WO2019230471A1 - Printing device and printing method - Google Patents

Abstract

The present invention addresses the problem of providing a printing device and printing method that make it possible to very rapidly print an inkjet-printed ink image onto cylindrical target objects and thereby achieve high production efficiency. This printing device is characterized by having: a transfer member that comprises a transfer cylinder (110) or an endless transfer belt (310); an inkjet printing station (150) at which an ink image P is formed on the surface of the transfer member by inkjet printing; a transfer station (120) at which the ink image that has been formed on the surface of the transfer member is transferred onto an outer circumferential surface of a body part of cylindrical target objects C; and a transport unit (130) that makes a plurality of mandrels (131) that carry the target objects and are capable of turning move along a transport route. The printing device is also characterized in that, at the transfer station, the ink image is transferred onto the outer circumferential surface of the body part of the target objects from the surface of the transfer member as a result of the transfer member and the target objects being brought into contact while the target objects carried and transported by the mandrels are turned.

Description

Printing apparatus and printing method

The present invention relates to a printing apparatus and a printing method for forming an image by ink jet printing on an outer peripheral surface of a body portion of a cylindrical workpiece.

Conventionally, in curved surface printing on the body of cylindrical objects such as seamless cans made of metal such as aluminum and steel, plate-type printing using a printing plate and inkjet printing or electrophotographic printing without using a plate There is a method using. Examples of the plate-type printing include offset printing in which each color inker plate cylinder is provided with a resin relief plate, each color ink from the resin relief plate is transferred to a blanket, and transferred from the blanket to an object to be processed to form an image. .
However, in plate-type printing, plates are created for each ink color and printed in multiple colors, so it is efficient when mass-producing seamless cans of the same image. Since it is necessary to manufacture a plate, it takes a long time to change the design, and there is a problem that there is no degree of freedom in print design and only limited types of designs can be printed.

On the other hand, since inkjet printing does not require a plate, it does not require plate making costs, and has variable (variable) properties that allow the print design to be freely changed in a short period of time, and can increase the depth of ink. Therefore, there is an advantage that a high-definition image such as a photograph is excellent in reproducibility.
As an apparatus for forming an image by ink jet printing on a body of a cylindrical object to be processed such as a seamless can, Patent Document 1 discloses white (W), yellow (Y), and magenta (M) along a mandrel wheel. Inkjet printing apparatuses are disclosed in which printing stations by inkjet heads corresponding to respective inks of cyan (C) and black (K) are arranged apart from each other. In this ink jet printing apparatus, an object to be processed is carried on a mandrel disposed on a mandrel wheel, and first, the object to be processed is conveyed to the first color (for example, white) printing station by revolving the mandrel wheel. Then, an ink image of the first color (for example, white) is formed by dropping ink from the inkjet head while rotating the object carried on the mandrel at the position where the revolution is stopped. Next, the mandrel wheel is revolved and the object to be processed is transported to the second color (for example, yellow) printing station to form the second color ink image. The single color ink images of the respective colors are sequentially formed and superimposed to form a full color ink image on the outer peripheral surface of the body portion of the object to be processed.

Japanese Patent No. 6111571

However, in the ink jet printing apparatus of Patent Document 1, it is necessary to sequentially convey to each color printing station, which requires a conveyance time, and further, it is necessary to rotate (rotate) the workpiece in each color printing station. . Therefore, since intermittent conveyance is performed in the printing station, there is a problem in that the production speed is low because the speed (printing speed) of printing an ink image on one object to be processed does not increase.

Also, in an inkjet printing apparatus, a plurality of nozzles are provided for each color ink jet head, and all nozzles are often not used evenly when forming an ink image. Ink may dry up and cause clogging, and in addition to ink ejection for forming an ink image, ink ejection that is not used for ink image formation (so-called “discarding”) must be performed at a predetermined timing. There is.
Generally, ink is ejected by moving the ink-jet head out of the printing area. However, in the case of the ink-jet printing apparatus as in Patent Document 1, ink ejection for forming an ink image is performed at a fixed position. In order to perform “discarding”, it is necessary to add a mechanism for moving the ink jet head, which causes a problem that the apparatus becomes complicated.
Further, there is a problem that productivity is hindered because the inkjet head moves at a predetermined timing, and printing is stopped for each time required for the movement.

The present invention solves these problems, and a printing apparatus capable of printing an ink image by ink jet printing at high speed on the outer peripheral surface of a cylindrical portion of a cylindrical object to be processed, resulting in high production efficiency. It is another object of the present invention to provide a printing method.
In addition, another object of the present invention is to enable ink images by inkjet printing to be printed at high speed on the outer peripheral surface of the barrel portion of a cylindrical object to be processed. It is an object to provide a printing method and a printing apparatus that can perform ejection at a predetermined timing and reduce a decrease in production efficiency.

A printing apparatus according to the present invention includes a transfer member including a rotating transfer cylinder or an endless transfer belt that circulates, an ink jet printing station that forms an ink image on the surface of the transfer member by ink jet printing, and the transfer member. A transfer station that transfers the ink image formed on the surface to the outer peripheral surface of the barrel of the cylindrical workpiece, and a transport unit that moves a plurality of self-rotating mandrels carrying the workpiece along the transport path; A printing device comprising:
In the transfer station, the ink image is transferred from the surface of the transfer member to the body of the object by contacting the object to be processed with the transfer member while rotating the object carried on and conveyed by the mandrel. It transfers to the outer peripheral surface of this.
Further, the printing apparatus of the present invention includes a transfer member having an image area that forms an ink image on the surface, which is composed of a rotating transfer cylinder or an endless transfer belt that circulates, and ink jet printing on the surface of the transfer member. An inkjet printing station that forms an image, an image control unit that operates the inkjet printing station, a self-rotating mandrel that supports a cylindrical workpiece, and a transport unit that moves the plurality of mandrels along a transport path A printing apparatus for transferring an ink image formed in an image area of the transfer member to an outer peripheral surface of a body portion of an object to be processed, wherein the image control unit receives an ink image from the inkjet printing station. Ink ejection not used for formation is performed on the surface of the transfer member at a predetermined timing. Characterized in that it is earthenware pots configuration.
In the printing method of the present invention, an ink image is formed by ink jet printing at an ink jet printing station on the surface of a transfer member composed of a rotating transfer cylinder or an endless transfer belt that circulates and is formed on the surface of the transfer member. A printing method in which the ink image is transferred at a transfer station to the outer peripheral surface of a cylindrical portion of a cylindrical object to be processed carried by a plurality of mandrels capable of rotating along a conveyance path,
In the transfer station, the ink image is transferred from the surface of the transfer member to the body of the object by contacting the object to be processed with the transfer member while rotating the object carried on and conveyed by the mandrel. It transfers to the outer peripheral surface of this.
Also, the printing method of the present invention forms an ink image on the surface of a transfer member composed of a rotating transfer cylinder or an endless transfer belt that circulates by ink-jet printing at an ink-jet printing station. A printing method in which a formed ink image is transferred at a transfer station to an outer peripheral surface of a cylindrical portion of a cylindrical object to be processed carried on a plurality of mandrels capable of rotating along a conveyance path, Ink ejection not used for forming the ink image is performed on the surface of the transfer member at a predetermined timing.

According to the printing apparatus according to claim 1 and the printing method according to claim 19 of the present invention, since the ink jet printing station and the transfer station for forming an ink image by ink jet printing are provided on the surface of the transfer member. The formed ink image is collectively transferred onto the outer peripheral surface of the body portion by one rotation of the workpiece by rotating the workpiece at the transfer station while rotating the workpiece at the transfer station. An ink image by ink jet printing can be printed at high speed on the processed material, and high production efficiency can be obtained. Further, since the ink image to be formed is one using ink jet printing, an image having excellent sharpness can be obtained. Further, since ink jet printing does not require a plate, the plate making cost is not required, and a variable (variable) property that allows the print design to be freely changed in a short time is obtained. When the transfer member is a transfer cylinder, an ink heating mechanism such as a heater is provided inside the transfer cylinder, so that there is no need to provide a drying station facing the surface of the transfer cylinder. Can be miniaturized. Also, when the transfer member is composed of a transfer belt, various stations having other functions can be easily installed by adjusting the circumferential length of the transfer belt, and the design of the printing apparatus is high. A degree of freedom is obtained.
According to the configuration of the second aspect of the present invention, since the drying station is provided on the downstream side of the ink jet printing station, the ink image transferred to the object to be processed can be dried to a state suitable for transfer. High transferability can be obtained, and as a result, a high-definition ink image can be printed.
According to the third aspect of the present invention, since a plurality of ink jet printing stations are provided, one ink image is formed by a plurality of ink jet printing stations, that is, by increasing the number of passes, Quality can be improved. In addition, by forming a plurality of ink images close to each other on the transfer member, the number of objects that can be transferred per unit time can be increased, and overall productivity can be increased.
According to the configuration of the fourth aspect of the present invention, since the overcoat processing station is provided, the ink image transferred to the object to be processed at the transfer station is subjected to the overcoat process, whereby the ink image is received. It can be firmly fixed on the processed material. As a result, it is possible to prevent the ink image from being damaged even when it is subjected to various processing in the next step or when it is rubbed by conveyance or the like.
According to the configuration of the fifth aspect of the present invention, since the transport unit includes a mandrel wheel having a plurality of mandrels, the workpiece can be transported easily by the transport unit.
According to the configurations of the sixth and twentieth aspects of the present invention, since the transfer station has the transfer nip portion, the workpiece is rotated while passing through the transfer nip portion, so that the outer peripheral surface of the barrel portion is rotated. Is in rolling contact with the surface of the transfer member to transfer the ink image from the surface of the transfer member to the outer peripheral surface of the body of the object to be processed. As a result, the number of workpieces that can be transferred per unit time can be increased, and the overall productivity can be increased.

