part 38. In a final unit 16, by making one full turn of a cylinder 36 for applying EB ink, printing is effected on the substance to be printed. Thus, it is imperative that the diameters of cylinders 18 and 30 for conveyance and the cylinder 14 for irradiation with electron beams are increased an integral number of times larger than the diameter of the cylinder 36 so as to match the timing of conveyance set by the cylinder 36.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides an electron beam irradiation means for curing electron beam curable ink (EB ink) by irradiating an electron beam onto the surface of a printing substrate immediately after printing. This invention relates to a sheet-fed printing machine installed after the printing means.

[Conventional technology]

FIG. 3 is a schematic cross-sectional view of a system that combines an ultraviolet irradiation device and a printing machine for sheet-like paper used in paper beverage containers, which has been widely used in the past. The front stage 40 of the printing press is part of a sheet-fed printing press consisting of a plurality of printing units that perform color printing on a sheet-shaped substrate,
The sheet-shaped printing material is conveyed between these printing units by being gripped by a number of cylinders whose rotating shafts are parallel, and being delivered and delivered at the portion where the cylinders contact each other. Then, the substrate to be printed is cured by irradiating it with ultraviolet rays using an ultraviolet ray irradiation device 42 installed downstream of the printing machine.

After the printing material has been processed in the final unit of the front stage 40 of the printing press, it is transported below the ultraviolet irradiation device 42 as the transport device 44 moves. Here, ultraviolet irradiation device 4
Step 2 is to irradiate the entire printing surface of the printing material with ultraviolet rays. The ink after printing is rapidly cured by photopolymerization reaction due to the ultraviolet rays.

FIG. 4 is a schematic cross-sectional view of a sheet-fed printing press similar to the above-mentioned printing press to which an electron beam irradiation device is connected. The curing treatment of EB ink by irradiation with electron beams has a higher throughput than the case of irradiation with ultraviolet rays, so that high-speed processing is possible.

Furthermore, when irradiating with electron beams, it is inevitable that X-rays that are harmful to the human body will be generated, so sufficient shielding with metal such as lead is required to prevent leakage of X-rays to the outside. It has been subjected.

A sheet-shaped substrate printed by the printing machine 41 is transferred to a conveyance path 48 of an electron beam irradiation device 46 . The outside of this transport path 48 is sufficiently shielded with lead to prevent leakage of X-rays generated by electron beam irradiation. The printing material transferred to the conveyance path 48 is transferred to the conveyor belt) 50
As the electron beam irradiation device 46 moves, it is transported directly below the electron beam irradiation device 46. The electron beam irradiation device 46 accelerates the electron beam generated by the electron beam source 52 by applying a high voltage between an electron beam source 52 and an electron beam acceleration tube 54 extending in a direction perpendicular to the figure. . As a result, a curtain-shaped electron beam is irradiated onto the printing material on the conveyor belt 50 through the irradiation window 56, and the EB ink on the printing material is cured.

[Problem to be solved by the invention]

If the ink is cured after printing by irradiation with ultraviolet rays as shown in FIG. 3, high-speed processing cannot be achieved unless multiple ultraviolet sources are used. Therefore, it is conceivable to provide an electron beam irradiation device instead of the ultraviolet irradiation device shown in FIG. 3, but this poses the following problems. That is, it is not only difficult to install the electron beam irradiation device in a horizontal position of the transport device from the viewpoint of leakage of XvA, but also difficult to create an inert atmosphere in the irradiation space.

In this way, the curing process for EB ink using an electron beam irradiation device can be performed more quickly than when using an ultraviolet irradiation device, and if only the curing process is considered, a processing speed comparable to that of the printing process can be achieved. be able to. However, in a conventional sheet-fed printing press using an electron beam irradiation device, as shown in Fig. 4, the material to be printed is conveyed by a conveyor belt in the electron beam irradiation device, so it is difficult to convey the material to be printed at high speed. I can't. That is, when this belt is moved at high speed in accordance with the processing speed of a printing press, a printing material simply placed on this belt may be displaced, curled up, or thrown up due to wind pressure.

For this reason, the moving speed of the conveyor belt is limited to the speed at which the printing material is stably conveyed, and the processing by the electron beam irradiation device cannot be increased to correspond to the processing speed of the printing press.

