Printing apparatus and method for producing printed matter

Abstract

To evaluate the degree of solidification of printing ink in real time.SOLUTION: A printing apparatus 100 includes: a printing unit 20 that performs offset printing on a substrate 102 using four CMYK color printing inks; a solidification unit 30 that cures the printing ink printed on the substrate 102 by irradiating active energy rays from an active energy ray irradiation source 31 to obtain a printed matter; a detection unit 40 that detects the degree of solidification of the printing ink in the printed matter using an infrared absorption measurement method with a detector 41; and a determination unit 50 that determines, with reference to a calibration curve, whether the degree of solidification detected by the detection unit 40 has reached a specific standard.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a printing apparatus and a method for manufacturing a printed matter.

Background Art

[0002] Printing is a method for manufacturing a design sheet material (hereinafter referred to as a printed matter) and includes various steps. Among them, the step of drying and / or curing (hereinafter referred to as solidification) in order to fix printing ink on a base material is an important step that affects the design and performance of the printed matter. Conventionally, in the solidification step, a good solidification state has been obtained by supplying more energy than necessary. A good solidification state is an important factor for ensuring, for example, prevention of reverse transfer and rubbing between paper surfaces, reduction of design degradation, and suppression of migration in food packaging materials.

[0003] Recently, due to the increasing movement to suppress environmental destruction caused by a rapid increase in energy consumption, in printing as well, control of excessive energy supply for solidification and release of printing inks that can be solidified with lower energy than conventional ones have attracted attention. For example, as a method for evaluating the degree of curing of an active energy ray-curable resin composition, a method of measuring the coloring of a leuco dye has been proposed (Patent Document 1).

[0004] In addition, as a method for measuring the amount of energy related to solidification during printing, label indicator commercial materials can be mentioned. For example, the ultraviolet ray detection material "UV Label" (registered trademark) manufactured by NOF Corporation and the radiation label "XR Label" (registered trademark) for blood irradiation confirmation manufactured by the same company can be mentioned. The former develops color from colorless to colored by ultraviolet rays, and the latter changes color from yellow to red by radiation. Furthermore, as a commercial material used for measuring the amount of thermal energy, the temperature indicating material "Thermo Label" (registered trademark) manufactured by the same company can be mentioned.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, in the control of energy supply for solidification, there is a concern that for some printed materials, due to unpredictable minor troubles, only less than the minimum required energy is supplied, resulting in a situation where the quality of the printed materials cannot be guaranteed.

[0007] Leuco dyes for measuring coloring have low light stability. When an active energy ray-curable resin composition containing a leuco dye is formed into a sheet and used, there is a concern about the accuracy of evaluating the degree of curing when used after long-term storage. Also, when measuring the amount of energy related to solidification during printing using a label indicator commercial material, it is necessary to attach it to printing equipment in advance, and there are problems such as rewinding the base film and re-stacking the base paper after attachment. Real-time attachment during printing requires the introduction of attachment equipment and a significant change in the printing environment, and it is not practical to introduce attachment equipment to existing printing machines.

[0008] After printing, it takes a great deal of effort to confirm the degree of solidification of the printed material at fixed points and to identify the range of poor solidification when it is confirmed within a specific range. Also, if the range of poor solidification is not identified, in order not to distribute poor solidification products to the market, it is necessary to discard the maximum range considered to have poor solidification, leading to a loss of resources.

[0009] Therefore, an object of the present invention is to provide a printing apparatus and a method for manufacturing a printed material capable of confirming the degree of solidification of the printed material in real time.

MEANS FOR SOLVING THE PROBLEMS

[0010] In order to solve the above problems, the printing apparatus according to the present application includes a printing unit that prints on a substrate with printing ink, a curing unit that cures the printing ink printed on the substrate to obtain a printed matter, a detection unit that detects the degree of curing of the printing ink in the printed matter, and a determination unit that determines whether the detection result of the degree of curing satisfies a standard.

[0011] The printing unit may be configured by at least any one of an offset printing machine, a gravure printing machine, a flexographic printing machine, an inkjet printing machine, a resin relief printing machine, a dry offset printing machine, and a digital printing machine. The curing unit may cure the printing ink by irradiating active energy rays. The active energy rays may include at least one of an electron beam and ultraviolet rays.

