JPH036444Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in printing blankets, particularly for small offset printing presses.

Printing blankets usually consist of a smooth surface rubber layer (ink transfer layer) and a body made of several layers of rubberized cloth bonded together, and this is wrapped tightly around a cylinder to print. conduct.

For example, in a lithographic printing blanket, printing ink is applied to a roll-shaped printing plate expressing characters or figures mounted on a plate cylinder, and the above is applied to the smooth rubber surface of the blanket, which rotates in close contact with the plate cylinder. The characters and images are transferred, and then the characters and images on the blanket are transferred and printed onto a sheet of paper that is inserted between the blanket and an impression cylinder in contact with it.

This blanket is used for newspaper rotary printing and lithographic (offset) printing.
It is widely used because it can produce clear printed matter at high speed.

However, the above-mentioned blankets repeatedly undergo intense compression and recovery during use, and are also slightly abraded, so the surface rubber layer, which is the life of the blanket, is prone to cracking and a decrease in strength.Also, the surface rubber layer, which is the life of the blanket, is prone to cracking and decrease in strength. Deterioration of the rubber layer also occurs,
This blanket therefore needs to be replaced frequently. However, the fatigue of the blanket generally occurs in the surface layer of the blanket, and the inner layer often suffers less damage. However, it has the disadvantage that replacing the entire blanket due to damage to the surface layer is extremely uneconomical and expensive.

The gist of the present invention is to releasably adhere only the ink transfer layer on the surface of the blanket, and to replace only the ink transfer layer if fatigue occurs. By doing so, the blanket can be recycled at low cost and easily, and clear printed matter can be obtained.

The blanket used in this invention is a non-compressible type.
There is no problem with either compression type. In non-compression type blankets, the base material is usually a laminate of several layers of rubberized woven fabric coated with rubber glue of natural or synthetic rubber, while in compression type blankets, the woven fabric laminate described above is used. A foamed layer is included in a part of the base material to improve compressibility.

The woven fabrics used for the base material include natural fibers like cotton, recycled fibers like rayon, polyester,
Woven fabrics made of synthetic fibers such as polyamide and poval, inorganic fibers such as glass fibers and carbon fibers, or hybrids of these fibers (blending, interweaving, etc.) are used. In addition, to adhere these woven fabrics, a flexible material having rubber elasticity, such as natural rubber, synthetic rubber, or polyurethane, is used, and is usually applied in the form of a rubber glue.

Further, in the case of a compression type blanket, the foam layer to be interposed may be a foamed rubber, foamed polyurethane, a rubber sheet uniformly mixed with microballoons, a felt-like nonwoven fabric impregnated with rubber latex, or the like.

The overall thickness of the base material varies depending on the type of printing machine and the type of printed matter, but is approximately 0.5 mm to 2.5 mm, and the thickness of the woven fabric, the number of laminated sheets, etc.
Determine the thickness of the foam layer, etc.

The ink transfer layer on the blanket surface is usually formed of a thin film of an elastic material, such as natural rubber or synthetic rubber. A smooth surface coating layer of several microns thick made of synthetic resin (e.g. urethane) is formed on the surface, but in order to adhere this thin film, a sheet of film, nonwoven fabric, etc. coated on both sides with a releasable adhesive is used. It is preferable to first apply the ink transfer layer to the substrate surface and then apply the ink transfer layer thin film. Of course, in this case, after applying a releasable adhesive to one side of the sheet and attaching it to the substrate surface, a releasable adhesive is further applied on top of that and the ink transfer layer thin film is further attached on top of it. Alternatively, an ink transfer layer may be applied.

By doing so, there is an advantage that when the ink transfer layer thin film on the surface is peeled off, the sheet can be peeled off together with the thin film, making it easier to peel off. Therefore,
As the releasable adhesive between the base material and the sheet, it is preferable to use an adhesive having lower adhesive strength than the adhesive between the thin film and the sheet. Conversely, the adhesive between the base material and the sheet does not necessarily have to be a releasable adhesive.

