JPH01320166A - Glazing printing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device capable of glossing a printed surface.

[Conventional technology]

Conventionally, polishing is performed by coating a printed surface with a thermoplastic resin for polishing, and smoothing the coated surface with a pressure roller. This polishing method includes an end press method, a cylinder press method, and a melt coating method.

In the end press method, as shown in FIG. 2, the sheet to be processed 10 is conveyed in one direction in the horizontal direction with the thermoplastic resin coating layer facing upward, and the thermoplastic resin is heated by a preheating section 12 within the range of a belt conveyor 11. Preheat the coating layer. Further, the mirror-finished stainless steel belt 16 is connected to the preheating section 12.
It is disposed in a more downstream path and is hung between the heating roller 13 and the rotating roller 14. A pressure roller 15 is disposed below the heating roller 13, and the sheet to be processed 10 is passed between the heating roller 13 and the pressure roller 15, and at this time, the thermoplastic resin coating layer of the sheet to be processed 10 is is heating roller 1
3, the thermoplastic resin is heated to a temperature above the softening point and below the melting point of the thermoplastic resin, and is pressed against the mirror-finished stainless steel belt 16 with a large pressure by the pressure roller 15, thereby smoothing the surface. A shower 16a is disposed between the heating roller 13 and the rotating roller 14, and sprays water toward the thermoplastic resin coating layer of the processed sheet 10 to cool the thermoplastic resin coating layer. The thermoplastic resin coating layer of the sheet to be processed 10 is stuck to the mirror-finished stainless steel belt 16 while moving between the heating roller 13 and the rotating roller 14, but is not blown with pressurized air 17 at the rotating roller 14. hand,
It is peeled off from the mirror stainless steel heald 16.

In the cylinder press method, as shown in FIG. 3, the sheet to be processed 10 is preheated in a preheating section 12 and then passed between a mirror heating roller 18 and a pressure roller 15. During this passage, the thermoplastic resin coating layer of the sheet to be processed 10 is heated by the specular heating roller 18 to a temperature above the softening point and below the melting point of the thermoplastic resin, and
The surface is smoothed by the pressure applied from the pressure roller 15 to the surface of the mirror-finished heating roller 18 .

In the melt coating method, as shown in FIG. 4, a sheet-like base material 10' whose surface has not yet been coated is unwound from a material roll 1S and sent to a pressing section by a mirror cooling roller 20 and a pressure roller 15. It will be done. On the other hand, a T-die 21 is placed above the contact area between the mirror cooling roller 20 and the pressure roller 15.
is arranged, the molten resin 22 is dropped from this T-die 21 toward the contact area between the mirror cooling roller 20 and the pressure roller 15, and the sheet-like base material is dropped at the contact area between the mirror cooling roller 20 and the pressure roller 15. A thermoplastic resin coating layer is formed on the surface of 10'. The thermoplastic resin coating layer is cooled by the specular cooling roller 20, and its surface is smoothed by the pressure applied from the pressure roller 15 to the surface of the specular cooling roller 20.

[Problem to be solved by the invention]

However, the end press method and cylinder method
Before the thermoplastic resin coating layer of the processed sheet 10 becomes below the softening point, when the processed sheet NO is peeled off from the mirror stainless steel belt 16 and the mirror heating roller 18, -
The surface of the thermoplastic resin coating layer, which has been smoothed once, is destroyed and returns to a rough surface again, making it impossible to increase the processing speed very much. The maximum processing speed is, for example, 40 m/min in the former method and 30 m/min in the latter method.

For this reason, in this method, the processing cannot be performed continuously on the web printing press, and a discontinuous separate process is required, which causes an increase in costs.

Further, although the melt coating method can achieve a speed of 100 m/min or more, the resin must be coated in a molten state, and the coating layer is thick, which poses a problem in terms of cost. It is also difficult to pattern coat.

By the way, UV (ultraviolet) curable resin has a coating surface that is smooth and glossy due to its self-flowing property.

This invention focuses on the characteristics of the above-mentioned UV curing resin, and aims to make it possible to polish the printed surface continuously at the same speed as the operation of the web printing press.

[Means to solve the problem]

In order to achieve the above object, in the present invention, a UV curing resin coating machine and an ultraviolet irradiator are sequentially arranged downstream of the web printing machine, and the sheet to be treated is coated with the web printing machine,
It was run continuously through a UV curing resin coating machine and an ultraviolet irradiator.

In this gloss printing apparatus, the roll printing machine and the UV curable resin coating machine are configured by a gravure printing machine, and a dryer is provided in the travel path of the sheet to be treated between the coating machine and the ultraviolet irradiator. I can do it.

