US1958299A - Intaglio printing methods and apparatus - Google Patents

Description

May 8, 19340 aEmcKssoN INTAGLIO PRINTING METHOD AND APPARATUS Filed 001;. 15. 1930 Patented May 8, 1934 i UNITED STATES PATENT OFFICE.

INTAGLIO PRINTING METHODS AND APPARATUS Emil Ericksson, Chicago, Ill., assignor to Standard Process Corporation, Chicago, 111., a corporation of Delaware Application October 15, 1930, Serial No. 488,916

6 Claims. (Cl. 101375) The present invention relates to improvekeeping large stocks of expensive copper rolls 1 ments in methods and apparatus for producing on hand for practical intaglio textile wall paper and utilizing forms adapted to be etched for and like printing operations. For color printing, intaglio printing purposes, but useful for other sets of copper cylinders of exactly the same size 3 uses, such, for example, as drying cylinders or with from three to as many as fourteen cylin- 60 cans in textile printing operations, to receive ders in each set must be kept, the number in ornamental etchings, and like purposes. each set depending upon the number of colors More particularly the present invention re in the design. lates to novel methods and apparatus for pro-' Such prior processes require in addition to W viding seamless thin lightweight metallic shells heavy expensive printing press equipment, the as or cylinders preferably of copper, and to novel maintenance of grindin polishing and etching methods of utilizing such shells as printing forms equipment, and employment of expensive labor, for intaglio printing, etching, drying, omamenwith the result that the costs thereof are protation, and like purposes. hibitive except for large establishments. In adle Prior to the present invention there have been dition the cylinders used are of such expensive 70 two general methods of utilizing removable copconstruction that it is impractical to preserve per shells or cylinders for intaglio printing puretchings for reuse for a. great length of time. poses. In the first of these methods a heavy Consequently, if the design has been ground oil, steel cylinder or collar heavily plated with copnew cylinders of exactly the same size must be 20 per is mounted on an extending mandrel of an re-etched. This would in most cases be prac- 7s intaglio printing press. These heavily plated tically an impossibility. cylinders, collars, or rolls, are ground, polished, To overcome the necessity for repeated grindetched, and removably mounted on expanding ing and polishing operations and to secure mainmandrels in intaglio printing presses. After the tenance of uniform diameter of printing surface,

as desired number of impressions have been made thereby eliminating the expensive equipment for from the etched surface, the collar or roll is regrinding and polishing and the costs of varying moved, the etching is laboriously ground away, design sizes with varying cylinder sizes, and to the surface again polished and re-etched with permit exact reproductions of designs to be made a new design to be printed. These grinding, for reuse, the Ballard process was developed for go polishing, etching and printing operations are producing intaglioprinting surfaces by electrorepeated, continually reducing the circumferplating a layer of copper of a thickness suitable ence of the printing cylinder until insuflicient for receiving a single etching on a base roll havcopper remains on the steel cylinder for furing a high y polished surface or barrier layer ther etching. The swel cylinder is then again with which the electro-deposited copper will not heavily electroplated and the foregoing operaintimately unite, so that the copper layer may go tions are repeated. be removed from the base by stripping or de- In the second of prior methods utilizing replating operations without injuring the polished movable shells, solid copper cylinders with a surface of the base. The Ballard processes are wall thickness of approximately one inch are disclosed in Ballard Reissue Patent #17,179 ism pressed on tapered intaglio printing press mane sued January 1, 1929, and in co-pending apcircle by hydraulic pressure, and the surface plication serial No. 270,367 filed April 16, 1928, thereof is rematedly ground, polished, etched, and have met with marked commercial success and the etchings printed in=the manner above and wide recognition in the rotogravure printse forth in connection with use Of the pp ing industry as a substantial improvement over as plated s l cy These Operations r prior processes in large rotogravure and intaglio loo ried out repeatedly until the copper wall is re printing t b m, duced to about one-half its :=..-.1 thicmess, The Ballard processes are, however, also adaptwhen, because of the reduction in diameter it ed especially for large size printing establish= can no longer be re-etched and must be disments, for which they are far superior to the e carded. methods of utilizing heavy copper cylinders Both p or methfids o using removable D- above set forth. The rolls in the Ballard proc per cylinders are expensive and laborious and esses are, however, too expensive to permit keep= necessitam the constant changing oi the sizes ing of etched designs for reprints on a coinof designs to correspond to the reduced size of mercial scale, although as above pointed out so printing rolls. Furthore, they require because of the uniformity in size of successive 1m printing forms utilized, practical re-etching and duplication of given designs has been made possible thereby.

