US1857842A - Method of producing printing plates - Google Patents

Description

May l0, 1932. A FQQGOLDENBAUM] 11,857,842

METHOD OF PRODUGING PRINTING PLATES' Filed April 19, 1929 2 Sheets-Sheet l May 10, 1932. F. c. Go| |:n-:|\1BAUM 1,857,842y

METHOD OF PRODUCING PRINTING PLATES Filed April 19, 1929 2 Sheets-Sheet 2 Patented May 1932 UNITED `sp'lfariazsF PATENT OFFICE:

4FREDERICK c. GOLDENRAUM. or REARNY, NEW JERSEY, ymssIofNoR To HEREEErr moros, INC., or NEW YoRx, N. Y., A coRroRATIoN E NEW YORK mE'rRoDoE rRoDUcING PRINTING PLATES y Application led April 19,

the process and apparatus for vproducing the same. l

It is an object ofthe invention to provide practical and commercial methods of'reproducing in a flexible non-inetallic printing plate a printing surface for news printing of photographsand the like, preserving the high lights and liadows now obtained by th use of electroty es, copper engravings or zinc etchings in t e reproduction of photographs, advertlsing matter etc.

Another object of the invention is to provide a multiplicity of said flexible printing plates from a single original copper engraving or zinc etching so as to reduce the cost of news photographs, advertising material, etc., and facilitate the reproduction thereof by the printer. i

Another object of the invention is to provide a method of producing flexible printing plates capable of printing half-tone photo graphs etc. on which the photograph or ad-4 vertising material is provided and which is at the saine time provided with integral clear type caption and descriptive printing relating to said photograph or advertising material.

Another object of the invention is to provide an ap aratus and method whereby said flexible printing plates are provided in the process of manufacture with integral turned flanges to facilitate the securing of the saine upon the printing block.

Another object of the invention is to provide a method of producing flexible printing plates of the type described in whichthe lines in the copper engravin orzinc etching may be reproduced in a lea `niold positive under pressure without producing variations in thickness and imperfections in the'leadmold.

Another object of the inventionxistoprovide the publishers and printers in outlying cities with flexible non-metallic plates for printing photographs and the like at a lower cost than ,they can secure electrotypes for this purpose. f i

Other objects and advantages of the invention will appear as the description proceeds.

192s. ser'in No. 356,546.

Referring. to the drawings which illustrate -step/ofproducing thev lead mold from the copper engraving or zinc etching;

Fi ure 6 is an enlarged sectional view showing the production of a printing plate from the lead mold;

Figure 7 is a plan view of the multiple printing material used in proframe used in the production of printing plates from the lead molds;

Figure 8-is a sectional view on the line 8-8 of Figure 7 showing the lead mold,'printing plate and pressure block in position in the frame; and

Figure 9 is a sectional view of the lower portion of the frame with part of the upper section removed.

' vIn supplying a news -`photographic service,

advertising material, etc., particularly to Acountry newspapers, considerable diiculty has beeiiheretofore experienced inthe fact that newspapers, particularly in outlying sections, are often handicapped in securing electrotypes for. printing the news photographed -or advertising material to be reproduced and the cost of the electrotypes, plus the cost of the photograph or news service, often placesathis service at such a high gure as to be prohibited to theV papers of limited circulation.

I Aam, by my invention, enabled to supply `to newspapers in outlying districts a news photograph or advertising service providing them with printing plates of thin flexible material carrying the half-tone imprint of the photograph pr the like and adapted to be and take the imprint ofrall the fine lilies and printlng plates which can be .mailed to the various subscribing newspapers in the news photograph service at ay cost only slightly greater than the cost of supplying the photograph itself and much lower than the cost of mailing electrotype or stereotype platesor copper engravings.

