US1987541A - Method and apparatus for producing printing plates - Google Patents

Description

Jan. 8, 1935. G, TAYL R 1,987,541 I METHOD AND APPARATUS FOR PRODUCING PRINTING PLATES Filed March 3, 1933 1 I151. ---ABct- F455. [44/ A /J 1 F1 3 m A m n {1 1 INVENTOR. Zawrence G. Tag/or.

Patented Jan. 8, 1935 UNITED STATES PATEN OFFICE 1,987,541 1 METHOD AND APPARATUS FOR PRODUCING" PRINTING PLATES Lawrence Taylor. Miami, Okla. Application ach 3, 1933,-SerialNo; 659,561-

A 11 Claims. (01 41 25) My invention relates to a method and apparatus for producing printing plates, and has for its main object to prepare a form or design in relief and cast thereon a stereotype plate of a v-15 character to be employed in reproducing the design by the usual printing process.

Another object is to produce a relievo form or design matrix that is responsive to the heat of the casting, or to heat applied thereto before casting,

10 to increase the thickness and density of the matrix.

Another object is to provide a suitable coating material which is applied to a base to forma de-. sired design, which design is thereafter coated 15 over with a masquematerial of such nature that, when washed with a suitable solvent, the latter can be removed at those portions incontact with the design. The masque material is also of such nature that it will expand when in contact'with 20 the hot stereotype metal forming the plate that is'cast thereon, or by the. application of heat before the stereotype is cast.

otherobjects will become apparent from a study of the detailed specification which follows,

taken with the accompanying drawing, where- Figure 1 is a plan view'of an 'applied design;

Figure 2 shows a cross section on line 2-2 of Fig. 1. r a

Figure 3 is a view in cross section coated design;

Figure 4. is a view in cross section showing a stereotype cast onto a formed matrix; and

Figure 5 shows a plan view of a stereotype plate.

According to the present methods employed in printing, of which I am aware, the usual practice is to prepare printing forms by the process of photo-engraving. This process is not only expensive, but also requires an excessive amount of time to eifect the various steps necessary for that process. Furthermore, the art of photoengraving requires the employment of skilled workmen and more or less complicated apparatus.

According to my method and apparatus, .a stereotype may be produced in a minimum of time and at a very small cost as compared with the present methods. My process is particularly suited to the needs of a small newspaper plant which is not equipped to produce printing'plates of the photo-engraved type and its use by such plants affords a much desired saving in.the time and expense which results from the present dependence upon a specially equipped central engraving plant. 7 g p 55 My method contemplates the forming upon a 30 showing a suitable matrix surface of a design to be printed. I employ a novel and specially prepared material or coating in the form of a solution and apply the material to the surface in a manner to produce the design in relief. The design is made exactly as the printed proof from the finished stereotype is to appear. When the design is completed, it is permitted to dry, or heat is applied thereto to facilitate drying and a second specially prepared coating is brushed on immediately over the original design and in andaround it. The latter coating isprepared from a novel combination of ingredients and is of such nature that it will be caused to expand upon thexapplication of heat and for a specific purpose. The coated design is then dried'and additional coats are similarly applied according to the needs of the particular design. Thematrix surface, including the design and the masque coating, arethen washed with a solution that will loosen the upper coating at portions-adjacent to the design portions in a manner tov remove portions of the upper coating andthe material forming "the design, thereby leaving the designv configuration in and between the upper coating. Thereafter, the matrix is dried thoroughly by heatingand the molten type metal is cast directly upon the finished design which causes the remaining coating-to expand to make a deep depression in the stereotype, leaving the design in bold relief thereon- The coating material may likewise be expanded sufficiently by heat before casting to form a satisfactory printing plate when cast.

Referring to the drawing, a desired design 1 is applied to a surface 2 by coating thereon a quantity of what may be called my A-mixture, a preferred composition of this solution being 85% of powdered resin and 15% powdered a1- bumin dissolved in sufiicientgasoline or benzol to cause the mixture to fiow freely when applied by a brush or pen. Any desired color may be imparted to this mixture byadding a dye or printing ink. The use of powdered albumin is not necessary and a satisfactory composition is made with the resin alone dissolved as set out. 45 The addition of albumin improves the mixture. When the design is finished, it is permitted to dry naturally, or .sumcient heat is applied to cause the mixture to crystallize, more or less, and dry out. Other resin solvents such as carbon disul- 5 phide may be used.

