US-12617217-B2 - Inkjet recording apparatus including precoating liquid head unit ejecting precoating liquid to printing base material

Abstract

An inkjet recording apparatus includes an ink head unit, a precoating head unit, a conveying plate, and a heating part. The ink head unit ejects ink to a printing base material conveyed along a predetermined conveying direction. The precoating liquid head unit is disposed on an upstream side of the ink head unit in the conveying direction and ejects precoating liquid to the printing base material. The conveying plate is disposed below the ink head unit and the precoating liquid head unit and on which the printing base material is conveyed. The heating part heats the conveying plate. When a temperature of the conveying plate below the precoating liquid head unit is set to T1, and a temperature of the conveying plate below the ink head unit is set to T2, the heating part heats the conveying plate such that T1 is less than T2.

Inventors

• Nobuhiro Maezawa

Assignees

• KYOCERA DOCUMENT SOLUTIONS INC.

Dates

Publication Date

20260505

Application Date

20240513

Priority Date

20230518

Claims (5)

1. 1 . An inkjet recording apparatus comprising: an ink head unit which ejects ink to a printing base material conveyed along a predetermined conveying direction; a precoating liquid head unit which is disposed on an upstream side of the ink head unit in the conveying direction and ejects precoating liquid to the printing base material; a conveying plate which is disposed below the ink head unit and the precoating liquid head unit and on which the printing base material is conveyed; and a heating part which heats the conveying plate, wherein when a temperature of a surface of the conveying plate below the precoating liquid head unit is set to T1, and a temperature of a surface of the conveying plate below the ink head unit is set to T2, T1 is a temperature at which the precoating liquid ejected from the precoating liquid head unit is not completely dried, T2 is a temperature at which drying of the ink is promoted, and, the heating part heats the conveying plate such that T1 is lower than T2 (T1<T2).
2. 2 . The inkjet recording apparatus according to claim 1 , wherein the temperature T2 of the conveying plate is 60 degrees Celsius or less.
3. 3 . The inkjet recording apparatus according to claim 1 , wherein the printing base material is a plastic film.
4. 4 . The inkjet recording apparatus according to claim 1 , wherein the precoating liquid head unit and the ink head unit have a same configuration.
5. 5 . The inkjet recording apparatus according to claim 1 , wherein the conveying plate is one, and the heating part includes a precoating heating part disposed below the precoating liquid head unit and an ink heating part disposed below the ink head unit.

Description

INCORPORATION BY REFERENCE This application is based on and claims the benefit of priority from Japanese patent application No. 2023-082021 filed on May 18, 2023, which is incorporated by reference in its entirety. BACKGROUND The present disclosure relates to an image forming apparatus which forms an image on a printing base material by an inkjet method. In an inkjet type image forming apparatus, when ink is ejected on a printing base material having a smooth surface such as a plastic film, the ink may move from a position where it landed and blot or may be mixed with other colored ink. In order to prevent such blotting and color mixing, a precoating treatment is generally performed in which a precoating liquid for suppressing ink spreading is ejected onto the printing base material before image formation. However, when the precoating liquid is ejected onto the printing base material, the temperature of the printing base material decreases, the reactivity between the ink ejected next and the precoating liquid decreases, and the blotting and color mixing are easily to occur. Accordingly, the inkjet printing apparatus may be provided with a platen for supporting the back surface of the printing sheet and an infrared lamp for heating the printing sheet through the platen. By heating the sheet conveyed on the platen, moisture in the ink is quickly evaporated, and drying of the ink is accelerated. Alternatively, the image forming apparatus may be provided with a treatment liquid supply means for supplying a treatment liquid and a treatment liquid drying means for heating and drying the treatment liquid film formed on a base material. The solvent in the treatment liquid is removed by the treatment liquid drying means, and adhesion between the color material of the ink and the base material is improved. When the sheet is heated or the treatment liquid film is dried as described above, if the evaporation of moisture in the ink proceeds too much, a defect such as clogging of the nozzle of the print head may occur. As described above, while it is preferable to increase the temperature of the printing base material in order to promote the drying of the ink, it is preferable that the temperature of the print head itself adjacent to the printing base material be as low as possible. In the above methods, it is difficult to control the temperature so as to make both of them compatible. SUMMARY An inkjet recording apparatus according to the present disclosure includes an ink head unit, a precoating head unit, a conveying plate, and a heating part. The ink head unit ejects ink to a printing base material conveyed along a predetermined conveying direction. The precoating liquid head unit is disposed on an upstream side of the ink head unit in the conveying direction and ejects precoating liquid to the printing base material. The conveying plate is disposed below the ink head unit and the precoating liquid head unit and on which the printing base material is conveyed. The heating part heats the conveying plate. When a temperature of a surface of the conveying plate below the precoating liquid head unit is set to T1, and a temperature of a surface of the conveying plate below the ink head unit is set to T2, the heating part heats the conveying plate such that T1 is lower than T2 (T1<T2). The above and other objects, features, and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present disclosure is shown by way of illustrative example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view schematically showing an image forming apparatus according to one embodiment of the present disclosure. FIG. 2 is a plan view showing a print head, in the image forming apparatus according to the embodiment of the present disclosure. FIG. 3 is a table showing an evaluation result of clogging of the nozzle and blotting. DETAILED DESCRIPTION Hereinafter, an image forming apparatus according to one embodiment of the present disclosure will be described with reference to the drawings. With reference to FIG. 1, the entire structure of the image forming apparatus 1 will be described. FIG. 1 is a front view schematically showing an internal structure of the image forming apparatus 1. The image forming apparatus 1 includes a feed roller 3 around which a long printing base material M is wound, an image forming part 5 which forms an image on the printing base material M fed from the feed roller 3, in an inkjet method, a drying part 7 which dries the image formed by the image forming part 5, and a rewinding roller 9 which winds the printing base material M dried by the drying part 7. The printing base material M is wound and mounted on the feed roller 3. By rotating the feed roller 3, the printing base material M is fed out in a predetermined conveying direction. The image forming part 5 is disposed on the down