JP2019162794A - Printer, printing method and substrate - Google Patents

Abstract

The present invention provides a printing apparatus, a printing method, and a base material on which an image is printed by the printing method, in which an ink layer formed on a surface of the base material can be prevented from being peeled off by heat sealing in a later step. A control unit of the printing apparatus includes a processing condition acquisition unit, a film thickness range determination unit, and a print instruction unit. The processing condition acquisition unit 51 acquires the processing condition H of the heat sealing. The film thickness range determining unit 52 determines the allowable range R of the film thickness of the ink layer formed on the surface of the base material 9 based on the processing condition H obtained by the processing condition obtaining unit 51. The print instruction unit 53 controls the inkjet printing unit 20 so that the thickness of the ink layer falls within the allowable range R. Thereby, the thickness of the ink layer formed on the surface of the base material 9 can be adjusted based on the processing condition H of the heat sealing processing. Therefore, it is possible to prevent the ink layer formed on the surface of the base material 9 from being peeled off by a heat sealing process in a later step. [Selection diagram] FIG.

Description

  The present invention relates to a printing apparatus and a printing method for printing an image by an inkjet method on the surface of a PTP packaging substrate that is heat-sealed in a subsequent process, and a substrate on which an image is printed by the printing method.

  PTP packaging is known as a packaging for tablets or capsules. PTP packaging is obtained by laminating a resin container sheet having a plurality of cups that contain tablets or capsules and an aluminum belt-like base material by heat sealing. Conventionally, chemical names, logo marks, and the like have been printed on the PTP packaging base material by gravure printing.

  In recent years, it has been required to print not only a drug name and a logo mark but also additional information such as a production number and a dosing period on a PTP packaging substrate. Since this type of additional information is frequently changed, it has been difficult to cope with conventional gravure printing. Therefore, attention has been paid to a technique for printing additional information on a base material after gravure printing by an ink jet method that can easily cope with a change in printing contents.

  For example, Patent Documents 1 and 2 describe conventional apparatuses that perform printing by an inkjet method.

JP 2003-182062 A JP 2005-096277 A

  However, when an image is printed on an aluminum base material for PTP packaging by an ink jet method and then the base material is attached to a container sheet by heat sealing, an image is formed at the time of heat sealing processing or after heat sealing processing. A part of the ink layer may be peeled off.

  The present invention has been made in view of such circumstances, and a printing apparatus, a printing method, and the printing method that can prevent the ink layer formed on the surface of the base material from being peeled off by a heat-sealing process in a later step. An object of the present invention is to provide a substrate on which an image is printed.

  In order to solve the above problems, a first invention of the present application is a printing apparatus that prints an image by an inkjet method on a surface of a base material for PTP packaging that is heat-sealed in a subsequent process, and has a predetermined transport path A transport mechanism that transports the base material along the surface, an ink jet printing unit that ejects ink droplets toward the surface of the base material transported by the transport mechanism, and controls the transport mechanism and the ink jet printing unit. A control unit, and the control unit is formed on the surface of the base material based on the processing condition acquisition unit that acquires the processing condition of the heat seal processing and the processing condition acquired by the processing condition acquisition unit. A film thickness range determining unit that determines a permissible range of the ink layer thickness, and the inkjet printing unit so that the film thickness of the ink layer falls within the permissible range. It has a printing instruction unit, the.

  2nd invention of this application is the printing apparatus of 1st invention, Comprising: The said process conditions include the temperature information of the said heat seal process.

  3rd invention of this application is the printing apparatus of 1st invention or 2nd invention, Comprising: The said process conditions include the pressure information of the said heat seal process.

  4th invention of this application is a printing apparatus of any one invention from 1st invention to 3rd invention, Comprising: The said film thickness range determination part determines the upper limit of the said tolerance | permissible_range based on the said process conditions. To do.

  5th invention of this application is a printing apparatus of 4th invention, Comprising: The said film thickness range determination part sets the said upper limit to the value of 3.5 micrometers or more and 8.0 micrometers or less.

  A sixth invention of the present application is the printing apparatus according to the fourth invention or the fifth invention, wherein the film thickness range determining unit further determines a lower limit value of the allowable range.

  A seventh invention of the present application is the printing apparatus according to any one of the first to sixth inventions, wherein the print instruction unit corrects a density value of image data to be printed in accordance with the allowable range. To do.