Furthermore, the weight of the sheet-like substrate is also limited. Specifically, while the current printing speed is about 200 m/min, the conveyance speed by a conveyor is limited to about 100 m/min.

The present invention has been made based on the above circumstances, and it is possible to transport the printing material at high speed and stably even when irradiated with an electron beam, and it is also possible to easily shield XwA. The purpose is to provide a sheet-fed printing press that takes up little space.

[Means to solve the problem]

To achieve the above-mentioned object, the present invention is a sheet of paper in which a sheet-like printing material is conveyed by a conveying cylinder, and a plurality of processes are sequentially passed through the printing material, and predetermined printing is performed by a printing cylinder. An electron beam irradiation means is provided with an electron beam irradiation cylinder having a rotation axis parallel to the cylinder at a subsequent stage of the leaf printing means, and irradiates the printing material with an electron beam while conveying the printing material by rotating the electron beam irradiation cylinder. and the diameter of the electron beam irradiation cylinder is an integral multiple of the diameter of the printing cylinder, and
It is characterized by having a value between 00 mm and 2000 mm.

[Effect]

According to the present invention, by providing the electron beam irradiation device downstream of the printing means, the curing ability of the EB ink is improved compared to the case where an ultraviolet ray irradiation device is used. Moreover, instead of conveying the material through the electron beam irradiation means using a conveyor belt, the material to be printed is conveyed while being gripped by an electron beam irradiation cylinder having a rotating shaft parallel to a plurality of cylinders used in the printing process. Therefore, the curing process by electron beam irradiation can be made as fast as the processing speed in the printing process.

In addition, by making the diameter of the electron beam irradiation cylinder an integral multiple of the diameter of the printing cylinder (generally referred to as a blanket cylinder), even when irradiating the printing material with the electron beam, it can be used in the printing process. It is possible to convey the substrate to be printed at the same timing as the conveyance.

Furthermore, the lower limit of the diameter of the cylinder for electron beam irradiation is set to 400 mm.
This prevents the leakage of X-rays to the outside due to the diameter of the electron beam irradiation cylinder being too small, and also reduces the bounce of the printing material, which is the raw material for paper beverage containers, etc., and improves the surface of the printed part. Prevents it from coming into contact with other objects and causing damage. On the other hand, by setting the maximum diameter of this cylinder to 2000 mm, the amount of metal such as lead used for shielding can be reduced while maintaining sufficient shielding against XwA generated by electron beam irradiation.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of the main parts of a sheet-fed printing press according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view showing an enlarged portion of an electron beam irradiation device.

In FIG. 1, below the electron beam irradiation device 10, there is arranged a cylinder 14 attached to the printing press for conveying the printing material, and this cylinder 14 has a maximum width of the printing material and a depth such as a path gap. Here, the printing material is, for example, a sheet-like material that becomes a container for a beverage product, and has a certain degree of hardness.

The electron beam irradiation device 10 is the final unit of the printing press in the previous stage) 16
It is installed at the rear of the . This final unit 16 is a unit for applying EB transparent ink to the surface of the printing material that has been colored with ink in the previous printing process. In all the printing processes including the final unit 16, the printing material is gripped and conveyed by the cylinder 18 and a number of cylinders having rotating shafts parallel to this, and the printing material is delivered at the part where these cylinders touch each other. will be held. This method of transporting printing materials using multiple cylinders is a well-known technique for such printing machines.

In addition, the printing machine in this example has a maximum dimension of 10102
The apparatus is designed to process a sheet-like printing material with a minimum size of 0.times.720 mm and a minimum dimension of 540.times.360 mm, and the electron beam irradiation device 10 is also designed to irradiate the printing material within this range with an electron beam.

The electron beam generating section 12 of the electron beam irradiation device 10 mainly consists of an electron beam acceleration tube 20 and an elongated electron beam source (not shown) extending in the direction perpendicular to the drawing in the same manner as in FIG. 4 at the center thereof. The interior of the electron beam acceleration tube 20 is maintained at a high degree of vacuum in order to accelerate the electron beam. When a high voltage is applied between the electron beam source and the electron beam acceleration tube 20, the electrons generated by the electron beam source are accelerated downward.