[0012] The detection unit may detect the degree of curing of the printing ink by non-contact measurement. The non-contact measurement may include an infrared absorption measurement method. The determination unit may determine the degree of curing of the printing ink with reference to a calibration curve.

[0013] The printing apparatus may further include a paper feeding unit that supplies a substrate and a paper discharging unit that stores the substrate that has passed through the curing unit. A cutting unit that cuts the printed matter may be further included after the curing unit and before the paper discharging unit.

[0014] The method for manufacturing a printed matter according to the present application includes a step of printing on a substrate with printing ink, a step of curing the printing ink printed on the substrate to obtain a printed matter, a step of detecting in-line the degree of curing of the printing ink in the printed matter, and a step of determining whether the detection result of the degree of curing satisfies a standard.

[0015] In the step of curing the printing ink, the printing ink may be cured by irradiating active energy rays. The active energy rays are an electron beam, and the printing ink may include an electron beam curable composition. The active energy rays are ultraviolet rays, and the printing ink may include an ultraviolet curable composition.

[0016] The step of detecting the degree of curing of the printing ink may detect the degree of curing of the printing ink by non-contact measurement. The step of detecting the degree of curing of the printing ink may detect the degree of curing of the printing ink by infrared absorption measurement.

[0017] If the printed matter has a non-patterned part, the step of detecting the degree of curing of the printing ink may detect the degree of curing of the printing ink in the non-patterned part. The step of determination may determine the degree of curing of the printing ink with reference to a calibration curve. The step of determination may determine the degree of curing of the patterned part based on the detected degree of curing in the non-patterned part.

Advantages of the Invention

[0018] According to the present invention, it is possible to evaluate the degree of curing of the printing ink in real time while manufacturing a printed matter with a printing apparatus, and it is possible to quickly identify a range in which the degree of curing does not reach the standard.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof.

[0021] The terms used in this embodiment will be described. "(Meth)acryloyl" means acryloyl and / or methacryloyl (methacryloyl), and "(meth)acrylate" means acrylate and / or methacrylate (methacrylate). "Active energy ray" means an energy ray having the property of causing a chemical change such as a chemical reaction in the irradiated material by irradiation, such as ultraviolet rays or electron beams.

[0022] In this embodiment, the numerical range indicated by "~" includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the plurality of numerical ranges described stepwise in this embodiment, the upper limit value or the lower limit value of a certain step's numerical range can be arbitrarily combined with the upper limit value or the lower limit value of the numerical range of other steps. Also, the materials and compounds exemplified in this embodiment may be used alone or in combination of two or more, unless otherwise specified.

[0023] FIG. 1 is a block diagram showing a schematic configuration of a printing apparatus 100 according to this embodiment. The printing apparatus 100 includes, in the order in which a base material 102 advances through the printing apparatus 100, a paper feeding unit 10 that supplies a sheet-like base material 102 such as paper, a printing unit 20 that prints printing ink on the base material 102, a curing unit 30 that cures the printing ink to obtain a printed matter, a detection unit 40 that detects the degree of curing of the cured printing ink, a determination unit 50 that determines whether the detected degree of curing has reached a standard, a cutting unit 60 that cuts the base material 102 into a predetermined size, and a paper discharging unit 70 that stacks and stores the cut printed matter 103.

[0024] In the printing apparatus 100, the paper feeding unit 10 accommodates a roll 101 around which a sheet-like substrate 102 such as paper is wound, and pulls out and supplies the substrate 102 from the roll 101. The printing unit 20 is an offset printing rotary machine that performs color printing on the sheet-like substrate 102. In the direction in which the substrate 102 advances, a black (K) printing unit 21, a cyan (C) printing unit 22, a magenta (M) printing unit 23, and a yellow (Y) printing unit 21 are arranged in this order. The black printing unit 21 has a pressure cylinder 21a, an offset cylinder 21b, and a plate cylinder 21c, and further, an ink roller 21d and a water roller 21e are arranged around the plate cylinder 21c. The cyan printing unit 22, the magenta printing unit 23, and the yellow printing unit 24 also have the same configuration as the black printing unit 21.