  An eighth invention of the present application is the printing apparatus according to any one of the first to sixth inventions, wherein the print instruction unit sets the size of the ink droplets ejected from the inkjet printing unit to the allowable range. Change according to.

  A ninth invention of the present application is the printing apparatus according to any one of the first to sixth inventions, wherein the print instruction unit adjusts the temperature of the ink jet printing unit according to the allowable range.

  A tenth invention of the present application is the printing apparatus according to any one of the first to ninth inventions, wherein the control unit is a second color image arranged in front of the first color image and the first color image. Input image data composed of a color image is converted into print image data composed of an extracted image obtained by erasing an overlapping portion from the first color image with the second color image and the second color image. The inkjet printing unit is controlled based on the printing image data.

  An eleventh invention of the present application is a printing method in which an image is printed on the surface of the base material by an inkjet method while conveying the base material for PTP packaging in which heat sealing is performed in a post-process, and a) the heat Obtaining a processing condition for sealing, b) determining an allowable range of the thickness of the ink layer formed on the surface of the substrate based on the processing condition, c) a film of the ink layer And a step of ejecting ink droplets toward the surface of the substrate so that the thickness is within the allowable range.

  A twelfth invention of the present application is a base material for PTP packaging, and an image is printed by the printing method of the eleventh invention.

  A thirteenth invention of the present application is the substrate of the twelfth invention, wherein the ink layer has a thickness of 2.0 μm or more and 8.0 μm or less.

  According to the first to thirteenth inventions of the present application, the film thickness of the ink layer formed on the surface of the substrate is adjusted based on the processing conditions of the heat sealing process. Thereby, it can suppress that the ink layer formed in the surface of a base material peels by the heat seal process of a post process.

It is a figure which shows the structure of a printing apparatus. It is a bottom view of a head unit and a light irradiation part for thickening. It is a schematic diagram of the packaging apparatus which performs PTP packaging of a tablet. It is the figure which showed the result of having tested the presence or absence of peeling of the ink layer after heat seal processing. It is the block diagram which showed notionally the function in the control part for implement | achieving the film thickness adjustment of an ink layer. 5 is a flowchart showing a flow of printing processing. It is the figure which showed the example of table data. It is the figure which showed the example of the table data which concerns on a modification. 10 is a flowchart illustrating a flow of printing processing according to a modification. 10 is a flowchart illustrating a flow of printing processing according to a modification. It is the figure which showed notionally the mode of the blank character processing.

  Embodiments of the present invention will be described below with reference to the drawings.

<1. Configuration of printing device>
FIG. 1 is a diagram illustrating a configuration of a printing apparatus 1 according to an embodiment of the present invention. The printing apparatus 1 is an apparatus that prints an image by an inkjet method on the surface (printed surface) of an aluminum substrate 9 used for PTP (press through pack) packaging of tablets and capsules. On both surfaces of the substrate 9, a gravure printing layer and a resin layer for protecting the gravure printing layer are formed in advance. In addition, a layer of a heat sealant that melts at the time of heat seal processing described later is formed on the back surface of the substrate 9 in advance.

  As illustrated in FIG. 1, the printing apparatus 1 includes a transport mechanism 10, an inkjet printing unit 20, a thickening light irradiation unit 30, a fixing light irradiation unit 40, and a control unit 50.

  The transport mechanism 10 is a mechanism for transporting the belt-like base material 9 in the transport direction along the longitudinal direction. The transport mechanism 10 according to the present embodiment includes an unwinding unit 11, a plurality of transport rollers 12, and a winding unit 13. The base material 9 is unwound from the unwinding unit 11 and is transported along a transport path constituted by a plurality of transport rollers 12. Each transport roller 12 guides the substrate 9 to the downstream side of the transport path by rotating about the horizontal axis. In addition, the substrate 9 after the conveyance is collected to the winding unit 13.

  As shown in FIG. 1, the substrate 9 moves substantially horizontally along the arrangement direction of the plurality of head units 21 to 24 below the inkjet printing unit 20. At this time, the printing surface of the base material 9 is directed upward (the head units 21 to 24 side). Further, the transport mechanism 10 has a pair of nip rollers 14 on the downstream side of the transport path from the inkjet printing unit 20. The pair of nip rollers 14 are actively rotated at a constant speed while being in contact with both surfaces of the substrate 9 and sandwiching the substrate 9. When the substrate 9 is transported, the control unit 50 adjusts the rotation speed of the unwinding unit 11 with respect to the rotation speed of the nip roller 14. Thereby, tension is given to the substrate 9. As a result, slack and wrinkles of the base material 9 during conveyance are suppressed.

