JP6711371B2 - Printer - Google Patents

Description

The present invention includes an endless transfer belt having an image area on the surface of which an ink image is formed, and a transport unit that moves a plurality of rotatable mandrels carrying a cylindrical object to be processed along a transport path. The present invention relates to a printing apparatus having a transfer station for transferring an ink image formed on an image area of a transfer belt to an outer peripheral surface of a body of a processing object.

Conventionally, in curved surface printing on the body of a cylindrical object such as a seamless can made of metal such as aluminum or steel, plate printing using a printing plate and inkjet printing or electrophotographic printing without a plate, etc. A method using is known.
As plate-type printing, for example, a dry offset is provided in which a plate cylinder of each color inker is provided with a resin relief plate, each color ink from the resin relief plate is transferred to a blanket, and the image is formed by transferring from the blanket to a rotatable mandrel object. Examples include printing.

Japanese Patent Publication No. 2016-511175

For example, in a printing device known in Patent Document 1, a blanket wheel or a blanket belt, which is a transfer member having an image area for forming an ink image on the surface, a rotatable mandrel carrying a cylindrical object, and a plurality of Is equipped with a mandrel wheel which is a carrying unit for moving the mandrel of FIG.
In these known offset printings, the mandrel itself does not have a drive mechanism, and the mandrel is configured to come into contact with the cylindrical object and the transfer member with a predetermined pressing force and to be driven by frictional force to rotate the mandrel. The object to be processed is set to rotate about once while passing through the transfer station, and the cylindrical object and the transfer member are pressed against each other before and after the image area.

At this time, when printing is performed on the entire circumference of the cylindrical object to be processed, the ink transferred to the object to be processed is pressed again onto the transfer member, and there is a problem that the quality of printing is deteriorated.
When the transfer member is a transfer belt and a convex blanket is not used to form an image area directly on the surface of the transfer belt, the transfer belt and the object to be processed should be separated from each other at the same time as the transfer is completed in order to avoid re-pressing. It is necessary to make adjustments, which makes the mechanism complicated and makes control difficult, and if the adjustments are misaligned and released slowly, re-compression bonding may occur, and if they are released early, printing may be incomplete.

The present invention solves these problems and does not require a complicated mechanism or advanced control, and the ink transferred to the object to be processed is pressed again onto the transfer member or printing is incomplete. It is an object of the present invention to provide a printing apparatus that prevents the above, maintains the printing quality even when the processing speed is increased, and obtains high production efficiency.

The printing apparatus according to the present invention is an endless transfer belt having an image area on the surface of which an ink image is formed, a rotatable mandrel carrying a cylindrical object to be processed, and a plurality of the mandrels as a transport path. A printing apparatus having a transfer unit for moving the ink image formed in the image area of the transfer belt to the outer peripheral surface of the body of the object to be processed, wherein the transfer belt, The transfer belt is wound around a cylindrical wheel that rotates in a range including at least the transfer station, and the transfer belt has at least a portion wound around the wheel, in which the ink transferred to the outer peripheral surface of the body of the object to be processed is The above problem is solved by having a non-crimp region which is not crimped again .

According to the printing device of the present invention, the transfer belt has a non-pressure-bonding area where the ink transferred to the outer peripheral surface of the body of the object to be processed is not pressure-bonded again , at least in the portion wound around the wheel. Even by setting the arrangement of the non-pressure bonding area in advance, the timing of the change in the contact pressure between the transfer belt and the object to be processed is regulated even within the transfer station, so a complicated mechanism can be installed or advanced control can be performed. It is possible to suppress that the ink transferred to the object to be processed is pressed against the transfer member again or the printing is incomplete without performing the above.
As a result, it is possible to maintain high printing quality and obtain high production efficiency even if the processing speed is increased.

According to the configurations of claims 2 and 3, the non-pressure-bonded region can be arranged by slightly adding the configuration to the conventional printing device having the endless transfer belt.
According to the configuration of claim 4, a portion where the transfer belt and the object to be processed are pressure-bonded can be provided on the downstream side of the image region, and at this portion, the surface speed of the transfer belt and the object to be processed can be reliably ensured. It is possible to make them coincide with each other, and it is possible to suppress printing deviation and accurately transfer.

FIG. 1 is a schematic explanatory diagram of a printing apparatus according to an embodiment of the present invention. FIG. 3 is a partial explanatory diagram of a printing apparatus according to an embodiment of the present invention. FIG. 6 is a partial explanatory diagram of a printing apparatus according to another embodiment of the present invention.

As shown schematically in FIG. 1, a printing apparatus 100 according to an embodiment of the present invention includes a transfer belt 150 having an image area 151 on the surface of which an ink image is formed by an inkjet unit 113, and a cylindrical object to be processed. The mandrel 120 that supports the can C that is a rotating body and the mandrel wheel 130 that is a transport unit that moves the plurality of mandrels 120 along the transport path are formed in the image area 151 of the transfer belt 150 by the inkjet unit 113. It has a transfer station 101 for transferring the formed ink image to the outer peripheral surface of the body of the can C.
The transfer belt 150 is wound around the wheel 110 at the transfer station 101.
In the present embodiment, a coating wheel that faces the mandrel wheel 130 on the downstream side of the transfer path of the can C of the transfer station 101 and coats a protective agent on the printing surface transferred to the outer peripheral surface of the body of the can C. 140 is disposed, and a cleaning unit 115 that removes ink remaining on the surface of the transfer belt 150 is provided on the downstream side of the path of the transfer belt 150 of the transfer station 101.

