JPS622989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for preprinting cylindrical bodies such as cans in a continuous printing machine.

For continuous printing of cylinders, an apparatus such as that shown in FIG. 1 is generally used. In this figure, an inker unit 1 includes an ink source 2, a duct roll 3 in contact with the duct roll 3 which receives ink, a form roller 5 in contact with an intermediate roller 4 consisting of a plurality of rollers connected thereto, and a printing plate 6 in contact with the duct roll 3. Become. Generally, a plurality of inker units 1 are arranged. On the other hand, a plurality of blankets 7 in contact with the printing plate 6 are attached to the cylindrical surface of the cylinder 8. Furthermore, a can holder 11 to which cans 10 are continuously supplied from a can chute 9 is provided, and the cans 10 rotatably held by the holder 11 are configured to come into contact with the blanket 7.

In this apparatus, when printing on cans, the inker unit 1 transfers printing ink from the ink source 2 via the printing plate 6 onto the blanket 7 on the rotating cylinder 8 as an image, and this image is placed on the can holder 11. A so-called offset printing method is carried out in which the held cans 10 are continuously printed while rotating in contact with each other.

The inker unit 1 is adjusted so as to supply the optimum amount of ink when the cans 10 are being printed continuously. 6. The optimal amount of ink in the blanket 7 and can 10 decreases as the distance from the ink source 2 increases. If the supply of cans is stopped during operation of the printing press, the holder 11 automatically separates from the cylinder 8 and printing is interrupted, but each roller of the inker unit 1 and the blanket 7
The rotation continues as it is, and ink is supplied excessively to the inker unit 1 and the blanket 7, so a mechanism (not shown) is provided to prevent this.
The ductile roller 3 and the foam roller 5 are automatically separated from the ink source 2 and the printing plate 6, respectively.

However, the amount of ink on each of the rollers 3, 4, and 5, which are in contact with each other while being separated, is averaged out as the rollers rotate. As a result, the amount of ink on the form roller 5, printing plate 6 and blanket 7 becomes larger than during normal continuous operation, and the amount of ink on the can 1 increases.
When 0 printing is resumed, the first few dozen cans will be defective because of excess ink.

In addition to the case where the supply of cans stops, during continuous printing, dust, ink scum, etc. adhere to the printing plate 6 or blanket 7, and if these marks appear on the image, it will result in printing defects. It is necessary to stop the supply, stop the printing machine, and remove dust, etc. on the printing plate 6 or blanket 7. Even if only the dust is removed, traces of it will remain on the image, so after wiping off all the ink on the printing plate 6 or blanket 7, it is necessary to adjust the amount of ink to a new optimum level.

Plate 6 or blanket 7 that has run out of ink
In order to supply the appropriate amount of ink without printing on the can, it is best to rotate the form roller 5, printing plate 6, and blanket 7 in contact with each other and supply ink until the appropriate amount is reached. The number of rotations required for printing varies greatly depending on the type of ink, image area, and image shape, so when using multiple inker units with the same mechanism, it is necessary to use the same number of rotations to ensure that the appropriate amount of ink is applied to the blanket 7. It is impossible to do so, and even if printing is restarted under these conditions, several dozen cans will still have excess ink.
Or the ink may be mixed with insufficient ink, resulting in printing defects.

Conventionally, in continuous printing of cans, there is a method for applying an appropriate amount of ink to the blanket 7 when printing is resumed.
The occurrence of poorly printed cans was unavoidable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to prevent continuous printing of cans in a continuous printing device from being interrupted and before the continuous printing of cans is resumed, regardless of whether the ink supplied to the blanket from the inker unit is excessive or insufficient. A pre-printing method that prevents the occurrence of defective cans by printing on a sheet of paper or the like and then restarting continuous printing on the can until the amount of ink supplied to the can becomes appropriate. The purpose of this company is to provide a testing device.

Next, the present invention will be described by way of examples with reference to the drawings. FIG. 2 is a side view of a preprinting device for carrying out the method of the present invention, and in this figure, the continuous printing device and its attached cylinders 8 and blankets 7 are the same as those described in FIG. 1 above. It is. The preprinting device 20 includes a belt-shaped sheet material 21 made of paper or the like, a pressing roll 22 configured to be able to press the sheet material 21 against the blanket 7, a delivery reel 23 for feeding out the sheet material 21, and a sheet material 2.
1, a take-up reel 24 and a pressing roll 22
a roll support member 25 that rotatably supports the roll support member 25; a stand device 27 on which the roll support member 25 is movably mounted via a slide base 26; It has a moving cylinder 28 configured to move. The material of the sheet material 21 is not necessarily paper, but any printable sheet material may be used.

