DE2500612A1 - Gravure printing plates - Google Patents

Description

PATENT LAWYERS r η η CM

MÖLLER-BORS CRGENING DEUFEL 2 5 0 UD \

MUNICH 35 · οΙΕΒΞλΤβίΒ. i TEL. '.

- 9 JAN. 1975

D / Sh - E 1162

ENCOLINE (PROGRESS) LIMITED Slough, Bucks.
Great Britain

Gravure plates

The invention relates to gravure plates of the type in which the image to be printed is engraved into a surface of the plate and the ink, sealant or other material to be printed into the engraved image through the Thickness of the plate is supplied by means of through holes.

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ORfGlNAL fNSPECTED

In the type of device to which such plates can be applied and which are, for example, the subject of the application the same applicant on the same day with the internal AZ E 1161; Title: Process and device for printing or deposition of material on a base that forms, are injection units between the engraved printing plate, also called an embossing lath or die can be referred to, and one of the two cooperating pressure plates arranged so that when moving towards each other the press plates the deposition of the material to be printed is effected by causing the injection units to pump the material into the wells in the plate.

It has been found that when the material to be printed has a hard, unyielding nature or deviates from a flat central surface within the area to be printed insist, it is difficult to keep the substance to be printed within the required limits, resulting in lack of definition of pressure.

For example, if the plate is used to print sealing material and / or adhesive onto a gasket, it is the case that the surface of the seal is irregular, especially in the area which has a bore surrounds, which can be covered or covered with a metal ring or band that protrudes over the surface of the seal ^ A method to account for both surface irregularities and changes in compressibility, is therefore required.

Another problem arises with printing non-compressible ones Metal surfaces with a certain degree of roughness. If the embossing batten isn't compressible either, it is difficult to achieve clean edges on the printed material.

These problems are essentially overcome by a gravure printing plate of the type described according to the invention, in which little

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at least part of the engraved printing surface from a thin one Layer of compliant material is formed. This surface can then be the irregularities in the surface to be printed take up.

The entire printing surface can be covered with, for example, rubber, Plastic or some other material that is insensitive against attack by the material to be printed and which is sufficiently elastic to allow the material to be printed within a sharp outline on the print base. Alternatively, the elastic material can be used as an insert or inserts only on selected parts of the surface of the embossing batten are present.

Preferably the entire surface of the base plate is made of, for example a "Tufnol" (see Römpp, Chemielexikon, 6th edition) or similar material covered with a thin layer of an elastic material that is vulcanized and then into that the desired image is engraved. Preferably, the image is only engraved into the thickness of the elastic coating, but can can also be cut into the base plate.

It has been found that a layer of synthetic rubber with a minimum thickness of about 0.5 mm (20/1000 ") is preferred, however the thickness can be up to approx. 1 mm (40/1000 "), the thickness depending on the condition of the surface to be printed.

It can be seen that the area of the engraved image is reduced becomes / when pressure is applied to print because of the compliance of the surface coating. So must the engraved Image should be a little larger in area than the desired print.

The invention is described in more detail below under Reference to the accompanying drawing.

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_ 4 Fig. 1 is a schematic view of a gravure printing device,

Fig. 2 is a sectional view of part of an example of a printing plate according to the invention, and Figs

Fig. 3 is a view similar to Fig. 2 but modified Shows the shape of an embossing bar.

In Fig. 1, a printing plate or embossing plate 10 for printing a pattern is held by an upper support plate 11, which on an upper press plate 12 is seated. The press plate 12 cooperates with a lower press plate 14 'on which the to be printed Foil is put on. In the following, the material to be printed on is described as a sheet of paper, but expressly it should be noted that the invention is applicable to any material to be printed with a pattern, regardless of whether it is in the form of a film or consists of paper. As an addition. game it can be a seal to be printed with a sealing compound.

In the device of Fig. 1, dye, a sealant or another printing fluid to be printed is through the Pressure plate 10 is injected by a plurality of injection units 15, three such units in the drawing for Imprints of three different colors are shown. The injection unit shown is particularly suitable for printing Color spots on a color card, as they are intended to display the respective colors of specific dyes or paints. Each injection unit supplies pressurized fluid to a gravure depression in the face of the plate.

The injection units 14 are each supplied by a corresponding reservoir 15 for pressure fluid. Each injection unit 14 is connected to the corresponding reservoir 15 by a flexible line 16, which pressure fluid from the reservoir to Inlet of the injector leads. While the reservoir 15 is under pressure

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can stand, the supply from reservoir 15 is preferably one Gravity feed.

The injection units may comprise a piston which works as a pump so that when the plates 12 and 14 'printing material in the injector is pressed against and through the embossing bar or pressure plate 10.

In Fig. 2, the printing plate 10, which is made of a synthetic resin-bonded Board 17 consists, with a thin layer 18 of elastic Material covered (the layer is shown to be much thicker in relation to the plate than would be the case in practice). An image indicated at 20 is engraved in the elastic material and communicates with holes 22 which pass through the Thickness of the plate go, and which in use the material to be printed is fed from the injection units 15 will. The image 20 is only cut into the elastic layer 18 and does not go through the layer into the board.

When the plate is used for printing on uneven surfaces, the surface irregularities or the deviations become compensated in the compressibility of the material to be printed by the flexibility of the layer 18.

The plate shown in Fig. 3 differs from that of Fig. In that the engraved image or recess 20 is through the elastic layer 18 is cut into the board 17.

It can be seen that the two channels 22 shown are connected to the recess stay in contact. More or fewer channels (and injectors) can be used, depending on the size and shape of the recessed image. Likewise, if the plate has more than 1 recessed image, the other recesses can be replaced by additional Injectors are fed, and these can if desired can be used to print different print materials through each recess.

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Claims (5)

Claims { 1. Gravure printing plate of the type in which the image to be printed is engraved in one surface of the plate and the material to be printed, such as printing ink, sealant or other material, is fed into the engraved image through the thickness of the plate by means of holes made through go the plate, characterized in that at least part of the engraved printing surface is formed from a thin top layer of elastic material. 2. Plate according to claim 1, characterized in that · net that the whole printing surface is covered with a layer of the elastic material is covered. 3. Plate according to claim 1, characterized in that that the elastic layer acts as an insert or inserts on selected parts of the engraved printing surface is present. 4. Plate according to one of the preceding claims, characterized in that the image to be printed is only engraved in the thickness of the elastic layer. 5. Plate according to one of the preceding claims, characterized in that the layer of the elastic Material has a thickness of approximately 0.5 to 1 mm (20/1000 "- 40/1000"). 509828/0698 Blank page