According to the configuration of the seventh aspect of the present invention, the transfer nip portion is formed by pressing the pressing cylinder against the object to be processed via the transfer belt, so that the transfer belt is circulated and moved according to the driving of the pressing cylinder. By doing so, wear on the back surface of the transfer belt can be suppressed, so that early deterioration of the transfer belt can be suppressed.
According to the configuration of the eighth aspect of the present invention, the transfer nip portion is formed by pressing the curved structure of the pressing structure with the workpiece through the transfer belt, thereby forming the curved surface of the pressing structure. Since the transfer nip portion can be formed along, the ink image can be easily transferred to the object to be processed by the transport unit using the mandrel wheel.
According to the configuration of the ninth aspect of the present invention, the transfer nip portion is formed by pressing the flat pressing structure with the object to be processed via the transfer belt. Since the transfer nip portion can be formed along the line, the workpiece can be linearly conveyed.
According to the configuration of the tenth aspect of the present invention, since the transfer nip portion is formed between the transfer belt and the object to be processed by the tension of the transfer belt, there is no need to provide a pressing structure. Wear on the back surface of the belt can be suppressed, and early deterioration of the transfer belt can be suppressed.
According to the configurations of the eleventh and twenty-first aspects of the present invention, since a plurality of transfer stations are provided on the circulation path of the transfer member, by performing transfer processing simultaneously and frequently at each transfer station, Even in a configuration in which workpieces are conveyed intermittently instead of continuously, the number of workpieces that can be transferred per unit time can be increased, and overall productivity can be increased. Further, the mechanical structure can be simplified by performing intermittent conveyance.
According to the twelfth and twenty-second aspects of the present invention, since the pre-rotation means for rotating the mandrel in advance is provided, the workpiece is approximately equal to the peripheral speed of the transfer member as the mandrel rotates. It can be transported to the transfer station while being rotated at the same peripheral speed, and as a result, the occurrence of slip due to a large peripheral speed difference between the workpiece and the transfer member during the transfer process is prevented. Therefore, the quality of the ink image transferred to the object to be processed can be maintained high. In addition, it is not necessary to synchronize the peripheral speed of the object to be processed with the transfer member by accelerating the object to be processed by contact with the non-image area where the ink image of the transfer member is not formed. The length between the image areas (non-image areas) can be reduced, and as a result, the number of workpieces that can be transferred per unit time can be increased, thereby improving the overall productivity. it can.

According to the printing apparatus according to claim 13 and the printing method according to claim 23 of the present invention, inkjet printing is performed on the surface of a transfer member comprising a rotating transfer cylinder or an endless transfer belt that circulates in an inkjet printing station. An ink image is formed by the above method, and the ink image formed on the surface of the transfer belt is formed on the outer peripheral surface of the barrel portion of the cylindrical workpiece to be carried on a plurality of mandrels that can be rotated along the conveyance path. By transferring at the transfer station, the object to be processed is transferred to the outer peripheral surface of the body part by one rotation of rotation, so that an ink image by ink jet printing can be printed on the object to be processed at high speed. High production efficiency. In addition, since the ink image to be formed is one using ink jet printing, an image with excellent sharpness can be obtained. Further, since ink jet printing does not require a plate, plate making costs are not required, and variable (variable) properties that can freely change the print design in a short time can be obtained. Further, by providing an ink heating mechanism such as a heater on the back side of the transfer member, it is not necessary to provide a drying station facing the surface of the transfer member, and as a result, the printing apparatus can be miniaturized.
Further, by performing ink ejection not used for forming an ink image on the surface of the transfer member at a predetermined timing, a mechanism for moving the ink jet head is unnecessary, and further, the printing apparatus is simplified and miniaturized. In addition, the moving time of the ink jet head is unnecessary, and the reduction in productivity can be reduced.

According to the configurations of the fourteenth and twenty-fourth aspects of the present invention, the ink ejection that is not used for forming the ink image is performed on the area where the ink image to be transferred is not formed, thereby giving the ink image formation. There is no effect, and a decrease in productivity can be eliminated.
According to the configurations of the fifteenth and twenty-fifth aspects of the present invention, the surface of the transfer member is formed with an ink image formed by projecting a region where an ink image to be transferred is projected from other regions. Ink adhering to the transfer member due to ink ejection not used for the ink can be prevented from adhering to the outer peripheral surface of the body portion of the object to be processed.
According to the configurations of the sixteenth and twenty-sixth aspects of the present invention, the region where the adjacent ink image is formed is formed by performing the ink ejection not used for forming the ink image on the region where the ink image is formed. Even when the inks are close to each other, a sufficient amount of ink can be ejected.
Further, by retracting the cylindrical object to be processed supported on the mandrel at the transfer station to a position where it does not come into contact with the transfer member, the object to be processed is conveyed downstream as an unprocessed object. It is possible to identify and eliminate the ink, and it is possible to perform ink ejection that is not used for forming an ink image with only a loss of one object to be processed without stopping the printing operation, thereby reducing a decrease in productivity.

According to the structure of Claim 17 and Claim 27 of this invention, it has the identification means which identifies the to-be-processed object to which the ink ejection which is not used for formation of an ink image was transferred downstream from a transfer station, An ink image that is not used to form an ink image can be easily identified and eliminated by transferring the object to be processed downstream, and the ink image can be obtained by losing only one object to be processed without stopping the printing operation. Ink ejection that is not used for forming the ink becomes possible, and the reduction in productivity can be reduced.
According to the configurations of the eighteenth and twenty-eighth aspects of the present invention, an identifiable pattern is formed by ink ejection that is not used for forming an ink image, and the identification means identifies the identifiable pattern. By being configured, it is possible to more reliably identify an object to be processed which has been transferred with ink ejection not used for forming an ink image transferred downstream.

1 is an explanatory diagram schematically illustrating an example of a configuration of a printing apparatus according to a first embodiment of the present invention. It is explanatory drawing which shows roughly an example of a structure of the printing apparatus which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows roughly an example of a structure of the printing apparatus which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which shows the modification of the printing apparatus which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which shows another modification of the printing apparatus which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which shows another modification of the printing apparatus which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which shows roughly an example of a structure of the printing apparatus which concerns on the 4th Embodiment of this invention. It is explanatory drawing which shows the modification of the printing apparatus which concerns on the 4th Embodiment of this invention. (A) is explanatory drawing which shows another modification of the printing apparatus which concerns on the 4th Embodiment of this invention, (b) is the figure which looked at (a) from the side. It is explanatory drawing which shows roughly an example of a structure of the printing apparatus which concerns on the 5th Embodiment of this invention. It is explanatory drawing which shows roughly an example of a structure of the printing apparatus which concerns on the 6th Embodiment of this invention.

[Printing Apparatus According to First Embodiment]
Hereinafter, a printing apparatus 100 according to a first embodiment of the present invention will be described with reference to the drawings.
In the printing apparatus 100 according to the first embodiment of the present invention, as shown in FIG. 1, the transfer member is a cylindrical transfer cylinder 110 whose surface rotates along a rotation path. Inkjet printing station 150 for forming ink image P on the surface of 110 by inkjet printing, and ink image P formed on the surface of transfer cylinder 110 are transferred to the outer peripheral surface of the body of can C, which is a cylindrical workpiece. And a transfer unit 130 that moves a plurality of mandrels 131 that can rotate around the transfer path 120 along the transfer path.

[Processed object]
In the present invention, the cylindrical object to be processed specifically includes a metal can, a plastic bottle container, a paper container, or the like having a cylindrical or conical body, and as the object to be processed, , Various surface-treated steel plates such as tin-free steel (TFS), various plated steel plates such as tin plating, light metal plates such as aluminum, and various surface-treated light metal plates obtained by surface treatment such as phosphoric acid chromate treatment, or these metals A resin-coated metal plate with a resin coating made of a thermoplastic resin such as polyester resin on the plate is drawn, drawn and ironed, drawn / redrawed, bent and stretched by drawing / redrawing (stretching), For example, seamless cans manufactured by subjecting to known means such as bending / stretching / ironing by drawing / redrawing, impact processing of light metal plate, etc. That. Moreover, the 3 piece can which passed through processes, such as a tin plate cutting process, roll molding, a can body welding process, and a can body stretch molding, is also mentioned. In addition, the three-piece can may be subjected to paneling molding for forming the can body into an irregular shape such as an ellipse, a square, or an embossed shape, flange portion molding, or the like.
It is preferable that a white coat layer for hiding the ground color of the object to be processed is formed on the outer peripheral surface of the body part of the object to be processed in order to express excellent sharpness in the ink image to be formed. The white coat layer can be formed by, for example, a white coat layer forming unit installed on the upstream side of the transfer station 120 in the conveyance path of the object to be processed. As the white coat layer forming means, for example, a plate-type printing machine that prints a white solid image, a roller that applies white ink to the outer peripheral surface of the body of the object to be processed, and an outer periphery of the body of the object to be processed by spraying white ink A sprayer or the like applied to the surface can be used. Instead of forming the white coat layer, a white (W) solid image may be formed on the surface of the transfer member at the inkjet printing station 150 so as to be transferred to the lowermost layer of the object to be processed. .
Further, an anchor coat layer is preferably formed on the uppermost surface of the workpiece. By forming the anchor coat layer, the transferred ink image by inkjet printing is firmly held and fixed, and the image adhesion to the object to be processed is improved. In addition, ink bleeding can be reduced. The anchor coat layer can be formed by various conventionally known methods by applying a coating solution in which a transparent resin having thermosetting, ultraviolet curable, or electron beam curable properties is dispersed or dissolved in a predetermined solvent. It can be formed by drying and then curing by heating, ultraviolet irradiation, electron beam irradiation or the like. The anchor coat layer can be formed by an anchor coat layer forming means installed on the upstream side of the transfer station 120 in the conveyance path of the workpiece. The anchor coat layer forming means has an apparatus for applying the transparent resin or the like to the outer peripheral surface of the body of the object to be processed. Examples of such an application apparatus include a plate-type printing machine, the application roller, and a spraying machine. Etc. can be used.
The white coat layer is an anchor coat layer having the function of a white coat layer by adding a white pigment such as titanium dioxide to the coating liquid containing the resin exemplified as the resin used for forming the anchor coat layer. It can also be formed.
Furthermore, instead of forming a white coat layer, a resin-coated metal plate having the function of a white coat layer by containing a white pigment in the resin coating forming the resin-coated metal plate as an object to be processed You may use what used.

The workpiece to which the ink image P is transferred at the transfer station 120 of the printing apparatus 100 according to the first embodiment of the present invention may be an image on which an image has been formed in advance. Specifically, the ink image P may be formed by the printing apparatus 100 according to the present invention on an object to be processed on which a solid image or the like is printed by, for example, plate printing. At this time, the ink image P may be formed on an image formed by plate printing formed in advance, or may be formed outside the image.

[Transfer cylinder]
The transfer cylinder 110 constituting the printing apparatus 100 according to the first embodiment of the present invention includes a cylindrical roller in which a base material layer and a release layer are laminated in this order.
The release layer has a hydrophobic release surface on its outer surface in order to separate the ink image P from the surface of the transfer cylinder 110 without any residue and transfer it to the can C.
The release layer is not limited to the one formed on the entire surface of the base material layer, and is formed only on a part of the region including at least an image region on which the predetermined ink image P is formed on the base material layer. It may be a thing. Further, the release layer is not limited to the one that is fixedly formed and repeatedly used, and is formed by applying a coating liquid having peelability to an area including at least the image area for each image formation. It may be.
The base material layer holds the release layer on the surface thereof, and may have flexibility, or may have rigidity. As the base material layer, for example, a two-layer structure of a cylindrical metal substrate and a sponge layer can be used so that the pressure between the can C and the transfer cylinder 110 during transfer is suitable.

The transfer cylinder 110 is driven by a drive source (not shown).

[Inkjet printing station]
The ink jet printing station 150 constituting the printing apparatus 100 according to the first embodiment of the present invention is provided along the surface of the transfer cylinder 110 so as to face the surface of the transfer cylinder 110. Specifically, the inkjet printing station 150 ejects inks of different colors, for example, for yellow (Y color), magenta (M color), cyan (C color), black (K color), and white (W color). These inkjet heads are arranged along the surface of the transfer cylinder 110 in the above order from the upstream side to the downstream side. These ink jet heads are disposed downward or at an angle close to the ink jet so as to drop ink substantially perpendicularly to the surface of the transfer cylinder 110. Each inkjet head of the inkjet printing station 150 is controlled so as to be operated in synchronization to form a predetermined ink image P.
The arrangement order and color of the inkjet heads of the respective colors in the inkjet printing station 150 are not limited to the above example.
Ink jet heads include a piezo method, a thermal method, an electrostatic method, a bubble jet (registered trademark) method, and the like depending on the ink droplet ejection mechanism, but can be used without any particular limitation in the present invention.
The distance between the inkjet head and the surface of the transfer cylinder 110 is, for example, in the range of 0.5 to 4.0 mm from the viewpoint of improving the landing accuracy of ink droplets on the surface of the transfer cylinder 110. If the distance between the inkjet head and the surface of the transfer cylinder 110 is less than 0.5 mm, the inkjet head may come into contact with the surface of the transfer cylinder 110.

In the printing apparatus 100 illustrated in FIG. 1, one inkjet printing station 150 that forms one ink image P is configured using five inkjet heads, but this number may be increased or decreased.
For example, increase or decrease the number of colors (different hues or shades) and increase or decrease the number of inkjet heads accordingly, or increase the number of inkjet heads that discharge droplets of the same color but different from each other Is mentioned. By using a combination of multiple inkjet heads of the same color and different ejection volume, a solid image that requires a high dot density to increase the density or a photo that requires a fine image with small diameter dots An image with excellent sharpness can be printed at high speed so as to satisfy both the image and the character image. In other words, a high density is achieved with an inkjet head with a large amount of one droplet, and a fine image is achieved with an inkjet head that has a small amount of one droplet and can control the size of the dot diameter by the number of drops. This makes it possible to efficiently handle both solid images and photographic images.
In addition, it is possible to increase the number of ink jet heads (the same ink jet heads) having the same color and the same amount of ejected droplets. Specifically, by disposing the same inkjet head apart in the width direction of the transfer member (transfer cylinder 110) (direction perpendicular to the paper surface in FIG. 1), the can C is in the cylinder axis direction of a so-called long can. The ink image P can be accurately formed even when the image is long.

In the printing apparatus 100 according to the first embodiment, a plurality of inkjet printing stations 150 that form one ink image P may be provided along the transfer cylinder 110. That is, a configuration in which a plurality of ink images P can be formed in one rotation of the transfer cylinder 110 can be achieved. The printing apparatus 100 of FIG. 1 is an example in which two inkjet printing stations 150 are provided along the surface of the transfer cylinder 110.

〔ink〕
As the ink used for forming the ink image P, it is possible to use a heat-drying ink, a thermosetting ink, an ultraviolet curable ink, an electron beam curable ink, and the like that are used in conventional ink jet printing. Although the curing means and the temporary baking (temporary curing) means differ depending on the type of ink, the heat drying type ink can be preferably used since the equipment cost relating to baking is particularly low.
There are water-based inks, oil-based inks, solvent-based inks, and the like.

In the printing apparatus 100 according to the first embodiment, a printing station (plate printing station) by plate printing may be provided on the rotation path of the transfer cylinder 110. By providing a plate-type printing station, an image having excellent solid image density reproducibility is obtained by plate-type printing, and an image having excellent sharpness is obtained by inkjet printing. It is assumed that high reproducibility of the image density is obtained in the solid portion and excellent sharpness is obtained in the high definition portion.
The arrangement order of the plate-type printing station and the inkjet printing station 150 on the rotation path of the transfer cylinder 110 is not particularly limited. That is, the order of forming the image by plate printing and the ink image P by inkjet printing is not particularly limited, and whether the plate printing station is arranged upstream or downstream of the inkjet printing station 150 depending on the design or the like. Can be determined as appropriate. In addition, it is particularly preferable to perform the plate-type printing first from the viewpoint of easy positioning and design such as overcoating by inkjet printing.
As a printing method for printing, a printing method using a relief plate, a lithographic plate, or the like conventionally used for printing of seamless cans can be adopted, and offset printing can be particularly preferably used. In offset printing, printing ink is supplied from an ink supply unit to a printing plate (not shown) such as a relief plate on the plate cylinder, and the ink on the printing plate halftone dot and the image area is transferred to the blanket. The transferred ink of each color is transferred to the transfer cylinder 110.
In the case where image formation by plate printing is performed before image formation by ink jet printing, it is preferable that the ink related to plate printing is temporarily cured by pre-baking before forming the ink image P in the ink jet printing station 150. As a result, it is possible to prevent bleeding from occurring at the overlapping portion with the ink image P by ink jet printing and obtain an image with excellent sharpness.

[Drying station]
In the printing apparatus 100 according to the first embodiment, a drying station 160 that dries the ink image P formed in the inkjet printing station 150 is provided between the inkjet printing station 150 and the transfer station 120. The drying station 160 is provided on the downstream side of the inkjet printing station 150 and at a position close to the inkjet printing station 150.
The drying station 160 includes a dryer that dries the ink of the ink image P on the transfer cylinder 110.
Any dryer may be used as long as the ink image P exhibits adhesiveness and has an improved ability to adhere to the can C and be transferred. For example, hot air is supplied according to the type of ink used to form the ink image P. A heater or a light source that emits radiation such as ultraviolet rays can be used. For example, when the ink image P is formed using heat-drying type ink, the ink image P is semi-dried or completely dried by receiving hot air from the heater, so that Transferability is improved. Further, for example, when the ink image P is formed using an ultraviolet curable ink, the ultraviolet curable resin constituting the ink of the ink image P is semi-cured by being irradiated with ultraviolet rays from an ultraviolet light source. Transferability to is improved.
The drying station 160 is not limited to actively providing a dryer for drying the ink image P, and may be configured to naturally dry during transportation by ensuring a large distance between the inkjet printing station 150 and the transfer station 120. . Further, the drying station 160 may be configured such that an ink heating mechanism such as a heater is provided inside the transfer cylinder 110.

The printing apparatus 100 is provided with an adhesive layer forming station for forming an adhesive layer on the ink image P on the downstream side of the ink jet printing station 150 and on the upstream side of the transfer station 120 on the circulation path of the transfer cylinder 110. May be. By providing the adhesive layer forming station, an adhesive layer is formed on the ink image P, so that the transfer property to the can C is improved, and the ink image P of excellent quality can be printed on the can C. .
The arrangement order of the drying station 160 and the adhesive layer forming station on the circulation path of the transfer cylinder 110 is not particularly limited. Specifically, the adhesive layer forming station may be located downstream of the inkjet printing station 150 and upstream of the drying station 160, depending on the need for drying of the adhesive layer. Further, it may be arranged upstream of the transfer station 120.

[Transport unit]
The transport unit 130 constituting the printing apparatus 100 according to the first embodiment of the present invention transports the mandrel 131 carrying the can C along the transport path, has a plurality of mandrels 131, and is horizontally disposed. A mandrel wheel 132 is provided that is attached to the extending rotation shaft and is driven to rotate at a peripheral speed slightly lower than the peripheral speed of the transfer cylinder 110. Specifically, a plurality of mandrels 131 are provided in each of the mandrel formed in the shaft holes formed so that the adjacent distances are equal to each other on the circumference of the predetermined rotation radius of the outer peripheral portion of the mandrel wheel 132. The wheel 132 is rotatably supported around an axis (mandrel axis) parallel to the rotation axis of the wheel 132. In other words, the transport unit 130 is configured such that the can C fitted to the mandrel 131 is continuously transported along the transport path in one direction along with the mandrel 131 when the mandrel wheel 132 is rotationally driven.
A mandrel shaft that supports the mandrel 131 is supported so as to be able to follow and move along the guide shape of a guide groove (not shown), for example. The guide groove is a groove that meanders in a radial direction on the circumference of a predetermined rotation radius around the rotation axis of the mandrel wheel 132 and forms an annular shape as a whole, and as the mandrel wheel 132 rotates, The mandrel shaft is configured to reciprocate in the radial direction of the mandrel wheel 132. That is, a part of the transport path of the mandrel 131 can be meandered without being completely annular. On the other hand, the transfer cylinder 110 is arranged so that a part of a rotation path on which the surface rotates intersects the circumference of a predetermined rotation radius of the mandrel wheel 132, and the transfer path of each mandrel 131 is the transfer cylinder 110. Are configured to be recessed inward in the radial direction of the mandrel wheel 132, and the path of such a trajectory can be obtained by appropriately setting the shape of the guide groove. As a result, the can C fitted to the mandrel 131 comes into contact with the transfer cylinder 110 while being urged toward the transfer cylinder 110 in the middle of its conveyance, and a transfer nip portion N that moves along the outer peripheral surface is formed. .