[0025] The curing unit 30 irradiates the substrate 102 printed with printing ink in the printing unit 20 with active energy rays such as electron beams from an active energy ray irradiation source 31 to cure the printing ink and obtain a printed matter. The detection unit 40 detects a change in the properties of the printing ink in a non-contact manner, for example, by an infrared absorption measurement method, using a detector 41 for the printing ink cured in the curing unit 30. The determination unit 50 converts the degree of curing of the printing ink by referring to a calibration curve from the detection amount obtained by the detection unit 40, and determines that it is qualified if the degree of curing reaches a specific standard, and determines that it is unqualified if it does not reach the standard. The determination unit 50 may be provided with input means such as buttons and display means such as a display in order to set a specific standard or display the result of the determination. Further, the determination unit 50 may be provided with a storage unit that stores data of the calibration curve and specific standards. The cutting unit 60 cuts the substrate 102 into a predetermined size with a blade 61. The paper discharging unit 70 stacks and accommodates the printed matter 103 cut by the cutting unit. The cutting unit 60 may be located behind the paper discharging unit 70.

[0026] Note that the printing apparatus 100 of the present embodiment is shown as an example, and the present invention is not limited to such a configuration. Although the printing unit 20 shows a rotary press for offset printing that performs four-color printing on one side of the base material 102, the printing method is not limited to offset printing, and it can also be applied to a sheet-fed printing press instead of a rotary press using roll paper. Further, it can be applied not only to the case of performing four-color printing on one side, but also to double-sided printing, single-color printing, printing with four or more colors, etc. Further, it can also be applied to printing of varnish that does not contain color pigments. The curing of the printing ink in the curing unit 30 is not limited to irradiation with active energy rays such as electron beams from the active energy ray irradiation source 31, and may be by other methods such as heating. The detection unit 40 may measure changes in the properties of the printing ink by other measurement methods not limited to the infrared absorption measurement method, and the detector 41 may measure in contact with the printing ink instead of non-contact.

[0027] FIG. 2 is a flowchart showing a series of steps of a method for manufacturing a printed matter in the printing apparatus 100. Hereinafter, the method for manufacturing a printed matter will be described with reference to this flowchart.

[0028] In the paper feeding step of step S1, a sheet-shaped base material 102 is supplied from the paper feeding unit 10. The paper feeding unit 10 pulls out the base material 102 from the roll 101 and continuously supplies it downstream. A predetermined tension is applied to the base material 102, and it is supplied downstream at a predetermined speed. Note that the paper feeding unit 10 may supply the base material 102 having a predetermined size sheet by sheet instead of continuously supplying the base material 102 wound around the roll 101.

[0029] <Base material> The base material 102 may be any sheet material on which printing ink can be printed. Examples of paper sheet materials include ordinary paper or cardboard, etc., and the thickness is not particularly limited. The paper sheet material may have its surface vapor-deposited with a metal such as aluminum for the purpose of imparting design properties. Further, the paper base material may be surface-coated with an acrylic resin, urethane resin, polyester resin, polyolefin resin, or other resin, etc., and furthermore, surface treatment such as corona treatment may be performed. For example, specific examples of the surface-treated paper base material include coated paper and art paper, etc.

[0030] Examples of resin sheet materials include, for example, polyolefin base materials such as polyethylene and polypropylene, polyester base materials such as polyethylene terephthalate and polylactic acid, polycarbonate base materials, polystyrene-based base materials such as polystyrene, AS resin, and ABS resin, nylon base materials, polyamide base materials, polyvinyl chloride base materials, polyvinylidene chloride base materials, cellophane base materials, paper base materials, aluminum base materials, etc., or film-like base materials made of composite materials thereof.

[0031] In addition, for the base material 102, an inorganic compound such as silica, alumina, or aluminum can also be used as a vapor-deposited base material vapor-deposited on the film base material. Further, the vapor-deposited surface may be coated with polyvinyl alcohol or the like.

[0032] It is preferable that the surface of the base material 102 to be printed (the surface in contact with the printing layer) is subjected to easy adhesion treatment. Specific examples of easy adhesion treatment include corona discharge treatment, ultraviolet / ozone treatment, plasma treatment, oxygen plasma treatment, primer treatment, etc. Also, in the case of a polyethylene terephthalate base material, when sufficient adhesion cannot be obtained, surface treatment such as acrylic coating treatment, polyester treatment, or polyvinylidene chloride treatment may be performed.

[0033] In the printing process of step S2, a printed matter is obtained by printing printing ink on the base material 102 supplied from the paper feeding unit 10 with the printing unit 20. The printing unit 20 of the printing apparatus 100 is configured by, for example, an offset printing rotary press that performs four-color printing. In the printing unit 20, in the black printing unit 21, the cyan printing unit 22, the magenta printing unit 23, and the yellow printing unit 21, the base material 102 is printed with the printing ink of each color to obtain a color printed matter.

