WO2021117650A1 - Printing device and method, and method for producing printed work - Google Patents

Abstract

Provided are a printing device and method, and a method for producing a printed work, with which changes in color are minimized and an image having stable color can be obtained in roll-to-roll inkjet printing in which lifted conveyance is performed. A printing device (10) according to one aspect of the present disclosure comprises an unwinding section (20) that unwinds a web-form base material (12), a non-contact conveying section that lifts and conveys the base material (12) by blowing out a gas onto the base material (12) that has been unwound from the unwinding section (20), an inkjet printing section that discharges ink to print an image on the base material (12) that has passed through the non-contact conveying section, a winding section (90) that winds the base material (12) on which the inkjet printing section has printed, and a temperature adjustment device that performs temperature control to keep variation of the temperature of the gas blown out from the non-contact conveying section to a range within ±4°C.

Description

Printing equipment and methods and printed matter manufacturing methods

The present invention relates to a printing apparatus and method, and a printed matter manufacturing method, and particularly relates to a printing technique for performing inkjet printing on a substrate by a roll-to-roll method.

Patent Document 1 and Patent Document 2 describe a printing apparatus that performs inkjet printing on a base material for flexible packaging conveyed by a roll-to-roll method. In roll-to-roll transfer, when the direction of bending the transfer path of the base material toward the print surface side of the base material is changed by avoiding contact between the printed surface of the base material and the roller for transfer, wind is blown from the roller surface. There is known a technique of blowing out and transporting the base material in a state of floating from the roller surface. In this specification, the technique of performing non-contact transportation by floating the base material by the force of wind is described as "floating transportation".

Patent Document 3-4 describes a configuration in which floating transfer is performed in a roll-to-roll method.

Japanese Unexamined Patent Publication No. 2019-55570 JP-A-2019-147320 JP-A-2019-119609 Japanese Unexamined Patent Publication No. 2017-185666

In the field of flexible packaging printing, so-called "back printing" printing may be performed in which an image printed on the printed surface of a transparent substrate is visually recognized through the substrate from the surface opposite to the printed surface. When flexible packaging back printing is performed using an inkjet printing apparatus, if the rollers come into contact with the printing surface of the base material before inkjet printing, there is a concern that the printing surface may be scratched and the print image quality may be disturbed.

In addition, when the undercoat liquid is applied to the printing surface of the base material before inkjet printing, if the roller comes into contact with the printing surface to which the undercoat liquid is applied, there is a concern that the undercoat liquid will be transferred from the base material to the rollers. Will be done.

Therefore, it is desirable to transport the base material and perform inkjet printing without bringing the transport roller into contact with the printing surface of the base material on which inkjet printing is performed. When the direction of the transfer path of the base material is changed to the direction of the printing surface side, the transfer direction of the base material can be bent in any direction without contact by adopting a floating transfer device such as an air turn bar.

On the other hand, in the floating transport, the base material is exposed to wind, so the temperature of the base material changes depending on the temperature of this wind. In inkjet printing, when the temperature of the base material during printing changes, the spread of ink dots adhering to the base material changes, and the tint of the printed color changes. When such a change in color occurs, the color of the printed image will be slightly different even if the same image is printed.

In Patent Document 1-4, although there is a description about the configuration for performing floating transport, there is no description about the variation in temperature of the wind applied to the base material in the floating transport before printing (hereinafter referred to as "floating transport wind"). .. Further, Patent Document 1-4 does not describe the problem of the color change of the printed matter due to the change in the temperature of the floating transport wind in the floating transport before printing.

The present invention has been made in view of such circumstances, and is a printing apparatus capable of suppressing a change in color to obtain a stable color image in roll-to-roll inkjet printing in which floating transfer is performed. It is an object of the present invention to provide a method as well as a method for producing printed matter.

The printing apparatus according to one aspect of the present disclosure floats and conveys the base material by blowing gas onto the unwinding portion that unwinds the web-shaped base material and the base material unwound from the unwinding portion. A non-contact transport unit, an inkjet printing unit that ejects ink to a base material that has passed through the non-contact transport unit to print an image, and a winding unit that winds up the base material printed by the inkjet printing unit. A temperature control device for controlling the temperature of the gas blown out from the contact transfer unit within a range of ± 4 ° C. is provided.

According to this aspect, the temperature variation of the gas blown out to the base material is suppressed in the non-contact transport part upstream of the inkjet printing part in the transport path of the base material, so that the base material in the inkjet printing part The variation in the temperature of the base material when applying ink to the printing sheet is suppressed. As a result, the spread of the ink dots on the base material is stabilized, the change in color due to the change in temperature is suppressed, and an image with stable color can be obtained. The gas blown out to the base material by the non-contact transport unit may be paraphrased as "floating transport wind". The descriptions such as "floating transport wind" and "wind" mean the flow of gas, and the type of gas is not limited to air unless otherwise specified.

The temperature of the gas blown out from the non-contact transport section is preferably equal to or lower than the temperature of the ink ejected from the inkjet printing section. According to this aspect, it is possible to suppress ink ejection defects caused by dew condensation on the print head (inkjet head) that ejects ink, and it is possible to suppress the occurrence of image defects due to dew condensation.

In another aspect of the present disclosure, a precoat portion for applying the undercoat liquid to the base material is further provided, and the precoat part is arranged at a position upstream of the position of the inkjet printing part in the transport path of the base material. be able to. By using the undercoat liquid, it is possible to suppress the spread and / or movement of ink dots on the base material.

In still another aspect of the present disclosure, the precoat portion may be arranged at a position upstream of the position of the non-contact transport portion in the transport path of the base material. According to this aspect, since the base material to which the undercoat liquid is applied is conveyed without contact, there is no concern that the undercoat liquid is transferred from the base material to a roller or the like, and high quality printing is possible.

In still another aspect of the present disclosure, the precoat drying section further comprises a precoat drying section for drying the undercoat liquid applied to the substrate, and the precoat drying section is between the precoat section and the non-contact transport section in the transport path of the substrate. It can be configured to be placed at a position. The pre-coated drying portion may have, for example, a configuration in which warm air is blown to the base material.

The undercoat liquid can be configured to contain a component that aggregates or insolubilizes the color material component in the ink or thickens the ink by reacting with the ink. The reaction rate between the ink and the undercoat liquid is stabilized by suppressing the variation in the temperature of the gas applied to the base material to which the undercoat liquid is applied.

In still another aspect of the present disclosure, the temperature controller comprises a temperature sensor for detecting the temperature of the gas, a heater for heating the gas, a cooling device for cooling the gas, and a heater and a cooling device based on a signal from the temperature sensor. It can be configured to include a controller that controls the temperature.

In still another aspect of the present disclosure, a gas supply pipe for supplying gas to the non-contact transport portion may be further provided, and the heater and the cooling device may be arranged in the gas supply pipe.

The gas blown out to the base material in the non-contact transport section may be air.

The non-contact transfer unit can be configured to change the direction of the transfer path of the base material toward the printing surface side of the base material.

The base material may be a non-permeable film base material.

