US2100358A - Paperboard printing plate and process of making same - Google Patents

Description

Nov. 30, 1937. J. s. ROYSE ET AL 2,100,358

PAPERBOARD PRINTING PLATE AND PROCESS OF MAKING.SAME

Filed Oct. 28, 1935 INVENTORS.

J/IMES 5, Fol 5E. PHI/1. k. TUANEE.

ATTORNEY 5 Patented Nov. 30, 1937 i UNITED STATES PATENT PAPERBOARD PRINTING PLATE AND PROC- ESS OF MAKING SAME James S. Royse and Paul R. Turner, Terre Haute, Ind., assignol's to Thomson Symon Co., Terre Haute, Ind., a corporation Application october 28, 1925, Serial No. 46,971

12 Claims. (c1.1o1 4o1.1)

This invention relates to the process of forming areas of the pap beard Printing P t e ea printing plate and the printing plate resulting moved from the Supporting a from said process. It has also been determined that to obtain a The chief object of the invention is to form a pe Printing Surface Which does not mar 5 printing plate of paper board hara t become rapidly unprintable after few impressions 5 In the printing, for example, of billboard posthave been taken therefrom, it is highly desirable ing copy, the original standard sizes w 24 to seal the minute pores in the exposed ink-resheets each of which was approximately 28" by ceiving face of the P p b0a1din Other Words. 42", although recently this entire copy for a billto an f this printing surface from poss board has been reduced in sheet number and ink s r i ha a t a th u h very sli ht. to 10 creased in the size of sheet, to wit, ten sheets apalmost non-absorbing Character; proximately 43 by 60%". Th each h t This transformation is frequently necessary is of relatively large area and the material itself, and pa t l y so for large long s u e used in printing plates heretofore, for printing printing ink is t cky a d if the P e Printing such sheets, has been a material item of cost. face is but slightly porous, the ink i d t e 15 The chief feature of this invention consists in Will gradually u h rep at d s ti p rat the reduction of that cost Without destroying the result in marring of the plate p t n surface so length of life of the printing plate resulting that the resultant co w en printed, will not therefrom and without forming from the plate a have that uniformity and depth of Color d 2 commercially unsatisfactory sheet of bill board sharpness of outline which is characteristic of 0 copy. metal printing plate production. This sealing Of course, the invention can b applied t bonds the surface fibres together so the surface smaller sizes, although the total savings are not resists suction deformationas large in the aggregate The present invention, however, produces a Plates produced by this process have at the plate'which will produce Y comparable to that 5 present time been commercially utilized in runs producedholn metal Printing P It, of exceedin 1,100 impressions per plate this being 4 course, is understood that metal printing plates, the largest commercial order upon which the inparticularly of large Size hereihhefore specified, vention has been utilized to date, the same proare of Shh/able mum-Ply Wood baseducing one sheet of copy for approximately 1,000 to which is secured the metal face, usually of billboards, the extra 100 being the customary sheet Zinc, upon which is formed relief the overrun to compensate for spoilage in the running Printing portions and the comparahve P and board application of t posters tween paper board and the metal, result ng in a The process port-ion of the invention consists marked Saving will be self'evidehtin the utilization of a suitable base of billboard A thin solution ofiwhlte transfer lacquer not 35 sheet size or the desired size and to the same is only provides the Surface Seal fibre bond secured a, composite paper board structure result the plate printing surface but provides a surface ing in a composite plate for subsequent printing which more less Sensitive to the lead when t impression is form d therein. (graphite and the like) of an ordinary lead pencil 40 It has been determined that best results;and by m that the original of the copy m be la'ld out 40 the same is meant the finished sheet of copy for on a sheet and by rubbing pressure on pasting on the billboard, is obtained when the the copy applied to the lacquered faice g g paper board portion of the plate is resiliently and there results the transfer of sumc en ea mm the copy to the plate printing face to permit the 5 adhesively secured. to the supportmg base The workmen to follow the transferred copy lines and paper board portion of the plate includes two cut through the two layers of paper board to retypes Paper board one h hard and the move from the plate the portions which are to be other still harder and of a smoother and higher left blank cori'espondingto the portions which are calendered finish, the two being adhesively set t b printed by t l t nthe final paper o cured together preferably with a resilient union.' copy,

