JP2008110521A - Offset printing method and offset printing press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contrive to solve the problem that ink left in a printing plate mounting groove is transferred to a blanket surface and further to a web resulting in remarkably marring printing quality. <P>SOLUTION: The solution of the problematic point depends upon a newspaper offset printing method by which printing is performed by rotating two blanket cylinders in opposite directions under the phase relationship that the blanket mounting groove of one blanket cylinder is shifted in its rotational direction by the peripheral length corresponding to the printing pitch printed by a printing plate 1 under the condition that the blanket mounting groove of the other blanket cylinder occupies a position at which the web is clamped, and a newspaper offset printing press in which the blanket mounting grooves of two adjacent blanket cylinders are provided so that the peripheral length of the blanket lying between the blanket mounting grooves is provided two times as long as the printing pitch printed by the printing plate 1 and, in addition, the blanket mounting grooves of the two adjacent blanket cylinders are provided at a position shifted in its rotational direction by the peripheral length corresponding to the printing pitch printed by the printing plate 1 from the position at which the web is clamped by the two blanket cylinders. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a newspaper offset printing method and a newspaper for printing with a continuous paper sandwiched between two blanket cylinders to which a blanket having a length in the circumferential direction twice the printing pitch printed by one printing plate is attached. The present invention relates to an offset printing machine.

  For example, “Off-wheel printing technology (GATF Kyokuto Office, Satoshi Fukuhara, first published on September 15, 1986) is a technology that prints through a blanket surface with a continuous paper sandwiched between two blanket cylinders with a blanket attached. Pp. 11 to 20 are described as "BB type off-wheel printing unit" (Non-patent Document 1: Prior Art 1).

  In Non-Patent Document 1, both the printing plate mounting groove of the plate cylinder and the blanket mounting groove of the blanket cylinder are described by the word “gap”, and the width of the “gap” is the same as that of Non-Patent Document 1. As shown in the 15th line to the 9th line from the bottom of the right column on page 12 and FIG. 12, the blanket mounting groove is formed to be slightly wider than the plate mounting groove of the plate cylinder.

  In addition, in a newspaper offset printing press, there is a description of a plate cylinder in the first column, lines 12 to 26 of US Pat. No. 6,408,747 (Patent Document 1: Prior Art 2). In general, the plate cylinder is 1 page circumference x 2 pages wide, 2 pages circumference x 2 pages wide, 2 pages circumference x 4 pages wide, and a blanket cylinder is also 1 page. Peripheral length × 2 page width, 2 page peripheral length × 2 page width, 2 page peripheral length × 4 page width. Further, Patent Document 1 also discloses a configuration in which a plate cylinder of 1 page circumference x 4 pages width and a blanket cylinder of 2 pages circumference x 4 pages width are combined.

  Each of the printing plate mounting groove of the plate cylinder and the blanket mounting groove of the blanket cylinder is provided in a central axis direction at one location on the peripheral surface in a cross section perpendicular to the central axis of each cylinder. For a cylinder with a long center axis, for example, a 4-page width plate cylinder or a blanket cylinder of a newspaper offset printing press, the position where the plate mounting groove and the blanket mounting groove corresponding to the 2-page width are provided is the center in the direction of the center axis. The left and right sides of the printing plate or the blanket are arranged so as to be shifted from each other in the circumferential direction, and both ends of the printing plate or the blanket that substantially circulates the respective circumferential surfaces are fixed to the printing plate mounting groove and the blanket mounting groove, respectively. .

