JP5992854B2 - Planographic printing apparatus, planographic printing method, blanket - Google Patents

Description

  The present invention relates to a lithographic printing apparatus, a lithographic printing method, and a blanket, and more particularly to a lithographic printing apparatus, a lithographic printing method, and a blanket that transfer an image line image of ink onto a recording medium wider than the printing plate.

  In recent years, offset printing has become the mainstream commercial printing method. Offset printing is a method in which a printing plate, usually called a PS plate (Pre-Sensitized Plate), is prepared and dampening water and ink are supplied to the printing plate for printing. The printing plate is a lithographic plate, and the image area on the printing plate is treated to have an oleophilic surface, and the non-image area is treated to have a hydrophilic surface. When dampening water and ink are supplied to the printing plate, ink is attached to the image area and water is attached to the non-image area, and the ink is transferred from the printing plate to the paper through the blanket for printing. To do.

  Photosensitive lithographic printing plates using an aluminum plate as a support are commercially available as PS plates and are widely used. As a method for producing this PS plate, generally, a sheet-like or coil-like aluminum plate is subjected to surface treatment such as graining, anodizing, chemical conversion treatment, etc. alone or in combination, and then a photosensitive solution is applied and dried. A method of cutting to a desired size after performing is performed.

  On the other hand, in printing using a printing plate obtained by subjecting such a PS plate to image exposure and development, printing is performed on paper smaller than the width of the printing plate using a general commercial printing machine. In some cases, for example, printing is performed on printing paper larger than the width of the printing plate, such as newspaper printing. In the latter, the entire printing plate is treated as the printing surface.

  In the latter case, unnecessary ink adhering to the cutting edge (edge) of the printing plate is printed on the printing paper and becomes dirty, which may impair the commercial value of the printed matter.

  As a method for preventing smearing of the printing paper surface due to unnecessary ink on the printing plate, for example, in Patent Document 1, the edge of the printing plate has a width of 0.1 mm to 0.3 mm and a height of 20 μm to 100 μm. It is disclosed to be micron.

JP-A-10-35130

  However, as in Patent Document 1, even if the edge of the printing plate is gently inclined, the ink / water balance is adjusted or attached to the printing plate to prevent edge smearing due to the shape of the edge of the printing plate. It was difficult to set the pressure condition between the cylinder and the blanket cylinder, and it was sometimes impossible to prevent the ink adhering to the edge of the printing plate from being printed on the printing paper.

  The present invention has been made under such circumstances. In a lithographic printing apparatus, a lithographic printing method, and a blanket for transferring an image line image of an ink onto a recording medium wider than the printing plate, the shape of the edge of the printing plate is used. Select the edge shape of the plate by reducing the difficulty of adjusting the ink / water balance to the printing plate to prevent edge smearing and setting the pressure condition between the plate cylinder and the blanket cylinder where the printing plate is mounted. An object of the present invention is to provide a lithographic printing apparatus, a lithographic printing method, and a blanket that can prevent edge contamination.

  In order to achieve the above-mentioned object, the present invention provides a plate cylinder on which a printing plate is mounted on the peripheral surface, a blanket cylinder having a blanket to which an image line image of ink formed on the printing plate is transferred, and a blanket cylinder. And an impression cylinder that presses a recording medium having a width wider than a printing plate on which a line image on the blanket is transferred. The pressure applied to the blanket is A recessed portion is provided at the position of the blanket where the both end edges of the printing plate face each other so that the both end edges of the printing plate are lower than those other than the both end edges of the plate, or between the printing plate and the plate cylinder, Provided is a lithographic printing apparatus in which a plate is provided in a range other than both edges.

  In order to achieve the above object, the present invention provides a blanket cylinder transfer that transfers an image line image of an ink formed on a printing plate mounted on a peripheral surface of a plate cylinder onto the surface of the blanket attached to the blanket cylinder. And a recording medium transfer step of transferring a line image on the surface of the blanket to the recording medium by pressing and contacting the recording medium having a width wider than that of the printing plate to the blanket with an impression cylinder. In the blanket cylinder transfer process, the pressure applied to the blanket is recessed at the position of the blanket where the both edges of the printing plate face each other so that both edges of the printing plate are lower than those other than both edges of the printing plate. Provided is a lithographic printing method using a blanket cylinder provided with a portion, or a plate cylinder provided between the printing plate and the plate cylinder, and a plate cylinder provided in a range other than both end edges of the printing plate. That.

