JP2018008386A - Blanket for offset printing and offset printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blanket even having a blank part formed in a rubber layer for forming and printing a second design, having no penetration of a solvent component into interlayer between the rubber layer and a substrate layer, or the substrate layer and an adhesive layer during coating or washing, hardly generating deterioration of the rubber layer around the blank part and hardly generating displacement of fitting position to a blanket wheel, and an offset printing device using the same.SOLUTION: There are provided a blanket for offset printing 110 having a rubber layer 111 with a printing surface on an outside surface and a substrate layer 113 on an inner surface side of the rubber layer 111, where the rubber layer 111 has a concave blank part 112 on the outside surface and covers the substrate layer 113 from an outside surface side without gap, and an offset printing device 100 using the same.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blanket for offset printing and an offset printing apparatus, and more particularly to a blanket for offset printing and an offset printing apparatus provided with an engraved blanket.

Conventionally, as a printing method for printing objects such as labels for cans and PET bottles, dry offset is provided by using a resin relief plate on each color inker plate cylinder, transferring each color ink from the resin relief plate to the blanket, and transferring printing from the blanket to the printing object. Many methods are used. It is known that an adhesive blanket is used as a blanket for reasons such as screen dimension stability and blanket exchangeability. The blanket is generally composed of a smooth rubber layer that forms the printing surface, an adhesive layer for attaching to a predetermined position of a printing machine, and a base material layer sandwiched between the rubber layer and the adhesive layer. Is.
However, in recent years, the development of dry offset printing technology that forms and prints a second design by engraving a part of a blanket and making a blank part that does not carry ink in offset printing of a two-piece can has advanced. It has been.

  For example, a printing apparatus for a can known from Patent Document 1 includes a blanket wheel on which a blanket can be mounted at predetermined intervals, a plurality of plate cylinders arranged around the blanket wheel, and a plate on a blanket mounted on the blanket wheel. It has an inker that supplies ink through a cylinder, and a mandrel wheel that transfers cans from a conveyor and makes rolling contact with the blanket on the blanket wheel. The ink supplied from the inker is transferred to the blanket by the plate cylinder. The blanket and the can are in rolling contact with each other, and printing is performed on the cylindrical surface of the can.

  In addition, each blanket is not a mere smooth surface as in a normal transfer blanket, but has a shallow relief (low relief, shallow recess) blank portion as a location where ink is not supplied from the plate cylinder. This makes it possible to obtain pallets (multiple cans) with different blanks or imprint arrangements for each blanket at the end of the can production line, with a design that is partially different on the cylindrical surface of the can Can be continuously manufactured from the same printing apparatus.

JP-T-2015-526317

In the blanket of the printing apparatus of Patent Literature 1, the depth of the shallow relief blank portion is formed to a depth of 0.38 mm or more. At this time, when a thin blanket having a rubber layer thickness of 0.38 mm or less is used, the blank portion penetrates the rubber layer, and the base material layer is exposed on the printing surface side. As a result, the paint component during printing and the solvent component during washing penetrate into the interlayer between the rubber layer and the base material layer, the base material layer, and the adhesive layer. There has been a problem that deterioration and a decrease in the adhesive ability of the adhesive layer easily progress.
In addition, the stress applied to the rubber layer is concentrated around the blank portion penetrating the rubber layer, and there is a possibility that problems such as tearing of the rubber layer or loss of part of the rubber layer may occur.
In addition, when the blank part that penetrates the rubber layer continues to both ends of the blanket, when the blanket is attached to the blanket wheel, the blanket part that penetrates the rubber layer is easily deformed around the blanket and the blanket attachment position may be shifted. was there.

  The present invention solves these problems, and even if it is a blanket in which a blank portion is formed on a rubber layer for forming and printing a second design, the solvent component at the time of coating or cleaning is rubber. Blanket for offset printing that does not penetrate between the layer and the base material layer, the base material layer, the adhesive layer, etc., the rubber layer around the blank part is not easily deteriorated, and the mounting position on the blanket wheel is difficult to shift. Is intended to provide.