Japanese Patent Publication No. 2541549 (Patent Document 2: Conventional Technology 3) describes a technique of printing via a blanket surface with a continuous paper sandwiched between two adjacent blanket cylinders. In Patent Document 2, each blanket mounting groove (a cylinder groove in Patent Document 2) provided in two adjacent blanket cylinders (rubber cylinders in Patent Document 2) is opposed to each other at a position sandwiching the paper of the blanket cylinder. The rotational phase is determined so that
US Pat. No. 6,408,747 (prior art 2) Japanese Patent No. 2541549 (Prior Art 3) "Off-wheel printing technology" GATF Far East office, written by Kei Fukuhara, first published on September 15, 1981 (Prior art 1)

  In recent offset printing, especially newspaper printing, the content of articles has been changed by distribution area, and the content of news has changed over time. As described in Technology 2, the idea has come to be that running costs can be reduced by using a one-page printing plate. For example, a plate cylinder with a length of 2 pages is also provided with two plate mounting grooves at two halves on the circumferential surface in a cross section perpendicular to the axis, and two 1 page length printing plates are mounted in the circumferential direction for printing. There is a need for a printing machine that can change the printing plate for each page length when the collect operation is performed or the printing plate is damaged for some reason.

  By the way, in the offset printing, since the nip pressure is applied to the printing plate attached to the plate cylinder during the printing operation of the ink supply device, the ink form roller 5 is provided with the printing plate attachment groove portion 10 as shown in FIG. The plate falls along the trailing attachment end 102 of the printing plate in the rotation direction of the plate cylinder, and then abruptly rides on the preceding attachment end 101 of the printing plate in the rotation direction of the plate cylinder. At this time, useless ink may remain on the leading attachment end 101 and the trailing attachment end 102.

  For this reason, in an offset printing machine in which printing plates are provided at two halves on the circumferential surface of a two-page circumferential plate, and two printing plates of one page length are installed in the circumferential direction to enable printing. When one of the plate mounting grooves rotates opposite to the center in the circumferential direction of the 2-page long blanket surface, the unwanted residual ink is transferred to the blanket surface, and the blanket surface to which this unwanted residual ink has been transferred is adjacent. When the continuous paper is sandwiched with the blanket cylinder, the unnecessary ink is transferred to the continuous paper by the printing pressure acting between the blanket surfaces of the adjacent blanket cylinders, and the print quality is significantly impaired. It was.

In order to solve the above-mentioned problem, a newspaper offset printing method for printing by sandwiching continuous paper between two blanket cylinders to which a blanket having a length in the circumferential direction twice the printing pitch printed by one printing plate is attached. In
When the blanket mounting groove of one blanket cylinder is in a position to sandwich continuous paper, the blanket mounting groove of the other blanket cylinder is shifted in the rotational direction by the length in the circumferential direction corresponding to the printing pitch printed by one printing plate. A newspaper offset printing method is proposed in which printing is performed by rotating two blanket cylinders in opposite directions with a phase relationship at a certain position.

In addition, two blanket cylinders that are wound around the circumferential surface so that both ends of the blanket can be fixed by the blanket mounting groove are adjacent to each other, and a plate cylinder that is wound around the circumferential surface so that both ends of the printing plate can be fixed by the printing plate mounting groove In a newspaper offset printing machine that is arranged adjacent to two blanket cylinders and prints with continuous paper sandwiched between adjacent blanket cylinders,
The blanket mounting grooves of the two blanket cylinders adjacent to each other are provided so that the length of the blanket attached to each blanket is twice the printing pitch on which a printing plate with one printing plate is printed,
An offset printing press for newspapers, characterized in that two blanket cylinders are provided at positions shifted in the rotational direction by a length in the circumferential direction corresponding to the printing pitch on which one printing plate prints relative to the position where the continuous paper is sandwiched. Propose.

  According to this invention, the printing plate mounting grooves are provided at two halves on the circumferential surface of the two-page circumferential plate cylinder, and two printing plates of one page length can be mounted in the circumferential direction to enable printing. In the offset printing machine, when one printing plate mounting groove rotates opposite to the center in the circumferential direction of the two-page long blanket surface, unnecessary residual ink is transferred to the blanket surface in the same manner as in the background art. is there. However, when the blanket surface to which the residual ink is transferred reaches the position where the continuous paper is sandwiched with the adjacent blanket cylinder, the blanket surface is opposed to the blanket mounting groove of the adjacent blanket cylinder across the continuous paper. The printing pressure acting on the continuous paper is lost or significantly reduced by the relief of the blanket mounting groove. Therefore, the useless ink is not transferred to the continuous paper, or becomes extremely small to the extent that it cannot be visually observed, and it is possible to prevent the print quality from being impaired.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a newspaper offset printing machine according to an embodiment of the present invention. A newspaper cylinder 2 and 2 'in width, and blanket cylinders 2 and 2' having the same circumference and width. It is front explanatory drawing.

