JP5804791B2 - Method for producing printing film - Google Patents

Description

  The present invention relates to a method for producing a printed film, and more specifically, a printing unit surface formed by multicolor printing is arranged on one surface of a long plastic film along the longitudinal direction of the film. The present invention relates to a method for producing a printed film.

  Conventionally, for the purpose of content display, advertising, and improvement of product value, the outer surface of metal cans (label cans) such as seamless cans and welded cans has been made with a transparent resin film designed by gravure printing. It is stuck. Such a film is generally formed by continuously forming a printing unit surface by multicolor printing on one surface of a long plastic film, and the printed long film is appropriately coated with an adhesive. It is wound and stored on a roller, and is unwound from the roller at the time of use, and is wound and fixed on a metal can while being cut for each printing unit surface.

  By the way, in recent years, printing has become more multicolored due to diversification of design, etc., the number of colors of ink used in gravure printing has increased, and the number of printing according to the number of colors is required. Causes unevenness in the thickness of the printed layer, causing an unexpected inconvenience. For example, a long printed film used for a label can as described above may generate a linear protrusion called a bone due to the uneven thickness described above when wound on a roller. is there. In particular, recently, the thickness of the film has been reduced from the standpoint of cost reduction and the tension at the time of winding around the roller has been set from the viewpoint of increasing the production speed, and the occurrence of bone is frequently observed. It is becoming. Such bone formation induces peeling of the ink layer and peeling of the adhesive (blocking) when the printed film wound around the roller is unwound from the roller, and eventually wrinkles when wound around the can body. Will cause poor appearance.

As a means for correcting the thickness unevenness of the printing layer, for example, Patent Document 1 discloses a colorless and transparent so as to have a thickness equivalent to the printing ink layer on a plain portion other than the printing portion of the printed film base. It has been proposed to apply a resin.
Patent Document 2 proposes that in a gravure printing method for printing a pattern on a plastic film, a transparent ink or the like is applied to a non-pattern part so that the film thickness of the ink or the like is uniform over the entire surface. Has been.

Japanese Patent Publication No.58-52814 JP 2009-255436 A

  As proposed in Patent Documents 1 and 2, a method of applying an ink or resin to a thin portion to make the entire thickness uniform has been conventionally employed. However, such means are effective when the print design is simple and the number of inks used is small, but it is practically impossible when the number of inks is large and a complicated print design is applied. It can be said. That is, for example, when a print design is formed with only two colors of white ink and black ink, and the black ink layer is formed on the white ink layer, the portion other than the black ink layer is formed. It is only necessary to apply a resin or ink that adjusts the thickness (hereinafter referred to as correction ink), but as the number of inks increases and the print design becomes more complicated, it becomes difficult to define a portion to which correction ink is applied. End up. Even if a portion to which correction ink is applied can be defined, such a portion has a complicated shape, and it is extremely difficult to accurately apply correction ink to the portion. In addition, the above-described linear convex portions called bones are also induced when the portion to which the correction ink is applied is slightly shifted.

  As described above, in multicolor printing using a large number of color inks, it is extremely difficult to adjust the thickness of the formed printing layer uniformly, and the effectiveness is poor. Therefore, depending on the experience and intuition of engineers, the location where bones are likely to occur is selected according to the printing design, and correction ink is applied to this part. Because of this, it is necessary to test print the film over thousands of meters in length to check for the occurrence of bone, and in some cases, the very long film must be discarded, and the bone is generated In some cases, the plate (bone plate) for applying the correction ink had to be corrected, and a great deal of cost and time were spent to prevent bone.

  Accordingly, an object of the present invention is a long printing film having a printing layer by multicolor printing on one surface, and linear protrusions resulting from uneven thickness of the printing layer when wound on a roller An object of the present invention is to provide a method for producing a printed film in which occurrence of (bone) is effectively prevented.

