JP2006021343A - Inkjet recorder using ultraviolet-hardenable type ink and method for processing waste ink of inkjet recorder using ultraviolet-hardenable type ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder which is inexpensive and is not complicated in the structure of a waste ink container, and a safe and easy method for processing the waste ink, in an inkjet recorder using an ultraviolet-hardenable type ink. <P>SOLUTION: The inkjet recorder comprising a head for recording by ejecting the ultraviolet ray-hardening type ink on a recording medium and a waste ink container collecting the waste ink, has a charging means for charging a hardening accelerator into the waste ink container, and a heating means for heating the waste ink container. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a waste ink treatment of an ink jet recording apparatus using an ultraviolet curable ink.

In recent years, research and development of an ink jet recording apparatus using an ultraviolet curable ink capable of applying an image to various recording media has been advanced.
As a method for treating ink discharged by purging or ink replacement in a conventional ink jet recording apparatus using water-based ink, a waste ink tank is provided in the ink jet recording apparatus, and the waste ink is temporarily stored in the tank. In general, after a certain amount or more of ink has accumulated, it is generally discarded outside the recording apparatus.
However, in an inkjet recording apparatus using ultraviolet curable ink, if a conventional waste ink treatment method is used, the ultraviolet curable ink has skin irritation and odor in the liquid state, so the waste liquid ink is discarded. When doing so, problems such as the need for protective equipment and odor countermeasures occur.

As a method for solving this problem, Patent Document 1 proposes a method of irradiating waste liquid ink with ultraviolet rays to cure the waste liquid ink to a solid state and then discarding it.
However, in order to cure the waste ink using the ultraviolet irradiation apparatus, it is necessary to attach the ultraviolet irradiation apparatus to the waste liquid ink tank portion of the inkjet recording apparatus, which complicates the inkjet recording apparatus. Further, in this method, it is difficult to cure a large amount of waste liquid ink at a time, and it is necessary to cure every small amount, which is troublesome and costly.

Japanese Patent Laid-Open No. 2003-211705

  An object of the present invention is to solve the above problems, and in an inkjet recording apparatus using ultraviolet curable ink, an inkjet recording apparatus that is inexpensive and does not complicate the structure of a waste liquid ink tank, and a safe and easy disposal of waste liquid ink. To provide a method.

  The present invention implements the following means in order to solve the above problems.

  That is, (1) the present invention is an inkjet recording apparatus having a head for recording by discharging ultraviolet curable ink onto a recording medium and a waste ink tank for storing waste ink, and a curing accelerator is supplied to the waste ink tank. The present invention relates to an ink jet recording apparatus using ultraviolet curable ink, characterized by having injection means for injecting and heating means for heating the waste ink tank.

  (2) It is preferable that a film is mounted in the waste liquid ink tank.

  (3) It is preferable that a liquid repellent is applied in the waste liquid ink tank.

  Further, (4) in a method of treating waste ink of an inkjet recording apparatus using ultraviolet curable ink, a step of injecting a curing accelerator into a waste ink tank in which the waste ink is stored and a step of heating the waste ink tank The present invention relates to a waste ink processing method.

  (5) The curing accelerator is preferably an organic peroxide.

  ADVANTAGE OF THE INVENTION According to this invention, in the inkjet recording device using an ultraviolet curable ink, the inkjet recording device which is cheap and the structure of a waste-liquid ink tank is not complicated, and the safe and easy processing method of waste ink can be provided.

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

  The ink jet recording apparatus exemplified in the present embodiment performs recording by ejecting ultraviolet curable ink onto a recording medium, and then irradiates the ultraviolet rays by ultraviolet irradiation means to cure and fix the ink.

FIG. 1 is a schematic view showing a configuration of an ink jet recording apparatus using an ultraviolet curable ink showing an example of the present invention.
1 is a recording head, 2 is a carriage, 3 is a carriage conveying rail, 4 is a recording medium conveying device, and 5 is a maintenance unit for the recording head. The maintenance unit 5 is a suction cap used when discharging ink. 6, a suction pump 7 and a waste ink processing unit 8 for processing the waste ink are provided.
The recording head 1 is supplied with ultraviolet curable ink from an ink tank through a supply tube. The recording head 1 is mounted on the carriage 2 and moves on the carriage transport rail 3 along the rail. The recording medium is transported by the transport device 4 in a direction orthogonal to the direction in which the recording head 1 moves.