  The inkjet printing unit 20 is a mechanism that discharges ultraviolet curable ink to the base material 9 that is transported by the transport mechanism 10. The ink jet printing unit 20 of the present embodiment has four head units 21 to 24. These head units 21 to 24 apply ink droplets of C (Cyan), M (Magenta), Y (Yellow), and K (Black), which are color components of a multicolor image, to the printing surface of the substrate 9. Respectively. Each head unit 21 to 24 is fixedly arranged with respect to the frame of the printing apparatus 1.

  FIG. 2 is a bottom view of the head unit 24 and the thickening light irradiation unit 30. As shown in FIG. 2, the head unit 24 of this embodiment has two print heads 201. Further, as shown in an enlarged manner in FIG. 2, a plurality of nozzles 202 are regularly arranged on the lower surface of the print head 201. The other three head units 21 to 23 similarly have two print heads 201 each having a plurality of nozzles 202. During printing, ink droplets of each color are ejected from the plurality of nozzles 202 of the head units 21 to 24 toward the printing surface of the substrate 9. As a result, a multicolor image is printed on the printing surface of the substrate 9.

  As a method for ejecting ink droplets from the nozzle 202, for example, a so-called piezo method is used in which a voltage is applied to a piezo element to deform it, thereby pressurizing and ejecting ink in the nozzle 202. However, the ink droplet ejection method may be a so-called thermal method in which the ink in the nozzle 202 is heated and expanded by energizing the heater.

  The thickening light irradiation unit 30 is a mechanism that irradiates the substrate 9 with the first irradiation light on the downstream side of the inkjet printing unit 20 in the transport direction. As shown in FIG. 2, a plurality of LED (Light Emitting Diode) light sources 31 are regularly arranged on the lower surface of the thickening light irradiation unit 30. In the example of FIG. 2, the plurality of LED light sources 31 are two-dimensionally arranged in the transport direction and the width direction (horizontal direction orthogonal to the transport direction), but the plurality of LED light sources 31 are arranged in the width direction. They may be arranged in a line.

  The 1st irradiation light irradiated from each LED light source 31 contains the ultraviolet-ray of the wavelength band effective for hardening of the ink discharged from the head units 21-24. For this reason, when 1st irradiation light is irradiated to the ink on the base material 9, the viscosity of an ink will increase. However, the amount of the first irradiation light irradiated from the thickening light irradiation unit 30 is smaller than the amount of the second irradiation light irradiated from the fixing light irradiation unit 40. For this reason, the ink on the substrate 9 is not completely cured. That is, by the first irradiation light, the inks of the respective colors on the base material 9 are in a semi-cured state with reduced fluidity.

  When the ink is semi-cured, spreading of the ink on the substrate 9 is suppressed. Therefore, in the transport path downstream from the thickening light irradiating unit 30, the print quality is less likely to deteriorate due to ink spreading.

  The fixing light irradiation unit 40 is a mechanism that irradiates the substrate 9 with the second irradiation light on the downstream side in the transport direction from the thickening light irradiation unit 30. The fixing light irradiation unit 40 of the present embodiment includes a metal halide lamp 41 and a reflector 42. The metal halide lamp 41 is a tubular light source that extends in the width direction of the substrate 9. The metal halide lamp 41 irradiates the printed surface of the substrate 9 with the second irradiation light directly or via the reflector 42.

  The second irradiation light emitted from the metal halide lamp 41 includes ultraviolet rays in a wavelength band effective for curing ink ejected from the head units 21 to 24. Further, the second irradiation light emitted from the metal halide lamp 41 has a sufficient amount of light to completely cure the ink. For this reason, when the second irradiation light is applied to the ink on the base material 9, the ink is cured and the ink is fixed on the printing surface of the base material 9.

  The control unit 50 is means for controlling the operation of each unit in the printing apparatus 1. The control unit 50 of the present embodiment is configured by a computer having a processor 501 such as a CPU, a memory 502 such as a RAM, and a storage unit 503 such as a hard disk drive. As indicated by broken lines in FIG. 1, the control unit 50 includes the unwinding unit 11, the winding unit 13, the nip roller 14, the four head units 21 to 24, the thickening light irradiation unit 30, and the fixing unit. The light irradiation unit 40 is electrically connected to each other. The control unit 50 temporarily reads the computer program CP stored in the storage unit 503 into the memory 502, and the processor 501 performs arithmetic processing based on the computer program CP, thereby controlling the operation of each unit described above. Thereby, the printing process in the printing apparatus 1 proceeds.

