JPH02504495A - A method for manufacturing a gravure plate that can change depth or depth and area - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] A method for manufacturing a gravure plate that can change the depth or the depth and area. metal or plastic gravure plates that can vary depth, depth, and area. Regarding manufacturing methods. This manufacturing method uses light-sensitive photoresist paint during chemical decomposition. using photosensitive insulating paint during electrolysis or cleaning with high-energy irradiation. Use a protective coating that can be extracted and/or selectively removed, or Use lacquer.

In order to explain the fundamental purpose of this invention, the most important Of the important methods, I will first briefly describe the following.

a) In known conventional methods, a midtone positive is used as starting material, e.g. Transfer to screened pigmented paper or pigmented film. After developing in warm water (during this time Unexposed gelatin areas are washed out. ), on a gravure cylinder or gravure plate The remaining dispersive relief is deeply etched with an etching bath (e.g. ferric oxide). do. Dots in the shadow area (aOt) (which contain no or almost no gelatin) I don't have any. ) are thereby etched first, and the brighter areas (here Geraci The etching medium forms a somewhat dispersive barrier between the etching medium and the metal of the plate. )in is suppressed in time and intensity so that proportional depth steps are achieved. Ru.

This process for dots with theoretically the same size that occupies the maximum required cell wall spacing It is called ``variable depth'' which has a dot area of .

This traditional gravure manufacturing method provides the very best print quality. But the same Sometimes the highest requirements are required in plate production.

advantage: Large ink volumes in shadow areas and large markings even in light values Very good printability due to the printing surface.

This manufacturing method overcomes the inherent problems inherent in print carriers, e.g. pores (so-called "missing dots"), or non-absorbable carriers ( The problem of ink transfer in the case of aluminum (eg aluminum) is best overcome.

Disadvantage: Plate manufacturing must strictly adhere to optical standards (e.g. Do.

3 to 1.65) is difficult and It's expensive.

It is always difficult to obtain film materials of suitable quality on the market.

Since a mid-tone positive is used before etching, there is no possibility of a final proof. stomach.

As a result of the use of dispersive etched relief, plate making requires less sensitization, manipulation and copying. consumption during etching process and between development and etching. To explain the strictness with which it is applied, for example, even a deviation of 1μ in the depth of the color tone of light is also makes the edition useless.

b) Offset-gravure processing when developing from "traditional" etching production methods , a screen offset positive is used instead of a midtone positive, so Provides simplification. On difficult print carriers (e.g. porous paper surfaces) Except for the manufacture of plates with variable depth and area to produce good quality printing That means.

Simple film products made of film materials of great importance & easily screenable A reproduction studio equipped with a system for color separation of final proofs. Oh.

Possibility of final proof before etching.

Greater tolerance for etching deviations in light tones.

Disadvantages: The need for cylinder manufacturing using dispersed gelatin relief as well as traditional methods .

Printability problems with print carriers with porous surfaces or non-absorbent carriers Printability problems due to the small contact surface of small dots in the case of rear c) by means of a scanner for reading the image information in the connected engraving unit; The engraving of electronic gravure cylinders has always become more important. This center The letters are engraved directly into the copper surface of the plate with a diamond needle. This relatively new The new manufacturing method uses porous or non-absorbent print carriers (in this case, Ink transfer becomes difficult. ), good printability can be obtained. .

Advantages: At the preliminary stage, e-gravure can complete the e-page and create a complete image. It can be further developed before manufacturing the lumeless cylinder.

Disadvantages: As a result of the diamond needle, the cell plate is pyramid-shaped, so that the individual cells limited ink volume.

Too small because the transfer surface is too small or in too bright colors Due to the large volume, “missing dots” or difficult to print onto print carriers may occur. Difficulty in link transfer.

For fine text and lines, due to the zigzag shape of the engraving lines, Similarly, there should be only a mediocre print quality caused by the diamond-shaped hole of the diamond needle.

Relatively slow production of cylinders, and therefore a disadvantage factor. For example, about 0.3~ Only one engraving product with an engraving surface area of 0.41 manufactured per engraving head and per engraving time.

The steel structure of the plate must be particularly stiff and very flat.

d) In plate gravure using a laser beam, a plastic surface is used instead of an ordinary copper surface. Requires paint. This occurs when metals are irradiated with high energy. Performing laser gravure on metal to avoid reflections and crater formation This is because it becomes difficult.

Advantages: Preliminary electronic work such as electronic page finishing is required before filmless cylinder production. stages are possible.

Fast manufacturing speed.

Disadvantages: Plastic paints of very specific composition are required as bed pellets.

High investment.

e) Electron beam gravure is described here only for completeness.

f) The manufacture of halftone gravure plates will be discussed here last. This points out several points This is because this manufacturing method is most similar to the manufacturing method of the present invention described below.

For this type of gravure plate production, gravure screens (e.g. cross lines), and fills made of large and small dots that match the tonal values of the image. The lume is reproduced on a copper cylinder coated with a reproduction lacquer (Tpolymer). Photographed. Coating is preferably carried out with a spray gun or dipping method. Paint thickness is 1 to about 3μ! It is. Copying is preferably done using an all-round copier be done. During this time, the painted cylinder with the positive film in contact is inserted into the light slot. The image information on the film is transferred onto the acid-resistant copying paint. Ru. After development, transparent screen lines and non-printing transparent film areas are removed from the cylinder. The dots harden and accumulate on the metal surface, but the (black) dots on the film are not developed. During the next etching step or electrolysis step, the copper surface is washed out and drawn into the copper surface. be included.

Uses midtone screen positives (instead of midtone positives in traditional methods) As a result, it is also possible to use complex (instead of dispersive gelatin relief) This method of producing midtones is widely available for non-“yes/no” reproduction paints. used. It is especially used in the packaging industry.

Despite this, the overetching of small tods results in a small print compared to the surface. Printability often deteriorates. This allows you to use the "tone scale" for mid-tones when printing out. This leads to the well-known difficulty that the length is too short. In other cases, this is The result is that the surfaces of small gravure cells of very small diameter come into contact. Iku As already mentioned in connection with some other manufacturing methods, this This leads to printing problems in the case of astringent materials (eg aluminum).

Advantages: Fast, easy and relatively economical manufacturing method Disadvantages: Quality issue with certain print carriers.

For large area copies, including all repeat copies (with some exceptions) The necessity of working with film, which has corresponding problems with regard to dust and other environmental influences. guide the subject.

As a result of its application, this manufacturing method can be used as an electronic page finishing system or It cannot be incorporated even in the production of lumeless cylinders.

The purpose of the present invention is to simplify and improve the manufacturing method currently used for producing gravure plates. be.

The gravure production method (generally defined primarily in this way) The cell depth variability or depth and area variability is achieved by at least one photoresist. dots, printing lacquers, insulating or protective coating elements (this is called "dot core") Ru. ), at least in the area of gravure intended for lighter tonal levels. Dots of photoresists, insulating or protective coatings (printing lacquers) in the area Defined as something that is affected by overlaying or introducing into the target area .

Advantageous further developments and improvements of the idea and manufacture of the invention are defined in the subclaims. (However, these cannot be directly resolved by a person skilled in the art.)Moreover, the following , will be explained in more detail.

As can be seen from the above-mentioned description of the known manufacturing methods of a), b), C), d) and ``), It is desirable to obtain depth steps in the labia cell, but at the same time to the level of light tones. It is also desirable to make the contact surface area of this cell as large as possible even in The present invention is based on this recognition.

The present invention avoids or eliminates hindering factors in currently known gravure plate manufacturing methods. This will solve this problem. In particular, it shows the following advantages:

All midtone positives with exactly the density values of the densitometer mentioned above (not required) .

Dispersible etching relief of pigmented paper or film materials that is difficult to control can be done without.

This production method is as fast as the known economical method of gravure printing. I can. That is, the benefit is good.

The tolerances regarding copper hardness and flatness of the steel structure of the gravure plate may be small.

