JPS633952A - Multicolor flat-bed proof press - Google Patents

Abstract

PURPOSE:To prevent a slur by sinking printing paper by letting air out of the gap between a surface plate and the printing paper, by providing a paper press roller at the position contacted with the printing paper of the stand in front of a blanket roller on and after a second color in a printing advance direction. CONSTITUTION:The printing of a first color by a first blanket roller 2 is performed in such a state that printing paper 6 is settled on a printing surface plate. However, at the time of the printing of a second color by a second blanket roller 3, the printing paper 6 is in a slightly levitated state. Then, a paper press roller 7 is arranged between the second blanket roller 3 and the first blanket roller 2 on this side of said roller 3 and the printing paper levitated after the printing of the first color is pressed from above to perform the printing of the second color by the second blanket roller 3. Therefore, a slur phenomenon can be suppressed by sinking the printing paper 6 by the paper press roller 7 and the generation of spoilage due to a printing mistake is reduced and printing quality can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention is a method of placing printing paper on a surface plate and
In a multicolor hand proofing printing machine in which two or more blanket rollers contact and rotate on the printing paper on this surface plate to print, the blanket rollers for the second and subsequent colors and the previous plate/throat roller. This relates to the paper pressing roller installed between the two.

(Conventional technology and problems to be solved) Conventionally, a problem that occurred when printing with a multicolor hand proofing printing machine was that when printing was performed with a blanket roller, the ink and blanket transferred onto the printing paper. The printing paper is pulled up by the peeling phenomenon of the ink remaining on the roller, and air is filled between the printing paper and the surface plate. Therefore, it takes a long time for the printing paper to expel this air due to its own weight.

However, when performing multicolor printing, the distance between the blanket rollers is generally narrow.

Therefore, the next blanket roller will print before the printing paper has completely fallen. -Then, the printing paper first comes into contact with the next blanket roller, and then is sandwiched between that blanket roller and the surface plate. At this time, the printing paper and the plate/gutter roller rub slightly. This rubbing appears as a phenomenon called slur on the printing paper.

In other words, the printed image is rubbed in the printing direction.

Demand for inexpensive printing paper has recently increased, and many of these inexpensive printing papers are lightweight. - In general, lightweight printing paper tends to cause the above-mentioned paper floating to be large. Therefore, slur phenomena occur frequently due to this background.

(Object of the Invention) The present invention solves the above conventional drawbacks, and when the plunket rollers of the second and subsequent colors print, the same way as when the plunket rollers of the first color print, To prevent the printing paper from floating off the surface plate, we provide a multicolor hand alignment printing machine that has a mechanism that allows the air between the printing paper and the surface plate to be exhausted and the printing paper to be quiet. death,
The purpose of using this printing machine is to prevent slurs.

(Summary of the Invention) The present invention is a multi-color hand proofing printing machine, after printing with the previous plunket roller, prints between the second and subsequent plunket rollers and the one previous blanking roller. Proof printing is performed using a multicolor hand proofing printing machine that can print while holding down the floating printing paper with an installed paper holding roller.

(Embodiments of the Invention) Next, the present invention will be described in more detail with reference to the drawings, taking a two-color proofing printing machine as an example. Figure 2 shows
1 is an example of a conventional two-color proofing press roller system. The only rollers that come into contact with the printing paper (6) on the printing platen (1) are the first blanket roller (2) and the second blanket roller (3). The first blanket roller (2) receives the ink of the printed image from the platen (4), and likewise the second blanket roller (3) from the platen (5). The first and second blanket rollers then print the ink of the print image onto the printing paper (6). Now, printing of the first color by the first planner roller (+) is performed with the printing paper (6) settled on the printing surface plate (1).However,
When printing the second color using the second blanket roller (second blanket roller), the printing paper (6) is in a slightly floating state.

FIG. 3 is an explanatory diagram of the printing paper (6) in a slightly floating state. Then, the second blanket roller (3) prints the second color on the part where the printing paper (6) remains floating, so the print image of the second color printed on the printing paper (6) is , a slur phenomenon occurs in which the image appears to be rubbed in the printing direction.

Next, the plunket roller system of the two-color proofing press will be explained with reference to FIG. What is different from the conventional one is the paper pressing roller (7). This paper press roller (7
) is lowered only on the printing platen (1). In other words, the first
After printing the first color with the blanket roller (2), the printing paper (6) that has floated up is pressed from above with the paper pressing roller (7), and then the second color is printed with the second blanket roller (3). That is what it is.

This paper pressing roller (7) is non-greasy and does not have any effect even if it comes into contact with the wet printed image on the printing paper. Examples of materials that can be used include a stone surface similar to marble treated with mucilage acid, and a roller whose surface is treated with silicone. Below are some examples of the ingredients of this lithograph stone (.

Calcium carbonate 95% Iron oxide 0.1% Aluminum oxide 0.3% Silicic acid 0.1% Magnesium carbonate 1.6% Water 0.2% Others
2.7% The structural formula of mucilage acid is as follows.

(Margin below) COOII CO11 □ II OCIl II OC11 11COH CO011 (Young fruit of the invention) As described above, if the multicolor hand proofing printing machine of the present invention is used, the front of the blanket roller for the second and subsequent colors can be By using a paper pressing roller to make the paper smooth, it becomes possible to suppress the slur phenomenon, which reduces the occurrence of waste paper due to printing errors and improves printing quality.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the roller system of the present invention. FIG. 2 is an explanatory diagram of a conventional roller system. FIG. 3 is an explanatory diagram of floating of printing paper. (1) Printing surface plate (2) First plunge roller 3) Second blanket roller (4) Plate plate (5) Plate plate (6) Printing paper (7) Paper pressing roller claimant Toppan Printing Co., Ltd. Representative: Kazuo Suzuki

Claims (2)

[Claims] (1) In a multicolor proofing printing machine in which a blanket roll for each color is attached to a stand in order to print two or more colors, the second and subsequent color blanket rollers touch the printing paper on the stand in front of the printing progress direction. A multicolor flatbed proofing printing machine characterized by having a paper press roller in position. (2) The paper holding roller of the multicolor flatbed proofing printing machine is
The multicolor flatbed proofing printing machine according to claim 1, characterized in that it is oil-insensitive.