The inkjet printing unit can be configured to include a plurality of inkjet heads that eject each of a plurality of colors of ink.

The inkjet printing unit can be configured to include an inkjet head that ejects white ink. According to such an aspect, back printing can be performed on a transparent base material, and a white background can be printed with white ink.

In the printing method according to another aspect of the present disclosure, the web-like base material is unwound from the unwinding roll, and the base material is levitated by blowing gas onto the base material unwound from the unwinding roll. The non-contact transfer is performed, ink is ejected from the inkjet head to the substrate that has passed through the non-contact transfer portion in the transfer path of the substrate to perform printing, and the substrate printed by the inkjet head is printed. This includes winding the ink on a winding roll and controlling the temperature so that the temperature variation of the gas applied to the substrate during non-contact transportation is within ± 4 ° C.

In the printed matter manufacturing method according to another aspect of the present disclosure, the base material is transported by a roll-to-roll method, and the base material is levitated by blowing gas to the base material in a part of the transport path of the base material. Ink is ejected from the inkjet head to the substrate that has passed through the non-contact transport portion in the transport path of the substrate for printing, and the substrate is hit against the substrate during non-contact transport. Includes temperature control to keep the temperature variation of the gas within ± 4 ° C.

According to the printed matter manufacturing method according to this aspect, the change in the color of the printed image is suppressed, and the printed matter of the image having a stable color can be manufactured.

The base material to be printed may be a transparent film base material used for flexible packaging.

According to the present invention, a change in color tint in inkjet printing is suppressed, and a stable tint image can be obtained.

FIG. 1 is a diagram schematically showing a configuration of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a graph showing data showing the amount of change in color between the color at 25 ° C. and the color at each temperature, and an approximate curve thereof. FIG. 3 is a graph showing changes in the tint of each of the black, cyan, magenta, and yellow colors depending on the substrate temperature. FIG. 4 is a graph showing changes in the tint of each of the red, green, and blue colors depending on the substrate temperature. FIG. 5 is a graph showing the experimental results of investigating the relationship between the substrate temperature and the single streaks caused by dew condensation. FIG. 6 is a perspective view schematically showing a configuration example of the non-contact transport unit. FIG. 7 is a cross-sectional view schematically showing a configuration example of a temperature control device used for temperature control of a floating transport wind. FIG. 8 is a flowchart showing an example of a method of controlling the floating transport wind. FIG. 9 is a block diagram showing an electrical configuration of the printing apparatus. FIG. 10 is a block diagram showing the functions of the transport control unit. FIG. 11 is a flowchart showing an example of a printed matter manufacturing method according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< Configuration example of printing device >>
FIG. 1 is a diagram schematically showing a configuration of a printing apparatus 10 according to an embodiment of the present invention. The printing device 10 is a roll-to-roll inkjet printing device that prints an image on a web-shaped base material 12 by a single-pass method. The base material 12 is a non-penetrating medium, for example, a transparent film base material used for flexible packaging. Here, the term "non-penetrating" means having non-penetration with respect to a water-based primer and a water-based ink described later. Flexible packaging refers to packaging made of a material that deforms depending on the shape of the article to be packaged. Transparency means that the transmittance of visible light is 30% or more and 100% or less, and preferably 70% or more and 100% or less. The base material 12 may be, for example, ONY (Oriented Nylon), OPP (Oriented Poly Propylene), PET (Polyethylene Terephthalate), or the like.

The printing device 10 manufactures a back-printed printed matter in which a printed image can be visually recognized from the surface of the base material 12 opposite to the printing surface. The direction indicated by the arrow A in FIG. 1 indicates the observation direction of the printed image by the user. The printing surface of the base material 12 means a base material surface to which ink is applied by inkjet printing. The printed matter produced by using the printing apparatus 10 according to the present embodiment is a printed matter in which a printed image is observed from the side of the non-printed surface, which is the side opposite to the printed surface.

The printing apparatus 10 includes an unwinding section 20, a precoat section 30, a precoat drying section 34, a first non-contact transport section 40, a first suction drum 50, a jetting section 60, and a second suction drum 70. , The second non-contact transport unit 80 and the winding unit 90 are included. The transport path of the base material 12 from the unwinding portion 20 to the take-up portion 90 is referred to as a “base material transport route”. The transport direction of the base material 12 along the base material transport path is referred to as a “base material transport direction”. Regarding the base material transport path, the "upstream side" means the side close to the unwinding portion 20, and the "downstream side" means the side close to the winding portion 90.

Along the substrate transfer path from the unwinding section 20, the precoat section 30, the precoat drying section 34, the first non-contact transport section 40, the first suction drum 50, the jetting section 60, the second suction drum 70, and the second none. The contact transport section 80 and the take-up section 90 are arranged in this order.

The base material transport mechanism 100 that transports the base material 12 unwound from the unwinding portion 20 to the take-up portion 90 along the base material transport path includes a first non-contact transport unit 40, a first suction drum 50, and a second. It is a roll-to-roll transfer mechanism including a suction drum 70 and a second non-contact transfer unit 80. The unwinding unit 20 and the winding unit 90 may be included in the base material transport mechanism 100. Further, in addition to the configuration shown in FIG. 1, the base material transport mechanism 100 includes one or more elements such as a pass roller (not shown), a drive roller (not shown), and a non-contact transport portion that function as guide rollers. You may. The base material transport mechanism 100 can transport the base material 12 at a constant transport speed.

The unwinding roll 22 is arranged in the unwinding portion 20. The unprinting roll 22 is a roll in which the (unprinted) base material 12 before printing is wound in a roll shape. The unwinding portion 20 includes an undrawing device (not shown) that rotatably supports the core 23 of the unwinding roll 22, and the base material 12 is unwound from the unwinding roll 22.

A take-up roll 92 is arranged in the take-up unit 90. The take-up roll 92 is a roll in which the printed base material 12 printed by the jetting unit 60 is wound into a roll shape. The take-up unit 90 includes a take-up device (not shown), and one end of a base material 12 unwound from the take-up unit 20 is connected to a take-up reel (not shown) held by the take-up device. The take-up device includes a take-up motor (not shown) that rotationally drives the take-up reel. By rotating the take-up reel, the base material 12 is taken up by the take-up roll 92.

The printing apparatus 10 employs a two-component configuration in which the precoating unit 30 applies an undercoating liquid to the base material 12 and then performs inkjet printing before the inkjet printing in the jetting unit 60. That is, the precoat portion 30 is arranged on the upstream side of the base material transport path with respect to the jetting portion 60. By using the ink composition and the undercoat liquid, inkjet printing can be speeded up, and even when printing at high speed, an image having high density and high resolution and excellent reproducibility of fine lines and fine portions can be obtained. In this embodiment, a water-based ink is used in inkjet printing, and a water-based primer is used as an undercoat liquid.

The precoat portion 30 applies an aqueous primer to the printed surface of the base material 12. The water-based primer contains water and a component that aggregates or insolubilizes the color material component in the water-based ink or thickens the ink. The amount of the water-based primer applied is, for example, about 1/10 of the amount of the water-based ink applied by the jetting unit 60. The viscosity of the aqueous primer is, for example, 0.5 cP or more and 5.0 cP or less. In addition, 1 cP (centipores) is 0.001 Pa · s (Pascal second).