[0034] <Printing> Printing is not limited to offset printing, and can be formed using known printing methods such as gravure printing, flexographic printing, inkjet printing, resin letterpress printing machines, dry offset printing machines, digital printing machines, or combinations thereof. The printing speed, that is, the speed at which the base material 102 advances through the printing apparatus 100, is not particularly limited, but is preferably 10 m / min or more, more preferably 30 m / min or more, still more preferably 50 m / min or more, and even more preferably 80 m / min or more. By having a printing speed higher than this, the time from the printing process of step S2 to the subsequent curing process of step S3 can be shortened, and changes in properties before and after irradiation due to reasons other than curing can be suppressed.

[0035] <Printing ink> The printing ink is a liquid that can be printed on the base material, and is not limited as long as it has the property of curing after the curing process described later. For example, as an oil-based ink in rotary printing, it may contain a solvent sufficient for heat setting. Also, for example, as an oil-based ink in sheet-fed printing, it may contain a sufficient amount of unsaturated fatty acid. Also, for example, as an active energy ray curable ink in active energy ray irradiation printing, it may contain a radically polymerizable compound.

[0036] A radically polymerizable compound is a compound having a radically polymerizable ethylenically unsaturated bond, and it may be a compound having at least one ethylenically unsaturated bond in the molecule, including those having chemical forms such as monomers, oligomers, polymers, etc. The radically polymerizable compound may be used alone or in combination of two or more. Examples of the radically polymerizable compound include unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, maleic acid and their salts, anhydrides having an ethylenically unsaturated group, acrylonitrile, styrene, and various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, unsaturated urethanes, etc. More specifically, as the radically polymerizable compound, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, β-carboxyethyl (meth)acrylate, 4-tert-butylcyclohexanol (meth)acrylate, tetrahydrofurfuryl acrylate, alkoxylated tetrahydrofurfuryl acrylate, caprolactone (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isoamyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, 3,3,5-trimethylcyclohexanol (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl(oxyethyl)(meth)acrylate, 1,4-cyclohexanedimethanol (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, benzyl (meth)acrylate, EO-modified (2) nonylphenol acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, acryloylmorpholine, N-vinylcarbazole, 1-vinylimidazole, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinylformamide and other monofunctional radically polymerizable compounds;1,3-Butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, polyethylene glycol (300) di(meth)acrylate, polyethylene glycol (400) di(meth)acrylate, polyethylene glycol (600) di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, EO-modified (2) 1,6-hexanediol di(meth)acrylate, PO-modified (2) neopentyl glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, EO-modified (4) bisphenol A di(meth)acrylate, PO-modified (4) bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tris(2-hydroxyethyl) isocyanurate di(meth)acrylate and other difunctional radically polymerizable compounds; trimethylolpropane tri(meth)acrylate, EO-modified (3) trimethylolpropane tri(meth)acrylate, PO-modified (3) trimethylolpropane tri(meth)acrylate, ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate, ethoxylated isocyanuric acid tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate and other trifunctional radically polymerizable compounds; pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate and other tetrafunctional radically polymerizable compounds; dipentaerythritol penta(meth)acrylate and other pentafunctional radically polymerizable compounds;Examples thereof include hexafunctional radically polymerizable compounds such as dipentaerythritol hexa(meth)acrylate. As the radically polymerizable compound, urethane acrylates such as aliphatic urethane acrylate and aromatic urethane acrylate as unsaturated urethanes; polyester acrylates as unsaturated polyesters; polyether acrylates as unsaturated polyethers can be used, and epoxy acrylate etc. can also be used.

