US2138703A - Method of printing - Google Patents

Description

NOV. 29, 1938. w MATUSCHKE v2,138,703

METHOD OF PRINTING Filed Oct. 12, 1936 fir/7e d Fe/ferd H mm 541M770 m\\\\\l\ Mk v Z p f ATTORNEYS Patented Nov. 29, 1938 UNITED STATES PATENT OFFICE April 11, 1935 10 Claims. (Cl. 101-211) This invention relates to a method of printing with a typographic press, 1. e., one wherein the printing is done directly on the paper from elements having their printing surfaces in relief, and involves the use of printing inks which are solutions and/or dispersions of organic dyestuil's or mineral dyestuils in volatile solvents and relates also to improved relievo printing elements for carrying out such method.

Heretofore, dyestufl's of the character referred to, have been employed with rubber printing elements in the production ofcolored paper for wrapping purposes, paper bags, etc., and although ior this purpose its use has been extensive. it has been quite definitely limited to this field. Inks of this character present many advantages over the usual varnish inks used in letter press work because of the simple construction and operation of the inking apparatus required, and also because of the quick drying properties of the inks as a result of which smudging of the freshly printed sheets is substantially avoided. Because of the many advantages inherent in such inks, it has been proposed to use them in high speed rotary presses for newspaper and illustration work, where heretofore varnish inks have been exclusively employed.

In the production of colored paper,'wherein the use of solutions or dispersions of organic dyestuifs or mineral dyestufis in volatile solvents is common, rubber printing elements have been employed as previously stated, the reason being the particular afinity which solutions of this character have for the rubber surface. In adapting high speed rotary presses for use with such inks in the printing oi? newspapers, illustration worlr, and the like, the some practice has been followed, that is, rubber printing elements havebeen used, the general practice being to use a metal printing element for the black varnish inks and arubber printing element for the color work, the rubber printing elements being used mostly in combinatlon with boolr printing presses, as auxiliary printing mechanisms. Metal printing elements,

such as stereotypes and electrotypes have been avoided with solutions and dispersions oi organic and mineral dyestuffs, because these solutions, being substantially of the consistency of water, are repelled by the metal surfaces, the solutions being deposited thereon in fine disconnected globules instead of in thin uniform coatings necessary for good printing, whereas in the instance of etched surfaces, it has been found that the solutions flow down into the etched recesses, filling them up and destroying the tones of the printed reproductions.

It has been found however, that there are many disadvantages inherent in the rubber printing elements when used for newspaper or illustration 5 work, since when even the slightest pressure is used, the screen points or the lines of a line drawing or of aletter character yield or are otherwise deformed. To overcome this difliculty, it has been proposed to reinforce the rubber printing forms with insertions of textile fabrics, wire woven fabrics, or the like, or by vulcanizing very thin rubber forms on metal plates, but even with such expedients, the necessary rigidity in the relief portions can not be attained, or at the most, only to a very small degree. Another disadvantage in the rubber printing elements 101' rotary presses is that the elements can only be made flat and in mounting on the cylinder must be bent to suit the diameter of the cylinder, with the result that distortion in the face of the element is unavoidable.

Still another disadvantage in the use of rubber printing elements resides in the difficulty and expense of manufacture. Special equipment, such as vulcanizing presses and other accessories are necessary, as well as a special technique which can be acquired only after considerable experience in the work. For these and other reasons, the use. of rubber printing elements in book printing plants has been found uneconomical. In newspaper printing, there is the further disadvantage that where it is desired to print, say a red he s t line, it has been found very difiicult to prepare the rubber printing forms with the necessary speed, even when rubber is used.