On the upstream side of the transfer station 120 in the transport path of the mandrel 131, an object supply means (not shown) using, for example, an infeed turret for supplying the can C onto the transport path of the mandrel 131 is provided. .
In addition, the ink image P is transferred to the downstream side of the overcoat processing station 170 in the transport path of the mandrel 131, and the can C subjected to the overcoat processing is transferred to the next process, for example, to be processed using a transfer turret. An object discharging means (not shown) is provided.

[Transfer station]
The transfer station 120 constituting the printing apparatus 100 according to the first embodiment of the present invention has the transfer nip portion N formed as described above. In the transfer nip portion N, pressure is applied to the can C by the transfer cylinder 110 and the transport unit 130. In this transfer nip N, by rotating the can C carried and transported by the mandrel 131 while passing through the transfer nip N, the outer peripheral surface of the barrel is brought into rolling contact with the surface of the transfer cylinder 110. The ink image P is transferred from the surface of the transfer cylinder 110 to the outer peripheral surface of the body portion of the can C.
The length of the transfer nip portion N, that is, the length of movement on the conveyance path while the can C is in contact with the transfer cylinder 110, is the maximum of the printing area where the ink image P is to be printed on the barrel portion of the can C. The circumferential length portion of the can C is equal to or longer than the distance that can be pressed while the can C rotates, and is, for example, equal to or greater than the entire circumferential length of the body portion of the can C. When the transfer nip N is divided and present, the total length of the can C can be pressed while the can C is rotating in the circumferential direction with the maximum circumferential length. What is necessary is just to be more than a distance.
When the length of the transfer nip portion N is too short, since it becomes necessary to rotate the can C while the transfer of the can C by the mandrel wheel 132 is stopped at the transfer station 120, productivity per unit time decreases. .
In the transfer nip portion N, the can C is pressed with a pressure of, for example, 0 to 1000 kPa.

[Preliminary rotation means]
The printing apparatus 100 according to the first embodiment includes preliminary rotation means (not shown) that rotates the mandrel 131 in advance on the upstream side of the transfer station 120 in the conveyance path of the can C in the conveyance unit 130. Yes.
In the preliminary rotating means, the specific configuration is not limited as long as the mandrel 131 is forcibly rotated so that the peripheral speed of the can C is substantially the same as the peripheral speed of the transfer cylinder 110. As the pre-rotating means, for example, there is a mechanism for applying a rotational driving force by bringing the base end portion of the mandrel 131 that does not contact the can C into contact with an endless press pin belt that obtains the driving force from the transfer cylinder 110 and circulates. As disclosed in Japanese Patent No. 4450159, a rack-like fixed gear is provided along the conveyance path on the upstream side of the transfer station 120, and a pre-rotation gear is provided on the mandrel shaft of each mandrel 131 to engage them. By combining them, it is possible to use one having a mechanism for applying a rotational driving force to the mandrel 131.

[Overcoat processing station]
In the printing apparatus 100 according to the first embodiment, an overcoat process is performed on the can C carried by the mandrel 131 and conveyed from the transfer station 120 on the downstream side of the transfer station 120 of the conveyance unit 130. A coat processing station 170 is provided.
The overcoat processing station 170 is provided with, for example, a varnish application roller 171 that forms an overcoat layer made of varnish on the ink image P transferred to the outer peripheral surface of the body portion of the can C in the transfer station 120. The varnish application roller 171 forms a varnish application nip V between the varnish application roller 130 and the mandrel wheel 132 constituting the conveyance unit 130, and moves along the varnish application nip V on the conveyance path while rotating the can C. The varnish is applied by rolling contact with the varnish application roller 171.
Instead of the varnish application roller 171, the overcoat processing station 170 may be provided with a sprayer that supplies varnish to the outer peripheral surface of the body portion of the can C by spraying.
As the varnish, a transparent paint conventionally used as a top coat such as a seamless can can be used, and in particular, a thermosetting transparent paint can be suitably used.

[Washing station]
A cleaning station 140 for cleaning the surface of the transfer cylinder 110 is provided downstream of the transfer station 120 in the rotational direction on the surface of the transfer cylinder 110. The cleaning station 140 includes a cleaning agent spraying unit 141 that supplies the cleaning agent to the surface of the transfer cylinder 110 by spraying, and a region downstream of the region on the transfer cylinder 110 to which the cleaning agent from the cleaning agent spraying unit 141 is supplied. And a scraper 142 provided so as to abut against. The scraper 142 is made of an elastic plate such as a polyethylene terephthalate plate, a polycarbonate plate, or a stainless plate.

Cooling means for cooling the temperature of the transfer cylinder 110 may be provided on the surface of the transfer cylinder 110 downstream of the cleaning station 140 and upstream of the ink jet printing station 150.
The surface temperature of the transfer cylinder 110 is, for example, that the temperature of the region passing through the ink jet printing station 150 is room temperature to 200 ° C., the temperature of the region passing through the drying station 160 is 90 to 300 ° C., and the temperature of the region passing through the transfer station 120. 80-220 ° C.

[Printing method]
The printing method of the present invention is a method of printing the ink image P on the outer peripheral surface of the barrel portion of the can C, which is a cylindrical workpiece, using the above-described printing apparatus of the present invention.
Specifically, first, the ink is printed on the surface of the transfer cylinder 110 that is rotationally driven in one direction (counterclockwise in FIG. 1) by a single color and / or the same color inkjet head at different colors in the inkjet printing station 150. An image is formed, and these are operated in synchronism to be superimposed to form one ink image P. The formed ink image P is transported to the drying station 160 and dried to a state having appropriate adhesiveness, and reaches the transfer station 120 in this state.
On the other hand, the can C fitted and carried on the mandrel 131 on the transport path by the workpiece supply means is in the direction opposite to the transfer cylinder 110 along the transport path defined by the guide groove (clockwise in FIG. 1). 1 and is rotated in the direction opposite to the transfer cylinder 110 (clockwise in FIG. 1) so that the peripheral speed of the can C substantially matches the peripheral speed of the transfer cylinder 110. Then, it is conveyed to the transfer station 120 in a state where the rotation is continued. In the present embodiment, the rotation direction of the transfer cylinder 110 and the circular conveyance direction of the can C by the mandrel wheel 132 are opposite directions, but they may be the same direction. That is, in this embodiment, the can C and the transfer cylinder 110 are transported and moved in the same direction (downward in FIG. 1) at the transfer station 120, but this may be configured to be transported and moved in the opposite direction.
The mandrel 131 and the can C that have reached the transfer nip portion N of the transfer station 120 move along the transport path as the mandrel wheel 132 rotates. At this time, the mandrel 131 is moved according to the shape of the guide groove. Move radially inward. Meanwhile, the outer peripheral surface of the barrel portion of the can C comes into contact with the contact start point on the surface of the transfer cylinder 110 and is pressed. The contact start point may be the upstream edge of the ink image P, or may be a region (non-image region) between the ink image P and the ink image P. Then, the can C that has contacted the surface of the transfer cylinder 110 moves along the conveyance path while rotating while maintaining the contact state. That is, the can C moves from the entrance to the exit of the transfer nip portion N by rolling contact with the transfer cylinder 110 by the movement along the conveyance path and the rotation of the mandrel 131. Along with this rolling contact, the ink image P held on the surface of the transfer cylinder 110 in the transfer nip portion N comes into contact with the outer peripheral surface of the barrel portion of the can C, and the can C is pressed against the transfer cylinder 110. Therefore, the ink image P is transferred from the transfer cylinder 110 to the outer peripheral surface of the body portion of the can C in a lump so as to be wound.
The can C onto which the ink image P has been transferred is transported to the overcoat processing station 170 while being fitted to the mandrel 131, and is transported along the transport path by the mandrel wheel 132 and the mandrel 131 is rotated to rotate the overcoat processing station 170. In contact with the varnish application roller 171 rotated in a direction opposite to the rotation of the mandrel 131 (counterclockwise in FIG. 1), and the outer peripheral surface of the body of the can C is overcoated to form an overcoat layer of varnish. It is formed.
Thereafter, the can C is transferred from the mandrel wheel 132 to the workpiece discharge means and conveyed to the next process. In the next step, for example, when a thermosetting ink is used to form the ink image P, the ink of the ink image P is burned simultaneously with the baking of the varnish, and the ultraviolet curable ink is used to form the ink image P. When used, ultraviolet irradiation is performed. Further, another image may be formed on the outer peripheral surface of the body portion of the can C on which the ink image P is formed by plate-type printing or the like.

After the ink image P is transferred and the can C on which the overcoat processing has been performed is discharged, the mandrel 131 from which the can C has been removed returns to the first object supply means on the transport path again. Further, the transfer cylinder 110 that has passed through the transfer station 120 is supplied with the cleaning agent from the cleaning agent ejecting unit 141 in the cleaning station 140, and after the untransferred ink is removed together with the cleaning agent by the scraper 142, the inkjet printing station 150 again. Return to. By repeating these in synchronization, the can C to which the ink image P has been transferred is continuously obtained.

The transfer speed at which the ink image P is transferred from the transfer cylinder 110 to the can C is set to, for example, 500 pieces / minute, and the peripheral speed of the transfer cylinder 110 is set to, for example, 150 to 200 m / minute.

