JP2000108536A - Method and apparatus for cutting lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus for cutting a photosensitive lithographic printing plate punched scraps of which are not caught between punching lower blades capable of obtaining a corner slope to be necessary even in the case of a narrow width of a trimming scrap. SOLUTION: At the time of cutting a trimming part of a web 12 with a trimming upper blade 22 and a trimming lower blade 24, the part to become trimming scraps 12A is supported by a support ring 40, thereby obtaining a corner slop height to be necessary. Since a coring holder 48 is disposed between the two boring lower blades 36 so that punched scraps 12B are bent, the scraps are not caught between the blades 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cutting a lithographic printing plate.

[0002]

2. Description of the Related Art A photosensitive lithographic printing plate (hereinafter, referred to as a "PS plate") is generally formed on a sheet-like or coil-like aluminum plate by, for example, graining, anodizing, silicate treatment, and the like.
Perform surface treatment such as other chemical conversion treatment alone or in appropriate combination, and then apply a photosensitive solution, after performing a drying treatment,
It is manufactured by cutting to the desired size.

The PS plate is subjected to plate making processes such as image exposure, development processing, gumming, etc., is set in a printing machine, and is coated with ink to print a developed image on paper.

By the way, as shown in FIG.
(The PS plate before cutting is called a “web”.) The ears are cut by a slitter 92 composed of an upper blade 88 and a lower blade 90, but the ink adhering to the cutting unit stains the printing paper surface. ,
The printed product may lose value.

[0005] For this reason, a method of shaving burrs at the cut portion of the PS plate with a file or a knife has been adopted (Japanese Patent Publication No. 57-57).
In this case, the PS plate must be processed one by one, which is not suitable for mass processing. Further, the ink is entangled with the shaved portion, and eventually the printing paper surface is stained with the ink.

Further, there is a method of applying a desensitizing solution to the cut surface of the PS plate (Japanese Patent Publication No. 62-61946), but the PS plates are stuck together, and handling is troublesome.

On the other hand, there is a method in which burrs of the cut portion are not generated on the printing surface side of the PS plate (Japanese Patent Application Laid-Open No. 62-19315), but stains are generated depending on printing conditions.

On the other hand, a method has been proposed in which the cut portion of the PS plate is formed in a shape bent to the opposite side to the printing surface to thereby prevent the printing paper surface from being stained with ink (Japanese Patent Laid-Open No. 7-327).
It is known that, as shown in FIG. 4, the sagging height h of the cut portion is 20 μm to 100 μm (JP-A-8-192079).

In order to form such a sagging height, the distance between the upper blade 88 and the lower blade 90 (hereinafter referred to as "clearance L", and the clearance is exaggerated in the drawings) is 30 .mu.-100 .mu.m. However, in practice, if the width of the ear dust 12A to be cut becomes narrow, the required sagging height cannot be obtained.

On the other hand, in the cutting process, the two webs 12
In this case, the middle upper blade 96 and the middle lower blade 94 simultaneously with the ears.
In this case, the central portion is cut off, but the plate-shaped middle scrap 12B may be caught between the middle lower blades 94 and may not come off, causing a trouble.

[0011]

In view of the above facts, the present invention can obtain the required sagging even when the width of the ear dust is narrow, and the hollow dust is sandwiched between the lower blades. The task is to avoid such problems.

[0012]

According to the first aspect of the present invention, the edge of the lithographic printing plate is cut by a slitter composed of an upper blade and a lower blade while conveying the lithographic printing plate. At this time, the required sagging height can be obtained by supporting the ear portion serving as ear shavings.

According to the second aspect of the invention, the edge of the lithographic printing plate is cut by a slitter composed of an upper blade and a lower blade while the lithographic printing plate is being conveyed. At this time, the receiving means that rotates integrally with the lower blade reliably supports the ears of the lithographic printing plate, so that the required sagging height can be obtained, and the lithographic printing plate can be smoothly transported. .

The distance between the receiving means and the lower blade is such that the upper blade can enter and is narrower by a predetermined amount than the ear width of the ear dust (the distance is preferably at least 1 mm narrower than the ear width). If the distance between the receiving means and the lower blade is wider than the width of the ear, the required sagging height cannot be obtained.