Also, since the paper board portion of the plate It has been found that in order to secure the is of multi-lay-er character, preferably the first best results in the final copy and since copy subtWO yers are secured tog throughout their stantially identical to that obtained from metal entire adjacent faces. When but two layers are plates is desired, due to the lack of rigidity and utilized, substantially all of the non-printing toughness of a. paper printin rfa as u tinguished from a metal printing surface, some cushioning or yielding effect should be provided and preferably this is obtained in the adhesive connection between the layers of paper board plate structure and between the composite paper board plate structure and the multi ply base structure. This type of connection also compensates for any irregularities in the thickness of the several pieces of paper board utilized. Usually, the resultant board is type high for mounting upon the bed of a cylinder press. such as a 6-0 fiat bed cylinder Miehle press.

The formation of the printing impression on the plate is made by sharp tools cutting through the multl-ply paper board stock to the multiply wood base and following removal of the portions so cut out, the printing surface remaining has removed therefrom the surplus lacquer or at least that portion which is not utilized in sealing the minute pores and bonding the surface fibres together and also if, as and when desired, all cement on the wood board base exposed by the removal of the paper board portions may be removed. The impression intended, therefore, stands out in relief and will print when inked, copy substantially of the same character as printed by a metal plate.

No claim, however, is made that the life of a paper board plate of this character is equal to that of a metal printing plate of equal printing character but it is asserted that for fairly large runs, a paper board printing plate is equally as satisfactory as a metal printing plate and much cheaper to produce.

Heretofore in the industry, in order to reduce the cost of these large metal plates, 9. rubber mat surface instead of a metal mat surface has been utilized and it has been determined that a paper board plate of the present invention has a length of life sufiicient for the usual requirements for which a rubber mat is utilized. In one size, the present cost of a rubber mat plate is about $8.50, whereas, the present cost of the present invention. (paper board printing plate) is only $1.25 or there results a saving in plate fabrication of $7.25 per plate. If these comparative costs apply to the largest size plates mentioned for the ten plates necessary to produce a one-color complete copy for a billboard, there is a saving in plate cost of stood by those engaged in the printing industry, there will be an additional saving in plate cost in the same proportion as to the number of plates required for the reproduction. I

Having now described in some detail the process of preparing a printing paper board plate, reference will now be had to the plate per se and in describing the same, further reference will be had to the process of preparing or forming it.

The full nature of the invention will be understood from the accompanying drawing and the following description and claims:- I In the drawing, Fig. 1 is a plan view of a printing paper board plate, the left hand portion having the printing face thereon in relief formation and the right hand portion illustrating the paper printing plate preliminary to the formation of the printing impression therein.

Fig. 2 is an enlarged sectional view taken on line 2-2 of Fig. 1, and in the direction of the arrows and substantially of a plate in the stage prior to final completion.

$72.50, and as will be well undera aioasse 3-3 of Fig. 1 and illustrates the printing plate in its final or completed form.

In the drawing, l0 indicates a suitable base. herein illustrated as of five ply wood stock. The numeral ll indicates a layer of adhesive which secures to the base the main body portion of the stock l2 in turn secured on its opposite face by the layer of adhesive iii to the liner It.

It has been determined that a suitable liner or facing sheet is one that may be designated as .020 red press board and that the main body of the paper portion of the printing plate may be what is known as point news board. The press board is what may also be termed a relatively heavy fibre board having a very hard surface. It is almost the thickness of card board. The news board is slightly less than in thickness.

The preferred method of assembling the plate structure is to coat one side of the 80 point news board with rubber cement and at the same time coat one side of the .020 red press board. These two coated surfaces are then allowed to dry naturally or may be dried more rapidly by forced drying. The cement coated sides of these two boards are then pressed together and this forms what may be termed the surface plate" and corresponds to the metal mat on the plate in the printing industry.