[0037] The printing ink can contain the substances shown below, but those having properties that suppress or inhibit the detection in the detection step of step S4 described later are not preferred. For example, when the means for detecting the degree of solidification of the printed matter is colorimetric measurement, the inclusion of a color pigment may reduce the color difference before and after solidification, and colorimetric detection may be inhibited. Also, for example, when the means for detecting the degree of solidification of the printed matter is infrared absorption measurement, if the printed matter contains a substance having an infrared absorption frequency at an infrared measurement frequency such as C=C stretching vibration or C-H out-of-plane bending vibration, where the difference in peak intensity before and after solidification is relatively large, it will lead to a decrease in the accuracy of the calibration curve. Also, for example, when the means for detecting the degree of solidification of the printed matter is optical interference measurement, if the printed matter contains a substance that gives unevenness to the surface of the printed matter, it will lead to a decrease in the accuracy of the calibration curve. Also, for example, when the means for detecting the degree of solidification of the printed matter is luminescence measurement, if the printed matter contains a substance that strongly emits light regardless of the degree of solidification, such as a fluorescent brightening agent that absorbs ultraviolet light and emits light, it will lead to a decrease in the accuracy of the calibration curve. In any case, the accuracy can also be improved, for example, by measuring the background and using multivariate analysis. In one embodiment, luminescence refers to a phenomenon in which part of the energy released in the process of transition from an excited state to a ground state becomes light, and includes fluorescence and phosphorescence.

[0038] The printing ink can contain extender pigments. By using extender pigments, the fluidity and film strength of the printing ink can be adjusted, and paper surface contamination during printing can be suppressed. The printing ink can contain resins. By using resins, appropriate elasticity can be imparted to the printing ink, and it can contribute to the dispersion of color pigments. The printing ink can contain photoinitiators. Particularly when the active energy ray is ultraviolet light, it plays a role in polymerizing and polymerizing radical polymerizable compounds. The printing ink can contain organic pigments and / or inorganic pigments. By using color pigments, the printed matter can be colored, and by using a plurality of printing inks having different color pigments, a colorful printed matter can be obtained. The printing ink can optionally contain, as necessary, colorants, waxes, leveling agents, antistatic agents, surfactants, defoaming agents, polymerization inhibitors, ultraviolet absorbers, antioxidants, antioxidants (preservatives), and the like.

[0039] The printing ink can contain thermochromic materials and photochromic materials. In one embodiment, these materials refer to materials that change color or emit light due to a change in molecular structure or zwitterionization by supplying energy such as heat or active energy rays. For example, as discoloring materials, leuco dyes such as leuco crystal violet and 4,4’,4’’-tris-di-β-hydroxyethylaminotriphenylacetonitrile (HHEVC) can be mentioned. As light-emitting materials, spiro pyran compounds such as 1,3,3,―trimethylindolinobenzopyrrospirapyran, diarylethene compounds, azobenzene compounds, and the like can be mentioned.

[0040] In addition, a photoinitiator can also be used as a light-emitting material. Any photoinitiator that emits light can be used, and there is no particular limitation. However, as one embodiment, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4-diethylthioxanthen-9-one, 4,4'-bis(diethylamino)benzophenone, Esacure One (manufactured by iGM), etc. can be mentioned.

[0041] In the solidification step of step S3, printing ink is printed on the base material 102 supplied from the paper feeding unit 10 by the printing unit 20. In the solidification unit 30, the base material 102 on which the printing ink has been printed by the printing unit 20 is irradiated with active energy rays from the active energy ray irradiation source 31 to solidify the printing ink, and a printed matter including the base material 102 and the solidified printing ink is obtained. The solidification of the printing ink may be by drying, and in that case, a cooling step of cooling the printed matter heated by drying may be provided.

[0042] <Solidification> In one embodiment, solidification refers to the solidification of the printing ink by thermal energy, active energy ray energy, etc. Solidification can be broadly divided into drying and curing. In one embodiment, drying refers to the solidification of the printing ink by methods such as oxidation polymerization type, evaporation drying type, penetration drying type, etc., and curing refers to the polymerization of the (meth)acryloyl group of the radical polymerizable compound proceeding by active energy rays and the solidification of the printing ink.

[0043] <Printed matter> In one embodiment, the printed matter is a sheet-like material containing a substrate and a substance in which the printing ink has solidified (hereinafter referred to as a coating film). The coating film is preferably a thin film with a thickness of several hundred nm to several tens of μm. When the coating film is thin, the detected value is small, and there is a risk that the detection accuracy will decrease. When the coating film is thick, there is a risk that the degree of solidification will be different between the substrate side and the outermost surface in the solidification step of step S3.

[0044] In the detection step of step S4, in order to detect the degree of solidification of the printing ink solidified on the coating film in step S4 inline, the detector 41 provided in the detection unit 40 measures the properties of the printing ink. Since the properties of the printing ink change depending on the degree of solidification, the amount of change is output as the detected amount. The detector 41 may be a non-contact detector such as an infrared spectrometer, a fluorescence spectrometer, a Raman scattering spectrometer, or a detector that contacts the printing ink.

[0045] <Degree of solidification> The degree of solidification is the degree of drying or curing of the coating film in which the printing ink has been solidified in the solidification unit 30. The degree of drying is the stickiness of the coating film, and the degree of curing is the degree of polymerization of the (meth)acryloyl group of the radically polymerizable compound.

[0046] <Inline> Inline is the process from when the substrate 102 is supplied from the paper feeding unit 10 to when it reaches the paper discharging unit 70 in the printing apparatus 100. Although not included in the printing apparatus 100 shown in FIG. 1, the inline can include devices such as an automatic paper folding machine and a reversing machine. These devices not related to printing are not particularly limited, but the number of devices included between the printing unit 20 that performs the printing step of step S1 and the solidification unit 30 that performs the solidification step of step S3 is preferably two or less, and more preferably one or less. By having one or less devices, the time from the end of the printing step of step S1 to the start of the solidification step of step S2 can be shortened, and changes in the properties of the printing ink caused by factors other than solidification can be suppressed.

[0047] <Detection> The detection is to detect a change in properties that occurs due to the solidification of the printing ink. For example, it is to detect the color difference between the printing ink and the coating film due to solidification. Also, for example, it is to detect the decrease in the absorption band derived from C=C bonds due to curing, the broadening or sharpening of other absorption bands, or the change in interference fringes due to solidification. Also, for example, it is to detect the change in the emission state including fluorescence and phosphorescence due to solidification.

[0048] These detections can be carried out on the pattern part of the printed matter or on the non-pattern part. Here, the pattern part is the part that imparts design and performance to the printed matter. Also, the non-pattern part is the part that imparts performance without emphasizing design, and examples include parts where color patches and trim marks are printed. These observations are preferably carried out on the non-pattern part. When carried out on the non-pattern part, it is easy to detect the change in properties caused by curing without being inhibited by the printing ink applied complicatedly for design, and by quantitatively observing, the degree of solidification can be quantitatively observed.

[0049] In the determination step of step S5, based on the detection result obtained in the detection step of step S4, it is determined whether the degree of solidification of the printing ink meets a specific standard. For example, as shown in an example in FIG. 3, the determination unit S5 may refer to a calibration curve showing the correspondence between the detected amount obtained by the detection unit S4 and the degree of solidification of the printing ink, and convert the detected amount into the degree of solidification of the printing ink. Then, it may be determined as qualified if the solidified ink of the printing ink has reached a predetermined reference value, and determined as unqualified if it has not reached the reference value. The determination unit 50 may create in advance the relationship between the detected amount and the degree of solidification of the printing ink as a calibration curve. Also, the determination unit 50 may create in advance the relationship between the detected amount in the non-pattern part and the degree of solidification of the printing ink in the pattern part as a calibration curve. In this case, the detected amount in the non-pattern part may be converted into the degree of solidification of the printing ink in the pattern part by referring to the calibration curve, and the degree of solidification of the printing ink may be determined.

[0050] <specific standard> A specific standard is a detection result calculated by statistical analysis to achieve a certain degree of solidification. In one embodiment, the statistical process may be univariate analysis or multivariate analysis. As one embodiment, it is preferable to create a calibration curve in advance by statistical processing for the correlation between the degree of solidification and the detection result. In this case, the degree of solidification can be quantitatively evaluated.

[0051] In the paper discharge process of step S6, the substrate 102 that has completed a series of processes in the printing apparatus 100 is received and accommodated. The substrate 102 that has completed the detection process of step S5 in the detection unit 40 is sent to the paper discharge unit 70 after being cut into a predetermined size by the blade 61 provided in the cutting unit 60. The paper discharge unit 70 stacks and stores the substrate 102 that has been sized and cut, that is, the printed matter 103, and discharges them together. Since it has been determined by the determination unit 50 whether the degree of solidification of the printed ink detected inline by the detection unit 40 satisfies a specific standard as described above, it is clear whether the printed matter 103 stored in the paper discharge unit 70 is qualified or unqualified.

[0052] As described above, the printing apparatus 100 of the present embodiment incorporates a detection unit 40 that detects the degree of solidification of the printed ink in the printing apparatus 100 and a determination unit 50 that determines whether the degree of solidification satisfies a specific standard, so that the degree of solidification of the printed ink can be evaluated in real time, and the range of printed matter with a degree of solidification not reaching the standard can be quickly specified.

