JPH02277638A - Printing method of curved surface - Google Patents

Abstract

PURPOSE:To accurately print a pattern in a short time by making useless the control of registration by a method wherein after adhering ink materials for a base coat and for the pattern onto a blanket at a pitch interval corresponding to one revolution content of a curved surface of matter to be printed, the blanket and the matter to be printed are rotated by synchronizing with each other. CONSTITUTION:After adhering ink material 15 for a base coat and ink material 16 for a pattern on a blanket 4 for printing at a pitch interval of one revolution content of a curved part of matter 8 to be printed, the ink material 15 for base coat is transferred to the curved part while the blanket 4 and the matter 8 to be printed are being rotated by synchronizing with each other under a state of bringing the blanket 4 in contact with the curved part of the matter to be printed. Thereafter, the ink material 16 for pattern is transferred thereto. Thus, without requiring complicated control which registers a transfer position of the ink material for pattern by detecting a printed position of the base coat, the base coat and the pattern are accurately registered with each other at a corresponded position on the curved surface part of the matter 8 to be printed and printing can be performed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a curved surface printing method for printing by transferring ink to the circumferential surface of a printing medium having a curved surface such as a cylindrical container or a truncated conical cup. It is something.

[Conventional technology]

Conventionally, when printing designs such as trademarks or packaging figures on the circumferential surface of cylindrical containers, etc., in order to display the designs clearly, a base coat was formed by applying white or other ink to the surface of the container. Thereafter, this container is attached to a mandrel and supplied to a printing section, and the ink material for the pattern attached to the printing bracket is transferred onto the base coat.

[Problem to be solved by the invention]

The above-mentioned base coat is formed to a size that corresponds to the pattern area in consideration of the printing effect of the pattern, so if the printing position of the base coat and the printing position of the pattern deviate in the circumferential direction of the container, the pattern will move away from the penis coat. The print will protrude and the appearance of the print will deteriorate significantly. For this purpose, a mark sensor is provided to detect the printing position of the base coat formed on the circumferential surface of the cylindrical container, and while the mark sensor is performing detection, the container is rotated, and the printing position of the base coat is determined by the pattern ink. This requires complicated control such as stopping the rotation of the container at a point corresponding to the material transfer position to accurately align the printing location, which poses the problem of increasing the time required for printing.

The present invention was made in order to solve the above problems, and it is possible to accurately print a pattern on a base coat without the need for complicated control such as rotating and aligning the printing material. The present invention provides a curved surface printing method that can shorten the time required for printing.

[Means to solve the problem]

The present invention provides a curved surface printing method in which a printing blanket is brought into contact with a curved surface of a printing material attached to a mandrel and an ink material applied to the blanket is transferred to the curved surface. After depositing the ink material for the printing material and the ink material for the pattern at a pitch interval corresponding to one circumference of the curved surface, the blanket and the printing material are attached with the blanket in contact with the curved surface of the printing material. While rotating in sync with the printed matter,
After the ink material for the base coat is transferred to the curved surface portion, the ink material for the pattern is transferred thereon.

It is desirable to use an ink material with a lower viscosity than the base coat ink material as the pattern ink material to be adhered to the printing blanket.

In addition, the base coat ink material transferred to the curved surface of the printing material is moved to the contact area with the printing blanket through a drying process using a drying device, and the pattern ink material is applied onto the base coat ink material. It may also be transferred.

[Effect]

With the above configuration, in the present invention, when the printing material rotates once in synchronization with the printing blanket, the ink material for the base coat is transferred to the curved surface of the printing material to form a base coat, and then the printing material is transferred to the curved surface of the printing material. When the base coat rotates one more time, the ink material for the pattern is transferred onto the base coat, and the pattern is printed.

