JP2006023532A - Development apparatus for printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development apparatus for a printing plate in which an unexposed portion of a printing plate not cured is peeled and removed with a rotary brush device and chips of a photosensitive film or the like remaining in the bristles of the brush can be easily removed. <P>SOLUTION: The development apparatus for a printing plate develops a printing plate by leaving an image recording layer (photosensitive film) cured by exposure while removing an unexposed portion not cured. The apparatus is equipped with: a rotary brush device to rub a printing plate to peel and remove an unexposed portion; and a carrying device to carry the printing plate to pass through at least the rotary brush device. The rotary brush device has a variable speed gear means which can switch between low-speed rotation and high-speed rotation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing plate developing apparatus, and more specifically, a printing plate development that develops a printing plate by leaving a portion of an image recording layer (photosensitive film) cured by exposure and removing an unexposed portion that has not been cured. The present invention relates to a printing plate developing apparatus having an improved brush cleaning method for removing debris and the like of a photosensitive film adhering to a brush used for removing the above-mentioned uncured unexposed portion by peeling and removing the film.

  In general, a lithographic printing plate has a surface composed of an oleophilic image portion and a hydrophilic non-image portion. In the lithographic printing, dampening water and oil-based ink are alternately applied to the plate surface, Using the property that oil and oil repel each other, the hydrophilic non-image area is dampened with water (ink non-reception area), and ink is received only in the oleophilic image area before printing on paper, etc. This is a printing method in which printing is performed by transferring ink to a medium (printed body).

  In order to produce this lithographic printing plate, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support such as an aluminum plate has been widely used. ing. Usually, this lithographic printing plate precursor is exposed and cured through an original image such as a lithographic film, and then removed by dissolving the unexposed (uncured) image recording layer with an alkaline developer or an organic solvent, A lithographic printing plate has been produced by a method of forming an image portion leaving only the exposed lipophilic image recording layer.

  In such a conventional lithographic printing plate precursor making process, the image recording layer is exposed and cured, and then the unnecessary image recording layer is removed by dissolution with an alkaline developer or an organic solvent, thereby providing a hydrophilic support. Although it is necessary to perform a process for exposing the surface of the film, it is mentioned as one of the problems to make such a wet process unnecessary or simplified. In particular, in recent years, due to considerations for the global environment, disposal of waste liquid discharged with wet processing has become a major concern for the entire industry, and there is an increasing demand for solutions to the above problems.

  On the other hand, as one of the simplified plate-making methods that are friendly to the global environment, only the unexposed image recording layer swells due to dampening water or an ink solvent, and the cohesive force is reduced or supported. Use a lithographic printing plate precursor with low adhesion to the body, use the printing machine as it is, attach the exposed lithographic printing plate precursor to the roll of the printing machine, and use the dampening water or ink solvent on the image recording layer A plate-making method (on-press development method) has been developed in which a mechanically unexposed image recording layer is peeled off and removed by contact between a lithographic printing plate precursor and a roller or a blanket after supply .

  However, in the plate making method (on-press development method) described above, it is very difficult to reliably recover the mechanically removed photosensitive film residue, and a part of the removed photosensitive film residue is partially removed from the printing machine. It will splash into the machine and contaminate the surroundings, or will adhere to the hydrophilic substrate of the lithographic printing plate from which the unexposed image recording layer (photosensitive film) has been peeled off and removed, causing development unevenness and scratches. It was.

  For this reason, the exposed lithographic printing plate precursor is rubbed with a dedicated brush, and the unexposed image recording layer is mechanically peeled off and removed. However, when the unexposed image-recording layer is peeled off or removed by rubbing with a brush, the debris of the photosensitive film removed between the bristles of the brush accumulates. The lithographic printing plate that has been peeled off and removed from the film is scattered on the hydrophilic substrate and reattached, causing development unevenness and scratches. Need to be removed.