The aforementioned difficult plastic coating of the bed plate is not required.

Requires large area repeat copy film process with handling problems and contamination problems stomach.

When implementing a method, it may be necessary to incorporate a preliminary electronic step or a filmless process. It is possible to

Examples of the manufacturing method of the present invention will be described with reference to the following figures.

FIG. 1 shows a conventional method of manufacturing plates of variable depth or variable depth and area.

Figure 2 shows the so-called "under-etching" in the conventional production of gravure plates. This is a phenomenon that is feared.

Figure 3 compares the first basic type produced by the method of the invention with the conventional method. Shown.

Figure 4 (A/B) shows the production of the gravure cell of the present invention by the half tone method. A comparison is shown with the production of a gravure cell.

FIG. 5 shows an example of the method of the invention using a dot core in the center of each print cell. shows. Note that the gray scale assumes a case of intermediate tone screening.

Figure 6 shows the print cell volume for mid-tone grayscale; Another pure midtone version is shown. In addition, this method preferably uses the method of the present invention during its manufacture. It was there.

FIG. 8 shows a preferred embodiment of the method for forming the different depths. This aspect In this case, the printing result first roughly corresponds to the "traditional" gravure described above in (a).

Figure 9 shows the cylinder at a relatively slow rotational speed of -, e.g. with a passage width of 2u, e.g. The deviation in direction is indicated by an outline sketch.

Figure 1O shows how to create a record in an engraving unit by using an optoelectronic system. This shows the deviation of the laser beam.

Figure 11 shows the deflection of an engraving laser beam using a polygonal mirror. vinegar.

Corresponding parts and cells (indentations, paint, etc.) in individual drawings are marked with the same reference symbol. mentioned.

The reference symbols used have the following meanings:

10: Photoresist paint, protective paint (in the case of plastic version, it may be washed away) / to be dissolved. ), or insulating paint for electrolysis of insulating paint.

11: Plate metal paint (usually steel) or plastic. This form can be cylindrical or plate It is a shape.

12: High-energy beam (laser, electronic beam) of well-developed or resist insulation or protective coating removed by

13 Exposed metal or plastic surfaces after removal of resist, insulation, or protective coatings .

14: In the case of etched or electrolyzed gravure cells or plastic plates indicates washed or lysed cells.

15: Due to the lateral effect of the decomposition medium, the retention of each section of the plate is caused by the dot core. effect.

16: Dot generator (RI) on the film master or in case of filmless process "Normal" dot in P).

17 and 18: Film master or dots during RIP in case of filmless process Gravure cell (17) with tone scale dependent multiplicity of tocoa (18).

19: “Normal” dots printed on print carrier for midtone process to.

20: Printed dots of the same tone value using the dot core method of the present invention.

2. Marks to be engraved shown in various dimensions in FIGS. 9 to 11 printing cylinder.

22: Laser beam generator shown in FIGS. 10 and 11.

23: Deflection mirror with as much total deflection as possible.

24 Nilight Beam (Laser) Modinilator.

25: Optoelectronic deflection unit.

26: Laser beam focusing optical system.

A polygonal mirror that can be rotated by 272 operations.

28: Model of the laser beam from the laser generator 22 to the surface of the cylinder 21 Formal beam passage.

29: Engraving shown in a highly enlarged partial view of the right side of Figure 9 200 cells engraved by a laser beam within a track width a.

The first thing that can be seen from Figure 1 is the well-known erosion effect, which is usually considered a "defect". It is. This works not only in the radial direction but also in the vertical direction (depth). and this Chemical etching, electroerosion, and similar plastic plate cleaning or Significant in dissolution.

In chemical etching, this effect (see Figure 2) can be seen, for example, in under-etching. It is called ``Ning''. If the etching process does not finish in a reasonable time, the final The layers lead to the terrifying situation of ``wall collapse.'' As a result, during the printing process, Appropriate doctoring of the gravure version is no longer possible.