  The plate cylinders 1 and 1 'are respectively provided with plate mounting grooves 10a, 10b and 10a', 10b 'in parallel with the axis at two halves in the circumferential direction of the circumferential surface. Then, the printing plates 11a, 11b and 11a ', 11b' are mounted by a printing plate mounting device (not shown) provided in the printing plate mounting grooves 10a, 10b and 10a ', 10b'. The printing plates 11a, 11b and 11a ', 11b' attached to the plate cylinders 1 and 1 'are supplied with ink by a plurality of ink form rollers (not shown).

  The blanket cylinders 2 and 2 'are respectively provided with blanket mounting grooves 20 and 20' parallel to the axis at one place on the peripheral surface. Blankets 21 and 21 'are attached by a blanket mounting device (not shown) provided in the blanket attachment grooves 20 and 20'. A continuous paper W1 to be printed is sandwiched between the blanket cylinders 2 and 2 'so as to run in the direction of the arrow.

  Next, the circumferences of the plate cylinders 1 and 1 'and the blanket cylinders 2 and 2' are configured to be equal and the rotational speed is also synchronized. The phase relationship between the parts of each cylinder will be described. Of the printing plate mounting grooves 10a, 10b and 10a ', 10b', the printing plate mounting groove 10a is in a rotational phase relationship facing each other at the blanket mounting groove 20 and the position adjacent to the plate cylinder 1 and the blanket cylinder 2, and The mounting groove 10a ′ is in a rotational phase relationship where the blanket mounting groove 20 ′ and the plate cylinder 1 ′ and the blanket cylinder 2 ′ are opposed to each other at positions close to each other.

  The blanket mounting groove 20 is opposed to the blanket mounting groove 20 ′ on the blanket 21 ′ surface that is 180 degrees out of phase at a position sandwiching the continuous paper W1, and the blanket mounting groove 20 ′ is positioned between the blanket mounting groove 20 and 180. The portion of the blanket 21 that is out of phase is opposed to the portion on the surface of the blanket 21 at a position sandwiching the continuous paper W1.

  The ink form roller 5 has a nip pressure with respect to the printing plates 11a and 11b attached to the plate cylinder 1 and the printing plates attached to the plate cylinder 1 'and 11a' and 11b 'during printing. Therefore, in the same manner as the conventional one described with reference to FIG. 3, the inking roller 5 is provided with the printing plate mounting groove 10 in the rotation direction of the plate cylinder 1 in the rotation direction of the printing plates 11a and 11b and in the rotation direction of the plate cylinder 1 ′. , 11b ′, and descends along the trailing attachment end 102, and then suddenly rides on the preceding attachment ends 101 of the printing plates 11a and 11b in the rotation direction of the plate cylinder 1 and 11a ′ and 11b ′ in the rotation direction of the plate cylinder 1 ′. . At this time, useless ink remains on the leading attachment end 101 and the trailing attachment end 102.

  However, since the plate mounting grooves 10a and 10a 'face the blanket mounting grooves 20 and 20', the remaining ink does not transfer to the blankets 21 and 21 ', and therefore does not transfer to the continuous paper W1.

  On the other hand, the printing plate mounting grooves 10b and 10b ′ are opposed to the blanket mounting grooves 20 and 20 ′ and the portions of the blankets 21 and 21 ′ that are 180 degrees out of phase, and therefore remain on the leading mounting end 101 and the trailing mounting end 102. The ink is transferred to the opposite part of the blanket 21, 21 '.

  However, the portion of the blanket 21 where the ink remains is opposed to the continuous paper W1 by the rotation of the blanket cylinder 2. At this time, the blanket mounting groove 20 ′ of the adjacent blanket cylinder 2 ′ sandwiches the continuous paper W1 and the blanket 21 Since the phase relationship is opposite to the portion where the ink remains, they face each other. For this reason, the printing pressure of the portion of the blanket 21 where the ink remains is eliminated or remarkably reduced, and the residual ink of the blanket 21 is not transferred to the continuous paper W1 or very little to the extent that it cannot be visually observed.

  Similarly, the portion of the blanket 21 ′ where ink remains is opposed to the continuous paper W1 by the rotation of the blanket cylinder 2 ′. At this time, the blanket attachment groove 20 of the adjacent blanket cylinder 2 sandwiches the continuous paper W1 and the blanket 21 ′. Because of the phase relationship that opposes the remaining portion of the ink, it opposes. For this reason, the printing pressure of the portion of the blanket 21 ′ where the ink remains is eliminated or significantly reduced, and the residual ink of the blanket 21 ′ is not transferred to the continuous paper W <b> 1 or extremely small to the extent that it cannot be visually observed.

  In the above-described newspaper offset printing method according to each embodiment of the present invention, blankets 21 and 21 having a length in the circumferential direction that is twice the printing pitch printed by one printing plate 11a, 11b, 11a ′, and 11b ′. This is an offset printing method for newspapers in which a continuous paper W1 is sandwiched between two blanket cylinders 2 and 2 'to which' is attached, and the blanket mounting groove 20 (20 ') of one blanket cylinder 2 (2') is continuous. When the paper W1 is sandwiched, the blanket mounting groove 20 '(20) of the other blanket cylinder 2' (2) has a circumference corresponding to the printing pitch printed by one printing plate 11a, 11b, 11a ', 11b'. This is an offset printing method for newspapers in which two blanket cylinders 2 and 2 'are rotated in opposite directions with a phase relationship that is shifted in the rotational direction by the length in the surface direction.

  The above-described newspaper offset printing machine according to each embodiment of the present invention has two blanket cylinders 2 and 2 in which both end portions of the blankets 21 and 21 ′ are wound around the peripheral surface so as to be fixed by the blanket mounting grooves 20 and 20 ′. And plate cylinders 1 and 1 'in which both ends of the printing plates 11a, 11b and 11a' and 11b 'are wound around the peripheral surface so as to be fixed by the printing plate mounting grooves 10a, 10b and 10a' and 10b '. An offset printing press for newspapers, which is disposed adjacent to two blanket cylinders 2 and 2 ', and prints with a continuous paper W1 sandwiched between the blanket cylinders 2 and 2' adjacent to each other, and two blankets adjacent to each other The printing plate 11a or 1 having a length of 1 in the circumferential direction of the blankets 21 and 21 ′ to which the blanket mounting grooves 20 and 20 ′ of the cylinders 2 and 2 ′ are both attached. b, 11a ′ or 11b ′ is provided so as to be twice the printing pitch to be printed, and one printing plate 11a or 11b, 11a ′ is located at a position where the two blanket cylinders 2 and 2 ′ sandwich the continuous paper W1. Or 11b 'is the newspaper offset printing machine provided in the position shifted | deviated to the rotation direction only by the length of the circumferential direction equivalent to the printing pitch which prints.

  Next, another embodiment of the present invention will be described with reference to FIG. FIG. 2 is a newspaper offset printing machine, and is a perspective explanatory view of the main cylinder arrangement of the newspaper 2 pages × 4 pages wide and the phase relationship between the grooves as seen from above, and FIG. 3 shows ink in the printing plate mounting grooves of the plate cylinder. It is a fragmentary sectional enlarged view which shows the state with which the dosing roller opposes.

  In the plate cylinders 3 and 3 ′, there are plate mounting grooves each having a length from one end face N of the plate cylinders 3 and 3 ′ to the axial center M at two halves in the circumferential direction of the circumferential surface. 30a, 30b and 30a ', 30b' and the length from the other end face P to the axial center M at a position 90 degrees out of phase with the plate mounting grooves 30a, 30b and 30a ', 30b' in the circumferential direction. Plate mounting grooves 30c, 30d and 30c ′, 30d ′ forming the length are provided in parallel to the axis.

  The plate plates 31a, 31b, 31c, 31d and 31a ′ are provided by a plate mounting device (not shown) provided in each of the plate mounting grooves 30a, 30b and 30a ′, 30b ′, 30c, 30d and 30c ′ and 30d ′. 31b 'and 31c'31d' are attached. Inks are supplied to the printing plates 31a, 31b, 31c, 31d and 31a ', 31b', 31c'31d 'attached to the plate cylinders 3 and 3' by a plurality of ink form rollers (not shown).

  The blanket cylinders 4 and 4 ′ include blanket attachment grooves 40a and 40a ′ having a length from one end face N of the blanket cylinders 4 and 4 ′ to the axial center M, and the blanket attachment grooves 40a and 40a ′ and the periphery thereof. Blanket mounting grooves 40b and 40b ′ having a length from the other end face P to the axial center M are provided in parallel to the axis at a position 90 degrees out of phase in the plane direction. Blankets 41a and 41b and 41a 'and 41b' are attached by a blanket mounting device (not shown) provided in the blanket attachment grooves 40 and 40 '. A continuous paper W2 to be printed is sandwiched between the blanket cylinders 4 and 4 'so as to run in the direction of the arrow.

  Next, the phase relationship between the cylinders will be described. Of the printing plate mounting grooves 30a, 30b and 30c, 30d, the printing plate mounting groove 30a is in a rotational phase relationship facing each other in the proximity of the plate cylinder 3 and the blanket cylinder 4 with the blanket mounting groove 40a. Reference numeral 30 c denotes a rotational phase relationship in which the blanket mounting groove 40 b and the plate cylinder 3 and the blanket cylinder 4 are opposed to each other at positions close to each other.

  Similarly, of the printing plate mounting grooves 30a ′, 30b ′ and 30c ′, 30d ′, the printing plate mounting groove 30a ′ opposes the blanket mounting groove 40a ′ and the adjacent positions of the plate cylinder 3 ′ and the blanket cylinder 4 ′. The plate mounting groove 30c ′ is in a rotational phase relationship, and is in a rotational phase relationship in which the blanket mounting groove 40b ′ and the plate cylinder 3 ′ and the blanket cylinder 4 ′ are opposed to each other.

  The blanket mounting groove 40a is opposed to the blanket mounting groove 40a ′ and a portion on the surface of the blanket 41a ′ that is 180 degrees out of phase at a position sandwiching the continuous paper W2, and the blanket mounting groove 40a ′ is positioned between the blanket mounting grooves 40a and 180a. The portion on the blanket 41a surface whose phase is shifted is opposed to the portion sandwiching the continuous paper W2.

  Further, the blanket mounting groove 40b faces the blanket mounting groove 40b ′ at a position sandwiching the continuous paper W2 with a portion on the surface of the blanket 41b ′ that is 180 degrees out of phase, and the blanket mounting groove 40b ′ is positioned between the blanket mounting grooves 40b and 180b. The portion on the blanket 41b surface whose phase is shifted is opposed to the portion sandwiching the continuous paper W2.

  The ink form roller 5 is used for printing plates 31a, 31b and 31c, 31d attached to the plate cylinder 3 and printing plates 31a ', 31b' and 31c ', 31d' attached to the plate cylinder 3 'during printing operation. Has nip pressure. Therefore, the ink form roller 5 is attached to the printing plates 31a, 31b and 31c, 31d and the plate cylinder 3 ′ in the rotation direction of the plate cylinder 3 of the printing plate mounting groove 10 in the same manner as the conventional one described with reference to FIG. The printing plates 31a ', 31b' and 31c ', 31d' fall along the trailing attachment end 102, and then the printing plates 31a, 31b and 31c, 31d and the plate cylinder 3 'rotate in the rotation direction of the plate cylinder 3. The plate 31a ', 31b' and 31c ', 31d' in the direction suddenly rides on the leading attachment end 101. At this time, useless ink remains on the leading attachment end 101 and the trailing attachment end 102.

  However, since the printing plate mounting grooves 30a and 30a ′ are opposed to the blanket mounting grooves 40a and 40a ′, and the printing plate mounting grooves 30c and 30c ′ are opposed to the blanket mounting grooves 40b and 40b ′, the remaining ink is removed from the blanket 41a and It does not shift to 41a 'and therefore does not shift to the continuous paper W2.

  On the other hand, the plate mounting grooves 30b and 30b ′ face the portions of the blankets 41a and 41a ′ that are 180 degrees out of phase with the blanket mounting grooves 40a and 40a ′, and therefore remain on the leading mounting end 101 and the trailing mounting end 102. The ink is transferred to its opposite part of the blankets 41a and 41a ′.

  However, the portion of the blanket 41a where ink remains is opposed to the continuous paper W2 by the rotation of the blanket cylinder 4. At this time, the blanket mounting groove 40a ′ of the adjacent blanket cylinder 4 ′ sandwiches the continuous paper W2 and the blanket 41a Since the phase relationship is opposite to the portion where the ink remains, they face each other. For this reason, the printing pressure of the portion of the blanket 41a where the ink remains is eliminated or significantly reduced, and the residual ink of the blanket 41a is not transferred to the continuous paper W2 or becomes extremely small to the extent that it cannot be visually observed.

  Similarly, the ink remaining portion of the blanket 41a ′ is opposed to the continuous paper W2 by the rotation of the blanket cylinder 4 ′. At this time, the blanket mounting groove 40a of the adjacent blanket cylinder 4 sandwiches the continuous paper W2 and the blanket 41a ′. Because of the phase relationship that opposes the remaining portion of the ink, it opposes. For this reason, the printing pressure of the portion of the blanket 41a 'where the ink remains is eliminated or remarkably reduced, and the residual ink of the blanket 41a' is not transferred to the continuous paper W2 or very little to the extent that it cannot be visually observed.

  When the plate mounting grooves 30d and 30d ′ are opposed to the blankets 41b and 41b ′, the ink remaining on the leading mounting end 101 and the trailing mounting end 102 is 180 ° out of phase with the blanket mounting grooves 40b and 40b ′. Of the blanket 41b and 41b 'of different.

  However, the portion of the blanket 41b where the ink remains is opposed to the continuous paper W2 by the rotation of the blanket cylinder 4. At this time, the blanket mounting groove 40b ′ of the adjacent blanket cylinder 4 ′ sandwiches the continuous paper W2 and the blanket 41b Since the phase relationship is opposite to the portion where the ink remains, they face each other. Therefore, the printing pressure of the portion of the blanket 41b where the ink remains is eliminated or extremely low, and the residual ink of the blanket 41b does not transfer to the continuous paper W2 or becomes extremely small to the extent that it cannot be visually observed.

  Similarly, the ink remaining portion of the blanket 41b ′ is opposed to the continuous paper W2 by the rotation of the blanket cylinder 4 ′. At this time, the blanket mounting groove 40b of the adjacent blanket cylinder 4 sandwiches the continuous paper W2 and the blanket 41b ′. Because of the phase relationship that opposes the remaining portion of the ink, it opposes. For this reason, the printing pressure of the portion of the blanket 41b 'where the ink remains is eliminated or remarkably reduced, and the residual ink of the blanket 41b' is not transferred to the continuous paper W2 or very little to the extent that it cannot be visually observed.

  In the embodiment shown in FIG. 2, the printing plate mounting grooves 30a, 30b and 30a ′, 30b ′ and the printing plate mounting grooves 30c, 30d and 30c ′, 30d ′ are in a positional relationship that is 90 degrees out of phase in the circumferential direction. Yes, the blanket mounting grooves 40a and 40a 'and the blanket mounting grooves 40b and 40b' are also in a positional relationship that is 90 degrees out of phase in the circumferential direction, but the phase deviation angle in the circumferential direction is limited to 90 degrees is not.