For the precoat portion 30, for example, a chamber doctor type coater is used. The coater includes a coating roller 32, a chamber (not shown), and a blade (not shown). The chamber is a container for storing aqueous primers. The coating roller 32 is rotated by a motor (not shown). An aqueous primer is supplied from the chamber to the surface of the coating roller 32. The blade scrapes off excess aqueous primer on the surface of the rotating coating roller 32. The coating roller 32 sandwiches the base material 12 with an opposing roller (not shown) and brings the roller surface to which the water-based primer is supplied into contact with the printing surface of the base material 12, so that the water-based primer is printed on the base material 12. Apply to the surface.

The coater is not limited to the chamber doctor type coater, and a direct gravure coater or a kiss reverse coater may be applied. Further, the method of applying the undercoat liquid is not limited to the roller coating method, and an inkjet method may be adopted.

The precoat drying section 34 performs a process of drying the aqueous primer applied to the printed surface of the base material 12 by the precoat section 30. The precoat drying unit 34 includes a hot air heater (not shown). The hot air heater has, for example, a slit nozzle (not shown) over the entire width of the base material 12. The precoat drying unit 34 blows warm air from the slit nozzle of the warm air heater toward the printed surface of the base material 12 to dry the aqueous primer.

The base material 12 on which the aqueous primer has been dried is conveyed to the jetting unit 60 via the first non-contact transfer unit 40 and the first suction drum 50.

The first non-contact transport unit 40 blows air to the base material 12 to carry out floating transport, and the traveling direction of the base material 12 is set to the print surface side of the base material 12 without contacting the print surface of the base material 12. Performs a direction change to bend in the direction of. The first non-contact transport unit 40 shown in FIG. 1 shows an example in which the traveling direction of the base material 12 horizontally transported in the precoat drying unit 34 is turned upward by 90 degrees, but the angle of direction change is 90 degrees. Not limited to this, any angle of 180 degrees or less can be set at an angle exceeding 0 degrees. Details of the first non-contact transport unit 40 will be described later.

The base material 12 whose traveling direction of the base material 12 is bent by the first non-contact transport unit 40 is transported to the first suction drum 50. The first suction drum 50 is arranged on the upstream side of the base material transport path with respect to the jetting portion 60.

The first suction drum 50 is rotated by a motor (not shown), and the base material 12 is attracted to the outer peripheral surface of the drum and conveyed. The first suction drum 50 has a plurality of suction holes (not shown) on the outer peripheral surface of the drum. The first suction drum 50 attracts the base material 12 to the outer peripheral surface of the drum by sucking the suction holes by a pump (not shown).

The base material 12 conveyed by the first suction drum 50 is conveyed to the second suction drum 70. The configuration of the second suction drum 70 is the same as that of the first suction drum 50. By giving a rotational speed difference between the rotational speed of the second suction drum 70 and the rotational speed of a drive roller (not shown), a transfer tension can be applied to the base material 12. The transport tension is a tensile force that the base material 12 receives in the traveling direction of the base material 12.

The jetting unit 60 is arranged in the base material transport path between the first suction drum 50 and the second suction drum 70. The jetting unit 60 includes inkjet heads 62K, 62C, 62M, 62Y, and 62W. The jetting unit 60 is an example of the “inkjet printing unit” in the present disclosure. The inkjet heads 62K, 62C, 62M, 62Y, and 62W are print heads that eject black (K), cyan (C), magenta (M), yellow (Y), and white (W) water-based inks, respectively.

Aqueous ink refers to an ink in which a coloring material such as a dye or a pigment is dissolved or dispersed in water and a solvent soluble in water. In this embodiment, a water-based pigment ink is used. Organic pigments are used as pigments for each of the CMYK water-based inks. Titanium oxide is used as the pigment for the water-based white ink. The viscosity of each water-based ink is 0.5 cP or more and 5.0 cP or less. The water-based ink thickens by reacting with the water-based primer.

Water-based ink is supplied to each of the inkjet heads 62K, 62C, 62M, 62Y, and 62W from an ink tank of a corresponding color (not shown) via a piping path (not shown). Each of the ink supply systems of the inkjet heads 62K, 62C, 62M, 62Y, and 62W is provided with an ink temperature adjusting device (not shown) for maintaining the ink temperature at a specified ink temperature. The ink temperature control device includes a temperature sensor (not shown) that detects the ink temperature, a heater (not shown) that heats the ink, and a controller (not shown) that controls the heater based on the detection signal of the temperature sensor.

The inkjet heads 62K, 62C, 62M, 62Y, and 62W are line-type print heads that can be printed by one scan on the base material 12 transported by the base material transport mechanism 100.

A plurality of nozzles, which are ink ejection ports, are two-dimensionally arranged on each nozzle surface of the inkjet heads 62K, 62C, 62M, 62Y, and 62W. The nozzle surface refers to the discharge surface on which the nozzle is formed. A water-repellent film is formed on each nozzle surface of the inkjet heads 62K, 62C, 62M, 62Y, and 62W.

The inkjet heads 62K, 62C, 62M, 62Y, and 62W can each be configured by connecting a plurality of head modules in the width direction of the base material 12.

Ink droplets are ejected from at least one of the inkjet heads 62K, 62C, 62M, 62Y, and 62W toward the printing surface of the substrate 12 conveyed by the substrate transfer mechanism 100, and the ejected droplets are discharged. By adhering to the base material 12, an image is printed on the printed surface of the base material 12. The ink applied to the printed surface of the base material 12 in the jetting portion 60 undergoes a condensation thickening reaction by the aqueous primer applied to the printed surface of the base material 12 in the precoat portion 30.

Although the configuration using KSMY's four color inks (non-white ink) and white (white) ink is shown here, the ink color and the number of colors are not limited to this embodiment. For example, an inkjet head that ejects light color inks such as light magenta and light cyan, special color inks such as green, orange, and violet, clear ink, and metallic ink may be added. Further, a plurality of inkjet heads that eject ink of the same color may be arranged. The arrangement order of the inkjet heads of each color is not particularly limited, but since the white ink is used when printing a white background image, the inkjet head 62W is located downstream of the inkjet head that ejects the non-white ink. It is preferable to be arranged.

The second non-contact transport section 80 is arranged in the substrate transport path between the second suction drum 70 and the take-up section 90. The configuration of the second non-contact transport unit 80 is the same as that of the first non-contact transport unit 40.

<< About the temperature of the wind blown from the first non-contact transport unit 40 >>
It has been found from market research that flexible packaging is extremely sensitive to changes in the color of printed matter. Therefore, it is required to suppress the change in the color of the printed matter within the required allowable range. Specifically, if the amount of change in color, ΔE, satisfies ΔE ≦ 2, it is considered that the demands of the market can be met. ΔE is a color difference in the CIE L * a * b * (CIELAB) color space defined by the Commission internationale de l'eclairage (CIE).