Contrary to the procedure that has been here toiore followed, it is proposed, in accordance with the present invention, to use with inlis consisting of solutions and/or dispersions of organic dye- 4o stuffs or mineral dyestufis in volatile solvents, such as methanol, ethyl alcohol and acetone or water, with or without the addition of suitable binding agents, the ordinary plates of stereotype metal, electrotypes or etched lined or screened plates. lll necessary, the stereotypes and electrotypcs should be degreased before use with suitable solvents, such as alcohol, and particularly in the case of large or unbroken surfaces, should be smoothly polished with polishing media, as for instance, polishing rubber, so as to insure that the inks will be properly taken up and given 0d. Proper polishing of the plates will obviate the tendency of the ink to be depositedin globules.

In the case of etched plates, the etching must be at rapidly vulcanizing 35 somewhat deeper, say approximately one and one-half times that normally used with varnish inks. The deeper etched plates will allow the ink to run down into the etched cavities without filling them up and destroying the tones. Extensive experiments made by the inventor have proved that when printing with inks, which are solutions and/or dispersions of organic dyestuffs or mineral dyestufis 'in volatile solvents, 10. from printing elements of stereotype metal or from electrotypes or etched plates, it is possible to obtain an inking equal to that of rubber printing plates, while the accuracy of the impression is considerably greater than with the known rubber 15 printing elements. It is assumed, of course, that suitable stereotype plates or electrotype plates are used, in which the surface hasa very high degree of smoothness and freedom from pores. The concentration of the inks must, when printing 20 letter press and line drawings, be greater than when printing large or unbroken surfaces.

One of the advantages of the invention, as com pared with the use of rubber printing elements, resides in the fact that printing elements made 25 of stereo metal and the electrotypes are superior in durability, and consequently will have longer life. The screen points and the lines of an etched plate also have the same qualities. For best re- ,uits however, the printing pressures should be 30 r latively light and evenly applied. The appli- 1 c tion of the ink to the printing-element is; also simplified, in that it is necessary only to have a single applying roller in'contact with the printing element and which transfers the ink direct- 35 1y from-the immersed roller which dips intothe ink box, but here again the pressure of the inking roller on the printing element should be comparatively light and evenly applied for the best results. Also, the distortion in the face of the 40 printing element from bending on the printing cylinder in rotary machines, is avoided, since the metal elements are preshaped tofit the cylinders.

A further advantageof the invention is that the existing stereotype or electrotype arrange- 5 ments in printing plants can be used without any alteration for the production of, the printing forms, except for the polishing operation which, as previously stated, may be necessary to enable the inks which consist of the organic or mineral 50 dyestuffs dissolved or dispersed in 'volatile solutions to be picked up by the printing elements. Finally, stereotype plates for rotary newspaper presses can be made in a considerably shorter time than the corresponding rubber printing ele- 55 ments, so that it is possible to produce actual prints, such as head lines, when using inks of this character in the limited time required for such work.

Referring to the drawings:

60 Fig. 1 is a diagrammatic view of a rotary typographic press suitable for the practice of the in-. vention; and

Figs. 2, 3 and 4 show, respectively, partial sectional views of an etchedrelievo plate, an elec- 5 trotype plate and a stereotype plate, and which may be used in the press in practicing the invention.

As shown in Fig. 1, a paper web A is fed between an impression cylinder 13 and a printing 70 cylinder C, the latter bearing the printing plates from which the impression is transferred to the paper web. The printing cylinder, as usual,v is inked by means of an applying roller D rotating with the same peripheral speed as the printing 75 cylinder and arranged for light tangential contact therewith. The ink is contained in a trough E of the usual character from which the ink is picked up by a fountain roller F, arranged to rotate therein. In a typographic press utilizing ordinary varnish inks, there is a train of rollers 5 between the fountain roller and the applying roller in direct contact with the prlnting'cylinder in order that the ink, which is of a heavy or thick consistency, can be rolled down for application in a thin film to the printing cylinder. In accordance with the present invention, however, the applying roller D in contact with the printing cylinder C also contacts directly with the fountain roller F, this being possible because of the fact that. the printing ink used in practicing 15 the present invention is substantially of the consistency of water, and consequently does not require the rolling down and thinning out action that is required when varnish inks are used.