According to the present invention, there is provided a printing film in which a printing unit surface formed by a multicolor printing layer composed of an ink layer of each color is arranged on one surface of a long plastic film along the longitudinal direction of the film. In the manufacturing method,
Based on the plate-making data produced for each color ink, a processed image in which the thickness of the multicolor printing layer is binarized is formed on the printing unit surface, and the multicolor printing layer is formed based on the processed image. Create basic bone data for forming a correction ink layer on the part where the thickness of
Based on the plate-making data for each ink of each color and basic bone data, the total of the ink layers of each color for each constant width of 2.0 mm or less set in the direction perpendicular to the printing direction on the printing unit surface. Calculate the total ink area by adding the area and the area of the correction ink layer, and from the distribution of the calculated total ink area in the width direction, the total ink area is the total area of the ink layer of each color in any part of the width direction. The bone plate data is created by correcting the bone plate basic data of the correction ink so as to be 60 to 110% of the maximum value of
Printing with an ink for each color ink using a plate roller for each color ink produced based on the plate making data, and printing with a correction ink using a bone plate roller produced with the bone plate data, There is provided a method for producing a printed film, which is continuously applied to one surface of the long plastic film and wound on a roller.

In the manufacturing method of the present invention, after the printing unit surface is formed by printing using the plate roller and printing by the bone plate roller, an adhesive is applied on the printing unit surface. It is preferable to be wound around a roller.
The printed film manufactured as described above is used, for example, by being cut for each printing unit surface and wound around a can body so that the printing unit surface becomes an inner surface.

  In the present invention, bone plate basic data for forming a correction ink layer is created based on binarization processing data for the thickness of a multicolor printing layer formed based on predetermined plate making data. The bone basic data is further corrected. That is, the stencil basic data is produced based on data obtained by binarizing the thickness of the multicolor printing layer, and the stencil roller produced based on this data includes cells (recesses). The shape or structure of (3) is quite simple and can be easily produced, but it is a fairly rough correction, and the formation of the correction ink layer based on the basic data of the stencil makes it difficult to wind the printing film on a roller. The generation of bone cannot be reliably prevented, and for this purpose, this basic bone data is further corrected.

In other words, in the present invention, the basic bone data created based on the thickness of the multicolor printing layer is corrected by the ink application area. Specifically, the application area of all the inks applied to the film (that is, the total value of the application areas of each ink) is within a certain range at any part in the width direction perpendicular to the printing direction. The basic stencil data is corrected so that the correction ink is further superimposed on the portion having a small total ink area, and the stencil data is created.
In this way, the total ink application area (total amount of each color ink and the correction ink amount) for each width direction applied to the long film is adjusted within a certain range. It is possible to effectively prevent the occurrence of bone caused by the variation in the thickness of the printing ink layer when the printing film is wound with a roller.

  Moreover, the adjustment of the total ink area for each width direction applied to the long film may be performed so that the maximum value of the total area of the ink layer of each color is 60 to 110% of this reference value. The degree of freedom is extremely high, and high accuracy such as uniform thickness of the multicolor printing layer is not required. Furthermore, since the adjustment of the total ink area can be performed while ignoring the local thickness of the multicolor printing layer, it can be easily performed even if the printing design has a complicated shape. In addition, the cells (recesses) formed in the plate can also have a simple shape.

  Therefore, in the present invention, the cost for producing the bone plate for forming the correction ink layer can be easily performed at a low cost, and moreover, a complicated design is applied by multicolor printing without relying on experience and intuition. Even in this case, a long printing form can be wound around the roller without generating bone.

The schematic diagram which shows an example of the cross-sectional structure in the printing unit surface of the multicolor printing film in which the thickness adjustment by correction | amendment ink is not performed. The schematic plan view of the printing film of FIG. The figure which shows the state which wound up the multicolor printing film of FIG. 1 on the roller. The schematic diagram which shows an example of the cross-sectional structure in the printing unit surface of the multicolor printing film by which thickness adjustment by the correction | amendment ink was performed according to this invention. The figure which shows the state which wound up the printing film of FIG. 3 on the roller. Print design formed by overlaying each color plate making data. An image obtained by binarizing the print design of FIG. Graph showing the distribution in the width direction of the total ink area The figure which shows the image by the bone plate data obtained by correct | amending bone plate basic data.