[Relationship between substrate temperature and color change]
2 to 4 are graphs showing the experimental results of investigating the relationship between the substrate temperature and the amount of change in color. In the experiment, the base material temperature was shaken from 25 ° C. to 40 ° C., a chart in which the print density at each temperature was changed was printed, and the rate of change (inclination) of the color tone with respect to the temperature was obtained from the amount of change in the color tone due to the temperature. It was. The conditions of the base material, undercoat liquid, ink, ink temperature, and base material standard temperature used in the experiment are as follows.

<Experimental conditions>
・ Base material: Carta Integra 265gsm
・ Undercoat liquid: FUJIFILM preconditioning liquid C-FJ-CP3
・ Ink: Aqueous pigment ink for inkjet manufactured by FUJIFILM Corporation
・ Ink temperature: 30 ℃
・ Base material standard temperature: 30 ℃
FIG. 2 is a graph showing data showing the amount of change in color between the color at the lowest temperature (25 ° C. in this case) and the color at each temperature, and an approximate curve thereof. The horizontal axis represents the temperature, and the vertical axis represents the color difference ΔE. FIG. 3 is a graph showing changes in the tint of each of the black, cyan, magenta, and yellow colors depending on the substrate temperature. FIG. 4 is a graph showing changes in the tint of each of the red, green, and blue colors depending on the substrate temperature. In FIGS. 3 and 4, the horizontal axis represents the print density, and the vertical axis represents the amount of color change (ΔE / ΔT) per unit temperature. ΔE / ΔT is called "the slope of color with respect to temperature". The print density on the horizontal axis is represented by the halftone dot area ratio.

From FIGS. 3 and 4, it can be seen that the maximum value of the slope of the tint with respect to temperature is 0.25 or less. Therefore, in order to keep the color change within ΔE ≦ 2, the amount of temperature change of the base material needs to be within 2 / 0.25 = 8 [° C.]. This means that the temperature variation of the base material must be kept within ± 4 ° C.

Even when the same experiment was carried out by changing the type of the base material used, the results shown in FIGS. 2 to 4 were almost the same for various non-penetrating media.

Since the base material 12 used for flexible packaging is generally an extremely thin base material having a thickness of about 20 μm to 25 μm, the temperature of the base material 12 at the time of printing is used for floating transportation of the first non-contact transport unit 40. It is considered that the temperature of the wind applied to the base material 12 can be easily followed.

Therefore, in order to keep the color change of the printed matter within ΔE ≦ 2, it is necessary to suppress the variation in the temperature of the wind applied to the base material 12 by the floating transport in the first non-contact transport unit 40 within a range of ± 4 ° C. is necessary. In the printing apparatus 10 according to the present embodiment, assuming that the temperature of the wind applied to the base material 12 by the first non-contact transport unit 40 is T1 [° C.] and the target temperature in temperature control is Tgt [° C.], the temperature T1 is Tgt. Control within a temperature range of ± 4 ° C. The target temperature Tgt is preferably set to a value lower than the temperature of the ink ejected from the inkjet head by the jetting unit 60.

[Relationship between ink temperature and floating transport air temperature]
FIG. 5 is a graph showing the experimental results of investigating the relationship between the substrate temperature and the single streaks caused by dew condensation. Single-shot streaks are streak-like image defects that occur in printed matter due to poor nozzle ejection. The single-shot streak caused by dew condensation means a single-shot streak caused by a nozzle ejection failure caused by dew condensation on the nozzle surface of the print head.

The horizontal axis of FIG. 5 represents the base material temperature, and the vertical axis represents the number of single streaks caused by dew condensation by the number of streaks generated per 100 sheets. The environment in which the experiment was carried out was a temperature of 28 ° C., a humidity of 60% RH, and an ink temperature of 30 ° C. The ink temperature is the temperature of the ink discharged from the print head, and may be understood as the temperature of the nozzle surface. As the ink, black ink (P20K), which is a water-based pigment ink, was used.

According to the graph shown in FIG. 5, when the base material temperature is 32 ° C. or lower with respect to the ink temperature of 30 ° C., no single streak is generated, whereas when the base material temperature exceeds 33 ° C. The frequency of single-shot streaks increases sharply. It is understood that the temperature of the base material during inkjet printing is similar to the temperature of the wind applied to the base material during floating transportation before inkjet printing. Therefore, from the viewpoint of suppressing the generation of single streaks caused by dew condensation, the preferable temperature condition of the floating transport wind is equal to or lower than the ink temperature in view of the margin. That is, it is preferable that Tgt + 4 ° C., which is the upper limit temperature of the temperature range of the floating transport wind in the first non-contact transport unit 40, is equal to or lower than the ink temperature.

<< Configuration example of non-contact transport unit >>
FIG. 6 is a perspective view schematically showing a configuration example of the non-contact transport unit. Here, an example of a 180-degree turn bar that changes the direction of the base material transport path to a U-shape by 180 degrees is shown, but the basic structure is the same for a turn bar that changes the direction to another angle such as a 90-degree turn bar. Each of the first non-contact transport unit 40 and the second non-contact transport unit 80 may adopt substantially the same configuration. Here, the first non-contact transport unit 40 will be described.

The first non-contact transport unit 40 includes a turn bar 42. The turn bar 42 includes a transport plate 44 having a U-shaped curved surface along a substrate transport path, two side plates 45 and 45 covering both side surfaces of the transport plate 44 in the width direction, and a rear portion of the transport plate 44. Includes a back plate 46 that covers (the upper end portion in FIG. 2).

The transport plate 44 includes a curved surface portion 44A curved in an arc shape and a flat surface portion 44B extending from both ends of the arc of the curved surface portion 44A. A plurality of outlets 48 for blowing air to the base material 12 are arranged on the curved surface portion 44A and the flat surface portion 44B of the transport plate 44. The outlet 48 may be a circular through hole. The outlets 48 are arranged in a staggered pattern in the plane of the transport plate 44 at predetermined pitches in the base material width direction and the base material transport direction and directions orthogonal to the base material transport direction. The pitch of the outlet 48 is preferably set according to the hole diameter of the outlet 48.

The inside of the turn bar 42 is divided into a plurality of rooms 412A, 412B, and 412C by partition plates 410 and 410, and the air flow between the rooms is blocked. FIG. 6 shows an example in which two partition plates 410 and 410 are used to divide the turn bar 42 into three rooms 412A, 412B, and 412C at equal intervals in the width direction. Not limited to this, an appropriate configuration can be adopted.

Air supply pipes 414A, 414B, and 414C that supply air to each of the plurality of rooms 412A, 412B, and 412C are connected to the back plate 46. A blower (not shown) is connected to the air supply pipes 414A, 414B, and 414C. As the turn bar 42, for example, an air turn bar TBA or TBE manufactured by BELLMATIC Co., Ltd. can be used.

The air supplied to the turn bar 42 via the air supply pipes 414A, 414B, and 414C is blown out from the outlet 48. In the present embodiment, the variation in the temperature of the air blown from the outlet 48 is controlled within ± 4 ° C.

