Aqueous resin ink drying device and method for controlling drying of aqueous resin ink

Abstract

To suppress media damage caused by heat, and to implement appropriate drying treatment to suppress image degradation caused by high-temperature treatment.SOLUTION: An aqueous resin ink drying device 100 includes: a placing stand 212 on which printed media 10 is placed in a flat position; a drying chamber 203, which constitutes a space around the media and can dry the entire media by hot air; at least one fan heater unit FH; and a control unit 350 capable of variably controlling drying conditions by changing at least one of a fan control value, a heater control value, and a drying time, wherein the control unit 350 can set the heater control value to be equal to or higher than a glass transition temperature of the resin, and can change the drying conditions without changing the media placing condition, and can sequentially perform multiple drying operations having different drying conditions.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a water-based resin ink drying device, a method for controlling the drying of water-based resin ink, and the like. [Background technology]

[0002] For example, inkjet printing using solvent inks has traditionally been widely used to produce indoor and outdoor decorations and panels. However, solvent inks contain large amounts of VOCs (Volatile Organic Compounds), which pose a problem of concern as they may be harmful to the human body. To address this issue, water-based thermosetting inks called water-based resin inks, in other words latex inks that contain resin, have been developed in recent years, and we are now seeing examples of their use in actual inkjet printers that handle roll media.

[0003] Although the water-based resin ink is a water-based ink, it has the advantage of being weather resistant and can be printed on a variety of media (recording media).

[0004] In addition, water-based resin ink is expected to be applicable to a variety of media that is printed and dried by being laid flat on the mounting surface of the mounting section (i.e., a variety of media that is printed with a flatbed type printing device and printed with a flatbed type drying device).

[0005] After water-based resin ink (latex ink) is applied to media using an inkjet printer, it must be thermally dried to evaporate the water and dissolve and harden the resin to fix the coating. Drying water-based resin ink requires a heating process at fairly high temperatures (specifically the glass transition temperature: generally 70°C or higher) to dissolve and harden the resin. A drying device is used to dry the media.

[0006] In the paragraph

[0069] of the following Patent Document 1, with regard to the transition temperature (glass transition temperature) of the resin, it is stated that "it is preferably 120°C or lower, and from the viewpoint of further improving the abrasion resistance of the printed matter, it is more preferably less than 90°C, and even more preferably 80°C or lower."

[0007] Furthermore, claim 1 of Patent Document 1 discloses an inkjet recording device which performs "a treatment liquid applying step of applying a treatment liquid containing a coagulant to a recording medium; an ink applying step of ejecting an aqueous ink composition containing a colorant from an inkjet head to apply the same to the recording medium; a first heating step of heating the recording medium to which the treatment liquid and the aqueous ink composition have been applied, to a first surface temperature by a first heating mechanism; a cooling step of cooling the recording medium by a cooling mechanism after the first heating step; and a second heating step of heating the recording medium to a second surface temperature higher than the first surface temperature by a second heating mechanism provided downstream of the first heating mechanism in the recording medium transport direction after the cooling step."

[0008] Furthermore, in

[0004] of this Patent Document 1, it is stated that "when a treatment liquid containing a flocculant is used, a white haze occurs in the printed image." And in

[0005] of Patent Document 1, it is stated that the occurrence of the white haze can be suppressed by providing a cooling process for cooling the recording medium after the first heating process (and before the second heating process). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent Publication No. 2021-070244 Summary of the Invention [Problem to be solved by the invention]

[0010] The process of drying the media after printing is also carried out after printing with UV ink, for example. However, as mentioned above, drying water-based resin ink requires a fairly high-temperature heating process to dissolve and harden the resin. Therefore, the drying process will require a considerable amount of electricity compared to drying UV inks, etc., and it is expected that the drying equipment will need to be made larger and more powerful. In this case, it is conceivable that current printing equipment may not be able to cope.

[0011] It is also conceivable that flatbed type printing devices will be used to print advertisements, signs, flags, banners, car markings, displays, etc. (these are generally called sign graphics) that are installed indoors or outdoors. In this case, the printed media will be dried in a flatbed type drying device.

[0012] In addition, media used in printing with water-based resin inks must be heat-resistant, capable of withstanding high temperatures of, for example, 70°C to 90°C. However, even if the media can withstand the heat, if the quality of the printed image is degraded by high-temperature processing, then practical drying cannot be achieved. A wide variety of media are used, and appropriate drying processes must be implemented to prevent damage caused by heat and image deterioration caused by high-temperature processing.

[0013] The above-mentioned Patent Document 1 does not disclose anything about such problems, nor does it mention any means for solving them. Furthermore, Patent Document 1 describes that a first heating step is carried out at a first surface temperature, then a cooling step is carried out, and then a second heating step is carried out in which the surface is heated to a second surface temperature higher than the first surface temperature. However, this is for the purpose of preventing the occurrence of a "white mist" caused by using a treatment liquid containing a flocculant, and the occurrence of the "white mist" caused by the flocculant is not related to the present invention.

[0014] In addition, the present invention uses a so-called flatbed type drying means in which the media printed with water-based resin ink is placed flat in a drying chamber and dried.In contrast, Patent Document 1 is a type in which printing and drying are performed while transporting a roll-shaped media that can be wound up, and the drying method is fundamentally different from that of the present invention.

[0015] Meanwhile, the present inventors have conducted various studies on printing an image on a medium using a water-based resin ink and then carrying out an appropriate drying process using a flatbed type drying device, and have come to the following findings.

[0016] (1) A drying process is required to dry out the water contained in the water-based resin ink, and a drying process is required to dissolve the resin. If each drying process is not optimized, images of the desired quality may not be obtained. In addition, unnecessary power consumption may occur, making it difficult to reduce power consumption. (2) If further printing is to be performed on the media after the drying process, the media must be returned to the printing device (or returned to a printable state). However, if the media remains at a high temperature, it is highly likely that the media will expand and deform. If the media is transported in this state, the expanded and deformed shape may become fixed or the deformation may be further aggravated. To prevent this, it is necessary to wait until the temperature of the media drops to a state where it can be transported, but in this case, a problem arises in that the start of the next print job is delayed by the time of waiting. Furthermore, if printing is attempted while the media is still in a hot state, good printing may not be possible due to deformation of the printing surface, etc. The present invention has been made based on the findings of the inventors.

[0017] One object of the present invention is to provide an aqueous resin ink drying device that can perform an appropriate drying process so as to suppress damage to media caused by heat and suppress image deterioration caused by high-temperature processing.