In addition, by using an ink material with a lower viscosity than the ink material for the base coat as the ink material for the above-mentioned pattern, when the ink material for the pattern is transferred onto the base coat, the ink material for the pattern can be used for printing. The ink material for the base coat is separated from the blanket and transferred onto the base coat, and the ink material for the base coat once transferred to the curved surface portion is prevented from being transferred to the ink material for the pattern located on the blanket. Therefore, it is possible to prevent the base coat ink material from being mixed with the pattern ink material on the blanket.

Furthermore, if the base coat ink material transferred to the curved surface of the printing material is dried by a drying device, the viscosity of the base coat ink material increases as it dries and hardens. , transfer to the pattern ink material side is prevented.

〔Example〕

FIG. 1 shows a curved surface printing facility for carrying out the curved surface printing method according to the present invention. This curved surface printing apparatus includes a turret 1 that is intermittently driven by a rotating mechanism, a plurality of mandrels 2 that are attached at predetermined intervals around the surface of the turret 1, and a mandrel drive mechanism 3 that rotationally drives the mandrels 2. A blanket 4 for printing is provided on the surface, a blanket cylinder 5 rotationally driven by a drive mechanism not shown, and a pair of inking units 6.7 for applying ink material to the blanket 4. There is.

As shown in FIG. 2, the mandrel 2 includes a holding part 9 to which a printing material 8 made of a transparent plastic container in the form of a truncated cone is removably attached, and a holding part 9 provided at the proximal end of the holding part 9. The turret 1 has a disk-shaped driven portion 10 and is rotatably supported by the turret 1. Then, when the turret 1 is intermittently driven by the rotating mechanism 11 and the mandrel 2 moves to the ink transfer position facing the surface of the blanket cylinder 5, the driven part 10 of the mandrel 2
contacts the drive belt 12 of the mandrel drive mechanism 3, and the mandrel drive mechanism 3 rotates the mandrel 2 in the opposite direction at substantially the same speed as the rotation speed of the blanket cylinder 5.

The printing blanket 4 is formed to have a length that is more than twice the total circumference of the printing substrate 8, and contains an inking unit 6 containing ink material for a base coat and an ink material for a pattern. With the inking unit 7, the two ink materials are applied at pitches corresponding to one circumference of the curved surface portion of the circumferential surface of the printing medium 8. In other words, the distance between the starting edge of the base coat ink material 15 applied on the blanket 4 and the starting edge of the pattern ink material 16 is set to be the same length as the entire circumference of the printing substrate 8. . Further, the ink material accommodated in the inking unit 7 for the above-mentioned pattern is set to have a lower viscosity than the ink material accommodated in the inking unit 6 for base coat.

A case will be described in which the curved surface printing method of the present invention is implemented using the curved surface printing apparatus having the above configuration. First, the printing material 8 transported by a feeder (not shown) is fitted onto the holding portion 9 of the mandrel 2 at the mounting position, and the plate cylinder 13 of the inking unit 6.7 is attached.
14, the ink material is simultaneously deposited on the blanket 4, and as shown in FIG.
5 and a pattern ink material 16 are deposited on the blanket 4 at pitches corresponding to one circumference of the curved surface of the printing medium 8. Next, the turret 1 is rotated by the rotation mechanism 11 to convey the mandrel 2 to which the printing material 8 is attached to the ink transfer position facing the circumferential surface of the blanket cylinder 5, and the curved surface of the printing material 8 is conveyed. 4. Abut against the blanket 4.

Then, the mandrel 2 is rotationally driven in the direction of the arrow in FIG. 4 by the mandrel driver t43, and while the printing material 8 is rotated in synchronization with the blanket 4, the blanket 4 is brought into contact with the curved surface of the printing material 8. After a base coat ink material 15 is transferred to this curved surface portion, a pattern ink material 16 is transferred thereon. That is,
The inking unit 6 containing the ink material 15 for the base coat is disposed upstream in the direction of rotation of the blanket 4 from the inking unit 7 containing the pattern ink material 16, and the inking unit 6 contains the ink material 15 for the base coat. Both ink materials 15.
16 onto the blanket 4, the ink material 15 for the base coat is first transferred to the curved surface of the printing substrate 8, and then, when the printing substrate 8 rotates once, the ink material 15 for the base coat transferred to the curved surface ink material 1
The ink material 16 for the above-mentioned pattern is transferred onto the image forming apparatus 5.