  The control unit 50 is electrically connected to a server 504 installed outside the printing apparatus 1. The server 504 stores image data D to be printed. During the printing process, the substrate 9 is transported by the transport mechanism 10, and the control unit 50 reads the designated image data D from the server 504 and, based on the image data D, the respective colors from the head units 21 to 24. Ink droplets are ejected. As a result, an image corresponding to the image data D is printed on the printing surface of the substrate 9.

<2. About packaging equipment>
FIG. 3 is a schematic diagram of a packaging device 2 that performs PTP packaging of tablets or capsules using the substrate 9 on which an image is printed in the printing device 1. As illustrated in FIG. 3, the packaging device 2 includes a container sheet supply unit 61, a base material supply unit 62, a heat seal unit 63, and a product collection unit 64.

  The container sheet supply unit 61 conveys the strip-shaped container sheet 8 having a large number of cup units 81 toward the heat seal unit 63. In the container sheet supply unit 61, one tablet or capsule is put into each cup unit 81 of the container sheet 8 to be conveyed. The base material supply unit 62 conveys the belt-like base material 9 on which the image is printed in the printing apparatus 1 described above, toward the heat seal unit 63.

  The heat seal part 63 includes a first roller 631 and a second roller 632. The container sheet 8 supplied from the container sheet supply unit 61 and the substrate 9 supplied from the substrate supply unit 62 are carried into between the first roller 631 and the second roller 632. The first roller 631 rotates while contacting the container sheet 8. A plurality of recesses are provided on the outer peripheral surface of the first roller 631. Each cup part 81 of the container sheet 8 fits into this recess. The second roller 632 rotates while being in contact with the printing surface of the substrate 9.

  The second roller 632 is heated by a heater (not shown). The second roller 632 is pressed toward the first roller 631 by a pressing mechanism (not shown). For this reason, the base material 9 is attached to the container sheet 8 by heat and pressure received from the second roller 632 when passing between the first roller 631 and the second roller 632. That is, the container sheet 8 and the base material 9 are integrated by heat sealing. Thereby, the cup part 81 holding the tablet or capsule is sealed by the base material 9, and the PTP package 100 is formed.

  Thereafter, the PTP package 100 discharged from the heat seal unit 63 is cut into predetermined sizes and collected into the product collection unit 64.

<3. About peeling of ink layer>
At the time of heat sealing processing in the packaging device 2, an ink layer (hereinafter referred to as “ink layer”) that forms a printed image on the surface of the substrate 9 also receives heat and pressure from the second roller 632. Further, fine mesh-shaped blades (projections) are formed on the surface of the second roller 632. When the base material 9 passes between the first roller 631 and the second roller 632, the blade pierces the ink layer, thereby causing a fine crack in the ink layer. As a result, the ink layer may be peeled off from the printing surface of the substrate 9 at the time of heat sealing or after heat sealing, starting from the above cracks.

  FIG. 4 is a diagram showing a result of testing whether or not the ink layer is peeled after the heat sealing process by changing the film thickness of the ink layer. In the test of FIG. 4, an image is printed on the surface of the aluminum base material 9 by the printing apparatus 1 having the same structure as above, and the base material 9 and the container sheet 8 after printing are equivalent to the above. It heat-processed with the packaging apparatus 2 which has a structure. Thereafter, the tape was strongly attached to the printing surface so as not to generate air bubbles, and the tape was quickly peeled off at an angle of 180 ° to confirm the presence or absence of a peeled material attached to the tape. Then, the above operation was repeated while changing the pressure P of the second roller 632 against the first roller 631 during the heat sealing process, the temperature T of the first roller 631, and the film thickness of the ink layer. The circles in FIG. 4 indicate that there was no adherence of peeled material to the tape. The crosses in FIG. 4 indicate that the peeled material was attached to the tape.

  As shown in the results of FIG. 4, the stronger the pressure P of the second roller 632 against the first roller 631 during the heat sealing process, the higher the temperature T of the first roller 631 during the heat sealing process. Ink layers are easily peeled off. However, it can be seen from the results of FIG. 4 that the peeling of the ink layer is less likely to occur as the thickness of the ink layer is smaller.