The accelerated curtain-shaped electron beam passes through a metal foil (not shown) provided in the irradiation window 22 and is emitted into the cylinder 1.
4 is irradiated onto the substrate to be printed. The printing material irradiated with the electron beam is conveyed to the outside by a gripper bar 45 provided on a chain of the delivery section 38. Note that the distance between the metal foil of the irradiation window 22 and the surface of the cylinder 14 is approximately several centimeters.

As shown in FIG. 2, the cylinder 14 is provided with three glyph bar devices 24, 26, 28 along the circumference. These grip the leading edge of the substrate coming from the final unit 16 of the printing press in FIG. Although the rear end of the printing material is not gripped, the printed portion of the printing material can be protected by means described below.

Cylinder 18.36 of the final unit 16 in the printing press
, a cylinder 14 installed below the electron beam irradiation device 10,
And the conveyance cylinder 30 provided between these,
They rotate while maintaining a constant relationship so that printing materials are delivered to each other at predetermined rotational positions. Further, the diameters of these cylinders are designed to a predetermined value as will be described later so that such delivery is possible.

By the way, when the electron beam irradiation device 10 irradiates the electron beam, X-rays harmful to the human body are generated.

Therefore, it is necessary to take measures to prevent XvA from leaking to the outside. For this purpose, the outer periphery of the cylinder 14 is provided with shielding means 32 made of metal such as lead. The distance between the shielding means 32 and the surface of the cylinder 14 is reduced to about 1 cm to improve shielding efficiency. Furthermore, a shielding means 14b is provided inside the thickness 14a of the cylinder 14 along the cylinder. These shielding means can prevent X-rays generated when an electron beam collides with a metal or the like from leaking to the outside, or can attenuate the level of X-rays to the extent that they do not harm the human body. Furthermore, a passage 34 is provided between the inner shielding means 14b and the cylinder 14 to allow water to cool the cylinder 14 to flow therethrough.

Further, in the final unit 16, a cylinder 36 for applying EB ink rotates once, thereby performing predetermined printing on the printing material. Therefore, the diameters of the transport cylinder 18, 30 and the electron beam irradiation cylinder 14 need to be an integral multiple of the diameter of the cylinder 36 in order to synchronize the timing with the transport by the cylinder 36. In this embodiment, the diameter of the cylinder 36 for coating in the final unit 16 is 290 mm, while the diameter of the cylinder 18 for conveyance is twice this, 580 mm.
The cylinder 14 for electron beam irradiation is 870 mm, which is three times the size. However, even if the diameter of the cylinder 14 is made an integral multiple of the diameter of the cylinder 36, there is a certain limit to the diameter of the cylinder 14 for the following reason. That is, cylinder 1
If the diameter of 4 is too small, the sheet-like printing material used as the container for the beverage product is somewhat hard, so it will be difficult to bend it along the cylinder 14, and the end will spring up, causing the printed part to become a shielding means. There is a risk of contact with 32. Furthermore, it becomes impossible to uniformly irradiate the substrate with the electron beam. Furthermore, since the cylinder 14 must come into contact with the front and rear conveyance cylinders at the position indicated by Y in FIG.
2 becomes small, and X-ray shielding becomes insufficient.

On the other hand, if the diameter of the cylinder 14 is too large, a large amount of lead must be used for the shielding means 32 and 14b to prevent leakage of X-rays, which increases cost and increases the weight of the device. . Conversely, the shielding means 3
2, when the same amount of lead is used, if the diameter of the cylinder 14 is too large, the opening angle α connecting the center of the cylinder 14 and the two ends of the shielding means 32 will become small, making it difficult to sufficiently shield X-rays. I won't be able to do that.

Considering the above points, the diameter of the cylinder 14 is 400 m.
It is desirable that the distance be within the range of 2000 mm from m, and the value of 870 mm in this embodiment is also within this range.

The shielding means 32 is provided with a large number of injection holes 32a for injecting nitrogen gas toward the cylinder 14 from the outside. When curing EB ink by irradiating the printing material with an electron beam after printing, it is necessary to eliminate oxygen in the irradiation area, so a replacement nitrogen supply device (which replaces the inside of the irradiation area with nitrogen gas) is required. (not shown) is provided in the irradiation section. The injection hole 32a of the shielding means 32 reliably eliminates oxygen in the irradiation section together with or in addition to this nitrogen supply device for substitution.