Accordingly no effective process has heretofore been developed that may be installed and operated with an initial investment and at operating costs permitting profitable intaglio printing operations in small printing establishments, or commercially feasible storage of etched forms forsupplying exact duplicates of designs, highly desirable in commercial textile, wall paper, oilcloth and other types of intaglio reproduction work.

As is well known in intaglio printing operations, a doctor blade must be forced against the etched cylindrical surface with a sufiiciently heavy pressure to effectively and thoroughly wipe the ink from the high surfaces of the etch ing. The pressure of the doctor blade must be so great against the printing surface to secure an effective wipe, that even though a comparatively hard metal such as copper is utilized to receive the etchings, the dark-tones of the images etched in the metal must be built up of a series of minute recesses of varying depths separated by minute supporting and strengthening walls of metal. These strengthening walls are commonly produced by utilizing screens to divide the image to be etched into minute areas divided by the supporting walls which resist breaking down of the etched surface under the heavy pressure of the doctor blade. Because of the heavy pressure exerted by the doctor blade and impression cylinder, it has been heretofore deemed that either a heavy wall shell of copper or a layer of copper solidly backed by a metallic base roll must be utilized to provide an effective intaglio printing form.

However, by extensive experimentation, I have discovered that it is possible to effectively and economically produce and etch a very thin copper shell of a uniform thickness sufficient to receive only one etching, which, mounted on a properly constructed supporting mandrel, will withstand the heavy doctor blade and impression cylinder pressure necessary for effective rotogravure printing.

This discovery has made possible marked economies-in intaglio printing operations, and permits the adoption of novel methods of operation, making intaglio printing operations available to establishments insufficient in size to profitably install the prior processes and further, making effective storage and preservation of etched forms commercially feasible. The use of these novel and improved methods of operation are also applicable to larger establishments not utilizing the prior removable copper cylinder types of equipment as for example now used to a large extent in the intaglio wall paper and textile printing industries, with marked economies due to the fact that the improved shells of the present invention are uniform in size and quality and weigh considerably less than the removable copper cylinders of the processes in common use. The uniformity in size considerably reduces the stock of cylinders that must be kept on hand for color work, and eliminates the necessity and expense of changing sizes of designs due to continual change of diameter of cylinders. Their use at the same time eliminates all grinding and polishing operations, and the expensive labor, space and equipment necessary for such operations and eliminates the loss of copper incident thereto. Eurthermore, the investment, labor,

equipment, and cost of handling the heavy cylinders weighing hundreds of pounds each, used in the prior methods of intaglio printing is eliminated by the use of the improved thin cylinders of the present invention which weigh from a few ounces in'the small sizes up to a few pounds for the larger sizes.

This vast saving in weights of cylinders handled in accordance with the present invention effects very important economies in the costs of transportation and at the same time speeds the transportation materially, as the improved cylinders of the present invention may be shipped by parcel post or express at a fraction of the cost of shipment of the heavy copper cylinders of the prior processes and which are of such a size as to necessitate their shipment by freight.

The reduction in costs of shipping and labor of handling and the speeding up of transportation made possible by use of the cylinders of the present invention permits intaglio printing operations in small establishments where the cost of intaglio printing operations of any kind have heretofore been prohibited, by making feasible the economical operation of central plants for the preparation and etching of cylinders. The central plants may be properly equipped to produce the etched and un-etched cylinders in desired sizes, employing the highest grade labor and scientific equipment therefor to produce high grade cylinders at minimum cost. The cylinders prepared as desired by the printing establishments may then be rapidly shipped by express or parcel post, or otherwise conveniently distributed to the printing establishments. This concentration of production of cylinders and etching at properly equipped central plants for the first time made commercial: feasible by the present invention, eliminates the necessity for maintenance of etching, polishing, and grinding equipment and labor at the printing plant, permits the production of etched printing forms at materially reduced cost, and makes commercially profitable intaglio printing possible in small establishments in which an intaglio printing press with a suitable mandrel to properly support the improved thin etched forms of the present invention is the sole equipment. In addition the improved etched forms of the present invention may be readily removed from the mandrel, stored for reuse, and kept at small cost over long periods of time, permitting exact duplication of designs in nature and size without re-etching operations at any time. This convenience of storage and feasibility of commercial reproduction, it will be appreciated, permit of marked economies in textile, wall paper and other printing industries, by permitting smaller quantities of given designs of goods to be ordered made up on initial orders, with absolute assurance that perfectly reproduced and matched designscan be had at low cost and short notice, thereby eliminating necessity for overstocking on a particular design to be certain that enough goods of a given design to meet commercial requirements will be available. This feature will therefore be appreciated to be a new and highly useful result of the present invention not heretofore attainable in the intaglio printing arts.