According to the third aspect of the present invention, the receiving means includes:
It is located near the rear of the lower blade. Since the receiving means supports the ear portion serving as ear shavings, a required sagging height can be obtained.

According to the fourth aspect of the present invention, the lithographic printing plate is supported by the two lower punching blades arranged at a predetermined distance, and the two lithographic printing plates are punched out by the upper punching blade. It is cut to. Here, since the hollowed out chips are bent, the distance between the hollowed down blades is shorter than the distance between the hollowed down blades, so that they are not caught between the hollowed down blades.

According to the fifth aspect of the present invention, the planographic printing plate is supported by the two centering lower blades arranged at a predetermined distance from each other, and two planographic printing plates are centered by the centering upper blade. It is cut to. A blanking holder is arranged between the blanking lower blades to support and bend the blanks pressed by the blanking upper blades.

As a result, the width of the blank is smaller than the distance between the hollow lower blades and is not interposed between the hollow lower blades.

According to the sixth aspect of the present invention, the guide means protrudes and retracts from the upper surface of the lithographic printing plate to guide the hollow chips downward. The guided scrap is guided to the transport roller through the cylindrical body and is pinched. For this reason, every time the web is hollowed out, there is no need to manually hold the hollow scraps between the transport rollers.

The hollow chips conveyed to the rotary cutter and the like by the conveying rollers are cut into small pieces and are conveyed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. (Outline of Cutting Line) As shown in FIG. 1, a feeder 14 for sending out a roll-shaped web 12 is located upstream of a cutting line in which a slitter 10 (cutting device) according to the present embodiment is disposed.
Are arranged. The web 12 sent from the feeder 14 is overlapped with the interleaf paper 18 at the feed roller 16 and is brought into close contact by charging, and reaches the notcher 20.

The notcher 20 pierces the edge of the web 12 and the upper trimming blade 22 and the lower trimming blade 24 of the slitter 10 (see FIG. 2).
2 can be moved in the width direction. Thereby, the trimming width (width size) of the web 12 can be changed while continuously cutting (cutting the slip sheet and the web).

As described above, the length of the web 12 having the predetermined trimming width is detected by the length measuring device 26,
At the specified timing, the running cutter 28 cuts the web 12 to produce a PS plate 30 of a set size.

Next, the PS plate 30 is sent to the stacking unit 34 by the conveyor 32, and after stacking a predetermined number of sheets, the PS plate 30 is packed with cardboard, skids, or the like and shipped. Note that, depending on the packaging form, slit cutting may be performed without interleaving paper. (Structure of slitter) As shown in FIG. 2, the slitter 10 includes a pair of middle lower blades 3 provided on a base 42 at the center.
6, a spacer ring 38 is disposed outside the lower ring, and a trimming lower blade 24 is disposed outside the spacer ring 38. The middle lower blade 36, the spacer ring 38, and the lower trimming blade 2
The web 12 is transported on the web 4.

Above the lower trimming blade 24, a dish-shaped upper trimming blade 22 is arranged.
4 which is turned in a direction opposite to 4 and is conveyed
Cut out the ears in the width direction of 2. The upper trimming blade 22 and the lower trimming blade 24 are formed of a material SKH51, and are attached to a base 46 that moves in the width direction of the web 12 along the rail 44. The blade may be made of a material such as powdered high-speed steel or carbide.

As shown in FIG. 3, the clearance L between the upper trimming blade 22 and the lower trimming blade 24 ranges from 30 μm to 10 μm.
In order to prevent burrs B from being generated on the photosensitive layer P (in this example, the upper surface side) as shown in FIG. Located to the side.

Further, on the outside of the trimming lower blade 24,
A receiving ring 40 having substantially the same diameter is provided coaxially, and rotates integrally with the trimming lower blade 24. The corner of the receiving ring 40 is chamfered to have a truncated cone shape, and forms a gap X between the lower trimming blade 24 and the upper trimming blade 22. This X has a size that the trimming upper blade 22 can bite, and is smaller than the ear width m of the ear dust 12A of the web 12 by 1.0 mm or more.

Further, in a state where the upper trimming blade 22 is lowered and the web 12 is cut by the lower trimming blade 24, the distance Y () between the corner 40A of the receiving ring 40 and the outer peripheral surface of the upper trimming blade 22 is determined. The distance between the extension of the corner 40A and the point at which the outer surface intersects) is equal to or greater than the thickness t of the web 12. The distance Y changes depending on the shape of the upper trimming blade.