[0018] Other objects of the present invention will become apparent to those skilled in the art by referring to the following exemplary aspects and best modes, as well as the accompanying drawings. [Means for solving the problem]

[0019] In order to facilitate an understanding of the outline of the present invention, embodiments according to the present invention will be illustrated below.

[0020] In an aspect according to the present invention, an aqueous resin ink drying device includes a mounting table on which a media printed with an aqueous resin ink is placed flat, a drying chamber that forms a space around the media and is capable of drying the entire media with hot air, at least one fan heater unit including a fan that generates the hot air and a heater, a fan control unit that controls the operation of the fan, and a heater control unit that controls the operation of the heater, and a control unit that is capable of variably controlling the drying conditions by changing at least one of the fan control value of the fan control unit, the heater control value of the heater control unit, and the drying time, wherein the control unit is capable of setting a heater control value as the heater control value that is equal to or higher than the glass transition temperature of the resin contained in the aqueous resin ink, and is capable of sequentially performing multiple drying processes with different drying conditions on the media placed on the mounting table by changing the drying conditions without changing the media's placement state.

[0021] According to an aspect of the present invention, a drying device capable of appropriately drying water-based resin ink can be realized. This drying device is capable of performing high-temperature treatment at or above the glass transition temperature of the resin. In addition, the media can be placed flat on the platform of a single drying device, and a plurality of drying processes can be carried out sequentially on the media while changing the drying conditions, for example.

[0022] Since various drying steps can be carried out, for example, continuously, without removing the media from the drying device, efficient drying is possible.

[0023] Furthermore, since the drying process can be appropriately controlled, for example, appropriate drying processing can be achieved that suppresses damage to the media due to heat and image deterioration due to high-temperature processing.

[0024] It is also possible to provide an appropriate cooling period after the drying process is completed. In this case, the time it takes for the temperature of the media to drop to a state where it can be transported (cooling waiting time) can be sufficiently shortened. Furthermore, the media, which has become quite hot due to the high-temperature drying process, can be efficiently cooled, and deformation of the media and deterioration of image quality due to high temperatures can also be suppressed.

[0025] Those skilled in the art will easily understand that the exemplified embodiments according to the present invention can be further modified without departing from the spirit of the present invention. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram showing an example of the main configuration of an example of a flatbed type inkjet printer that uses a water-based resin ink. [Diagram 2] 2A, 2B, and 2C are diagrams showing examples of the configuration of a water-based resin ink drying device. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of a water-based resin ink drying device that is separate from the printing device and is offline connected to the printing device. [Figure 4] FIG. 4(A) is a diagram showing an example of the appearance of an aqueous resin ink drying device that is integrated with a printing device and is connected to the printing device offline, and FIG. 4(B) is a diagram showing an example of the cross-sectional structure of the aqueous resin ink drying device. [Diagram 5] FIG. 5 is a diagram showing an example of a method for controlling the drying of a water-based resin ink. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The best mode described below is used to easily understand the present invention. Therefore, those skilled in the art should be aware that the present invention is not unduly limited by the mode described below.

[0028] In this specification, the term "inkjet printer" can include all printers that use printing methods using conventional inkjet technology, for example, continuous methods such as binary deflection methods or continuous deflection methods, thermal methods, or various on-demand methods such as piezoelectric methods.

[0029] In addition, "printer (inkjet printer)" can include 2D printers that print two-dimensional images and 3D printers (three-dimensional modeling devices) that create three-dimensional objects.

[0030] Furthermore, the term "ink" can be interpreted in a broad sense. For example, it can also be expressed as "liquid." For example, the term "inkjet printer" can also be expressed as "liquid ejection device" or "printing device."

[0031] (First embodiment) In the following description, the term "media (recording medium)" is used, but a typical example of the media is a thick, flat media (rigid media). However, this is just one example and the media is not limited to this example. A wide variety of media can be handled by flatbed printing devices and drying devices. For example, paper may be fixed to a mounting table, and media having irregularities on at least a portion of its surface may also be used.

[0032] Please refer to Fig. 1. Fig. 1 is a diagram showing an example of the main configuration of an example of a flatbed type inkjet printer that uses a water-based resin ink. In FIG. 1, the x direction is the main scanning direction (left-right direction), the y direction is the sub-scanning direction (depth direction), and the z direction is the height direction. It should be noted that the configuration of the flatbed inkjet printer shown in Fig. 1 is merely an example, and is not limited to the example of Fig. 1. For example, as another configuration of the flatbed inkjet printer, one in which the table moves in the sub-scanning direction and the carriage moves in the main scanning direction can be envisioned.

[0033] FIG. 1 shows an example (gantry type) of a flatbed type inkjet printer 1 (hereinafter, sometimes simply referred to as an inkjet printer) that uses water-based resin ink.

[0034] The flatbed type inkjet printer 1 using water-based resin ink in Figure 1 has a support section 20, a flatbed mounting section (hereinafter simply referred to as the mounting section) 22 having a mounting surface 23 on which media (sometimes simply referred to as the media) 10 is placed, a guide rail 24 that is movable in the Y direction, and an inkjet printing unit (hereinafter simply referred to as the printing unit) 28 that is guided by the guide rail 24 and movable in the x direction, and has a print head 26.

[0035] The print head 26 is capable of ejecting, for example, a W (white) water-based resin ink that can be used as a base when printing on transparent or colored materials, a primer (labeled "PR" in Figure 5) that functions as an optimizer, and water-based cyan inks of C (cyan), M (magenta), Y (yellow), and K (black) as process color inks onto the surface of the media 10 (in other words, the printing surface of the media 10).

[0036] The optimizer is composed of, for example, a colorless and transparent positively charged polymer and an aqueous auxiliary solvent (for example, 80% or more water). For example, when the optimizer is applied to the surface of the medium 10, an electrostatic attraction occurs between the positively charged optimizer and the negatively charged pigment particles of the aqueous resin ink, and the pigment particles can be quickly fixed to the surface (printing surface) of the medium 10.

[0037] Furthermore, the printing unit 28 may be equipped with an auxiliary drying unit (not shown) of a simple configuration.

[0038] Next, let us refer to Fig. 2. Fig. 2(A), (B), and (C) are diagrams showing examples of the configuration of a water-based resin ink drying device. In Fig. 2(A), (B), and (C), the same reference numerals are used to designate common parts. In the following description, the "water-based resin ink drying device" may be simply referred to as the "drying device." In FIG. 2A, the water-based resin ink drying device 100 is an oven-type drying device that is separate from the printing device and is offline connected to the printing device. The oven-type drying device generates hot air inside a drying chamber (constant temperature bath), which is a closed space, and blows the hot air onto the media 10 from above (in the +Y direction) to dry the water-based resin ink. In the figure, the hot air is indicated by a lined arrow.