  1 and 2, when a print design is formed on one side of a film by multicolor printing, a long film 1 is used, which is fed from a roller (not shown), and the film 1 By continuously performing multicolor printing by gravure printing on one of the surfaces, the printing unit surfaces (designated as 3 as a whole) on which the printing design has been performed are continuously arranged along the film feeding direction. After completion of such printing, an adhesive is applied onto the printing unit surface 3, and the formed printing film is wound around a roller. The printing unit surfaces 3 formed by gravure printing may be formed in a single row or may be formed in a plurality of rows. FIG. 2 shows an example in which the printing unit surfaces are formed in two rows.

  As shown in FIG. 1, the printing unit surface 3 formed on the long film 1 has a form in which the printing design is observed from the front surface A side of the film 1, and the back surface B of the film 1. On the side, a multicolor printing layer 5 indicated by 5 as a whole is formed. That is, the multi-color printing layer 5 is formed from ink layers 5a to 5f of each color, for example, color ink layers 5a, 5b, 5c, and 5d such as black, purple, red, and yellow are formed, and further, metallic A bright ink layer 5e for expressing a feeling and a white ink layer 5f serving as a background are formed, and a desired print design is formed by these ink layers.

  However, in such a printing unit surface, depending on the printing design, the color development on the surface A side differs depending on the position. For example, in some portions, there is a portion where all of the ink layers 5a to 5f overlap, There is also a portion where only the white ink layer 5f exists. For this reason, unevenness is formed on the surface of the printing unit surface 3 due to uneven thickness of the multicolor printing ink layer 5. When a printed film (indicated by 10 as a whole) on which such irregularities are formed is wound around a roller, as shown in FIG. 3, linear wrinkles 13 called bones (hereinafter simply referred to as bones) Often occurs. When the printing film 10 in which such bones 13 are generated is wound around the outer surface of the body portion of the metal can to exhibit its decorating properties, peeling of the multicolor printing layer 5 or dropping off of the adhesive occurs. Therefore, the commercial value of the metal can is significantly reduced due to poor appearance. In order to prevent the occurrence of such bones 13, it is necessary to adjust the thickness of the multicolor printing layer 5 by applying correction ink in accordance with the present invention.

  That is, in FIG. 4 which shows an example of the cross-sectional structure in the printing unit surface 3, in this printing film 10, the multicolor printing layer 5 is formed by the ink layers 5a-5f of each color similarly to the printing film 10 of FIG. The multi-color printing layer 5 shows the same print design as the printing film 10 of FIG. 1, but in FIG. 4, a correction ink layer 15 is formed. 5 is adjusted, and the unevenness on the printing unit surface 3 is alleviated, thereby preventing the generation of bone 13. For example, as shown in FIG. 5, in the printing film 10 in which the correction ink layer 15 is formed according to the present invention and the thickness of the multicolor printing layer 5 is adjusted, the commercial value decreases when the printing film 10 is wound around a roller. Bone 13 leading to is not generated.

  Since the correction ink layer 15 as described above does not form a print design, ink of a color that does not appear on the surface A side where the print design is observed and does not affect the print design (for example, white or milky white) ). For example, in the example of FIG. 4, the correction ink layer 15 is provided between the glitter ink layer 5e and the white ink layer 5f, and is hidden from view by the glitter ink layer 5e. Of course, the present invention is not limited to this example. For example, the correction ink layer 15 can be provided on the white ink layer 5f as long as the color tone of the white ink is not impaired.