The above-mentioned effect on lateral (variable area) etching is similar to that of non-dispersive paints (which , serve simply as protection from the chemical effects of the etching solution, or may act as an electrical Upon disassembly, it simply acts as an insulating coating. ) and/or used in a specific controlled manner in the manufacturing method of the present invention to achieve volume reduction. It will be done. This provides a much better reserve for ink replacement during printing.

As an example, first of all, a clear mid-tone dot (Fig. 3) is made by regular etching. (left side), and the second one using the dot-core process of the present invention (Figure 3, right side) Let's consider. The volume reduction of the cell (right side of Figure 3) corresponds to the cell surface. Enables expansion of the product. Therefore, the ink volume of the first midtone etching (e.g. For example, the reserve requirements for ink transport are considerably improved without increasing the amount of water (e.g., FIG. 1). So On the contrary, the ink volume is considerably reduced.

In Figures 4(A) and 4(B), on the left side is a normal midtone cell and its printed surface. (4th (B) fixed side), on the right side there are printed cells according to the method of the invention and correspondingly enlarged I will explain the printed surface again. Also, in the latter case, is the ink volume of each cell the same? , or even decreasing.

Figure 5 shows gravure grayscale with midtone screening . In each case, one dot core of equal size is placed in the center of each print cell. It is set in.

As is clear from the cross-sectional view in Figure 5(B), the effect of the dot core is greater than that of the corresponding cell sensor. Each case is different depending on the size. Cell cores that “remain” in small cells (right side) (in which case a reduction in cell volume is desirable), the effect of the dot core is This results in a relatively large percentage of the cell volume, but for “sufficient” cells (on the left) However, the overall reduction in cell volume is not large. pieces in grayscale The degree of volume change in each cell is determined by stretching of the dot core, changes in geometry, Grouping to form larger units or “strategic” placement by those skilled in the art can be influenced by

Figure 6 shows this variation in cell volume in the case of a mid-tone gray scale. This is an example. The larger cell (on the left) has no dots at all. This means that there This is because volume is required and desired. Large cell surface results in sufficient ink transfer transmission is carried out reliably. The intermediate size dots (Figure 6, center) indicate the created set. Grouping of several dot cores to obtain a corresponding volume reduction of the core. It is. The smallest dot (on the right) contains only a single dot core.

This dot core occupies a significant amount of space over the entire diameter of the cell. suitable glue The requirements can be improved by choosing Depending on the printing requirements to be achieved, especially the material to be printed also has a gray value with respect to ink volume ratio. It becomes possible to adapt the scale accurately. This means that the non-conformity of the present invention is always constitutes a significant advantage.

FIG. 7 shows a preferred dot core distribution of the present invention with another pure midtone plate. Show application. The method shown, however, also applies to different area and depth versions, as well as It can also be used to manufacture objects of various depths.

As is clear from the plan view in Figure 7 (A), the dot core is located at the edge of the largest cell. located only at Here, at the center between the two cell walls, 'Underetching' and reduction of the cell walls can normally occur and is a common occurrence. Occurs frequently. This is indicated by the dashed line in the cross-sectional view of FIG. 7(B). The solid line is It clearly shows a reduction in the underetching effect.

FIG. 7(C) shows the cell table after etching when using the dot core process of the present invention. Shows the geometry of the surface. On the other hand, Fig. 7 (D) shows a conventional type of normal etching. The corresponding geometry after modification is shown.

A variation of the embodiment of the invention in FIG. 8 shows a method for manufacturing cylinders with varying depths, This produces a print similar to traditional gravure. of all tonal values to a considerable extent. Cell surfaces of the same size in the step, e.g. 100 x 100 μl, are Depending on the cell volume, there may be more or less large dot cores or multiple dots corresponding to each gray value. Equipped with a dot core. These dot cores can be grouped in various ways and and/or different sizes, for example within the range of 5 μm in diameter and 1 to 10 μl. good.

Resolution 2400d, p, i, (dots/inch; approx. 1000 dots/c11) Currently commercially available laser exposure systems meet the requirements of the process of the present invention. I can do it. For example, with a conventional gravure screen of 70 lines/cyt, A side length of the cell surface of about 100 μm is obtained.