The method of the invention can be practiced by the use of any suitable metal'typographic surface. Thus, by way of example in Fig. 2, there is illustrated an etched screened relievo copper plate G which is virtually the same as the ordinary copper half-tone except that the etching is somewhat deeper, so that the highly fluid ink can run down into the etched recesses without filling them up to the .level of the type high printing surface. It will be readily seen that if the etched recesses were filled up completely, the effect of the dot configuration would be lost with a consequent deleterious effect in the rendering of the tones by the plate. An etched copper or nine line plate can also be used in carrying out the method. 1 The electrotype plate (see Fig. 3) is the same as that ordinarily used and consists of an electroplated shell H carrying the printing impression fastened to a backing element J which renders the printing surface type high. The only step 40 necessary to make the ordinary electrotype plate suitable for use with the inks herein dealt with is that of rendering the printing surface capable of picking up the highly iiuid ink in a thin film of uniform thickness'over the entire printing surface. This can be done by degreasing the plate before use and by polishing the printing surface to the extent necessary to produce the desired result.

The stereotype plate K shown in Fig. 4 is likewise of the usual character and is prepared for use in the instant process by degreasing and polishing the surface, as in the case of the electrotype plate.

While the plates herein illustrated have been shown flat, it will be understood that when they are used in a rotary press, they will be made in conformance with the usual practice followed in adapting such plates to a cylindrical printing form.

With regard to the inks herein dealt with, it might be stated that they are exceptionally well adapted for printing, say a colored border on the white margin of a newspaper, as a result of the fact that the ink dries immediately. When varnish inks are used, they do not dry in the requisitely short time, so that printing on a white margin with varnish colors is impossible, owing tothe smudging which would occur.

By far, one of the greatest advantages flowing from the use of the inks herein dealt with is in their application to multi-color printing. These inks being transparent, will permit those printed first to show through those subsequently printed, so that true color combinations are reproduced,

mechanical manufacture called "wrong covering" due to the covering power of the separate varnish one above the other. Errors may also occur in the individual color separation negatives obtained by three color photography. Finally, there may be errors in screening. All these sources of error could not be observed and avoided independently in the separate prints heretofore, but could only be removed by lengthy correction during the etching of the plates. As a result, the manufacture of etched plates for three color printing required a long time, for example, ten to fifteen days.

When transparent inks are employed however, the error resulting from wrong covering is obviated as a result of the character of the ink, while the 'other'errors can be observed independently and the corrections made prior to the final etching process, with the result that the photoof etched plates of correct color values can be carried out in a small fraction of the time heretofore required, for example, in a few hours.

In manufacturing screened plates for three color photography,- the three color separation negatives are obtained in the usual way and printed on ordinary white non-transparent photographic paper. Thereafter, visible prints in black and white are obtained from'the three color separation negatives and can be reduced or enlarged to the size desired for the etched plates. These visible prints make it possible for the operator to observe whether thecolor distribution is correct in the three separation negatives or'whether alterations have to be made. If B1?- terations are required, they can be made in a simple manner by raising or lowering the color values on the visible prints, thus eliminating the re-touching in the final plate for removing individual colors and varying tones, a step which is now necessary in the manufacture of ordinary multi-color plates. From these three positives or negatives, three screen negatives are made which can be made denser or lighter, as required by varying the illumination. In this way, the screening errors are eliminated. The screen negatives arethen printed in the usual way on the metal plates, for example, zinc or copper plates, having a light sensitive colloid layer, and the printed plates then etched without covering and immediately proved. The covering of the etched plates and the use of mechanical tools generally em-- ployed for voiding the covering errors is thus avoided. The plates are etched somewhat deeper than usual for the reasons hereinbefore set forth In addition to the saving in time, there is a further advantage, namely, in that only three colors are required for printing the usual run of work and that a better graduation of the half tones is obtained, so that the individual color grades come out more pleasingly. Obviously, more colors can be used for obtaining particular color values.