[0039] In FIG. 2(A), the water-based resin ink drying device 100 has a box-shaped housing 201, a mounting table 212 on which a media 10 printed with water-based resin ink is placed flat, a drying chamber 203 that forms a space around the media and is capable of drying the entire media with hot air, at least one fan heater unit FH that has a fan 230 that generates hot air and a heater 220, a fan control unit 330 that controls the operation of the fan 230, and a heater control unit 320 that controls the operation of the heater 220, and a control unit 350 that is capable of variably controlling the drying conditions by changing at least one of the fan control value of the fan control unit 330, the heater control value of the heater control unit 320, and the drying time, and a filter (mesh filter, etc.) 199 that suppresses the scattering (movement) of foreign matter such as dust.

[0040] Next, reference is made to Fig. 2(B). In Fig. 2(B), the size of the medium 10 is larger than that in Fig. 2(A). To accommodate this, multiple fans and multiple heaters are used in the fan heater unit FH.

[0041] 2(B), multiple fans 230a, 230b, and 230c are arranged along the X direction. Similarly, multiple heaters 220a to 220c are arranged along the X direction. This expands the area dried by the hot air, and therefore the entire media 10 can be dried.

[0042] Next, reference is made to Fig. 2(C), which shows an example of the configuration of a smaller, more energy-efficient drying device. 2(C), a drying mechanism 30 is provided. The drying mechanism 30 has a fan heater unit FH and a ventilation section 31.

[0043] The fan heater unit FH has the same structure as that shown in Fig. 2(A), but is smaller in size and consumes less power. However, for the sake of convenience, the control unit 350 is not shown in Fig. 2(C).

[0044] The ventilation section 31 has multiple blowers 35a-35c that blow hot air toward the medium 10. Hot air is generated by one small, energy-saving fan heater unit FH, and the hot air is ventilated through the ventilation section 31 (which can be considered a single hollow ventilation pipe), and the hot air is then ejected (blow) downward (in the -Z direction) from the blowers 35a-35c provided at different positions. This allows the entire medium 10 to be dried.

[0045] According to the drying apparatus of FIGS. 2(A) to (C), various drying steps can be carried out, for example, continuously, without removing the media from the drying apparatus, making efficient drying possible. Furthermore, since the drying process can be appropriately controlled, for example, appropriate drying processing can be achieved that suppresses damage to the media due to heat and image deterioration due to high-temperature processing.

[0046] It is also possible to provide an appropriate cooling period after the drying process is completed, for example, so that the time it takes for the temperature of the media to drop to a state where it can be transported (cooling waiting time) can be made sufficiently short. Furthermore, the high-temperature drying process can efficiently cool the medium, which has become extremely hot, and can also prevent deformation of the medium and deterioration of image quality due to high temperatures.

[0047] According to the drying device of FIGS. 2(A) to (C), a water-based resin ink drying device is realized that can perform an appropriate drying process to suppress damage to the media due to heat and suppress image deterioration due to high-temperature processing.

[0048] Second embodiment Next, reference is made to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of a water-based resin ink drying device that is separate from a printing device and is offline connected to the printing device. Note that some parts in FIG. 3 are common to those in FIG. 2, and the same reference numerals are used for these parts. The water-based resin ink drying device 100 in FIG. 3 is a box-shaped oven-type drying device that dries an object to be dried by using a heat flow.

[0049] For example, when printing with aqueous resin ink using the flatbed type inkjet printer 1 shown in Figure 1 is completed, the worker removes the media 10 from the inkjet printer 1 and places it inside the aqueous resin ink drying device 100 installed near the inkjet printer 1.

[0050] The water-based resin ink drying device 100 includes a thermostatic chamber 200 and a drying device main body 300 .

[0051] The thermostatic chamber 200 has a housing 202, an opening / closing door 204 with a handle 206, a partition wall 210 that separates the internal space 208 of the thermostatic chamber 200 into upper and lower spaces, a mounting table 212 on which the media 10 is placed, at least one fan heater unit FH including a heater 220 and a fan 230 with an air intake 232, and a thermometer 242 such as a thermocouple that measures the temperature near the surface (in other words, the printing surface) of the media 10.

[0052] In the fan heater unit FH, when the heater 220 is turned on and the fan 230 is rotated, air heated by the heater 220 is sucked in through the intake port 232 of the fan 230, and circulation of hot air (heat flow) begins.

[0053] The hot air (heat flow) circulates counterclockwise in the internal space 208 of the thermostatic chamber 200. As a result, in the space above where the media 10 is placed, a stable laminar flow 240 that flows parallel to the plane of the media 10 is formed. This laminar hot air (heat flow) causes processes such as evaporation of moisture in the media 10, dissolution of the resin components, and hardening.

[0054] Furthermore, when the media 10 is being dried by the thermostatic chamber 200, the dry intake valve 244 and the exhaust valve 250 are opened to forcibly ventilate the internal space 208 of the thermostatic chamber 200. That is, when the dry intake valve 244 is opened, dry air is sent into the internal space 208 of the thermostatic chamber 200 via the intake duct 246, and when the exhaust valve 250 is opened, a portion of the air inside the thermostatic chamber 200 is exhausted to the outside of the thermostatic chamber 200 via the exhaust duct 248.

[0055] When drying of the media 10 is completed, the drying intake valve 244 is closed, while the exhaust valve 250 is opened to exhaust the air. After that, the opening and closing door 204 is opened, and the media 10 is carried out of the thermostatic chamber 200 by an operator.

[0056] The drying device main body 300 also includes an input / output interface (I / F) 310, a control unit 350 that controls the drying process performed by the thermostatic chamber 200, and a motor unit 340 that controls the rotation of the fan 230.

[0057] The motor unit 340 includes a motor 342 and a coupling portion 344 that couples the motor 342 to the fan 230 .

[0058] In addition, the input / output interface (I / F) 310 is connected to an input / output device 400 such as a computer that can be used to set the contents of the drying process, and a display device 500 that can be used to monitor the status of the drying process being performed.

[0059] The control unit 350 includes a heater control unit 320 and a fan control unit 330 .

[0060] The heater control unit 320 has a programmable regulator 322 that can set control data COM1, i.e., is programmable, for freely controlling the temperature near the surface of the media 10 in the thermostatic chamber 200. Temperature data TMP measured by the thermometer 242 is input to this programmable regulator 322.

[0061] The heater power of the heater 220 (in other words, the temperature near the surface of the media 10) and the duration of the heater power can be adjusted as appropriate based on the control data COM1 set in this programmable controller 322. For example, negative feedback control is performed so that the temperature data TMP measured by the thermometer 242 becomes a target value based on the control data COM1, thereby maintaining the temperature near the surface of the media 10 at a predetermined temperature.

[0062] The fan control unit 330 also has a motor control device 334 that controls the motor 342, and a programmable ROM 332 that can set control data COM2 for freely controlling the rotation speed and other parameters of the motor, that is, can be programmed.

[0063] The motor control device 334 can appropriately control the fan power (e.g., the number of rotations per unit time of the fan), the duration of the fan power, etc. A measurement signal RT of the rotation speed of the motor 342 is input to the motor control device 334. The motor control device 334 performs negative feedback control so that the input measurement signal RT of the rotation speed becomes a target value based on the control data COM2. This maintains the rotation speed of the motor 342 at a predetermined rotation speed.

[0064] Furthermore, the programmable controller 322 and the motor control device 334 can operate synchronously. For this synchronous operation (hereinafter referred to as synchronous operation), the programmable controller 322 supplies a synchronization signal SYN1 to the motor control device 334, while the motor control device 334 supplies a synchronization signal SYN2 to the programmable controller 322. The synchronization signals SYN1 and SYN2 realize synchronous operation of the programmable controller 322 and the motor control device 334, in other words, synchronous control.

[0065] Furthermore, the programmable regulator 322 constantly supplies a temperature monitor signal VC indicating the current temperature of the thermostatic chamber (the surface of the medium 10, i.e., the temperature near the print surface) to the input / output interface (I / F) 310. The current temperature of the thermostatic chamber is displayed on the display device 500 as monitor information.

[0066] Furthermore, the motor control device 334 constantly supplies a fan monitor signal MC indicating the current rotation speed of the fan, etc. to the input / output interface (I / F) 310. The current rotation speed of the fan, etc. are constantly displayed on the display device 500 as monitor information.

[0067] The control unit 350 can variably control drying conditions including a fan control value of the fan control unit 330 (e.g., a fan power value determined by the rotation speed of the fan), a heater control value of the heater control unit 320 (e.g., a heater power value represented by a temperature value near the surface of the media 10), and drying time as variables. In other words, the above drying conditions can be switched as appropriate.

[0068] According to the example of Figure 3, the media 10 coated with the water-based resin ink is placed flat in the thermostatic chamber 200 so that the ink does not drip, and the water-based resin ink can be dried by a stable laminar heat flow (hot air).

[0069] In other words, by generating circulating hot air by the fan heater unit FH for the medium 10 placed on the placement table of the thermostatic chamber 200, the entire medium 10 can be dried uniformly.

[0070] During the drying, the control unit 350 can variably control the drying conditions including the fan control value, the heater control value, and the drying time as variables. For example, the control can be implemented such that the drying process is divided into a plurality of processes and the drying conditions are switched in each process.

[0071] This makes it possible to independently control the fan control value, heater control value, and drying time, and to optimize their combination, in order to achieve the desired drying characteristics while sufficiently suppressing thermal damage to the media 10, taking into full consideration the material, heat resistance, and other characteristics of the media 10. This makes it possible to achieve both suppression of thermal damage to the media 10 and good drying properties.

[0072] (Third embodiment) Next, reference is made to Fig. 4. Fig. 4(A) is a diagram showing an example of the external appearance of a water-based resin ink drying device that is integrated with a printing device and is connected to the printing device offline, and Fig. 4(B) is a diagram showing an example of the cross-sectional structure of the water-based resin ink drying device. The water-based resin drying device in Fig. 4(A) is integrated with an inkjet printer 6 that uses water-based resin ink, so from another perspective, it can also be called a "printing device with a drying device." When the cover 12 shown in Fig. 4(A) is closed, a simplified drying chamber 205 is formed inside. It should be noted that "informal" means that it is a substantially closed space, i.e., it is not a completely sealed space and is not strictly a thermostatic bath, but is configured such that the internal temperature is generally maintained at a predetermined temperature. In addition, in FIG. 4(B), the movement of the hot air is indicated by arrows.

[0073] In Figure 4(A), an inkjet printer 6 using aqueous resin ink has a rail 8, a print head 9 movable along the rail 8, a platen (mounting section) 14 having a mounting surface 15, media 10 placed on the mounting surface 15 of the platen 14, a drying mechanism 40, a ventilation section 41 that forms part of the drying mechanism 40, and a cover 12. In FIG. 4(A), the cover 12 is open and no informal drying chamber is configured.

[0074] In FIG. 4B, when the cover 12 of the inkjet printer 6 is closed, a simplified drying chamber 205 is formed, and a circulation flow path 207 that circulates the heat flow (hot air) 37 counterclockwise is also formed. For convenience of explanation, the (simple) drying device integrated with the printing device configured in Fig. 4(B) is given the reference numeral 209. In the following explanation, it may be referred to as the "drying device 209".

[0075] In Fig. 4(B), a drying mechanism 40 having a configuration similar to that of the drying mechanism 30 in Fig. 2(C) described above is employed. This drying mechanism 40 has a fan heater unit FH' and a ventilation section 41. As in the case of Fig. 2(C), for the sake of convenience of explanation, a control section is not shown.

[0076] The ventilation section 41 has multiple blowers 36a-36c that blow hot air toward the medium 10. Hot air is generated by one small, energy-saving fan heater unit FH', and the hot air is ventilated through the ventilation section 41 (which can be considered a single hollow ventilation pipe), and the hot air is then ejected (blow) downward (in the -Z direction) from the blowers 36a-36c provided at different positions. This allows the entire medium 10 to be dried.

[0077] During the period in which the drying process using hot air is being performed, the hot air circulates counterclockwise through the circulation flow path 207. As a result, heat flow (hot air) 37a, which is a descending circulating flow, flows to draw in air near the boundary (lower gap) between the outside and the inside on the +Y side of drying device 209. Therefore, part of the internal air pressure at the end on the +Y side becomes negative relative to the outside air, and thus intake air flow 39a flows from the outside into drying device 209.

[0078] Furthermore, on the surface of the medium 10 in the drying device 209, there are heat flows 37b and 37c that flow near the surface of the medium 10 from the +Y side to the -Y side.

[0079] Here, a part of the heat flow (hot air) 37c becomes the exhaust air flow 39b and is discharged to the outside, but the other part is blocked by the inner wall of the drying device 209 on the -Y side and turns upward, generating the heat flow (hot air) 37d. This generates a circulating flow (heat flow 37) that flows counterclockwise.

