Sheet material heating device, liquid ejection device, printing device

Abstract

To suppress density irregularity.SOLUTION: The device includes: a first transport belt 511 that transports a sheet material P provided with liquid; ultraviolet irradiation means 521 that heats the sheet material 511 transported by the first transport belt 511; and one or more second transport belts 411 that are provided on the upstream side of the first transport belt 511 and transport the sheet material P provided with liquid toward the first transport belt 511. The device transports the sheet material P in such a condition that the surface temperature of the second transport belts 411 is lower than the surface temperature of the first transport belt 511.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a device for heating a sheet material, a device for discharging liquid, and a printing apparatus. [Background technology]

[0002] Among devices that perform printing, etc. by applying liquid to a printing target (liquid application target) such as a sheet material, some are equipped with a heating means that heats the sheet material to which the liquid has been applied, thereby promoting drying of the applied liquid.

[0003] 2. Description of the Related Art Conventionally, a method is known in which a sheet material to which a liquid has been applied is heated by a heating means while being conveyed by a conveyor belt (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-154500 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the sheet material being conveyed by the conveyor belt is heated by a heating means, the conveyor belt itself is also heated and the temperature rises. If the temperature of the conveyor belt does not drop by the time the conveyor belt rotates and receives the sheet material, the sheet material comes into contact with the high-temperature conveyor belt, which causes a problem of uneven density.

[0006] The present invention has been made in view of the above problems, and has an object to suppress the occurrence of density unevenness. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention Claim 1 The apparatus for heating a sheet material according to the present invention comprises: a first conveyor belt for conveying the sheet material to which the liquid has been applied; a heating means for heating the sheet material conveyed by the first conveyor belt; one or more second conveyor belts arranged upstream of the first conveyor belt and configured to convey the sheet material to which the liquid has been applied toward the first conveyor belt; The second conveyor belt is a cooling means. the law of nature, A heat shield is disposed between the second conveyor belt and the first conveyor belt. The composition was as follows.

[0008] According to the present invention, it is possible to suppress the occurrence of density unevenness. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic explanatory diagram of a printing apparatus as a liquid ejecting apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view illustrating a discharge unit of the printing apparatus. [Diagram 3] 1 is a side view illustrating an apparatus for heating a sheet material according to a first embodiment of the present invention. [Figure 4] FIG. [Diagram 5] 10A and 10B are explanatory diagrams for explaining temperature unevenness of a sheet material and movement of a pigment contained in a liquid applied to the sheet material; [Figure 6] FIG. 11 is a diagram illustrating the relationship between the passage of time and ink fluidity. [Figure 7] FIG. 11 is a side view illustrating an apparatus for heating a sheet material according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a side view illustrating an apparatus for heating a sheet material according to a third embodiment of the present invention. [Figure 9] 10 is an explanatory diagram illustrating an example of the relationship between the amount of moisture and the time elapsed after printing, for explaining the transition of the amount of moisture in the liquid applied to the sheet material; FIG. [Figure 10] FIG. 11 is a side view illustrating a main part of an apparatus for heating a sheet material according to a fourth embodiment of the present invention. [Figure 11] FIG. 13 is a side view illustrating an apparatus for heating a sheet material according to a fifth embodiment of the present invention. [Figure 12] FIG. 13 is a side view illustrating an apparatus for heating a sheet material according to a sixth embodiment of the present invention. [Figure 13] FIG. 13 is a side view illustrating an apparatus for heating a sheet material according to a seventh embodiment of the present invention. [Figure 14] FIG. 13 is a side view illustrating a main part of an apparatus for heating a sheet material according to an eighth embodiment of the present invention. [Figure 15] FIG. 13 is a side view illustrating a main part of an apparatus for heating a sheet material according to a ninth embodiment of the present invention. [Figure 16] FIG. [Figure 17] FIG. 23 is a side view illustrating a main part of an apparatus for heating a sheet material according to a tenth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. A printing apparatus as a liquid ejecting apparatus according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic explanatory diagram of the printing apparatus, and Figure 2 is a plan explanatory diagram of an ejection unit of the printing apparatus.

[0011] The printing apparatus 1 includes an input section 10 for inputting a sheet material P, a pre-treatment section 20 which is a coating section, a printing section 30, a drying section 50, a reversing mechanism section 60, and an output section 70.

[0012] The printing device 1 applies (coats) a pretreatment liquid as a coating liquid to the sheet material P transported (supplied) from the transport section 10 in the pretreatment section 20 as necessary, and then applies the required liquid to the sheet material P in the printing section 30 to perform the required printing.

[0013] Then, the printing device 1 dries the liquid adhering to the sheet material P in the drying section 50, and then discharges the sheet material P to the discharge section 70 via the inversion mechanism section 60, either as is or after printing on both sides of the sheet material P.

[0014] The loading section 10 includes an input tray 11 (lower input tray 11A, upper input tray 11B) that stores multiple sheet materials P, and a feeding device 12 (12A, 12B) that separates and sends out the sheet materials P one by one from the input tray 11, and supplies the sheet materials P to the pre-processing section 20.

