US2251295A - Method and apparatus for coating sheet materials - Google Patents

Description

TM WM.. y H. A. SHEESLIEY 2,251,295

METHOD AND APPARATUS FOR coATING SHEET MATERIALS Filed Nov. 2, 1936 3 Sheets-Sheet 1 NVENTR ATTO RN EY Aug E'H1941- H. A. SHEESLEY M935 METHOD AND APPARATUS FOR COATING SHEET MATERIALS Filed NOV. 2, 1936 3 Sheets-Sheet 3 lNVENTOR Horam (Www/@W BYMW JKM@ ATTORNEY Patented Aug. 5, 1941 METHOD AND APPARATUS Fon ooATING snEET MATERIALS Horace A. Sheesley, Portlandyltlaine, assls'ncr to Tuiide Products Corporation, Portland, Maine, a corporation of Maine Application November 2, 1936, Serial No. 108,789

Claims.

This invention relates to an vimproved method and apparatus for coating sheet materials, and more particularly to a method and apparatus for applying a uniform coating compound to sheet materials such as paper, paperboard, textiles, and the like, and also to an improved waterproof and greaseproof paper and paperboard which can be economically and expeditiously manufactured by my improved method and apparatus.

Paper and paperboard material have heretofore been treated with a coating of wax, parafiin or asphalt to make the same resistant to moisture. Wax and paraffin is expensive material, and to a certain extent difficult to vapply due to the heating and cooling treatment required. Asphalt is also diilcult and expensive to apply, requiring expensive machinery and equipment. A further serious drawback of Wax and paraiiin and asphalt coatings is that they are affected by heat and temperature changes. Wax melts at approximately 130 F. and at this `temperature will flow off and lose its waterproofing qualities. Both .wax,.paraln and asphalt soften to much lower temperature, rendering the surface sticky and tacky and generally undesirable for commercial purposes.

A coating resistant to the passage of grease and oil therethrough has long been sought for. Wax. parailin and asphalt coated papers are only partially resistant lto the passage of grease and oil therethrough and are not satisfactory, since they soften under moderately warm atmospheres rendering the same greasy, sticky and porous.

It is an object of my invention to provide an improved paper and paperboard material suitably treated so as to make the same waterproof, I

greaseproof and oilproof.

`.Another object of my invention is to provide a waterproof and greaseproof paper and paperboard which can be manufactured at low cost, quickly and expeditiously, which has greater strength and flexibility than treated papers heretofore provided, which will not crack or deteriorate by flexure or rough handling, which is odorless and does not deleteriousltr effect foods and other products packed therein, which is furthermore not affected by heat or temperature changes and which is a fire and combustion retardent.

Another object of this invention is to provide an improved coating composition which is substantially waterproof and greaseproof.

Still another object of this invention is to provide an improved method and improved apparatus for coating paper, paperboard, Paper stock of all kinds and other sheet materials which can be carried out expeditiously and economically and by which a high quality coated material can be produced.

Another object of this invention is to provide an improved `apparatus for manufacturing coated papers, paperboard, paper stock and other sheet materials which is low in cost as compared with apparatus heretofore used for such purposes, which can be operated with a minimum of attention and largely by unskilled labor, which is durable and lasting in construction, and which permits manufacture of coated paper and paperboard. and other coated sheet materials so as to produce a highly satisfactory and desirable product efficiently, expeditiously and at low cost.

Other objects of this invention will become apparent as the disclosure proceeds.

In accordance with this invention, the paper, paperboard or other sheet material to be coated is supplied in suitable rolls or in sheets. My improved coating composition is applied to the rolls or sheets by spray mechanism which applies a homogeneous and uniform coating on the sheet material as it moves continuously under the spray mechanism. Immediately after the.

application of the coating, the surface is subjected to a pressing and spreading action which forces still further the coating composition into the outer fibres of the sheet and spreads the coating in a smooth, even and homogeneous layer 'thereoven The coated web is thereafter run through a suitable drying chamber which operates to hasten the escape of the evaporable components of the coating solution and also hastens the solidication or hardening of the coating material upon the moving web.

It will be noted 'that the coating is applied while the stock is in dry or substantially dry condition and thus the web can Vbe easily and efficiently handled. 'Ihe coating composition comprises a latex4 solution which may be combined with a fat-free animal glue. such as fish glue, animal glue or gelatin. The ordinary vegetable glues such as those made from stanches now available commercially have not proven satisfactory. A suitable preserving agent, such as formaldehyde, is added to the mixture and a congeallng agent, such as an alcohol, is applied to the mixture whichserves to congeal the same when spread over the sheet or web material.