The base i0 is approximately A" thick and the unlined or unsurfaced face of the surface plate and one face of the base,-each is similarly coated with rubber cement,-is permitted to dry until the respective coated surfaces become tacky, and then are secured together by a pressure arrangement. In the drawing, the cement layers H and i3 are intentionally represented as slight- 1y thicker compared with reference to the liner or facing sheet M, the paper body l2 and the base it.

After the entire plate structure has been built up, as aforesaid, the impressions, as previously set forth, may be formed in relief thereon by cutting away the liner and body portion down to the base iii. This will form a printing plate of satisfactory printing capacity having reference to a fairly convenient number of printing impressions or printing workmanship equivalent to a metal plate. However, for a relatively large number of impressions and to insure perfect printing, it is preferred to seal or bond the surface of the liner or facing sheet. There is, therefore, applied to the exposed face of the liner a thin solution of lacquer. This seals all imperfections in the exposed liner or surface sheet and bonds the surface fibres together. This lacquer may be sprayed or brushed thereon. Greater uniformity, however, is obtained by the spraying application.

To facilitate the formation of the printing impression on the printing plate, instead of using a colorless lacquer, there is utilized a white lacquer. This is known as white transfer lacquer and it is more or less sensitive to an ordinary lead pencil. The transfer of the desired design to the printing plate is made by merely turning the design in its normal relation, which has been made by pencil on ordinary litho-paper, face down on to the lacquer coating and then transferring the lead lines or a part of the lead of the lines on the lithopaper 'to the printing plate and particularly to the white lacquer surface thereof by rubbing. This rubbing leaves a sufficient representation of the desired design in reversed relation on the white lacquer surface.

printing surface of the Any omissions in the design may be filled in by pencil, if necessary, and then the plate is cut by hand or by tools, as desired, and usually the cuts are carried through to the base In and preferably the cuts are inclined to the plane of the base as shown. After cutting through to the plane of the bwe, the parts of the printing plate which are not to print in the final plate, are removed from the base which thus leaves the intended impression or printing portion of the plate standing out in relief from the base l0.

After the plate has been completely out, all surplus lacquer on the liner face or facing sheet is suitably removed by the use of any desired lacquer solvent. Of course, the solvent does not remove that portion of the lacquer which seals the imperfections or adheres to the surface fibres for bonding thereof. It merely removes the excess surface coating It might be stated these imperfections' are extremely minute in character and usually are not visible to the eye, although they may in the long run due to ink suction action, if not eliminated as set forth, result in poor print ing in the latter portion of the longer run. The cement which adheres to the base following the removal of the cutout portions of the paper board portion of the printing plate is then suitably removed in any desired manner, leaving the exposed portion of the base l0 clear or relatively free from cement.

It may be questioned as to why a single thickness of paper board might not be utilized in the same manner that a single sheet of rubber or metal is utilized and in answering the same, it is pointed out that a single thickness of board, if of the news board type, does not have a hard enough surface and if of the press board type, is possibly too hard. Likewise, the addition of a cushion adhesive connection between the two compensates for irregularities therebetween.

News board stock as an exposed printing face, is not satisfactory because of the tackiness of the ink and a rough surface in the board printing face results after a relatively few impressions due to such ink suction, which in turn results in poor printing. It has been tried and the most satisfactory impressions have been only about fifty in number.

Also, it may be stated'that other types of board, heavier and lighter than 80 point news board, have been utilized with better results than just plain news board. However, it has been found that press board which has a high calendered finish and is relatively hard and built up to approximately 80 point, is the most satisfactory for use in the formation of a printing paper plate that will produce printing substantially equalin character to that obtained from metal plates.

It might also be stated the foregoing description has been directed to a printing plate, that is,

what is known as type high, in total thickness, although for purposes where such a height is not desired, the thickness of the plate may be varied accordingly.

It might also be added that the utilization of an imperfection preventing sealing medium prevents peeling of the liner for the liner face or surface will, after a considerable run, start to peel at its weakest pointthe imperfection-edge to the suction and tackiness of the ink in its repeated application to the plate and its repeated transfer to the paper to be printed.