According to my invention, a photograph 10 of any suitable subject matter is first prepared by the photographer o r artist. A copper engraving or zinc plate 11 is then prepared from this photograph carrying, in addition to thephotographic subject matter, al

suit-able descriptive caption or descriptive printing 11a to describe the subject'matter of the photograph, the said descriptive printing 11a being reproduced on a clear backthis mold. is pressed by the pressure to prevent the lead from being ground independent of the st-ippled half-tone or screen background on which the photograph is reproduced on the copper engraving or zinc plate. The copper engraving or zinc plate produced in thisivay is then used as the patrix for the production of a plurality of lead moldmatrixes 12 carrying an imprint of the photograph 12a and an imprint of the type or caption material 12b. Any number of lead molds 12 can be produced from the original copper engraving or zinc plate 11 by placing a sheet of lead of a suitable thickness, say .O inches. over the copper engraving or zinc plate and subjecting this to a pressure of from 5 to 15 tons per square inch to press the lead into the face of the copper engraving or zinc plat-e and reproduce on the lead mold the. high lights,-shadows and printing which appears on the original copper engraving or zinc plate. Inasmuch as the lead used for purpose must'be comparatively soft and flowing under pressure and the pressure is sufficient to canse-the lead to flow into free used lnterstices in the copper engraving or zinc plate. suitable means must be provided to prevent the lead from heilig squeezed out at the sides of the copper engraving or zinc plate. For this purpose, the copper engraving or zinc plate 11 shown with the lead 12 in position thereon in Figure 5 is provided along thc outer margins of matter to be produced with ridges 11b and depressions 11e around the margin thereof acting as dams into which the lead of the of the press squeezed out sideways along the edges of the copper enthe photographer other graving or zinc plate which would cause the lead plate to be thinner at the edges than at the center, producing an imperfect printing surface. The lead molds 12 produced by the pressure of the platen 13 upon the bed 13a of the press forcing the soft lead to flow into and receive the impression from the copper engraving or zinc plate 11'are placed in a suitable molding frame 14, consisting of a base 14a' having a depression 146 for receiv- 75 ing a plurality of the lead molds 12 therein having a surrounding frame portion 15 prof vided with removable separation bars 15a adapted by means of dowl pins 140 and openings 15a to be held in registry with each other. The lead molds 12 are assembled in the frame 14 and the edges of the frame 15 and 15a voverlap the edges 12e of the mold to retain the molds in position in the frame, and for the production of the printing plate, a sheet of suitable plastic, moldable material 16, such as fiberloid. (produced from a mixture of papel', camphor and alcohol), celluloid. or the like, is placed upon the frame over the lead molds 12 and vafter being heated to a softening temperature of from 225 to 250 F.,

on a suitable steam table or other heating device. thesheet 16 is covered by a resilient pressure member of felt or the like 17 and placed under av platen of a hydraulic or other press where a pressure of 25 to 100 pounds (varying with the high lights of the photograph and the thickness of the sheet 16) is placed upon thesheet 16 to cause it to take the impression of the lead molds 12. The sheet 16 is preferably of slightly greater Width than the width of the opening in the frame 15 so that when the pressure member 17, which is of slightly smaller size than the opening in the frame 15, is pushed into this opening, los right angle flanges 16a are turned up along two edges ofthe sheet 16 to provide a final printing plate 18 having integral'flanges 18a by which it may be secured on a printing block and carrying on its face a negative halftone photograph 18?). the printing or caption material 180 reproduced on a clear background. and the marginal raised and depressed border flanges 18d caused by the lead flowing into the ridges and depressions 11b 115 and 110 to provide a suitable margin or border for the picture. In many instances it is preferable to subject the lead molds 12, after having been pressed into the face fof the copper engraving or zinc plate. to a planing operation to smooth the back thereof and assure uniform thickness throughout. so as to prevent any lack of uniformity in the final printing' plate which would cause improper printing when inserted in the presses. ,The de- ,125 pressions 14?) in the frame'14 are of subst-antially the exact dimensions of the lead molds and correspond in depth to the thickness of the lead. so that the molds 12 are confined olf all edges by the depressions 14b and the over- 130 hangiiig of the frame 1'5, so that the pressure of the member 17 will not cause 'any ilow of the lead in the molds 12 when under the molding press. y y

As illustrated particularly'in Figures 7, 8 and 9, the frame 14, used in producing the printing plates from the lead molds, is provided with a bordering frame member with separate division strips l15a and lthe face of the frame 14 is provided with depressions 14?) approximately the thickness of the lead molds and of a size to receive lead molds cari'vin1r the ortion o the icture to be rethe face of the lead molds and, so as to confine the lead of the molds 12 from spreading y `under the pressure of the molding press. The

`-strips 15a in molding press is preferably water-cooled to quickly lower the temperature of the sheet 16 and the temperature of the molds and sheet is reduced to about 100 toI150 F. under the.