[0015] The pre-treatment section 20 includes, for example, a coating section 21 which is a treatment liquid application section that applies a treatment liquid to the printing surface of the sheet material P.

[0016] The printing unit 30 includes a drum 31 which is a support member (rotating member) that supports the sheet material P on its circumferential surface and rotates, and a liquid ejection unit 32 which ejects liquid toward the sheet material P supported by the drum 31.

[0017] The printing section 30 includes a transfer cylinder 34 which receives the sheet material P sent from the pre-processing section 20 and transfers the sheet material P between the drum 31, and a transfer cylinder 35 which receives the sheet material P transported by the drum 31 and transfers it to a second transport section 41.

[0018] The sheet material P transported from the pre-processing section 20 to the printing section 30 has its leading edge gripped by a gripping means (sheet gripper) provided on the transfer cylinder 34, and is transported as the transfer cylinder 34 rotates. The sheet material P transported by the transfer cylinder 34 is delivered to the drum 31 at a position opposite to the drum 31.

[0019] A gripping means (sheet gripper) is also provided on the surface of the drum 31, and the leading end of the sheet material P is gripped by the gripping means (sheet gripper). A plurality of suction holes are formed in a dispersed manner on the surface of the drum 31, and the suction means generates a suction airflow that flows inward from the required suction holes of the drum 31.

[0020] Then, the sheet material P transferred from the transfer cylinder 34 to the drum 31 has its leading edge gripped by the sheet gripper, and is adsorbed and supported on the drum 31 by the suction airflow of the suction means, and is transported as the drum 31 rotates.

[0021] The liquid discharge section 32 includes discharge units 33 (33A to 33D) which are liquid discharge means serving as liquid application means. For example, the discharge unit 33A discharges cyan (C) liquid, the discharge unit 33B discharges magenta (M) liquid, the discharge unit 33C discharges yellow (Y) liquid, and the discharge unit 33D discharges black (K) liquid. In addition, discharge units that discharge special liquids such as white, gold (silver), etc. can also be used.

[0022] The ejection unit 33 has a head module 100 including a full-line head in which a plurality of liquid ejection heads (hereinafter simply referred to as "heads") 101, each having a plurality of nozzle rows in which a plurality of nozzles 111 are arranged, are arranged in a staggered pattern on a base member 103, as shown in FIG.

[0023] The discharge operation of each discharge unit 33 of the liquid discharge section 32 is controlled by a drive signal corresponding to the printing information. When the sheet material P supported on the drum 31 passes through an area facing the liquid discharge section 32, liquid of each color is discharged from the discharge unit 33, and an image corresponding to the printing information is printed.

[0024] The sheet material P to which the liquid has been applied in the liquid discharge section 32 is transferred from the drum 31 to the transfer cylinder 35, and the sheet material P received by the transfer cylinder 35 is transferred to the second conveyor section 41 and then transferred from the second conveyor section 41 to the drying section (heating section) 50. In other words, the drum 31 faces the discharge unit 33, which is a liquid application means, and is a conveyor means that conveys the sheet material P to which the liquid has been applied toward the second conveyor section 41 (second conveyor belt 411).

[0025] The drying section 50 is a drying device that includes a heating means 52, and heats and dries the sheet material P to which the liquid has been applied while transporting the sheet material P transferred from the second transport section 41 by the first transport section 51.

[0026] The reversing mechanism 60 includes a reversing section 61 that reverses the sheet material P using a switchback method when performing double-sided printing on the sheet material P that has passed through the drying section 50 and has had liquid applied to one side and been dried, and a double-sided conveying section 62 that sends the reversed sheet material P back upstream of the transfer drum 34 of the printing section 30.

[0027] The discharge section 70 includes a discharge tray 71 on which a plurality of sheet materials P are stacked. The sheet materials P conveyed from the reversing mechanism section 60 are successively stacked and held on the discharge tray 71.

[0028] In this embodiment, an example is described in which the sheet material is cut sheet material, but the present invention can also be applied to devices that use continuous bodies (webs) such as continuous paper or rolled paper, and devices that use sheet materials such as wallpaper.

[0029] Next, the device for heating a sheet material according to the first embodiment of the present invention will be described with reference to Figures 3 and 4. Figure 3 is a side view of the device for heating a sheet material, and Figure 4 is a front view of the same.

[0030] The sheet material heating device 500 has a first conveying mechanism 501 as a first conveying means, a heating means 502 also serving as a drying means, a second conveying mechanism 401 as a second conveying means, and a pre-heating means 301.

[0031] The first conveying mechanism 501 has a first conveying belt 511 which is an endless conveying member that supports and conveys the sheet material P. The first conveying belt 511 is stretched between a driving roller 512 and a driven roller 513 and moves in a circular motion.

