US1119498A - Material for building up printing-plates. - Google Patents

Description

S. E. DITTMAN. MATERIAL POR BUILDING UP PRINTING PLATES.

APPLIQATION FILED DBG. 27, 1913.

1,119,498. Patented Deo.1,1914.

MATERIAL FCR BUILDING 'UP PRINTNG-PLATES.

Specicaton of Letters latent.

Patented Dee. il, lllll..

Application led Deeember'?, 1313. Serial No. 808.951. L

To aZZ whom it' may concern Be it known that l, SAMUEL E. Diarra/IAN, a citizen of the United States, and a resident of New York, in the county of `New York and State of New York, have invent- `ed certain new and useful improvements in Material for Building Up Printing-Plates; and l do hereby declare that the following is a full, clear, and exact description there# of, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part or this specication.

This invention relates lto an improved article oi*l manufacture adapted for use in the art of printing and more particularly for building up forms in printing presses.

The process oin building up printing plates or leveling up plates as it is often termed i'sone commonly used in the art of printing, and consists of treating the printing plate in sucha manner that, portim'isA of the same, which are by tests found not to be at the required level for producingl the proper impression, are brought tou the proper level by applying patches of paper to the reverse face of the printing plate,

In the artl of building up printing forms in the manner heretofore unknown to the art as illustrated and described, for instance, in Letters Patent of the United States granted to Frank J. Slader, No. 984,859, in which Letters Patent l have acquired certain 'rights and interest, a material such as soap or wax has been applied to the plate and the latterI subjected to a pressure of the impression cylinder in ex-` cess of the degree of pressure required 1nV the operation of printing. The soap or Wax was crushed throughout the portionsunderlying the unduly high portions of the printing plate, thus spreading the material into the intervening spaces, and leaving the portions of the material underlying the relatively lower portions of the printing plate substantially unaltered or only crushed to such extent as to accomplish the necessary leveling required to properly buildup the plate.

The material heretofore commonly used was in the -form of numerous small disks ol soap and like nonelastic materials readily susceptible to crushing. These disks were preferably laid at suitable distances apart between superimposed sheets of pa er toaseure the protection andl retention@ the said disks. The operation of building up the plates was accomplished by depositing a number of these disks upon the back of the printing plate by means of a perforated plate, forming a die or mold for 'the disks, over' which was scraped a bar of soap or wax. 'lhe disks deposited upon the plate remained after 'the removal of the perforated. plateA andY a sheet was laid over lthe disks. The process is obviously commercially impractical as regards its application and use in the extensive and highly developed state of the printing art at the present day in that the large number of plates to be thus treated would result in a great loss of time and money in the preparation of the sheets for each individual operation. Furthermore, it would be impossible to manu- 'facture a large quantity of these sheets by the above mentioned or any known method and thus maintain a constant supply at hand, for the reason that the normally soft condition ot theA disks would require their almost immediate use. lt would be impracticable to place the sheets upon the market as an article of sale owing to their inability to withstand handling, storing or trans# portation such as a marketable product must undergo. Furthermore, lthe size of the sheets would depend upon the size of the perforated plate or die, hence in the treat= ment of large printing plates, the use of a very large die, or the repeated use of a single die, would in either case be an eX- pensive and laborious operation.

The principal object of my invention is to provide a durable and improved article of manufacture to be used for the purpose hereinafter described, that may be economically produced in large quantities; that may be bought and sold in commercial quantities upon the market, and that will not deteriorate or be susceptible to injury during shipment, or long periods of time occasioned by storage prior to use. To accomplish this end, l propose to produce an article of manufacture suitable for building up plates, in which the material adapted to be compressed to accomplish the proper treatment of' the plates, shall be composed of a material which is normally sufficiently hard or non-compressible to withstand the normal pressure to which it is subjected in thev operation of printing without being crushed or distorted to an extent which will adect the quality of the work, but capable of beeoy ' crushed or distorted by seven per cent.

ing soltened or rendered more plastic, prior to its use, by the application oi a lid uid agent, or in any other desirable manner, and which will reharden subsequent to the process ol' building up the printingf plate,A

My invention, ther/clore, consists inthe niatters bereinaiter described, more parn ticularly pointed out in the appended claims, and lully illustrated in the accompanying drawings in which,

Figure l is a vievv perspective slioivinge,l iny proposed' construction for the article ot manufacture embodying iny invention; 2 .is a cross-sectional view taken on line ne/Z, of llig.l l, showing a ol the building; up :material applied to a printing pl ltig, 3 is a cross-sectional view ol a roof torni oltliebuildinp; up material applied to a pruatingi plateo Referring to the drawings: Vl`lie article oit manufacture embodyingr niy invention, 'as herein illustrated and described, comprises a sheet A, oi? paper or other suitable flexibleor iibrous material ol suitable thickness and quality, upon the surface ol which placed a plurality ot cakes or disks tl, each liorrned ot' a'roaterial *which is by preiicrence normally sulliciently hard, strong,1 and rifyjid'to Vwithstand the pressure to which it is subjected in the operation ot printing and which is adapted to be soltened or rendered more plastic or compressible by nieans o'' a suitable solvent or other agent enable the disks to be compressed vvhile in a softened or relatively plastic condition so to conin pensate lor irregularities in the surtace ot' the printing1 plate. The disks are ol uniforni thickness and are arranged in any manner desired Without regard to regu larity, 'but spaced apart at sutlicient distances to provide, in etleet, a layer oi tcrial ol uniform thickness The material ol which l propose to make the vclisks l), by preference, embodies a cornbination olE substances, having such qualities as are adapted to renderthe disks sulficiently hard to resist the tendency to become handling in shipnientpor storage or in the operation o'l printing as already. suggested, to be capablo ol' being softened by theapplication thus bemg suscepsure ot the impression cylinder ot a printing press when in such softened condition, and to resume its normal degree ol2 hardness after' the disks have been crushed. d. inaterial having these qualities and which has been found in practice to be satisfactory lor the purpose ot this invention consists ot a composition ol.2 glue sixty-one per cent.,

6l%), Wheat tlourI tlurty-one per cent, llb), and `glycerin eight per cent. (8%), or a composition oit talcuninpoivder lorty (M70), deutrin, twelve 'mate-rial to which the disks per centa (l2%), starch, live cent (5%), water, tvventyeizt per cent, (26%), calcium clalorid tivo per cent. (2%), glucose sin per cent. (6%), formaldehyde tivo per cent. (2%), combined in the proportions indicated to obtain the desired degree oli hard? ness or rigidity and strength the desired decree of conipressibility and plas icity lor accomplishing the purposes ci? the invention. is a preferablel construction of niy inaF proved building up material, ll propose to apply the disks to the sheet of paper by ineans ol' its own adhesive qualities or in any suitable manner such as will sure the close adherence ol' the disks ther `s The sheets to which the disks are a '"ied inay be of any desirable size as, for insancc, a continuous sheet having` the :torno of a roll oi paper or other suitable tlesible or fibrous are applied in l prefer, however, lor applying;

any convenient manner.- to employ mechanical nieans the disks to the paper, means embodying, lor instance, a device adapted to torna the disks troni an adequate supply ol the composition ani to apply the saine to sheets or to a roll papercon` stantly fed 'to the device. in this nianner it is possible to manufacture large quantities the material, .las hereinbetore suggested, the dis rs are normally in hardened condi tion, .which condition they would assunse substantially at the time o application to the paper., r y' The l building` up l sheets, as they inay be called, which comprise the hardened disks securely atliued to the paper, are obviously ca-psble'oi3 being ship ed or handled Without the liability of injury, thus large quantities may be manufactured and put on the market in convenient torno, as, for instance, in rolls or packages of any desired number of single sheets.`

To render the sheets suitable for use itis necessary that the disks be softened in order that they be readily susceptible to compressing1 during 'the operation ot leveling up oi a plate,i For this purpose a suitable agent is employed as 'for instance, Water. This agent may be applied in `any convenient manner 'as by dipping,n the sheets in the liquid or solvent or spraying by ineans oiE an atomizer. Vllie softening operation is perfectly carried out just prior to the application of the sheet to the printing plate, requiring the v treatment hereinbefore set forth andmpressure sufficient to compress the disks While in a softened or plastic condition so as to cause the material ol which the disks are formed to conform to or compensate tor the irregularities in the thickness or the printingplate or the surfaces of the same in such a manner as to render the printing,1 surface uniform. The material of "which the disks or 'building up material is suoli mechanical termed being then to harden sons ressure applied in the operawithstand tien of printi l p @he operation of subjecting a printing plate to treatment with my improved form of building up material, consists primarily in securing a sheet corresponding in size to that of the plate, which may be cut from a.