The above-mentioned ultraviolet ray irradiator may be composed of a plurality of irradiators, and a pressure roll for mirror-finishing the sheet to be treated may be provided between the irradiators.

In addition, the above-mentioned coating machine includes a gravure printing machine,
The same web printing machines as the above-mentioned roll printing machines, such as flexographic printing machines and offset printing machines, can be used. If they are the same, the printing and polishing lines will be of the same model, which will be advantageous for continuous operation.

[Effect]

Since the coating machine of the polishing printing apparatus configured in this way is a normal resin coating, it can be operated continuously at the same speed as the winding printing machine.
The coated surface is hardened by UV irradiation and becomes glossy.

If a gravure printing machine is used as the coating machine,
In order to facilitate its doctoring action, the UV curable resin must be diluted to lower its viscosity. This dilution usually involves mixing an organic solvent, but since the organic solvent inhibits the curing action in ultraviolet curing, the organic solvent is evaporated off using a dryer before curing. When UV-curable resin is diluted, its fluidity increases, resulting in a smooth coating surface and improved gloss.

In addition, in the case where the UV irradiator is composed of multiple units, the UV curable resin is plastically deformed by the irradiation in the previous stage, and
The resin is cured to the extent that it has no adhesive properties, and in this state, the resin surface is smoothed with moderate heating using a mirror-finished pressure roll, and then the polymerization is completed and cured by subsequent irradiation.

[Example] As shown in FIG. 1, this example consists of a printing process A, a coating process B, a drying process C1, a hardening and smoothing process D, and a punching process E. It is sent out from the take-up roll and travels through each process A, B, C, D, and E in sequence.

In the printing process A, a required number of gravure printing machines are arranged in series, and the sheet to be processed 1 passes through each of these printing machines to perform the required printing.

The coating process B consists of the same gravure printing machine as the printing process A, and here, the printing surface of the sheet to be processed 1 is coated with a UV curable resin.

The UV curable resin is diluted with an organic solvent to lower its viscosity so that it can be easily removed by a doctor.

The drying step C consists of a conventionally known hot air zone, heater, etc., in which the organic solvent is evaporated and removed from the UV-curable resin coating layer of the sheet to be treated 1.

The curing and smoothing process consists of a primary ultraviolet irradiator 3, a pressure roll 4 for mirror finishing, and a secondary ultraviolet irradiator 5. It is polymerized to the extent that it can be adhered to the pressure roll 4 and cannot be removed.

This incompletely cured coating layer is smoothed by applying appropriate heat and pressure using a pressure roll 4, and then polymerization is completed using a secondary ultraviolet irradiator 5. Note that the pressure roll 4 is capable of temperature control and pressure control as in the conventional case.

The punching process E consists of a conventionally known punching machine, and for example, punches out a carton in an unfolded state of a packaging box.

In the above example, when high-speed printing of 100 m/min or more (the feeding speed of the sheet 1 to be processed is 100 m/min or more) was performed, the operation could be performed without any problems, and the printing coating surface had an incident angle of 60° and a reflection angle of 60°. 80 on a 60° gloss meter
The above results were obtained, and the result was a one with more stern than the conventional one (around 70).

Note that in the coating step B, if pattern printing (partial printing) is performed, the amount of resin can be reduced.

〔Effect of the invention〕

As is clear from the above description, in this invention, polishing is performed using a UV curing resin coating, and the polishing process is not a discontinuous separate process from the printing process as in the past, but is a continuous process. As a result, printing and polishing become a series of continuous operations, significantly improving work efficiency.

Moreover, more effective polishing can be achieved by applying ultraviolet rays in multiple stages and creating a mirror surface by applying pressure between them.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of a gloss printing apparatus according to the present invention, and FIGS. 2 to 4 are schematic diagrams of conventional examples. A...Printing process, B...Coating process, C...Drying process, D...
・・Hardening and smoothing process, E・・・・Punching process, 1
．． 10... Sheet to be processed, 3... First
Next UV irradiator, 4... Pressure roll for mirror finish, 5...
・Secondary ultraviolet irradiator. Figure 1 Ω Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A UV curable resin coating machine and an ultraviolet irradiator are arranged in sequence after the web printing machine, and the sheet to be treated is continuously passed through the web printing machine, UV curable resin coating machine, and ultraviolet irradiator. A gloss printing device characterized by: (2) The winding printing machine and the UV curable resin coating machine are constituted by a gravure printing machine, and a dryer is provided in the traveling path of the sheet to be treated between the coating machine and the ultraviolet irradiator. A reading printing device according to claim (1). (3) In the polishing printing apparatus according to claim (1) or (2), the ultraviolet irradiator is composed of a plurality of units, and a pressure roll for mirror finishing of the sheet to be processed is provided between the irradiators. A gloss printing device featuring: