Plasma electron beam processing inkjet printing device

Abstract

The purpose of the present invention is to obtain a device that can be cured reliably even when printing is performed using an ink that does not contain a photopolymerization initiator, that can perform printing without modifying the surface of a substrate to be printed, and that, after printing of various colors, can be cured reliably without causing the surface of the substrate to be printed to be modified. The surface of the dots of the ink is cured by atmospheric pressure plasma, and thus an image having excellent resistance to the cured coating film can be obtained. Specifically, as a solution, provided is an inkjet printing device for multicolor printing, provided with: a multicolor inkjet nozzle that moves in the vertical direction with respect to the moving direction of a substrate to be printed and moves in the parallel direction with respect to the surface of the substrate to be printed; and a plasma discharge port facing the multicolor ink surface printed on the substrate to be printed downstream of the multicolor inkjet nozzle, and having an electron beam irradiation unit facing the moving direction of the substrate to be printed on the downstream side of the inkjet nozzle and the plasma discharge port.

Description

technical field [0001] The present invention relates to inkjet printing devices. Background technique [0002] As described in Patent Document 1, it is known to irradiate the ink on the printed substrate immediately after inkjet printing with ultraviolet rays under low oxygen concentration to polymerize the surface layer of the ink, and then irradiate the electron beam (hereinafter It is also called "EB") to polymerize the deep part and cure the whole. [0003] In addition, as described in Patent Document 2, it is known that the ink on the substrate to be printed immediately after inkjet printing is subjected to corona discharge treatment in an atmosphere having an oxygen concentration of less than 20,000 ppm to make the surface of the ink After polymerization, electron beams are irradiated next to polymerize the deep part and harden the whole. [0004] According to these curing units, although it is not necessary to mix a photopolymerization initiator in the ink, an atmos...

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Problems solved by technology

[0005] According to the above-mentioned background art, although it is possible to reliably cure an energy-ray polymerizable ink that does not contain a photopolymerization initiator as a result, it is necessary to form a region with a particularly low oxygen concentration.

In particular, as in the invention described in Patent Document 1, as a result, irradiation with ultraviolet light may be required, so it is actually difficult to cure the surface layer of an energy ray-curable ink that does not contain a photopolymerization initiator.

[0006] In addition, in the case of corona discharge treatment, if the distance between the electrodes is not sufficiently narrowed to about a few millimeters, it is difficult to perform the treatment stably

At this time, depending on the thickness of the printing paper and the degree of up-and-down movement of the moving printing paper, the ink may come into contact with the electrodes before the surface of the printed ink is cured, thereby disturbing the printing.

In addition, depending on the intensity of the corona discharge treatment, there is a possibility that the surface of the substrate to be printed such as paper to which no ink is attached may be modified.

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