In addition to being highly useful as printing forms, the-cost of production of the improved cylinders of the present invention by the preferred method hereinafter set forth, is so low as to permit their economical use as copper cans or drying cylinders for printed webs, and their uniformity of size makes them far more desirable for this purpose than the cylinders heretofore used for this purpose which have been heretofore made by the crude process of bending sheet copper into cylindrical form and brazing the edges together. The improved forms of the present invention are also admirably adapted to be etched -and oxidized for ornamental purposes.

Accordingly a primary object of the present invention is to provide novel low cost and improved printing forms for use in intaglio printing purposes that permit adoption of novel methods of operation, and marked economies in operation and equipment.

'Another object of the present invention is to provide novel methods and apparatus that will permit the Widespread'profitable use of intaglio printing in establishments where the cost of equipment and operation of prior intaglio printing methods has heretofore been prohibitive, and will permit the commercial exact reproductions of given designs over an indefinite period of time.

Still another object of the present invention is to provide novelmethods .ofproducing uniform comparatively hard metal cylinders useful as intaglio printing forms, adaptedto receive a single etching only, as drying cylinders, and other uses, at low cost.

A further object of the invention is to provide novel mountings for thin metallic shells of a sufllcient thickness to receive a single etching, providing a support of sufiicient firmness to withstand the heavy doctor blade and impression cylinder pressure for proper intaglio printing operation.

Further objects of the invention will appear from the following detailed disclosure of preferred embodiments thereof and from the scope of the appended claims.

Referring to the drawing:

Figure 1 is a more or less diagrammatic illustration of a preferred method of forming thin polished uniform metallic cylindrical shells forming a part of the present invention.

Figure 2 is a sectional elevation through a preferred embodiment of cylinder mounting showing a cylinder in accordance with the present invention supported in printing position.

Figure 3 is an end view of the form of inven'-. tion shown in Figure 2.

Figure 4 is a sectional view taken along line IV-IV of Figure 2.

Figure 5 is a side view partially in section of a modified form of mounting for cylinders of the present invention.

Figure 6 is an end View of the cylinder mounting shown in Figure 5, with the end cup removed.

As shown in Figure 1, in the preferred method of forming the cylindrical metallic forms utilized in the present invention, a base cylinder or form 1 is provided with a highly polished or mirror finished barrier surface 2 of alloy or other substances of the character disclosed in Ballard Reissue Paten.- 1'7.l79, issued January 1st, 1929..or of nickel applied as disclosed in said co-pending application Serial No. 270,367, and with which electro-deposited copper will not intimately unite.

A uniformly thin layer of copper or similar metal 3 is uniformly electrolytically deposited on polished barrier layer 2 in the manner disclosed in said Reissue Patent No. 17,179 or said application S. N. 270,367, the thickness of the deposited metal being just suflicient to receive a single intaglio etching, and the preferred thickness being approximately from 0.005 of an inch to 0.030 of an inch. The outer surface of the deposited metal will be polished and of texture adapted to receive an etching for intaglio printing purposes, without further polishing. w}; i

The cylinder with the deposited metal is then inserted in a suitable lathe and rotated. A suitable burnishing tool or roller 4 is then pressed against and moved along the rotating electro-deposited surface 3 with a uniform pressure suflicient to slightly and uniformly stretch shell 3 to free the shell from surface -2 of cylinder 1. A burnishing pressure will be found sufficient for this purpose, and in addition to loosening the shell, the burnishing action produces a beneficial polishing and smoothing effect on the surface of shell 3.

