JPH02229046A - Printing blanket cylinder and its usage - Google Patents

Abstract

PURPOSE:To offer an inexpensive blanket readily interchangeable with a clean blanket whenever a plate is replaced and to eliminate cleaning of a blanket cylinder incorporated into the blanket surface, that is, a printing press. CONSTITUTION:A multi-layered blanket is used for the cleaning-free printing blanket cylinder. A 1st layer 12 is formed with a sheet made of polyester, etc., serves as a solid supporter supporting a 2nd layer 14, and preferably has a uniform layer thickness. The 2nd layer 14 is an elastic body that looks like natural rubber, etc., composed of single rubber or mixture, and preferably has a uniform layer thickness. To mount a blanket 8, the end of a blanket roll 4 is inserted into a blanket gripper 2, and the blanket 8 is wound around the blanket cylinder 10 while the cylinder is rotated, and a required amount of the blanket 8 is cut by a cutter 6. Upon the completion of printing, the blanket 8 whose surface is spoiled by ink is scraped away, and disposed of, instead of cleaning the blanket 8.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention eliminates the need for cleaning the blanket by making the blanket in offset printing disposable for one pattern. This invention relates to a blanket cylinder for offset printing.

(Prior Art) Conventionally, blankets used in offset printing are expensive and are not replaced every time a pattern or plate is replaced. Typically, a blanket receives ink from the plate and does not transfer all of this ink to the substrate, leaving the remaining ink transferred to the substrate on the blanket. Furthermore, even if the ink supply is stopped and printing is continued, a small amount of ink will remain on the blanket. If these inks are used to print different patterns, defects such as stains and color unevenness will appear on the printed matter. Therefore, in order to obtain a clean printed matter, a clean blanket surface is required, so the blanket surface, that is, the blanket 1 to the cylinder on which the blanket is attached, is washed with washing oil or the like.

(Problems to be Solved by the Invention) In view of the above problems, an inexpensive blanket that can be replaced with a clean plankkent every time the plate is replaced is provided, and the blanket surface, that is, the blanket cylinder incorporated in the printing machine, is cleaned. The purpose is to make it unnecessary.

(Means for solving the problem) The method will be explained below using drawings. In order to achieve this objective, the cleaning-free printing blanket cylinder of the present invention uses a blanket having a multilayer structure as shown in FIG. The first layer 12 is formed using a sheet of polyester, polycarbonate, vinyl chloride, etc., paper, aluminum, etc., and the second layer I4
It is a hard support that supports. The first layer 12 preferably has a uniform thickness. In addition, it is preferable to use a material that has close contact with the plumket cylinder, and a material that exhibits electrostatic adhesion is preferable.

The second layer 13 is made of a rubber-like elastic material such as natural rubber, NBR rubber, nitrile rubber, urethane rubber, silicone rubber, acrylic rubber, etc., alone or in a mixture thereof, and has a J thickness of 10 μm to 500 μm.

The second layer 14 preferably has a uniform thickness, with a tolerance of 5
It is desirable that the thickness be within 0 μm.

FIG. 2 shows an explanatory diagram of how plankens 1 to 4 stored in a roll are rewound and attached to the Offsera I/plunket body 10. First, place the end of the blanket 71 □ roll 4 between the plank wafer 2 and the blanket 1lli.
Wrap the blanket 8 while rotating 110.

After that, the required amount of plankent 8 is cut out using cutter 6. Next, when printing is completed, by peeling off the blanket 8 whose surface is stained with ink, the planken 1-8 can be used disposable without cleaning.

(Function) As described above, it is possible to move on to printing the next pattern without performing a blanket cleaning operation in offset printing.