  Specifically, when the pressure P = 0.35 [MPa] and the temperature T = 230 [° C.], it was possible to prevent the ink layer from peeling by setting the film thickness to 8.0 [μm] or less. Further, when the pressure P = 0.35 [MPa] and the temperature T = 250 [° C.], the peeling of the ink layer could be prevented by setting the film thickness to 6.5 [μm] or less. Further, when the pressure P = 0.35 [MPa] and the temperature T = 260 [° C.], the ink layer could be prevented from peeling by setting the film thickness to 6.5 [μm] or less.

  Further, when the pressure P = 0.45 [MPa] and the temperature T = 230 [° C.], it was possible to prevent the ink layer from peeling by setting the film thickness to 7.0 [μm] or less. Further, when the pressure P = 0.45 [MPa] and the temperature T = 250 [° C.], it was possible to prevent the ink layer from peeling by setting the film thickness to 5.5 [μm] or less. Further, when the pressure P = 0.45 [MPa] and the temperature T = 260 [° C.], the ink layer could be prevented from peeling by setting the film thickness to 4.5 [μm] or less.

  From this test result, if the film thickness of the ink layer is set to a value equal to or lower than the upper limit value according to the pressure P and the temperature T at the time of heat sealing processing, the ink layer is prevented from peeling off at the time of heat sealing processing or after heat sealing processing. It turned out to be possible. In the above test, the film thickness of the ink layer was measured using a retralome (for example, REM-700 manufactured by YAMATO) for the substrate 9 having the ink layer, and a digital microscope (for example, DSX510 manufactured by OLYMPUS). It was observed using.

<4. Treatment for preventing peeling of ink layer>
Hereinafter, in the printing apparatus 1, a process for adjusting the film thickness of the ink layer formed on the surface of the substrate 9 to prevent the ink layer from peeling off during or after the heat sealing process will be described. To do.

  FIG. 5 is a block diagram conceptually showing functions in the control unit 50 for realizing the adjustment of the ink layer thickness in the printing apparatus 1. As shown in FIG. 5, the control unit 50 includes a processing condition acquisition unit 51, a film thickness range determination unit 52, and a print instruction unit 53. The functions of the processing condition acquisition unit 51, the film thickness range determination unit 52, and the print instruction unit 53 are realized by the computer as the control unit 50 operating according to the computer program CP described above.

  FIG. 6 is a flowchart showing a flow of processing performed by the control unit 50 when an image is printed on the substrate 9 while adjusting the film thickness of the ink layer.

  When printing on the base material 9, first, the user of the printing apparatus 1 inputs the heat sealing process condition H to the control unit 50. The input operation may be performed by an input device such as a keyboard, a mouse, or a touch panel. Alternatively, the processing condition H may be transferred from the control unit (not shown) of the packaging device 2 to the control unit 50 of the printing device 1. The machining condition acquisition unit 51 of the control unit 50 acquires the input machining condition H (step S1). Specifically, the input machining condition H is stored in the storage unit 503. The processing conditions H of the heat sealing process include the pressure P (pressure information) of the second roller 632 with respect to the first roller 631 during the heat sealing process, and the temperature T (temperature information) of the first roller 631 during the heat sealing process. Is preferably included. However, one of the pressure P and the temperature T may be omitted.

  As shown in FIG. 5, in the storage unit 503 of the control unit 50, table data TD indicating a correspondence relationship between the heat seal processing condition H and the allowable range R of the ink layer thickness is stored in advance. ing. FIG. 7 is a diagram illustrating an example of the table data TD. In the table data TD in FIG. 7, the pressure P and temperature T, which are the processing conditions H, and the upper limit value M1 of the allowable range R of the ink layer thickness are associated with each other. The upper limit M1 is preferably set to a value not less than 3.5 μm and not more than 8.0 μm, for example. When the acquisition of the processing condition H is completed, the film thickness range determination unit 52 reads the acquired processing condition H and the table data TD from the storage unit 503. Then, the upper limit value M1 of the allowable range R corresponding to the machining condition H is determined according to the table data TD (step S2). For example, when the processing condition H is a pressure P = 0.35 [MPa] and a temperature T = 250 [° C.], the upper limit value M1 of the allowable range R is set to 6.5 [μm] with reference to the table data TD. To do.