For convenience in operation and to insure the maintenance of a uniform pressure along shell 3, the burnishing roller or tool 4 is preferably,rotatably mounted in lever 5 pivoted at 6 on standard 7 of movable tool supporting table 8. Table 8 is slidably mounted on guideways 9 of lathe bed 10, and is moved along the guideways longitudinally of shell 3 by means of a well known feed arrangement (not shown).

Formed on the opposite end of lever 5 is a handle 7 section 11 provided for convenient manipulation,

against the shell of cylinder 3 with a pressure requisite to properly loosen shell 3 from barrier surface 2 of cylinder 1. v

The lathe is driven at such a speed and the weights 13 are so proportioned that when the burnishing roller 4 has traversed the entire length of shell 3 it will be uniformly stretched and loosened from surface 2 of cylinder 1, and shell 3 may then be removed endwise from cylinder 1 in the form of a copper shell or tube of a uniform thickness just sufiicient to receive a single intaglio etching without further preparation.

Shell or tube 3 may be etched either before or after, and preferably after, removal from forming cylinder 1 with any desired design for intaglio printing purposes; and may be shipped before or after etching to a printing establishment. In unetched form shells or tubes 3 are suitable for use as drying shell or copper "cans" used in textile printing industries, and such shells are admirably suited for this purpose because of their uniformity of size and low cost of production.

For intaglio printing purposes the etched shell 3 is mounted by the printer in a press provided with an expansible mandrel giving a firm support and proper backing to the shell in order that it may resist the heavy pressure of the doctor blade and impression cylinder in operation.

A mandrel construction admirably suited for this purpose and arranged for facile application and removal of shells 3 from ,a rotogravure press is disclosed in Figures 2, 3 and 4. This improved mandrel construction comprises a shaft 15 provided with suitable bearing sections 16 adapted for mounting in the bearings of an intaglio printing press in well known manner. As is well known. one end of the shaft 15 is mounted in a removable hearing so that removal and replacement of shells 3 may be effected without disturbing the mounting of the driven end of the mandrel in the press.

Formed integrally on the shaft 15 are the enlarged threaded sections 17 and tapered frustroconical wedging sections 18 as shown clearly in Figure 3. Each section 18 is provided with a plurality of wedge shaped segment expanding and contracting members 19 slidably fitting into complemental recesses 21 formed in the expansible and contractible wedge shaped segments 22 of the mandrel construction.

Wedge shaped segments 22 are shaped to fit slidably together and to form a substantially solid cylindrical support when expanded to firmly grip a shell 3 in the position of parts illustrated in the drawing, a comparatively slight contraction serving to free shells 3 for removal and mounting endwise on the mandrel. Segments 22 at their ends are recessed to form annular channels adapted to receive expansible and contractible packing rings 24 of rubber or other suitable expansible material compressed and held in position in operation by end plates 25, the outer circular peripheries of which fit slidably into the ends of the cylinder 3. Rings 24 in operation are expanded to seal the ends of shells 3 against leakage of ink into the mandrel in operation by the pressure of end plates 25.

End plates 25 are forced firmly inward by collars 26 and 2'7 threaded to fit on the threaded sections 1'7 of shaft 15, and provided with holes 28 for convenient adjusting purposes.

with an etched shell 3 mounted on the mandrel and gripped by segments 22, while there will be slight spaces between the edges of adjacent segments, these spaces are so small as to be negligible in so far as effect on the support of shell 3 for printing purposes under the doctor blade pressures are concerned and the mandrel provides an excellent and satisfactory support for the shell during intaglio printing operations.

To remove the shell or tube 3 from the mandrel, the removable bearing of the press is removed and collars 26 and 2'7 are turned so they will move to the right in Figure 2. This will resultin collar 2'7 forcing expansible segments 22 to the right along the inclined sections 19, and segments 22 will be drawn inward freeing shell- 3 from their grip, so that shell 3 may be removed endwise from the mandrel and replaced by a new shell. Collars 26 and 27 are then adjusted on the threaded sections 1'7 so that the segments 22 of the mandrel will expand and tightly grip the new shell. With the shell tightly gripped the collars 26 and 2'7 are adjusted towards each other to compress and expand the packing rings 24 so the ends of the shell will be tightly gripped and sealed against leakage of ink into the mandrel in operation. The removable press bearing is then replaced and the press is in condition for printing of the desired number of copies.