The base material 12 floats from the transport plate 44 by the air blown from the outlet 48, and is floated and transported to the turn bar 42 without contact. The term levitation transport is synonymous with levitation transport, non-contact transport, or air float transport. The air supply pipes 414A, 414B, and 414C are examples of the "gas supply pipes" in the present disclosure.

FIG. 7 is a cross-sectional view schematically showing a configuration example of the temperature control device 440 used for temperature control of the floating transport wind. The temperature control device 440 includes a temperature sensor 442, a heater 444, a Peltier element 446, and a controller 448. The temperature sensor 442, the heater 444, and the Peltier element 446 are connected to the controller 448.

The temperature sensor 442 may be, for example, a thermocouple. The temperature sensor 442 is arranged inside the turn bar 42 and detects the temperature of the air blown out from the outlet 48. The controller 448 includes a temperature measuring device 449 that measures the temperature of the floating transport air based on the signal obtained from the temperature sensor 442. The temperature measuring device 449 may include a display for displaying information on the measured temperature.

The controller 448 operates the heater 444 and the Peltier element 446 so that the temperature of the floating transport air is within the specified temperature range. The controller 448 includes, for example, a processor such as a CPU (Central Processing Unit).

The heater 444 and the Peltier element 446 are arranged in the air supply pipe 414. The air supply pipe 414 represents the air supply pipes 414A, 414B, and 414C shown in FIG. A heater 444 and a Peltier element 446 are arranged in each of the plurality of air supply pipes 414A, 414B, and 414C. The heater 444 is an example of a heating device that heats air to raise the temperature of the floating transport air. The heater 444 is ON / OFF controlled by the controller 448. The Peltier element 446 is an example of a cooling device that cools air to lower the temperature of the floating transport air.

The controller 448 controls the temperature of the floating transport air to a temperature equal to or lower than the ink temperature, and controls the temperature so that the temperature variation is within ± 4 ° C. For example, when the ink temperature is set to 30 ° C., the controller 448 controls the temperature of the floating transport air within the range of 26 ° C. ± 4 ° C. That is, the temperature of the floating transport air is controlled so that the maximum value in the allowable range of temperature variation of ± 4 ° C. is equal to or lower than the ink temperature.

A precoat layer 33 is formed on the printed surface of the base material 12. According to the first non-contact transport unit 40, the base material 12 can be transported without bringing the precoat layer 33 into contact with the transport plate 44. The first non-contact transport unit 40 is an example of the “contactless transport unit” in the present disclosure.

<< Example of control method of floating transport wind >>
FIG. 8 is a flowchart showing an example of a method of controlling the floating transport wind. The steps in the flowchart shown in FIG. 8 are performed by the controller 448.

In step S11, the controller 448 starts blowing the floating transport air. The controller 448 opens an air supply valve (not shown), starts supplying air to the turn bar 42 via the air supply pipe 414, and blows out air from the outlet 48.

In step S12, the controller 448 turns on the power of the heater 444. Further, in step S13, the controller 448 turns on the power of the temperature measuring device 449. After that, the temperature measurement by the temperature measuring device 449 is continued, and the controller 448 constantly monitors the temperature of the floating transport air.

In step S14, the controller 448 determines whether or not printing by the printing device 10 is possible. This determination process is performed based on the flag set in step S16 or step S18, which will be described later. The printable state is called the "print OK" state, and the non-printable state is called the "print NG" state. In the initial state immediately after the start of control, it is assumed that the state is "printing NG".

When the determination result in step S14 is No, that is, when the printing device 10 is in the printing NG state, the controller 448 proceeds to step S15.

In step S15, the controller 448 determines whether or not the temperature of the floating transport air is the printable temperature. The printable temperature is specified, for example, in the temperature range of 26 ° C. ± 4 ° C. If the determination result in step S15 is No, the controller 448 proceeds to step S20.

If the determination result in step S15 is Yes determination, the controller 448 proceeds to step S16. In step S16, the controller 448 sets a flag indicating that the printing device 10 is in the printing OK state. The state in which the print OK flag is set indicates that the printing device 10 is permitted to execute printing. After step S16, controller 448 proceeds to step S20. When the print is OK, the print job is executed and printing is performed.

If the determination result in step S14 is Yes determination, the controller 448 proceeds to step S17. In step S17, the controller 448 determines whether or not the temperature of the floating transport air is a non-printable temperature. The non-printable temperature means that the temperature is not the printable temperature, that is, the temperature is out of the printable temperature range.

In step S17, the controller 448 determines whether or not the temperature of the floating transport air is a non-printable temperature. The non-printable temperature is specified, for example, in the temperature range of 26 ° C. ± 4 ° C. When the determination result in step S17 is Yes determination, that is, when the temperature of the floating transport air is the non-printable temperature, the controller 448 proceeds to step S18.

In step S18, the controller 448 sets a flag indicating that the printing device 10 is in the printing NG state. The state in which the print NG flag is set indicates that the printing device 10 is prohibited from executing printing. After step S18, controller 448 proceeds to step S20.

If the determination result in step S17 is No, the controller 448 proceeds to step S20.

In step S20, the controller 448 determines whether or not the heater power supply is in the ON state. If the determination result in step S20 is Yes determination, the controller 448 proceeds to step S21 to determine whether or not the temperature of the floating transport air is equal to or higher than the designated upper limit temperature. The designated upper limit temperature is set to a temperature indicating the upper limit of the temperature range designated as the printable temperature, or a temperature slightly lower than this.

If the determination result in step S21 is No, the controller 448 returns to step S14.

If the determination result in step S21 is Yes determination, the controller 448 proceeds to step S22, turns off the power of the heater 444, and turns on the power of the Peltier element 446. After step S22, controller 448 returns to step S14.

If the determination result in step S20 is No, the controller 448 proceeds to step S23 and determines whether or not the temperature of the floating transport air is equal to or lower than the specified lower limit temperature. The designated lower limit temperature is set to a temperature indicating the lower limit of the temperature range designated as the printable temperature, or a temperature slightly higher than this.

If the determination result in step S23 is No, the controller 448 returns to step S14.

If the determination result in step S23 is Yes determination, the controller 448 proceeds to step S24, turns on the power of the heater 444, and turns off the power of the Peltier element 446. After step S24, controller 448 returns to step S14.

By continuously executing the control shown in FIG. 8 while the printing apparatus 10 is in operation, it is possible to keep the temperature variation of the floating transport air during printing within ± 4 ° C.

<< Explanation of the control system of the printing device 10 >>
FIG. 9 is a block diagram showing an electrical configuration of the printing apparatus 10. The printing device 10 includes a communication unit 202, a user interface 204, a storage unit 206, a general control unit 210, an unwinding control unit 220, a transport control unit 222, a precoat control unit 230, and a precoat drying control unit 234. A jetting control unit 260 and a take-up control unit 290 are provided.

The communication unit 202 includes a wired or wireless communication interface. The printing device 10 can acquire image data or the like to be printed via the communication unit 202.

