JPS6020743B2 - Manufacturing method for gravure printing plates - Google Patents

Description

[Detailed description of the invention] There are two types of gravure printing methods, the conventional gravure method and the silk gravure method. The conventional gravure method uses a gravure positive film as an original plate, which continuously changes the density. The size of the silk dots is kept constant, and the amount of ink film is determined by the depth and depth of the plate to express the shade of ink, but with this method, when it is transferred to carbon tissue, developed, and subjected to corrosion treatment, There are many unstable factors in making the depth of the plate, and the corrosion depth varies, making it difficult to make the desired printing plate.

On the other hand, the net gravure method is a method in which shading is expressed by the size of silk dots, but this method has the drawback of insufficient reproducibility of density tone.

The present invention relates to a method for producing a gravure printing plate that eliminates the above-mentioned drawbacks using a silk positive film for flat plates or letterpress printing.

0 By the way, the net positive film used in planography and letterpress printing differs in form from the original plate used in the well-known silk gravure method, and gravure printing plates are prepared using net positive films for planography or letterpress printing. However, in the first step of the present invention, a net positive film for lithography or letterpress printing is combined with an ordinary lithographic film and printed on a commercially available contact printer. A negative film is produced by vacuum contact and exposure.

Next, in the second step, two diffusion films were inserted between this silk negative chip film and a commercially available 0 unexposed continuous tone film, and exposed in vacuum contact using the contact printer, and a blurred net positive film was Next, as a third step, this blurred net positive film is baked on a sensidized carbon tissue, and then, as a fourth step, a screen printing material made of a translucent material according to the invention of the present inventor is manufactured. A special gravure contact screen is made by attaching the screen to a continuous tone film, exposing it, and developing it to create a blurred positive screen film, and then attaching it to a lithium-type reversal film, exposing it, and developing it to a density of 2.9 degrees. After phosphorization, a gravure printing plate is prepared according to a well-known gravure plate making method, and gravure printing is performed using this plate. The present invention
As described above, a squirrel-type film is closely attached to a silk positive film for planography or letterpress and exposed to light to obtain a silk negative film, and then a diffusion sheet, for example, translucent paper such as tracing vapor or parchment paper, is attached to the mesh negative film. By inserting the film between the film and the continuous tone film and exposing it to light, the silk dots of the negative film can be made into a positive film with sharp blurring by using a diffusion sheet.

Next, this is adhered to the sensidized carbon tissue and baked, and then a screen printing screen (for example, a nylon silk screen) made of a translucent material according to the inventor's invention is attached to a continuous tone film. Close contact, exposure, development and no blurring with positive screen film,
This is closely attached to a squirrel-type reversal film, exposed, developed, and a special gravure contact screen with a density of about 2.5 is glued on.

This step corresponds to the step of printing a conventionally used gravure screen onto the blurred halftone dots of the blurred mesh positive chip film that was applied to the carbon tissue in the above step, but the above-mentioned method used in the present invention A contact screen for gravure can be made by covering a silk positive with a screen and having cells.

This is transferred to a cylinder for gravure printing, developed, and eroded to create a printing plate for gravure printing.

The above-mentioned first and third steps are rigid in nature, combining the characteristics of conventional gravure, which is determined by the depth of the ink receiving cells and the ink adhesion area ratio, and net gravure, which is similar to lithography or letterpress printing. A printing plate was obtained, and since the special gravure contact screen invented by the inventor was used in the fourth step, the silk spots that appeared on this printing plate were
Since cells are formed, when printing using these cells, it is possible to prevent leakage from occurring in printed matter. As described above, the special gravure contact screen used in the present invention has a density of 2.9 base degrees, so it has the advantage that the exposure operation is easy when printing carbon tissue.

Claims (1)

[Claims] 1. A halftone positive film for planography or letterpress printing is closely attached to an ordinary lithographic film and exposed to produce a halftone negative film, and a tracing paper or the like is placed between this and a commercially available unexposed continuous tone film. Insert translucent paper as a diffusion film, adhere to it, and expose to light to create a positive blurred film.
This is baked onto sensidized carbon fiber,
Furthermore, a method for producing a gravure printing plate, which comprises making a special gravure contact screen, baking the screen onto the carbon tissue, and then producing a gravure printing plate according to a well-known gravure plate-making method. The special gravure contact screen is made by contacting a screen printing screen made of a translucent material to a continuous tone film, exposing it to light, developing it to form a blurred positive screen film, and then contacting it to a lithographic reversal film, exposing it to light, and developing it. A method for producing a gravure printing plate, characterized in that it is developed to a density of about 2.5.