With such a configuration, the receiving ring 40
However, since the edge of the web 12 is held at the time of cutting, it is possible to obtain a sagging height h necessary for preventing ink attached near the cutting from soiling the printing paper surface. In addition, by setting the value of X to a size that allows the upper trimming blade 22 to bite, it is possible to prevent ear chips from being caught between the upper trimming blade 22 and the receiving ring 40 and the blade from being worn.

Here, the relationship between the sag height h and the gap X is measured under the following conditions.

That is, the lower trimming blade 24 is a flat blade having a tip angle of 90 degrees and a blade diameter of φ200, the upper trimming blade 22 is a blade having a diameter of φ200 and having a 60 ° clearance leaving a right-angled portion with a tip of 1 mm. Uses a 45-degree chamfer and defines the distance X from the trimming lower blade 24 by the amount of chamfer.

As a material for evaluation, a negative PS plate VNN manufactured by Fuji Photo Film Co., Ltd. was used, and the thickness t was 0.3 mm.
A web having a width of m is cut into a width of 800 cm. Further, the clearance L between the lower trimming blade 24 and the upper trimming blade 22 was set to 30 μ, and the sagging height h was measured by a surface profile measuring device manufactured by Tokyo Seimitsu.

[0033]

[Table 1] As can be seen from the above table, the gap X is 1.0 mm from the ear width m.
If it is narrower than above, target sagging height (20-100μ)
Can be obtained.

By arranging the roller 70 as a receiving ring for the ear dust 12A on the downstream side of the lower trimming blade 24 as shown in FIG. 5, the range in which the upper trimming blade 22 can enter can be considered. , The interval between the roller 70 and the trimming lower blade 24 can be set. Note that a roller that receives the entire width of the web 12 may be provided instead of the roller 70.

On the other hand, as shown in FIG. 2, a hollow holder 48 is disposed between the hollow lower blades 36, and is rotatable together with the hollow lower blade 36. The hollow holder 48 has the shape of an abacus ball, and the outer diameter of the flat surface 48A at the center is smaller than the blade diameter of the hollow lower blade 36 by about 0.2 mm (FIG. 6D). reference).

A beam 50 is provided above the hollow blade 36.
Is located therefrom. The middle punching upper blade 52 is a single fixed blade having an annular flat groove in the center, and enters between the centering lowering blades 36 to hollow out the central portion of the web 12.

As described above, the necessary sagging height h can be obtained at the center cut portion of the web 12 by the hollowing holder 48, and the hollow blank 12B is bent into a trapezoidal shape, and the hollow lower blade 36 Is smaller than the distance in the axial direction, so that there is no possibility that the gap will not be caught between them.

It is to be noted that the shape of the hollow upper blade 52 shown in FIG. 6A is not limited to the shape shown in FIG.
The two fixed blades 56 may be used as middle-cutting upper blades, or may be two gobel type fixed blades 58 shown in FIG. 6C. The fixed blade 58 is urged by a disc spring 60, so that the clearance between the fixed blade 58 and the middle lowering blade can be made close to zero.

The shape of the hollow holder 48 shown in FIG. 6D is not limited to the shape of the hollow holder 48 shown in FIG. 6E. The scrap 12B may be used, or a hollow holder 66 provided with a flange having a trapezoidal cross section from the outer peripheral surface of the disk shown in FIG. 6 (F). Further, as shown in FIG. The hollow blank holder 68 having a sandwich structure made of different disks may be used. In short, it is only necessary that the hollow blank can be made shorter than the axial spacing of the hollow blank blade 36.

As shown in FIGS. 7 and 8, a tubular shooter 72 is disposed downstream of the middle and lower blade 36 with an opening inclined to the lower surface of the web 12. An air cylinder 74 is mounted on the outer peripheral surface of the shooter 72. The rod 76 of the air cylinder 74 has a lower end positioned inside the shooter 72, and a hollow extraction guide 78 having a curved upper end fixed via a bracket 81.

In this configuration, the air cylinder 74 is driven so that the hollow guide 78 protrudes obliquely upward and the web 12
, And the middle chip 12B can be guided downward. The middle scraps 12B are sent to a chopper (not shown) by the conveying rollers 80, are cut into small pieces, and are then carried out to the storage box 84 by the conveyor 82 (see FIG. 1).