The user interface 204 includes an input device (not shown) and a display device (not shown) for the user to operate the printing device 10. The input device is, for example, an operation panel that receives input from a user. As the input device, various input devices such as a keyboard, a mouse, a touch panel, and a trackball can be adopted, and any combination thereof may be used. The display device is, for example, a display that displays image data and various types of information. The user can make the printing device 10 print a desired image by operating the input device.

The storage unit 206 stores a program for controlling the printing device 10 and information necessary for executing the program. The storage unit 206 is composed of a hard disk (not shown) and / or a computer-readable medium which is a non-temporary tangible object such as various semiconductor memories.

The integrated control unit 210 performs various processes according to the program stored in the storage unit 206, and controls the overall operation of the printing device 10.

The unwinding control unit 220 controls the rotation of a motor (not shown) in the unwinding unit 20, and controls the unwinding operation of the base material 12.

The transfer control unit 222 controls the operation of the base material transfer mechanism 100. The unwinding portion 20 and the winding portion 90 may be included in the base material transport mechanism 100.

The transport control unit 222 controls the rotation of a motor or the like (not shown) and rotates the base material 12 at a predetermined speed to transport the base material 12 in a roll-to-roll manner. The transport control unit 222 includes the controller 448 described with reference to FIG.

The precoat control unit 230 controls the coater of the precoat unit 30. That is, the precoat control unit 230 controls the rotation of a motor (not shown) that drives the coating roller 32, rotates the coating roller 32 at a predetermined speed, and applies the aqueous primer to the printed surface of the base material 12 by the coating roller 32. Let me.

The precoat drying control unit 234 controls the temperature and air volume of the hot air heater provided in the precoat drying unit 34 to dry the undercoat liquid on the base material 12.

The jetting control unit 260 controls the ink ejection operation of each inkjet head 62K, 62C, 62M, 62Y, 62W in the jetting unit 60 based on the print data. The jetting control unit 260 includes an image processing unit that performs various conversion processing, correction processing, halftone processing, and the like on the image data to be printed. The conversion process includes pixel number conversion, gradation conversion, color conversion, and the like. The correction process includes density correction, non-ejection correction for suppressing the visibility of image defects due to the non-ejection nozzle, and the like.

The jetting control unit 260 uses the inkjet heads 62K, 62C, 62M, and 62Y to eject droplets of black, cyan, magenta, and yellow water-based inks at the timing when the base material 12 passes through the positions facing the nozzle surfaces. Discharge toward the base material 12. As a result, a color image is printed on the printed surface of the base material 12.

The jetting control unit 260 ejects droplets of white water-based ink from the inkjet head 62W toward the base material 12 at the timing when the base material 12 passes through a position facing the nozzle surface of the inkjet head 62W. As a result, a white background image is printed on the printed surface of the base material 12. The white background image is not limited to the image printed on the entire surface of the color image area, and may be an image selectively printed with respect to the color image area.

The take-up control unit 290 controls the rotation of a motor (not shown) in the take-up unit 90, rotates the take-up roll 92, and controls the take-up operation of the base material 12.

FIG. 10 is a block diagram showing the functions of the transport control unit 222. The transfer control unit 222 includes a first non-contact transfer control unit 224, a suction drum control unit 225, and a second non-contact transfer control unit 228. The first non-contact transfer control unit 224 controls the temperature of the floating transfer air in the first non-contact transfer unit 40 and the amount of air blown out (air volume) from the outlet 48. The first non-contact transfer control unit 224 includes the controller 448 described with reference to FIG.

The suction drum control unit 225 controls the rotation speed and suction pressure of the first suction drum 50 and the second suction drum 70, respectively. The suction drum control unit 225 can function as a tension control unit that controls the transport tension of the base material 12.

The second non-contact transport control unit 228 controls the amount of air blown from the outlet of the second non-contact transport unit 80. The second non-contact transport unit 80 can be in a form in which the temperature of the wind is not controlled, and the temperature sensor 442, the heater 444, and the Peltier element 446 can be omitted.

<< Example of printed matter manufacturing method >>
FIG. 11 is a flowchart showing an example of a printed matter manufacturing method according to the embodiment of the present invention. The flowchart of FIG. 11 may be understood as an example of a printing method implemented by using the printing device 10. A printed matter can be produced by performing roll-to-roll inkjet printing using the printing apparatus 10.

In step S110, the first non-contact transfer control unit 224 sets the target temperature of the floating transfer wind. This setting may be automatically set to a value specified in advance according to the program, or may be set to a value specified by the user via the user interface 204.

The target temperature of the floating transport wind may be automatically determined based on the ink temperature at the time of printing. A permissible range of ± 4 ° C. variation is set around the specified target temperature, and a printable temperature range is set. In step S110, the setting is not limited to the configuration in which the target temperature as the reference temperature is set, and the lower limit temperature and the upper limit temperature in the allowable range of ± 4 ° C. may be set.

In step S111, the first non-contact transfer control unit 224 starts controlling the floating transfer wind. The content of the control process in step S111 may be the flowchart described with reference to FIG. The control of the floating transport wind started in step S111 is continuously executed until the printing is completed.

In step S112, the overall control unit 210 determines whether or not printing is OK. This determination process is performed based on the flag set in step S16 or step S18 of FIG. If the determination result in step S113 is No, the overall control unit 210 loops the process of step S112 and waits until the printing is OK.

If the determination result in step S112 is Yes determination, the overall control unit 210 proceeds to step S112 and executes the designated print job.

In step S113, the base material transport mechanism 100 unwinds the base material 12 from the unwinding roll 22 and transports the base material 12.

In step S114, the precoat portion 30 applies an aqueous primer to the printed surface of the base material 12.

In step S115, the precoat drying section 34 dries the aqueous primer applied to the printed surface of the base material 12.

In step S116, the first non-contact transport unit 40 blows floating transport air onto the printed surface of the base material 12 to change the direction of the base material transport path without contact.

In step S117, the first suction drum 50 attracts the base material 12 from the non-printing surface side and conveys the base material 12.

In step S118, the jetting unit 60 applies ink to the printing surface of the base material 12 and prints an image on the base material 12. The region of the base material 12 that has been inkjet printed by the jetting unit 60 is transported to the winding unit 90 via suction transfer by the second suction drum 70 and non-contact transfer by the second non-contact transfer unit 80.

After that, in step S120, the winding unit 90 winds the printed base material 12 on the winding roll 92. The printed substrate 12 is an example of the "printed matter" in the present disclosure. A step of drying the ink may be added between steps S118 and S120. For example, an ink drying section (not shown) is arranged between the second non-contact transport section 80 and the winding section 90 in the base material transport path, and the ink drying section is an ink applied to the printing surface of the base material 12. To dry.

In step S121, the overall control unit 210 determines whether or not to end printing. When printing is continued, such as when the designated print job is incomplete, the determination result in step S121 becomes a No determination, and the process returns to step S112. During the period from step S112 to step S121, the control of the floating transport wind described with reference to FIG. 8 is also executed, and the temperature variation of the floating transport wind of the first non-contact transport unit 40 at the time of printing. Is kept within ± 4 ° C.