Various other features and advantages of the invention will be apparent from the following advantages, and the manner in which it may be carried outmmay be better understood by referring to th following description taken in connection with the accompanying drawings forming a part thereof, in which:

Fig. 1 is a top plan view of my'improved ap paratus for making the waterproofed paper and paperboard by the method herein described, cer,- tain parts being broken away to `expose the interior; i

Fig. 2 is a side elevational view of the complete apparatus, the apparatus-enclosing housing being broken away to expose the same to view;

Fig. 3 is an enlarged front elevational view of the apparatus showing particularly the coating applicator operating in conjunction `with the spreader knife to apply a uniform layer of the coating material to the paper surface;

Fig. `4 is an enlarged fragmentary diagrammatic view showing the arrangement of the spreader knife, the coating applicator, and ifdesired an applicator by which a suitable hardeningl accelerator may be separately applied;

Fig. 5 is a vertical longitudinal cross-sectional view of a coating apparatus designed to apply coating to both surfaces of the web; and

Fig. 6 is a magnified cross-sectional view showing a section of paper or'paperboard having my improved Waterproof greaseproof coating applied to both surfaces thereof. A

Similar reference characters refer to simila parts throughout the several views of the drawings and specification.

I have found that a mixture of rubber latex and fat-free glue provides an excellent coating material for the paper or paperboard. As illustrative of the general mixture used, a satisfactory coating composition has been made from a solution comprising approximately 50% to 60% of commercial latex containing approximately 40% rubber solids mixed with-approximately 40% to of liquid glue comprising approximately six pounds ,of water to one pound of fat-free glue solids. To this may be added a preservative, such as formaldehyde, and to retain the latex in a wo'rkable condition, standard ammonia may be added. The latex generally contains some ammonia and the amount to be added depends to a great extent on the speed at which coagulation of the latex is to be effected. Coagulation of the latex and the glue is effected by the application of alcohol to the latex glue solution, which is preferably applied during or immediately after the application of the latex glue mixture to the paper so as to prevent the possibility of any substantial coagulating action prior to the actual contact Vof the latex glue mixture to the paper surface. I have found that a coagulating material whlc contains a major percentage of alcohol, and

known commercially as Shellacol, has proven to be an excellent coagulating medium. To two gallons of the latex glue mixture comprising approximately of latex having approximately 40% solid rubber content, and approximately 45% liquid glue is added approximately one-half ounce of formaldehyde, approximately 4 ounces of alcohol or Shellacol, and a suicient amount of standard ammonia to keep the material workable until the coating has been applied. It is under- "stood that the proportions above given are illus- 4the paper or paperboard web as the web moves under the spray nozzles. The spray nozzles should be so arranged as to apply a uniform coatlng to the paper surface and to fully coat the same. 'I'he coated paper surface then immediately comes into contact with the spreader blade which serves to even out any irregularities and give the nished material a smooth and even texture, filling in any uncoated areas of the paper surface. 'I'he spreader blade also assists in forcing the coating mixture into the surface so that a firm bond between the coating and the paper is produced. It has been found that the alcohol or coagulating agent maybe added to the latex glue mixture at the nozzles where it is immediately ejected onto the paper surface with the latex glue mixture before it vhas an opportunity to coagulate the same. If the coagulating medium and the latex mixture are to be applied simultaneously the apparatus should be so constructed as to permit immediate ejection of both materials beforeV any marked coagulating action can take effect.

The coagulating agent may also be separately applied by spray nozzles as the web leaves the spreader blade. The coated web is then run through a drying tunnel which may be suitably heated to expedite the escape of the fugitive cornponents of the coating mixture, after which the paper orA paperboard may be' cut into sheets or wound upon the roll. It is also understood that my `process contemplates coating both sides of the paper or paperboard surface, if desired.

