JPS5949973A - Water supplying device for offset printing plate surface - Google Patents

Abstract

PURPOSE:To enable to print at a high speed with high quality without using any alcohol, by roughening the surface of an ink layer by a specified roughened surface type roller immediately before transferring damping water onto the first form roller from a water fountain roller or the like. CONSTITUTION:An ink-vibrating roller 4, the roughened surface type roller 13 provided with minute rugged parts over the entire surface of the roller and either the water fountain roller 3 or a metering roller 2 are sequentially rotated by sequentially bringing into contact with the peripheral surface of the first form roller 1 rotated at a circumferential speed equal to that of a form cylinder while making contact with a printing plate provided on the form cylinder, along the rotating direction of the roller 1. The roller 13 is preferably a roller provided with a plurality of rugged parts in the form of dots, lines, net, satin, sand grain or the like with a width or diameter of the recessed or protuberant part of not larger than 3mm. and a depth or height of 10mum-2mm. over the substantially entire part of the circumferential surface thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water supply device for an offset plate surface that supplies dampening water to a plate on a plate cylinder of an offset printing press without using alcohol.

A typical dampening water supply device for an offset printing machine is
In contrast to the water fountain roller, chrome roller, vibrator roller, and swimwear, which supply dampening water directly to the printing plate surface via roller #, the same roller (No. 1 N
For example, a Daaldalen type dampening water supply device is different from this, in that the ink is deposited from the water base roller and the chrome roller to the roller (the first stage is the roller) (!-) and then onto the printing plate surface with the ink. It supplies dampening water,
The dampening water is first transported on the surface of the ink on the roller or inside the ink layer in the form of a thin droplet or water droplet, which is surrounded by the ink. At the tangent to the plate, the impact force causes the ink to be partially ejected from the ink layer and wet the non-image areas on the plate, and the repulsion of water and oil allows for lithographic printing.

In other words, in the first place, the ink layer on the roller repeatedly absorbs and releases dampening water, and is thought to temporarily serve as content.
To achieve this, the ideal amount of dampening water must be transferred to the printing plate uniformly and at high speeds at the same time as the ink, so the bonding relationship between the ink and dampening water and its balance must be I've become able to take things seriously.

Conventionally, in the Dahlgren method, 5 to 20% of alcohol such as Inglobil alcohol is mixed into the dampening water to lower the surface tension of the dampening water and increase the emulsification of the dampening water into the ink and the possibility of sticking and chipping. In this way, a method was adopted to maintain the balance between ink and water. However, as printing speed increases, the total amount of alcohol mixed must increase, and there is also loss during printing, so care must be taken to manage the alcohol mixing ratio. It's a shame that environmental health problems will arise. Also, the price is high, the halftone dots of the printed matter are too high, and the ink has poor alcohol resistance.
This had many drawbacks, such as staining. II K Study ^・Hyakusha, Part 1 Ga 1
Before transferring the dampening water from the water base roller or metering roller onto the water roller, the alcohol is added by roughening the surface of the ink layer using specific i, l if+i type rollers. The present invention was completed by discovering that it is possible to obtain high-quality printed matter at high speed without using any of the above materials, and to solve the various defects mentioned above.
The first plate rotates at the same circumferential speed as the plate cylinder.
Arrival is carried out in the rotation direction of the roller around one circumference of loaf 1.
First, the ink vibrator rollers 4 are rotated in tandem, then the interfacial roller 3 having fine irregularities on almost the entire surface of the roller is rotated in tandem, and finally the water bubble is rotated in tandem.

This is a water supply device for an offset printing plate, in which either the metering roller 2 or the metering roller 2 is brought into contact with each other and rotated.

Basics of the Thahlgren system 47 As shown in Figure 1, the first layer is dampened from the water source roller 3 applied to roller 1 (-1 film of water on metering roller 2) F4. The method of supplying water is mainly used for single-fed cutting, and the first one is mowed by roller 1, as shown in Figure 2.

There are two methods for supplying dampening water from the water base roller 3 through the metering roller 2.The method is used for off-wheel presses and sheet-fed Me. Since the membrane and water membrane are in contact at the area A1 in Figure 1 and A1 in Figure 2, which is the point immediately before they come into contact with each other, this is the basic feature of the Dahlgren system (Q, It can be used regardless of i.

In FIG. 2, ink supplied from an ink fountain, an ink mixing roller, etc. (not shown) is transferred to an ink vibrator roller 4.
, the first place is supplied with ink by roller 1, the second place is by roller 5, the third place is by roller 6, and the fourth place is supplied with ink by 7 rollers. -/The dampening water tank installed parallel to the plate cylinder 9 ■The water source r1-ra3 rotates while partially immersed in the dampening water 11 in the plate cylinder ■0, and the water source r1-ra3 rotates while in contact with this. The first dampening water 11fd is supplied to the roller 1 by the metering roller 2. dampening water 1
1 is regulated by the nip pressure between the water base roller 3 and the metering roller 2; It is difficult to transfer the leftover water onto the ink film +t+i+2, which is the repelling thread component, so mix alcohol into the dampening water and shake the metering roller 2! Methods such as 1jJJ were also tried, but the use of alcohol caused the above-mentioned defects, and other methods did not yield good results.