When printing is completed, such as when the processing of the designated print job is completed, or when the unwinding roll 22 is replaced in the middle of the print job, the determination result in step S121 becomes Yes determination, and the overall control unit 210 ends the flowchart of FIG. In this way, the production of the printed matter is completed. According to the printed matter manufacturing method according to the present embodiment, a printed matter having a stable color can be obtained.

Transporting the base material 12 from the unwinding portion 20 to the winding portion 90 by the base material transporting operation including the base material unwinding operation in step S114 and the base material winding operation in step S120 is a "roll" in the present disclosure. This is an example of "transporting a base material by a two-roll method".

<< About the ejection method of the inkjet head >>
The ejector of the inkjet head includes a nozzle for discharging a liquid, a pressure chamber communicating with the nozzle, and a discharge energy generating element for supplying discharge energy to the liquid in the pressure chamber. Regarding the ejection method for ejecting droplets from the nozzle of the ejector, the means for generating the ejection energy is not limited to the piezoelectric element, and various ejection energy generating elements such as a heat generating element and an electrostatic actuator can be applied. For example, a method of ejecting droplets by utilizing the pressure of film boiling due to heating of a liquid by a heat generating element can be adopted. Depending on the ejection method of the inkjet head, a corresponding ejection energy generating element is provided in the flow path structure.

<< Example of undercoat liquid >>
The undercoat liquid may be referred to as a preconditioning liquid, a precoat liquid, a pretreatment liquid, a treatment liquid, or the like. The undercoat liquid contains, for example, at least a flocculant that agglomerates the components in the ink composition of the ink, and can be composed of other components as needed. The flocculant may be a compound capable of changing the pH of the ink composition, a polyvalent metal salt, or polyallylamines. For example, as the coagulant, an acidic substance having high water solubility can be used, and an organic acid is preferable, and a divalent or higher organic acid is more preferable, and a divalent organic acid is preferable in terms of enhancing cohesiveness and immobilizing the entire ink. Acidic substances having a valence of 3 or more and 3 or less are particularly preferable. Specifically, phosphoric acid, oxalic acid, malonic acid, citric acid and the like are preferably mentioned. The flocculant may be used alone or in combination of two or more.

The undercoat liquid can further contain other additives as other components within a range that does not impair the desired aggregation effect. Other additives include, for example, anti-drying agents (wetting agents), anti-fading agents, emulsion stabilizers, penetration promoters, UV absorbers, preservatives, fungicides, pH regulators, surface tension regulators, defoamers. Known additives such as foaming agents, viscosity regulators, dispersants, dispersion stabilizers, rust preventives, chelating agents and the like can be mentioned.

<< Hardware configuration of each processing unit and control unit >>
Communication unit 202, integrated control unit 210, unwinding control unit 220, transfer control unit 222, first non-contact transfer control unit 224, suction drum control unit 225, second non-contact transfer control unit described with reference to FIGS. 9 and 10. The hardware structure of the processing unit that executes various processes such as 228, precoat control unit 230, precoat drying control unit 234, jetting control unit 260, and take-up control unit 290 is shown below. Various processors such as.

For various processors, CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), which is a general-purpose processor that executes programs and functions as various processing units, is a processor whose circuit configuration can be changed after manufacturing. A dedicated electric circuit, which is a processor having a circuit configuration specially designed for executing a specific process such as a programmable logic device (PLD) or an ASIC (Application Specific Integrated Circuit), is included.

One processing unit may be composed of one of these various processors, or may be composed of two or more processors of the same type or different types. For example, one processing unit may be composed of a plurality of FPGAs or a combination of a CPU and an FPGA. Further, a plurality of processing units may be configured by one processor. As an example of configuring a plurality of processing units with one processor, first, one processor is configured by a combination of one or more CPUs and software, as represented by a computer such as a client or a server. There is a form in which the processor functions as a plurality of processing units. Secondly, as typified by System On Chip (SoC), there is a form that uses a processor that realizes the functions of the entire system including multiple processing units with one IC (Integrated Circuit) chip. is there. As described above, the various processing units are configured by using one or more of the above-mentioned various processors as a hardware-like structure.

Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

<< Advantages of the embodiment >>
(1) According to the present embodiment, in the inkjet printing, the variation in the temperature of the wind applied to the base material 12 in the floating transfer before the inkjet printing is performed by the jetting unit 60 is suppressed within ± 4 ° C. The change in color is suppressed, and an image with stable color that satisfies ΔE ≦ 2 can be obtained.

(2) Further, by setting the temperature of the wind applied to the base material 12 to the ink temperature or lower in the floating transfer before performing the inkjet printing, it is possible to suppress the occurrence of printing defects due to dew condensation.

(3) According to the present embodiment, the temperature of the base material 12 can be controlled without contact by controlling the temperature of the floating transport air, so that the temperature of the base material is controlled by using a contact type heating roller or the like. The temperature control followability (responsiveness) is high, and the temperature of the base material 12 can be stabilized during inkjet printing.

<< Modification 1 >>
The configuration of the printing apparatus 10 described with reference to FIG. 1 can be variously modified. For example, it is possible to include a surface modification portion that performs surface modification such as corona treatment in the substrate transport path between the unwind portion 20 and the precoat portion 30.

<< Modification 2 >>
Further, the printing apparatus 10 may include an ink drying unit and an image inspection unit between the jetting unit 60 and the winding unit 90. In this case, the printing device 10 includes an ink drying control unit (not shown) that controls the ink drying unit, and an image inspection control unit (not shown) that controls the image inspection unit. The ink drying unit includes a hot air heater that dries the ink applied to the printing surface of the base material 12. The ink drying control unit controls the temperature and air volume of the hot air heater to dry the ink on the base material 12.

The image inspection unit includes an imaging device that captures an image printed on the base material 12. The image inspection unit can read the test pattern image printed on the base material 12 and perform a process of identifying a defective nozzle from the read image. Further, the image inspection unit reads an image to be printed printed on the base material 12 and performs a print image inspection process for inspecting whether or not there is an image defect such as a streak in the image based on the read image. be able to. The "printable image" here refers to an image corresponding to the image data for printing specified in the print job, and refers to an image for printing purposes specified by the user. The image inspection control unit controls the image reading operation by the image inspection unit and processes the obtained read image.

<< Modification 3 >>
Although an example of a two-component printing apparatus 10 using an undercoat liquid has been described with reference to FIG. 1, a form in which the undercoat liquid is not used is also possible, and a configuration in which the precoat portion 30 is omitted from the printing apparatus 10 of FIG. 1 is also possible. ..

<< Modification 4 >>
In the above-described embodiment, an example in which air is used as the floating transport wind has been described, but the type of gas blown out to the base material 12 during floating transport is not particularly limited. Instead of air, an inert gas such as nitrogen may be used.

<< Modification 5 >>
By suppressing the variation in the temperature of the floating transport wind within a range narrower than ± 4 ° C., for example, by suppressing it within ± 3 ° C., the change in color can be further suppressed.