Since the printing apparatus 100 according to the first embodiment includes the transfer cylinder 110, the inkjet printing station 150, and the transfer station 120, the ink image P formed on the surface of the transfer cylinder 110 is transferred to the transfer station 120. In this case, the can C is brought into contact with the transfer cylinder 110 while rotating, so that the can C is transferred to the outer peripheral surface of the body part by one rotation of rotation. Can be printed with high production efficiency. In addition, since the ink image P to be formed uses ink jet printing, an image with excellent sharpness can be obtained. Further, by providing an ink heating mechanism such as a heater inside the transfer cylinder 110, it is not necessary to provide the drying station 160 facing the surface of the transfer cylinder 110. As a result, the printing apparatus can be downsized. .

Although the printing apparatus 100 according to the first embodiment of the present invention has been specifically described above, the printing apparatus 100 according to the first embodiment is not limited to the above example, and is described in the claims. Various design changes can be made without departing from the present invention.
For example, in the first embodiment described above, it has been described that the can C is transported to the transfer station 120 by the transport unit 130 including the mandrel wheel 132, but the configuration of the transport unit is not limited to this, and the can C is supported. For example, the mandrel may be fixed to a conveyor member and linearly conveyed to the transfer station 120 (linear conveyance).

[Printing Apparatus According to Second Embodiment]
FIG. 2 is an explanatory diagram schematically showing an example of the configuration of a printing apparatus according to the second embodiment of the present invention.
The printing apparatus 200 according to the second embodiment is the first except that a plurality of transfer stations 220 are provided on the surface of the transfer cylinder 110, and a transport unit 230 is provided corresponding to each transfer station 220. The configuration is the same as that of the printing apparatus 100 according to the embodiment. Components having the same configuration as that of the printing apparatus 100 according to the first embodiment are denoted by the same reference numerals.
Specifically, a plurality of, for example, three transfer stations 220 are provided on the surface of the transfer cylinder 110 on the downstream side of the inkjet printing station 150 in the rotational direction. Each transport unit 230 provided corresponding to each transfer station 220 transports the mandrel 231 carrying the can C along the transport path, and has a plurality of mandrels 231 and a horizontally extending rotating shaft. And a mandrel wheel 232 that is pivotally attached to and rotated. Specifically, a plurality of mandrels 231 are provided in each of the shaft holes formed so that the adjacent distances are equal to each other on the circumference of a predetermined rotation radius of the outer periphery of one mandrel wheel 232. The mandrel wheel 232 is rotatably supported around an axis (mandrel axis) parallel to the rotation axis of the mandrel wheel 232. That is, the transport unit 230 is configured such that the can C fitted to the mandrel 231 is transported in one direction along the transport path together with the mandrel 231 when the mandrel wheel 232 is rotationally driven.
The mandrel 231 is configured to be cyclically conveyed on a circumference having a predetermined radius of rotation around the rotation axis of the mandrel wheel 232 as the mandrel wheel 232 rotates. The barrel portion of the can C carried on the mandrel 231 is configured to come into contact with one location (transfer location) on the surface of the transfer cylinder 110 at the end of the transport path of the mandrel 231. A transfer nip portion is not formed between the transport unit 230 and the transfer cylinder 110. The can C may be configured to be pressed to a transfer location on the surface of the transfer cylinder 110 as necessary.

In such a printing apparatus 200 according to the second embodiment, first, an ink image P is formed at the inkjet printing station 150 on the surface of the transfer cylinder 110 that is rotationally driven in one direction (clockwise in FIG. 2). This is dried in the drying station 160 to a state having appropriate tackiness, and reaches the transfer station 220 in this state.
On the other hand, the can C fitted and carried on the mandrel 231 on the transport path by the workpiece supply means is transported in a direction opposite to the transfer cylinder 110 (counterclockwise in FIG. 2) along the transport path. The transfer station 220 is reached.
When the can C reaches the transfer position of the transfer cylinder 110 of the transfer station 220, the transport of the can C by the transport unit 230 is temporarily stopped, and the transfer cylinder 110 is rotated at a peripheral speed synchronized with the peripheral speed of the transfer cylinder 110. Rotation of the mandrel 231 in the opposite direction (counterclockwise in FIG. 2) is started. As a result, the outer peripheral surface of the body portion of the can C comes into contact with the ink image P held on the surface of the transfer cylinder 110, and the can C is pressed against the transfer cylinder 110. And the can C which has contacted the transfer location on the surface of the transfer cylinder 110 rotates while maintaining the contact state. Along with this rotation, the ink image P held on the surface of the transfer cylinder 110 is in contact with the outer peripheral surface of the body portion of the can C, so that the ink image P is separated from the transfer cylinder 110 and wound. The can C is collectively transferred to the outer peripheral surface of the body portion of the can C. Thereafter, the same process as that of the printing apparatus 100 according to the first embodiment is performed on the can C in which the ink image P is transferred to the outer peripheral surface of the body portion.
In the printing apparatus 200 according to the second embodiment, the can C is intermittently transported by the transport unit 230, and the transfer process of one ink image P to the one can C is performed at three simultaneous transfer stations 220. Done. Specifically, three ink images P are formed at the same separation distance as the separation distance of the adjacent transfer stations 220 on the transfer cylinder 110, and these are conveyed to the respective transfer stations 220, while the three conveyances are performed. In the unit 230, the cans C are simultaneously conveyed to the transfer location on the surface of the transfer cylinder 110. Then, at the three transfer stations 220, the transfer cylinder 110 rotates and the can C carried on the mandrel 231 of each transport unit 230 rotates, so that the transfer process of the ink image P is simultaneously performed at three locations.
After discharging the can C onto which the ink image P has been transferred, in each of the three transport units 230, each of the mandrels 231 from which the can C has been removed returns to the first object supply means on the transport path. The transfer cylinder 110 that has passed through the transfer station 220 returns to the inkjet printing station 150 again. By repeating these in synchronization, a plurality of cans C to which the ink image P has been transferred are obtained intermittently.

According to the printing apparatus 200 according to the second embodiment as described above, it is possible to obtain the same effect as that of the printing apparatus 100 according to the first embodiment, and further, transfer onto the surface of the transfer cylinder 110. Since a plurality of stations 220 are provided, the cans C can be transferred per unit time even when the cans C are intermittently transported by performing simultaneous transfer processing at each transfer station 220. Can increase the overall productivity. Further, by performing intermittent conveyance, it is possible to easily perform control related to the conveyance of the object to be processed, the circulating movement of the transfer belt, and the synchronization of the formation of the ink image.

Although the printing apparatus 200 according to the second embodiment of the present invention has been specifically described above, the printing apparatus 200 according to the second embodiment is not limited to the above example, and is described in the claims. Various design changes can be made without departing from the present invention.
For example, in the printing apparatus 200 provided with a plurality of transfer stations 220, the can C has been described as being intermittently conveyed by the conveyance unit 230. However, by providing a transfer nip portion in each of the transfer stations 220, for example, The can C may be configured to be continuously conveyed.

[Printing Apparatus According to Third Embodiment]
FIG. 3 is an explanatory diagram schematically showing an example of the configuration of a printing apparatus according to the third embodiment of the present invention.
The printing apparatus 300 according to the third embodiment has the same configuration as the printing apparatus 100 according to the first embodiment, except that the transfer member is an endless transfer belt 310 that circulates along the circulation path. Have. In FIG. 3, components having the same configuration as that of the printing apparatus 100 according to the first embodiment are denoted by the same reference numerals.

[Transfer belt]
The transfer belt 310 according to this embodiment is an endless belt in which a base material layer and a release layer are laminated in this order from the inside to the outside, and is substantially in the circumferential direction (circulation movement direction of the transfer belt 310). Will not stretch. In the present invention, “substantially does not stretch” means that the change in the distance between any two points on the surface of the transfer belt 310 is less than 1% during use of the transfer belt 310.
The release layer has a hydrophobic release surface on its outer surface in order to separate the ink image P from the surface of the transfer belt 310 without any residue and transfer it to the can C.
The release layer is not limited to the one formed on the entire surface of the base material layer, and is formed only on a part of the region including at least an image region on which the predetermined ink image P is formed on the base material layer. It may be a thing. Further, the release layer is not limited to the one that is fixedly formed and repeatedly used, and is formed by applying a coating liquid having peelability to an area including at least the image area for each image formation. It may be.
The base material layer holds the release layer on the surface thereof, and may have flexibility, or may have rigidity. As the base material layer, for example, a two-layer structure of a base fabric layer and a sponge layer can be used so that the pressure between the can C and the transfer belt 310 during transfer is suitable.
In the transfer belt 310, an inner layer for controlling the frictional resistance with the pressing cylinder 112 may be further laminated on the inner side of the base material layer.

The transfer belt 310 is stretched with a predetermined tension by a pressing cylinder 112 and a support roller 113 and is rotatably supported. The transfer belt 310 may be configured to be driven by a driving source (not shown) independently of the pressing cylinder 112, or may be configured to be driven by the rotational driving of the pressing cylinder 112.
The pressing cylinder 112 urges the release layer of the transfer belt 310 toward the can C transported to a transfer nip portion N, which will be described later, and brings it into contact with the can C.

The ink jet printing station 150 according to the present embodiment is provided in a horizontal arrangement portion of the transfer belt 310 along the circulation path of the transfer belt 310. Specifically, the inkjet printing station 150 ejects inks of different colors, for example, for yellow (Y color), magenta (M color), cyan (C color), black (K color), and white (W color). The inkjet heads are arranged in the above order from the upstream side to the downstream side along the horizontal arrangement portion of the transfer belt 310 in the circulation path. These ink jet heads are disposed downward so as to drop ink substantially perpendicularly to the surface of the transfer belt 310. Each inkjet head of the inkjet printing station 150 is controlled so as to be operated in synchronization to form a predetermined ink image P. By disposing the ink jet printing station 150 in the horizontal arrangement portion of the transfer belt 310, ink droplets used for ink jet printing can be ejected in the direction of gravity, so printing controllability is high and, as a result, good An accurate ink image can be formed.
In the printing apparatus 300 according to the third embodiment, a plurality of inkjet printing stations 150 that form one ink image P may be provided along the transfer belt 310. That is, a configuration in which a plurality of ink images P can be formed in one circulation of the transfer belt 310 can be achieved. The printing apparatus 100 of FIG. 1 is an example in which two inkjet printing stations 150 are provided along the circulation movement direction of the transfer belt 310.
In the transfer station 120 according to the present embodiment, a transfer nip portion N is formed in which the can C fitted to the mandrel 131 moves along the outer peripheral surface of the pressing cylinder 112 via the transfer belt 310 in the middle of the transfer. .
In the transfer nip portion N, pressure is applied to the can C by the pressing cylinder 112 and the transport unit 130 via the transfer belt 310.