  In the present invention, the correction ink layer 15 as described above has a printing design separately from the plate roller for each color for forming the ink layers 5a to 5f for each color (that is, the plate roller for forming the printing design). A stencil roller for forming is produced based on the stencil data, and the stencil roller is used to apply correction ink at a predetermined position and a predetermined timing.

The preparation of bone plate data is performed by the following process.
(A) Overlay of each color plate making data (screen display of print design image)
(B) Binarization processing of printed design image (reversal as appropriate)
(C) Preparation of bone plate basic data (d) Calculation of width direction distribution of total ink area from each color plate making data and bone plate basic data (e) Correction of bone plate basic data by calculation of width direction distribution of total ink area (Bone plate data production)

That is, appropriate image processing software based on plate-making data (prepared for each color) for forming ink layers of each color (for example, ink layers 5a to 5f in FIG. 4) according to the target printing design. Is used to superimpose these plate making data and display the print design to be displayed on the print unit surface on the computer monitor (process (a)).
An example of the print design displayed on the monitor at this time is shown in FIG.

The image showing the printing design displayed above is binarized with respect to the thickness of the multicolor printing layer 5 calculated from the plate-making data (process (b)).
By this binarization processing, a portion thicker than a predetermined threshold is displayed in black and a portion thin in thickness is displayed in white. This binarization processing is performed to determine a portion to which correction ink is applied. Therefore, in consideration of the subsequent processing, the binarized image is inverted. This inverted image is shown in FIG.

Based on the image shown in FIG. 7, basic bone data is created (process (c)).
For example, data such as cell coordinates and depth of the stencil roller and printing timing by the stencil are created so that the correction ink is applied in a certain amount to the portion shown in black in FIG.

  Note that this data is not exact and is corrected in the following process, so in areas where white background (part where correction ink is not applied) or black background (part where correction ink is applied) is scattered. It is also possible to perform correction for converting this into a black background or a white background. By such correction, the cell shape and the like of the bone plate roller can be made extremely simple.

  It is also possible to apply gradation to the boundary between the black background and the white background. Since the correction ink is applied or not applied at the boundary, the clearer the boundary, the more the difference in the thickness of the printed layer is, the reverse is the presence or absence of the correction ink layer due to printing misalignment. Since the generation of bone is promoted, such inconvenience can be surely prevented by applying gradation. (In the part where the gradation is applied, the depth of the cell formed on the stencil roller gradually changes.)

The basic bone data produced as described above merely adjusts the thickness of the multicolor printing layer 5 roughly. Therefore, the bone plate for further correcting this data to form the correction ink layer 15 is used. You need to create data.
In the present invention, this correction is performed under the condition that the total ink area is a sum of the area of the ink layer of each color (application area of each ink) and the area of the correction ink layer (application area of the correction ink based on the basic bone data). (Processes (d) and (e)).

That is, based on the plate-making data for each color ink that has been initially produced and the bone plate basic data created above, for the printing unit surface 3, for each constant width w in the direction perpendicular to the printing direction, The total ink area is calculated by adding the total area of the ink layers of each color (for example, ink layers 5a to 5f in FIG. 4) and the area of the correction ink layer based on the basic stencil data, and the distribution in the width direction of the total ink area is obtained. (Process (d)).
FIG. 8 is a graph showing the distribution in the width direction of the total ink area.
That is, when a long film on which a printing unit surface is formed is wound around a roller, the printing unit surface does not continue to overlap at exactly the same position, so the distribution of the ink area in the winding direction (printing direction) is: It is the distribution of the ink area in the width direction perpendicular to the winding direction (printing direction) that has little influence on the occurrence of bone and has an influence on the occurrence of bone. For this reason, in this invention, the graph which shows the width direction distribution of all the ink areas is calculated, and a correction | amendment ink layer is adjusted based on this graph.