[0032] The first conveyor belt 511 is a belt having a plurality of openings that is sucked by a suction chamber 514, which is a suction mechanism arranged inside. For example, a mesh belt or a plain weave belt having suction holes is used. The suction chamber 514 performs suction using a suction blower, a fan, or the like. The conveyor is not limited to a conveyor using a suction method, and may be a conveyor that conveys the sheet material P using, for example, an electrostatic adsorption method or a gripper gripping method.

[0033] The heating means 502 includes a plurality of ultraviolet ray irradiation means 521 arranged along the sheet material conveying direction inside a housing 503. The ultraviolet ray irradiation means 521 irradiates the sheet material P conveyed by the first conveying belt 511 of the first conveying mechanism 501 with ultraviolet rays to heat it.

[0034] As shown in FIG. 3, the housing 503 is arranged with a gap between it and the conveyor belt 511 in the direction along the conveying direction, and as shown in FIG. 4, in the direction perpendicular to the conveying direction, the housing 503 has a portion 503a that extends below the conveyor belt 511 in the height direction.

[0035] Here, an example of the ultraviolet ray irradiation means will be described with reference to Fig. 5. Fig. 5 is a perspective explanatory view of the example of the ultraviolet ray irradiation means.

[0036] The ultraviolet irradiation means 521 has granular UV-LED light emitting elements 523 arranged in a lattice pattern on an irradiation surface 522. Each UV-LED light emitting element 523 emits light with the same illuminance, resulting in a state in which light is emitted uniformly along the irradiation surface 522 as a whole. The ultraviolet light (UV light) used has a peak wavelength of 395 nm and a wavelength distribution with a full width at half maximum of approximately 15 nm, but is not limited to this.

[0037] By irradiating with ultraviolet light, selective heating is possible, with the effect of heating only the image areas (areas where liquid has been applied) and not excessively raising the temperature of blank areas (areas where liquid has not been applied).

[0038] The results of comparing UV-LED with IR heaters (IR lamps) were as follows:

[0039] The heating conditions (output settings of the IR lamp and UV-LED) were varied and the surface temperature of the sheet material after it passed through the drying section was measured. The temperatures of the image area and the blank area were confirmed. When the temperature of the image area rose to around 90°C, the water and solvent in the water-based ink began to evaporate and the ink began to dry.

[0040] When heating with an IR lamp, the temperature of the image area was set to 90°C, and at the same time the temperature of the blank area was 105°C. In contrast, when heating with a UV-LED, when the temperature of the image area was similarly set to 90°C, the temperature of the blank area was 45°C, approximately 60°C lower than with an IR lamp.

[0041] Due to this difference in temperature of the blank part, when heated with an IR lamp, the moisture content of the blank part dropped from 6.1% to 1.4%, whereas when heated with a UV-LED, the moisture content of the blank part dropped only from 6.1% to 2.9%. In other words, it was confirmed that by heating with ultraviolet light, the blank part can retain more moisture after drying.

[0042] Returning to FIG. 3, the second conveying mechanism 401 is disposed on the upstream side of the first conveying belt 511 .

[0043] The second conveying mechanism 401 has a second conveying belt 411 which is an endless conveying member that supports and conveys the sheet material P. The second conveying belt 411 is stretched between a driving roller 412 and a driven roller 413 and moves in a circular motion.

[0044] The second conveyor belt 411 is a belt having a plurality of openings that is sucked by a suction chamber 414, which is a suction mechanism arranged inside. For example, a mesh belt or a plain weave belt having suction holes is used. The suction chamber 414 performs suction using a suction blower, a fan, or the like. The conveyor is not limited to a conveyor using a suction method, and may be a conveyor that conveys the sheet material P using, for example, an electrostatic adsorption method or a gripper gripping method.

[0045] Between the second conveyor belt 411 and the first conveyor belt 511, a guide member 560 is disposed as a guide member for guiding the sheet material P from the second conveyor belt 411 to the first conveyor belt 511.

[0046] The pre-heating means 301 heats the sheet material P before the sheet material P to which the liquid has been applied is transferred from the delivery drum 35 to the second transport belt 411.

[0047] The pre-heating means 301 is a non-contact heating means for heating the sheet material P without contact, and is composed of hot air blowing means 311 that blows hot air toward the transfer drum 35. The hot air blowing means 311 is equipped with a heater and a temperature detection sensor, and the blowing air temperature can be set from room temperature to about 100°C. From the viewpoint of suppressing cockling, it is preferable to use the heater OFF or at a low temperature. The hot air temperature is set arbitrarily based on information such as the amount of attached liquid and the type of sheet material (paper type).

[0048] Next, the temperature unevenness of the sheet material and the movement of the pigment contained in the liquid applied to the sheet material will be described with reference to Figures 5 and 6. Figure 5 is an explanatory diagram for the same description, and Figure 6 is an explanatory diagram for the same description of the relationship between the passage of time and ink fluidity.

[0049] In the drying process of liquid ink, the ink goes through the following steps: ejection from the head, landing on the sheet material, penetration, and evaporation. During this process, the pigment in the ink is fixed to the sheet material P (the pigment stops moving) between landing and penetration and evaporation.