In the first step, an ink layer 12, which is supplied from an ink fountain through a number of rollers, is attached to the surface of the roller. This ink layer 12 differs depending on the printing (1) note, but when there is a large number, the number is 1.
00 μm thickness 0 Measuring roller 2 Dampening water on the clothing surface 111: J1. Emulsified into the ink layer 12 with the help of alcohol in dampening water! The rate of transfer of dampening water to the printing plate 8 depends on the alcohol content, ink components, 11" printing temperature, temperature storage, etc. ,
It tends to fluctuate due to humidity and various other factors, and depending on the design of the print, there may be differences in the ink film thickness and moisture adhesion amount on the roller 1 at the beginning of printing, making it difficult to control the quality and efficiency of the print. It became difficult to use alcohol, and the harmful effects of alcohol use were increasing.

Therefore, it has been considered to swing the control roller 22 from side to side, or to make the surface of the metering roller 2 rough.
With this method, no effect was obtained, and no fL was obtained. This is 0. j: , the first step is roller 1, i rotation j ((
A strong two-prong pressure is already working on the part 13 where the row 22 contacts, so even if another force is applied to this part, it will not
) It is assumed that there is no reed effect.

The present invention is shown in a schematic enlarged view in FIG. 3. Since the first roller 1 is rotating while being in contact with the rough-surfaced roller 13 according to the present invention, the surface of the ink layer 12 is rough-surfaced. The dampening water 11 that has been supplied to the surface of the mouth roller 13 is distributed between the roller 1 and the metering roller 2 by the irregularities 15v on the surface of the ink layer 12. i ＃'L It shows a heavy weight like that of the ink J@16 and is easily mixed, sweated, and deposited on the inside of the ink J@16 and its surface, and is evenly transferred to the plate 8 with a high transfer rate.
will be transferred to.

Due to the inventive concept, the mixing and adhesion of ink and dampening water are extremely difficult and very difficult to achieve, so it is not affected by printing speed, ink composition, printing room environment, and other factors.
It has become possible to supply the optimum amount and uniformly without using alcohol at all.

For this reason, although the sanitary problems caused by the use of alcohol can be completely eliminated, in the conventional method, the ink tends to emulsify due to the influence of alcohol, and the release of dampening water when the 17th ink roller comes into contact with the plate is difficult. Because it is defective, each ink mixing roller is moved to the next 81 years i:+r, water gets around and emulsifies the ink, which deteriorates the ink's physical properties such as fluidity, tack, and stiffness. Printed product T (low F
Prevention has also become a problem.

Rough surface roller 131 used in the present invention. L, preferably a roller having a hydrophilic metal layer such as chromium or aluminum on its surface, and having many uneven portions with a diameter or width of 3 nm or more and a depth of 0μ to 2111111 on almost the entire surface. There must be.

If the diameter or width of the uneven portion is 3 mm or more, the first layer will have a sparse portion of unevenness 11 applied to the ink surface 12 on the roller.
If it is too small, the effect of 1 non-invention will be lost, so 3 mm or less is preferable (, 'l + * m or less is even more preferable. However, if this is 100 μ or less, A
, III Kazukiru also obtained the effect 7.
R. Father, the height (taste) of the uneven part is 10μ~2unn
If the amount is less than 1, the whitening effect on the surface of the ink layer 12 cannot be expected, and on the other hand, if it is too deep, it will be difficult to control the amount of moisture on the plate 8, which is inappropriate. .

Irregularities x4r, J: Parallel to the axial direction, oblique, straight, meandering, dotted line shape,
Any shape can be used as long as it is irregular, dotted, satin-like, net-like, grainy, etc., or a combination of these, such as grooves or dots. As long as almost the entire surface of the sieve is provided with concavo-convex portions with the same pitch and depth according to the invention, it can be used.

The uninvented water supply device is 311 times larger than the conventional Thalgren system.
With the simple improvement of just installing one new planar row 213, we are able to improve the environmental impact by eliminating the need to replace the high 1+Ili alcohol, which was required by the conventional Thalgren method. 7J printing problems are resolved, printing workability is improved, ink transfer rate is improved, and halftone dots become clearer. It is possible to see the unexpected effect that many problems are solved at the same time, such as no staining even when more than one sheet is continuously rotated, and high-crystal negative printed matter is obtained.

[Brief explanation of the drawing]

Fig. m1 and Fig. 2 are partial side views showing the Thalgren type water supply system during printing Φ, and Fig. 3 is a side view of the main parts of the present invention. Main symbols t, ti, J: 1st stage is roller, 2 is metering roller, 3 is water base roller, 4t ink vibrator roller, +1 is plate, 11 is dampening water, 12 is ink ,1
3 indicates a rough-surfaced roller. Conventional Bi hay > Person Tokyo Ink Co., Ltd. Toshiaki Kamiotani

Claims (1)

[Claims] 1. A first plate that is in contact with the plate on the plate cylinder and rotates at the same circumferential speed as the plate cylinder.
The ink vibrator roller is first brought into contact with the circumferential surface of the roller, then the rough-surfaced roller is brought into contact with the peripheral surface of the roller, and then either the water base roller case or the metering roller is brought into contact with the circumferential surface of the roller. Features a water supply device to the offset printing plate. 2. As a rough-surfaced roller, the width of concave or convex portions on almost the entire circumferential surface, -! Patent for using a roller having a diameter of 3 mm or more and a large number of dotted, linear, net-like, satin-like, sand-grained, etc. irregularities with a depth or height of 10 μm to 2 +++ m A water supply device for an offset printing plate according to claim 1.