US1002658A - Method of treating molds used in the art of electrotyping. - Google Patents

Description

I York,

outrun STATES PATENT 0FFIo GEORGE E. DUNTON, OF NEW YORK, N. Y.

METHOD or TREATING Moms USED IN THE ART or ELECTROTYPING.

1 ,002, 658. No Drawing.

To all whom it may concern.

- Be it known that-I, GEORGE "E. DUNTON, residln at New York city, county of New tate of New York, a citizen of the United States, have invented certain new and useful Improvements in Methods of Treating Molds Used in the Art of Electrotyping; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

My invention relates to a new and improved method of treating molds, and more especially the wax molds used in the manufacture of electro-type printing plates in the art of electrotyping.

The material of which the molds are formed for the production of printing plates in-the electrotyping art is generally beeswax, ozokerite wax or like substance which contains an appreciable percentage of grease, oil or oily substance in its composition. In bees-wax, the grease is due to the presence of palinitin and in ozokerite wax, mineral wax, it is due to the presence of petroleum.

When pressure is applied to a form or cut in making the impression in the mold, it causes any grease or oily substance therein to be expressed or forced out and'appear on the face of the mold in the form of a thin coating or film, and said coating or film very troublesome and annoying to the electrotyper as it causes imperfect and faulty reproductions. Especially in case where the so-called half tone illustrations are being made, which are composed or made up of a collection of very fine dots, or in the duplicating of color plates where three or four or even more printings are necessary, the least variation from the original plate, such as the filling up of the minute indentations made by each dot in the wax mold, wouldresult in a thickening of the duplicate or reproduction and ruin the same.

More trouble has heretofore been experienced in the uncertainty of reproducing faithfully duplicates of the original half tone plates and by all the common well known processes, the finer dots of electrotype duplicates from half tones do not have their proper height or face surface, thatis, instead of having a well defined flat, clear out or sharp printing surface the points are Specification of Letters Patent. Applicationnled November 11 1910', Serial No; 591,893.

Patented Sept. 5, 1911.

rounded and lacking in height from onefourth to one-half of the original.

After a very carefulstudy and extensive experiments, I have demonstrated. the fact that the above conditions are due to the in the black lead from the Wax mold. The

deeper portions of the impressions in the mold, the points of the dots penetrating further into the wax, receive and retain a ,larger proportion or percentage of this grease and when the black lead is applied to the surface of the mold the retained grease in the dots distributes itself throughout among the particles of lead, with which it comes in contact, and holds the particlesfirmly together and in contact with the sharp edges of the bottom of the dot re.- cesses made in the wax. The use of a machine, either an air blast, wet method or brush type serves to pack the black lead firmly into the dots in the wax mold, and

the grease serves as a binder to cementthe particles of the black lead together and hold the mass at the bottom of the dotrecess.

Experiments have shown me that no amount of brushin blowing or washing, by using a spray 0 water undervpressure, will loosen or remove the congested particles of black lead from the wax mold, consequently when the deposit takes place instead of the metal going to the fullest depth of the dot recess it deposits over the accumulated film of black lead at the bottom of the dot recess, producing as a result round headed dots which have lost .just that, value the accumulated black lead has acquired at the bottom of the dot recess in the wax mold. The only manner whereby this surplus accumulation of black lead can be dlslodged or removed is to dissolve'the grease, oil or oily substance, which as has been said before is forced out ofthe mold, by treating it chemically when it may be easily removed.

Experiments have demonstrated the fact that the grease, oil or oily substance expressed from the mold can be removed by mixing a grease converting substance, preferably a chemical substance, with the black lead which is used to render the mold conductive, and that when the combined black lead and grease converting substance is applied to the mold it will convert the grease and also 'renderthe mold conductive, after which the converted substance can easily be rinsed or washed oil by water, chemical, mechanical or other suitable means;

By my method, before applying the black lead'to the mold, I mix a grease converting substance with the black lead and then-apply said combined substance 'to the mold, and after the grease has been converted into another substance, for instance, a saponaceous substance, I remove said converted sa 0- naceous substance from the mold by washmg saidimold with water, when the black lead and mold will be free from grease andready to go through the other necessary operations well knowniin the art, which are not neces-.

sary'to enumerate, when the mold will be in condition for use.

By the above method, which removes all the grease, oil or oily substance, the dots and recesses of the mold are left clear, and un- 4 obstructed and a duplicate or reproduction taken from the same it will be a clear cut perfect plate. I

What I claim is 1. The method of treating molds used in the art of electrotyping, consisting in mixing a: grease converting substance with a conducting substance, designed to render the mold conductive, applying the resultant combined convertin and conductive substance to the mold to simultaneously render it conductive and convert the grease expressed therefrom and finally removing the converted substance, substantially as described.

4 2. The method-of treating molds used in the art of electrotyping, consisting in mixmg a ease converting substance with a conductlve substance, designed to render the mold conductive, applying the resultant combined converting and conductive substance to the mold to render it conductive and convert the grease expressed therefrom and finally removing the converted substance by chemical means, substantially as described.

3. The method of treating molds used in the art of electrotyping, consisting in sub jecting the mold to the action of a combined grease converting and electric conducting substance and then removing the converte substance, substantially as described.

4. The method of treating molds used in the art of electrotyping, consisting in sub-- jecting the mold to the action of a combined grease converting and electric conductin substance and thenremoving'the converte substance by chemical means, substantially as described.

i In testimony whereof, I afiix my signature in the presence of two witnesses.

GEORGE E. DUNTON. i Witnesses:

H. BECKER, F. DUFF.