DE86790C - - Google Patents

Description

IMPERIAL

PATENT OFFICE

PATENT DOCUMENT.

CLASS 15: Printing.

Patented in the German Empire on July 4, 1894.

The invention

relates to a method for making hatch or dot style executed vacuum plates, for example for negative printing of labels, Letterheads and the like, as well as for the production of end papers and the like, in which this means different shades of the negative pressure are caused, that the printing Areas of the lines or points are partially enlarged.

For this purpose, a layer is first produced which has raised, sharpened or pointed reproduction lines or points of uniform height and consists of a material which is sufficiently hard or rigid to be able to be ground down or cut out field by field. This work is usually carried out by hand using suitable knives or engraving tools, but can also be carried out by machine using milling cutters, e.g. B. in Guilloche chemistry. The deeper the deepening of the layer surface is carried out, the deeper the later impression of the relevant points will be made, since the width of the individual lines increases towards the depth (cf. the cross-section of layer H in FIG. 2). The material of the printing surface prepared in this way must be sufficiently flexible. be malleable, so that those surface fields of the same, which the cut respectively. The cut-out parts correspond to the cut-out parts and are, as a result, sunk against the normal printing plane, can be lifted into the plane of the parts of normal or original height, so that by this lifting the whole surface of the printing layer can be brought to the same type height. This work is carried out in such a way that the back of the layer is glued to a base of suitable plastic material and then pressed into this mass in such a way that the unevenness of the pressure surface is on the back of the layer. can be transferred while the entire printing surface is brought into one plane. The plastic mass of the layer that forms the bed is then allowed to harden or solidify, whereupon the printing surface is ready for use in the press.

Celluloid is preferably used as the material for the layer, which after it is covered on both sides with cotton cloth, between those moistened with camphor alcohol Blotting paper is softened. The cotton stuff prevents the blotting paper to which the celluloid adheres. Thereon the blotting paper is removed and the tissue is peeled off from one side of the celluloid plate. The side of the celluloid plate exposed in this way is applied to one containing the hatching or puncture Die placed and after placing a rubber sheet or the like. In the 'previously oiled Impressed shape.

With a correspondingly simple basic pattern, the shape can consist of a corrugated plate or a fine sieve of the appropriate mesh size, or as specially prepared Relief surface are formed, which consists of conical webs or spike-shaped projections, the apex of which BEZW. sharpen turned outwards and through deeper ones

Claims (1)

Interstices are separated into which the softened celluloid is pressed. After the layer of celluloid or other malleable material has been molded has experienced and is hardened in the form, it is taken out of this and now the preparatory work described at the beginning of sanding, cutting or sinking in places subject to the printing area according to certain patterns, drawings, etc. A device used for leveling the pressure surface is shown in FIG. 1 in a top view, in FIG. 2 in section along the line xx . A is a wooden board on which plastic mass B is applied, which is evenly distributed on the board in an expansion corresponding to the size of the layer to be produced. This mass is enclosed on all sides by four wooden strips C , which are surrounded by a rectangular steel frame D with a space E left. Springs are arranged between the bars C and frame D , which keep the bars pressed against the enclosed mass. The mass B is then coated on top with a layer of glue and the rear, flat side of the layer H is placed on this, after this side has been covered with a layer of fabric which increases the adhesion. The now uneven pressure surface of the layer is now covered with a thin zinc plate / and over it a pref roller J is guided back and forth with pressure until it runs on the correspondingly high cheek strips of the steel frame D. The springs F yield enough so that the mass B can expand into space E according to the amount of the pressure exerted by deflecting the strips C. Now the zinc plate is removed and the base is allowed to harden. The wooden plate A, the mass B and the layer H together have exactly the type height, so that the printing plate obtained can be used in the printing press. If a pattern is to be printed in different colors, there will be just as many Printing areas applied when different colors are to be printed. Through several to the Combined effects can be achieved by printing surfaces prepared one above the other. The new procedure gives, among other things, the possibility of strongly contrasting Shadow or Establish light boundaries by making an incision in the layer makes and the layer material on one side of the slot up close to the same deepens up. The faintest shadow appears immediately in such places when printing occur next to the deepest, since the abraded part of the surface is in one plane is brought with the immediately adjacent, not processed part. Patent claim: Process for the production of vacuum plates with shaded hatching, grain size and the like, consisting in the fact that a corrugated or grained plate of celluloid and the like. the shade to be achieved is worked out in depth, whereupon the printing surface by pressing under a flat plate into a base made of plastic, which later hardens Material is pressed in so far that the printing surface parts are all in one plane reach. For this purpose ι sheet of drawings.