US2380718A - Manufacture of paper for stencil sheets - Google Patents

Description

July 1945- I. E. BERKOVITS MANUFACTURE OF PAPER FOR STENCIL SHEETS Filed NOV. 28, 1940 INVENTOR.

wlwwm Patented' July 31,- 194s. I

MANUFACTURE OF PAPER FOR STENCIL 1 SHEETS Irene wa Berkovl'tl, New rm, N. Y; Application November", 194p, seen! no. 301,535 a 12 cums (on. lei-nae) This invention relates to the manufacture or long fibre paper suitable tor the production oi stencil sheets as used in the art of duplicating or mimeographing.

Conventional stencfl sheets consist of paper Fig. l is a diagrammatic elevational view showing an apparatus for carrying out. the-invention.

made impervious to ink by suitable impregnati n or coating. When an impression is-eflected on the sheet by the type or a typewriter or a stylus,

Pig. his a similar view showing a modified apparatus which operates substantiallyautomati- In carrying out the invention, a web or cotton obtained from comberwaste by carding is prefthe sheet is made pervious to ink along duired lines to form an outline ionthe character or drawing to be reproduced. In this operation it is essential that the material of the sheet consists of long fibres or sufiicient strength to prevent the type of the typ writer or the stylus from cutting out the centers of loop letters or the like so that distortion of the outlines is avoided. After the necessary impressions have been made, one face of the stencil sheet is coated with ink which will pass throughthe sheet along the desired lines only, so that a true reproduction may be obtained one. sheet of paper brought into contact with the other race of the stencil sheet.

In the past. cil sheets of theabove character have been roduced from special long fibre Japanese paper, the so called Tosa Tensilio" paperwhich has the required strength. Various attempts have been made to replace this paper 7 by other products, but these substitutes have not been satisfactory for use in the stencil paper industr'y.

' One object or the present invention is to provide long fibrepaper which is made of readily available raw material at low cost and is equivalent or superior to Japanese paper regarding its q alities.

Another object of the invention is .to provide a method or manufacturing long fibre paper for stencil sheets. in which a thin carded web 01 octton or other downy or fiuiiy fibrous material or the type commonb employed in the textile industryasrawmaterialisusedasthestartingmaterial for making the long fibre paper.

A further object of the invention is to provide a simple and efiicient apparatus (or .the manufacture or paper for stencilsheets.

It is also an object o! the invention to provide a stencil sheet for duplicating or mimeographin'g purposes, which does not have an oily appearance.

Other objects and advantages will become apparent as the description proceeds.

For the purpose of but in no, sense of limitation, certain preferred embodiments o! the invention will be described hereinafter with reference to the aocompany ns drawins- In the marina,

erably used as the starting material. Such carded web. 01 cotton weighs approximately 12'to l yJm. and has heretofore been employed in the textile industry as a raw material. However, a carded web of downy or fiufiy fibrous textile material other than cotton may also be'used, for example, a carded web of wool, silk, or the like.

' When the apparatus shown in Fig. l is-employed, the carded web is first cut at a cutting stachamber 2 in which the blank is impregnated .well knownstiflcning'and adhesive substance or sizing material such as natural or synthetic-resin,

tion (not shown) into blanks a of a length and width corresponding substantially to the size of the desired stencil sheets. The cutting is preferably performedv in such manner that the fibres of the web material-extend in the longitudinal direction of the blanks. Each blank 11 is then supported by a member b 01 felt or the like whichv may be somewhat larger than the blank member, and both the blank and the felt areplaced on a conveying belt ito be advanced through a with an adhesive. The adhesive substance may be sprayed upon the blank and is supplied to chamber 2 in the direction of the arrow indicated at the upper end or the chamber. i r

The impregnation may be carried out-with any glue, starch casein, varnish, etc.

The impregnated blank is placed on a table 4 and covered with a felt member 0 similar to member b. The blank a'and felt members b. c are t then passed between a pair oi. rolls 3 heated to a temperature approximately to C. The

felt members protect the blank during this initial drying step and may'also absorb excess liquid.

On the table 8 the blanks are removed from between the felt members and then placed on the conveying wire I to be advanced through'the drying chamber 1. The dry blanks arecompressed ina hydraulic press (not shown), in which a plurality of sheets are preferably treated at the same time, and they are then ready {or use as paper blanks for the production of stencil sheets.

when producing such stencil sheets. the paper blanks will be impregnated or coated with a substance impervious to ink. While-such final impregnation usually renders Japanese stencil paper it is an additional-advantage or the improved material according to the present invention that due to its high absorbing capacity it is not oi such oilyappearancesothat itiseasier tohandle.