  The residue of the photosensitive film sandwiched between the brush bristles cannot be easily removed by a cleaning method such as normal stirring and cleaning.To ensure completeness, the brush is taken out of the machine and subjected to ultrasonic cleaning. It was necessary to adopt a time-consuming cleaning method.

In addition, as a technique relevant to this, patent document 1 and patent document 2 can be mentioned. Here, Patent Document 1 discloses that a PS plate immersed in a developer is rubbed with a rotating brush roller to promote development, and Patent Document 2 discloses that a color filter is washed with a rotating brush. It is disclosed.
JP-A-6-332193 Japanese Patent Laid-Open No. 7-171515

  The object of the present invention is to solve the above-mentioned problems of the prior art, and to peel and remove the unexposed portion (that is, the uncured portion) of the printing plate after the exposure by the printing plate exposure device with a rotating brush device. An object of the present invention is to provide a printing plate developing apparatus having a rotating brush device that can easily remove the residue of the photosensitive film accumulated between the brush hairs.

  In order to solve the above problems, a printing plate developing apparatus according to the present invention leaves an image recording layer (photosensitive film) cured by exposure, removes uncured unexposed portions, and develops the printing plate. A developing brush that rubs the printing plate to remove and remove the unexposed portions; and a conveying device that conveys the printing plate so as to pass at least the rotating brush device; And the rotary brush device has a speed change means capable of switching between low speed rotation and high speed rotation.

  Here, the low-speed rotation of the rotating brush device is a rotation speed in an unexposed portion removing step in which the unexposed portion is removed by removing the unexposed portion by rubbing the printing plate exposed and cured with the brush with a brush. The high-speed rotation of the rotary brush device is preferably a rotation speed in a brush cleaning process for removing impurities such as residue of the photosensitive film adhering to the brush.

  The rotary brush device preferably includes a rotary brush that removes the unexposed portion by rubbing the photosensitive and cured printing plate, and a backup roller that supports the printing plate. It is preferable that an apparatus has a water supply nozzle arrange | positioned above the said rotating brush.

Further, in the brush cleaning step, it is preferable that a baffle plate is disposed at a position where the brush rotates at a high speed and abuts on an outer periphery of the brush, and the baffle plate is a blade-shaped plate or punched. It is preferable that it is a plate.
Note that the printing plate to be applied in the present invention is a so-called on-press developable PS plate, regardless of whether it is negative or positive, thermal type, photopolymer type or the like.

  According to the present invention, in the brush cleaning step, the debris of the photosensitive film accumulated between the bristles of the brush can be easily removed by rotating the brush at a high speed. In addition, by arranging the baffle plate at a position where it abuts on the outer periphery of the brush, it is possible to easily remove photosensitive film residue and the like accumulated between the bristles of the brush, and the baffle plate is a blade-like plate. Alternatively, the effect is further increased when the punched plate is used.

Embodiments of the present invention will be described below with reference to the drawings.
1 is a front view of a printing plate developing apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged front view of a rotating brush apparatus of the printing plate developing apparatus, and FIG. 3 is an embodiment of a relationship between the rotating brush and a baffle plate. FIG. 4 is an enlarged front view showing another embodiment of the relationship between the rotating brush and the baffle plate, and FIG. 5 is a development view showing one embodiment of the shape of the baffle plate shown in FIG. 6 is a development view showing another embodiment of the shape of the baffle plate shown in FIG.

  The printing plate developing device of the present invention has a printing plate exposure device (not shown) on the upstream side, and as this printing plate exposure device, any conventional technique for exposing and curing an image recording layer For example, a recording light such as a laser beam modulated according to digitally processed image information is projected onto a printing plate precursor having an image recording layer. As a result, a predetermined image is exposed to the printing plate precursor, and the photosensitive film in the portion irradiated with the recording light is cured.