According to the printing apparatus 300 according to the third embodiment, since the endless transfer belt 310, the inkjet printing station 150, and the transfer station 120 are included, the ink image P formed on the surface of the transfer belt 310 is By bringing the can C into contact with the transfer belt 310 while rotating the can C at the transfer station 120, the can C is transferred to the outer peripheral surface of the body portion by one rotation of the can C, so that an ink image by ink jet printing is applied to the can C. P can be printed at high speed, and high production efficiency can be obtained. In addition, since the ink image P to be formed uses ink jet printing, an image with excellent sharpness can be obtained. Further, by providing a horizontal arrangement portion on the transfer belt 310 and arranging the ink jet printing station 150 on the horizontal arrangement portion, it is possible to discharge ink droplets used for ink jet printing in the direction of gravity, so that controllability of printing is achieved. As a result, the ink image P with good accuracy can be formed. Further, by adjusting the length of the transfer belt 310 in the circumferential direction, various stations having other functions can be easily installed, and the printing apparatus 100 can have a high degree of design freedom.

Although the printing apparatus 300 according to the third embodiment of the present invention has been specifically described above, the printing apparatus 300 according to the third embodiment is not limited to the above example, and is described in the claims. Various design changes can be made without departing from the present invention.
For example, in the above-described embodiment, the transfer nip portion N formed by the transport unit and the transfer belt is described as being formed via the transfer belt 310 between the transport unit 130 and the pressure cylinder 112 that is rotationally driven. However, the configurations of the transport unit, the transfer belt, and the transfer nip portion formed by these are not limited thereto.
For example, as shown in FIG. 4, the transfer nip NA may be formed via the transfer belt 310 between the transport unit 130 and the pressing structure 112 </ b> A having a curved surface. Specifically, the printing apparatus 301 according to this modification uses a pressing structure 112A having a curved surface instead of the pressing cylinder 112 in the printing apparatus 300 according to the third embodiment, and uses the curved surface on the back surface of the transfer belt 310. The printer has the same configuration as that of the printing apparatus 300 according to the third embodiment except that the transfer belt 310 is stretched while being in contact and fixed and the transfer belt 310 slides. In FIG. 4, reference numerals 114a to 114d denote support rollers for stretching the transfer belt 310. In FIG. 4, the same reference numerals are used to indicate the same configuration as that of the printing apparatus 300 according to the third embodiment.

For example, as shown in FIG. 5, the transfer nip NB may be formed between the transport unit 130 and the pressing structure 112B having a flat surface via a transfer belt 310. Specifically, in the printing apparatus 302 according to this modification, the transfer belt 310 is stretched between four support rollers 114a to 114d, and the transfer belt 310 between the two adjacent support rollers 114a and 114b. A pressing structure 112B having a flat surface in contact with the back surface is fixedly arranged. The transfer belt 310 slides in contact with the plane of the pressing structure 112B. On the other hand, as the transport unit 180, a plurality of mandrels 131 are transported along the transport path, and the transport paths of each mandrel 131 are transported linearly along the pressing structure 112 </ b> B at locations corresponding to the transfer belt 310. Is used. As a result, a transfer nip NB is formed in which the can C fitted to the mandrel 131 moves along the plane of the pressing structure 112B via the transfer belt 310 in the middle of its conveyance. In FIG. 5, components having the same configuration as that of the printing apparatus 300 according to the third embodiment are denoted by the same reference numerals.

For example, as shown in FIG. 6, the transfer nip portion NC may be formed between the transport unit 130 and the transfer belt 310 having no structure on the back surface. Specifically, in the printing apparatus 303 according to this modified example, the transfer belt 310 is stretched around the four support rollers 114 a to 114 d, and the conveyance path of each mandrel 131 corresponds to the transfer belt 310. Specifically, the can C is conveyed while being applied with pressure by the tension of the transfer belt 310 along the surface of the transfer belt 310 between two adjacent support rollers 114a and 114b. As a result, a transfer nip portion NC is formed in which the can C fitted to the mandrel 131 moves along the surface of the transfer belt 310 during the conveyance thereof. In FIG. 6, components having the same configuration as that of the printing apparatus 300 according to the third embodiment are denoted by the same reference numerals.

[Printing Apparatus According to Fourth Embodiment]
FIG. 7 is an explanatory diagram schematically showing an example of the configuration of a printing apparatus according to the fourth embodiment of the present invention.
The printing apparatus 400 according to the fourth embodiment is the third configuration except that a plurality of transfer stations 220 are provided on the circulation path of the transfer belt 310, and a transport unit 230 is provided corresponding to each transfer station 220. The configuration is the same as that of the printing apparatus 300 according to the embodiment. Components having the same configuration as that of the printing apparatus 300 according to the third embodiment are denoted by the same reference numerals.
Specifically, the transfer belt 310 is stretched around four support rollers 114a to 114d and arranged to circulate and move in one direction along the circulation path. A plurality of, for example, three transfer stations 220 are provided on the downstream side of 150. Each transport unit 230 provided corresponding to each transfer station 220 transports the mandrel 231 carrying the can C along the transport path, and has a plurality of mandrels 231 and a horizontally extending rotating shaft. And a mandrel wheel 232 that is pivotally attached to and rotated. Specifically, a plurality of mandrels 231 are provided in each of the shaft holes formed so that the adjacent distances are equal to each other on the circumference of a predetermined rotation radius of the outer periphery of one mandrel wheel 232. The mandrel wheel 232 is rotatably supported around an axis (mandrel axis) parallel to the rotation axis of the mandrel wheel 232. That is, the transport unit 230 is configured such that the can C fitted to the mandrel 231 is transported in one direction along the transport path together with the mandrel 231 when the mandrel wheel 232 is rotationally driven.
The mandrel 231 is configured to be cyclically conveyed on a circumference having a predetermined radius of rotation around the rotation axis of the mandrel wheel 232 as the mandrel wheel 232 rotates. The body portion of the can C carried by the mandrel 231 is in contact with one location (transfer location) on the surface of the transfer belt 310 at the top (upper end in FIG. 7) of the transport path of the mandrel 231. . A pressing cylinder 118 is provided on the back surface of the transfer location on the front surface of the transfer belt 310. That is, a transfer nip portion is not formed between the transport unit 230 and the transfer belt 310. The can C may be configured to be pressed to a transfer location on the surface of the transfer belt 310 as necessary. At this time, the pressing cylinder 118 may be biased toward the transfer belt 310, or the mandrel 231 (can C) may be biased toward the transfer belt 310.

In such a printing apparatus 400 according to the fourth embodiment, first, an ink image P is formed at the inkjet printing station 150 on the surface of the transfer belt 310 that is circulated in one direction (clockwise in FIG. 7). This is dried in the drying station 160 to a state having appropriate tackiness, and reaches the transfer station 220 in this state.
On the other hand, the can C, which is fitted on and supported by the mandrel 231 on the conveyance path by the workpiece supply means, is cyclically conveyed in the direction opposite to the transfer belt 310 (counterclockwise in FIG. 7) along the conveyance path. The transfer station 220 is reached.
When the can C reaches the transfer position of the transfer belt 310 of the transfer station 220, the transport of the can C by the transport unit 230 is once stopped, and the transfer belt 310 is synchronized with the peripheral speed of the transfer belt 310. Rotation of the mandrel 231 in the opposite direction (counterclockwise in FIG. 7) is started. As a result, the outer peripheral surface of the body of the can C comes into contact with the ink image P held on the surface of the transfer belt 310, and the can C is pressed against the transfer belt 310. Then, the can C that has contacted the transfer location on the surface of the transfer belt 310 rotates while maintaining the contact state. Along with this rotation, the ink image P held on the surface of the transfer belt 310 is in contact with the outer peripheral surface of the body portion of the can C, so that the ink image P is separated from the transfer belt 310 and wound. The can C is collectively transferred to the outer peripheral surface of the body portion of the can C. Thereafter, the same process as that of the printing apparatus 300 according to the third embodiment is performed on the can C in which the ink image P is transferred to the outer peripheral surface of the body portion.
In the printing apparatus 400 according to the fourth embodiment, the can C is intermittently transported by the transport unit 230, and the transfer process of one ink image P to the one can C is frequently performed at the three transfer stations 220. Done. Specifically, three ink images P are formed on the transfer belt 310 through the same separation distance as the separation distance of the adjacent transfer stations 220, and these are conveyed to the respective transfer stations 220, while the three conveyances are performed. In the unit 230, the cans C are simultaneously conveyed to the transfer location on the surface of the transfer belt 310. In the three transfer stations 220, the transfer belt 310 circulates and the cans C carried on the mandrels 231 of the respective transport units 230 rotate, whereby the transfer process of the ink image P is simultaneously performed at three locations. .
After discharging the can C onto which the ink image P has been transferred, in each of the three transport units 230, each of the mandrels 231 from which the can C has been removed returns to the first object supply means on the transport path. Further, the transfer belt 310 that has passed through the transfer station 220 returns to the inkjet printing station 150 again. By repeating these in synchronization, a plurality of cans C to which the ink image P has been transferred are obtained intermittently.

According to the printing apparatus 400 according to the fourth embodiment as described above, it is possible to obtain the same effect as that of the printing apparatus 300 according to the third embodiment, and further transfer onto the circulation path of the transfer belt 310. Since a plurality of stations 220 are provided, the cans C can be transferred per unit time even when the cans C are intermittently transported by performing simultaneous transfer processing at each transfer station 220. Can increase the overall productivity. Further, by performing intermittent conveyance, it is possible to easily perform control related to the synchronization of conveyance of the can C, circulation movement of the transfer belt 310, and formation of the ink image P.