Furthermore, this injection of nitrogen gas also plays the role of preventing the printing material from coming into contact with the shielding means 32. That is,
The leading edge of the substrate is gripped by a glyph bar device 24, 26, 28 provided on the cylinder 14, but no means are provided for gripping the trailing edge. but,
By injecting nitrogen gas at high speed toward the cylinder 14 from a large number of injection holes 32a provided in the shielding means 32, the printing material is prevented from contacting the shielding means 32 of the cylinder 14 due to the jetting pressure.

As described above, the object to be marked III in the electron beam irradiation device 10 is transported by the cylinder 14 as in conventional printing machines, so that when a transport belt is used as in the past, Unlike this, there is no particular limit to the speed at which the substrate is conveyed.

On the other hand, an electron beam irradiation device has originally high processing capacity and can perform the curing process of EB ink at a speed comparable to that of a printing and submachine. Therefore, by providing a printing press with the cylinder 14 and electron beam irradiation device 10 as described above, the overall processing speed from the printing process to the curing process of the EB ink can be greatly improved. Specifically, in contrast to conventional electron beam irradiation equipment, where the processing speed was limited to about 100 m/min because the printing material was transported by a conveyor belt, in this example, the processing speed was limited to about 100 m/min, which is the same as the processing speed of the printing process. A processing speed of about 200 m/min can be achieved.

Furthermore, when a conveyor belt is used as in the past, extra space is required for installing the electron beam irradiation device, but as in the above embodiment, the cylinder 14 is used to convey the printing material in close contact with the cylinder 14. With this configuration, the installation space for the electron beam irradiation device can be smaller than that of the conventional one.

In this embodiment, the case where the diameter of the cylinder 14 is 870 mm has been described, but the diameter is not limited to this value as long as it is within the range that satisfies the conditions described above.

〔Effect of the invention〕

As explained above, according to the present invention, the conveyance of the printing material in the electron beam irradiation device is synchronized with the conveyance in the printing machine, and is gripped by the electron beam irradiation cylinder in the same manner as in the printing machine. Since the electron beam irradiation is carried out on this electron beam irradiation cylinder, the EB ink can be cured at a processing speed equivalent to that of a printing machine, and the transport for transporting the printing material is Since the belt is no longer required, the space required by the electron beam irradiation device can be reduced. Furthermore, by setting the diameter of the electron beam irradiation cylinder to a value within the above-mentioned range, the printing material can be moved along the electron beam irradiation cylinder. By bending the sheet, for example, the bounce of a sheet-shaped printing material used as a beverage container is minimized to prevent the printed part from coming into contact with other objects and causing scratches, and it is also easy to shield to prevent leakage of XvA. It is possible to provide a sheet-fed printing machine that can perform

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the main parts of a sheet-fed printing press that is an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the electron beam irradiation device in FIG. 1, and FIG. The figure is a schematic sectional view of an example of a conventional sheet-fed printing press, and FIG. 4 is a schematic sectional view of another example of a conventional sheet-fed printing press. 10... Electron beam irradiation device, 2... Electron beam generating unit, 4.1B, 30.36... Cylinder, 6... Final unit of printing press, 0... Electron beam accelerator tube, 22 ...irradiation window, 4.26.
28... Gripper device, 2... Shielding means, 38...
...Delivery Department. Deto Iwasaki Electric Co., Ltd. Agent Patent Attorney Han 1) Masao

Claims (1)

[Claims] A sheet-fed printing device that rotates parallel to the cylinder is installed at a later stage of the sheet-fed printing means that sequentially passes a plurality of processes on the sheet-like printing material while the printing cylinder carries it, and performs predetermined printing using the printing cylinder. An electron beam irradiation means is provided which includes an electron beam irradiation cylinder having a shaft and rotates the electron beam irradiation cylinder to irradiate the printing material with an electron beam, and the diameter of the electron beam irradiation cylinder is adjusted. A sheet-fed printing machine, characterized in that the diameter is an integral multiple of the diameter of the printing cylinder, and the value is between 400 mm and 2000 mm.