  The printing plate 2 exposed in this printing plate exposure apparatus and cured only on the exposed part is supplied to the printing plate developing apparatus 4 of the present invention shown in FIG. The printing plate developing apparatus 4 according to the present invention is a device that develops the printing plate 2 by mechanically removing uncured unexposed portions with a rotating brush, and rubs the printing plate 2 to peel off the unexposed portions. A rotary brush device 6 that removes the film by removing the film, a gum solution applying device 8 that applies the gum solution to the printing plate 2 that has been removed by peeling and removing the unexposed portion, and a gum that is applied to the printing plate 2 It comprises a gum solution drying device 10 for drying the solution, and a conveying device 12 for conveying the printing plate 2 from the rotary brush device 6 to the gum solution drying device 10 through the gum solution application device 8.

  The rotating brush device 6 has a water tank 14, and inside the water tank 14, two sets of conveying rollers 16 constituting a conveying device 12 that sandwiches and rotates the printing plate 2 and conveys the printing plate 2. The rotary brush 18 and the backup roller 20 are provided at the intermediate position. The rotating brush 18 rubs the exposed and cured printing plate 2 to remove unexposed portions, and rotates at a predetermined number of rotations described later. Further, the backup roller 20 supports the printing plate 2 from the back when the surface of the printing plate 2 is rubbed with the rotating brush 18 to remove the unexposed portion, and has the same peripheral speed as the conveying speed of the printing plate 2. Rotate.

In this embodiment, the rotary brush 18 is a pile brush having an outer diameter of φ70 mm, and has a brush bristle wire diameter of 28 μm, a length of 5 mm, and a flocking density of 25,296 / cm ^2. ing. However, the brush is not limited to this, and it is desirable to appropriately change the diameter and length of the hair, the flocking density, etc. according to the properties such as hardness and adhesiveness of the cured image recording layer. .

  Further, the brush is not limited to a pile brush, and for example, a channel brush attached to a rotating shaft can be suitably used, and a twisting brush or an embedded brush can also be used. It is desirable to use any brush that is suitable for rubbing and removing unexposed areas. Further, a baffle plate 44 is provided at a position in contact with the outer periphery of the rotating brush 18. The baffle plate 44 is used only for a brush cleaning process described later, and is usually retracted and retracted to a position indicated by an imaginary line.

  The rotational speed of the rotary brush 18 is low and high speed by any speed change means, for example, a variable speed motor, or any speed reduction device (not shown) having a clutch means and capable of switching a reduction ratio. In this embodiment, the rotation speed of the rotary brush 18 is set to 200 rpm for low speed rotation and 900 rpm for high speed rotation.

  Here, although the details will be described later, in the unexposed portion removing step of removing the unexposed portion by removing the unexposed portion by rubbing the printing plate which has been exposed and cured by exposing the image with a brush, the rotating brush of the rotating brush device 6 is used. In the brush cleaning process in which the photosensitive drum 18 is operated at a low speed and the residue of the photosensitive film attached to the rotary brush 18 is removed, the rotary brush 18 of the rotary brush device 6 is operated at a high speed.

  The water tank 14 of the rotary brush device 6 is provided with a water supply nozzle 22 above the rotary brush 18, a water supply port 24 on the side surface of the water tank 14, and a drain port 26 on the lower surface. Then, water is circulated by the water supply pump 28 to spray water from the water supply nozzle 22 to the image recording layer, and the unexposed image recording layer is swollen by the action of this water to reduce the cohesive force, or the adhesive force to the support. By reducing the thickness of the printing plate 2, the unexposed image recording layer can be easily peeled off and removed from the printing plate 2, and the surface of the printing plate 2 is rubbed with the rotating brush 18 to remove the unexposed image. The recording layer is peeled off and removed. Further, the filter 30 provided on the downstream side of the water supply pump 28 removes the residue of the photosensitive film in the brush cleaning process described later.

