Liquid dispensing device

Abstract

The material to be printed is thoroughly heated and dried using dielectric heating means. [Solution] The liquid application device 100 is characterized by having a humidifying means 20 for applying water to the material to be printed M, a dielectric heating means 60 for heating the material to be printed M, and a liquid application means 70 for applying liquid to the material to be printed M arranged in order from the upstream side to the downstream side of the transport path through which the material to be printed M is transported.

Description

Technical Field

[0001] The present invention relates to a liquid application device.

Background Art

[0002] Conventionally, in an inkjet printer, while transporting a printed object (such as paper) to which a pretreatment liquid is attached, hot air is applied to the printed object or a heat roller is applied to heat and dry the pretreatment liquid before printing.

Disclosure of the Invention

Problems to be Solved by the Invention

[0003] However, there is a problem that the printed object cannot be sufficiently heated and dried by hot air or a heat roller. On the other hand, Patent Document 1 (Japanese Patent Application Laid-Open No. 2013-238841) discloses an image fixing device in which the heating efficiency of a microwave heating device for fixing toner is improved.

[0004] Therefore, an object of the present invention is to provide a liquid application device that sufficiently heats and dries a printed object by dielectric heating means.

Means for Solving the Problems

[0005] In order to achieve the above object, the liquid application device of the present invention is characterized in that a humidifying means for applying water to the printed object, a dielectric heating means for heating the printed object, and a liquid application means for applying a liquid to the printed object are arranged in order from the upstream side to the downstream side of the transport path through which the printed object is transported.

Effects of the Invention

[0006] According to the present invention, the printed object can be sufficiently heated and dried by the dielectric heating means.

Brief Description of the Drawings

[0007] [Figure 1]This is a side view of a liquid dispensing device according to an embodiment of the present invention. [Figure 2] This is a side view of a humidifying means used in a liquid dispensing device. [Figure 3] (a) A perspective view and (b) A side view of a dielectric heating means used in a liquid dispensing device. [Figure 4] This is a perspective view of a dielectric heating method using a microwave heating unit. [Modes for carrying out the invention]

[0008] Hereinafter, an embodiment of the liquid dispensing device 100 of the present invention will be described with reference to Figures 1-4. As shown in Figure 1, the liquid dispensing device 100 has an endless belt B for conveying the material to be printed M. This endless belt B is stretched horizontally between the drive roller 10 and the driven roller 11.

[0009] The drive roller 10 is rotated counterclockwise by a motor or the like, causing the endless belt B to circulate in the direction of the arrow (counterclockwise). The endless belt B provides transportability that is independent of the size (paper size) of the material to be printed M.

[0010] A humidifying means 20 for supplying water to the material to be printed M is provided at the upstream end of the conveying path by the endless belt B. A dielectric heating means 60 for heating the material to be printed M is provided downstream of the humidifying means 20. A liquid supply means 70 for supplying liquid to the material to be printed M is provided downstream of the dielectric heating means 60.

[0011] ●Humidification means As shown in Figure 2, the humidifying means 20 is connected to the water tank 30 via a pump 40. The water supplied from the water tank 30 by the pump 40 is purified by passing impurities through a water purifier 21 attached to the humidifying means 20, and then heated and atomized by a fine nozzle and uniformly sprayed onto the upper surface of the material to be printed M. This suppresses uneven heating of the material to be printed M in the dielectric heating means 60 and shortens the heating time by increasing the amount of water molecules contained in the material to be printed M (improving heating efficiency).

[0012] ● Dielectric heating means The dielectric heating means 60 can be configured, for example, as a high-frequency dielectric heating means or a microwave heating means. The moisture in the printed material M is vibrated and heated by the high-frequency dielectric heating means or the microwave heating means.

[0013] The inner space of the dielectric heating means 60 is connected to the humidifying means 20 by a pipe 50. The dielectric heating means 60 is configured to recirculate water vapor generated from the material to be printed M back to the humidifying means 20 through the pipe 50.

[0014] The water vapor returned to the humidifier 20 is sent to a fine nozzle for reuse, where it is heated and atomized again and sprayed onto the upper surface of the printed material M. This reduces water usage and improves the thermal efficiency of the heating system.

[0015] Inside the dielectric heating means 60, the material to be printed M is not only sufficiently heated by the high-frequency dielectric heating means or the microwave heating means, but there is also ample space for the water vapor evaporated from the material to be printed to escape. Therefore, the material to be printed M can be heated and dried simultaneously before printing.

[0016] The high-frequency dielectric heating means utilizes short-wave or ultra-short-wave electromagnetic waves with a frequency band of 3 MHz to 300 MHz to form a high-frequency circuit. The object to be heated is placed in the high-frequency electric field formed between the electrodes on the circuit for dielectric heating. On the other hand, the microwave heating means utilizes extremely ultra-short-wave or centimeter-wave electromagnetic waves with a frequency band of 300 MHz to 30 GHz, emits electromagnetic waves from an oscillator to create a high-frequency electric field, and places the object to be heated there for dielectric heating.

[0017] The high-frequency dielectric heating means has, for example, a plurality of rod-shaped electrodes 61 as shown in FIGS. 3(a) and 3(b). The plurality of rod-shaped electrodes 61 are arranged in parallel at equal intervals below the printed object M conveyed along the conveyance path.

[0018] The direction of the rod-shaped electrode 61 is preferably perpendicular to the conveyance path. Thereby, the printed object M is heated uniformly in the width direction.

