JP2008230194A - Manufacturing method of letterpress and offset printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a letterpress manufacturing method and an offset printing device equipped with the letterpress that can efficiently form the letterpress to be mounted onto the periphery of the plate cylinder and can prevent the occurrence of poor printing by inhibiting the accumulation of an ink onto the periphery of the plate cylinder. <P>SOLUTION: This invention refers to the manufacturing process of the letterpress that is mounted on the plate cylinder 15 and that is to be used in the offset printing device having the plate cylinder 15, the supply roll which supplies an ink to the plate cylinder 15 and the blanket cylinder with the blanket mounted. The letterpress 15b has a transfer section 15d which is in contact with the blanket and the non-transfer section which is not in contact with the blanket. The raised section 15h is formed protruding radially outward from the periphery of the plate cylinder 15, and the transfer section is formed by the laser process on the portion positioned radially outward in the plate cylinder 15 by the raised section 15h among the plate members mounted on the periphery of the plate cylinder 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a method of manufacturing a relief plate used in an offset printing apparatus including a plate cylinder, a supply roll for supplying ink to the plate cylinder, and a blanket cylinder having a blanket disposed on the outer peripheral surface, and the relief plate. The present invention relates to an offset printing apparatus.

A two-piece can used as a container for soft drinks, etc. consists of a can lid and a cylindrical can body, and the can body is printed on the outer surface after DI (deep drawing, ironing) processing and washing. Is given. In printing the can body, an offset printing apparatus as shown in Patent Document 1 and Patent Document 2 is used.
In such an offset printing apparatus, a plate cylinder having a cylindrical outer shape and a printing plate such as a relief plate disposed on the outer peripheral surface, and a rubber blanket slidably contacting the outer peripheral surface of the plate cylinder are provided on the outer peripheral surface. A blanket cylinder disposed on the printing plate, ink is applied to the printing plate, the ink is transferred to the blanket, and the blanket is slidably contacted with the outer circumferential surface of the can cylinder to Printing is performed.

Further, in Patent Document 2, by inserting an underlay between the blanket cylinder and the blanket, the rotation direction edge of the blanket contacts the surface of the printing plate and the surface of the printing plate is damaged. And the contact between the printing plate and the portion of the outer peripheral surface of the blanket cylinder where the blanket is not provided (hereinafter referred to as “non-blanket portion”) prevents the ink on the printing plate from What prevents the occurrence of so-called soiling that adheres is disclosed.
JP 2006-181727 A Japanese Patent No. 3675500

By the way, the relief plate disposed on the outer peripheral surface of the plate cylinder as a printing plate is provided with a transfer portion that contacts the blanket and transfers ink and a non-transfer portion that is not in contact with the blanket.
Here, in the conventional method for producing a relief printing plate, an image is formed on the transfer portion and not in contact with the blanket, that is, the non-transfer portion is positioned radially inward of the plate cylinder from the transfer portion. It was necessary to process.

  Further, in the offset printing method described in Patent Document 2, although the non-blanket portion and the relief printing plate are not in contact with each other, the outer peripheral surface of the plate cylinder is always in contact with the ink supply roll. Of this, the ink that has adhered to the part where the relief printing plate is not arranged or the non-transfer area of the relief printing plate accumulates, and this ink adheres to the blanket due to the centrifugal force when the plate cylinder rotates, resulting in poor printing on the outer peripheral surface of the cylindrical article. There was a risk of generating.

  The present invention has been made in view of the above-described circumstances, and can efficiently form a relief plate disposed on the outer peripheral surface of the plate cylinder, preventing accumulation of ink on the outer peripheral surface of the plate cylinder. It is an object of the present invention to provide a method for manufacturing a relief printing plate capable of suppressing the occurrence of printing defects and an offset printing apparatus provided with the relief printing plate.