<< Modification 6 >>
In the above-described embodiment, an example of back-printing on a transparent base material for flexible packaging has been described, but the base material may be an opaque film base material, and is not limited to back-printing printing, but from the printing surface side. It may be a printing apparatus that manufactures a printed matter for observing a printed image.

<< Modification 7 >>
In the above-described embodiment, one side of the base material 12 is a printed surface and the other side is a non-printed surface, but the present invention can also be applied to a printing apparatus that performs double-sided printing. For example, in the case where an image is printed on the first surface of the base material and then the image is printed on the second surface on the opposite side, the second surface is understood as the "printing surface" when the second surface is printed. ..

<< Modification 8 >>
Although the non-permeable base material 12 has been described as an example in the above-described embodiment, the technique of the present disclosure can be applied to a low-permeability medium such as coated paper.

<< Modification 9 >>
In the above-described embodiment, the single-pass inkjet printing apparatus has been described, but the scope of application of the present invention is not limited to this, and a plurality of short print heads such as a serial type (shuttle scan type) head may be moved. The present invention can also be applied to a printing apparatus that records an image by scanning the head a number of times. In this case, the base material transport mechanism may adopt a configuration in which the base material is intermittently transported.

When a color image is formed using an inkjet print head, the heads may be arranged for each color of a plurality of colors of ink, or a configuration capable of ejecting a plurality of colors of ink from one print head may be used. Good.

<< About terms >>
The term "printing device" is synonymous with terms such as a printing machine, a printer, a printing device, an image recording device, an image forming device, an image output device, or a drawing device. "Image" shall be interpreted in a broad sense, and includes color images, black-and-white images, single-color images, gradation images, uniform density (solid) images, and the like. "Image" is not limited to a photographic image, but is used as a comprehensive term including a pattern, characters, symbols, line drawings, mosaic patterns, color-coded patterns, various other patterns, or an appropriate combination thereof.

The term "printing" includes the concepts of terms such as image recording, image formation, printing, drawing, and printing. The term "device" includes the concept of the term "system".

<< Other >>
The items described in the configurations and modifications described in the above-described embodiments can be used in combination as appropriate, and some items can be replaced.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

10 Printing device 12 Base material 20 Unwinding part 22 Unwinding roll 23 Core 30 Precoat part 32 Coating roller 33 Precoat layer 34 Precoat drying part 40 First non-contact transfer part 42 Turn bar 44 Transport plate 44A Curved surface part 44B Flat part 45 Side plate 46 Rear back plate 48 Air outlet 50 1st suction drum 60 Jetting part 62K Inkjet head 62C Inkjet head 62M Inkjet head 62Y Inkjet head 62W Inkjet head 70 2nd suction drum 80 2nd contactless transport part 90 Winding part 92 Winding roll 100 Substrate transfer mechanism 202 Communication unit 204 User interface 206 Storage unit 210 General control unit 220 Unwinding control unit 222 Transfer control unit 224 First contactless transfer control unit 225 Suction drum control unit 228 Second contactless transfer control unit 230 Precoat control Unit 234 Precoat drying control unit 260 Jetting control unit 290 Winding control unit 410 Partition plate 412A, 412B, 412C Room 414, 414A, 414B, 414C Air supply pipe 440 Temperature control device 442 Temperature sensor 444 Heater 446 Pelche element 448 Controller 449 Temperature measuring instruments S11 to S24 Steps of control method for floating transport air S110 to S121 Steps of printed matter manufacturing method

Claims (16)

1. The unwinding part that unwinds the web-like base material,
   A non-contact transport unit that floats and transports the base material by blowing gas onto the base material unwound from the unwinding portion,
   An inkjet printing unit that prints an image by ejecting ink onto the base material that has passed through the non-contact transport unit.
   A winding unit that winds up the base material printed by the inkjet printing unit, and a winding unit.
   A temperature control device that controls the temperature so that the temperature variation of the gas blown out from the non-contact transport unit is within ± 4 ° C.
   A printing device equipped with.
2. The printing apparatus according to claim 1, wherein the temperature of the gas blown out from the non-contact transport unit is equal to or lower than the temperature of the ink discharged from the inkjet printing unit.
3. Further provided with a precoat portion for applying the undercoat liquid to the base material,
   The printing apparatus according to claim 1 or 2, wherein the precoat portion is arranged at a position upstream of the position of the inkjet printing portion in the transport path of the base material.
4. The printing apparatus according to claim 3, wherein the precoat portion is arranged at a position upstream of the position of the non-contact transport portion in the transport path of the base material.
5. A precoat drying portion for drying the undercoat liquid applied to the base material is further provided.
   The printing apparatus according to claim 4, wherein the precoat drying section is arranged at a position between the precoat section and the non-contact transport section in the transport path of the base material.
6. The undercoat liquid according to any one of claims 3 to 5, wherein the undercoat liquid contains a component that agglomerates or insolubilizes the color material component of the ink or thickens the ink by reacting with the ink. Printing device.
7. The temperature control device is
   A temperature sensor that detects the temperature of the gas and
   A heater that heats the gas and
   A cooling device that cools the gas and
   A controller that controls the heater and the cooling device based on a signal from the temperature sensor.
   The printing apparatus according to any one of claims 1 to 6.
8. The non-contact transport unit is further provided with a gas supply pipe for supplying the gas.
   The printing device according to claim 7, wherein the heater and the cooling device are arranged in the gas supply pipe.
9. The printing apparatus according to any one of claims 1 to 8, wherein the gas is air.
10. The printing apparatus according to any one of claims 1 to 9, wherein the non-contact transport unit changes the direction of the transport path of the base material toward the printing surface side of the base material.
11. The printing apparatus according to any one of claims 1 to 9, wherein the base material is a non-permeable film base material.
12. The printing apparatus according to any one of claims 1 to 11, wherein the inkjet printing unit includes a plurality of inkjet heads for ejecting inks of a plurality of colors.
13. The printing apparatus according to claim 12, wherein the inkjet printing unit includes an inkjet head that ejects white ink.
14. Unwinding the web-like base material from the unwinding roll and
    By blowing gas onto the base material unwound from the unwinding roll, the base material is floated and non-contact transport is performed.
    Printing is performed by ejecting ink from an inkjet head onto the base material that has passed through the non-contact transport portion in the transport path of the base material.
    Winding the base material printed by the inkjet head on a take-up roll and
    The temperature is controlled so that the temperature variation of the gas applied to the base material during the non-contact transportation is within ± 4 ° C.
    Printing methods including.
15. Transporting the base material by the roll-to-roll method and
    By blowing gas onto the base material in a part of the transport path of the base material, the base material is floated to perform non-contact transportation.
    Printing is performed by ejecting ink from an inkjet head onto the base material that has passed through the non-contact transport portion of the base material in the transport path.
    The temperature is controlled so that the temperature variation of the gas applied to the base material during the non-contact transportation is within ± 4 ° C.
    Printed matter manufacturing method including.
16. The printed matter manufacturing method according to claim 15, wherein the base material is a transparent film base material used for flexible packaging.

Images