  The gum solution application device 8 applies a gum solution to the surface of the printing plate 2 from which the unexposed image recording layer has been peeled and removed, and protects the hydrophilic surface. And a back-up roller 34 and a gum solution supply container 36 for supplying the gum solution to the gum solution application roller 32. Then, a gum solution dropped from the gum solution supply container 36 by an appropriate amount is applied to the surface of the printing plate 2 by the application roller 32. At this time, both the rotation speeds of the application roller 32 and the backup roller 34 rotate at the same peripheral speed as the conveyance speed of the printing plate 2.

  The gum solution drying device 10 heats and drys the gum solution applied to the surface of the printing plate 2 by the gum solution coating device 8 and supports the cover 40 covering the periphery of the heater 38 and the printing plate 2 from below. And a guide roller 42 for guiding. And the printing plate 2 which passed this gum liquid drying apparatus 10 is discharged | emitted by storage apparatuses, such as a storage tray which is not shown in figure.

  Since the printing plate developing apparatus 4 of the present invention is configured as described above, in the unexposed portion removing step for removing the unexposed portion of the printing plate 2 by peeling and removing the film, the printing plate exposure is not shown. The printing plate 2 exposed and cured by the apparatus is supplied by the upstream conveying roller pair 16 and swells the unexposed image recording layer by the action of water supplied from the water supply nozzle 22 to reduce the cohesive force. Alternatively, the adhesive strength with the support is lowered, and the surface of the printing plate 2 is rubbed with the rotating brush 18 of the rotating brush device 6 to remove and remove the unexposed image recording layer. At this time, the strength to scrape off the unexposed image recording layer can be changed by a method of adjusting the pressure for pressing the rotating brush 18 against the surface of the printing plate 2 by lowering the rotating brush 18.

  In this embodiment, as described above, a pile brush having an outer diameter of φ70 mm, a wire diameter of 28 μm, and a length of 5 mm is used, the rotational speed of the rotating brush 18 is 200 rpm, and the feeding speed of the printing plate 2 is 3.5 mm. The unexposed image recording layer is peeled and removed as / min. At this time, since the rotating brush 18 rotates at a low speed of 200 rpm, most of the debris of the photosensitive film peeled off from the printing plate 2 is captured between the hairs of the rotating brush 18 and scattered around the printing plate 2. It will not adhere to the upper surface of the film and cause development unevenness and scratches.

  Then, the printing plate 2 from which the unexposed image recording layer has been peeled and removed is conveyed by the conveying device 12, the gum solution is applied by the gum solution applying device 8, and dried by the gum solution drying device 10. The developed printing plate 2 is stored in a storage device (not shown).

  In order to remove the residue of the photosensitive film captured between the bristles of the rotating brush 18 in the unexposed portion removing step, the printing plate developing apparatus 4 of the present invention is provided with a brush cleaning step. In this brush cleaning process, while supplying water to the rotating brush 18 from the water supply nozzle 22, the rotating brush 18 is rotated at a high speed of 900 rpm or more to reduce the cohesive force by swelling the residue of the photosensitive film by supplying water, or The adhesive force is reduced, and the residue of the photosensitive film trapped between the bristles of the rotating brush 18 is removed by centrifugal force, and the unexposed portion removing step is performed by the printing plate developing device 4. Can be done at any time when not.

  In this brush cleaning process, the photosensitive film residue trapped between the bristles of the rotary brush 18 is removed by centrifugal force, so that the photosensitive film residue is not scattered around the rotary brush 18. It is desirable to provide a cover 46 having an arbitrary shape used only in the brush cleaning process.

  In the brush cleaning process, it is further desirable to change the interval by vibrating the bristles of the rotating brush 18 in order to remove the debris of the photosensitive film that is strongly pinched and captured between the bristles of the rotating brush 18. For this reason, in this embodiment, a baffle plate 44 is prepared at a position where it abuts on the outer periphery of the rotating brush 18. As described above, the baffle plate 44 is retracted to a position indicated by an imaginary line in FIG. 1 in the unexposed portion removal process, and swings and is indicated by a solid line in FIG. 1 in the brush cleaning process. It advances to the position which contacts the outer periphery of the rotating brush 18 shown in an enlarged scale. At the same time, it is desirable that the cover 46 used only in the brush cleaning process is also arranged around the rotating brush 18.