[0050] Immediately after the ink lands on the sheet material, the pigment in the ink is still in a state where it is easy to move. If the pigment moves, the human eye will perceive the color intensity as different. Therefore, in order to obtain the desired image quality, it is necessary to suppress the movement of the pigment after the ink lands on the sheet material.

[0051] Here, the higher the temperature of the ink, the higher its fluidity. Therefore, for example, as shown in Figure 5(b), if there is a temperature unevenness (temperature gradient) in the in-plane direction of the sheet material P, for example, where the temperature in the center is relatively higher than on both sides, a surface tension difference occurs due to Marangoni convection, etc., and the pigment G moves from the high temperature area to the low temperature area (from the dotted line position to the black circle position). This causes the pigment in the low temperature area to increase, and the high temperature area is perceived as light and the low temperature area as dark.

[0052] Furthermore, ink fluidity also depends on the passage of time (elapsed time), as shown in Figure 6. In other words, over time, evaporation progresses, the viscosity of the ink increases, and the fluidity decreases. At this time, if the fluidity is above a certain threshold, the pigment can move, and this is recognized as density unevenness in the actual image.

[0053] Therefore, if there is a temperature difference in the area where the sheet material comes into contact when the ink is highly fluid immediately after it is applied to the sheet material, the pigment will move from the area with higher temperature to the area with lower temperature, as shown in Figure 5(a).

[0054] In order to prevent this pigment migration phenomenon, it is necessary to (1) eliminate temperature unevenness in the areas where the sheet material comes into contact, and (2) quickly reduce the fluidity to below the fluidity threshold at which pigment migration may occur.

[0055] In this embodiment, a pretreatment liquid is applied to the sheet material P to prevent the pigment from moving, and furthermore, preheating is performed to promote evaporation and penetration before the ink comes into contact with the transport unit, thereby increasing the viscosity of the ink. Note that if the temperature of the preheating is increased too much, the sheet material will also become hot, so it is necessary to suppress the temperature increase as much as possible.

[0056] Next, the operation of this embodiment will be described.

[0057] In this embodiment, as described above, the pre-heating unit 301 dries the liquid applied to the sheet material P until the pigment contained in the liquid no longer moves, and then passes the sheet material P to the second transport belt 411.

[0058] Since no heat source is disposed around the second conveyor belt 411, the temperature of the second conveyor belt 411 becomes approximately the same as the internal temperature of the device 500, which is the environmental temperature in which the device 500 is placed or slightly higher than the environmental temperature.

[0059] Therefore, the sheet material P handed over to the second conveyor belt 411 is conveyed in a room temperature environment, and the reduced temperature suppresses the movement of the pigment and also suppresses the occurrence of cockling.

[0060] Thereafter, the sheet material P is transferred from the second conveyor belt 411 to the first conveyor belt 511, and the sheet material P conveyed by the first conveyor belt 511 is irradiated with ultraviolet light from the ultraviolet irradiation means 521, and the liquid (ink) is heated as described above, and dried to the final image quality.

[0061] In this manner, in this embodiment, the second conveyor belt 411 that conveys the sheet material P to which the liquid has been applied is disposed upstream of the first conveyor belt 511 that conveys the sheet material P to be heated by the heating means 502. Then, the sheet material P is conveyed in a state in which the belt surface temperature of the second conveyor belt 411 is lower than the belt surface temperature of the first conveyor belt 511.

[0062] As a result, the sheet material P to which the liquid has been applied is first transported by the second transport belt 411, which has a relatively low temperature, so that the fluidity of the liquid on the sheet material P decreases to a level at which the pigment does not move.

[0063] Then, the sheet material P is transferred to a first conveyor belt 511 for conveying the sheet material P to be heated by a heating means 502. Therefore, even if the temperature of the first conveyor belt 511 is high, the liquid on the sheet material P does not move, uneven density is suppressed, and quality is improved.

[0064] That is, the temperature of the first conveyor belt 511 that conveys the sheet material P increases due to heating by the heating means 502. Here, if the first conveyor belt 511 is configured to directly deliver the sheet material P from the delivery drum 35, the temperature does not decrease even when the first conveyor belt 511 returns to the position of the delivery drum 35 by rotating, and a high temperature state may be maintained.

[0065] At this time, as mentioned above, the sheet material P to which the liquid has been applied will come into contact with the hot first conveyor belt 511 while still in a state in which there is a possibility of the pigment moving, which may cause the pigment to move, resulting in uneven density and a decrease in quality.

[0066] Therefore, in this embodiment, by disposing the second conveyor belt 411 between the transfer drum 35 and the first conveyor belt 511, the fluidity of the liquid pigment applied to the sheet material P can be reduced to a level where it does not move, thereby reducing uneven density.

[0067] Next, a device for heating a sheet material according to a second embodiment of the present invention will be described with reference to Fig. 7. Fig. 7 is a side view of the device for heating a sheet material.