The blanket for offset printing of the present invention is a blanket for offset printing having a rubber layer having a printing surface on the outer surface and a base material layer on the inner surface side of the rubber layer, and the rubber layer is A concave blank portion is provided on the outer surface, and the base material layer is covered without a gap from the outer surface side.
The offset printing apparatus of the present invention includes the offset printing blanket.

According to the blanket for offset printing and the offset printing apparatus of the present invention, even if the rubber layer has a concave blank portion on the outer surface, the rubber layer covers the base material layer without gaps, The solvent contained in the paint or cleaning agent applied to the rubber layer does not penetrate between the rubber layer and the base material layer, or between the rubber layer and the base material layer due to the solvent or the base material layer. Can be prevented.
Further, since the rubber layer does not have a blank portion having a depth reaching the base material layer, local stress concentration such as tearing or chipping of the rubber layer can be suppressed.
Furthermore, since the rubber layer does not have a blank portion having a depth reaching the base material layer, and the printing surface is continuously formed without a break, the shape of the printing surface is hardly distorted and the mounting position of the blanket is difficult to shift.

The perspective view and sectional drawing of the blanket 110 for offset printing concerning one Embodiment of this invention. 1 is an overall schematic diagram of an offset printing apparatus 100 according to an embodiment of the present invention. FIG. 3 is an enlarged view of the vicinity of a contact portion between a blanket wheel 120 and a plate cylinder 124 of an offset printing apparatus 100 according to an embodiment of the present invention. Sectional drawing and the top view which show the state of the blanket 110 before and after transferring the ink P to the blanket 110 for offset printing which concerns on one Embodiment of this invention, and the printing plate 125. FIG. The schematic diagram which shows the process of transferring the ink P mounted on the blanket 110 for offset printing which concerns on one Embodiment of this invention to the can C.

Hereinafter, a blanket 110 for offset printing and an offset printing apparatus 100 according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a blanket 110 for offset printing according to an embodiment of the present invention includes a rubber layer 111 having a printing surface on the outer surface, and a base material layer 113 on the inner surface side of the rubber layer 111. doing.
The rubber layer 111 is made of, for example, acrylonitrile butadiene rubber (NBR).
The base material layer 113 preferably has a two-layer structure of a base fabric layer and a sponge layer so that the plate pressure during printing is suitable. The base fabric layer and the sponge layer both transmit liquids such as printing ink and cleaning solvent. The base fabric layer is formed of, for example, a woven fabric formed by including resin fibers such as nylon fibers or polyester fibers, or a cotton fabric. The sponge layer is formed of a foamed material such as rubber (for example, chloroprene rubber, acrylonitrile butadiene rubber (NBR), hydrogenated acrylonitrile butadiene rubber (HNBR), etc.) or a synthetic resin (for example, polyurethane).
On the side opposite to the rubber layer 111 side (inner surface side) of the base material layer 113, a known polyester urethane type, epoxy type adhesive, rubber type, acrylic type, epoxy type or vinyl ether type synthetic resin is used as a base. In the present embodiment, a layered adhesive layer 114 is provided as an adhesive.

The rubber layer 111 has a concave blank portion 112 on a part of the smooth outer surface side.
However, the blank portion 112 does not have a portion penetrating to the back surface of the rubber layer 111, and covers the base material layer 113 from the outer surface side without a gap.
The depth of the blank portion 112 is shallower than the thickness of the rubber layer 111 and is not formed so as to penetrate the rubber layer 111.
The blank portion 112 is formed so as to leave at least 0.03 mm or more of the rubber layer 111.
The offset printing apparatus 100 according to an embodiment of the present invention includes a blanket wheel 120 as shown in FIGS.
A plurality of mounting bases 121 (only one is shown in FIG. 2 for simplicity) are provided on the side surface of the cylindrical blanket wheel 120 so that the blanket 110 can be mounted with an adhesive. It is configured to be possible.