roll er a large sheet of tl e material, in the les instance that such be the form of the supply at hand, lla

um. in l1 i^ z 2, `to the reverse side of the te D, cut or printing anv de kind upon its front or printing face, being preferably ap 'in contact with the reverse side of the printing plate, and preferably secured thereto by their own adhesive qualities.. rlhis plate with its backing of building up material upon its reverse face is then placed in position in the printing press, and upon passing it under the impression roller, the pressure ener-ted by the same will level up the plate by variously coinpressingthe disks under the portions of the plate that are slightly abore the desired printing levelL ln this manner the entire surface of the plate is rendered uniform or yreduced. to a uniform height corresponding to the desired printing level of thepresss lt is desirable that the pressure upon the plate and the lei/'elineup sheet be suicient to compress all f the disks to such an extent to compensate not shown, said sheet for any irregularities in the surface of the printing plate.7 For this reason it is desirable that the thickness of the-sheet and disks be slightly in excess of the height to which the most depressed points in the cut or printing plate are required to be leveled, so that all of the disks will be, by preference, inc-re or less compressed by the pressure of the impression cylinder. rllhe printing plate haring been leveled up by the compressing of the disks in the manner described, it is allowed to stand for a. short interval during which time the liquid softening agent will be evaporated and the disks will again become hardened to' their original condition,I The printing `plate may now beused for the purpose of reproducing printed copies therefrom.

@ne of the advantages of using this improved form of building up material, lies in the fact that the-material before being subjected to the pressure of cylinder may be softened to such a degree as to be readily compressible by the normal printing pressure of the impression cylinder, whereas in the process heretofore used, a pressure greater than the normal printing pressure of the impression cylinder was required to crush the disks of soap or Wax in that such materials maintained a constant red With'the disks B,

the impression' degree of plasticity. ln, this manner the necessitjv of applying a pressure greater ,than the normal is eliminated. Furthermore, the use of disks composed of material which rehardens subsequent to the process of softening the disks and the leveling of the printing plat-e., produces a backing for vthe plate much better suited to withstand long usage and handling of the printing plate, and the pressure of the impression cylinder in the printing operation, Whereas, soap, ivan. paper or the like materials incapable or being softened in the manner described are not suitable as a medium for withstanding excessive handling and pressures and which are known to be susceptible to variations of working conditions as for instance-of temperature or humidity.

.The application of a second sheet B, may i .be included in the manufacture of the building up material, thus providing additional means for protecting the disks from injury occasioned by packing, shipping and storing. ln the inanufacti-irel of a building up material consisting of disks interposed between tivo sheets of paper, the sheet B, Fig. 3, would bev applied subsequently to the application of the disks to the sheet A, and in such manner as to adhere to the surfaces of said disks.

lt is to be understood that any material such as cloth may be substituted for paper in the manufacture of my improved building up sheets, and that any desired quality of material may be used, v

ln view of the fact that several materials may be utilized in the production of an article embodying the features of my invention, l do not Wish to be limited to the material or composition described, except so far as set forth in the appended claims.

l claim as my invention :l

l, `ln the art of printing, a material adapted to be applied to the reverse face of a printing plate for leveling or building up the saine, comprising a sheet of plurality of cakes secured to said sheet, said cakes being composed of a material normally non-compressible under the printing pressures, and adapted to be softened to render them compressible during the leveling or building up process.

2. ln the art of printing, a material adapted to be applied to the reverse face of a printing plate for leveling or building up the same, comprising a sheet of paper and a plurality of disks, secured in spaced relation. to said sheet, said disks being composed of a material normally non-compressible under the printing pressures and adaptedito be softened by the application of a softening agent to render them compressible under the normal printing pressure during the leveling or building up process.

3. ln the art of printing, a material lGEi lil@

paper and a sheet, ancl censisting of a. material comprising glue, fleur ancl gyleerin.

5. An article oir manufacture, adapiecl 110e be used. for louiliing up printing plaies, comprising1 a sheet of paper, a plurality el' disks secured co the sheet and consisting of a material containing sixty-one per cent. (61%) of glue, thirty-one per cent. (31%) of Wheat our ancl eight per cenit. (8%) of glycerin, said. clislrs being adapted en be treated with Water se render them @enr pressible.

ln testimony, that l claim the eregoing as my invention l" alix my signature in rhs presence of two Witnesses, this lli clay el December A. D. i913.

i SAMUEL E. llfitnesses 2 linwoen V7. Bamm.,

w Y. "l 'm nl irl. nenes.

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