[0068] In this embodiment, the pre-heating means 301 is composed of a hot air blowing means 311 and an infrared ray irradiating means 312. The infrared ray irradiating means 312 irradiates the sheet material P transferred by the delivery drum 35 with infrared rays to heat it.

[0069] As a result, the sheet material P transferred from the delivery drum 35 to the second transport belt 411 can be dried earlier than in the first embodiment, and the movement of the pigment can be suppressed.

[0070] Next, a device for heating a sheet material according to a third embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a side view of the device for heating a sheet material.

[0071] In this embodiment, a heating element 551 for heating the driven roller 513 is disposed inside the driven roller 513, which is a rotating body around which the first conveyor belt 511 is wound. The heating element 551 is a heat generating means constituted by, for example, an infrared heater (IR lamp) and the like, and heats the inside of the driven roller 513, thereby heating the first conveyor belt 511 in contact with the driven roller 513.

[0072] The infrared heater as the heating element 551 is, for example, a carbon heater, a tungsten heater, a halogen heater, a ceramic heater, etc., but is not limited to these. In addition, by disposing the heating element 551 inside the driven roller 511, it is possible to transfer the heat of the heating element 551 to the surface of the driven roller 513 in the outer circumferential direction without any leakage, which is efficient.

[0073] In the apparatus 500 of this embodiment, the sheet material P transferred onto the first conveyor belt 511 from the upstream side is attracted to the first conveyor belt 511 by suction from the suction chamber 514 .

[0074] At this time, the driven roller 513 is heated by the heating element 551 in the driven roller 513, so that the first transport belt 511 from the driven roller 513 to the portion passing through the housing 503 is in a heated state.

[0075] As a result, the sheet material P that is attracted to and contacts the first conveyor belt 511 receives heat transferred from the first conveyor belt 511 side, and the temperature increases.

[0076] Then, as ultraviolet rays are irradiated toward the sheet material P by the multiple ultraviolet irradiation means 521 of the heating means 502, the ink as a liquid applied to the sheet material P absorbs the ultraviolet rays, the pigment in the ink generates heat, the ink solvent and moisture evaporate, and the ink dries.

[0077] In this manner, the pigment in the liquid (ink) generates heat while the temperature of the sheet material P is rising due to heat transfer from the first conveyor belt 511, so that the ink can be heated efficiently.

[0078] In this embodiment, a heat insulating material 570 is disposed between the second conveyor belt 411 and the first conveyor belt 511 as a heat shielding means to thermally separate the second conveyor belt 411 and the first conveyor belt 511. Furthermore, a cooling fan 415 is disposed to blow air to the second conveyor belt 411 so as to bring the temperature of the sheet material P closer to room temperature. This prevents the second conveyor belt 411 from being affected by the rise in temperature of the first conveyor belt 511.

[0079] Next, the transition of the moisture content of the liquid applied to the sheet material will be described with reference to Fig. 9. Fig. 9 is an explanatory diagram for explaining an example of the relationship between the elapsed time after printing and the moisture content, which will be used for the same description.

[0080] In Fig. 9, the vertical axis indicates the amount of moisture (ink application area: image area) on the sheet material P. "0" in the time elapsed after printing indicates the moment when ink is dropped from the head onto the sheet material P. Also, if the amount of moisture is above the pigment migration limit, the pigment is more likely to migrate, and if the amount of moisture is below that limit, the pigment does not migrate.

[0081] After the ink lands on the sheet material P, if the moisture content decreases from a high level to below the pigment mobility limit, the sheet material P will be able to come into contact with the first conveyor belt 511, which will then become hotter (the "OK" line shown by the solid line in the figure).

[0082] On the other hand, if the sheet material P comes into contact with the first conveyor belt 511 with the moisture content still equal to or greater than the pigment mobility limit, density unevenness occurs (the "NG" line shown by the dashed line in the figure).

[0083] In order to change a line that is NG to OK, the section of the second conveyor belt 411 can be lengthened or the moisture content can be reduced to the pigment movement limit by promoting moisture evaporation. Since lengthening the section of the second conveyor belt 411 increases the size of the device, it is better to shorten the second conveyor belt 411 by applying a heat quantity to the sheet material P that does not cause cockling.

[0084] Therefore, as described above, the pre-heating means 301 is provided to perform pre-heating to a degree that does not cause cockling.

[0085] Next, a device for heating a sheet material according to a fourth embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a side view illustrating a main part of the device for heating a sheet material.

[0086] In this embodiment, as guide members 560 serving as guiding means disposed between the second transport belt 411 and the first transport belt 511, a second guide member 562 on the upstream side and a first guide member 561 on the downstream side are disposed.

[0087] The second guide member 562 is disposed downstream of the second conveyor belt 411. The second guide member 562 is fixed by side plates on both sides intersecting the conveying direction. The second guide member 562 receives the sheet material P sent out from the second conveyor belt 411, and guides it to the first guide member 561.

