JPH0415490Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printing gloss improving device for a sheet-fed printing press.

[Conventional technology]

In order to improve the gloss of the printed surface in intaglio or lithographic printing, which performs thick printing, Japanese Patent Laid-Open No. 57-1980 developed a device that applied pressure using an impression cylinder with an oil-repellent layer on the entire surface.
It has been proposed as shown in Publication No. 205194. In this gloss improvement device, a thick printing material passes printing between a plate cylinder and a first impression cylinder, and then is pressed by a second impression cylinder.

[Problem that the invention attempts to solve]

The conventional gloss improvement device described above requires a new pressing device consisting of an impression cylinder and a receiving cylinder and a separate printing material after printing in order to flatten the irregularities on the ink surface which are the image areas in thick printing. This system is equipped with a conveyance device, and there is a problem in that it requires the addition of a conveyance device.

This invention is an attempt to solve the above-mentioned problem, and in all cane leaf planographic printing machines, not just those for thick printing, between the blanket cylinder and the impression cylinder, after printing is completed, the impression cylinder and the discharge cylinder The gloss of the printing material is improved by pressing the printing material while being transported by a press cylinder and a receiving cylinder, which have a mechanism for transporting the printing material on the circumferential surface provided between the printing material and the printing material. An ink-repellent layer is formed on the surface of this pressure cylinder, a mechanism for conveying the printing material is provided on the circumferential surface of both cylinders, and the bearing of the pressure cylinder is devised so that the pressing force can be adjusted.

[Means for solving problems]

For this reason, the present invention has a sheet-fed lithographic printing machine, in which an impression cylinder having an ink-repellent layer formed on its outer periphery and its receiving cylinder are disposed facing each other between a final impression cylinder and a discharge cylinder, and the peripheral surface of each cylinder is It is equipped with a conveyance mechanism for delivering and conveying the printing material, and is used as a means to solve the problem.

[Operation] The printing material is delivered and conveyed from the impression cylinder to the pressing cylinder and the receiving cylinder by a conveyance mechanism, and during that time, the printing material is pressed by bringing the pressing cylinder having the ink-repellent layer into contact with the receiving cylinder. The unevenness on the ink surface, which is the image area of printed matter, is flattened and the gloss of the printed material is improved.

〔Example〕

The present invention will now be described with reference to the most preferred embodiment shown in FIG.

In the figure, numerals 1, 2, 3, 4, and 9 are a plate cylinder, a blanket cylinder, an impression cylinder, a calendar unit, and a paper discharge cylinder, respectively. The calendar unit 4 is composed of a press cylinder 5 and a receiving cylinder 8, each of which has a removable cover 6 having an ink-repellent layer on its outer periphery. As the ink repellent layer on the covering 6, for example, a silicone resin layer having a flat surface is used. The pressing force of this calender unit 4 can be adjusted by an eccentric bush which is a bearing part of the press cylinder 5. Reference numerals 7 and 7' designate grippers located on the outer peripheral sides of the pressing cylinder 5 and receiving cylinder 8 of the calender unit 4, respectively. 10 is a chain, and 11 is a substrate to be printed. The arrows indicate the direction in which the respective cylinders and printed products are transported.

Next, the operation will be explained. Ink transferred from the plate cylinder 1 to the blanket cylinder 2 is transferred to the surface of the printing material between the blanket cylinder 2 and the impression cylinder 3. The shape of the ink surface immediately after printing on the surface of the printing material may be incompletely leveled depending on the viscosity of the ink, etc., and a ripple-like uneven state is formed, causing a lack of gloss. The leading edge of this printed matter is gripped by the gripper 7 of the press cylinder 5 of the calendar unit 4,
Next, when it is gripped by the gripper 7' of the receiving barrel 8,
As shown in FIG. 1, pressure is applied to the surface of the printing material by the ink repellent layer 6 on the pressure cylinder 5 of the calendar unit 4 and the receiving cylinder 8, and the uneven state on the ink surface, which is the printing area, is reduced. Flattened. The pressure required to flatten the uneven portions on the ink surface is variably adjusted by adjusting the eccentric shaft of the press cylinder 5 depending on the type of ink, film thickness, target gloss area, etc. The printing material 11, which has been pressed by the calender unit 4 and whose gloss has been improved, is conveyed by the chain 10 from the receiving cylinder of the calender device to the chain gripper of the paper discharge cylinder.

Here, when we tested the gloss improvement effect under the conditions of printing speed: 3 m/sec and pressing pressure: 10 kg/cm ink repellent layer: silicone resin, we found that in the conventional case without pressing, the gloss value (60°) was 60. In contrast, when pressed under the above conditions as in the present invention, the gloss value (60°) was 72. Note that the pressing force is preferably 5 to 40 kg/cm.

[Effect of idea]

In this way, the present invention can be applied to sheet-fed lithographic printing machines.
A press cylinder and its receiving cylinder are inserted between the impression cylinder and the paper discharge cylinder, and an ink-repellent layer is attached to the outer periphery of the press cylinder.
Since pressure is applied to the printing material between both cylinders, the gloss of the printing material can be improved.
Furthermore, since a smooth ink film is formed, this is also effective in preventing back-side transfer when stacked.

[Brief explanation of the drawing]

FIG. 1 is an explanatory side view showing a schematic configuration of an embodiment of the present invention. 3... Impression cylinder, 5... Pressing cylinder, 6... Covering, 8... Receiving cylinder, 9... Paper discharge cylinder.

Claims (1)

[Scope of utility model registration request] A press cylinder with an ink-repellent layer formed on the outer periphery and its receiving cylinder are arranged facing each other between the final impression cylinder and the discharge cylinder of a sheet-fed lithographic printing machine, and the printing material is delivered and conveyed on the circumferential surface of each cylinder. A printing gloss improving device characterized by being equipped with a conveying mechanism that