JPH0230299Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a blanket deformation prevention sheet used for the impression cylinder of a lithographic printing machine.

In conventional lithographic printing machines, a rubber blanket is attached to the blanket cylinder as shown in Figure 4, and the ink transferred from the plate cylinder passes between the blanket cylinder and the metal impression cylinder. Printing is performed on paper, but if the surface to be printed on is uneven, such as an envelope, repeated printing will cause unevenness on the surface of the blanket, which will cause uneven ink transfer and dark and light prints. There was a drawback that it could be done.

The purpose of the present invention is to eliminate such drawbacks of lithographic printing machines and to provide a blanket deformation prevention sheet that can be accurately and reliably adhered to the surface of an impression cylinder. A fabric with a soft synthetic resin layer formed on one or both sides is used, and a low adhesive layer is placed on the soft synthetic resin layer on one side of this elastic base material, and a high adhesive layer is placed on the fabric or soft synthetic resin layer on the other side. The high-adhesion layer and the low-adhesion layer are each attached with a release paper, and its structure will be described in more detail with reference to an example shown in FIG.
is an elastic base material, in which a soft synthetic resin layer 2, for example a polyethylene resin layer, is formed on one side of a fabric 1. 3 is a synthetic resin-based low adhesive layer coated on the soft synthetic resin layer 2, and its adhesive strength is such that it can be temporarily fixed to the blanket described later, for example, 100 g/
It is about 25mm wide. 4 is a rubber-based high adhesive layer applied to one side of fabric 1, and its adhesive strength is 930g/
It is 25mm wide. 5 and 6 are low and high adhesive layers 3 and 4
A release paper is attached to each. In addition, numeral 7 is a blanket cylinder of the lithographic printing machine, 8 is a rubber blanket stuck to the blanket cylinder 7, 9 is an impression cylinder with the same diameter as the blanket cylinder, 1
0 is a plate cylinder with the same diameter as blanket cylinder 7, 11 is ink, 12
is an ink roller, 13 is an envelope, 14 is a paper feed tray, 1
5 is a paper feeding device, 16 is a chain delivery, and 17 is a paper discharge tray.

Incidentally, as shown in FIG. 2, an elastic base material a in which soft synthetic resin layers 2, 2 are formed on the front and back sides of a fabric 1 may be used.

Since one embodiment of the present invention has the above-mentioned configuration, the release paper 4 of the low-adhesive layer 3 is peeled off, the low-adhesive layer 3 is pasted on the blanket 8 attached to the rubber cylinder 7, and then the high-adhesive Remove the release paper 6 of layer 4 and remove the rubber cylinder 7.
When the impression cylinder 9 is rotated at a constant speed, the high adhesion layer 4 adheres to the impression cylinder 9 and the low adhesion layer 3 is peeled off from the blanket 8. Therefore, the blanket deformation prevention sheet
As shown in the figure, it is affixed to a predetermined position on the rubber cylinder 7. In this adhered state, the low adhesive layer 3 on the surface disappears during the printing process several times, and the soft synthetic resin layer 2 of the elastic base material a is exposed.

As described above, the blanket deformation prevention sheet used for the impression cylinder of the lithographic printing machine according to the present invention has a low adhesive layer on one side of the elastic base material, which is the soft synthetic resin layer, and the other side, which is the fabric or soft synthetic resin layer. A high-adhesive layer is formed on the layer, and the low-adhesive layer is used to temporarily fix it to the blanket of the rubber cylinder, and the high-adhesive layer allows it to be transferred to the impression cylinder. It can be easily and accurately attached to a predetermined position on an impression cylinder that is difficult to attach. In particular, this deformation prevention sheet has a fabric interposed in the core, so it does not stretch in the front, back, left or right due to the pressing force during printing, and as shown in Figure 5, the elastic base material and high adhesive layer are It absorbs irregularities on the printing surface such as envelopes and prevents deformation of the blanket, so even if you print repeatedly, there will be no uneven transfer of ink to the blanket, so you can repeatedly print without unevenness. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing one embodiment of the blanket deformation prevention sheet according to the present invention, Fig. 2 is a longitudinal sectional view showing another embodiment, and Fig. 3 is a longitudinal sectional view showing the use of the blanket deformation prevention sheet according to the present invention. FIG. 4 is a schematic diagram of a lithographic printing press according to the present invention; FIGS. 4 and 2 are explanatory diagrams showing the relationship between a blanket and an envelope when the blanket deformation sheet according to the present invention is not used; FIG. 5 is a schematic diagram of a blanket according to the present invention. An explanatory diagram showing the relationship between a blanket and an envelope when a deformation prevention sheet is used. a...Elastic base material, 1...Fabric, 2...Soft synthetic resin layer, 3...Low adhesive layer, 4...High adhesive layer, 5,
6...Release paper.

Claims (1)

[Scope of utility model registration request] In an elastic base material formed by forming a soft synthetic resin layer on one or both sides of a fabric, a low adhesive layer is placed on the soft synthetic resin layer on one side, and a high adhesive layer is placed on the fabric or soft synthetic resin layer on the other side. A blanket deformation prevention sheet for use in an impression cylinder of a lithographic printing machine, which is formed by forming layers and attaching release paper to each of the high and low adhesion layers.