[0088] The second guide member 562 has an inclined portion 562b as a first guide portion that inclines from the bottom to the top from the upstream end toward the downstream, and a second guide portion 561a downstream of the inclined portion 562b. The upstream end of the inclined portion 561b of the second guide member 562 is lower than the conveying path T shown by the imaginary line by a distance a. This makes it possible to scoop up the leading edge of the sheet material P even if the leading edge of the sheet material P moves along the outer periphery of the drive roller 412.

[0089] The first guide member 561 is disposed downstream of the second guide member 562 and upstream of the first conveyor belt 511, and guides the sheet material P to the first conveyor belt 511.

[0090] Here, as indicated by dashed line b, the downstream end of the second guide member 562 in the conveying direction is positioned directly above the upstream end of the inclined portion 561b of the first guide member 561 in the conveying direction, ensuring smooth transfer of the sheet material P.

[0091] The first guide member 561 receives the sheet material P transported on the second guide member 562, and guides it to the first transport belt 511. The first guide member 561 has an inclined portion 561b as a first guide portion that inclines from the bottom to the top from the upstream end toward the downstream, and a second guide portion 561a downstream of the inclined portion 561b.

[0092] As described above, the downstream end in the conveying direction of the second guide portion 562a of the second guide member 562 is disposed directly above (on the dashed line b) the upstream end in the conveying direction of the inclined portion 561a of the first guide member 561. Therefore, even if the leading end of the sheet material P that has passed through the second guide member 562 droops, it can be reliably received by the inclined portion 561b.

[0093] The orientation of the second guide portion 561a of the first guide member 561 is substantially the same as the orientation of the belt surface 511a of the first conveyor belt 511. This allows the orientation of the leading end of the sheet material P to follow the belt surface 511a, so that it is possible to prevent the sheet material P from flapping on the first conveyor belt 511 when the sheet material P lands on the belt surface 511a.

[0094] In this way, the area where the sheet material P does not come into partial contact with the belt surface 511a of the first transport belt 511 can be reduced, so that cockling of the sheet material P due to differences in dryness can be reduced.

[0095] The first guide member 561 is movable in a horizontal direction (a direction parallel to the belt surface 511a of the first conveyor belt 511).

[0096] A first conveyor belt 511 is disposed downstream of the first guide member 561 .

[0097] With this configuration, the sheet material P can be smoothly transferred from the second transport belt 411 to the first transport belt 511.

[0098] Next, a device for heating a sheet material according to a fifth embodiment of the present invention will be described with reference to Fig. 11. Fig. 11 is a side view of the device for heating a sheet material.

[0099] Heating means 502 of device 500 for heating a sheet material includes infrared ray irradiation means 531. Infrared ray irradiation means 531 includes near-infrared (NIR) heater 532. NIR heater 532 irradiates infrared rays having a peak wavelength in the near-infrared region (approximately 0.78 μm to 1.5 μm).

[0100] The moisture contained in the sheet material P has large absorption bands around 1.5 μm, 1.9 μm, and 2.5 μm, and the overall absorption gradually increases toward lower wavelengths. Therefore, if an NIR heater has a peak wavelength in the wavelength range below 1.5 μm, it can achieve the same effect as an ultraviolet ray irradiation means.

[0101] Furthermore, when the NIR heater 532 is used, the sheet material P can be heated from the conveying member side (conveyor belt 511 side), so that the output of the NIR heater 532 can be reduced or the number of NIR heaters 532 can be reduced.

[0102] Next, a device for heating a sheet material according to a sixth embodiment of the present invention will be described with reference to Fig. 12. Fig. 12 is a side view of the device for heating a sheet material.

[0103] Heating means 502 of device 500 for heating a sheet material includes hot air blowing means 541. Hot air blowing means 541 includes a fan 542 that draws in outside air, a flow path member 543, an outlet (nozzle portion) 544, and an infrared heater 545.

[0104] The hot air blowing means 541 heats air drawn into a flow path member 543 by a fan 542 with an infrared heater 545, and blows hot air 546 from a nozzle 544 toward the sheet material P. This increases the temperature of the solvent and moisture in the ink applied to the sheet material P while decreasing the vapor density in the vicinity of the sheet material P, thereby promoting evaporation.

[0105] In this embodiment, since the hot air 546 is also applied to the blank portions of the sheet material P, the moisture in the blank portions also evaporates. However, compared to the case where an IR heater is used to directly act on the absorption wavelength of water, excessive evaporation is suppressed, and waviness of the sheet material P can be suppressed.

[0106] In addition, when the hot air blowing means 541 is used, the sheet material P can be heated from the conveying member (conveyor belt 511) side by the heating element 551 or the like, and therefore the set temperature of the hot air blowing means 541 can be set lower to dry the sheet material P than when the sheet material P is not heated from the conveying member side.

[0107] Next, a device for heating a sheet material according to a seventh embodiment of the present invention will be described with reference to Fig. 13. Fig. 13 is a side view of the device for heating a sheet material.