[0053] Also, the method for manufacturing a printed matter of the present embodiment, in the method for manufacturing a printed matter in the printing apparatus 100, by incorporating an in-line detection step S4 for detecting the degree of solidification of the printed ink and a determination step S5 for determining whether the degree of solidification satisfies a specific standard into a series of steps for manufacturing the printed matter, the degree of solidification of the printed ink can be evaluated in real time while manufacturing the printed matter with the printing apparatus 100, and the range of printed matter with a degree of solidification not reaching the standard can be quickly specified.

Explanation of Reference Numerals

[0054] 10 Sheet Feeding Unit 20 Printing Unit 21a Pressure Cylinder 21b Offset Cylinder 21c Plate Cylinder 21d Ink Roller 21e Water Roller 30 Curing Unit 31 Active Energy Ray Irradiation Source 40 Detection Unit 41 Detector 50 Judgment Unit 60 Cutting Unit 70 Sheet Discharging Unit 100 Printing Device 102 Substrate

Claims

1. A printing unit that prints on a substrate with printing ink, A curing unit that cures the printing ink printed on the substrate to obtain a printed matter, A detection unit that detects the degree of curing of the printing ink in the printed matter, A determination unit that determines whether the detection result of the degree of curing meets a standard A printing apparatus including the above.

2. The printing apparatus according to claim 1, wherein the printing unit is constituted by at least one of an offset printing machine, a gravure printing machine, a flexographic printing machine, an inkjet printing machine, a resin letterpress printing machine, a dry offset printing machine, and a digital printing machine.

3. The printing apparatus according to claim 1, wherein the curing unit cures the printing ink by irradiating active energy rays.

4. The printing apparatus according to claim 3, wherein the active energy rays include at least one of an electron beam and ultraviolet rays.

5. The printing apparatus according to claim 1, wherein the detection unit detects the degree of curing of the printing ink by non-contact measurement.

6. The printing apparatus according to claim 5, wherein the non-contact measurement includes an infrared absorption measurement method.

7. The printing apparatus according to claim 1, wherein the determination unit determines the degree of curing of the printing ink with reference to a calibration curve.

8. A paper feeding unit that supplies the substrate, A paper discharging unit that stores the substrate that has passed through the curing unit The printing apparatus according to claim 1, further including the above.

9. The printing apparatus according to claim 8, further including a cutting unit that cuts the printed matter at a stage after the curing unit and before the paper discharging unit.

10. A step of printing on a substrate with printing ink, A step of curing the printing ink printed on the substrate to obtain a printed matter, A step of in-line detecting the degree of curing of the printing ink in the printed matter, A step of determining whether the detection result of the degree of curing meets a standard A method for manufacturing a printed matter including the above.

11. The method for manufacturing a printed matter according to claim 10, wherein the step of curing the printing ink cures the printing ink by irradiating active energy rays.

12. The method for manufacturing a printed matter according to claim 11, wherein the active energy ray is an electron beam, and the printing ink includes an electron beam curable composition.

13. The method for manufacturing a printed matter according to claim 11, wherein the active energy ray is ultraviolet rays, and the printing ink includes an ultraviolet curable composition.

14. The method for manufacturing a printed matter according to claim 10, wherein the step of detecting the degree of curing of the printing ink detects the degree of curing of the printing ink by non-contact measurement.

15. The step of detecting the degree of curing of the printing ink is the method for manufacturing a printed matter according to claim 14, wherein the degree of curing of the printing ink is detected by an infrared absorption measurement method.

16. The printed matter has a non-patterned portion, and the step of detecting the degree of curing of the printing ink is the method for manufacturing a printed matter according to claim 10, wherein the degree of curing of the printing ink in the non-patterned portion is detected.

17. The step of making the determination is the method for manufacturing a printed matter according to claim 10, wherein the degree of curing of the printing ink is determined with reference to a calibration curve.

18. The printed matter has a non-patterned portion, and the step of detecting the degree of curing of the printing ink is to detect the degree of curing of the printing ink in the non-patterned portion, and the step of making the determination is to determine the degree of curing of the patterned portion of the printed matter based on the detected degree of curing in the non-patterned portion. The method for manufacturing a printed matter according to claim 17.

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