Although the printing apparatus 400 according to the fourth embodiment of the present invention has been specifically described above, the printing apparatus 400 according to the fourth embodiment is not limited to the above example, and various modifications are made. be able to.
For example, in the above-described fourth embodiment, the conveyance unit 230 corresponding to each of the plurality of transfer stations 220 has been described. However, the configuration of the conveyance unit is not limited to this, and for example, as illustrated in FIG. As described above, the transport unit 280 has a configuration in which the mandrel 231 carrying the can C is fixed to, for example, the conveyor member 233 along the circulation movement direction of the transfer belt 310 and is transported linearly (linear transport). May be. Specifically, the printing apparatus 401 according to this modified example is the same as that of the printing apparatus 400 according to the fourth embodiment, except that the conveyance unit 280 related to one linear conveyance is used instead of the three conveyance units 230 in the printing apparatus 400 according to the fourth embodiment. 4 has the same configuration as the printing apparatus 400 according to the fourth embodiment. In FIG. 8, components having the same configuration as that of the printing apparatus 400 according to the fourth embodiment are denoted by the same reference numerals. In FIG. 8, the pressing cylinder 118 is illustrated as being biased toward the transfer belt 310, but is not limited thereto, and the mandrel 231 (can C) is biased toward the transfer belt 310. May be.

In the printing apparatus 401 according to such a modification, first, an ink image P is formed at the inkjet printing station 150 on the surface of the transfer belt 310 that is circulated and moved in one direction (clockwise in FIG. 8). In the drying station 160, the ink image P is dried to a state having appropriate adhesiveness, and the ink image P formed on the transfer belt 310 in this state reaches the transfer station 220.
On the other hand, the can C fitted and carried on the mandrel 231 of the transport unit 280 is transported in the same direction as the transfer belt (leftward in FIG. 8) at one side facing the transfer belt 310 along the transport path. The transfer station 220 is reached.
When the can C reaches the transfer position of the transfer belt 310 of the transfer station 220, the transport of the can C by the transport unit 280 is temporarily stopped, and the transfer belt 310 is synchronized with the circulation movement speed of the transfer belt 310. Rotation of the mandrel 231 in the opposite direction (counterclockwise in FIG. 8) is started. As a result, the outer peripheral surface of the body of the can C comes into contact with the ink image P held on the surface of the transfer belt 310, and the can C is pressed against the transfer belt 310. Then, the can C that has contacted the transfer location on the surface of the transfer belt 310 rotates while maintaining the contact state. Along with this rotation, the ink image P held on the surface of the transfer belt 310 is in contact with the outer peripheral surface of the body portion of the can C, so that the ink image P is separated from the transfer belt 310 and wound. The can C is collectively transferred to the outer peripheral surface of the body portion of the can C. Thereafter, the same process as that of the printing apparatus 300 according to the third embodiment is performed on the can C in which the ink image P is transferred to the outer peripheral surface of the body portion.
In the printing apparatus 401 according to this modified example, the can C is intermittently transported by the transport unit 280, and the transfer process of one ink image P to the one can C is performed simultaneously and frequently in the three transfer stations 220. Is called. Specifically, three ink images P are formed on the transfer belt 310 through the same separation distance as the separation distance of the adjacent transfer stations 220, and these are conveyed to the respective transfer stations 220, while the conveyance unit 280. At the same time, the cans C are simultaneously conveyed to a transfer location on the surface of the transfer belt 310. At the three transfer stations 220, the transfer belt 310 circulates and the cans C carried on the respective mandrels 231 rotate, whereby the transfer of the ink image P is performed at three locations.
After discharging the can C to which the ink image P has been transferred, in the transport unit 280, each of the mandrels 231 from which the can C has been removed returns again to the first object supply means on the transport path. Further, the transfer belt 310 that has passed through the transfer station 220 returns to the inkjet printing station 150 again. By repeating these in synchronization, a plurality of cans C to which the ink image P has been transferred are obtained intermittently.

For example, as shown in FIG. 9, the transport unit 290 is provided such that the mandrel shaft of the mandrel 231 extends in the normal direction of the mandrel wheel 232, and the mandrel wheel 232 rotates in the transfer belt 310. The cylindrical axis of the can C conveyed to the transfer station 220 (the central axis of the barrel) is arranged so as to extend in the same direction as the surface of the transfer belt 310. May be. The printing apparatus 402 may be configured such that the pressing cylinder 118 is biased toward the transfer belt 310, and may be configured such that the mandrel 231 (can C) is biased toward the transfer belt 310. In FIG. 9, components having the same configuration as that of the printing apparatus 400 according to the fourth embodiment are denoted by the same reference numerals.

In the printing apparatus 402 according to such a modified example, first, an ink image P is formed at the ink jet printing station 150 on the surface of the transfer belt 310 that is circulated and moved in one direction (clockwise in FIG. 9). In the drying station 160, the film is dried to a state having an appropriate tackiness, and reaches the transfer station 220 in this state.
On the other hand, the can C that is fitted and supported on the mandrel 231 on the transport path by the workpiece supply means is transported along the transport path to the transfer station 220.
When the can C reaches the transfer position of the transfer belt 310 of the transfer station 220, the transport of the can C by the transport unit 290 is temporarily stopped, and the transfer belt 310 is synchronized with the peripheral speed of the transfer belt 310. Rotation of the mandrel 231 in the opposite direction (counterclockwise in FIG. 9) is started. As a result, the outer peripheral surface of the body of the can C comes into contact with the ink image P held on the surface of the transfer belt 310, and the can C is pressed against the transfer belt 310. Then, the can C that has contacted the transfer location on the surface of the transfer belt 310 rotates while maintaining the contact state. Along with this rotation, the ink image P held on the surface of the transfer belt 310 is in contact with the outer peripheral surface of the body portion of the can C, so that the ink image P is separated from the transfer belt 310 and wound. The can C is collectively transferred to the outer peripheral surface of the body portion of the can C. Thereafter, the same process as that of the printing apparatus 300 according to the third embodiment is performed on the can C in which the ink image P is transferred to the outer peripheral surface of the body portion.
In the printing apparatus 402 according to this modified example, the can C is intermittently transported by the transport unit 290, and the transfer processing of one ink image P to the one can C is performed simultaneously and frequently in the three transfer stations 220. Is called. Specifically, three ink images P are formed on the transfer belt 310 through the same separation distance as the separation distance of the adjacent transfer stations 220, and these are conveyed to the respective transfer stations 220, while the three conveyances are performed. In the unit 290, the cans C are simultaneously transported to a transfer location on the surface of the transfer belt 310. At the three transfer stations 220, the transfer belt 310 circulates and the cans C carried on the mandrels 231 of the respective transport units 290 rotate, whereby the transfer of the ink image P is performed at three locations.
After discharging the can C to which the ink image P has been transferred, in the three transport units 290, each of the mandrels 231 from which the can C has been removed returns to the first object supply means on the transport path. Further, the transfer belt 310 that has passed through the transfer station 220 returns to the inkjet printing station 150 again. By repeating these in synchronization, a plurality of cans C to which the ink image P has been transferred are obtained intermittently.

In the above-described printing apparatuses 400, 401, and 402 having a plurality of transfer stations 220 on the circulation path of the transfer belt 310, the can C is described as being intermittently conveyed by the conveyance units (230, 280, and 290). Further, by providing a transfer nip portion in each of the transfer stations 220, the can C can be configured to be continuously conveyed.

[Printing Apparatus According to Fifth Embodiment]
FIG. 10 is an explanatory diagram schematically showing an example of the configuration of a printing apparatus according to the fifth embodiment of the present invention.
In addition to ink ejection for forming an ink image, the printing apparatus 500 according to the fifth embodiment applies ink that is not used to form an ink image to each inkjet head of the inkjet printing station 150 at a predetermined timing. The printer has the same configuration as that of the printing apparatus 100 according to the first embodiment except that an image control unit 190 that performs ejection (so-called “discarding”) is provided. Components having the same configuration as that of the printing apparatus 100 according to the first embodiment are denoted by the same reference numerals.

Each ink jet head of the ink jet printing station 150 according to the present embodiment is controlled to operate in synchronism in order to form a predetermined ink image P according to a command from the image control unit 190.
In addition to ink ejection for forming an ink image, the image control unit 190 ejects ink that is not used for ink image formation (so-called “" It is set to perform “Discard”.
The timing for performing the discarding is optimally determined by the image control unit 190 in accordance with the ejection amount and ejection interval from the plurality of nozzles of each inkjet head.
If the interval between the ink images P is somewhat large, the discarding is performed between the ink images P, so that the discarding is performed at a position not in contact with the can C, and the printing productivity is completely affected. There is nothing.
In addition, when the position of the ink image P formed on the surface of the transfer cylinder 110 is always designed to be the same position, the area where the ink image P to be transferred is formed on the surface of the transfer cylinder 110. By projecting from the other areas, the can C can be more reliably prevented from touching the discarded ink.
On the other hand, if the position of the ink image P formed on the surface of the transfer cylinder 110 is not constant, discarding is performed instead of forming the ink image P at a predetermined timing.
In this case, the can C to which the discarded ink is transferred is generated, but it is sufficient to eliminate only the can after the printing while the production process is continuously operated, and the influence on the printing productivity is negligible. is there.
The image control unit 190 forms an image with a highly discriminating pattern with discarded ink, so that the can can be easily excluded visually or by a sensor or the like.
Furthermore, by providing the mandrel wheel 132 with a shift means for moving the can C so that it does not come into contact with the transfer cylinder 110 at a transfer station 120 described later, only the can C whose timing coincides with the area where the discarding operation has been performed, It is possible to make the state where the ink is not transferred, and this may increase the identification of the can C to be excluded.

In the transfer station 120 according to the present embodiment, although not shown, the mandrel wheel 132 is provided with shift means for actively moving the mandrel 131 inward in the radial direction, and the surface of the transfer cylinder 110 on which the disposal is performed is the can C. The mandrel 131 may be moved radially inward to the position where the can C does not contact the transfer cylinder 110 at the transfer station 120 only when the position is synchronized with the transfer cylinder 120.
In the cleaning station 140 according to the present embodiment, ink on the surface of the transfer cylinder 110 that has been discarded is removed.