[0108] In this embodiment, the pre-heating means 301 is composed of an ultraviolet ray irradiation means 312, and does not include the hot air blowing means 311 as in the first embodiment.

[0109] In this embodiment, the sheet material P is heated to such an extent that the flowability of the liquid applied to the sheet material P by the infrared ray irradiation means 312 is suppressed.

[0110] Furthermore, a mesh member 313 is disposed in front of the infrared ray irradiation means 312 between the transfer cylinder 35. This prevents contact between the infrared ray irradiation means 312, which is pre-drying the sheet material P, and the sheet material P when the sheet material P is transferred in the air from the transfer cylinder 35 to the second conveyor belt 411.

[0111] In place of the mesh member 313, a rotating or non-rotating guide means for guiding both ends of the sheet material P in the conveying direction may be provided to prevent contact between the infrared ray irradiating means 312 and the sheet material P.

[0112] Moreover, the pre-heating means 301 may be disposed inside the second conveyor belt 411 and upstream of the suction chamber 414 to pre-heat the sheet material P via the second conveyor belt 411 .

[0113] Next, an apparatus for heating a sheet material according to an eighth embodiment of the present invention will be described with reference to Fig. 14. Fig. 14 is a side view illustrating a main part of the apparatus for heating a sheet material.

[0114] In this embodiment, a heat insulating material 318 is disposed as a heat insulating means between the infrared ray irradiation means 312 and the second transport belt 411. A heat insulating material 318 is also disposed between the infrared ray irradiation means 312 and the drum 31.

[0115] This prevents the second transport belt 411 and the transport drum 31 from being heated by the infrared ray irradiation means 312, thereby suppressing uneven density.

[0116] The suction chamber 414 continues to perform suction at least during printing. Since the air sucked into the suction chamber 414 is at room temperature, the second transport belt 411 can be cooled between successively transported sheets P.

[0117] Next, a device for heating a sheet material according to a ninth embodiment of the present invention will be described with reference to Fig. 15 and Fig. 16. Fig. 15 is a side view of the main part of the device for heating a sheet material, and Fig. 16 is a perspective view of the main part.

[0118] In this embodiment, a housing (case) 417 that houses the second transport mechanism 401 has an opening 418 on the bottom surface thereof, which serves as an exhaust port.

[0119] As a result, the air sucked in by the suction chamber 414 of the second conveying mechanism 401 passes through openings (such as suction ports or mesh openings) in the second conveying belt 411, and is then exhausted into the printing device 1 through openings 418 in the housing 417.

[0120] Here, the suction chamber 414 of the second transport mechanism 401 is a cooling means for cooling the second transport belt 411, and is disposed on the transport path of the sheet material P between the liquid applying means (discharge unit 33) and the heating means 502.

[0121] In this way, a cooling means for cooling the second conveying belt is disposed between the liquid application means and the heating means in the sheet material conveying path, and the sheet material after liquid application is conveyed by the low-temperature second conveying belt before being heated by the heating means, thereby suppressing density unevenness.

[0122] The cooling means may include a suction fan (suction chamber 414), a blower (cooling fan), a control means for increasing the belt rotation speed, and other suppression means for suppressing an increase in temperature.

[0123] Next, a device for heating a sheet material according to a tenth embodiment of the present invention will be described with reference to Fig. 17. Fig. 17 is a side view illustrating a main part of the device for heating a sheet material.

[0124] In this embodiment, the suction chamber 414 sucks in the airflow a upstream of the position 419 where the sheet material P handed over from the transfer drum 35 to the second conveyor belt 411 lands on the second conveyor belt 411, thereby cooling the second conveyor belt 411.

[0125] This prevents the sheet material P preheated by the preheating means 410 from becoming too hot immediately after landing on the second conveyor belt 411.

[0126] The airflow sucked in by the suction chamber 414 is arranged inside the apparatus, and the exhaust of the airflow sucked in by the suction chamber 514 of the downstream high temperature side first conveying belt 511 is connected to an equipment duct of the building outside the apparatus and is exhausted outside the building.

[0127] Any of the devices for heating a sheet material according to the above-described embodiments can be applied to the printing device as the device for ejecting liquid described in the first embodiment.

[0128] In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but it is preferable that the viscosity of the liquid is 30 mPa·s or less at room temperature and pressure, or by heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, etc., containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural colorant, etc., and these can be used for applications such as inkjet ink, surface treatment liquid, a liquid for forming a component of an electronic element or a light-emitting element, an electronic circuit resist pattern, a material liquid for three-dimensional modeling, etc.

[0129] The aqueous pigment ink is not limited to the above-mentioned form, and may contain an ultraviolet polymerization initiator and an ultraviolet polymerizable compound. In this case, it is preferable that the content of the ultraviolet polymerization initiator and the ultraviolet polymerizable compound is such that curing by polymerization reaction does not occur or hardly occurs even when light is irradiated by a heating means. More specifically, the content of the ultraviolet polymerization initiator in the ink composition can be less than 0.1 mass %, or the content of the ultraviolet polymerizable compound in the ink composition can be less than 5 mass %. This makes it possible to reduce costs and obtain printed matter with good safety. The ultraviolet-polymerizable compound may be a monomer or an oligomer, etc. For example, methacrylic acid, etc. may be used.