A plate cylinder 124 and a mandrel wheel 130 that rotate in synchronization with the blanket wheel 120 are provided around the blanket wheel 120.
A printing plate 125 is attached to the side surface of the cylindrical plate cylinder 124. A plurality of inker rollers 123 of the inker 122 are provided around the plate cylinder 124.
The mandrel wheel 130 is provided with a mandrel 131 that can enter and exit the can C, enter, support from the opposite side of the can bottom Cb formation side (see FIG. 5), and can rotate.
A varnish coating unit 140 and a transfer turret 141 are adjacent to the mandrel wheel 130.

Next, a printing procedure on the can C by the offset printing apparatus 100 using the blanket 110 according to an embodiment of the present invention will be described with reference to FIGS.
First, the can C supplied to the offset printing apparatus 100 is rotatably held by the mandrel 131 with the mandrel 131 entering and the cylindrical surface exposed, and is conveyed to the blanket wheel 120 side by the rotation of the mandrel wheel 130. .
The printing plate 125 attached to the side surface of the cylindrical plate cylinder 124 is brought into rolling contact with the inker roller 123 of the inker 122 by the rotation of the plate cylinder 124, so that the ink P adhering to the adjacent inker roller 123 is removed. It is supplied to the convex portion 126 on the surface of the printing plate 125.
At this time, since the color of the ink P that can be supplied from one inker 122 is one color, when printing with a plurality of colors, the ink is applied to the printing plate 125 by using the same number of inkers 122 as the number of colors of the ink P to be used. P will be supplied.

The printing plate 125 supplied with the ink P moves toward the blanket wheel 120 by the rotation of the plate cylinder 124, and makes rolling contact with the blanket 110 that has moved toward the plate cylinder 124 by the rotation of the blanket wheel 120.
At this time, the ink P supplied to the convex portion 126 of the printing plate 125 is transferred to the surface of the rubber layer 111 of the blanket 110, but the blank portion 112 of the blanket 110 does not contact the convex portion 126 of the printing plate 125. The ink P is not transferred to the blank portion 112.

The blanket 110 to which the ink P has been transferred is directed toward the mandrel wheel 130 by the rotation of the blanket wheel 120, contacts the can C that has been directed toward the blanket wheel 120 by the rotation of the mandrel wheel 130, and the ink applied to the blanket 110. P is further transferred to the can C.
At this time, since the can C is rotating while being supported by the mandrel 131 on the side opposite to the can bottom Cb formation side, the cylindrical surface of the can C and the blanket 110 are in rolling contact.
In addition, since the ink P applied to the rubber layer 111 other than the surface on which the blank portion 112 is formed is transferred to the cylindrical surface of the can C, depending on the shape of the blank portion 112 to which the ink P is not supplied, in addition to the design of the printing plate 125 A new design (second design, ○ and △ in the figure) is applied, improving design.

In addition, when a plurality of blankets 110 mounted on the blanket wheel 120 have different blank portions 112, the design transferred to the can C is different for each blanket 110. Can be manufactured continuously from the same offset printing apparatus 100.
That is, the number of designs printed on the cylindrical surface of the can C can be easily increased.
The can C to which the ink P has been transferred is brought into rolling contact with the burnish coating unit 140 by the rotation of the mandrel wheel 130 and the mandrel 131, and the cylindrical surface of the can C is surface-treated.
After that, the can C moves from the mandrel wheel 130 to the transfer turret 141, and is further transferred to the pin chain 200 and conveyed to the next process.
In the blanket 110 of the present invention and the offset printing apparatus 100 using the same, since the rubber layer 111 covers the base material layer 113 from the outer surface side without a gap, the base material layer 113 and the adhesive layer 114 are on the outer surface side ( It is not exposed on the print side.
Therefore, the ink P applied to the outer surface of the rubber layer 111, the solvent used when cleaning the outer surface of the rubber layer 111, the interlayer between the rubber layer 111 and the base material layer 113, the base material layer 113 (also the base material layer) 113 between the base fabric layer and the sponge layer) and the adhesive layer 114, it is possible to prevent deterioration of the interlayer, the base material layer 113, and the adhesive layer 114, and to suppress the frequency of replacement due to the deterioration of the blanket 110.
Further, since the blank portion 112 is formed so as to leave at least 0.03 mm or more of the rubber layer 111, the shape of the printing surface is not easily distorted, and the mounting position of the blanket 110 on the blanket wheel 120 (the blanket mounting base 121) is The rubber layer 111 does not become excessively thin, and the rubber layer 111 is not torn or chipped due to a load applied to the blanket wheel 120 or printing.
In addition, since the base material layer 113 has a base cloth layer and a sponge layer that transmit liquid, the flexibility of the base material layer 113 is increased, and the blanket 110 and the printing plate 125 are in rolling contact with each other. In addition, at the time of rolling contact between the blanket 110 and the cylindrical surface of the can C, they can be brought into close contact with each other without a gap.