  In order to solve the above-described problems, a method for producing a relief printing plate according to the present invention includes a plate cylinder having a cylindrical shape, a supply roll for supplying ink to the outer peripheral surface of the plate cylinder, and ink supplied to the plate cylinder. Is used in an offset printing apparatus provided with a blanket to which the blanket is transferred and a blanket cylinder provided on the outer peripheral surface, and a method for producing a relief plate provided on the outer peripheral surface of the plate cylinder, The relief printing plate includes a transfer portion that contacts the blanket and transfers an image, and a non-transfer portion that is not in contact with the blanket. A part of the plate cylinder in the circumferential direction has a diameter in the circumferential direction. A raised portion protruding outward in the direction is formed, and a plate material is disposed on the outer peripheral surface of the plate cylinder. The serial was is positioned radially outward of the plate cylinder section is characterized by forming the transfer portion by laser processing.

  According to the method of manufacturing a relief printing plate having this configuration, the plate material is disposed on the outer peripheral surface of the plate cylinder, and the plate cylinder is radially outside by the raised portion formed on the outer peripheral surface of the plate cylinder of the plate material. Since the transfer portion is formed by laser processing in the portion positioned in the direction, the non-transfer portion is disposed so as to recede inward in the radial direction from the transfer portion and does not come into contact with the blanket. Therefore, it is not necessary to process the non-transfer portion by laser processing, and the relief can be formed efficiently.

  The offset printing apparatus according to the present invention includes a supply roll for supplying ink to the outer peripheral surface of the plate cylinder, a blanket for transferring the ink supplied to the plate cylinder, and the blanket disposed on the outer peripheral surface. An offset printing apparatus provided with a blanket cylinder, wherein the relief printing plate includes a transfer part that contacts the blanket and transfers an image, and a non-transfer part that is not in contact with the blanket, On the outer peripheral surface of the plate cylinder, a raised portion in which a part in the circumferential direction protrudes radially outward is formed, and a portion of the relief plate where the transfer portion is formed is located outside the raised portion. The transfer portion is positioned more radially outward of the plate cylinder than the non-transfer portion.

  According to the offset printing apparatus having this configuration, the non-transfer portion provided in the relief plate is retreated inward in the radial direction of the plate cylinder, so that it is not in contact with the ink supply roll, and ink adheres to the non-transfer portion. Can be prevented. Further, since the non-transfer portion of the relief printing plate and the surface of the blanket are not in contact with each other, for example, when printing, even if ink adheres to the non-transfer portion due to ink dripping on the transfer portion on the surface of the relief printing plate. Ink can be prevented from adhering to the surface of the blanket. This makes it possible to limit the ink transferred to the outer peripheral surface of the cylindrical article to the ink transferred from the transfer portion to the surface of the blanket due to the contact between the relief transfer portion and the blanket, resulting in poor printing. Can be prevented.

Here, the raised portion may be formed by inserting a spacer between the plate cylinder and the plate material.
In this case, by inserting a spacer between the plate cylinder and the plate material arranged on the outer peripheral side of the plate cylinder, a part of the plate material can be surely positioned radially outward and raised. The circumferential position of the part can be set with high accuracy. The spacer is preferably made of a material having a lower hardness than the plate material.

  According to the present invention, it is possible to efficiently form a relief plate disposed on the outer peripheral surface of the plate cylinder, and to prevent the occurrence of printing defects by preventing the accumulation of ink on the outer peripheral surface of the plate cylinder. And an offset printing apparatus provided with the relief printing plate.

Embodiments of the present invention will be described below with reference to the accompanying drawings. An outline of an offset printing apparatus according to this embodiment is shown in FIG.
1 and 2 show a schematic configuration of an offset printing apparatus 10 shown as the first embodiment of the present invention, which includes an ink adhesion mechanism 11, a can moving mechanism 21, and an overcoat processing mechanism 31. FIG. ing.

  The ink adhering mechanism 11 is provided on the outer peripheral surface of the DI can 50 (cylindrical article) on which the size coat film is formed on the inker units 11a to 11f provided for each ink color, and the ink transferred from each of the inker units 11a to 11f. And a blanket cylinder 12 provided with a plurality of blankets 12a to be transferred.

