JPH0615239B2 - Endless plate splicing method in flexographic printing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for endlessly splicing a flexo sheet plate on a plate cylinder or sleeve in flexographic printing, and more specifically, it is simple and inexpensive, and has extremely high splicing accuracy. The present invention relates to a method of piecing a flexo sheet plate.

Problems to be Solved by the Related Art and Invention Conventionally, as a method of endlessly splicing a flexo sheet plate on a plate cylinder or sleeve in flexographic printing, a flexo sheet plate whose length is a circle of the plate cylinder or sleeve is used. A method has been adopted in which the flexo sheet plate is preliminarily cut on a flat base so as to have the same circumferential length, and then the flexo sheet plate is attached to the plate cylinder or the sleeve peripheral surface using a double-sided adhesive tape or the like. In this case, calculate the cutting length of the flexo sheet plate in consideration of the thickness of the flexo sheet plate and the double-sided adhesive tape, etc., and draw a cutting line with a ballpoint pen or pencil at the cutting point of the flexo sheet plate according to this cutting length. pull,
After that, the flexo sheet plate is cut along this line using a fixed tree and a cutter knife.

However, in the above method, the flexo sheet plate is cut in advance to a predetermined size on a flat base and then attached to the plate cylinder or sleeve, so that the thickness of the flexo sheet plate varies, and the thickness of the double-sided adhesive tape varies. As a result, an error occurs between the calculated flexo sheet plate cutting length and the actually required flexo sheet plate length, and this method has a problem that it is not possible to splic with high precision. Further, the flexo sheet plate is an elastic body, and since the cut portion expands and contracts at the time of cutting, it is difficult to cut the sheet plate linearly, and the plate cylinder or sleeve has a cylindrical shape, and thus the sheet to be attached to this There is a difference between the inner peripheral length and the outer peripheral length of the plate depending on the thickness of the sheet plate, but when cutting the sheet plate on a flat table in advance, it is difficult to calculate this difference and cut it. The method has a drawback that the plate piecing accuracy is reduced due to such a cause.

Therefore, in the conventional plate splicing method, a gap of about 0.5 mm is usually generated in the spliced portion. Therefore, when flexographic printing is performed using the endless plate manufactured by the conventional method, it corresponds to the spliced portion of the printed matter. Color unevenness that can be visually recognized is generated in a portion where the printing is performed, and it is difficult to perform precise and good endless printing.

On the other hand, as a precise plate-making method in flexographic printing, the Stokes-Memex method applying a laser plate-making method or a photo-plate making method has been developed, and these methods enable precise endless plate-making. There is a problem that a dedicated plate cylinder or sleeve is required, the facility is expensive, and the plate making cost is 2 to 6 times as expensive as the above-mentioned conventional method, resulting in a significant increase in cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method capable of endlessly splicing a flexo sheet plate on a plate cylinder or a sleeve circumferential surface with high splicing accuracy at a low cost.

MEANS FOR SOLVING PROBLEMS AND ACTIONS OF THE SAME That is, in order to achieve the above-mentioned object, the present invention provides a method for endlessly splicing a flexo sheet plate on a plate cylinder or sleeve, in the axial direction of the plate cylinder or sleeve circumferential surface. A pair of positioning spacers having almost the same thickness as the flexo sheet plate are arranged at both ends so as to face each other, and one end of the flexo sheet plate is attached to the plate cylinder or the sleeve peripheral surface between these positioning spacers. Then, an adhesive tape for preventing expansion and contraction of the flexo sheet plate is attached to one end of the flexo sheet plate so as to cover the part to be cut, and then the predetermined position of one positioning spacer and the other positioning spacer. The flexo sheet plate is cut along with the adhesive tape along a straight line that connects the specified part of Then, the flexo sheet plate is wrapped around the plate cylinder or the sleeve peripheral surface and adhered, and one end of the adhered flexo sheet plate is peeled off, and the other end of the flexo sheet plate is adhered to the plate cylinder or the sleeve peripheral surface between the positioning spacers. Then, an adhesive tape for preventing expansion and contraction of the flexo sheet plate is attached to the other end of the flexo sheet plate so as to cover the portion to be cut along the width direction, and then the same position of one positioning spacer is applied. Cut the flexo sheet plate together with the adhesive tape along the straight line connecting the location and the same predetermined location of the other positioning spacer to remove the cut end, and then re-attach one end of the flexo sheet plate and join the plates. It is the one.

That is, in the present invention, by cutting the flexo sheet plate with the plate cylinder or sleeve as the above-mentioned configuration, the flexo sheet plate cutting length and the flexo sheet plate cutting length actually caused by the variation in the thickness of the flexo sheet plate and the double-sided adhesive tape A sheet that prevents the occurrence of an error with the required flexo sheet plate length and that the inner and outer circumference lengths of the sheet plate are exactly the same length when the sheet plate is wound around the plate cylinder or sleeve. Cut the plate,
This enables precise piecing. In addition, when cutting both ends of the sheet plate, adhesive tape is attached to both ends to prevent the cut portion from expanding and contracting, which enables the sheet plate to be cut linearly, and a pair of positioning By using a spacer to cut a sheet plate on a plate cylinder or a sleeve exactly along the same straight line, a precise plate piecing is surely performed.