The case where the method of the present invention is implemented using the above-mentioned apparatus 20 will be explained with reference to FIGS. 1 and 2.

Using ink supplied from an ink source 2 to a printing plate 6 by an inker unit 1, an image is continuously printed on a can 10 placed on a blanket 7 and fed from a chute 9. At this time, the pressing roll 22 is separated from the blanket 7 by the moving cylinder 28, and therefore the sheet material 21 is also separated from the blanket 7. If the supply of the can 10 is interrupted now, the ink source 2 and the duct roll 3 will be separated from each other, and the form roller 5 and the printing plate 6 will be separated as described above, but when the supply of the can 10 becomes possible next, the inker unit 1 The supply of ink to the blanket 7 is started. Before the supply of the can 10 is restarted, the cylinder 28 is operated and the sheet material 21 is pressed against the blanket 7 by the pressing roll 22. The sheet material 21 overcomes the braking force of a brake (not shown) built into the delivery reel 23 and is delivered at the same speed as the blanket 7 rotates. As the pressing roll 22 rotates, an image is placed on the sheet material 21 from the blanket 7, and the sheet material 21 is wound onto a take-up reel 24 driven by an air motor or the like (not shown). Then, until the amount of ink supplied to the blanket 7 becomes a normal amount, that is, the amount of ink supplied to the can 10
After printing on the sheet material 21, that is, pre-printing is repeated until it can be normally printed (equivalent to printing on several dozen cans), the sheet material 21 is moved by the moving cylinder of the pressing roll 22. As a result, the can is separated from the blanket 7, and printing on the can is resumed at the same time, and the can 10 is printed normally. At this time, the brake force of the delivery reel 23 is transferred to the take-up reel 2.
If the winding force is slightly stronger than 4, sheet material 2
1 stops feeding, and the sheet material 21 becomes in a standby state. The time for pressing the sheet material 21 against the blanket 7 and the time for restarting printing of the cans 10 are timed by a controller (not shown) of the printing press. Although the above embodiments have been described in the case of printing on cans, the present invention is applicable not only to cans but also to printing on the outer surface of cylindrical articles in general. FIG. 3 shows another embodiment of the device of the present invention, in which the sheet material 21 supported by the pressing roller 22, the delivery reel 23, and the take-up reel 24 is formed into an endless shape, and the surface of the sheet material 21 is A wiping roll 30 is pressed, and the printed image placed on the sheet material 21 is erased by this roll 30. Alternatively, it is not limited to this wiping roll, and any means capable of cleaning the sheet material 21 may be used. Because of this, the sheet material 21 can be used any number of times.

As explained above, by using the method and apparatus of the present invention, it is possible to completely eliminate the conventional practice of producing several dozen poorly printed cans when restarting continuous printing of cans after interruption. Ta. Furthermore, the apparatus for carrying out the method of the present invention is simple in structure, low in cost, and can be easily installed in conventional continuous printing apparatus without any modification.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view for explaining a can continuous printing apparatus, FIG. 2 is a side view of an embodiment of the present invention, and FIG. 3 is a partial side view of another embodiment of the present invention. 7... Blanket, 8... Cylinder, 10...
...Can, 20... Preprinting device, 21...
... Sheet material, 22 ... Pressing roll, 23 ......
Delivery reel, 24... Take-up reel, 25...
Support member, 26...Slide base, 27...Base device, 28...Movement cylinder, 30...Wiping roll.

Claims (1)

[Scope of Claims] 1. A continuous printing method in which an inker unit places an image on a blanket mounted on a cylinder, and prints the image onto a cylinder that is continuously supplied while rotating each other, the cylinder After the supply is interrupted and before restarting, a sheet material that can be printed is pressed against the blanket and the printing is performed until normal printing is possible on the sheet material, and the amount of ink on the blanket becomes normal. A preprinting method characterized in that the sheet material is removed from the blanket after the printing is done, and at the same time printing of the cylinder is resumed. 2 A sheet material attached to a continuous printing device having an inker unit, a blanket attached to the outer peripheral surface of the cylinder, and means for supplying a cylindrical body so as to be printed in contact with the blanket, and capable of coming into contact with and separating from the blanket; A pressing roll configured to be able to press a sheet material onto the blanket, a delivery reel for feeding out the sheet material, and a take-up reel for winding up the sheet material, on the blanket after printing of the cylindrical body is interrupted and before restarting. 1. A pre-printing device, characterized in that the printing image is printed on the sheet material until normal printing becomes possible, and then normal continuous printing of the cylindrical body becomes possible. 3. The preprinting apparatus according to claim 2, wherein the sheet material is formed into an endless shape and a wiping means that contacts the sheet material is attached.