JPS62256656A - Apparatus for coating printed matter with varnish - Google Patents

Abstract

PURPOSE:To obtain a varnish applying apparatus generating no irregularity in the varnish film on the surface of printing paper and capable of adjusting the thickness of the varnish film over a wide range, by constituting said apparatus so that a rubber cylinder, a form roller, a transfer cylinder an a metering roller are contacted with each other in this order to be respectively rotated to specific directions and varnish is supplied to the opposed contact part of the form roller and the transfer cylinder from above. CONSTITUTION:A part of the varnish B supplied from a supply member 6 passes between a form roller 3 and a transfer cylinder 4, and the other part D thereof passes between the transfer cylinder 4 and a metering roller 5. These varnishes meet at the lower part of the opposed contact part of both of the roller 3 and the cylinder 4 to form varnish A which is, in turn, carried to the supply side of the form roller 13 to be transferred to a rubber cylinder 2. In this case, the amount of the varnish B is made more than that of the varnish A so as to generate stagnation of varnish above the opposed contact part of the roller 3 and the cylinder 4. Because the varnish is generated above the opposed contact part of the roller 3 and the cylinder 4, the thickness irregularity of the varnish film on the form roller 3 due to the notch part or small window of the rubber cylinder 2 is eliminated by passing the varnish film on the roller 3 through the stagnation part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for applying varnish to printed materials produced by printing presses, in particular rotary printing presses.

BACKGROUND OF THE INVENTION The application of varnish to printed materials produced by rotary printing presses has been practiced for a long time, and has two main purposes. Ml does not use spray powder, which may result in higher quality prints. This is because spray powder causes the surface of printed matter to lose its luster, resulting in poor quality. The second purpose is to prevent printed matter from turning over, improve stacking performance of printed matter, and increase productivity. In other words, in the past, as the speed of printing presses increased, paper sheets piled up on the output side of the printing press, which caused back-up, so to prevent this, slatting (board-cutting) work was performed; puts a heavy burden on workers,
This was a major factor in reducing productivity in post-processes.

The idea is to eliminate this type of slatting work by applying varnish.

Typical examples of such varnish applicators have been known in the past, such as those shown in FIGS. 5 to 7, and these will be briefly described.

In these, 1 indicates an impression cylinder of a printing press, and the printed paper passes between this impression cylinder 1 and a blanket cylinder 2 which is opposite to this and rotates in the same direction, and at this time, the rubber The cylinder 2 applies varnish A to its surface.

Among these devices, the one shown in FIGS. 5 and 6 includes a forming roller 13, a welding roller 14, 24, and a base roller 1B, which are placed in contact with each other between the blanket cylinder 2 and the varnish storage tray 16.
.

Of these, the one shown in Fig. 5 is for each roller 2゜13.1.
4.15 The force 5 rotates in the same direction, which has the disadvantage that it cannot eliminate the uneven thickness of the varnish caused by the notch in the blanket cylinder 2. In other words, immediately after the applicator roller 13 passes through the notch of the blanket cylinder 2, the film thickness of the varnish on the applicator roller 13 is large, and the thickness of the varnish on the applicator roller 13 is large immediately after the applicator roller 13 passes through the notch of the blanket cylinder 2, and the thickness of the varnish on the applicator roller 13 is large immediately after the applicator roller 13 passes through the notch of the blanket cylinder 1. The thickness of the varnish on the roller 13 is thinner than that during the first rotation, and therefore the thickness of the varnish on the printed matter can be uneven. Even if a so-called small window is provided by cutting out a part of the rubber cylinder 2, similar varnish unevenness will occur on this part.

The roller shown in FIG. 6 is different from the one shown in FIG. 5 in that the rotational directions of the welding roller 24 and the base roller 28 are reversed. This is because unevenness in the varnish film thickness due to the notches and small windows in the blanket cylinder 2 causes the varnish flowing back on the coating roller 13 to be forced onto the storage tray 16, and does not affect the thickness of the varnish supplied to the coating roller 13. It was devised as a trap. However, there are many fireflies of the return varnish on the application roller 13, and the N roller 13 and the roller 2
Although this can be expected if varnish builds up at the contact point with 4, in normal cases S
As a result, the thickness of the returning varnish on the forming roller 13 becomes uneven, and this also affects the thickness of the supplied varnish on the forming roller 13! There is a drawback that it is difficult to avoid unevenness in the varnish film thickness by applying #.

The one shown in FIG. 7 does not have a wetting roller as compared to the ones in FIGS. 3
The rotation direction of rollers 33 and 34 is the same as that shown in FIG. The difference is that a varnish tray 37 is provided below. This is different from the one shown in FIGS.
This is eliminated by a varnish pool that forms on the abutting portion of 34. However, since the form roller 33 rotates at the same speed as the blanket cylinder 2, even if the linear pressure between the metering roller 34 and the form roller 33 is increased and the circumferential speed of the metering roller 34 is decreased, the nip between both rollers will be reduced. Due to its high viscosity, the varnish that passes through the gap inevitably grows in size. Therefore, there is a drawback that even if it is desired to reduce the thickness of the coating film of varnish X, it cannot be made below a certain limit. Furthermore, in this case, the adjusting roller 34 is often a roller called a mesh roller or an anilox roller, but in this case, there is also a drawback that the lower limit of the adjustable varnish coating thickness inevitably increases.

Inventive Power S Problems to be Solved The purpose of the present invention is to eliminate the drawbacks of the conventional varnish applicator as described above, and to improve the thickness of the varnish coating on the surface of printed paper using the notches and small windows of the blanket cylinder. Without causing unevenness,
Another object of the present invention is to provide a varnish coating device that allows easy determination of the thickness of the varnish coating and has a wide adjustment range.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention arranges a blanket cylinder, a form roller, a welding roller, and a metering roller to face each other in this order, and the blanket cylinder and the rollers are arranged in the same direction. The applicator roller and the welding roller are rotated in opposite directions, the applicator roller and the metering roller are rotated in the same direction, and the varnish is supplied from above to the contact area between the applicator roller and the welding roller. This is a characteristic feature.