  A blanket for lithographic printing to which an image line image of ink formed on a printing plate mounted on the peripheral surface of a plate cylinder is transferred, and a dent is provided at a position where both end edges of the printing plate face each other. Provided blanket.

  According to the present invention, it is possible to prevent the ink attached to the edge of the printing plate from being printed on the recording medium.

  In the present invention, it is preferable that a plurality of printing plates are mounted on the plate cylinder. The present invention is particularly effective for printing a newspaper or the like in which a plurality of printing plates are mounted on a plate cylinder.

  In the present invention, the distance between the both end edges of the printing plate and the facing blanket is preferably 0.12 mm or more and 0.50 mm or less. In the present invention, the pressure applied to the blanket at both end edges of the printing plate may be lower than that other than the both end edges of the printing plate, but the distance between the both end edges and the blanket is 0.12 mm or more and 0.50 mm or less. If so, it is possible to more reliably prevent the ink attached to the edge of the printing plate from being printed on the recording medium.

  Here, the “distance between both edge of the printing plate and the blanket” is the depth of the concave portion before being pressed by the printing plate when the concave portion is provided in the blanket cylinder, and printing. When the plate is provided in a range other than the both end edges of the plate, there is a difference in height between the both end edges of the printing plate and the portions other than the both end edges of the printing plate.

  According to the planographic printing apparatus and planographic printing method according to the present invention, it is possible to provide a planographic printing apparatus and planographic printing method capable of preventing the ink adhering to the edge of the printing plate from being printed on the recording medium. it can.

1 is a perspective view schematically showing an entire lithographic printing apparatus. 1 is a cross-sectional view schematically showing a plate cylinder and a blanket cylinder according to the present invention. 1 is a cross-sectional view schematically showing a plate cylinder and a blanket cylinder according to the present invention. 1 is a cross-sectional view schematically showing a plate cylinder and a blanket cylinder according to the present invention. It is sectional drawing which shows schematically the plate cylinder and blanket cylinder which concern on the past.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a planographic printing apparatus and a planographic printing method according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram illustrating an example of a lithographic printing apparatus.

  A lithographic printing apparatus 10 in FIG. 1 is a lithographic printing apparatus that simultaneously prints both sides of a recording medium. The front side of the recording medium is printed with the upper side of the drawing, and the back side of the recording medium is printed with the lower side of the drawing.

  First, a configuration for printing on the surface of a recording medium will be described.

  A sheet-like or web-like recording medium (also referred to as “printing paper” or “paper”) 12 is sandwiched between an impression cylinder 36 and a blanket cylinder 16. The blanket cylinder 16 has a blanket 15 attached to the peripheral surface. The blanket cylinder 16 is in contact with the plate cylinder 18, and printing plates 19 a, 19 b, 19 c and 19 d are mounted on the plate cylinder 18.

  As shown in FIG. 1, in the printing of a newspaper by a lithographic printing plate, a double cylinder (this is also referred to as a full width) corresponding to the width of four newspaper pages is equipped with a plate cylinder 18 so that the width is equivalent to one newspaper page or two pages. Printing plates 19a, 19b, 19c and 19d having corresponding widths are mounted in parallel in the circumferential axis direction of the plurality of plate cylinders. Four printing plates 19 a, 19 b, 19 c and 19 d are wound around the peripheral surface of the plate cylinder, and all of the printing plates 19 a, 19 b, 19 c and 19 d are mounted in a state where both ends thereof are hooked and fixed in the recesses of the mounting portion 17. Here, the printing plates 19a, 19b, 19c, and 19d are mounted on adjacent printing plates at intervals of 3 to 15 mm, respectively.

  The four printing plates 19 a, 19 b, 19 c and 19 d equipped on the outer peripheral surface of the plate cylinder 18 are inked by a water / ink supply system using the dampening water supply means 20 and the ink supply means 22.