(Example) Hereinafter, an example will be described using the drawings. The blanket used for the cleaning-free printing blanket 1lliil is the first one.
In the figure, Planken 1 has a multilayer structure, and the first layer 12 is a polyester film having a thickness of 50 μm to 500 μm, preferably 100 μm, and the thickness tolerance is within 10 μm. If the thickness is less than 50 μm, the blanket lacks rigidity and wrinkles occur, making it difficult to attach to the blanket body. Thickness is 50011m
If it is thicker, it will be too rigid and difficult to attach to the blanket body. Moreover, if it is thick, the price of the blanket will increase, which is not preferable. It is also preferable to coat or laminate one side of the polyester film with polyethylene, polypropylene, etc. to improve its adhesion to the blanket cylinder. The second layer 14 is made by applying a coating liquid consisting of 10 parts of natural rubber, 12 parts of a solvent, a coloring material, a vulcanizing material, etc. to the first layer 14 using a wire bar.
After coating the back surface coated with polypropylene or the like of layer 12 and drying, the coating was wound up into a roll. The second layer 14 had a thickness of 100 μm, and the total thickness of the first layer 12 and second layer 14 was 200 μm.

In FIG. 2, the Planken [8] stored in a roll 4 in the blanket cylinder 10 is rewound and put on the blanket body 10.

First, the end of the blanket roll 4 is held in the blanket gripper 2, and the planken 1-8 is wound around it while rotating the blanket cylinder 10. After that, the plankent 8 is cut out in the required amount using a cutter 6. Planken: The surface of the hemlock 10 is made of a smooth metal surface. Alternatively, the surface has an underblanket structure made of cork, single foam sponge, etc., and the surface is a smooth surface to which the coating surface of the first layer, such as polyethylene, can easily adhere.

As an underblanket structure, from the part in contact with the Planken body, a shoelace made of 200 mm thick Gyanhas fabric, 200 μm thick rubber, 400 μm thick single foam sponge, and 200 μm thick rubber is used. The material was used. When stamps were made using these, it was difficult to set the printing pressure when attached directly to the metal surface, but printing using an underblanket structure with a compressed layer made it easier to set the pressure, resulting in good print quality. was easily obtained. The rigidity resistance of the blanket was about 30 minutes or 4000 impressions, but it can be easily set by changing the second layer rubber material. Next, when printing is completed, the blanket 8 whose surface is stained with ink is peeled off. Next, by attaching a new blanket 8, offset printing was possible without performing a blanket cleaning operation.

(Effects of the Invention) The cleaning-free printing blanket cylinder according to the present invention can use an inexpensive blanket that can be replaced with a clean blanket every time a plate is replaced, and can eliminate the need for cleaning the blanket surface. There were almost no printing defects caused by scratches or stains on the blanket surface. Depending on the settings such as the rubber material on the surface of the blanket, the printing durability of the master paper plate for transfer paper can be obtained, and the rigidity of the plate can be appropriately matched, making it possible to stop during printing to replace the blanket. Nor. Since cleaning the blanket surface is no longer necessary, printing work becomes more efficient, work becomes safer by eliminating the use of organic solvents, and safety is also increased from a disaster prevention perspective.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a blanket used in a cleaning-free printing blanket cylinder, and FIG. 2 is an explanatory view showing how the blanket is attached to a cleaning-free printing blanket cylinder. 2 Blanket grip 4 Blanket roll 6 Cutter 8 Blanket 10 Blanket body 12 -th layer 14 Second layer

Claims (3)

[Claims] (1) A blanket cylinder for offset printing, comprising a blanket cylinder and a blanket roll installed near the blanket cylinder, and a sheet-like blanket wound around the blanket roll is attached to the blanket cylinder. (2) The blanket cylinder for offset printing according to claim (1), wherein the sheet-like blanket is composed of a support and a rubber-like elastic body. (3) Consisting of a blanket cylinder and a blanket roll installed near it, the sheet-shaped blanket wrapped around the blanket roll is printed for each pattern to be printed.
A method of using a blanket cylinder for offset printing, characterized in that it is attached to the blanket cylinder.