  The above description is about a newspaper offset printing machine in which the plate cylinders 1, 1 'and 3, 3' and the blanket cylinders 2, 2 'and 4, 4' both have a two-page circumference of the newspaper. The effective surfaces of the blankets 21, 21 'and 41a, 41b, 41a', 41b 'mounted on the cylinders 2, 2' and 4, 4 'are 1 mounted on the plate cylinders 1, 1', 3, 3 '. In the offset press for newspapers, the printing plates 11a, 11b, 11a ', 11b' and 31a, 31b, 31c, 31d, 31a ', 31b', 31c ', 31d' are twice the effective surface of the pitch to be printed. Applicable.

  INDUSTRIAL APPLICABILITY The present invention can be used for offset printing of newspapers in which a continuous paper is sandwiched between two blanket cylinders to which a blanket having a length in the circumferential direction twice the printing pitch printed by one printing plate is attached. is there.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Embodiment of this invention, Front explanatory drawing which showed the main cylinder arrangement | positioning of a newspaper 2 page length x 2 page width, and the phase relationship of a groove | channel It is a figure which shows other embodiment of this invention, and is the perspective explanatory drawing which looked at the phase relationship of the main cylinder arrangement | positioning and groove | channel of newspaper 2 page length x 4 page width from diagonally upward Partial enlarged cross-sectional view showing the state where the ink form roller faces the plate mounting groove of a normal plate cylinder

Explanation of symbols

1, 1 'plate cylinder 10a, 10b, 10a', 10b 'printing plate mounting groove 11a, 11b, 11a', 11b 'printing plate 2, 2' blanket cylinder 20, 20 'blanket mounting groove 21, 21' blanket 3, 3 'plate cylinder 30a, 30b, 30c, 30d printing plate mounting groove 30a', 30b ', 30c', 30d 'printing plate mounting groove 31a, 31b, 31c, 31d printing plate 31a', 31b ', 31c', 31d ' Printing plate 4, 4 'blanket cylinder 40a, 40b, 40a', 40b 'Blanket mounting groove 41a, 41b, 41a', 41b 'Blanket 5 Inking roller 101 Printing plate preceding mounting end 102 Printing plate trailing mounting end W1 , W2 Continuous paper N One end face of each cylinder M Center of each cylinder in the axial direction P The other end face of each cylinder

Claims (2)

In an offset printing method for newspapers, printing is performed by sandwiching continuous paper between two blanket cylinders to which a blanket having a circumferential length twice as long as a printing pitch printed by one printing plate is attached.
When the blanket mounting groove of one blanket cylinder is in a position to sandwich continuous paper, the blanket mounting groove of the other blanket cylinder is shifted in the rotational direction by the length in the circumferential direction corresponding to the printing pitch printed by one printing plate. An offset printing method for a newspaper, characterized in that printing is performed by rotating two blanket cylinders in opposite directions with a phase relationship at a different position. Two blanket cylinders that are wound around the peripheral surface so that both ends of the blanket can be fixed by the blanket mounting groove are adjacent to each other, and two plate cylinders that are wound around the peripheral surface so that both ends of the plate can be fixed by the plate mounting groove are provided. In a newspaper offset printing machine that is arranged adjacent to each blanket cylinder and prints with continuous paper sandwiched between adjacent blanket cylinders,
The blanket mounting grooves of the two blanket cylinders adjacent to each other are provided so that the length of the blanket attached to each blanket is twice the printing pitch on which a printing plate with one printing plate is printed,
An offset printing press for newspapers, characterized in that two blanket cylinders are provided at positions shifted in the rotational direction by a length in the circumferential direction corresponding to the printing pitch on which one printing plate prints relative to the position where the continuous paper is sandwiched. .

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