.pressproducing a hard surfaced flexible printing plate, capable of withstanding the` -wear and pressure of several thousands of printings'.' As shown; for example, in Figure 9. theouter frame 15 may be `removed from the frame 14, leaving the longitudinaldivision position therein, so as to permit the lead molds 12 to be inserted under the edge of thestrips 15a or the molds to be removed therefrom. the strips 15a serving temporarily to hold the lead molds in place while the-frame 15 is inserted thereover,

While the process has beendescribed with reference specifically to the reproduction of news photographs l on flexible non-metallic printing plates. it will be understood that the same may be used to produce any-type of printing material and to prepare from a single copper engraving or zinc etching or other set-up a plurality of flexible printing plates. l. therefore. desire that my invention be construed in a broad light in accordance with. the 7 terms of the appended claims.

What l claim as my invention is: 1. The method of prepari nga flexible nonmetallic photographic printing plate which comprises producing a half-tone copper engraving patirixl from a photograph, providing the copper engraving with a clear line printing caption outside the half-tone portion. preparing a' lead mold 'matrix -from the copper engraving carrying the halfftone photograph and clear' 'line printing material, molding the vflexible non-metallic printing plate from the lead mold by heat and pres-- sure and formingiutegral turned flanges on the printing plate during the molding process. ,I i

2. The method of preparing a flexible nonmetallic photigraphic printingvplate which comprises pr ucinga half-tone copper engraving from a photograph, providing the copper engraving patrix with a clear line printing caption and description outside the half-tone portion .and with ridges and depressions on the outer edges, preparing a lead mold matrix from said copper engraving by pressing th'e lead into the copper engraving and utilizing the ridges and depressions on the edges of the copper engraving to prevent `side-Wise flow of the lead under pressure and molding the flexible non-inetallic printing plate from the lead mold'byheat and pressure utilizing the ridges and depressions of the copper engraving as a border for the photograph. y v

3. The` method of preparing a flexible nonmetallic photo raphic printing plate which comprises pro ucing a half-tone copper engraving from a photograph, ,providing the copper engraving patrix with a clear line printing caption and description outside the half-tone portion and with ridges and depressions on the outer edges, preparing a lead mold matrix from said copper. engraving by pressin the lead intoq the copper engraving and uti izing the ridges and depressions on the edges of the copper engraving to prevent side-wis`e flow of the lead under pressure and molding the flexible non-inetallic printingv plate from the lead mold by heat sesl and pressure utilizing the ridges and depressions of the copper engraving as a border for the hotograph and forming integral int-urned anges on the printing plate during the .molding process.

4. The method of preparing a. flexible nonmetallic4 photographic printing plate which comprises producing a half-tone copper ein graving patrix froma photograph, provid- Anog the copper engraving with a clear line printing caption and description outside the half-tone portion aiid with ridges and depressions on the outer edges, preparing a lead mold matrix from said copper engraving by pressing the lead into the copper engraving and utilizing the ridges/and depressions onf v the edges of the copper engraving to prevent side-wise flow of the lead under pressure and molding the flexible non-metallic printing plate from the lead mold by'heat and pressure and confining the edges of the lead mold .from spreading during the printing plate molding operation utilizing the ridges and depressions of the copper engraving as a border for the photograph.

5. The method of preparing flanged nonmetallic photographic printing plates, which comprises preparing al copper engravin patrix from the photograph, providing sai patrix with a clear line caption and descriptive printing outside the halfstone portion, preparing lead mold inatrixes from said copion - trlx and frame and the plate: material, and

ressin a sheet of the plate material of` g arger imension than said frame into the frame and against the matrix to receive the imprint of the matrix and produce integral turned flanges on vthe sheet.

In testimony whereof I have a-llixed my signature to this specification.

FREDERICK C. GOLDENBAUM.

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