As described above, when the web needs to be hollowed out, by providing the hollowing-out guide 78 and the shooter 72 that project from below and guide the hollowed-out waste to the transport roller 80, the worker can handle the hollowed-out waste. Each time, it is not necessary to manually pinch the tip of the hollow waste to the transport roller 80.

As shown in FIG. 7, a transport roller 83 is also provided in the trimmer section, so that the nipped
A is pinched and guided, sent to a chopper (not shown), and cut into small pieces.

[0044]

According to the present invention, the above configuration is provided.
According to the second aspect of the present invention, it is possible to obtain a sag height required for a lithographic printing plate. According to the third aspect of the present invention, no ear dust is caught between the upper blade and the receiving means, the blade is less likely to be worn at portions other than the cut portion, and a required sag height is obtained.

According to the fourth and fifth aspects of the present invention,
Since the hollow chips are hollowed out, they are not caught between the hollow blades. According to the sixth aspect of the present invention, it is not necessary to pinch the leading end of the hollow chips with the transport roller every time hollowing is performed.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a cutting line provided with a cutting device according to the present embodiment.

FIG. 2 is a front view of the cutting device according to the embodiment.

FIG. 3 is an explanatory diagram illustrating a cutting unit of the cutting device according to the embodiment.

FIG. 4 is an enlarged view showing sagging and burrs of a PS plate.

FIG. 5 is a perspective view showing a cutting unit of a cutting device according to a modification.

FIG. 6 is a front view showing a variation of a middle blank upper blade and a middle blank holder.

FIG. 7 is a perspective view showing a cutting-out guide means of the cutting device according to the present embodiment.

FIG. 8 is a side view showing the centering guide means of the cutting device according to the present embodiment.

FIG. 9 is a front view of a conventional cutting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Web (lithographic printing plate) 12A Ear dust 12B Middle scraping 22 Trimming upper blade (upper blade) 24 Trimming lower blade (lower blade) 40 Receiving ring (receiving means) 48 Centering lower blade 54 Centering holder 52 Centering upper Blade 70 Roller 72 Shooter (cylindrical body, guide means) 74 Air cylinder (guide means) 78 Internal guide (guide means)

Claims (6)

[Claims] 1. A lithographic printing plate cutting method for cutting while transporting the lithographic printing plate, wherein when a slitter composed of an upper blade and a lower blade cuts an ear portion of the lithographic printing plate, an ear which becomes ear dust. A method for cutting a lithographic printing plate, comprising supporting a part. 2. A lithographic printing plate cutting apparatus for cutting while transporting a lithographic printing plate, comprising: a slitter comprising an upper blade and a lower blade for cutting an edge of the lithographic printing plate; and rotating integrally with the lower blade. A cutting device for a lithographic printing plate, comprising a receiving means, wherein a distance between the lower blade and the receiving means is such that the upper blade can be inserted therein and is smaller by a predetermined amount than an ear width of ear shavings. 3. The apparatus according to claim 2, wherein said receiving means is located near a rear portion of said lower blade, and supports an ear portion serving as ear dust when said slitter cuts an edge portion of said lithographic printing plate. 3. The apparatus for cutting a lithographic printing plate according to 2. 4. A method for cutting a lithographic printing plate, wherein a lithographic printing plate supported by two lower punching blades arranged at a predetermined distance is punched out by an upper punching blade and cut into two sections. A method for cutting a lithographic printing plate, comprising bending the hollow waste of the lithographic printing plate that has been hollowed out. 5. A lithographic printing plate cutting device which cuts out a lithographic printing plate supported by two middle-draining lower blades arranged at a predetermined distance and cuts the lithographic printing plate into two strips, A lithographic printing plate, comprising a hollow holder that is disposed between the lower hollow blades and that supports and bends the hollow chips of the lithographic printing plate that is hollow and pressed by the upper hollow blade. Cutting equipment. 6. A guide means which protrudes and retracts from the upper surface of the lithographic printing plate and guides the hollow chips downwardly, and a cylindrical body which guides and holds the hollow chips guided by the guide means to a transport roller. The lithographic printing plate cutting device according to claim 5, comprising: