JPS61148059A - Printing method of letter set - Google Patents

Abstract

PURPOSE:To make possible a plate to be mounted and dismounted to and from a printing drum as easy as a lithoprinting plate with an offset printing machine for a conventional lithoprinting is used, by providing a plate material for a letter set printing having a whole thickness of less than 0.35mm with a specific supporting plate is used, and by making a bending angle of the plate of a plate bending machine smaller by a specified amount than a conventional angle. CONSTITUTION:A plate 11 bended by a plate bending machine in which an angle of a plate angle adjusting plate 16 on a holding side is set by 5-20 deg. smaller relative to a grooving angle 21 for a plate to be inserted groove at a holding section of a printing drum 6 of an offset rotary press using a light sensitive resin relief printing making an iron plate of a tensile strength of more than 55kg/mm<2>, an elongation ratio of less than 10%, and a thickness of 0.03-0.14mm as a supporting body is used. In such a manner, a stain of the matter to be printed owing to a stick of an ink at a holding section is not generated, when a letter set printing is carried out with the offset rotary press is used, and the letter set printing using the photosensitive resin lithoprinting can be carried out easy with the offset rotary press using the conventional flat plate is used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of printing using an improved photosensitive resin material for letterset printing.

(Prior Art) Lithographic printing has replaced letterpress printing as the current mainstream printing method, but because it uses dampening water.

There are some problems. For example, at the t-th point of emulsification of the ink, the feather l/i-j'ij'lh<k
It takes a long time to convert the + and - marks into one lull, and a large amount of paper is wasted.

Additionally, moisture affects paper dimensions, which is a major problem in fields that require high dimensional accuracy.

Furthermore, in recent years, special inks and papers have been developed and put into practical use one after another, but the presence of water in lithographic printing is always a problem in printing using these.

In order to solve these problems, a letter set printing method, also known as letterpress dry offset, was proposed, which uses a letterpress plate and transfers it onto a blanket without using water for offset printing. It has advantages such as excellent printing reproducibility and is being put into practical use.

However, the conventional photosensitive resin letterpress used for letter set printing has the following problems with the plate composition due to the material of the support, and it has not been widely used like planographic printing that uses water. Not yet reached.

In other words, the support of the photosensitive resin layer has a normal pressure buoyancy #E.
Mealta Akira 2' is used to firmly and stably support the photosensitive resin after photocuring that makes up one print area, prevent bending and unevenness, and maintain the smoothness of the plate surface. The thickness of the support was required to be 0.15 mm or more. Furthermore, the thickness of the photosensitive resin layer is preferably 0.2 mm or more, similar to the letterpress material, in order to avoid ink stains in non-image areas.

Therefore, the total thickness of the 9th plate material is 0.15 +0.2 = 0.5
5 wn or more, which is too thick compared to the mainstream planographic plates with a thickness smaller than this, making it difficult to install on offset printing machines and requiring the preparation of special cylinders, which has hindered its widespread use. This is a major factor. Therefore, the present inventors have overcome these problems and have developed an ultra-thin offset printing machine that can perform dry offset printing by simply removing the dampening water supply mechanism and without making any modifications to a normal offset printing machine for planographic plate materials. As a result of intensive study on the development of photosensitive resin plate material for letter set printing, the tensile strength was 55 kg.
/=2 or more, elongation rate is 10% or less, and the thickness is 0.03 to 0.1. Proposed.

The letter set printing plates currently in use include:
As a support, the tensile strength is 50 kg/mm or more ~ 55 k
An iron plate with an elongation rate of less than g/mm and more than 10% is used, and in order to ensure its function as a support, the thickness must be 0.15 nm+ or more.

Adding 0.2 on of photosensitive resin layer to this, 0.35-
The above is the thickness of the letterpress material.

In contrast, the tensile strength of the present invention is 55 kg/mm or more, which allows the thickness of the photosensitive resin layer to be reduced to 0.2 kg/mm or more.
A photosensitive resin plate material for extremely thin letter set printing with a total thickness of 0.35 mm or more and a total thickness of 0.35 mm or more has become available for practical use.

If the tensile strength of the iron plate that is the support is less than 55 kg/mm and the elongation rate is more than 10%, it will be easily deformed and will be less practical. In addition, if the tensile strength is 55 kg/mto or more, there is a problem in attaching the plate to the letter, and if the thickness is less than 0.03 mm, the function as a support is poor.

None of them meet the objectives of the present invention.

However, according to the present invention, the thickness can be reduced to 0.0 mm, which was previously impossible.
It is possible to provide letter set printing plates with the same thickness as general planographic plates such as 24rIXn and 0.30mm, and can be used for printing on ordinary sheet-fed offset printing presses and rotary offset printing presses. .

However, when a plate is mounted on an offset rotary printing machine in the same manner as a lithographic printing plate, the plate on the edge and tail of the plate lifts up, and the rollers cause the ink to adhere to non-image areas where ink should not normally be attached. , which is also transferred to the blanket and stains only one part of the paper, is called smudge. This stain will significantly impair print quality and have no commercial value.

It turned out to be a major factor hindering its spread.

Therefore, the present inventors have overcome this problem.

As a result of intensive study on a printing method that allows letter set printing by simply removing the dampening water supply mechanism without making any modifications to a normal offset rotary printing press for lithographic plate materials, we developed a plate bending machine for an offset rotary press. It was discovered that the objective could be achieved by making the plate bending angle smaller than that of the conventional one, and based on this knowledge, the present invention was completed.

Measures to solve problem C) In letter set printing by an offset rotary press using a photosensitive resin letterpress plate as a support, the groove cutting angle of the plate insertion groove at the gripping part of the plate cylinder of the offset rotary press In contrast, this is a letter set printing method characterized by using a plate bent by a plate bending machine in which the angle of the occlusal plate angle shaping plate of the 9 plate bending machine is set smaller by 5° to 20°.

term + mercenary blue mopu Iλ2 so I gizo p ↓1 top 1 su 9 When the photosensitive resin letterpress plate of the present invention is bent (grooving angle for inserting the plate at the gripping part of the plate cylinder of an offset rotary press + 10 degrees), the angle becomes 9 when the plate is installed. It was found that by wrapping the butt of the plate with a stick, it came into contact with the plate insertion groove on the biting side, and the biting side of the 9th plate was lifted up.

Therefore, when using the photosensitive resin letterpress plate of the present invention, the angle of the plate angle shaping plate on the bite side of the plate bending machine should be adjusted relative to the groove cutting angle of the plate insertion groove at the bite part of the plate cylinder of the offset rotary press. If it is the same or smaller, the plate edge side will rise, which is undesirable, and if it is made smaller than 20, it will be difficult to insert it into the plate 9 insertion groove. Therefore, it is an object of the present invention to provide a letter set printing method characterized in that a plate bending machine is conveniently set in a range of 5° to 20' smaller, more preferably 106 to 156° smaller.

Below, nine embodiments of the present invention will be explained based on the drawings.
Figure 1 is a cross-sectional view of a conventionally used offset rotary press, and Figure 6 is a cross-sectional view of the plate cylinder of the offset rotary press.
FIG. 2 shows a sectional view of the plate bending machine of the offset rotary press.

A typical offset rotary press receives a predetermined amount of ink from an ink fountain 1 with a feed roller 2.

The ink kneaded by the kneading roller 3 reaches the ink-receiving area of the printing plate from the roller 4. Also, to prevent the ink from adhering to the non-image areas of the printing plate, a hydrophilic ink containing water as the main component is supplied from a water supply device to prevent the ink from adhering to the non-printing area of the printing plate. An aqueous solution of is supplied.

Note that in the letter set printing of the present invention, this water supply device is not necessary. The first plate cylinder 6 is used to attach a plate to the plate cylinder 6.
A plate insertion groove 7 is cut in the plate.

Reference numeral 8 is called the blanket cylinder, which has the role of transferring the ink that has arrived on the printing area of the first plate, and 9 is usually made of elastic rubber. The contact pressure between the plate cylinder 6 and the blanket cylinder 8 can be changed mechanically as desired.

Next, a web 10 is continuously passed between the blanket cylinder 8 and the impression cylinder 9, and the image transferred to the blanket cylinder 8 is continuously printed on the paper.

, I would like to explain in more detail how to install the plate.

First, the 9th plate bending machine (
It is necessary to bend the plate in advance (Fig. 2).

If the plate is twisted, it cannot be corrected, so if you place plate 11 on the 9th plate bending machine and match the upper and lower register marks exactly with the marks on the plate bending machine, the 9th plate will not be twisted. Hold it with the clamp 12 so that it does not move, and then tighten the occlusal side clamp 16 and the occlusal side clamp 1.
Press 4 to press the plate. Next, hold the gripping side of the plate and bend the plate 1
5 until it hits the plate angle shaping plate 16 on the bite side, which is made at the same angle as the groove cutting angle for plate insertion at the bite part of the plate cylinder of the offset rotary press. Similarly, the jaws 18 are generally at the same angle so that they can be used as the angle shaping plates 16 for the jaw side.

The bending angle of the plate on the butt side should be such that it can be easily inserted into the groove for inserting the plate, and a strict plate bending angle is not required.

The plate bent in this manner is attached to the plate cylinder 6, and the first plate cylinder (FIG. 3) will be explained.

A tangent 20 is drawn on the circumference of the plate cylinder using the plate insertion groove grip side 19 as a base point, and the angle 21 created between the tangent 20 and the plate insertion groove grip side 19 is defined as the angle 21 between the plate insertion groove grip side 19 of the offset rotary press. The groove cutting angle of the plate insertion groove at the edge portion is called 2,1. This plate insertion groove generally has a width of 1 to 3 inches and a depth of 10 to 40 inches.

A plate winding rod 22 is provided at the back of the plate insertion groove for inserting the end of the plate and winding up the nine plates.

To install the plate, first insert the 9th plate into the 1st plate insertion groove on the bite side 19.
The 9th plate cylinder is rotated toward the blanket cylinder, the 1st plate cylinder and the blanket cylinder are brought into contact, and the 1st plate cylinder is slowly rotated once so that the 1st plate is in close contact with the plate cylinder. Next, insert the butt end of the plate into the groove for inserting the 9th plate, insert the butt end of the 1st plate into the groove of the plate winding rod 22, and then rotate the 9th plate winding rod 22 so that the plate comes into close contact with the 1st plate cylinder. do.

The plate mounting method in which the plate 11 is brought into close contact with the plate cylinder 6 using the plate winding rod 22 at the end of the plate in this manner is called a roll-in type.

The other plate mounting method is called the insertion type, and the method of attaching the bite of the 9th plate is the same, and the butt end of the 1st plate is simply inserted into the plate insertion groove. In this case, the groove for inserting the plate generally has a width of 1 mm or less and a depth of 6 mm to 6 mm. Because the width of the insertion groove is narrow in this way, and because pressure is applied to the roller and blanket cylinder in order from the bite side of the 9th plate to the butt side, the 9th plate is printed in close contact with the plate cylinder. . This method has recently become popular because the unprinted area is small, less than 1 mm, and the plate mounting operation is simple.

The above is an overview of a typical offset rotary printing press and the method of attaching the plate to the plate cylinder.

In the present invention, the angle of the bite side plate angle shaping plate of the 9 plate bending machine is set to be 5° to 20'' smaller than the groove cutting angle of the plate insertion groove at the bite part of the plate cylinder of the offset rotary press. Use a plate bent with a plate bending machine.

By doing this, even if letter set printing is performed using an offset rotary press, there will be no stains on the printed matter due to ink adhering to the gripping area, and photosensitive resin letterpress can be printed using a conventional offset rotary press using a lithographic plate. It becomes possible to easily perform letter set printing.

An example will be explained below, and the printing plate used as a support had a tensile strength of 65 kg/wn and an elongation rate of 1.7%.
.

A polyester/isocyanate adhesive with a dry film thickness of 0.02 was applied to Zinc Fast Steel with a thickness of 0.09, and then partially saponified polyvinyl acetate with a degree of saponification of 75 molar and a degree of polymerization of approximately 600 was applied. as a base polymer, propylene glycol diglycidyl ether acrylate as a photopolymerizable monomer, benzyl dimethyl ketal as a photosensitizer, and diethylene glycol as a plasticizer to form a photosensitive resin with a dry film thickness of 0.21 mm. A general negative film for cash receipts was vacuum-adhered on top, exposed for 2 minutes using an ultra-high-pressure mercury lamp, and then processed using a brush developing machine filled with neutral water.
Completely elute the unexposed areas and incubate in a 50°C oven for 10 minutes.
A relief plate for letter set printing was used which had been thoroughly dried for 1 minute and post-exposed for 2 minutes using an ultra-high pressure mercury lamp.