Next, the present invention will be described in more detail with reference to the drawings.

In the present invention, first, as shown in FIG. 1, a pair of positioning spacers 2a having substantially the same thickness as the flexo sheet plate are provided at both axial end portions of the peripheral surface of the plate cylinder or sleeve.
2b are arranged and both of these positioning spacers 2
In order to detachably attach one end 3a of the flexo sheet plate 3 to the peripheral surface of the plate cylinder or sleeve 1 between a and 2b, and to prevent the sheet plate from expanding and contracting along the width direction on the surface of the sheet plate one end 3a. The adhesive tape 4 is attached so as to cover the portion to be cut.

In this case, the shape of the positioning spacer is not limited, but a flexible square plate body with graduations or the like can be preferably used. The positioning spacers 2a and 2b and one end of the sheet plate can be attached to the surface of the plate cylinder or the sleeve 1 by using an adhesive or the like. Also, adhesive tape 4
As the adhesive tape, an adhesive tape made of a polyester film can be preferably used.

In the present invention, next, the predetermined position A of the one positioning spacer 2a and the predetermined position B of the other positioning spacer 2b.
After the sheet plate one end 3a is cut along with the adhesive tape 4 along a straight line C connecting with and, the cut end is removed.

In this case, as a method of cutting the sheet plate 3, as shown in FIG. 2, the side end surface of the cutting tree 5 is arranged along the straight line C, and the cutter knife 6 is provided along the side surface of the tree 5. A method of cutting the sheet plate 3 along the normal direction by using is suitably adopted.

Next, in the present invention, as shown in FIG. 3, the sheet plate 3 is wrapped around the plate cylinder or sleeve 1 and is attached using an adhesive or the like, and the sheet plate one end portion 3a is peeled off and the same as above. The other end 3b of the flexo sheet plate is releasably attached to the peripheral surface of the plate cylinder or sleeve 1 between the positioning spacers 2a and 2b, and the other end 3b of the sheet plate is further attached.
Stick the adhesive tape 4 on. Then, the other end portion 3b of the sheet plate is cut together with the adhesive tape 4 along a straight line C that connects the same location A of the one positioning spacer 2a and the same location B of the other positioning spacer 2b, and a cut end portion. To remove. As the method for cutting the other end 3b of the sheet plate, the above-described method using the fixed wood 5 and the cutter knife 6 as shown in FIG. 3 is preferably adopted. afterwards,
As shown in FIG. 4, one end 3a of the sheet plate is re-attached to the peripheral surface of the plate cylinder or sleeve 1 to join the plates, and both positioning spacers 2a and 2b and the adhesive tape 4 are removed. Precise endless plate piecing is achieved.

EFFECTS OF THE INVENTION As described above, according to the endless plate joining method in flexographic printing according to the present invention, endless plate joining with extremely high joining accuracy can be performed easily and at low cost. Therefore, when flexographic printing is performed on the endless plate manufactured by using the method of the present invention, it is possible to determine with the naked eye of the joint portion that occurs when flexographic printing is performed on the endless plate manufactured by the conventional method. It is possible to achieve extremely precise and excellent endless printing without causing color unevenness.

[Brief description of drawings]

1 to 3 are schematic views for explaining the procedure for carrying out the method of the present invention. FIG. 1 is a perspective view, FIGS. 2 and 3 are side views, and FIG. 4 is the present invention. FIG. 3 is a side view showing an endless plate manufactured by using the method. 1 ... Plate cylinder or sleeve, 2a, 2b ... Positioning spacer, 3 ... Flexo sheet plate, 3a ... Sheet plate one end part, 3b ... Sheet plate other end part, 4 ... Adhesive tape.

Claims (1)

[Claims] 1. A method of endlessly splicing a flexo sheet plate on a plate cylinder or sleeve, wherein a pair of positioning spacers having substantially the same thickness as the flexo sheet plate are provided at both axial ends of the plate cylinder or sleeve. The flexo sheet plates are arranged so as to face each other, and one end portion of the flexo sheet plate is attached to the peripheral surface of the plate cylinder or the sleeve between these positioning spacers. After sticking the adhesive tape for preventing expansion and contraction over the place to be cut, attach one end of the flexo sheet plate along the straight line connecting the prescribed position of one positioning spacer and the prescribed position of the other positioning spacer And the cutting edge to remove, then wrap the flexo sheet plate around the plate cylinder or sleeve circumference. The flexo sheet plate is attached and the one end of the flexo sheet plate is peeled off, and the other end of the flexo sheet plate is attached to the peripheral surface of the plate cylinder or sleeve between the positioning spacers. Affix the adhesive tape to prevent the expansion and contraction of the flexo sheet plate along the place where it should be cut, and then along the straight line connecting the same predetermined position of one positioning spacer and the same predetermined position of the other positioning spacer. An endless plate joining method in flexographic printing, characterized in that a flexo sheet plate is cut together with an adhesive tape to remove a cut end, and then one end of the flexo sheet plate is re-attached for plate joining.