In this way, the base coat ink material 15 and the pattern ink material 16 are applied to the printing blanket 4 on the printing substrate 8.
After adhering at a pitch interval corresponding to one circumference of the curved surface of the printing material, while the blanket 4 and the printing material 8 are rotated in synchronism with the blanket 4 in contact with the curved surface of the printing material, After the ink material 15 for the base coat is transferred to the curved surface part, the ink material 16 for the pattern is transferred thereon, so the printing position of the base coat is detected and the transfer position of the ink material for the pattern is determined. The base coat and the pattern can be accurately aligned and printed at corresponding positions on the curved surface of the printing medium 8 without requiring complicated control for alignment.

Therefore, the printing material 8 made of transparent plastic material etc.
The base coat and the pattern can be accurately printed continuously without causing problems such as the pattern of a predetermined color protruding from the base coat, such as white, which is printed to cover a predetermined position of the base coat. This allows the above picture to be clearly displayed.

In particular, in the above embodiment, the mandrel drive mechanism 3 moves the mandrel 2 to which the printing medium 8 is attached to the ink transfer position.
Since the base coat 8 is rotationally driven by the blanket 4 and the rotation speed of the printing medium 8 is synchronized with the rotation speed of the blanket 4, the base coat and the pattern can be printed in a more accurately aligned state. That is, the printing blanket 4 is rotationally driven by a drive mechanism not shown.
It is also conceivable that the printing material 8 and the mandrel 2 are rotated in accordance with the driving force of the printing material 8, but in this case, if the frictional resistance acting between the blanket 4 and the printing material 8 changes, Since the rotational speed of the mandrel 2 changes, the printing positions of the base coat and the pattern shift accordingly. On the other hand, when the mandrel 2 is forcibly rotated at a predetermined speed by the mandrel drive mechanism 3 as described above, changes in the rotational speed due to the fluctuations in the frictional resistance do not occur. Therefore, the printing positions of the base coat and the pattern can be accurately matched.

In addition, when the viscosity of the ink material 16 for the pattern is set lower than the viscosity of the ink material 15 for the base coat as described above, the ink material 15 for the base coat transferred to the curved surface of the printing substrate 8 is When transferring the pattern ink material 16, the pattern ink material 16 with low viscosity separates from the blanket 4 and transfers onto the base coat, and the base coat once transferred to the curved surface portion It is possible to prevent the ink material 15 from separating from the curved surface portion and transferring to the blanket 4 side. Therefore, it is possible to effectively prevent printing defects caused by mixing of the ink materials 15 and 16 on the base coat 4.

Note that transfer of the base coat ink material 15 to the blanket 4 side can also be prevented by setting the thickness of the pattern ink material 16 to be adhered onto the blanket 4 to be larger than the base coat ink material 15. I can do it.

Further, as shown in FIG. 5, a drying device 17 consisting of a heater etc. is installed on the side of the mandrel 2 at the ink transfer position, and the ink material 15 for the base coat transferred to the curved surface of the printing substrate 8 is It may be configured such that the ink material 16 for the pattern is transferred onto the ink material 15 for the base coat by rotating it to the contact portion with the printing blanket 4 through a drying process by the drying device 17. In this case, when passing through the drying process, the base coat ink material 15 hardens to some extent and its viscosity increases.
This can prevent the base coat ink material 15 from transferring to the pattern ink material 16 side on the blanket 4, and when printing a halftone pattern pattern, the pattern ink material 15 can be prevented from transferring to the pattern ink material 16 side on the blanket 4. It is possible to prevent the base coat ink material 15 from swelling in areas where the ink is not transferred.