[0080] In addition, on the +Y side, the heat flow (hot air) 37a, which is a descending circulating flow, and on the -Y side, the heat flow (hot air) 37d, which is an ascending circulating flow, both occur continuously in time. These continuous heat flows (hot air) 37a, 37d act as air curtains, creating a substantially closed space, suppressing temperature fluctuations within the drying chamber 205. In other words, although there is a slight error (within an acceptable range) in the temperature within the drying chamber 205, it can be considered that the temperature is generally maintained at a predetermined (constant) temperature.

[0081] (Fourth embodiment) Please refer to Fig. 5. Fig. 5 is a diagram showing an example of a method for controlling the drying of a water-based resin ink.

[0082] In the following description, the term "dissolving and hardening of resin (or resin component)" is used. The water-based resin ink used in the present invention contains a water-soluble polymer (a molecule that has a large molecular weight and is soluble in water) called a latex resin (sometimes simply referred to as resin). This latex resin is not dissolved in water when it is first applied, but dissolves in water and hardens when heated. In this embodiment, a process for evaporating the water contained in the water-based resin ink and drying it is distinguished from a process for dissolving and hardening the resin (resin component), and heat damage (thermal damage: for example, deformation or discoloration due to heat) inflicted on the media is suppressed in each process. Details of this point will be described later.

[0083] Furthermore, if latex resin that has dissolved in water and is in a liquid (or rubber-like) state continues to be heated, it will eventually undergo glass transition and become glassy. The temperature at which the glass transition occurs is called the "glass transition temperature." In order to melt and harden the resin, it is necessary to heat the resin to a temperature equal to or higher than its glass transition temperature. However, since the glass transition temperature of the resin is quite high, for example, about 70° C., it is preferable to set appropriate drying conditions during heating so as not to cause deformation or discoloration of the media. This point will be described later.

[0084] The printing process when printing on the medium 10 with water-based resin ink is divided into a white ink printing process shown in A-1 of FIG. 5, a drying process shown in A-2, printing processes of the colors C (cyan), M (magenta), Y (yellow), and K (black) shown in A-3, and a drying process shown in A-4. However, only one of the white ink printing process and the C, M, Y, and K printing processes may be performed, or a printing process of another ink may be included. Note that, in the following, a case where the C, M, Y, and K printing processes are performed after the white ink printing process will be described, but the order of the processes is not limited to this.

[0085] In addition, in the drying process shown in A-2 and A-4 of FIG. 5, the control unit 350 previously shown in FIG. 2 and FIG. 3 divides the drying process into a first process whose main purpose is to dry the water content of the water-based resin ink, a second process whose main purpose is to dissolve and harden the resin component contained in the water-based resin ink, and a third process whose main purpose is to cool the media, and performs control to switch the drying conditions for each of the first to third processes.

[0086] In the following description, the water-based resin ink drying device 100 shown in FIG. 3 is used. However, the drying device 100 shown in Figures 2(A) to 2(C) may also be used. Also, the drying device shown in Figures 4(A) and 4(B) may also be used as necessary.

[0087] For example, a user of the water-based resin ink drying device 100 shown in FIG. 3 can provide the control unit 350 with the above-mentioned control data COM1 and COM2 in advance to control the water-based resin ink drying device 100 so as to achieve good drying characteristics for the water-based resin ink while suppressing thermal damage to the media 10.

[0088] The printing process will be described step by step below.

[0089] In step S1, a primer PR as an optimizer and a white ink (WH) for forming a base are applied (printed) onto the medium 10. By applying the primer PR, the fixation of the water-based resin ink is improved, and deterioration of the image quality of the printed image can be suppressed.

[0090] After step S1 is completed, as shown in A-5 of Figure 5, white ink WH, which is a water-based resin ink containing water-based pigment PIG, resin RSN, and water WAT, is applied (printed) on the layer of primer PR.

[0091] Next, in step S2, the medium 10 after the white ink has been applied is removed from the flatbed inkjet printer 1 by an operator, and the medium 10 is set in the thermostatic chamber 200 of the drying device 100. That is, the medium 10 is placed flat on the placement table 212 of the thermostatic chamber 200.

[0092] Next, the drying process is carried out. As described above, the drying process is divided into a moisture drying process (step S3) as a first process mainly for drying moisture, a resin dissolving process (step S4) as a second process mainly for dissolving and hardening the resin component, and a cooling process (step S5) as a third process mainly for cooling the media, and the drying conditions including the fan control value, heater control value, and drying time as variables are variably controlled in each process.

[0093] In this embodiment, the drying conditions can be expressed by three variables: a fan power value as a fan control value, a heater power value as a heater control value, and a drying time. In other words, the drying conditions in this embodiment include the fan control value, the heater control value, and the drying conditions as variables. In this embodiment, the drying conditions are controlled to be switched for each process. In the present embodiment, for example, the moisture drying process is clearly distinguished from the resin dissolving and hardening process, and therefore, in the moisture drying process, drying conditions specialized for drying by evaporation of moisture can be set.

[0094] This makes it possible to realize drying that is focused on efficient evaporation of moisture while minimizing thermal damage to the media, taking into full consideration the thermal characteristics of media made of a variety of materials.

[0095] On the other hand, in the resin dissolving and hardening process, by setting drying conditions that emphasize temperature control, which is important in dissolving and hardening the resin, it is possible to achieve drying that is focused on dissolving and hardening the resin while suppressing thermal damage to the media.

[0096] Furthermore, by providing a process for cooling the media after drying, the expanded media returns to its original shape, and the possibility of deformation or the like occurring when the media is removed is significantly reduced, making it possible to start the next printing job sooner.

[0097] The specific details will be explained below. The air volume of the fan 230 is proportional to the rotation speed of the fan (in other words, the rotation speed of the motor 342). That is, the power of the fan (fan power) is indicated by the air volume of the fan, and since the air volume of the fan is determined by the rotation speed of the fan, the power of the fan can be defined based on the rotation speed of the fan.

[0098] For example, in step S3 of A-2 in Fig. 5, the fan power in the moisture drying process is shown to be 80%. This means that when the maximum power of the fan (in other words, the maximum rotation speed of the fan) is taken as 100%, a fan power (rotation speed of the fan) equivalent to 80% of the maximum power is selected in step S3. In this case, "80%" corresponds to the "fan control value."

[0099] Furthermore, for example, when the temperature of the heater 220 itself (heater temperature) is increased while keeping the airflow of the fan constant, the temperature of the heat flow (hot air) increases, and the temperature near the surface of the media 10 increases. In other words, there is a one-to-one correspondence between the heater temperature and the temperature near the surface of the media 10. Therefore, the power of the heater (heater power) can be represented by the temperature near the surface of the media.