FIG. 2 is a schematic diagram showing a configuration of the waste liquid ink processing unit 8.
9 is a waste ink introduction pipe, 10 is a waste ink tank, 12 is a waste ink detection means, 13 is a heating means for heating the waste ink 11, 15 is a curing accelerator injection pipe, and 16 is a suction pipe. It is. Further, a heat insulating material 14 is provided around the waste ink tank 10 in order to increase heating efficiency.

FIG. 3 is a flowchart showing the flow of processing of waste liquid ink.
First, at the time of purging or ink replacement during ink jet recording, the suction cap 6 is mounted so as to cover the nozzle surface of the recording head 1, the suction pump 7 is operated, and the suction cap 6, the introduction tube 9, And the inside of the waste liquid ink tank 10 is made into a negative pressure. Then, the ink is guided to the waste liquid ink tank 10 through the introduction pipe 9 and temporarily stored.
Then, when a certain amount or more of ink is accumulated in the waste liquid ink tank 10, it is detected by the waste liquid ink detection means 12 provided in the waste liquid ink tank 10.
When detected by the detection means 12, the detection means 12 is lifted up to the upper part of the waste ink tank 10 so as not to contact the liquid surface of the waste ink 11, or after being taken out of the waste ink tank 10, the injection tube 15. More curing accelerator is injected.
Then, the waste liquid ink 11 is heated by the heating means 13 and the ink is cured. When the ink is completely cured, the cured ink is taken out from the waste ink tank 10 and discarded.

The material of the introduction tube 9 is not particularly limited as long as it has resistance to the ultraviolet curable ink flowing inside the tube, and examples thereof include metals such as stainless steel and aluminum, and plastic resins.
In addition, when the viscosity of the ultraviolet curable ink to be used is high, in order to increase the fluidity of the ink in the introduction tub 9, the introduction tub 9 may be heated using a heating means.

  The material of the waste liquid ink tank 10 may be any material that is resistant to ultraviolet curable ink and is heat resistant. Examples thereof include metals such as stainless steel and aluminum, and plastic resins. Of these, metals having good heat conduction are preferable, and stainless steel is more preferable in terms of workability and cost.

  Further, the shape of the inner surface of the waste liquid ink tank 10 may be a flat shape, but for example, a shape in which irregularities are provided inside the tank such that plates are arranged vertically from the bottom surface of the waste liquid ink tank 10 is preferable. By providing irregularities inside the tank, the contact area between the waste liquid ink tank 10 and the waste liquid ink 11 in the tank increases, and the waste liquid ink 11 can be heated more efficiently.

  Furthermore, it is preferable to cover the inner surface of the waste liquid ink tank 10 with a heat resistant film in advance so that the cured waste liquid ink can be easily taken out from the waste liquid ink tank 10. As the material of this film, plastic resins such as polyethylene terephthalate, polyethylene naphthalate, and polyethylene sulfide are preferable. If these plastic resins are used as a film, they can be disposed as waste plastic together with the cured ink, and workability at the time of disposal is good.

  Further, as another method for easily taking out the waste liquid ink cured from the waste liquid ink tank 10, a method of applying a silicone-based or fluorine-based liquid repellent to the inner surface of the waste liquid ink tank 10, or a liquid repellent such as PTFE dispersion plating. Examples thereof include a method for forming a film. In that case, it is necessary to use a drug or material that is durable for the ultraviolet curable ink.

Moreover, about the heating means 13, the method etc. which heat with an electrical energy using a resistor etc. are mentioned, However It does not specifically limit. Regarding the shape of the resistor, any shape such as a linear shape or a planar shape can be used.
About the installation position of the heating means 13, you may install outside a tank or may install in a tank. Further, it may be only the bottom surface of the tank, may be the bottom surface and the side surface of the tank, may be installed on the entire surface of the tank, or may be set arbitrarily.
Further, as the heating temperature of the waste liquid ink tank 10, curing does not start if the temperature is too low, and conversely, if the temperature is too high, the cured product may be melted. It is good to carry out in the range of ℃.