Function: In the above-mentioned device, part of the supplied varnish passes between the application roller and the wetting roller and is carried to the varnish supply side of the application roller, and the other part passes through the application roller and the application roller. and the metering roller. The latter varnish merges with the former varnish and is transferred to the blanket cylinder by a post-applying roller, and the varnish on the blanket cylinder is applied onto the printing paper that passes between the impression cylinder and the rubber.

Embodiments In the first to third embodiments of the present invention shown in FIGS. 1 to 4, the same reference numerals will be used to refer to the same parts as in the conventional system, and mainly different parts will be explained.

In the first embodiment shown in FIGS. 1 and 2, 3 is a rubber cylinder 2.
A forming roller 4 rotates in the same direction in opposition to the forming roller 3, a welding roller 4 rotates in the opposite direction in opposition to the wetting roller 3, and a metering roller 5 rotates in the same direction in opposition to the upper part of the welding roller 4. , 6 indicates a supply member disposed above the contact portion of both rollers 3 and 4 to supply varnish to the same group, and 7 indicates a varnish receiving tray disposed below the contact portion of both rollers 3 and 4. . The application roller 3 is at the same speed as the rubber cylinder 2,
The welding roller 4 and the metering roller 5 are each driven by a drive member (not shown) so that the circumferential speed can be changed independently, and the linear pressure between the wetting roller 4 and the metering roller 5 is not shown. It can be adjusted using an adjustment mechanism. The rollers 3.5 are preferably made of rubber or resin, and the roller 4 is preferably made of metal.

In such a device, a part C (not shown) of the varnish B supplied from the supply member 6 passes between the applicator roller 3 and the wetting roller 4, and the other part C (not shown) passes between the application roller 3 and the wetting roller 4 and the metering roller 4. After passing between the rollers 5, these varnishes O and D merge at the lower part of the contact portion of both rollers 3 and 4 to form varnish A, which is carried to the supply side of the applicator roller 3 and transferred to the blanket cylinder 2. It will be done. In this case, the amount of varnish Bo is greater than the amount of varnish, so that varnish remains at the upper part of the contact portion of both rollers 3 and 4.

In this case, the varnish accumulates in the upper part of the contact area of the side rollers 3 and 4, so that unevenness in the film thickness of the varnish on the application roller 3 passes through this accumulation area due to the notch or small window of the blanket cylinder 2. The film of varnish on the supply side of the applicator roller 3 is eliminated by
The thickness is not influenced by the rubber cylinder 2.

Further, the amount of varnish C in the above case is small because the rotation directions of both rollers 3 and 4 are opposite, so that when this varnish C is transferred to the blanket cylinder 2, the required varnish is Since it is insufficient than the amount of AO, the shortage is covered by varnish D.
This will be supplemented by If you increase or decrease t of varnish D according to the needs of the varnisher, the required amount will always be met.

The amount of varnish D can be increased or decreased by adjusting the pressure resistance and speed '48 of both rollers 4.5. In other words, the applicator roller 3 must have the same speed as the blanket cylinder 2, but the circumferential speeds of both rollers 4 and 5 can be changed.
When it is desired to reduce the amount of varnish D, the peripheral speed thereof is reduced, and when it is desired to increase the amount of varnish DO, the linear pressure of both rollers 4 and 5 may be reduced.

The tray 7 receives the varnish that falls from the end of the roller if there is an excess of varnish.

The second and third embodiments shown in FIGS. 3 and 4 differ from the first embodiment only in the position of the metering rollers 51, 51, and are otherwise completely the same, so a description thereof will be omitted.

Effects of the Invention The present invention is as described above, and includes a rubber cylinder, a forming roller,
The welding roller and the metering roller are sequentially brought into contact with each other, and the blanket cylinder and the applicator roller are rotated in the same direction, and the welding roller and the metering roller are rotated in the same direction, and the applicator roller and the metering roller are rotated in opposite directions. Since the varnish is supplied above the contact area of the blanket cylinder, unevenness in the film thickness of the varnish on the coating layer caused by the notches and/or windows on the blanket cylinder is caused by the difference between the coating roller and the welding roller. Increases and decreases in the film thickness of the varnish on the printing material, which is dissolved by the varnish remaining on the contacting portions of the printing material and transferred from the applicator roller to the blanket cylinder, can be easily controlled by adjusting the linear pressure, circumferential speed, etc. of the spreading roller or metering roller. It has the advantage of being able to perform operations over a wide range and reliably.

[Brief explanation of drawings]

Fig. 1 is a front view of the first embodiment of the present invention, Fig. 2 is a perspective view of the same as above, Figs. 3 and 4 are front views of the second and third embodiments of the invention, respectively, and Figs. FIG. 7 is a front view of three typical examples of conventional varnish applicators of the same type as the present invention. l...Pressure cylinder 2...Blank cylinder 3...Applying roller 4...I roller 5, 5',
5'... Measuring roller 6... Varnish supply member Figure 5 Shoulder of M6 Figure 7

Claims (1)

[Claims] 1. A blanket cylinder that rotates with printing paper attached to its circumferential surface, a forming roller that rotates in the same direction in opposition to this blanket cylinder, a welding roller that rotates in the opposite direction in opposition to this forming roller, and A printed matter varnish application device comprising: a metering roller that rotates in the same direction in opposition to a welding roller; and a supply member that supplies varnish from above to a portion where the application roller and the welding roller come into contact.