.I now'ap-ply to the design a-coating of what may be termed a B-mixture, a preferred composition of which comprises powdered albumin 5%, dextrin 80% and bicarbonateof soda 15%, dis- 5 solved in water to form a semi-paste. This B- mixture is brushed on immediately over the original design and around it to form a flat surface. A mixture of these substances is adapted to assume a hard and crystalline form when given the wash described later and to expand upon the application of heat. One or more coats of this B-mixture are applied to the design and each coat must be dried, preferably by heating, before the next application. This lzi-nriix ture acts as a masking material and permits a ready removal of the design by use of a special wash= ing solution. For coatings of the nature described, a preferred andpractical wash liqtiic h'j I have found by experiments to be gasclineftlie action of which serves, in some manner,- to' ldosen the A-mixture which constitutes the designrand.

harden the B-mixture. The gasoline is preferably flowed onto both the coated side and rear side of the cardboard base. When the gasoline has evapcra'ted t6 some extent, the design is heated carefully but not sufficiently to expand the coating of B-mixture. The first wash and the application of heat ordinarily causes the desigma loosen; but arepetition of this procedure may benecessary. The design is further washed or brushed cut by means of cctton saturated in gasoline. Other suitable wash. liquids'are ben'zol, carben disulphide and turpentine.- The application of heatis not necessary in the washing process except te hasten the procedure. Equally geod results may be obtained bysubnierging the matrix material in the wash solution and permitting it to remain therein until the design cleans out easily. Ontlie drawing, numeral 3 indicates the B-Inixture coating. v

The final "step in my novel process comprises the step of casting the stereotype. The washed out and driedinatrix is placed a. usual "form of castingbox i, anda quantity of molten casting metal 5 is poured over the matrix. This metal flows into the depressed or washed out portions which-extend through the coating 3 to the level upper surface of the base 2.- 'Ihe'hea't fromthe melten metal will cause the B niixture coating 3 to expand in a manner to thicken this coating whereby to accentuate the molded design impression and increase its relief. a

The cast stereotype 5 forms an exact replica of the'design 1, but reversed end for'end whereby it maybe mounted in a printing press, inked and employed in the usual 'n'iannerfor impressions. If desired, the base member 2 may be made from transparent material which may be placed over a design to be reproduced and the latter may be traced by applying my A-mixture.

In a modified form of mymethod, I propose to apply a uniformlay'er of my B-mi'xture directly upon a base surface. After the same is dry, or partially so, a desired design may be etched directly through or on this layer. This layerof transparent B-inixtu're may be applied to a transparent base 2, and any design which is to be re-' produced can be placed under this base and the design may be engraved through or on this layer. In either case, a stereotype plate maybe cast directly upon this etched layer. The heat from the molten metal will cause the layer to thicken to permit a pronounced relief of thedesign on the finished plate. .If desired, the etched coating may be expanded by heat applied prior to-the casting step; The coating may likewise be expanded before the etching is done since the coating surface is more pliable afteribeing fully expanded by heatr While I have stated preferred proportions for the ingredients of both the A and B mixtures disclosed, it is to be understood that these proportions may be varied within reasonable limits without materially affecting the practical results of my process and such variations are intended to be embraced within the scope of the claims which follow.

What I claim is: r

1; The method of making apri-nting form'which comprises applying material to a plain surface to form a design, applying a coating to completely cover said design, treating said coating and de- With a solvent to remove the design and the seating in contact therewith thereby providing a; iha'trix, and casting a stereotype directly on said matrix.

2'; In a method as set forth in claim 1, wherein the coating applied to the design is formed from material adapted to expand with heat. 7

3. The method of making a printing form which comprises applying material to a plain surface to form a design, coating the design with a mixture oentaining dextrin, albumin and bicarbonate of sc'da, treating said coating and design with a solvent to remove the design and the coating in contact therewith, thereby providing a matrix, and casting a stereotype plate directly on said matrix.

4. The method or making a printin form which comprises tracing a design with a mixture of resin, albumin and a "solvent, applying a coating to completely cover said design, treating said coatin and design with a solvent to remove the design and the coating in contact therewith thereby providing 'a matrix, and'castin'g a stereotype plate directly on said matrix- 5. The method of making a printing form which comprises tracing a design with a mixture of resin and. a solvent, applying a coating tocompletely cover said design, treating said coating and design with a solvent to remove the design and the coating incontact therewith thereby providing a matrix, and casting a'stereotype plate directly I on said matrix.

6. In a method as set forth in claim 4, wherein the coating comprises albumin, dextrin and bicarbonate'of soda,- the heat from the stereotype metal adapted to expand said coating to increase the relief of said design on the plate.

'7. In a method as set forth in claim 1, wherein the plain surface is transparent to permit tracing thereon a design. appearing from its undersurface.

8. The method of making a matrix which oomprises coating a surface with a mixture of dextrin, albumin and bicarbonate of soda, engraving adesign upon said coating, and applying heat to said coating to increaseits thickness and provide full relief of said design.

9. The method of making a matrix which com- .pri'ses coating a surface with a mixture of albur'nin, dextrin and bicarbonate of soda, heating to increasethe thickness of-the engraving surface and to make said surface more pliable, and. engravinga design upon said surface.

l0. The method as set forthin claim 8wherein the heat is provided by casting 'a stereotype plate directly on the engraved coating. r'

' 11. A composite matrix board for use in forming designs'to be printed, comprising a transparent base material-and a transparent coating applied thereto, said'coating containing dextrin, albumin and bicarbonate of soda.

LAWRENCE G. TAYLO'R.

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