Under ordinary circumstances, it is known that late x and rubber compositions as generally manufactured deteriorate rapidly, and that in a few months time the solidified latex loses a great deal of its elasticity and toughness. I have found, however, that when latex is combined with the alcohol and formaldehyde in the above proportions, that a preserving action is effected which produces a coating which is strong, resilient, tough and durable, and is both waterproof and greaseproof. Nofdeteriorating effects are noted many months after manufacture. f The apparatus for carrying out my improved processmay comprise a spray apparatus A and a web-supporting, web-coating and web-drying machine B. The operating elements of the coating machine, as shown more particularly in l'igs, 1, 2 and 3 of the drawings, may comprise a supporting table including a horizontal frame I supported on the spaced legs 2, 3, 4 and 5. Suitable reinforcing struts 6 and 1 may be provided to stiffen and strengthen the table. Much of the operating apparatus is positioned at the head end of the table and if preferable, therefore, the legs 2 and 3 may be relatively closely spaced to support the weight thereof. A roll of the selected paper or paperboard P is supported by a shaft I0. The shaft I0 is rotatably mounted in suitable bearings I2 provided in each of a pair of brackets II supported by the table legs 2. The paper web P passes over a roller I3 having a resilient rubber surface. The roller I3 is xed to a shaft I4 which is rotatably mounted in bearings 2| provided in the supporting standards I standing on the table frame I. The coating material is applied to the surface of the paper P as it passes over the roller I3. To maintain the paper web in a fixed plane as the coating mixture is applied, it is preferable to provide a guide roller I I3 which is positioned between the paper roll P and the cylinder I3.

The'coating material is preferably applied to the surface of the paper P under pressure of from to 50 pounds per square inch. The apparatus for applying the coating solution is shown more particularly in Figs. 2 and 3 and may comprise generally a coating solution supply line 80 into which the coating solution is conducted through the conduit 8| from a suitable source of supply. The coating solution flows into the several branch conduits l82 each supplying a spray nozzle 83. Air pressure is used to expel the coating solution from the nozzles 83 in the form of a drenching mist, air under pressure from a suitable source of supply flowing into the air supply line 84. The air supply line 84 also has a plurality of branch conduits 85 extending therefrom, each branch conduit supplying its respective nozzle 83 with the desired air pressure which operates to expel the coating solution with the proper force.

formly coat the paper surface with the required amount of coating material applied to the proper thickness and density.

Further means, including a spreader knife 22, is provided which operates to spread the coating solution onto the paper surface in a smooth uniform layer which will produce a coating sufficiently dense and uniform to fully protect the paper web P from contact with `moisture or grease which may be applied to the coated Isurface. The spreader knife 22 comprises more particularly a heavy steel plate having thel bottom surface 23 thereof shaped to accurately conform to the cylindrical surface of the roller I3. The spreader knife 22 is vertically adjustable in suitable guides provided on the standards I5. More particularly, vertical adjustment of the spreader knife 22 may be accomplished by means of suitable adjusting devices comprising a clamp element 24, fixed to each end of the spreader knife 22, each clamp 24 being secured in a suitable slide block 25 adapted to vertically slide within a guide opening 26 provided in each of the standards I5. An adjusting screw 28, provided with a hand wheel 29 to manipulate the same, extends through suitable threaded openings in the sliding block 25. By manipulating the hand wheels 29 at each end of the spreader knife 22, it is seen that the spreader knife may be raised and lowered as desired to present the lower spreading edge 23 thereof in the -desired spaced position with respect to the paper web -P passing over the roll I3. Thus the thickness of the coating applied to the web P may be regulated. The spreader knife 22 and -associated guide block 25 may be removed from the standard I5 for repair or replacement by removing the guide plate 21 from its associated block 25, which guide plates retain the blocks 25 in fixed sliding position within the standards I5.

Preferably immediately following the spreading of the coating solution by means of the spreader knife 22, an additional solution which f standards 89.

will hereafter be called an accelerator, is preferably applied to the coated surface. The accelerator Imaterial contains constituents which will accelerate the hardening of the coating constituents and further assist in the escape of the fugitive components of the coating solution. The

applicator for applying the accelerator solution may be similar to that used in applying the coating solution, comprising an accelerator solution supply conduit a which receives the solution from a suitable source and conducts it into the branch conduits 82a. eachof which supplies the accelerator solution nozzles 83a suitably supported upon a bar -8'Ia extending horizontally across the moving web of coated paper P. Air under pressure from a supply conduit 84a passes into the branch conduits a and acts to force out the accelerator solution through the nozzles 83a under pressure. A sufficient number of nozzles 83a are provided to apply the desired quantity of accelerator solution to the coated Web. The nozzle-supporting bar |Illa is in turn supported by suitable uprights 88a having vertical telescoping adjustment with the supporting The accelerator` solution, upon striking the coating solution, operates to congeal and hardemftlle same and facilitate the escape of the fugitive or liquid components thereof.