[0019] A high frequency is applied to the plurality of rod-shaped electrodes 61 by high-frequency application means. By applying a high frequency to the rod-shaped electrode 61, the printed object M can be heated by dielectric heating. Therefore, when the printed object M is conveyed in the direction of the arrow in FIG. 3 by the endless belt B, different regions of the printed object M are sequentially heated.

[0020] As shown in FIG. 3(b), the rod-shaped electrodes 61 are arranged such that adjacent rod-shaped electrodes 61 have opposite polarities. For example, a high frequency of 100 MHz or less, more specifically, 10 MHz to 80 MHz, is applied to the rod-shaped electrode 61 by high-frequency application means. Then, the electric lines of force shown by the dotted line in FIG. 3(b) act on the printed object M and a heating action occurs.

[0021] The intensity of this heating action depends on the material. Generally, when a dielectric is placed in a high frequency, assuming the dielectric loss δ (dielectric loss angle), voltage E, and current Ic, it is known that heat of Ic·tanδ·E is generated. This tanδ is called the dielectric tangent, and the larger this value, the stronger the heating, and the smaller this value, the more difficult it is to be heated.

[0022] The driving frequency of the high-frequency dielectric heating means is preferably 100 MHz or less. When the driving frequency is 100 MHz or less, a simple shield configuration for suppressing unnecessary radiation can be used.

[0023] That is, in a commercial printing machine, a gap for paper feeding is formed in the apparatus main body. Therefore, when the frequency increases (the wavelength becomes shorter), unnecessary radiation leaks from the gap. However, if it is 100 MHz or less, leakage of unnecessary radiation can be reduced. Also, if the driving frequency is 100 MHz or less, a simple electrode configuration can be used.

[0024] The microwave heating means as the dielectric heating means 60 has a waveguide 62, a magnetron 63 for generating microwaves, and a reflector 64, as shown in FIG. 4. The waveguide 62 is installed in a state of bending a plurality of times in a stepped manner from the magnetron 63 to the reflector 64. The microwave heating means has no electrodes and generates microwaves with a frequency of 2450 MHz from the magnetron 63.

[0025] The generated microwaves are guided into the applicator by the waveguide 62 to create a standing wave, and the printed material M passes through it. This is the same configuration as a microwave oven.

[0026] ● Liquid application means The liquid application means 70 in FIG. 1 can be composed of, for example, one or two or more inkjet heads. Ink is supplied to this inkjet head from an ink tank (not shown). Then, small ink droplets are ejected from the inkjet head of the liquid application means 70 onto the printed material M that has been conveyed to directly below the liquid application means 70, and an image is formed on the printed material M.

[0027] Although the present invention has been specifically described above based on embodiments, it goes without saying that the present invention is not limited to the above embodiments and can be modified in various ways within the scope of the technical idea described in the claims. For example, the liquid application means 70 can be composed of one or more liquid application heads instead of an inkjet head. The amount of liquid applied can be adjusted by changing the pressing force of the liquid application heads against the material to be printed M.

[0028] <Note> Preferred embodiments of the present invention are as follows: <1> A liquid application device characterized by having, in order from the upstream side to the downstream side of a transport path through which a material to be printed is transported, a humidifying means for applying water to the material to be printed, a dielectric heating means for heating the material to be printed, and a liquid application means for applying liquid to the material to be printed. <2> The dielectric heating means is connected to the humidifying means by a pipe, and the dielectric heating means is configured to recirculate water vapor generated from the printed material through the pipe to the humidifying means. <1> A liquid dispensing device. <3> The humidifying means is characterized by having a fine nozzle, which atomizes water supplied from an external water tank and sprays it onto the workpiece. <1> or <2> A liquid dispensing device. <4> The humidifying means is characterized by having a water purifier, and the water supplied from the water tank is atomized by the fine nozzle through the water purifier. <3> A liquid dispensing device. <5> A liquid dispensing device according to any one of claims 1 to 4, characterized in that the printed material is conveyed by an endless belt arranged along the conveying path. [Explanation of Symbols]

[0029] 10: Driven roller 11: Driven roller 20: Humidification means 21: Pure water device 30: Water tank 40: Pump 50: Pipe 60: Dielectric heating means 61: Rod-shaped electrode 62: Waveguide 63: Magnetron 64: Reflector 70: Liquid dispensing means 100: Liquid dispensing device B: Endless belt M: Printed material [Prior art documents] [Patent Documents]

[0030] [Patent Document 1] Japanese Patent Publication No. 2013-238841

Claims

1. A liquid application device characterized by having, in order from the upstream side to the downstream side of a transport path through which a material to be printed is transported, a humidifying means for applying water to the material to be printed, a dielectric heating means for heating the material to be printed, and a liquid application means for applying liquid to the material to be printed.

2. The liquid dispensing apparatus according to claim 1, characterized in that the inner space of the dielectric heating means and the humidifying means are connected by a pipe, and the water vapor generated from the workpiece to be printed in the dielectric heating means is recirculated to the humidifying means through the pipe.

3. The liquid application apparatus according to claim 1, characterized in that the humidifying means has a fine nozzle, and water supplied from an external water tank of the humidifying means is atomized by the fine nozzle and sprayed onto the workpiece to be printed.

4. The liquid dispensing apparatus according to claim 3, characterized in that the humidifying means includes a water purifier, and the water supplied from the water tank is atomized by the fine nozzle through the water purifier.

5. A liquid dispensing device according to any one of claims 1 to 4, characterized in that the printed material is conveyed by an endless belt arranged along the conveying path.

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