Referring now to Fig. 2, the apparatus illustrated therein performs most oi the necessary steps automatically. In the method carried out onthisapparatus,acardedwebdispsedwhich is disposed between protective paper layers e, j. The carded web and protective layers are provided in coil form on a reel 8 from which they are unwound, the protective layers being received by the winding reels 0,- ll, while the web is advanced by means of a conveyor H. nae endless flexible member a this conveyorconsists of felt or the like and one or bothof the conveyor rolls may be heated to dry the felt member. 'Ihe conveyor ll, will pass web d through the impregnating chamher 2 identical with or similar to chamber 2 shown in Fig. l, and throw a Pair of heat d. rollers l which correspond to rollers 3 of Fig. 1. In the embodiment according to Fig. 2, an andless i'elt member h passing over guide rolls l2, It, It is arranged tocover the upper lace of web 41 while the web travels through rollers 3'. One or more of the guide rolls l2, I3, I may be heated to dry ielt member 1:.

when leaving the conveyor 1 I, the web is passed through a suitable guide I i into a drying chamber ll 1 having a conveyor l1. Thereafter, the dry web is advanced by a conveyor It to cutting sta tlon it where it is cut into paper blanks of proper dimensions. The blanks are compressed in a hydraulic pressin the manner described in connection with Fig. l and are ready for use in stencil sheet production inwhich they will receive an impregnation or coating by a substance impervious to ink.

sions, and thereby providing a stencil sheet of normally ink-impervious character adapted to be vious stencil sheet adapted to be rendered locally ink-permeable by stylus impressions.

One particular advantage of the invention re sides in the use of a starting material which is:

readily available. Moreover, the long tlbre paper obtained by the method 01 the invention is conslderably cheaper than the "Tosa Tenguio" paper used at present in the stencil paper industry.

While cert'ain'prcierred embodiments of the invention have been described hereinabove and illustrated in the accompanying drawing, it is to be understood that the invention is not limited to the precise details so illustrated and described,

but that various changes may be resorted to without departing from the scope of the appended claims.

What is claimed is:

1. Thin fibrous sheet material adapted for conversion into stencil sheet by incorporationtherewith'ol ink-impervious material capable oi-being rendered locally ink-permeable by stylus impression's, consisting of a thin, natwisecompact sheet oi carded, predominantly parallel, long cotton fibers, said fibers being provided with adhesive 8. A stencil sheet comprising athin sheet base 5. A stencil sheet comprising a thin, compressed, ink-permeable. paper-like sheet of adhesively .cohering carded cotton fibers of the character used for making textiles, said thin, carded fiber sheet having incorporated therewith a coextending normally ink-impervious but stylus-penetrable film.

6. A stencil sheet comprising a thin, compressed sheet or carded cotton fibers or the character used for making textiles, said fibers being sized to constitute a coherent sheet and being predominantly disposed in parallel relation to each other, and said cotton sheet carrying a coating of ink-impervious material rendering said sheet normally impervious tothe ink, but capable oi being made locally permeable to ink by stylus impressions.-

7. A method'of manufacturing a base material for stencil sheets. comprising forming a thin web oi substantially long cotton fibers oi the character used for making textiles and applying adhesive material to said web and compressing the web to provide a thin, ink-permeable cotton fiber sheet adapted to be converted into a stencil sheet by application of ink-impervious material, said adhesive applying and sheet-compressing procedure including applying liquid adhesive material containing proper size throughout the cotton fiber web and drying the web, to eflect adherence of the. fibers together while maintaining ink-permeability thereoi, and compacting the web by substantially high pressure flat-wise thereof.

8. A method of manufacturing a base material for stencil sheets, comprising forming athln web of carded, substantially long cotton fibers, and applying adhesive material to said web and compressing the web to provide a thin, ink-permeable flat-wise thereoi.

9. A method of manufacturing stencil sheets.

comprising forming a thin web of carded, subatantially long cotton fibers, and converting said web into a stencil sheet by procedure includingsizing the web, compressing the web flat-wise and applying thereto a co-extending film of ink-imof compressed, predominantly parallel. substantil-11710118 cotton fibers in carded form, said nbers being adhesively secured together with paper sizeandsaidbasesheet acoatingoiinkimpervious material penetrable by stylus imprespervious stylus-penetrable material.

- 10. A method of manufacturing stencil sheets. comprisin forming a thin, ink-permeable web of carded cotton fibers oithe character used for making textiles. applying adhesive material to said web and drying and compressing the same to convert the web into a thin sheet of adhesivelysecured cotton fibers while maintaining the sheet in ink-permeable form, and converting said sheet v v act-acme to a stencil sheet by applying an ink-impervious,

' comprising forming a thin web of carded. substantially long cotton fibers, applying adhesive ink-impervious,

materiai to said Web and compressing the Web to provide a thin, ink-permeable cotton fiber sheet adapted to be converted. into a smcil sheet by application of ink-impervious mawrial, said adhesive applying and sheet=compressing procedure including applying liquid adhesive material containing paper size throughout the cotton fiber web, compressing the web while maintaining the same in contact with absorbent surfaces on opposite-sides, drying the web and compacting the same by substantially high pressure fiat-wise thereof, and converting said cotton fiber sheet into a stencil sheet by applying to said cotton fiber sheet a coextending film of ink-impervious,

stylus-penetrable material.

IRENE ELISETH BERKOVITS

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