It has been found that the accelerator solution under pressure may be supplieddirectly to the nozzles 83a which spray the coating material onto the web. 4The entry of the accelerator solution into the nozzles 83a should be so arranged so that the accelerator solution is not given an vopportunity to congeal or harden the coating solution before it strikes vthe paper web.

As soon as the accelerator solution has been applied to the web, the web passes int a suitable drying tunnel |00 in which the coating applied to the web is hardened and dried. The drying tunnel I IIIJhouses and encloses a considerable portion of the web-supporting table. A heated web-supporting roll 4I is fixed to a suitable shaft 42, the ends of the shaft being rotatably mounted in suitable bearings 43 carried by supporting brackets 44 resting on the table frame I. The roll 4I is driven in synchronism with the roll I3 by operating mechanism which will hereinafter be described; The coated web P2 in the process of drying is returned to the front end of the apparatus where it passes around a heated guide roll 45 fixed to a suitable shaft 46 rotatably mounted in bearings 4I suitably supported from the table frame I. If desired, the guide roll 45 may be positioned outside of the tunnel housing |00 so as to permit inspection of the coating to determine the progress of the drying action. 'The coated web P2 returns into the tunnel drier |00 and passes around a heated guide roller 5|] at the foot end of the tunnel. The guide roller 5D may be supported on a suitable shaft 5I rotatably mounted in suitable bearings 52 supported by brackets 53 fixed to the supporting legs 5 of the table. If further drying action of the web P2 is desired, the web may be again run through the drying tunnel to the front end thereof and passed around another heated guide roller 55 fixed to a suitable shaft 56 rotatably mounted in bearing 51 carried by suitable brackets 58 xed to table-supporting legs 3. The web P2 returns to the foot end o f the tunnel and passes out of same through a suitable opening 6E, at which point the coating on the web is dry and thecoated web may be wound upon a suitable roll or cut into strips. It will be noted that either one or both of the rolls 45 and 55 may be mounted inside or outside of the drying tunnel |00, as desired, and likewise the guide`rolls 4I and 50 may be mounted either inside or outside of the drying tunnel |00. A suitable heating medium, such as steam, is conducted into each of the rolls 4|, 45, 50 and 55 through a suitable supply conduit 42a connected to the hollow shaft which supports the rolls.

Suitable driving means are provided for driving the spreader roll I3 and the various guide rolls 4I, 45, 50 and 55 in synchronism so that no undue stresses will be placed upon the web as it passes around these rolls. The driving force, such as a belt driven by a suitable motor, is trained around the stepped pulley wheel I8, Which permits adjustment of the belt so that the apparatus can be run at any selected speed. Pulley wheel 8 is xed to a suitable shaft I9 rotatably mounted in suitable bearings 20 supported by the table frame. A train of gears, comprising the gear I6 fixed to the shaft I9 which meshes with gear II fixed to one end of, the shaft |4 of the roll I3, operatively connects the roll I3 with the drive pulley I8.

The va'rious guide rolls 4|, 45, 50 and 55 may be operatively connected to one end of the shaft I4 of the roll I3. Mo-re particularly, a bevel gear 3| fixed to one end of the sha/ft I4, meshes with a bevel gear 32 fixed to a longitudinally extending shaft 33 which operates to drivey tpe/guide roll 4I at the foot end of the apparatus.` ,/The shaft 33 may be rotatably mounted in suitable bearings 38 provided in the spaced brackets 34, 35, 36 and 31 fixed to the table frame I. A bevel gear 39 at the foot end of the longitudinal shaft 33 meshes with bevel gear 44 fixed to the shaft 42 supporting the guide roll 4|. The drive connection between the spreader roll |3 and the guide roll 4I is such that the peripheral speed of rotation of the guide roll 4I is the same as that of the spreader roll I3.

The guide roll 50 may be driven by means of a suitable drive connecting the shaft 42 of the roll 4I and the shaft 5| of the roll 50. This drive connection may comprise a sprocket gear 59 fixed to the shaft 42 of guide roll 4I over which is trained a drive chain 60 which is also trained over the sprocket wheel 6I fixed to the shaft 5| of the roll 50.

Guide roll 45 may be directly connected to the shaft I4 of the spreader roll I3 by means of suitable driving mechanism comprising a sprocket gear 62 connected to the shaft I4, a sprocket gear 64 attached to the shaft 46 of guide roll 45, the

sprocket wheels 62 and 64 being connected by a suitable drive chain 63.