In FIG. 8, a region indicated by X (outlined portion) is a region indicating the total area of each color ink layer, and this region X indicates the area of the ink when the thickness adjustment with the correction ink is not performed.
Moreover, the area | region (hatching part) shown by Y is the area of the correction | amendment ink layer formed by the bone plate basic data produced based on the binarization process mentioned above.

  In the present invention, based on the distribution in the width direction of the total ink area in this figure, the basic bone data is corrected so that correction ink is further superimposed on the portion where the total ink area is small to obtain bone plate data (process (e)). .

That is, in a portion where the total area of the ink layer of each color protrudes and is large, when the long print film 10 is wound around the roller, the portion overlaps dozens, and as a result, the bone 13 is easily generated. In the present invention, in addition to the setting of the correction ink layer based on the binarization process described above (that is, correction based on the thickness of the multicolor printing layer 5), the correction is performed by the total application area of all the inks added with the correction ink. Since the correction ink layer is corrected, it is possible to effectively prevent the bone 13 from being generated on the long print film 10 wound up by the roller.
For example, without creating the bone basic data based on the above-described binarization processing, the distribution of the total area of each color ink is directly calculated, and the total area of all the inks falls within a certain range from this distribution. In addition, when the correction ink layer 15 is set, the thickness adjustment in consideration of the color density of each color is not performed at all, so that the generation of the bone 13 cannot be effectively suppressed.

In the present invention, the correction based on the ink application area as described above is based on the maximum value of the total area of each color ink layer, and the total ink area is 60 to 110% of the reference value in any part in the width direction. In particular, a portion to be overcoated with the correction ink is set so as to be 70% or more and less than 100%. For example, in FIG. 8, a dotted line α is a line indicating the reference value, and a region indicated by Z (solid black portion) indicates the area of the correction ink that is further overcoated by such correction.
That is, when the amount of the correction ink to be overcoated is small and there are portions where the total ink area is smaller than the above range, it is difficult to effectively prevent the generation of the bone 13, and the total ink area When the correction ink is overcoated so as to be larger than the above range, the ink is wasted and only increases the cost.

  Furthermore, the correction of the ink application area as described above does not mean that the entire ink area is uniform over the entire width direction of the printing unit surface, but there is a considerable degree of freedom. Such a plate can be easily produced.

In calculating the width direction distribution of the total ink area for the printing unit surface, as can be understood from FIG. 8, the width of the printing unit surface (the direction perpendicular to the printing direction or the film flow direction) is reduced. The total ink area is calculated for each constant width w by division, and this w is usually preferably set to a size of about 1.0 to 2.0 mm. If the width w is too large, the area distribution becomes considerably rough, and the area where the total ink area is extremely small or large is locally hidden by averaging, effectively preventing the occurrence of bone 13. May be difficult to do. Even if the width w is set to be smaller than necessary, the correction work is only troublesome. Therefore, it is preferable to set the width w within the above range, obtain the total ink area for each width w, and create a graph of the distribution in the width direction.
Further, in the above graph of the distribution in the width direction, w is further subdivided (for example, about w = 0.2 mm) in a portion where the amount of ink area on which the correction ink is overcoated is small, and the total ink area is calculated and partially It is also possible to create a width direction distribution graph that is subdivided into two. By such partial subdivision, the application portion of the correction ink can be set more finely and the occurrence of bone can be prevented more reliably.

An image based on bone plate data obtained by correcting the bone plate basic data as described above is shown in FIG. 9, for example.
In FIG. 9, an area 30 (hatched portion) indicates a portion to which the correction ink is applied based on the bone plate basic data prepared based on the above-described binarization process, and a black solid region 31 indicates the bone plate A portion where correction ink is overcoated based on bone plate data obtained by correcting basic data is shown.
That is, a stencil roller for applying correction ink based on the stencil data is produced so that such an image is formed. Note that, in the portion where the region 30 and the region 31 overlap, the cell depth of the corresponding portion may be set deep.

