JPH0516303U - Fountain solution for a printing machine that also functions as a paper plate - Google Patents

Abstract

(57) [Summary] [Purpose] A paper plate / printing machine that is convenient to use for printing with a paper plate while making it possible to use it as a dampening water device for PS plates as much as possible. The purpose is to obtain a dampening water device. [Structure] A dampening water circulation device (11) for the paper plate is provided in the middle of the pipes (9) and (10) connecting the dampening water circulation device (8) for the PS plate and the water boat (4). Plumbing of (1
2) and (14) are connected via three-way valves (13) and (15).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an offset printing machine that can be used as both a PS plate made of an aluminum substrate and a paper plate made of a paper substrate as a printing plate, and more particularly to a dampening water device for the paper plate.

[0002]

[Background of the invention]

 Offset printing uses the property that ink and fountain solution repel each other, and ink and fountain solution are applied to a printing plate that has lipophilic image areas and hydrophilic non-image areas. Is supplied to the blanket cylinder to transfer the image area to which ink is selectively attached, and this image area is further transferred to the paper.The printing plate is chemically treated. PS plates based on aluminum are often used.

However, recently, the required level as a printed matter is not so strict, and in printing small lots, the base material is water-resistant processed paper and plate making is performed by electrophotography, so-called direct printing. Paper plates have come to be used, and this paper plate has the advantage of low plate material cost and plate making cost.

By the way, the printing by the paper plate has a temporary and convenient character that is performed between the so-called full-scale printing by the PS plate. There is a strong demand to use the dampening water device as it is, instead of installing a dampening water device.

However, since the dampening water for the PS plate and the dampening water for the paper plate have completely different chemical compositions, the dampening water circulation for feeding and circulating the dampening water to the watercraft. The device is not compatible. For printing with a printing plate and a paper plate, drain the PS plate dampening water from the dampening water circulation device for the PS plate, wash the inside of the device, and then add a new dampening water for the paper plate to dampen it. The use of sluice circulation equipment is very wasteful and time consuming.

[0006]

[Problems to be solved by the device]

 The present invention has been made in view of the above problems, and provides an improved dampening water device for a printing press, which aims to be used together with a dampening water device for a PS plate as much as possible. It is intended to be a dampening water device that is convenient to use for printing on a paper plate while being used for various purposes.

[0007]

[Means for Solving the Problems]

 For this purpose, the present invention connects the dampening water circulation device for the PS plate and the piping from the dampening water circulation device for the paper plate through a three-way valve in the middle of the pipe. It was done.

[0008]

[Action]

 As a result, printing with the PS plate and the paper plate can be performed by a simple operation of switching the 3-way valve.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic explanatory view showing an embodiment of a dampening water device of a paper plate / printing machine according to the present invention.

In the drawings, only one printing unit of a sheet-fed offset printing machine is shown, but of course the device of the present invention is equally applicable to a large number of printing units for multicolor printing. Further, in the drawings, only the plate cylinder (1) and the blanket cylinder (2) are shown, and the other impression cylinders, transport cylinders and inking devices are omitted for simplification.

A printing plate (3), which is a PS plate or a paper plate, is wound around the plate cylinder (1), and ink is applied to the printing plate (3) from an inking device (not shown) and a dampening solution of the present invention. A fountain solution having different properties for PS plate or paper plate is supplied from the device, and the image corresponding to the image area is transferred to the blanket cylinder (2) according to the principle of the offset printing described above. This image is printed on the paper between the impression cylinder (not shown).

The dampening water supplied to the printing plate (3) is temporarily stored in the water boat (4). A water source roller (5) whose speed is controlled by a motor is immersed in this watercraft (4), and the dampening water pumped up by the rotation of the water source roller (5) is fed by a metering roller (5). The amount of passage is adjusted by a roller nip between the plate 6) and the roller nip, and then it is attached to the printing plate (3) through the swimsuit roller (7).

A dampening water circulation device (8) is arranged at a side end of the printing machine in order to feed dampening water for the PS plate to the water boat (4). The dampening water circulation device (8) for the PS plate is a comparatively large unit, and internally has a cooling, filtration, alcohol concentration adjusting mechanism and the like. The dampening water circulation device (8) sends the dampening water to the water boat (4) through the pipe (9) and returns the dampening water from the water boat (4) through the pipe (10). ing.

In the dampening water device of the present invention, the dampening water circulating device (11) for the paper plate is provided separately from the dampening water circulating device (8) for the PS plate. The dampening water circulation device (11) for the paper plate is smaller in function and scale than the dampening water circulation device (8) for the PS plate, and has functions such as cooling. Does not have to. However, this dampening water circulating device (11) also sends out dampening water for the paper plate to the water boat (4) and returns it to the dampening water circulation device (8) for the PS plate. Is the same as.

The pipe (12) for sending the dampening water for the paper plate from the dampening water circulation device (11) to the water boat (4) includes the pipe (9) for the PS plate and the three-way valve. The pipe (14) for connecting the dampening water for the paper plate from the water boat (4) to the dampening water circulation device (11) is connected through the pipe (14) for the PS plate. (10) and the three-way valve (15).

The operation of the proposed device is clear. That is, when printing with the PS plate, the dampening water sent from the dampening water circulation device (8) is supplied to the water boat (4) through the pipe (9), and also the pipe (10). It is returned to the dampening water circulation device (8). Then, when printing with a paper plate, the dampening water for the paper plate is dampened by switching the 3-way valves (13) and (15) to the piping (12) and (14) sides, respectively. It is sent from the water circulation device (11) to the water boat (4) and is returned from the water boat (4) to the dampening water circulation device (11).

[0017]

[Effect of the device]

 According to the device of the present invention, there is an effect that printing with the PS plate and the paper plate can be performed very easily by a simple operation of switching the three-way valve.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of a dampening water device of a paper plate / printing machine according to the present invention.

[Explanation of symbols]

 1 plate cylinder 3 printing plate 4 water boat 8,11 dampening water circulation device 9,10,12,14 piping 13,15 3-way valve

Claims (1)

[Scope of utility model registration request] 1. A dampening water circulation device (11) for a paper plate is provided in the middle of piping (9), (10) connecting a dampening water circulation device (8) for a PS plate and a water boat (4). The pipes (12) and (14) from () are connected via three-way valves (13) and (15), respectively.