As mentioned above, although the embodiment of the blanket for offset printing and the offset printing apparatus of the present invention has been described in detail, the present invention is not limited to the above embodiment, and departs from the present invention described in the claims. Various design changes can be made without any change.
In the above-described embodiment, the offset printing apparatus is described as transferring and printing ink from the blanket to the cylindrical surface of the can. However, the printing target is not limited to this, for example, before forming the cylindrical shape. It may be a plate-like metal surface or a surface of a paper product such as cardboard.
In the above-described embodiment, the printed can has been described as passing through the transfer turret and transported to the next process by the pin chain. However, the method of transporting the can is not limited to this, for example, by a conveyor. It may be conveyed.
In the above-described embodiment, the blank portion is described as being formed in a concave shape surrounded by a rubber layer. However, the shape of the blank portion is not limited to this, and the blank portion is formed on the outer peripheral edge of the blanket. It may be adjacent. For example, the blank portion may be formed in a concave groove shape that divides the outer surface of the rubber layer.
In the above-described embodiment, the base material layer has been described as having a two-layer structure of a base fabric layer and a sponge layer. However, the layer structure of the base material layer is not limited to this, and may be a single layer, for example.
In the above-described embodiment, the adhesive is described as having a uniform layer shape. However, the application state of the adhesive is not limited to this, and for example, the adhesive is interspersed by application within a range where the blanket can be bonded and fixed. May be.

DESCRIPTION OF SYMBOLS 100 ... Offset printing apparatus 110 ... Blanket 111 ... Rubber layer 112 ... Blank part 113 ... Base material layer 114 ... Adhesive layer 120 ... Blanket wheel 121 ... Blanket mounting base 122 ... Inker 123 ... Inker roller 124 ... Plate cylinder 125 ... Printing plate 126 ... Convex part 130 ... Mandrel wheel 131 ... Mandrel 140 ... Burnish coating unit 141・ ・ Transfer turret 200 ・ ・ ・ Pin chain C ・ ・ ・ Can Cb ・ ・ ・ Can bottom P ・ ・ ・ Ink

Claims (7)

A blanket for offset printing having a rubber layer having a printing surface on the outer surface, and a base material layer on the inner surface side of the rubber layer,
The blanket for offset printing, wherein the rubber layer has a concave blank portion on an outer surface, and covers the base material layer without a gap from the outer surface side.   The blanket for offset printing according to claim 1, further comprising an adhesive that adheres the blanket to a blanket mounting base on the side opposite to the rubber layer side of the base material layer.   The blanket for offset printing according to claim 1 or 2, wherein the base material layer has a base fabric layer and a sponge layer that each transmit a liquid.   The blanket for offset printing according to any one of claims 1 to 3, wherein a depth of the concave blank portion is shallower than a thickness of the rubber layer.   The blanket for offset printing according to any one of claims 1 to 4, wherein the thickness of the thinnest portion of the rubber layer having the concave blank portion is 0.03 mm or more.   An offset printing apparatus comprising the blanket for offset printing according to any one of claims 1 to 5.   The offset printing apparatus according to claim 6, wherein a plurality of blanket mounting bases for bonding the offset printing blanket to a surface of a blanket wheel of the offset printing apparatus are arranged at a predetermined pitch.

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