  The baffle plate 44 may be simply a blade-shaped plate as shown in FIGS. 2 and 3, but in this case, as shown in FIG. Since the interval is changed only once by pressing and bending, in order to clean the rotating brush 18 in a short time, it is desirable to use a punched plate as shown in FIG. As the punching pattern of the punched plate, various patterns can be used as shown in FIGS.

  The debris of the photosensitive film removed from between the bristles 18a of the rotary brush 18 in the brush cleaning process scatters around, but eventually falls into the water 48 stored in the water tank 14 and is then supplied to the water tank by the water supply pump 28. 14 and is collected by the filter 30. The water that has been separated and cleaned by the filter 30 is again supplied from the water supply nozzle 22 to the rotating brush 18.

  Since the printing plate developing apparatus of the present invention is configured as described above, recording light is projected onto a printing plate precursor having an image recording layer coated with a photosensitive film, and the image is exposed to the recording light to expose the photosensitive film. In the printing plate developing apparatus, the unexposed portion of the printing plate that has passed through the printing plate exposure apparatus that cures and is exposed and cured by the printing plate exposure apparatus is peeled off and removed by a rotating brush apparatus. It is possible to provide a printing plate developing apparatus equipped with a rotating brush device that can easily remove the residue of the photosensitive film accumulated between the two.

1 is a front view showing an embodiment of a printing plate developing apparatus of the present invention. It is a front enlarged view of the rotating brush apparatus of the printing plate developing device. It is a front enlarged view which shows one Example of the relationship between a rotating brush and a baffle plate. It is a front enlarged view which shows the other Example of the relationship between a rotating brush and a baffle plate. It is an expanded view which shows one Example of the shape of a baffle plate shown in FIG. It is an expanded view which shows the other Example of the shape of a baffle plate shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Printing plate 4 Printing plate developing device 6 Rotating brush apparatus 8 Gum liquid application apparatus 10 Gum liquid drying apparatus 12 Conveying apparatus 14 Water tank 16 Conveying roller pair 18 Rotating brush 20 Backup roller 22 Water supply nozzle 24 Water supply port 26 Drain port 28 Water supply pump 30 Filter 32 Application roller 34 Backup roller 36 Gum liquid supply container 38 Heater 40 Cover 42 Guide roller 44 Baffle plate 46 Cover

Claims (6)

A printing plate developing apparatus for developing a printing plate by leaving an image recording layer (photosensitive film) cured by exposure, removing an uncured unexposed portion, and developing a printing plate,
A rotating brush device that rubs the printing plate to remove the unexposed portions;
A conveying device that conveys the printing plate so as to pass at least the rotating brush device;
The printing plate developing device, wherein the rotating brush device has a speed changer capable of switching between a low speed rotation and a high speed rotation. The low-speed rotation of the rotating brush device is a rotation speed in an unexposed portion removing step of removing the unexposed portion by rubbing the printing plate exposed and cured with the brush with a brush.
The printing plate developing apparatus according to claim 1, wherein the high-speed rotation of the rotary brush device is a rotation speed in a brush cleaning process for removing impurities attached to the brush. 3. The printing plate development according to claim 1, wherein the rotating brush device includes a rotating brush that rubs the printing plate to remove the unexposed portion, and a backup roller that supports the printing plate. apparatus. The printing plate developing apparatus according to claim 1, wherein the rotating brush device has a water supply nozzle disposed above the rotating brush.   3. The printing plate developing apparatus according to claim 2, wherein, in the brush cleaning step, the baffle plate is disposed at a position where the brush rotates at a high speed and contacts the outer periphery of the brush.   6. The printing plate developing apparatus according to claim 5, wherein the baffle plate is a blade-shaped plate or a punched plate.

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