The printing apparatus 500 according to the fifth embodiment of the present invention has been specifically described above. However, the printing apparatus 500 according to the fifth embodiment is not limited to the above example, and is described in the claims. Various design changes can be made without departing from the present invention.
For example, a printing apparatus having a transfer nip portion configured as shown in FIGS. 4 to 6 may be used.

[Printing Apparatus According to Sixth Embodiment]
FIG. 11 is an explanatory diagram schematically showing an example of the configuration of a printing apparatus according to the sixth embodiment of the present invention.
The printing apparatus 600 according to the sixth embodiment is the same as that of the first embodiment except that the transfer member is an endless transfer belt 310 that circulates along the circulation path.
The transfer belt 310 constituting the printing apparatus 600 according to the sixth embodiment of the present invention is the same as the transfer belt 310 according to the third embodiment.
The transfer belt 310 is stretched with a predetermined tension by a pressing cylinder 112 and a support roller 113 and is rotatably supported. The transfer belt 310 may be configured to be driven by a driving source (not shown) independently of the pressing cylinder 112, or may be configured to be driven by the rotational driving of the pressing cylinder 112.
The pressing cylinder 112 urges the release layer of the transfer belt 310 toward the can C transported to a transfer nip portion N, which will be described later, and brings it into contact with the can C.

In each of the fifth and sixth embodiments described above, the plurality of mandrels are configured to be capable of positively changing the position of the mandrel in the width direction (the front and back direction in the figure) or the width direction of the held can. As a result, the position where the can contacts the transfer member is changed in the width direction, the position of the end of the can contacting the transfer member is changed, and the end of the can repeatedly contacts at the same position. It is possible to prevent deformation and deterioration that occur in some cases.
At that time, the position in the width direction of the ink image formed by the image control unit at the ink jet printing station may be calculated by setting a change in the position in the width direction of the mandrel in advance. It may be calculated from the obtained position information.

Although the printing apparatus 600 according to the sixth embodiment of the present invention has been specifically described above, the printing apparatus 600 according to the sixth embodiment is not limited to the above example, and is described in the claims. Various design changes can be made without departing from the present invention.
For example, a printing apparatus having the configuration shown in FIGS. 8 and 9 may be used.

Since the printing apparatus of the present invention can print an image by inkjet printing at high speed, it can be suitably used for a cylindrical can such as a seamless can used for a beverage container or the like that requires decoration and productivity. can do.

100, 200, 300, 301, 302, 303, 400, 401, 402, 500, 600 Printing device 110 Transfer cylinder 112 Press cylinder 112A, 112B Press structure 113 Support roller 114a-114d Support roller 118 Press cylinder 120, 220 Transfer Stations 130, 180, 230, 280, 290 Transport units 131, 231 Mandrels 132, 232 Mandrel wheels 140 Cleaning station 141 Cleaning agent jetting unit 142 Scraper 150 Inkjet printing station 160 Drying station 170 Overcoat processing station 171 Varnish application roller 190 Image control 233 Conveyor member 310 Transfer belt C Cans N, NA, NB, NC Transfer nip P Ink image V Varnish application nip

Claims (28)

A transfer member composed of a rotating transfer cylinder or an endless transfer belt that circulates, an ink jet printing station that forms an ink image by ink jet printing on the surface of the transfer member, and an ink image formed on the surface of the transfer member A printing station having a transfer station that transfers the cylindrical object to the outer peripheral surface of the barrel of the object to be processed, and a transport unit that moves a plurality of self-rotating mandrels carrying the object to be processed along the transport path. ,
In the transfer station, the ink image is transferred from the surface of the transfer member to the body of the object by contacting the object to be processed with the transfer member while rotating the object carried on and conveyed by the mandrel. The printing apparatus is characterized by being transferred to the outer peripheral surface of the printer. The printing apparatus according to claim 1, wherein a drying station for drying an ink image formed in the inkjet printing station is provided between the inkjet printing station and the transfer station. The printing apparatus according to claim 1, wherein a plurality of the ink jet printing stations are provided. An overcoat process is performed on the ink image transferred to the outer peripheral surface of the body portion of the workpiece carried on the mandrel and transported from the transfer station, on the downstream side of the transfer station of the transport unit. The printing apparatus according to any one of claims 1 to 3, wherein a station is provided. 5. The printing apparatus according to claim 1, wherein the transport unit includes a mandrel wheel having the plurality of mandrels. The transfer station has a transfer nip portion where pressure is applied to an object to be processed by the transfer member and the transport unit,
In the transfer nip portion, by rotating the workpiece carried and transported on the mandrel while passing through the transfer nip portion, the outer peripheral surface of the body portion is brought into rolling contact with the surface of the transfer member. The ink image is transferred from the surface of the transfer member to the outer peripheral surface of the body portion of the workpiece,
6. The printing apparatus according to claim 1, wherein the transport unit is configured to continuously transport a plurality of objects to be processed carried on the mandrels. When the transfer member is composed of an endless transfer belt that circulates,
The transfer station has a transfer nip portion where pressure is applied to an object to be processed by the transfer member and the transport unit,
The transfer nip portion is formed between the transport unit and a rotationally driven pressure cylinder that stretches the transfer belt, with the transfer belt interposed therebetween. A printing apparatus according to claim 1. When the transfer member is composed of an endless transfer belt that circulates,
The transfer station has a transfer nip portion where pressure is applied to an object to be processed by the transfer member and the transport unit,
The transfer nip portion is formed between the transport unit and a pressing structure having a curved surface that stretches the transfer belt via the transfer belt. A printing apparatus according to claim 1. When the transfer member is composed of an endless transfer belt that circulates,
The transfer station has a transfer nip portion where pressure is applied to an object to be processed by the transfer member and the transport unit,
The printing apparatus according to any one of claims 1 to 6, wherein the transfer nip portion is formed via the transfer belt between the transport unit and a pressing structure having a flat surface. When the transfer member is composed of an endless transfer belt that circulates,
The transfer station has a transfer nip portion where pressure is applied to an object to be processed by the transfer member and the transport unit,
The printing apparatus according to any one of claims 1 to 6, wherein the transfer nip portion is formed between the transport unit and the transfer belt having no structure on the back surface. 11. The printing apparatus according to claim 1, wherein a plurality of transfer stations are provided on a circulation path of the transfer member. 12. The printing apparatus according to claim 1, further comprising a pre-rotation unit that rotates the mandrel in advance on the upstream side of the transfer station of the transport unit. An image control unit for operating the inkjet printing station;
The image control unit is configured to perform ink ejection not used for forming an ink image from the ink jet printing station to the surface of the transfer member at a predetermined timing. Item 13. The printing apparatus according to any one of Items 12. 14. The printing apparatus according to claim 13, wherein the image control unit is configured to perform ink ejection not used for forming the ink image on a region where a transfer ink image is not formed. 15. The printing apparatus according to claim 13, wherein an area where an ink image to be transferred is formed protrudes from the surface of the transfer member as compared with other areas. The image control unit is configured to perform ink ejection not used for forming the ink image on a region where the ink image is formed,
The printing apparatus according to claim 15, wherein the transport unit includes a shift unit configured to retract a cylindrical workpiece to be processed supported on the mandrel to a position where the transfer unit does not come into contact with the transfer member. . The image control unit is configured to perform ink ejection not used for forming the ink image on a region where the ink image is formed,
The printing apparatus according to claim 15, further comprising an identification unit that identifies an object to be processed on which ink ejection not used for forming the ink image is transferred downstream of the transfer station. The image control unit is configured to form an identifiable pattern by ink ejection not used for forming the ink image.
The printing apparatus according to claim 17, wherein the identification unit is configured to identify the identifiable pattern. An ink image is formed by ink jet printing at an ink jet printing station on the surface of a transfer member composed of a rotating transfer cylinder or an endless transfer belt that circulates, and the ink image formed on the surface of the transfer member is transferred to the transfer path. A printing method for transferring at a transfer station to the outer peripheral surface of a cylindrical portion of a cylindrical object to be processed carried by a plurality of mandrels capable of rotating along
In the transfer station, the ink image is transferred from the surface of the transfer member to the body of the object by contacting the object to be processed with the transfer member while rotating the object carried on and conveyed by the mandrel. The printing method characterized by transferring to the outer peripheral surface of this. The transfer station has a transfer nip portion where pressure is applied to an object to be processed by the transfer member and the transport unit,
In the transfer nip portion, by rotating the workpiece carried and transported on the mandrel while passing through the transfer nip portion, the outer peripheral surface of the body portion is brought into rolling contact with the surface of the transfer member. The ink image is transferred from the surface of the transfer member to the outer peripheral surface of the body portion of the workpiece,
The printing method according to claim 19, wherein a plurality of objects to be processed carried on the mandrels are continuously conveyed by the conveyance unit. A plurality of the transfer stations are provided on the circulation path of the transfer member, and each of the plurality of ink images formed on the surface of the transfer member at each transfer station is transferred to the outer peripheral surface of the body portion of the workpiece. The printing method according to claim 19 or 20, characterized in that: The mandrel moved along the transport path by the transport unit is rotated in advance by a pre-rotation means and then transported to the transfer station. Printing method. The printing method according to any one of claims 19 to 22, wherein ink ejection not used for forming the ink image is performed on the surface of the transfer member at a predetermined timing. 24. The printing method according to claim 23, wherein ink ejection not used for forming the ink image is performed on a region where the ink image to be transferred is not formed. 25. The printing method according to claim 23, wherein an area where an ink image to be transferred is formed protrudes from the surface of the transfer member as compared with other areas. Performing ink ejection not used for forming the ink image on a region where the ink image is formed;
26. The printing method according to claim 25, wherein the cylindrical object to be processed carried on the mandrel is retracted to a position where it does not contact the transfer member at the transfer station. Performing ink ejection not used for forming the ink image on a region where the ink image is formed;
26. The printing method according to claim 25, wherein an object to be processed to which ink ejection not used for forming the ink image is transferred is excluded downstream of the transfer station. Forming an identifiable pattern by ink ejection not used for forming the ink image,
28. The printing method according to claim 27, wherein the workpiece to which the pattern has been transferred is detected and removed downstream of the transfer station.

Images