Due to the dot core effect of the present invention, the volume can be reduced for all gradations of the gray scale. In order to This is possible. Figure 8 (A) shows a copy of the plate manufactured by this method. Indicates pea. On the other hand, Fig. 8(B) shows the cross section of the etched or electrolyzed plate. show. And the dot core effect of reducing depth and volume that can be achieved with the present invention. The results are obvious.

The basic system design for carrying out the manufacturing method of the present invention is shown in Figures 9 to 11. A brief explanation will be given below with reference to this. In addition, laser exposure or laser pre-enclosure will be used here. Graping or electron beam exposure or engraving is used.

Traditional manufacturing methods by laser or electron beam engraving (this manufacturing method In each case, one entire cell does not have one or more dot cores of the present invention. naturally exposed or engraved. ), almost no uke can be accepted. In order to achieve even production speeds, relatively very high rotational speeds are applied to the cylinder 21. must be given to.

On the other hand, with respect to variants of the aspects of the invention described herein, a plurality of cells may e.g. With a rack width a='lxx, the circumferential torque of the cylinder 21 due to the very fast lateral deflection Each rack is exposed or engraved. As a result, in each case, e.g. For example, 200 dots with dot elements with a shoulder diameter of 10μ are applied in the longitudinal direction of the cylinder. Positioned by rack. In this way, the rotational speed of the series is considerably reduced. A spiral process is carried out in the converter 21 (this is clearly shown on the left side of FIG. 9). . ).

The deviation width in the lateral direction (that is, the axial direction of the cylinder 21) is the rotational speed obtained from it. speed can be chosen to roughly correspond to that of this engraving machine. Ru. This is an electronically controlled engraving machine that already exists using & makes it possible to convert to laser operation by attaching a laser device .

FIG. 10 shows the arrangement of the first basic apparatus for laser exposure.

This uses an electron deflection unit 25. This unit can be used for example as an (improved) block. Bragg cell or other known optoelectronic diversion unit. controlled by a variable frequency generator in the form of a

In a variation of the embodiment of FIG. 11, the laser beam 28 is directed laterally, ie perpendicular to the drawing. direction, and the polygonal rotating mirror 27 (the rotational speed of which depends on the rotation of the cylinder 21). It is in sync with the rolling speed. ) in the axial direction of the cylinder 21.

In conclusion, the following outlines the particular advantages of the production method of the present invention compared to currently known production methods. I will briefly explain the comparison.

Dot-core manufacturing method vs. “traditional” gravure manufacturing method: Manufacturing method in Figure 8: Omission of dispersion of etching paint (pigmented paper or film).

Possibility of incorporating preliminary electronic steps up to the production of filmless cylinders.

Variant: Manufacturing method shown in Figures 5 and 6: Omission of dispersibility of etching paint (pigmented paper or film).

Possibility of incorporating preliminary electronic steps up to the production of filmless cylinders.

Dot core manufacturing method vs. electronic gravure: Manufacturing method shown in Figures 5 and 6: The manufacturing speed is many times higher.

Obvious ink volume increase.

Copper hardness and structure are non-limiting.

The quality of fine lines/characters is outstanding.

There are no problems with the wear of the stylus or its setting.

Dot core manufacturing method vs. laser gravure on plastic paint: Figures 5 and 5 Manufacturing method shown in Figure 6: The plate is a well-known conventional copper plate, ie, ordinary chrome dipped.

Dot-core manufacturing method vs. mid-tone manufacturing method: Figure 7 (and Figures 5 and 6 are also possible) ) manufacturing method: as a result of plates with variable depth or area, printability is improved. Improving the way things are done.

Expansion of the surface area of small dots (for example, see the right side of Figure 4) and the Improved ink transfer.

Possibility of incorporating preliminary electronic steps up to filmless cylinder production; film repeating process to obtain large format copy film. Avoidance of P.