  1 is transferred onto the blanket 15 of the blanket cylinder 16, and the blanket image is formed on the printing plates 19a, 19b, 19c and 19d. The image line image of the ink transferred onto the image recording medium 15 is transferred to the recording medium 12 by pressurization by the impression cylinder 14, so that the image line image is printed on one surface of the recording medium 12.

  Next, a configuration for printing on the back surface of the recording medium will be described.

  The recording medium 12 is sandwiched between the impression cylinder 16 and the blanket cylinder 36. A blanket 35 is attached to the peripheral surface of the blanket cylinder 36. The blanket cylinder 36 is in contact with the plate cylinder 38, and printing plates 39a, 39b, 39c and 39d are mounted on the plate cylinder 38 (however, the printing plates 39a and 39b are not shown).

  As can be seen from the above, when printing on the surface of the recording medium, the blanket cylinder 36 functions as the impression cylinder 36, and when printing on the back surface of the recording medium, the blanket cylinder 16 serves as the impression cylinder 16. work.

  Four printing plates are respectively wound on the peripheral surface of the plate cylinder, and both of the printing plates are mounted in a state where both ends thereof are hooked and fixed in the recesses of the mounting portion 37.

  The four printing plates 39a, 39b, 39c and 39d provided on the outer peripheral surface of the plate cylinder 38 are inked by a water / ink supply system using the dampening water supply means 40 and the ink supply means 42.

  As described above, the image line image of the ink formed on the printing plates 39a, 39b, 39c and 39d is transferred onto the blanket 35 of the blanket cylinder 36 by the configuration on the lower side of the planographic printing apparatus 10 in FIG. The image line image of the ink transferred onto the blanket 35 is transferred to the recording medium 12 by pressurization by the impression cylinder 16, whereby the image line image is printed on the other surface of the recording medium 12.

  The lithographic printing apparatus 10 configured as described above prints a line image on both the front and back surfaces of the recording medium.

  As shown in FIG. 1, in a lithographic printing apparatus 10 that transfers an image line image of ink onto a recording medium 12 wider than the printing plate, the ink attached to the cutting edge (edge) of the printing plate is printed on the paper surface. There was a problem of becoming dirty and detracting from the commercial value of the printed matter.

  Therefore, in the present embodiment, (1) the position of the blanket where both end edges of the printing plate face each other so that the pressure applied to the blanket is lower at both end edges of the printing plate than at both ends of the printing plate. Or (2) a plate is provided between the printing plate and the plate cylinder in a range other than the both edges of the printing plate.

  FIG. 2 is a cross-sectional view schematically showing an example of a plate cylinder and a blanket cylinder according to the present embodiment.

  2 and 3 show an example in which a recessed portion is provided at the position of the blanket where both end edges of the printing plate (1) are opposed to each other. FIG. 4 shows an example in which a plate is provided in a range other than the both edges of the printing plate between the printing plate and the plate cylinder of (2) above.

  In addition, although the code | symbol of a printing plate or a blanket cylinder has attached | subjected only the code | symbol of the structure of the upper side of the lithographic printing apparatus 10 of FIG. 1, it is similarly formed in the structure of the lower side of the lithographic printing apparatus 10 of FIG.

  Conventionally, any one of FIGS. 5A, 5B, 5C, and 5D is configured, and the ink attached to the edges 26 of the printing plates 19a, 19b, 19c, and 19d is blanket. Since it is transferred to the blanket 15 of the cylinder 16, it is printed on the recording medium 12.

  In FIG. 5B, an under blanket 15A for adjusting the printing pressure is further provided under the blanket 15 in FIG. In FIG. 5C, a plate lower 18 </ b> A is further provided between the printing plates 19 a, 19 b, 19 c and 19 d of FIG. 5A and the plate cylinder 18. In FIG. 5D, an under blanket 15A and a block 18A are further provided in FIG.