[0100] In step S3, the heater power in the moisture drying process is shown to be 60° C., which means that the heater temperature is selected so that the temperature near the surface of the media will be 60° C. In this case, "60° C." corresponds to the "heater control value."

[0101] In the moisture drying process of step S3, the fan power is set to 80%, the heater power to 60° C. (temperature near the surface of the media), and the drying time is set to T1 (time t1 to t2).

[0102] As described above, the moisture drying process (step S3) is clearly distinguished from the resin dissolving and hardening process (step S4). In step S3, the drying conditions can be set to efficiently evaporate moisture while sufficiently suppressing thermal damage to the media.

[0103] That is, in step S3, if the glass transition temperature of the resin is 70° C., the heater power is set to “60° C.” so as to be lower than the glass transition temperature, thereby reducing thermal damage to the media.

[0104] On the other hand, lowering the temperature reduces the saturated vapor pressure, which is unfavorable in terms of drying the moisture. However, here, by setting the fan power to a high level of "80%, " the amount of air blown is increased and the humidity (degree of saturation of water vapor) is reduced, promoting the evaporation of moisture and ensuring good moisture drying characteristics.

[0105] In addition, since the above-mentioned appropriate fan power and heater power control is performed, the drying time in the moisture drying step can be set to a relatively short time T1, and therefore the drying time is prevented from becoming long. The time T1 is, for example, "5 minutes."

[0106] In this step S3, as shown in A-6 of FIG. 5, the water content WAT of the water-based resin ink is reduced by evaporation, while the particles of the resin RSN are aggregated and the particle size increases.

[0107] In step S4, the resin is melted and hardened. In step S4, the resin is melted and then needs to be glass-transitioned to a glass-like state, so the heater power is set to "80°C", which exceeds the glass transition temperature of the resin (70°C).

[0108] Meanwhile, the fan power is set to "30%." If the fan power is too high, the airflow rate increases, increasing the amount of heat dissipated from the media, making it impossible to maintain the high temperature of 80°C near the surface of the media; on the other hand, if the airflow rate is too low, the thermal energy required to heat the media cannot be sufficiently transferred to the surface of the media 10. Taking these points into consideration, in step S4, the fan power is set to a low level of "30%."

[0109] As a result, the drying time in the resin dissolving and hardening process in step S4 can be set to a relatively short time T2 (time t2 to t3), and the drying time is prevented from becoming long. The time T2 is, for example, "5 minutes".

[0110] In this step S4, as shown in A-7 of FIG. 5, the resin RSN is dissolved and hardened to form a coating film that covers the surface of the media.

[0111] In step S5, a media cooling process is performed. In this step S5, heater power is not required, so the heater is turned "off". Meanwhile, the fan power is made greater than the fan power in step S4. In a preferred example, the fan power is set to maximum in step S5. In other words, in order to promote heat dissipation from the media, in a preferred example, the fan power is set to "100%". Also, the time T3 in step S5 is, for example, "3 minutes".

[0112] By cooling the media after drying, the expanded media returns to its original shape, and the possibility of deformation occurring when removing the media is significantly reduced. This makes it possible to start the next printing (CMYK printing) sooner.

[0113] In step S5, as shown in A-8 of FIG. 5, as the media cools, the moisture remaining in the resin coating evaporates, forming a highly durable coating that completely covers the surface of the media.

[0114] 5A-3, the medium 10 is again set in the flatbed inkjet printer 1. In step S6, a primer and each of the inks of C, M, Y, and K are applied onto the medium 10.

[0115] In step S7, the medium is set in the drying device. That is, the medium 10 is removed from the flatbed inkjet printer 1 by an operator, and is placed flat on the placement table 212 of the thermostatic bath 200 in the water-based resin ink drying device 100 again.

[0116] 5A-4, the media coated with the inks of the colors C, M, Y, and K undergoes the following drying steps: drying the moisture (step S8), dissolving and hardening the resin (step S9), and cooling the media (step S10). The content of each step (steps S8 to S10) is the same as steps S3 to S5 described above, so detailed description will be omitted.

[0117] In step S8, the fan power is set to "80%", the heater power is set to "60° C.", and the time T4 (time t5 to t6) is set to "5 minutes".

[0118] In step S9, the fan power is set to "30%", the heater power is set to "80° C.", and the time T5 (time t6 to t7) is set to "5 minutes".

[0119] In step S10, as a preferred example, the fan power is set to "100%" (however, this is not limiting. In a broader sense, the fan power is set to a value greater than the fan power value in step S9). In addition, the heater power is set to "off," and the time T6 (times t7 to t8) is set to "3 minutes."

[0120] As described above, according to one aspect of the present invention, the drying apparatus includes a mounting table 212 on which a medium 10 printed with an aqueous resin ink is placed flat, a drying chamber 203 that forms a space around the medium 10 and is capable of drying the entire medium with hot air, at least one fan heater unit FH that is equipped with a fan that generates hot air and a heater, a fan control unit 330 that controls the operation of the fan 230, and a heater control unit 320 that controls the operation of the heater 220, and a control unit 350 that is capable of variably controlling the drying conditions by changing at least one of the fan control value of the fan control unit 330, the heater control value of the heater control unit 320, and the drying time, and the control unit 350 is capable of setting a heater control value as the heater control value that is equal to or higher than the glass transition temperature of the resin contained in the aqueous resin ink, and is capable of sequentially performing multiple drying processes with different drying conditions on the medium 10 placed on the mounting table 212 by changing the drying conditions without changing the mounting state of the medium 10.

[0121] According to the first aspect, it is possible to realize a drying device that can appropriately dry the water-based resin ink. The drying device of this embodiment can perform high-temperature processing at temperatures equal to or higher than the glass transition temperature of the resin, making it possible to dry water-based resin ink. In addition, the media can be placed flat on the platform of a single drying device, and a plurality of drying processes can be carried out sequentially on the media while changing the drying conditions, for example. Since the media can be laid flat, printing can be performed on thick, hard media, for example. Furthermore, since various drying steps can be carried out, for example, continuously, without removing the media from the drying device, efficient drying is possible. Furthermore, since the drying process can be appropriately controlled, for example, appropriate drying processing can be achieved that suppresses damage to the media due to heat and image deterioration due to high-temperature processing. It is also possible to provide an appropriate cooling period after the drying process is completed. In this case, the time it takes for the temperature of the media to drop to a state where it can be transported (cooling waiting time) can be sufficiently shortened. Furthermore, the media, which has become quite hot due to the high-temperature drying process, can be efficiently cooled, and deformation of the media and deterioration of image quality due to high temperatures can also be suppressed.