In the drawing, [5 indicates the white transfer lacquer and the dot 16 in Fig. 2 represents the pencil transfer legending that has been rubbed on to the lacquer from the litho-sheet bearing the original design. I1 indicates the tapered or inclined cut and the surface l8 indicates the sealed printing surface of the printing paper plate.

The use of the lithe-paper with the lead im pression thereon and the subsequent transfer by rubbing of the lead lines upon the lacquer, it will be obvious, results in a mere surface addition and all of the corrections may be made previously in the copyon the lithopaper and no corrections will be subsequently required on the plate. Also, instead of tracing through a copy made in reverse form, thecopy is made in its original form and reversely applied. A better visualization of the completed copy may thus be obtained by this method. This method furthermore has the additional and more important advantage that the printing surface is not mutilated in the copy transferring step so that only the cutting tool need engage this surface and form the sharply defined edge, leaving in relief the printing surface without imperfections or irregularities in either the surface or the edge immediately adjacent thereto, which might result if a stylus were used.

While the invention has been describedin great detail in the foregoing description, the same is to be considered as illustrative, not restrictive in character, and as has been pointed out hereinbefore, various modifications of the invention, both in the product and the article, have been set forth, and these as well as others which will readily suggest themselves to persons skilled in this art, are considered to be within the broad scope of this invention, reference being had to the appended claims.

The invention claimed is:-

1. A printing plate including a supporting base and a printing body, the latter comprising a rela tively dense liner of paper board stock, and of but slight thickness, and a relatively thicker main portion of paper board stock secured at opposite faces to the liner and the base.

2. A printing plate including a supporting base and a printing body, the latter comprising a relatively dense liner of paper board stock, and of but 4. A device as defined by claim 1, characterizedby the main portion being approximately 80 point 3 news board.

5. A device as defined by claim 2,'characterized by each elastic adhesive connection consisting of rubber cement.

6. A device as defined by claim 1, characterized by the addition of a filler to the exposed face of the liner.

7. A device as defined by claim 1, characterized by the addition of a filler to the exposed face of the liner, said filler comprising a thin solution or white transfer lacquer permitting pencil copy transference and the major portion of which is readily removed following plate cutting.

8. The process of preparing a printing plate from paper board, including resiliently securing a facing sheet to a paper board body, resiliently securing the body to a suporting base, sealing the imperfection in and bonding the exposed fibrous surface of the sheet. and cutting in relief the i desired impression in both sheet and body preliminary to forming the printing impression.

9. The process of preparing a printing plate from paper board, including resiliently securing a paper board facing sheet to a paper board body, resiliently securing the body to a supporting base, sealing the imperfection in and bonding the exposed fibrous surface of the facing sheet with a copy-receiving medium, and applying the desired copy thereto preliminary to forming the printing impression therein.

10., The process of preparing a printing plate from paper board, including resiliently securing a facing sheet to a paper board body, resiliently securing the body to a-supporting base, applying to the exposed face of the facing sheet a copy receiving-medium, applying the desired copy thereto preliminary to forming the printing impression therein, and removing all surplus medium subsequent to impression formation and preliminary to printing therefrom.

11. The process of preparing a printing plate aioasce from paper board, including resiliently securing a paper board facing sheet to a paper board body, resiliently securing the body to a supporting base, sealing the imperfections in and bonding the exposed fibrous surface of the facing sheet with a copy-receiving medium, applying the desired copy thereto preliminary to forming the printing impression therein, and removing all surplus medium subsequent to impression formation and preliminary to printing therefrom.

12. The process of preparing a printing plate of paper, including forming a composite paper board plate structure on a supporting base, the structure including an outer facing sheet of paper board and an intermediate body of paper board, sealing the imperfections in and bonding the fibrous inkreceiving surface of the sheet, and cutting the printing impression therein prior to printing therefrom, the printing impression being in relief.

JAMES S. 'ROYSE. PAUL R. TURNER.

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