  In order to reduce energy loss during heating, it is preferable to cover the waste ink tank 10 with a heat insulating material 14. Examples of the material of the heat insulating material 14 include urethane foam resin, polystyrene foam, and glass wool. However, when using glass wool, in order to prevent the glass wool from scattering into the box, it is preferable to cover the periphery with foamed urethane resin or polystyrene foam.

In the present invention, when the waste ink 11 is heated and cured, a curing accelerator is injected in order to cure it more efficiently. What is necessary is just to control injection | pouring of a hardening accelerator using a solenoid valve etc., for example.
About the injection | pouring time of a hardening accelerator, in order to harden the waste liquid ink 11 in the waste liquid ink tank 10 more efficiently, it is preferable before heating the waste liquid ink tank 10. When a curing accelerator is injected after heating, only the ink in contact with the inner wall of the tank is cured, and the ink in the central portion of the tank may be in an uncured state.
In addition, after the injection of the curing accelerator, a stirring operation may be performed in order to further improve the ink curing efficiency. Examples of the agitation means include a method using a stirring rod driven by a motor and a stirring blade, a method in which an air introduction pipe is installed in a waste ink tank, and the waste ink is stirred using air.

Preferred examples of the curing accelerator include diacyl peroxides, dialkyl peroxides, ketone peroxides, hydroperoxides, peroxyketals, alkyl peresters, and percarbonates, among others, 1 hour. More preferred are those having a half-life temperature of 70 to 200 ° C. and capable of being stored at room temperature. The one-hour half-life temperature is the temperature at which the oxide concentration decreases to half of the initial value in one hour. If the one-hour half-life temperature is 70 ° C or less, attention should be paid to the expiration date and deterioration during storage. Above 200 ° C., the ultraviolet curable ink itself is cured without injecting a curing accelerator.
As the injection amount (solid content weight) of the curing accelerator, 1 to 5% of the weight of the waste liquid ink 11 to be cured in the waste liquid ink tank 10 is preferable because it can be efficiently cured.

  As for the waste ink amount detection means 12, a plurality of electrodes are provided in the ink tank to detect the liquid level using the conductivity of the ink, and the position of the float floating on the liquid level is detected. Means, means for detecting using a light emitting element and a light receiving element, and the like are exemplified, and are not particularly limited.

  When using a UV curable ink having a strong odor, when a small amount of the waste liquid ink 11 is accumulated in the waste liquid ink tank 10, the waste liquid ink is cured by the above-described method. What is necessary is just to repeat the process of making a waste ink accumulate in a tank and making it harden | cure in the state in a tank.

1 is a schematic diagram illustrating a configuration of an ink jet recording apparatus using an ultraviolet curable ink illustrating an example of the present invention. It is the schematic which shows the structure of the waste-liquid ink processing unit of this invention. It is a flowchart which shows the flow of a process of the waste-liquid ink of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head 2 Carriage 3 Carriage conveyance rail 4 Recording medium conveyance apparatus 5 Recording head maintenance part 6 Suction cap 7 Suction pump 8 Waste liquid ink processing unit 9 Introducing pipe 10 Waste liquid ink tank 12 Detection means 13 Heating means 14 Heat insulation material 15 Injection Tube 16 Suction tube

Claims (5)

In an inkjet recording apparatus having a head for recording by discharging ultraviolet curable ink onto a recording medium, and a waste ink tank for collecting waste ink, an injection means for injecting a curing accelerator into the waste ink tank, and the waste ink An ink jet recording apparatus using an ultraviolet curable ink, comprising a heating means for heating a tank. 2. An ink jet recording apparatus using ultraviolet curable ink according to claim 1, wherein a film is mounted in the waste ink tank. 2. An ink jet recording apparatus using ultraviolet curable ink according to claim 1, wherein a liquid repellent is applied in the waste ink tank. A method for treating waste ink of an ink jet recording apparatus using ultraviolet curable ink, comprising a step of injecting a curing accelerator into a waste ink tank in which the waste ink is stored and a step of heating the waste ink tank A method for treating waste ink. 5. The method for treating waste ink according to claim 4, wherein the curing accelerator is an organic peroxide.

Images