Example 1. Comparative Example 1 Ukita Kogyo Co., Ltd. offset form printing machine “0W-
201CTJ C The groove cutting angle of the plate insertion groove at the bite part of the plate cylinder is 50° (2 plate cylinder circumference is 11 inches), and the bending angle of the bite of the photosensitive resin letterpress plate of the present invention is 40'.

5!5', 30°, 20', and 15°, and the bending angle of the bite of a conventional lithographic printing plate was set to the usual 60°. The angles of the occlusal plate angle shaping plate of the plate bending machine are the usual 60'', 27, 5°, 25', 20°, 10°, and 5, respectively.
The angle of the occlusal plate angle shaping plate of a conventional plate bending machine for lithographic printing plates was set to 60°.

Table 1 (Note) The numbers in parentheses indicate the angle of the occlusal version angle correction version.

From the results in Table 1, it can be seen that the bending angle of the bite of the photosensitive resin letterpress of the present invention is 30 degrees, and the angle of the plate shaping plate on the bite side of the first plate bending machine is 30 degrees. It has been found that when a plate bent by a plate bending machine with a setting of 5° to 20° smaller is used, no bite stains occur.

Example 2. Comparative Example 2 Miyakoshi Kikai Seisaku Co., Ltd. Kuma Deminar type offset rotary press "
9 The bending angle of the bite of the photosensitive resin letterpress plate of the present invention was set to 70':67' using the "Demi-Off" (groove cutting angle of the plate insertion groove at the bite part of the plate cylinder 60 degrees 9 plate cylinder circumference 11 inches). :65°, 6
0', 50°, and 40', and the degree of bending of the lithographic plate was set to the usual 60°. The angles of the occlusal plate angle shaping plate of the 9th plate bending machine are the usual 60°, 57°, and 556°, respectively.
The angles were set to 50', 45', and 40°, and when a conventional lithographic printing plate was used, the usual 60° was used.

Table 2 From the results shown in Table 2, the bending angle of the bite of the photosensitive resin letterpress plate of the present invention is 60″, and the plate angle adjustment on the bite side of the plate bending machine is 60″. It has been found that when a plate bent by a plate bending machine in which the angle of the plate is set to be 5 to 20 degrees smaller is used, no bite stains occur.

(Effects of the Invention) According to the present invention, a specific support is used, which was difficult to achieve in the past. It is possible to provide letter set printing plates with a total thickness of 0.65 or less, and with only a partial modification of the plate bending machine, the printing method can be changed from conventional lithographic printing by simply removing the dampening device of the offset printing press. Using an offset printing machine, the plate can be easily attached to and removed from the plate cylinder, similar to a lithographic printing plate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an offset rotary press. FIG. 2 is a cross-sectional view of the plate bending machine of the offset rotary press. FIG. 3 is a sectional view of the plate body of the offset rotary press. 1: Ink fountain 2: Calling roller 6: Kneading roller 4: Ink roller 5: Water supply device 6
: Plate cylinder 7: Plate insertion groove 8: Blanket cylinder 9: Impression cylinder
10: Rolling paper 11: Plate 12: Clamp 13: Biting side clamp 14: Biting end side clamp 15: Biting plate bending fitting 16: Biting side version angle shaping plate 17: Biting bottom side plate bending fitting 18: Biting part Bottom side plate angle shaping plate 19: Plate insertion groove Biting side 20: Tangent line 21: Cutting angle of the plate insertion groove at the biting part of the plate cylinder of an offset rotary press 22: Plate winding rod Patent applicant Azuma Shi Co., Ltd. Company rod 7 times

Claims (1)

[Claims] Tensile strength 55kg/mm^2 or more, elongation rate 10% or less,
The cutting angle of the plate insertion groove at the gripping part of the plate cylinder of an offset rotary press using a photosensitive resin letterpress plate supported by an iron plate with a thickness of 0.03 to 0.14 mm is determined by the plate bending machine. A letter set printing method characterized by using a plate bent by a plate bending machine in which the angle of the occlusal plate angle shaping plate is set to be smaller by 5° to 20°.