Likewise,A guide roll 50 may be operatively connected to guide roll 45 by means of a sprocket wheel 65 attached to the shaft 46 of guide roll 45. A sprocket wheel |66 is attached to the shaft 56 of the guide roll 55 and nally a suitable drive chain 61 is operatively connected to the sprocket wheels 65 and 66.

The drive connection between the spreader roll I3 and the guide rolls 4I and 50, 45 and 55, is so arranged and adjusted that the peripheral speed of the spreader roll I3 and the various guide rolls is maintained substantially uniform, so as to obviate the possibility of any pulling stresses being exerted on the web passing around the same. It will be noted that separate drive means may be provided for one or all of the guide rolls 4|, 50, 45 and 55, if desired, although it is generally preferable to drive al1 the guide rolls as well as the spreader roll I3 from the same source of power so as to obviate the possibility of pulling stresses on the web which might otherwise deve op.

Suitable drying means are preferably provided within the drying tunnel to hasten and facilitate the drying of the coated web. The drying means may comprise a suitable arrangement of steam or hot water heated coils, an electrical heating device, or other suitable heating means. I have shown and illustrated in Figs. 1 and 2 a heating device which compriils a plurality of parallel arranged pipes '|0 suitably connected by elbows '|I to provide a continuous conduit of serpentine form. The inlet end 12 may be connected to a suitable steam or hot water supply. The cooled steam or Water may be withdrawn from the outlet 13. The steam or hot Water coils may be supported in suitable frames I4 suspended from the table frame I. While only one row of heating coils is shown in Figs. 1 and 2 itis understood that two or more rows of heating coils may be provided positioned between adjacent moving webs. The coils are designed to maintain the temperature of the tunnel at from 180 to 350 F. A suitable outlet IOI is provided in the tunnel to permit the escape of the evaporable constituents of the coating. It is understood that the tunnel |00 may be of any length necessary to effect the desired drying action of the coating.

There is illustrated more or less diagrammatically in Fig. 5a somewhat modified apparatus adapted to coat both sides of the paper web P. In the arrangement here shown the paper or paperboard P to be coated is reeled ol the roll supported on the shaft I0, which rotates in a suitable bearing I2 carried by a suitable supporting `bracket I I a. The moving web P passes under the coating solution spray nozzles 83 which applies the coating to one surface of the paper web. The web then passes under the spreader knife 22 and thereafter passes under the accelerating solution spray nozzles 83a, and then into the drying tunnel |00 where it passes around the guide rolls 4|, 45, 50 and 55 and 90. 'Ihe apparatus so far described may be similar to the apparatus shown and illustrated in Figs. 1, 2 and 3 and heretofore described. When completely or partially dried the coated web P2 passes out of the tunnel |00 through a suitable exit opening |05 and thereafter passes over a second spreader roll I3a which is similar in construction to the spreader roll I3 above described. It will be noted that the uncoated surface of the web P2 is uppermost as it passes over the spreader roll |3a. A second coating solution spray nozzle 83 constructed similar to the spray nozzle heretofore described, applies the coating solution to the uncoated face of the web before it passes under the spreader knife 22a, as the web moves toward the left as shown in Fig. 5. The spreader knife 22a may be mounted and constructed similar to the spreader knife 22 heretofore described, and operates to spread thev coating uniformly over the surface of the web. A series of accelerator solution spray nozzles 83a are positioned on the opposite side of the spreader knife 22a and operate to apply the solution to hasten the solidification of the coating solution. The web, coated on both sides, then passes around the rotatably mounted guide roll I06 .and then passes through the inlet opening |06' in the tunnel drier |00 where the coating last applied is dried and nally hardened. The coated web P4 passes around the driven guide rolls 4 Ia, 45a, 50a,

55a, and over the finalv guide roll 90a, at which point it passes out of tunnel drier through the outlet opening |01 and is Wound upon a ysuitable reel |00. The guide rolls 4|, 45, 50, 55 and 90 and also the guide rolls 4|a, 45a, 50a, 55a, and 90a may be operatively connected to and drive in synchronism with the spreader roll I3 in the manner heretofore described and may also be heated as above described. The apparatus herein described is adapted to coat both sides of the paper web and solidify the coating C so that the coating becomes homogeneously bonded to both surfaces of the paper web P, providing a coated paper P4 both sides of which is moisture and grease resistant.