In the present invention, a plate roller for each color ink is manufactured based on the pre-prepared data for each color ink, and a bone plate roller for applying correction ink from the above-described bone plate data is laser-produced. A long printed film 10 having a correction ink layer 15 is obtained by performing multicolor printing by applying ink and drying using these rollers for each ink in a predetermined order. It is done.
Note that, as described above, the printing order is performed such that a predetermined printing design is shown and the correction ink layer 15 is not observed from the outside. In general, when the correction ink is applied to the multi-color printing layer 5 having the layer structure as shown in FIG. 1, the correction ink is formed lastly by applying the correction ink. It is common.

After the multicolor printing, an adhesive is applied on the multicolor printing layer 5 including the correction ink layer, and the printing unit surface 3 is formed in a plurality of rows as shown in FIG. Are separated into each row by a slitter and wound around a roller for each row.
In the printing film 10 wound around the roller in this way, generation of bones 13 is effectively prevented by adjusting the thickness of the multicolor printing layer 5 made by the above-described means.

  By the way, for the print design formed on the printing unit surface with a length of 17 cm in the printing direction and a length of 10 cm in the width direction, the stencil basic data is created from the processing data by the binarization processing and inversion described above Based on the distribution in the width direction of all the inks calculated every 1.5 mm, the bone plate basic data is corrected so that the distribution shown in FIG. 8 is obtained, and bone plate data is created. As the correction ink was applied, 8-color multicolor printing was performed over 6000 m on a polyethylene terephthalate film with a thickness of 12 μm and wound around a roller at a speed of 120 m / min, but no bone was generated. Has been confirmed.

The long printing film obtained as described above is cut for each printing unit surface, for example, the above-described printing unit surface 3 side (the side on which the multicolor printing layer 5 is formed and the adhesive is applied). ) Is adhered to the outer surface of the body of a metal can such as a seamless can or a welded can, and then the finish varnish is formed on the surface side of the film (the surface on which the multicolor printing layer 5 is not formed). Next, after finishing the finish varnish and curing the adhesive by oven heating or the like (or irradiation with ultraviolet rays, electron beam, etc.), neck-in processing, flange processing, etc. are performed, and a predetermined label can It will be transported to the seller.
Further, the printed film can be used for forming a bag-like container (pouch), for example, in addition to being applied to a metal can.

  In addition, in the above-described printing film, the long film on which printing is performed is not particularly limited as long as printing is possible, and is formed of a known transparent thermoplastic resin, For example, low density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene or random of α-olefins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene Olefin resins such as block copolymers and cyclic olefin copolymers; ethylene / vinyl copolymer resins such as ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, ethylene / vinyl chloride copolymer Polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene copolymer Styrenic resins such as coalescence; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymer, polymethyl acrylate, polymethyl methacrylate; nylon 6, nylon 6-6, nylon 6 10, amide resins such as nylon 11 and nylon 12; polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polycarbonates; polyphenylene oxide; biodegradable resins such as polylactic acid; Good. In general, it is excellent in transparency and at the same time has good heat resistance to heat treatment (drying of ink and finishing varnish, curing of adhesive, etc.) performed when producing this printed film. In this respect, polyester such as polyethylene terephthalate is preferable.

  Moreover, since the thickness of the long film 1 to which printing is performed is not particularly limited and is set to an appropriate thickness according to the application, it cannot be specified unconditionally, but when pasting on a general beverage can The thickness is about 8 to 30 μm. Such a film may be appropriately uniaxially or biaxially stretched.

  Furthermore, various inks used for multicolor printing are known per se, and pigments or dyes of a predetermined color are dissolved or dispersed in a solvent together with a binder according to the printing design and required functions. A known solvent-type paint is preferably used.