That is, in the case where halftone dot printing is performed by transferring the pattern ink material 16 onto the curved surface portion of the printing material 8 without curing the base coat ink material 15 transferred to the curved surface portion of the substrate 8, as shown in FIG. As shown in FIG. 2, when the above-mentioned pattern is printed, the base coat ink material 15 is pressed by the ink material 16, and due to the reaction, the ink material 16 for the pattern is pressed.
There is a risk that the ink material 15 for the base coat located in the area A where is not transferred may swell up and be transferred onto the blanket 4. However, after the ink material 15 for the base coat is cured as described above, the halftone dots of the pattern When printing is performed, swelling of the ink material 15 can be effectively prevented.

〔Effect of the invention〕

As explained above, in the present invention, an ink material for a base coat and an ink material for a pattern are applied to a printing blanket at a pitch interval corresponding to one circumference of a curved surface of a printing substrate, and then the above-mentioned blanket is attached. While the blanket and the printing material are in contact with the curved surface of the printing material and are rotated in synchronization, the base coat ink material is transferred to the curved surface, and then the pattern ink material is applied on top of the base coat ink material. Because the image is transferred, it is possible to print on the curved surface with the base coat and pattern accurately aligned without the need for complicated positioning control, which has the advantage of shortening the time required for printing. .

In addition, by using an ink material with a lower viscosity than the ink material for the base coat as the ink material for the above-mentioned pattern, when the ink material for the pattern is transferred onto the base coat printed on the curved surface of the printed matter, the above-mentioned The base coat ink material once transferred onto the curved surface portion can be effectively prevented from being transferred to the pattern ink material side on the blanket.

Therefore, it is possible to prevent the occurrence of a situation in which the ink material for the base coat is mixed into the ink material for the pattern located on the blanket and transferred to the subsequent printing material.

In addition, when the base coat ink material transferred to the curved surface of the printing material is dried by a drying device and then moved to the transfer position of the pattern ink material to print the pattern, When passing through the above drying process, the base coat ink material hardens and its viscosity increases.
This has the advantage that it is possible to prevent the ink material for the base coat from transferring to the ink material for the pattern on the blanket, and also to prevent the ink material for the base coat from rising when printing a halftone pattern pattern. There is.

[Brief explanation of drawings]

FIG. 1 is a front view showing a specific example of a curved surface printing apparatus for carrying out the curved surface printing method of the present invention, FIG. 2 is a side view showing the structure of the mandrel, and FIG. 3 is a perspective view showing the structure of the blanket. Figure 4 is a front view showing the state of transfer of ink material;
The figure is a partial front view showing a modification of the above-mentioned curved surface printing device.
The figure is a front view showing the state of transfer of ink material during halftone dot printing. 2...Mandrel, 4...Blanket, 8...
Printing material, 15... Ink material for base coat, 16
... Ink material for patterns, 17... Drying device. qshi

Claims (1)

[Claims] 1. In a curved surface printing method in which a printing blanket is brought into contact with a curved surface of a printing material attached to a mandrel and an ink material applied to the blanket is transferred to the curved surface, After attaching the ink material for the base coat and the ink material for the pattern to the blanket at a pitch interval corresponding to one circumference of the curved surface portion, with the blanket in contact with the curved surface portion of the printing medium, Curved surface printing characterized in that while the blanket and the printing material are rotated in synchronization, an ink material for a base coat is transferred to the curved surface portion, and then an ink material for a pattern is transferred thereon. Method. 2. The curved surface printing method according to claim 1, wherein the ink material for the pattern to be adhered to the printing blanket has a lower viscosity than the ink material for the base coat. 3. The base coat ink material transferred to the curved surface of the printing material is moved to the contact area with the printing blanket through a drying process using a drying device, and the pattern ink material is applied on the base coat ink material. 2. The curved surface printing method according to claim 1, wherein the curved surface printing method is adapted to be transferred.