  The inker units 11 a to 11 f include an ink source 13, a roll unit 14, and a plate cylinder 15 having an outer peripheral surface provided with a relief plate 15 b. The roll unit 14 includes a ducting roll 14a to which ink is supplied from the ink source 13, a supply roll 14c that is formed of an elastic material such as rubber and supplies ink to the relief plate 15b, and the ducting roll 14a to the supply roll 14c. And an intermediate roll 14b for delivering ink.

  The blanket cylinder 12, the plate cylinder 15 and the supply roll 14c extend so that their respective axes are parallel to each other, and the outer peripheral surface of the plate cylinder 15 is the outer peripheral surface of the blanket cylinder 12 and the outer peripheral surface of the supply roll 14c. It is arrange | positioned so that it may be pinched | interposed by. Further, in the blanket cylinder 12 and the plate cylinder 15, the relief plate 15 b is in contact with the surface of the blanket 12 a and the blanket cylinder 12 is not provided with the blanket 12 a (hereinafter referred to as “non-blanket part”). It is supported so as to be rotatable around each axis so as to be in non-contact with 12b.

The can moving mechanism 21 includes a can shooter 22 for taking in the DI can 50, a mandrel 23 for rotatably holding the DI can 50 supplied from the can shooter 22, and the DI can 50 attached to the mandrel 23 in the order of installation. And a mandrel turret 24 that sequentially rotates toward the attachment mechanism 11.
The overcoat processing mechanism 31 includes a roll coater 32 that applies an overcoat paint on the outer peripheral surface of the DI can 50 to which the ink pattern is transferred from the blanket 12a.

  Here, in this embodiment, as shown in FIGS. 2 and 3, the transfer portion 15d of the relief plate 15b is connected to the edge of the transfer portion 15d between the plate cylinder 15 and the relief plate 15b. A spacer 15c is inserted so as to be positioned radially outward of the plate cylinder 15b with respect to the non-transfer portion 15a constituting the outer edge portion. The spacer 15c is made of a resin material having a hardness lower than that of the relief plate 15b (for example, a hardness of 30 degrees to 70 degrees). The raised portion 15 h is formed on the outer peripheral surface of the plate cylinder 15 by the spacer 15 c.

  Further, the spacer 15c has a larger area than the transfer portion 15d of the relief plate 15b and is located outside the transfer portion 15d and the outer peripheral edge of the transfer portion 15d, and contributes to the pattern although laser processing is performed. The area of the spacer 15c is smaller than the outer peripheral end of the transfer unit 15d and the inner side of the outer peripheral end of the laser processing unit 15e or an equivalent position. The entire surface of the spacer 15c is covered with the relief plate 15b so as to be positioned at the position. The spacer 15c has a thickness of about 0.2 mm to 1.0 mm, and is equal to or greater than the thickness of the relief plate 15b. Furthermore, in the present embodiment, a portion of the outer peripheral surface of the plate cylinder 15 excluding a position corresponding to the transfer portion 15d is subjected to a polishing process of about 0.5 mm to 1.0 mm.

  From the above, as shown in FIG. 2, when printing a pattern on the outer peripheral surface of the DI can 50, only the transfer portion 15d of the relief plate 15b contacts the surface of the blanket 12a and the outer peripheral surface of the supply roll 14c (see FIG. 2 (a)), the non-transfer portion 15a is not in contact with the surface of the blanket 12a and the outer peripheral surface of the supply roll 14c (see FIG. 2 (b)).

Next, a method for manufacturing the relief plate 15b will be described. A plate material is attached to the outer peripheral surface of the plate cylinder 15, a spacer 15 c is inserted between the plate material and the outer peripheral surface of the plate cylinder 15, and a part of the plate material is positioned radially outward of the plate cylinder 15. Then, a transfer portion 15d is formed by laser processing on the surface of the plate material positioned radially outward by the spacer 15c (the raised portion 15h). As shown in FIG. 3, the transfer portion 15d includes a base portion 15f that is recessed radially inward from the surface of the plate material, and a projection portion 15g that protrudes radially outward from the base portion 15f. The ink attached to the top of the protrusion 15g is transferred to the blanket 12a.
Here, the laser processing conditions are preferably a CO2 laser, for example, at a wavelength of 2.5 to 11 [mu] m and an output of 100 to 500 W. In this embodiment, the wavelength is 10.6 [mu] m and the output is 200 W, and the rotation speed of the plate material Was set to 520 rpm.

The offset printing apparatus 10 having such a configuration performs printing on the outer peripheral surface of the DI can 50 as follows.
First, in each inker unit 11a to 11f, ink of each color is applied from the ink source 13 to the transfer portion 15d of the relief plate 15b of the plate cylinder 15 via the roll unit 14, and then, from the transfer portion 15d of each relief plate 15b to the blanket cylinder. The ink of each color is transferred as a pattern onto the surface of each blanket 12a provided on 12, so that a pattern or the like printed on the outer peripheral surface of the DI can 50 is formed on the surface of the blanket 12a.

  On the other hand, the DI can 50 on which the size coat film is formed is transferred from the can shooter 22 to the mandrel 23 and is rotatably supported by the mandrel 23, and then the outer peripheral surface of the DI can 50 is transferred with the ink. The design and the like are printed by being pressed against the surface of the blanket 12a by a mandrel turret 24.

  Next, the DI can 50 is transferred to the overcoat processing mechanism 13, and the overcoat paint is applied to the entire outer peripheral surface of the printed DI can 50 by the roll coater 32. And an outer surface coating film is formed by baking and drying this.

  According to the offset printing apparatus 10 of the present embodiment, when printing a pattern on the outer peripheral surface of the DI can 50, the non-transfer portion 15a of the relief plate 15b and the outer peripheral surface of the supply roll 14c are not in contact with each other. It is possible to suppress the ink on the supply roll 14c from adhering to the non-transfer portion 15a.

Further, since the non-transfer portion 15a of the relief plate 15b and the surface of the blanket 12a are not in contact with each other, for example, during the printing, ink adheres to the non-transfer portion 15a due to dripping of ink on the transfer portion 15d on the surface of the relief plate 15b. Even so, this ink can be prevented from adhering to the surface of the blanket 12a.
From the above, it is possible to limit the ink transferred to the outer peripheral surface of the DI can 50 to the ink transferred from the transfer portion 15d to the surface of the blanket 12a by the contact between the transfer portion 15d of the relief printing plate 15b and the blanket 12a. Thus, it is possible to prevent printing defects from occurring.

  Further, the relief plate 15b disposed on the outer peripheral surface of the plate cylinder 15 is formed by performing laser processing on the surface of the plate material positioned radially outward by the spacer 15c (raised portion 15h). Therefore, the non-transfer portion 15 a moves backward inward in the radial direction of the plate cylinder 15. Therefore, it is not necessary to process the non-transfer portion 15a, and the relief plate 15b can be formed efficiently.

Next, an offset printing apparatus according to the second embodiment of the present invention will be described. FIG. 4 shows an outline of the relief plate 25b and the plate cylinder 25 used in the offset printing apparatus according to the second embodiment of the present invention.
In the plate cylinder 25, a raised portion 25h is formed integrally with the plate cylinder 25. That is, a part of the outer circumferential surface of the plate cylinder 25 is configured to protrude radially outward.
Further, the relief plate 25 b has a substantially cylindrical shape and is disposed on the outer peripheral side of the plate cylinder 25. That is, the plate cylinder 25 is fitted on the inner peripheral side of the relief plate 25b.