[0122] In a second aspect dependent on the first aspect, the water-based resin ink drying device may be an oven-type drying device and may be separate from a printing device that prints the water-based resin ink onto a medium.

[0123] According to the second aspect, a variety of media can be dried by an oven-type drying device that is separate from the printing device. Because it is separate from the printing device, it can accommodate larger media and can also accommodate higher power (higher output) drying devices.

[0124] In a third aspect dependent on the first aspect, the drying chamber is a substantially sealed drying chamber configured by making the space surrounding the media a substantially closed space, and the water-based resin ink drying device may be integrated with a printing device that prints the water-based resin ink on the media.

[0125] According to the third aspect, the water-based resin ink drying device can be integrated with the printing device, i.e., an inkjet printer equipped with a drying device and compatible with water-based resin ink can be realized.

[0126] In a fourth aspect which is dependent on any one of the first to third aspects, the control unit may divide the media drying process into a first process which is primarily intended to dry the water content of the aqueous resin ink, a second process which is primarily intended to dissolve and harden the resin component contained in the aqueous resin ink, and a third process which is primarily intended to cool the media, and may sequentially perform each of the first to third processes by switching the drying conditions for each of the first to third processes without changing the placement state of the media placed on the placement table.

[0127] In the fourth aspect, the drying process is clearly divided into three steps, and the drying conditions are changed in each step. In the moisture drying process, drying conditions specialized for drying by evaporation of moisture can be set. Therefore, by fully considering the thermal characteristics of media made of various materials, it is possible to realize drying that focuses on efficient evaporation of moisture while suppressing thermal damage to the media. In the resin dissolving and hardening process, drying conditions are set with an emphasis on temperature control, which is important in the resin dissolving and hardening process, making it possible to achieve drying that is focused on dissolving and hardening the resin while minimizing thermal damage to the media. Furthermore, by providing a process for cooling the media after drying, the media that has become hot during high-temperature processing can be efficiently cooled, shortening the waiting time for cooling. This allows the next printing to begin sooner, etc. Also, the expanded media returns to its original shape, and the possibility of deformation occurring when the media is removed is significantly reduced.

[0128] In a fifth aspect dependent on the fourth aspect, the control unit may, in a first step, set the drying time to a first time, set the fan control value to a first fan control value, and set the heater control value to the first heater control value at which the temperature near the surface of the media is lower than the glass transition temperature of the resin component contained in the aqueous resin ink; in a second step, set the drying time to a second time, set the fan control value to a second fan control value smaller than the first fan control value, and set the heater control value to the second heater control value at which the temperature near the surface of the media is higher than the glass transition temperature of the resin contained in the aqueous resin ink; and in a third step, set the drying time to a third time, set the fan control value to a third fan control value larger than the second fan control value, and set the heater control value to the third heater control value at which the heater is turned off.

[0129] In the fifth aspect, in the moisture drying process, the temperature near the surface of the media is set below the glass transition temperature of the resin to reduce thermal damage to the media, while the fan power is set strong to increase the amount of air blown, lowering the humidity (degree of saturation of water vapor) and promoting evaporation of the moisture. The drying time can be shortened to the first time, which also reduces thermal damage to the media. In the resin melting and hardening process, the temperature is set to above the glass transition temperature of the resin in order to melt and harden the resin, but if the amount of air blown is too much, the surface temperature of the media will drop, and conversely, if the amount of air blown is too little, the thermal energy transferred to the surface of the media will decrease and the temperature cannot be maintained, so taking these factors into consideration, the fan power is set to a low level while ensuring an air volume sufficient to maintain the temperature. The drying time can be shortened to the second time, which also reduces thermal damage to the media. Furthermore, in the media cooling process, heater power is not required, so the heater is turned off. On the other hand, the fan power is set to a third fan control value greater than the second fan control value (in a preferred example, for example, the airflow rate is maximized), which promotes heat dissipation from the media and speeds up cooling of the media. The drying time can be shortened to the third time, which also reduces thermal damage to the media.

[0130] In a sixth aspect, a method for controlling the drying of an aqueous resin ink includes dividing a drying process into a first process whose main purpose is to dry the water content of the aqueous resin ink, a second process whose main purpose is to dissolve and harden the resin component contained in the aqueous resin ink, and a third process whose main purpose is to cool the media, by placing a media printed with the aqueous resin ink flat on a placement table in a drying chamber and performing a drying process of the aqueous resin ink using hot air, and switching the drying conditions for each of the first to third processes without changing the placement state of the media, and performing each of the first to third processes in sequence.

[0131] According to the sixth aspect of the method for controlling drying of an aqueous resin ink, the drying process is clearly divided into three steps, and the drying conditions are changed in each step. In the moisture drying process, drying conditions specialized for drying by evaporation of moisture can be set. Therefore, by taking into full consideration the thermal characteristics of media made of various materials, it is possible to realize drying that focuses on efficient evaporation of moisture while suppressing thermal damage to the media. In the resin dissolving and hardening process, drying conditions are set with an emphasis on temperature control, which is important in the resin dissolving and hardening process, making it possible to achieve drying that is focused on dissolving and hardening the resin while minimizing thermal damage to the media. Furthermore, by providing a process for cooling the media after drying, the media that has become hot during high-temperature processing can be efficiently cooled, shortening the waiting time for cooling. This allows the next printing to begin sooner, etc. Also, the expanded media returns to its original shape, and the possibility of deformation occurring when the media is removed is significantly reduced.

[0132] In a seventh aspect dependent on the sixth aspect, at least one fan heater unit including a fan for generating hot air and a heater is used, and in a first step, the drying time is set to a first time, the fan airflow is set to a first fan airflow value, and the heater temperature is set to a first temperature value at which the temperature near the surface of the media is lower than the glass transition temperature of the resin component contained in the aqueous resin ink; in a second step, the drying time is set to a second time, the fan airflow is set to a second fan airflow value smaller than the first fan airflow value, and the heater temperature is set to a second temperature value at which the temperature near the surface of the media is higher than the glass transition temperature of the resin contained in the aqueous resin ink; in a third step, the drying time is set to a third time, the fan airflow is set to a third fan airflow value larger than the second fan airflow value, and the heater may be turned off.