In the foregoing specification, the method of the invention has been described merely by way of example, and obviously many variations and modifications may be made therein which will still be comprised within the spirit of the invengraphic web press, three color photography. The first is. the soinks which are printed tion. It is to be understood, therefore, that the invention is not limited, except insofar as such limitations are specified in the appended claims.

Having thus described my invention, hat I claim is:

1. The art of printing with a rotary typowherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web, characterized in this that the printing element is metal and that the ink is a water-thin, quickdrying solution of dyestuff such as heretofore has been used in a rotary typographic web press only with rubber printing elements.

2. The art of printing with a rotary typographic web press, wherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web, characterized in this that the printing element is metal with'an etched printing surface and that the ink is a water-thin, quick-drying solution of dyestuif such as heretofore has been used in a rotary typographic web press only with rubber printing elements.

3. The art of printing with a rotary typo graphic web press, wherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web characterlzed in this that the printing element is metal with an etched screened printing surface and that the ink is a water-thin, quick-drying solution of dyestuff such as heretofore'has been used in a rotary typographic web press only with rubber printing elements.

4. The art of printing with a rotary typoaphic web press, wherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web, characterized in this that the printing element is metal with a screened printing surface etched substantially greater than necessary when varnish inks are used and that the ink is a water" thin, quick-drying solution of dyestuffs such as heretofore has been used in a rotary typographic web press only with rubber printing elements.

5. The art of printing with a rotary typo graphic web press, wherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web, characterized in this that the printing element is metal with a screened printing surface etched approximately one and one-half times greater than necessary when varnish inks are used and that the ink is a water-thin, quick-drying solu. tion of'dyestuff such as heretofore has been used in a rotary typographic Web press only with ruhber printing elements.

6. The art of printing subjects having variations both as to color and tone, with a rr a r-y typographic web press wherein the relief surfaces of the printing element are coated with different colored ink which is superposed one color over the other directly on the paper web, c acterized in this that the printing elements are metal and have their printing surfaces etched variably depending upon the gradations of the graphic web press,

thin, quick-drying solution of dyestufl such as heretofore has been used in a rotary typographic web. press only with rubber printing elements.

8.The art of printing with a. rotary typowherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web, characterized in this that the printing element is a metal stereotype with its printing surface highly polished, and that the ink is a waterthin, quick-drying solution of dyestuffs such as heretofore has been used in a rotary typographic web press only with rubber printing elements.

9. The art of printing 'with a rotary "typographic web press, wherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web,

Patent No. 2,158,705.

WALTER HATUSCHKE.

characterized in this that the printing element is an electrotype and that the ink is a waterthin, quick-drying solution of dyestufl such as heretofore has been used in a rotary typographic web press only with rubber printing elements.

10-. The art of printing with a rotary typographic web press, wherein the relief surfaces of the printing element are coated with an ink which is transferred directly to the paper web, ,characterized in this that the printing element is metal and free from grease and that the ink is a water-thin, quick-drying solution of a dyestufl such as heretofore has been used in a rotary typographic web press only with rubber printing elements.

' WALTER MATUSCI-IKE.

CERTIFICATE OF CORRECTION.

I November 29, 1958.

I It is hereby certified that error appears lnthe printed specification of the above numbered patent re'c uiring correction as follows: Page 5-,

"dyestuffs" read dye stuff; page LL, first column,

column, line 55, claim h, for 6', for "element" read elements;

second line 61, claim line 11, claim 8 for the word" "dyestuffs" read dyestuff;' and that the said Letters Patent should be "read with this correction thereinthat'the same may conform to the record of the case in the Patent Office.

Signed'and sealed this 10th day of January, A. D. 1959.

v 4 (Seal) Henry Van Arsdalo J t v Acting Commissioner of Patents

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