  In the offset printing apparatus having this configuration, since the raised portion 25h is formed integrally with the plate cylinder 25, the circumferential direction position of the plate cylinder 25 of the raised portion 25h does not change, and the outer peripheral side of the plate cylinder 25 It is possible to reliably project a part of the relief plate 25b disposed on the outer side in the radial direction.

Although the embodiment of the present invention has been described above, the technical scope of the present invention is not limited to this embodiment, and various modifications can be made without departing from the spirit of the present invention. .
For example, in the above-described embodiment, the DI can 50 is shown as a cylindrical article. However, the present invention can be applied to a case where a pattern is printed on the outer peripheral surface of a cylindrical article other than the DI can 50.
In the above-described embodiment, the offset printing apparatus 10 includes the can moving mechanism 21 and the overcoat processing mechanism 31. However, at least the blanket cylinder 12, the blanket 12a, the plate cylinder 15, and the relief plate of the ink adhesion mechanism 11 are shown. If it has 15b, the raising part, and the supply roll 14c, it will not be restricted to the said embodiment.

The laser processing conditions are not limited to the present embodiment, and are preferably set as appropriate in consideration of the material of the plate material, the pattern shape of the transfer portion to be formed, and the like.
Furthermore, a cylindrical sleeve is attached to the outer peripheral surface of the plate cylinder, a plate material is disposed on the outer peripheral surface of the sleeve, and a spacer is inserted between the plate cylinder and the sleeve, or between the sleeve and the plate material. The material may be laser processed.

It is a schematic diagram of the offset printing apparatus which is the 1st Embodiment of this invention. It is an enlarged view of the plate cylinder, blanket, and supply roll with which the offset printing apparatus shown in FIG. 1 was equipped. FIG. 2 is an enlarged cross-sectional view of a relief plate disposed on an outer peripheral surface of a plate cylinder provided in the offset printing apparatus shown in FIG. 1. It is an enlarged view of the plate cylinder, blanket, and supply roll with which the offset printing apparatus which is the 2nd Embodiment of this invention was equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Offset printing apparatus 12 Blanket cylinder 12a Blanket 14c Supply roll 15, 25 Plate cylinder 15a, 25a Non-transfer part 15b, 25b Letterpress 15c Spacer 15d, 25d Transfer part

Claims (4)

A cylindrical plate cylinder, a supply roll for supplying ink to the outer peripheral surface of the plate cylinder, a blanket to which the ink supplied to the plate cylinder is transferred, and a blanket cylinder provided with the blanket on the outer peripheral surface A method of manufacturing a relief plate disposed on the outer peripheral surface of the plate cylinder,
The relief printing plate includes a transfer part that contacts the blanket and transfers an image, and a non-transfer part that is not in contact with the blanket.
On the outer peripheral surface of the plate cylinder, a raised portion in which a part of the circumferential direction protrudes radially outward is formed,
A plate material is disposed on an outer peripheral surface of the plate cylinder, and the transfer portion is formed by laser processing on a portion of the plate material that is positioned radially outward of the plate cylinder by the raised portion. A method for producing a relief printing.   The method for producing a relief printing plate according to claim 1, wherein the raised portion is formed by inserting a spacer between the plate cylinder and the plate material. An offset printing apparatus comprising a supply roll for supplying ink to the outer peripheral surface of the plate cylinder, a blanket to which the ink supplied to the plate cylinder is transferred, and a blanket cylinder having the blanket disposed on the outer peripheral surface. There,
The relief printing plate includes a transfer part that contacts the blanket and transfers an image, and a non-transfer part that is not in contact with the blanket.
On the outer peripheral surface of the plate cylinder, a raised portion in which a part of the circumferential direction protrudes radially outward is formed,
A portion of the relief plate where the transfer portion is formed is disposed so as to be positioned outside the raised portion, and the transfer portion is positioned radially outward of the plate cylinder relative to the non-transfer portion. An offset printing apparatus characterized by that.   The offset printing apparatus according to claim 3, wherein the raised portion is formed by a spacer inserted between the plate cylinder and the plate material.

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