As the above-mentioned releasable adhesive, a pressure-sensitive adhesive is usually used, but other adhesives that can be peeled off by humidification or heating may also be used. Film, non-woven fabric, paper, etc. are used for the above-mentioned sheet, but non-woven fabric and synthetic paper are preferable because the adhesive easily peels off when the sheet is peeled off, and post-processing such as washing is simplified. be.

Since the printing blanket of the present invention has the above-described structure, when the blanket surface becomes fatigued, only the ink transfer layer on the surface needs to be replaced, and this replacement can be done extremely easily and quickly. Furthermore, since printing is performed reliably, there is an advantage that printing costs can be reduced. In particular, with the recent development of printing machines, printing speeds have become faster and faster, and the effect on the blanket has become more severe. Therefore, the ink transfer layer of the blanket can be replaced easily and inexpensively, and it is now possible to consistently produce clear printed matter. Being able to do so is great news in the printing world.

The invention will now be explained in more detail with reference to the examples of the drawings.

FIG. 1 is a cross-sectional view showing an example of the non-compressible blanket of the present invention, and the blanket 1 is made up of several layers of woven fabric 2 coated with rubber glue 3 made of chloroprene rubber, which are laminated and bonded together. . Further, an NBR ink transfer layer 5 is removably provided on the surface of the blanket base material 1 via a releasable adhesive layer 4. Therefore, if desired, the ink transfer layer 5 can be peeled off from the location of the releasable adhesive layer 4 and a new ink transfer layer 5 can be bonded again.

FIG. 2 is a sectional view showing an example of the compression type blanket of the present invention, in which the blanket base material 1 is
As in the case of Figure 1, neoprene rubber 3 is attached to the woven fabric 2.
Several layers of the foam layer 6 and the foamed layer 6 are laminated and bonded together. In this case, since the foam layer 6 is included, the compressibility is good and a clearer printed matter can be obtained. An ink transfer layer 5 is removably provided on the surface of the blanket base material 1 via a releasable adhesive layer 4, as in the case of FIG.

FIG. 3 is an enlarged sectional view showing an example of the releasable adhesive layer 4 shown in FIG. 1 or 2, in which releasable adhesive layers 8 and 8' are provided on both sides of the film 7. There is. FIG. 4 also shows the peelable adhesive layer 4.
It is an enlarged cross-sectional view showing another example, and is a nonwoven fabric 9.
A releasable adhesive layer 8, 8' is provided on both sides. In both the cases of FIGS. 3 and 4, the ink transfer layer 5
The adhesive force of the adhesive layer 8' in contact with the substrate 1 is lower than that of the adhesive layer 8 in contact with the base material 1, and when it is peeled off, the adhesive layer 8' peels off from the surface of the adhesive layer 8', resulting in ink transfer. Since the layer 5 is peeled off together with the film 7 or the nonwoven fabric 9, the ink transfer layer 5 is less likely to be torn or torn midway, and can be peeled off cleanly and easily.

In addition, it is better to use the nonwoven fabric 9 as shown in FIG.
The bonding with the adhesive is stronger than that of the film 7, and since the adhesive layer 8' is also peeled off cleanly together with the nonwoven fabric during peeling, post-processing such as cleaning is simplified and is advantageous.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a non-compressible blanket of the present invention, FIG. 2 is a cross-sectional view of another example of a compressible blanket of the present invention, and FIG. 3 is an example of a peelable adhesive layer. The enlarged cross-sectional view, Fig. 4, shows
It is an enlarged sectional view showing another example of a peelable adhesive layer similarly. 1... Base material, 2... Woven fabric, 3... Elastic resin, 4
... Peelable adhesive layer, 5 ... Ink transfer layer, 6 ...
Foam layer, 7...Film, 8, 8'...Peelable adhesive layer, 9...Nonwoven fabric.

Claims (1)

[Claims for Utility Model Registration] 1. An ink transfer layer is releasably adhered to the surface of a blanket base material via a releasable adhesive layer, and
The releasable adhesive layer is composed of adhesive layers provided on both sides of a sheet, and at least the layer in contact with the surface of the base material is composed of a releasable adhesive. Printable blanket. 2. The printing blanket according to claim 1, wherein the sheet is made of nonwoven fabric or synthetic paper.