[0130] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0131] Furthermore, the term "device for ejecting liquid" includes not only devices capable of ejecting liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0132] This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0133] For example, an example of a "liquid ejecting device" is an image forming device that ejects ink to form an image on paper.

[0134] In addition, the term "liquid ejection device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves and devices that create three-dimensional images.

[0135] The above-mentioned "object to which liquid can adhere" means an object to which liquid can adhere at least temporarily, and to which the liquid adheres and sticks, or to which the liquid adheres and penetrates, etc. Specific examples include media such as paper, recording paper, film, cloth, and other recording media, electronic boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects to which liquid can adhere.

[0136] The material of the above-mentioned "object to which liquid can adhere" may be any material to which liquid can adhere even temporarily, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, and ceramics.

[0137] Furthermore, the "liquid ejection device" may be a device in which a liquid ejection head and an object to which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which a liquid ejection head moves, a line type device in which a liquid ejection head does not move, etc.

[0138] Other examples of "liquid ejecting devices" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that ejects a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0139] In the present application, the terms image formation, recording, printing, imprinting, printing, modeling, and the like are all synonymous. [Explanation of symbols]

[0140] 1 Printing device 10 Loading section 20 Pretreatment section 30 Printing Department 50 Drying section 60 Reversing mechanism 70 Unloading section 301 Pre-heating means 311 Hot air blowing means 401 Second conveying mechanism 411 Second conveyor belt 500 Sheet material heating device 501 First conveying mechanism 502 UV irradiation unit 511 First conveyor belt 513 Driven roller 514 Suction chamber 521 Ultraviolet irradiation means 551 Heating element 560 Guide member (Guide member) 570 Insulation materials (heat shielding means)

Claims

1. a first conveyor belt for conveying the sheet material to which the liquid has been applied; a heating means for heating the sheet material conveyed by the first conveyor belt; one or more second conveyor belts arranged upstream of the first conveyor belt and configured to convey the sheet material to which the liquid has been applied toward the first conveyor belt; The second conveyor belt is a cooling means, A heat shield is disposed between the second conveyor belt and the first conveyor belt.

1. An apparatus for heating a sheet material, comprising:

2. a first conveyor belt for conveying the sheet material to which the liquid has been applied; a heating means for heating the sheet material conveyed by the first conveyor belt; one or more second conveyor belts arranged upstream of the first conveyor belt and configured to convey the sheet material to which the liquid has been applied toward the first conveyor belt; a pre-heating means for heating the sheet material to which the liquid has been applied before the sheet material is transferred to the second conveyor belt, The pre-heating means includes an infrared ray irradiation means for heating the sheet material, A heat insulating means is provided between the second conveyor belt and the infrared ray irradiating means.

1. An apparatus for heating a sheet material, comprising:

3. The pre-heating means is a non-contact heating means.

3. An apparatus for heating sheet material as claimed in claim 2.

4. The non-contact heating means is a means for blowing hot air onto the sheet material.

4. Apparatus for heating sheet material as claimed in claim 3.

5. A heat shield is disposed between the second conveyor belt and the first conveyor belt.

5. An apparatus for heating sheet material according to claim 2, 3 or 4.

6. a guide member provided between the second conveyor belt and the first conveyor belt for guiding the sheet material from the second conveyor belt to the first conveyor belt; 6. An apparatus for heating sheet material according to any one of claims 1 to 5.

7. The first conveyor belt is wound around at least two rotating bodies, and includes a means for heating at least one of the two rotating bodies.

7. Apparatus for heating sheet material according to any one of claims 1 to 6.

8. A liquid applying means for applying a liquid to the sheet material; and a sheet material heating device according to any one of claims 1 to 7. A liquid ejection device comprising:

9. a conveying means for conveying the sheet material to which the liquid has been applied toward the second conveying belt, the conveying means being opposed to the liquid applying means; 9. The liquid dispensing device according to claim 8.

10. A liquid applying means for applying a liquid to the sheet material; and a sheet material heating device according to any one of claims 1 to 7. A printing device comprising:

11. a conveying means for conveying the sheet material to which the liquid has been applied toward the second conveying belt, the conveying means being opposed to the liquid applying means; 11. The printing device according to claim 10.

12. a cooling means for cooling the second conveyor belt, the second conveyor belt is disposed at a position between the liquid applying means and the heating means in a conveying path of the sheet material, The cooling means cools the second conveyor belt disposed at the position.

9. The liquid dispensing device according to claim 8.

13. the cooling means is a suction means that sucks the sheet material onto the second conveyor belt, The suction means sucks in the air flow at a position where the conveyed sheet material contacts the second conveyor belt.

13. A device for dispensing liquid according to claim 12.

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