  Furthermore, the adhesive is used for sticking and fixing the printed film to, for example, the outer surface of a metal can. For example, a thermosetting, ultraviolet curable, or electron beam curable transparent polyester resin is used. Acrylic resin, epoxy resin, polyurethane resin, etc. are used. These are used by applying a coating liquid dispersed or dissolved in a predetermined solvent on the multicolored printing layer 5 of the printing film and drying it. After the film is attached to the outer surface of a metal can or the like, it functions as an adhesive by curing by heating, ultraviolet irradiation, electron beam irradiation, or the like.

  In the present invention, the present invention is not limited to the embodiment in which the ink layers 5a to 5f of the respective colors are formed in the order shown in FIG. 1 or FIG. 4, and for example, this position can be set in reverse. In this case, the print design is observed from the back surface B side without the film 1, and therefore the correction ink layer 15 is formed on the film 1, for example, so as to cover the other. An ink layer is formed, and the adhesive is formed on the reverse surface of the film 1 (surface B on the side where the multicolor printing layer 5 is not formed), and further, a finished varnish after being fixed to a metal can etc. Is applied onto the multicolor printing layer 5.

  According to the present invention, it is possible to effectively prevent the occurrence of bone even when a thin film is used as a long film and a long film printed at a high speed is taken up. Can be reduced.

  In addition, for example, in the case of forming a complicated design using seven or more kinds of inks excluding correction inks, it is not necessary to adjust the thickness of the multicolored printing layer with high accuracy, and simple. In addition to the thickness adjustment by the binarization process, it is possible to prevent the occurrence of bone with only a very easy correction of adjusting the coating area of all ink within a certain range, and to shorten the time required for manufacturing Furthermore, it is easy to produce a plate roller for correction ink (bone plate roller) for preventing bones.

  In addition, when creating bone plate data that applies correction ink to thin parts using only the thickness data of the multicolor printing layer calculated by accumulating the plate data of each color, the maximum of the multicolor printing layer Since all other parts are corrected (applying correction ink) based on the thickness, the correction ink is wasted, and the occurrence of bone is promoted even if a slight printing misalignment occurs. However, in the present invention, since the application area amount is adjusted based on the data adjusted by the binarization process (and inversion), the correction ink is selectively applied to the portion where the bone is easily generated. The occurrence of bone can be effectively prevented even when the correction ink is not applied wastefully and a slight printing misalignment occurs.

1: long film 3: printing unit surface 5: multicolor printing layer 5a to 5f: ink layer of each color 10: printing film 13: bone 15: correction ink layer

Claims (3)

In a method for producing a printing film in which printing unit surfaces formed by a multicolor printing layer composed of an ink layer of each color are arranged on one surface of a long plastic film along the longitudinal direction of the film,
Based on the plate-making data produced for each color ink, a processed image in which the thickness of the multicolor printing layer is binarized is formed on the printing unit surface, and the multicolor printing layer is formed based on the processed image. Create basic bone data for forming a correction ink layer on the part where the thickness of
Based on the plate-making data for each ink of each color and basic bone data, the total of the ink layers of each color for each constant width of 2.0 mm or less set in the direction perpendicular to the printing direction on the printing unit surface. Calculate the total ink area by adding the area and the area of the correction ink layer, and from the distribution of the calculated total ink area in the width direction, the total ink area is the total area of the ink layer of each color in any part of the width direction. The bone plate data is created by correcting the bone plate basic data of the correction ink so as to be 60 to 110% of the maximum value of
Printing with an ink for each color ink using a plate roller for each color ink produced based on the plate making data, and printing with a correction ink using a bone plate roller produced with the bone plate data, A method for producing a printing film, comprising: continuously applying to one surface of the long plastic film and winding the film on a roller.   The printing using the printing roller and the printing by the bone printing roller are performed to form the printing unit surface, and then an adhesive is applied onto the printing unit surface and wound around the roller. The manufacturing method of the printing film as described in any one of.   The said printing film is cut | disconnected for every said printing unit surface, and is wound and fixed and used for the surface of the can body part of a metal can so that this printing unit surface may become an inner surface. A method for producing a printed film.

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