[0133] In the seventh aspect, in the moisture drying process, the temperature near the surface of the media is set below the glass transition temperature of the resin to reduce thermal damage to the media, while the fan power is set strong to increase the amount of air blown, lowering the humidity (degree of saturation of water vapor) and promoting evaporation of the moisture. The drying time can be shortened to the first time, which also reduces thermal damage to the media. In the resin melting and hardening process, the temperature is set to above the glass transition temperature of the resin in order to melt and harden the resin, but if the amount of air blown is too much, the surface temperature of the media will drop, and conversely, if the amount of air blown is too little, the thermal energy transferred to the surface of the media will decrease and the temperature cannot be maintained, so taking these factors into consideration, the fan power is set to a low level while ensuring an air volume sufficient to maintain the temperature. The drying time can be shortened to the second time, which also reduces thermal damage to the media. In addition, in the media cooling process, heater power is not required, so the heater is turned off. On the other hand, the fan power is set to a third fan air volume value greater than the second fan air volume value (in a preferred example, the maximum air volume value is set), which promotes heat dissipation from the media and speeds up cooling of the media. The drying time can be shortened to the third time, which also reduces thermal damage to the media.

[0134] As described above, according to this embodiment, it is possible to provide a drying apparatus capable of drying a variety of media under a variety of drying conditions using a single drying apparatus. For example, a single drying device can be used to perform multiple drying processes with different main purposes for media printed with water-based resin ink (latex ink).

[0135] In addition, the drying conditions can be switched for each drying process, allowing each drying process to be optimized. This makes it possible to achieve both suppression of heat damage to the media and good drying properties when thermally drying water-based resin ink printed on media of various materials.

[0136] The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art could easily modify the above-described exemplary embodiments to the extent that they fall within the scope of the claims. [Explanation of symbols]

[0137] 1, 6... Flatbed type inkjet printer (inkjet printer, printer, printing device) using water-based resin ink, 8... Rail, 9... Print head, 10... Media (rigid media), 12... Cover, 14... Platen, 15... Placement surface, 20... Support part, 22... Flatbed placement part (placement part), 23... Placement surface, 24... Guide rail, 26... Print head, 28... Inkjet printing unit (printing unit), 30, 40... drying mechanism, 31, 41... ventilation section, 100... water-based resin ink drying device (drying device), 200... thermostatic chamber (drying oven), 201, 202... housing (box-shaped housing), 203... box-shaped housing, 206... handle, 204... opening and closing door, 208... inner space of thermostatic chamber, 209... drying device integrated with printing device (informal drying device), 210... partition wall, 212... 220 (220a to 220c) heater, 230 (230a to 230c) fan (circulation fan), 232 air intake, 240 laminar flow, 242 thermometer (thermocouple or the like), 244 dry air intake valve, 246 air intake duct, 248, 250, 300 dryer body, 310 input / output interface (I / F), 320 heater control section, 322 programmable controller, 330 fan Control unit, 334...motor control device, 332...programmable ROM, 340...motor unit, 342...motor, 344...coupling unit, 350...control unit, 400...input / output device, 500...display unit, FH (FH1 to FH3)...fan heater unit, PR...primer (optimizer), PIG...water-based pigment, RSN...resin (latex resin, resin component), WAT...water (moisture).

Claims

1. a placement table on which a medium printed with a water-based resin ink is placed flat; a drying chamber that defines a space surrounding the media and is capable of drying the entire media by hot air; At least one fan heater unit including a fan for generating the hot air and a heater; a fan control unit that controls the operation of the fan, and a heater control unit that controls the operation of the heater, and a control unit that is capable of variably controlling drying conditions by changing at least one of a fan control value of the fan control unit, a heater control value of the heater control unit, and a drying time; The control unit is As the heater control value, a heater control value that is equal to or higher than a glass transition temperature of a resin contained in the water-based resin ink can be set, By changing the drying conditions for the medium placed on the placement table without changing the placement state of the medium, a plurality of drying processes with different drying conditions can be sequentially performed. Water-based resin ink drying device.

2. The water-based resin ink drying device is an oven-type drying device and is separate from a printing device that prints the water-based resin ink on the medium. The water-based resin ink drying device according to claim 1 .

3. the drying chamber is a substantially sealed drying chamber configured by making the space around the medium a substantially closed space, The water-based resin ink drying device is integrated with a printing device that prints the water-based resin ink on the medium. The water-based resin ink drying device according to claim 1 .

4. The control unit is The step of drying the media is A first step is mainly for drying the water-based resin ink; a second step mainly for dissolving and curing a resin component contained in the water-based resin ink; a third step, the third step being mainly for cooling the medium after the second step; Divided into the first to third steps are sequentially performed by switching the drying conditions for each of the first to third steps without changing the state of the medium placed on the placement table. The water-based resin ink drying device according to claim 1 .

5. The control unit is In the first step, setting a drying time to a first time, setting the fan control value to a first fan control value, and setting the heater control value to a first heater control value at which a temperature near the surface of the media is lower than a glass transition temperature of a resin component contained in the water-based resin ink; In the second step, setting a drying time to a second time, setting the fan control value to a second fan control value smaller than the first fan control value, and setting the heater control value to a second heater control value at which a temperature near the surface of the media is equal to or higher than a glass transition temperature of a resin contained in the water-based resin ink; In the third step, setting a drying time to a third time, setting the fan control value to a third fan control value greater than the second fan control value, and setting the heater control value to a third heater control value at which the heater is turned off; The water-based resin ink drying device according to claim 4.

6. In a case where a medium printed with an aqueous resin ink is placed flat on a placement table in a drying chamber and a process of drying the aqueous resin ink by hot air is carried out, the drying process is A first step is mainly for drying the water-based resin ink; a second step mainly for dissolving and curing a resin component contained in the water-based resin ink; a third step, the third step being mainly for cooling the medium after the second step; Divided into A method for controlling the drying of a water-based resin ink, comprising: switching drying conditions for each of the first to third steps without changing the placement state of the medium; and sequentially carrying out each of the first to third steps.

7. At least one fan heater unit including a fan for generating hot air and a heater is used, and in the first step, Set the drying time to a first time; Setting the air volume of the fan to a first fan air volume value; setting a temperature of the heater to a first temperature value at which a temperature in the vicinity of a surface of the medium is lower than a glass transition temperature of a resin component contained in the water-based resin ink; In the second step, Set the drying time to a second time; setting the air volume of the fan to a second fan air volume value that is smaller than the first fan air volume value; setting the temperature of the heater to a second temperature value at which the temperature near the surface of the medium is equal to or higher than the glass transition temperature of a resin contained in the water-based resin ink; In the third step, setting the drying time to a third time, setting the air volume of the fan to a third fan air volume value greater than the second fan air volume value, and turning off the heater; The method for controlling drying of a water-based resin ink according to claim 6.

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