  FIG. 2A shows a blanket in which the under blanket 15A near the edge 26 of the printing plates 19a, 19b, 19c and 19d is removed from the conventional blanket cylinder 16 of FIG. The recessed portion 30 is provided at the position. 2B is a blanket in which an additional under blanket 15B is provided on the under blanket 15A of FIG. 5B in a range other than the vicinity of the edge of the printing plate, and both edges of the printing plate face each other. The recessed portion 30 is provided at the position. The depth X of the dent before being pressed by the printing plate is preferably 0.12 to 0.50 mm, and more preferably 0.15 to 0.30 mm. If it is smaller than 0.12 mm, ink transfer from the edge to the blanket is not sufficiently suppressed. Moreover, when larger than 0.50 mm, it leads to the strength fall of a blanket and is unpreferable.

  By configuring the blanket cylinder 16 in this way, the pressure applied to the blanket can be such that both end edges of the printing plate are lower than those other than both end edges of the printing plate. This prevents the ink adhering to the edge of the printing plate from being transferred to the blanket of the blanket cylinder, thereby preventing the ink adhering to the edge of the printing plate from being printed on the recording medium 12. .

  FIG. 3 shows a conventional blanket cylinder 16 shown in FIG. 5A in which a recessed portion 30 is provided at a position where both edges of the printing plate face the blanket 15. The depth Y of the dent before being pressed by the printing plate is preferably 0.12 to 0.50 mm, and more preferably 0.15 to 0.30 mm. If it is smaller than 0.12 mm, ink transfer from the edge to the blanket is not sufficiently suppressed. Moreover, when larger than 0.50 mm, it leads to the strength fall of a blanket and is unpreferable.

  By configuring the blanket cylinder 16 in this way, the pressure applied to the blanket can be such that both end edges of the printing plate are lower than those other than both end edges of the printing plate. This prevents the ink adhering to the edge of the printing plate from being transferred to the blanket of the blanket cylinder, thereby preventing the ink adhering to the edge of the printing plate from being printed on the recording medium 12. . In the embodiment of FIG. 2B, an under blanket 15A may be provided under the blanket 15 on the entire surface.

  FIG. 4A shows a plate between the printing plates 19a, 19b, 19c and 19d and the plate cylinder 18 shown in FIG. 5A and in a range other than the edges of the printing plates 19a, 19b, 19c and 19d. A lower 18B is provided. Thus, by providing the lower plate 18 </ b> B, the pressure applied to the blanket can be such that both end edges of the printing plate are lower than those other than both end edges of the printing plate. Accordingly, it is possible to prevent the ink attached to the edge of the printing plate from being transferred to the blanket of the blanket cylinder, thereby preventing the ink attached to the edge of the printing plate from being printed on the recording medium 12. be able to. Further, as shown in FIG. 4B, an additional template 18A may be provided on the template 18A that exists in advance on the entire surface, in a range other than the edges of the printing plates 19a, 19b, 19c, and 19d. Good. The height difference Z between the both end edges of the printing plate and the portions other than the both end edges of the printing plate is preferably 0.12 to 0.50 mm, and more preferably 0.15 to 0.30 mm.

  In the present embodiment, the printing plate of FIG. 2 or FIG. 3 is provided with a concave portion at the position of the blanket where both end edges of the printing plate face each other, and the plate is provided in a range other than the both ends of the printing plate of FIG. You may combine things.

  That is, in the present embodiment, the distance (gap 32) between the opposite edge of the printing plate and the blanket facing the printing plate is more preferably 0.12 to 0.50 mm, and further preferably 0.15 to 0.30 mm. When it is smaller than 0.12 mm, ink transfer from the edge to the blanket is not sufficiently suppressed. On the other hand, when the thickness is larger than 0.50 mm, it is not preferable because it leads to deterioration of durability such that the blanket is easily cracked or torn due to the deformation of the blanket.

  The blanket 15 may be a single layer or multiple layers, but an oil-resistant polymer is used for the surface layer in consideration of printing ink, ink washing solvent, and the like. As the oil-resistant polymer, for example, one or more vulcanizing agents such as sulfur, a vulcanization accelerator, and an anti-aging agent are added to an oil-resistant rubber such as chloroprene rubber, nitrile rubber, and acrylic rubber.