FIG.1 FIG.3 FIG.5 FIo, 1 FIG.9 international search report IT1wwmIm11&Kokoro/EP88100496 International Investigation Report

Claims (17)

[Claims] 1. Using photosensitive photoresist paint during chemical decomposition or photosensitive during electrolysis Selectively removed using insulating paint or washed out and/or with high energy radiation variable depth of the gravure cells (14, 17), or Variability in depth and area is achieved by at least one photoresist, printing lacquer, or The protective paint element, i.e. the "dot core" (18), is applied in at least a lighter tone tone. Photoresist or protective coating in the area of the gravure form intended for the bell (Printing lacquer paint) By adding or placing on the dot area of (10) Metal or brush stick of variable depth or variable depth and area affected A method for producing gravure plates. 2. In gravure plates with sufficient depth, no dot core is provided at all, and the same dot As the tone scale increases to lighter tones in the individual dot cores and/or dot cores with correspondingly increased multiplicity. 2. The manufacturing method according to claim 1, wherein the dots are provided in bright colors. 3. Claim 1 or 2, wherein the dot core is designed as a round dot with a diameter of 5 to 100 μm. 2. The manufacturing method described in 2. 4. The dot core has an oval line, polygon, star shape, or collotype grain design, Claim 1 or 2, wherein they are distributed symmetrically or randomly over the area of each gravure cell. 2. The manufacturing method described in 2. 5. Large ink-receiving volume to strengthen the cell walls in the edge area of the dots 5. According to any one of claims 1 to 4, having a particularly distributed arrangement for cells having Manufacturing method described. 6. If the dot core is using a film, it can be removed by contact or by a glass screen. additional programming of the film scanner's dot generator in the case of sentence scanners. 2. The method according to claim 1, wherein the method is carried out by a ram. 7. In the case of metal plates, this is provided with a light-sensitive, acid-resistant printing lacquer (10); The screened image created by the dot core is copied onto this and then fully exposed. According to any one of claims 1 to 6, the plate is etched to a required depth with an etching medium. manufacturing method. 8. In the case of metal plates, a photosensitive copying lacquer is provided that is resistant to subsequent galvanic erosion. Any one of claims 1 to 6, wherein the plate obtained and sufficiently exposed to light is deeply etched by an electrolytic process. The manufacturing method described in Crab. 9. The photosensitive plastic paint serves as a plate master or base. The manufacturing method according to any one of claims 1 to 6, wherein the method is coated on a plate as a plate. 10. The plastic paint on the plate or cylinder is used as a printing plate, which is then The coating is provided with a photoremovable protective layer that is resistant to developing, washing, or dissolving processes. 7. The manufacturing method according to any one of claims 1 to 6. 11. A copying machine with a laser beam or a light emitting diode matrix The manufacturing method according to claim 1, which is used for copying a via plate. 12. (a) Use a non-photosensitive protective or insulating paint so that the dot information on the plate is coating with a laser beam or other high-energy beam without attacking the metallic surface. 6. The composition according to claim 1, wherein the composition is made by locally removing the material. Production method. 13. a laser beam or other high energy beam is excited under clock control; set transversely to the direction of plate movement, i.e. axially in the case of printing cylinders 13. Manufacture according to claim 12, characterized in that it is laterally deflected at high speed over a track width (a). Method. 14. The lateral deviation is caused by a dot with a diameter of 10 μm on the deviation track width a = approximately 2 mm. 14. The manufacturing method according to claim 13, wherein the manufacturing method is carried out using about 200 pieces. 15. Ceramic paint where the protective or insulating paint remains on the plate during the subsequent printing process The manufacturing method according to claim 12, comprising: 16. An etching-resistant or galvanizing-resistant protective coating with image information is applied electrostatically. After the protective coating is cured, the dots are either deeply etched or electrolytically etched. The manufacturing method according to claim 1 or 2. 17. An etching-resistant or galvanizing-resistant protective coating with image information is It is painted on a gravure plate using the photo method, where free zones corresponding to dots are created. 3. The etchant according to claim 1 or 2, which is then deeply etched by chemical etching or electrical erosion. Manufacturing method described.