In Figures 5 and 6 a modified form of supporting mandrel is disclosed providing a suitable intaglio printing press mounting for the thin etched shells of the present invention comprising a metallic cylinder 31 of a diameter corresponding to the inside diameter of shell 3, mounted on shaft 32. A section of the surface of cylinder 31 is cut away forming a guideway 33 with inwardly converging plane side surfaces 34 (Fig. 6) and an in clined plane bottom surface 35 (Figs. 5 and 6) for tapered wedging key 36 which fits slidably in guideway 33. Key 36 is providedwith cylindrical surface section 3'7, which completes the cylindrical supporting surface for shell 3 in operation.

Key 36 is provided with an extension 38 adapted to rest in cut out section or recess 39 formed in cylinder 31 at one end of guideway 33. An adjusting screw 41 threaded through a suitable tapped hole formed in extension 38 and threaded into a suitably tapped hole in cylinder 31 is provided to adjust and to hold key 36 securely in position in operation.

Sealing cups 42 and 43 preferably of copper, of the thickness of the metal of shells 3 are pressed over the ends of cylinder 31 and abut tightly against the ends of shell 3 sealing the construction against substantial leakage of ink underneath shell 3 in operation.

To remove shell 3 from cylinder 31, the removable press bearing is removed permitting removal of cup 43 endwise. With cup 43 removed screw 41 is operated to withdraw tapered key 36 endwise from between cylinder 31 and shell 3. With key 36 removed shell 3 may be flattened slightly over guideway 33 and will then spring away from cylinder 31 sufliciently to permit its endwise removal from cylinder 31. A new shell 3 may then he slipped over cylinder 31, key 36 inserted between the shell in cylinder in guideway 33, and the. key wedged into position by operation of screw 41 to tightly grip shell 3. Cup 43 may then be replaced, and the removable press bearing properly positioned to support shaft 32, and the press is again ready for printing operations.

The present invention is applicable to any cylinder size now in common usein the intaglio printing arts, cylinders from 4 inches or less to 15 inches or more in diameter and up to 76 inches or more being effectively produced thereby.

It will accordingly be seen that novel and effective printing forms and novel methods and apparatus are provided especially adapted for use in the intaglio printing art, applicable to all existing types of such printing, which make intaglio printing available in establishments where the cost of such printing has heretofore been prohibitive and permit effective exact reproduction of designs over an indefinite period of time, thereby permitting marked commercial economies in the use of intaglio commercial printing, textile, wall paper designs and the like.

Having described preferred embodiments only of the invention, wide variations in the disclosed details will be apparent to those skilled in the art without departing from the spirit of the invention. Accordingly what is desired to be secured by Letters Patent and claimed as new is:

1. As an article of manufacture, an intaglio printing form comprising a hollow seamless selfsupporting polished open-ended cylinder with an electro-deposited copper surface suitable to receive an etching, the metal thickness of the cylinder wall being of the order of 0.005 to 0.030 of an inch.

2. As an article of manufacture, a seamless hollow open ended self-supporting tube of electrolytically deposited copper provided with a polished surface adapted to receive an intaglio etching; the metal thickness of said tube being suflicient to receive only a single etching.

3. As an article of manufacture, an intaglio printing form comprising a hollow self-supporting open-ended electrolytically deposited seamless copper cylinder with a polished surface adapted to receive an etching, the metal thickness of the cylinder wall being approximately from 0.005 to 0.030 of an inch.

4. A printing roller assembly comprising a tubular printing form; an expansible mandrel supporting said form; and sealing means to prevent substantial ingress of ink between said mandrel and said form during printing operations, said sealing means comprising an expansible packing ring disposed adjacent each end of said form.

5. A printing roller assembly comprising a cylindrical self-supporting metallic shell with a polished surface and a wall thickness sufiicient to economically receive a single etching; an expansible mandrel comprising a suflilciently large number of segments to form a substantially solid cylindrical support for said form; packing interposed between the ends of said segments and said shell to prevent substantial ingress of ink between said shell and said segments during printing operations; and means for holding said packing and said segments in expanded position within said printing form.

6. A self-supporting intaglio printing shell

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