  In the planographic printing apparatus 10 of FIG. 1, when newspaper printing is performed as an example, the paper width is 1626 mm, the printing plate width is 390 to 410 mm or 790 to 810 mm, and the interval between adjacent printing plates is 3 to 15 mm. The edge width of both end edges that make the pressure to be applied lower than the edges other than the both end edges of the printing plate is 2 to 10 mm. The width of the printing plate is 390 to 410 mm when printing one newspaper page (half-page spread) with one printing plate, and printing one page (two newspaper pages) with one printing plate. Is 790 to 810 mm.

  In the above-described embodiment, an example in which four printing plates are provided on the peripheral surface of the plate cylinder is described as an example. However, the printing plate may be one or a plurality of other than four. This embodiment is effective when printing on printing paper larger than the width of the printing plate.

  DESCRIPTION OF SYMBOLS 10 ... Lithographic printing apparatus, 12 ... Recording medium, 15 ... Blanket, 15A, 15B ... Under blanket, 16 ... Blanket cylinder (impression cylinder), 18 ... Plate cylinder, 18A, 18B ... Block, 19a, 19b, 19c, 19d: printing plate, 20: dampening water supply means, 22 ... ink supply means, 26 ... edge, 30 ... recessed portion, 32 ... gap, 35 ... blanket, 36 ... impression cylinder (blanket cylinder), 38 ... plate cylinder, 39a, 39b, 39c, 39d ... printing plate, 40 ... dampening water supply means, 42 ... ink supply means

Claims (8)

A plate cylinder on which a printing plate is mounted on the peripheral surface;
A blanket cylinder having a blanket to which an image line image of the ink formed on the printing plate is transferred;
An impression cylinder that is disposed at a position facing the blanket cylinder and pressurizes a recording medium having a width wider than the printing plate onto which a line image on the blanket is transferred;
The pressure applied to the blanket is such that both end edges of the printing plate in the circumferential axis direction of the plate cylinder are lower than those of both ends of the printing plate in the circumferential axis direction of the plate cylinder , A concave portion is provided at the position of the blanket where both end edges of the printing plate face each other in the circumferential axis direction of the plate cylinder , or the circumferential axis of the plate cylinder between the printing plate and the plate cylinder A lithographic printing apparatus in which a plate is provided in a range other than both edges of the printing plate in the direction .   The lithographic printing apparatus according to claim 1, wherein a plurality of the printing plates are mounted on the plate cylinder.   The lithographic printing apparatus according to claim 1 or 2, wherein a distance between the both end edges of the printing plate and the blanket facing the printing plate is 0.12 mm or more and 0.50 mm or less. A blanket cylinder transfer step of transferring an image line image of the ink formed on the printing plate mounted on the peripheral surface of the plate cylinder to the surface of the blanket attached to the blanket cylinder;
A recording medium transfer step of transferring the image line image on the surface of the blanket to the recording medium by pressing and contacting the blanket with the impression cylinder by a pressure cylinder having a width wider than the printing plate; Have
Wherein the blanket cylinder transfer step, the pressure pressed against the blanket, both ends of the plate cylinder the printing plate in the peripheral surface axial direction of the plate cylinder from the other end edges of the printing plate in the peripheral surface axial direction of A blanket cylinder provided with a recessed portion at a position of the blanket where both edges of the printing plate face each other in the circumferential axis direction of the plate cylinder so that the edge is lowered, or the printing plate and the plate cylinder A lithographic printing method using a printing cylinder provided with a printing plate in a range other than both end edges of the printing plate in the circumferential axis direction of the printing drum.   The lithographic printing method according to claim 4, wherein a plurality of the printing plates are mounted on the plate cylinder.   The lithographic printing method according to claim 4 or 5, wherein a distance between the both end edges of the printing plate and the blanket facing the printing plate is 0.12 mm or more and 0.50 mm or less. A blanket for lithographic printing to which an image line image of ink formed on a printing plate mounted on a peripheral surface of a plate cylinder is transferred,
A blanket provided with recessed portions at positions where both end edges of the printing plate face each other in the circumferential axis direction of the plate cylinder .   The blanket according to claim 7, wherein a depth of the recessed portion is 0.12 mm or more and 0.50 mm or less.

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