As shown in FIG. 2, the wheel 110 has at least a cylindrical surface that abuts on the image area 151 of the transfer belt 150, and a concave portion 111 provided at a position between the plurality of image areas 151 of the transfer belt 150. have.
Since the transfer belt 150 is wound around the recess 111 in a straight line so as to contact the wheel 110 only at both ends in the circumferential direction, a region having a smaller radius than that wound around the cylindrical surface is formed.
As a result, a non-pressurized area 152 is formed in an area other than the image area 151 of the transfer belt 150 so that the ink transferred to the outer peripheral surface of the body of the can C is not pressed again .

The operation of this embodiment configured as described above will be described.
The can C is carried on the mandrel 120 at a predetermined position on the upstream side of the transfer station 101 of the mandrel wheel 130, and is transported to the transfer station 101 by the rotation of the mandrel wheel 130.
When reaching the transfer station 101, the outer peripheral surface of the body of the can C contacts the transfer belt 150.

The peripheral speed of the outer peripheral surface of the transfer belt 150 wound around the wheel 110 is set to be higher than the peripheral speed of the mandrel wheel 130, and the mandrel 120 and the carried can C are set to 1 while passing through the transfer station 101. While rotating more than rotation, it moves toward the center of the mandrel wheel 130 and is given a predetermined pressing force, and the ink image formed in the image area 151 of the transfer belt 150 is pressure-bonded to the outer peripheral surface of the body of the can C. Transcribed.
The image area 151 on the surface of the transfer belt 150 is formed such that the upstream end surface thereof coincides with the downstream edge of the recess 111, and the image area 151 and the non-pressurized area 152 are adjacent to each other. Even if the transfer of the ink image is completed before the sheet is separated from the transfer station 101, the outer peripheral surface of the body of the can C faces the non-pressurized area 152 of the transfer belt 150, and the pressing force on the surface is reduced, and the printing is performed. The ink transferred to the surface is not pressed against the surface of the transfer belt 150 again.

In this embodiment, the transfer belt 150 has a uniform surface and is simple, and an ink image can be created at an arbitrary position by the inkjet unit 113, and the position of the image region 151 and the recess 111 of the wheel 110 is electrically controlled. It can be done easily.
If the positional relationship between the image area 151 and the concave portion 111 of the wheel 110 is kept constant, the image area 151 may be a specific position on the transfer belt 150, and the ink image may be formed by means other than inkjet.

In a printing apparatus according to another embodiment of the present invention, as schematically shown in FIG. 3, a transfer belt 250 includes a plurality of image regions 251, and a thin non-woven sheet disposed between the image regions 251. It has a crimping area 252 and is wound around a cylindrical wheel 210.
The operation of this embodiment is similar to that of the above-described embodiment.
In the present embodiment, the transfer belt 250 is wound around the wheel 210 at the transfer station, but it may be slid over a stationary member that does not rotate, in which case the stationary member has a constant radius of curvature. It doesn't have to be.
Further, the ink image may be formed by a means other than inkjet, and the transfer belt 250 may be a belt having the thickness of the non-pressure-bonded area 252 and the convex portions forming the image area 251 stacked.

In the embodiment described above, the can C is configured to rotate by the transfer belts 150 and 250. However, the surface of the can C is driven at the transfer station so as to have the same moving speed as the transfer belts 150 and 250. If possible, a separate driving means may be provided.
Further, the transport unit that transports the mandrels 120 and 220 may be configured by other means such as a conveyor instead of the mandrel wheels 130 and 230.

100... Printing device 101... Transfer stations 110, 210... Wheel 111... Recess 113... Inkjet section (ink image forming section)
115... Cleaning part 120... Mandrel 130, 230... Mandrel wheel (transport unit)
140 ... coating wheels 150, 250 ... transfer belts 151, 251 ... image areas 152, 252 ... non-bonding areas C ... cans (processed objects)

Claims (4)

An endless transfer belt having an image area on the surface of which an ink image is formed, a rotatable mandrel for carrying a cylindrical object to be processed, and a carrying unit for moving the plurality of mandrels along a carrying path. ,
A printing apparatus having a transfer station for transferring the ink image formed in the image area of the transfer belt to the outer peripheral surface of the body of the object to be processed,
The transfer belt is wound around a cylindrical wheel that rotates in a range including at least the transfer station,
The printing apparatus according to claim 1, wherein the transfer belt has a non-pressurized area where the ink transferred to the body of the object to be processed is not pressed again at least in a portion wound around the wheel. The printing apparatus according to claim 1, wherein the non-pressure-bonded area of the transfer belt is formed by a recess provided on the outer circumference of the wheel. The printing device according to claim 1, wherein the non-pressure-bonded area of the transfer belt is formed by a portion having a different thickness of the transfer belt. The non-pressure-bonded area of the transfer belt is a part of a portion of the surface of the transfer belt where an ink image is not formed, and is adjacent to an upstream side of the image area of the transfer belt. The printing apparatus according to any one of claims 1 to 3.

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