  The print instruction unit 53 reads image data D to be printed from the server 504. Then, various conversion processes are performed on the read image data D, and the operation of the inkjet printing unit 20 is controlled based on the converted image data D. At this time, the print instruction unit 53 corrects the density value of the image data D according to the allowable range R determined in step S2 (step S3). For example, the density value of the image data D is reduced (lightened) so that the film thickness of the ink layer formed on the printing surface of the substrate 9 after printing is equal to or less than the upper limit M1 described above.

  As a specific method for reducing the density value, for example, it is conceivable to reduce the density value of the image data D before performing various conversion processes on the image data D. However, in the process of performing various conversion processes on the image data D, the density value of the image data D during or after the conversion process may be lowered than usual. For example, in the halftoning process normally performed on the image data D, the size of the halftone dot may be made smaller than usual. Further, in the process of separating the image data D into single color data of each color of CMYK, the pixel value of each single color data may be set to a smaller value than usual. Further, the tone curve used for the color tone correction of the image data D may be corrected to a lighter color side than usual.

  Thereafter, the print instructing unit 53 controls the operation of the inkjet printing unit 20 based on the image data D subjected to various conversion processes and corrected density values (step S4). Specifically, an ink droplet of a specified size is ejected from the nozzle 202 at a position specified by the corrected image data D to the substrate 9 being conveyed. Thereby, an image corresponding to the image data D is formed on the printing surface of the substrate 9. And the film thickness of the ink layer formed in the to-be-printed surface of the base material 9 becomes a value within the allowable range R described above.

  As described above, in the printing apparatus 1, the film thickness of the ink layer formed on the printing surface of the substrate 9 is adjusted based on the processing condition H of the heat sealing process. For example, when the value of the upper limit value M1 is 3.5 μm to 8.0 μm, the maximum value of the film thickness of the ink layer formed on the printing surface of the substrate 9 is 3.5 μm or more and 8 0.0 μm or less. Thereby, it can suppress that the ink formed in the to-be-printed surface of the base material 9 peels by the heat seal process of a post process.

<5. Modification>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

  In step S2 of the above embodiment, only the upper limit M1 is specified as the allowable range R of the ink layer thickness. However, if the density value of the image data D is excessively reduced, sufficient visibility may not be obtained in the printed image. For this reason, in order to ensure the visibility of the image after printing, it is preferable to specify both the upper limit value M1 and the lower limit value M2 of the allowable range R in step S2. Specifically, the table data TD referred to in step S2 may include information on the lower limit value M2 as shown in FIG. Then, the film thickness range determination unit 52 may determine the lower limit value M2 together with the upper limit value M1 of the allowable range R. The lower limit value M2 may be set to 2.0 μm as shown in FIG. 8, for example.

  By specifying the lower limit value M2 in addition to the specification of the upper limit value M1, it is possible to suppress the peeling of the ink layer due to the heat sealing process, and it is possible to prevent the image density from being excessively lowered and ensure the visibility. Specifically, the film thickness of the ink layer formed on the printing surface of the substrate 9 is preferably 2.0 μm or more and 8.0 μm or less.

  In the above embodiment, the density of the image data D is corrected in order to adjust the film thickness of the ink layer within the allowable range R. However, instead of correcting the density of the image data D, the print instruction unit 53 may change the size of the ink droplets ejected from each nozzle 202 of the print head 201 in accordance with the allowable range R. Specifically, as shown in FIG. 9, the voltage value or voltage waveform of the electrical signal supplied to the piezo element of each nozzle 202 may be corrected in step S4.

  Further, the size of the ink droplets ejected from each nozzle 202 of the print head 201 varies depending on the viscosity of the ink. And the viscosity of ink changes according to temperature. For this reason, the print head 201 may be provided with a temperature control mechanism such as a heater, and the temperature of the print head 201 may be adjusted according to the allowable range R. Specifically, as shown in FIG. 10, the print instruction unit 53 may adjust the temperature of the print head 201 according to the allowable range R before controlling the operation of the inkjet printing unit 20.

  Further, the control unit 50 may perform a so-called “extracted character” process on the image data D input from the server 504. FIG. 11 is a diagram conceptually showing the state of the extracted character processing. For example, as shown in the upper diagram of FIG. 11, the input image data D is composed of a first color image I10 and a second color image I20 arranged in front of the first color image I10. In this case, when printing is performed according to the image data D as it is, the ink layer of the first color overlaps the ink layer of the second color in the overlapping portion of the first color image I10 and the second color image I20, and the ink The film thickness of the entire layer is increased.