In carrying out the process it is preferable to apply the coating solution immediately in advance of the spreader knife 22 sothat the coating is not given the opportunity to solidify to any appreciable extent before it is acted upon by the spreader knife 22a. The accelerating solution applied by the spray nozzles 83a is preferably applied immediately following the passage of the coated paper web from under the spreader knife 22a so as to effect an initial congealing and hardening of the coating before it passes into the drying tunn l |00. While the above arrangement is prefer ble it is understood, however, that the accelerating solution may also be applied-immediately prior to the passage of the coated web into contact with the spreader knife 22 and spreader knife 22a. The drying tunnel is of sufcient length to effect the case-hardening of the coating so as to remove any stickiness or tackiness therefrom as it passes around the guide rolls 45 and 55, where the coated surface of the paper web contacts these rolls. Where it would be inconvenient to provide a tunnel of sufiicient length to eiect this result it is understood that the coated web could be given a half twist so that the uncoated side of the paper web only would contact the front end guide rollers 45 and 55.

My improved method and apparatus is agapted not only for coating paper and paper oard material with any desired compound, such as that above described, but can also be advantageously used to coat other sheet materials, such as cloth, textiles and fabrics. It is, therefore, understood that where the words paper or paper web are mentioned in connection with the method and apparatus herein described and claimed, other webs of various sheet materials are also intended to be covered thereby. For example, waterproof and greaseproof cloth and textiles such as used in making raincoats, tarpaulin, oilcloth, linoleum, and like products, can also be manufactured by my improved method and apparatus herein described and claimed.

The invention embodied in this application is also directed to an improved waterproof and/or greaseprocf paper and paperboard, which is well adapted for the manufacture of various commodities, such as paper bags, paper cement sacks, waterproof and/or grease proof wrapping papers, paperboard containers, cartons and boxes, for the shipment and storage of numerous productsI of commerce, either granular, liquid or semiliquid in nature, and other products which require a Waterproof and/or greaseproof container or wrapper. f

While 'certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. The method of making coated sheet materials having waterproof and greaseproof characteristics whichincludes, providing a base sheet, preparing a. coating compound by mixing latex, an aqueous solution of animal glue, a tanning i agent and an alcohol, spraying a layer of the teristics which includes, providing a base sheet,

preparing a coating compound by mixing latex, an aqueous solution of animal glue, a tanning agent and an alcohol, projecting said coating compound over a surface of said base sheet, wiping the coated surfalce of the moving sheet into contact with a relatively rigid and stationary broad-edged element whereby to spread said compound uniformly over said base sheet and compress the compound into the surface fibres of the base sheet to provide an impervious coating, and removing the liquid fugitive components from the body under treatment.

3. The method of making coated sheet materials having Waterproof and greaseproof characteristics which includes, providing a base sheet, preparing a coating compound by mixing latex, an aqueous solution of animal glue, a tanning agent and an alcohol, projecting said coating compound over the surface of said sheet as it moves along in a lineal direction, wiping the coated surface into contact with a relatively4 rigid and stationary broad-edged element whereby to spread said compound uniformly over said base sheet as it moves along in a lineal direction and simultaneously compress the compound into the surface fibres of the base sheet to provide lan impervious coating, and removing the liquid fugitive components from the body under treatment.

4. The continuous method of making coated sheet materials having waterproof characteristics which includes, providing a continuous web of the base material, preparing a coating compound by mixing together from 40% to 60% of latex, 30% to 50% of liquid animal glue, a tanning agent, and an alcohol, applying said coating compound to the surface of said web during its lineal travel, wiping the coated surface of said moving web into contact with a relatively stationary broad-edged element whereby to spread said compound uniformly over and impress said compound into the surface fibres of said web during its lineal travel, and removing the liquid fugitive components from the body under treatment.

5. The continuous method of making coated sheet materials having waterproof characteristics which includes, providing a roll of continuous webbing of the ibase material, preparing a coating compound by mixing together from 40% to 60% of latex, 30% to 50% of liquid animal glue, a tanning agent, and an alcohol, projecting said coating compound over the surface of said webbing during its lineal travel, wiping the sheet to provide an impervious coating, removcoated surface into contact with a relatively rigid ing the liquid fugitive components from the body and stationary broad-edged element whereby to under treatment, and placing said coated webspread said compound uniformly over said webbing in a roll.

bing duringits lineal travel and compress the 5 HORACE A, SHEESLEY, compound into the surface bres of the base

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