  In such a case, the control unit 50 converts the first color image I10 on the back side into an extracted image I11 from which an overlapping portion with the second color image I20 is deleted. Then, print image data Dp composed of the extracted extracted image I11 and the second color image I20 is generated. That is, the input image data D is converted into printing image data Dp that does not have overlapping color components. Thereafter, the control unit 50 controls the operation of the inkjet printing unit 20 based on the obtained printing image data Dp.

  In this way, the thickness of the ink layer after printing can be suppressed even in the input image data D where the first color image I1 and the second color image I2 overlap. Therefore, it can suppress more that an ink peels at the time of heat seal processing or after heat seal processing.

  Further, the detailed shape of the printing apparatus may be different from those in the drawings of the present application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Packaging apparatus 8 Container sheet 9 Base material 10 Conveying mechanism 11 Unwinding part 12 Conveying roller 13 Winding part 14 Nip roller 20 Inkjet printing part 21-24 Head unit 30 Light irradiation part for thickening 40 Light irradiation part for fixing DESCRIPTION OF SYMBOLS 50 Control part 51 Processing condition acquisition part 52 Film thickness range determination part 53 Print instruction | indication part 61 Container sheet supply part 62 Base material supply part 63 Heat seal part 64 Product collection part 100 PTP packaging D Image data H Processing conditions P Pressure T Temperature R Allowable range M1 Upper limit M2 Lower limit TD Table data

Claims (13)

A printing apparatus that prints an image by an inkjet method on the surface of a base material for PTP packaging that is heat-sealed in a subsequent process,
A transport mechanism for transporting the base material along a predetermined transport path;
An ink jet printing unit that ejects ink droplets toward the surface of the base material transported by the transport mechanism;
A control unit for controlling the transport mechanism and the inkjet printing unit;
With
The controller is
A processing condition acquisition unit for acquiring processing conditions of the heat seal processing;
Based on the processing conditions acquired by the processing condition acquisition unit, a film thickness range determination unit that determines an allowable range of the film thickness of the ink layer formed on the surface of the substrate;
A print instruction unit for controlling the inkjet printing unit so that the film thickness of the ink layer falls within the allowable range;
Having a printing device. The printing apparatus according to claim 1,
The processing condition includes a printing apparatus including temperature information of the heat seal processing. The printing apparatus according to claim 1 or 2, wherein
The processing condition includes a printing apparatus including pressure information of the heat seal processing. A printing apparatus according to any one of claims 1 to 3, wherein
The said film thickness range determination part is a printing apparatus which determines the upper limit of the said tolerance | permissible_range based on the said process conditions. The printing apparatus according to claim 4,
The said film thickness range determination part is a printing apparatus which makes the said upper limit the value of 3.5 micrometers or more and 8.0 micrometers or less. The printing apparatus according to claim 4 or 5, wherein:
The said film thickness range determination part is a printing apparatus which further determines the lower limit of the said tolerance | permissible_range. The printing apparatus according to any one of claims 1 to 6, wherein
The printing instruction unit corrects the density value of image data to be printed according to the allowable range. The printing apparatus according to any one of claims 1 to 6, wherein
The printing instruction unit is a printing apparatus that changes a size of an ink droplet ejected from the inkjet printing unit according to the allowable range. The printing apparatus according to any one of claims 1 to 6, wherein
The printing instruction unit adjusts the temperature of the inkjet printing unit according to the allowable range. A printing apparatus according to any one of claims 1 to 9, wherein
The control unit converts input image data composed of a first color image and a second color image arranged in front of the first color image into an overlapping portion from the first color image to the second color image. A printing apparatus that converts print image data composed of the extracted image and the second color image, and controls the inkjet printing unit based on the print image data. A printing method for printing an image by an inkjet method on the surface of the base material while transporting a base material for PTP packaging in which heat sealing is performed in a subsequent process,
a) obtaining the processing conditions of the heat sealing process;
b) determining an allowable range of the thickness of the ink layer formed on the surface of the substrate based on the processing conditions;
c) ejecting ink droplets toward the surface of the substrate such that the thickness of the ink layer falls within the allowable range;
A printing method.   A substrate for PTP packaging, on which an image is printed by the printing method according to claim 11. A substrate according to claim 12,
The base material whose film thickness of the said ink layer is 2.0 micrometers or more and 8.0 micrometers or less.

Images