US1999260A - Coated paper and process of manufacture - Google Patents

Description

April 30, 1935. .1. E. SCHOPP COATED PAPER AND PROCESS OF MANUFACTURE Filed June 27, 1952 IN N TO K Jam E 056% A TTORNE V Patented Apr. 30, 1935 I UNETED STATES PATENT OFFICE COATED PAPER AND PROCESS OF MANUFACTURE John E. Schopp, Oak Park, Ill.

Application June 27, 1932, Serial No. 619,375

8 Claims. (01. 91-68) The objects of this invention are: one hundred parts by weight of clay or other pig- First, to provide varnished paper labels or any ment, fifty-three parts by weight of water and varnished paper that is of a superior quality and approximately seven parts by weight of dry casein. can be manufactured very economically, and a After this coating is applied in the conventional process for making the same. manner I partially dry the paper and then apply Second, to provide a coated paper suitable for a two pound coating containing about five parts varnishing and the process of making the same. by weight of dry casein to one hundred parts by Third, to provide such a paper that is imperweight of water. The paper is then dried and vlous to varnish and which will not change color after printing a coat of varnish is applied in any 10 when varnished. usual manner, such as by the use of a machine 10 Fourth, to provide such a paper that will not as illustrated in Fig. l-A or by what is known absorb ink or varnish that is applied thereto. as overlay varnishing, which is merely printing Objects pertaining to details and economies of the varnish on the sheet with the usual printing my invention will definitely appear from the deprocess. scription to follow. The invention is defined in Paper coated in this way is a superior product 15 the clalms. for varnishing and is in much demand. The var- The manner of carrying out my invention is nish is held up by the coating because of the layer clearly illustrated in the accompanying drawing. of adhesive applied after the original coating, in which: which makes the final coated paper practically Fig. 1 shows diagrammatically apparatus for impervious to varnish.

carrying out my new process and manufacturing I am aware of the well known process of applymy new product. ing two like coatings to a sheet and know that Fig. l-A shows diagrammatically apparatus such processes do not embody the advantages of for varnishing sheets of my improved paper. my process or produce my product. Fig. 2 shows diagrammatically a different type Referring to the drawing, my process in detail 25 of apparatus for applying coating. is as follows:

Fig. 3 shows diagrammatically a still different I is a roll of paper which is preferably a hardp of apparatus for pp y Coatingssized paper, which I have found gives better re- Hel'etofole, in Order t0 make a P p a e sults, although a soft-sized or unsized paper can 0 for varnishing, it has been necessary to use large b t t d by my rocess, 2 is a coating applying quantities of casein or other adhesive and to use machine comprising a color pan 3 and brass rolls a in white which is m re exp nsiv than cl y l and 5 through which the web 5 of paper passes. f r h coating in order to m k a p p r f h The lower roll 5 picks up the pigment from the class pr y my p To make a p p color pan and applies it to the face of the paper that is the closest to my paper but which is 1111- web 6, and the roll 4 is so positioned that it presses 35 satisfactory the P 'D necessary to use the paper and regulates the amount of coating as a C atin about O hundred pa by Weight applied to the paper. The device is conventional of satin Whi e to tw yw twenty-five parts and is illustrated only diagrammatically. y weig t of Casein- The usual Clay sized P The paper web 6 then passes over endless rubin which Seve pa s y Weight of Casein and her apron 1 running over rolls 8 where oscillating 40 One hundred parts y Weight O Clay are used is brushes 9 spread out the coating. The paper is 1101? a a yy means of y process I a fed along by means of perforated rubber blanket succeeded in making a better sheet more economiin having a suction means therein. The means Cally by pp yin tw separate in difi' ing illustrated are all conventional and are illustrated from one another in their nature. diagrammatically. 45

In describing my invention I refer to a fifteen In carrying out my process, in color pan 3 I pound coat. This is the usual paper terminology place a coating composition made up of one hunand indicates that the coating applied to the paper dred parts by weight of clay, fifty-three parts by is of such weight that the coating applied to a weight of water and fifty parts by weight of casein ream of five hundreds sheets of I paper twentysolution. Fifty parts of casein solution is equal five by thirty-eight inches weighs fifteen pounds. to about seven parts dry casein, and the solution Those skilled in the art will understand this terherein referred to is made up of one hundred minology without further explanation. parts by weight of casein, six hundred parts by In my process I first coat the web of paper with weight of water and five parts by weight of soda a fifteen pound coating containing approximately ash.

natural calcium sulphate, or any other pigment that may be used in the coating of paper. Instead of casein it is possible to use any adhesive used in coating paper or suitable for such use, such as starch or glue, and I do not wish to be limited to the use of casein alone, although it is the best adhesive now available. It is also possible to use any suitable alkali instead of soda ash in making the casein solution. The various pigments can be blended as desired and the adhesives can also be blended to obtain desired results.

After the paper has passed the suction apron ill it is festooned over sticks II for drying. At this point in carrying out my process, I dry the paper until it is partially dry. I prefer to leave about fifteen to twenty per cent of moisture in the paper, but this can be varied. I have illustrated the drying as .-by festooning the paper, which'is well known in the trade. It may also be dried by steam coils or blasts of heated air may be blown upon the paper, the only requisite being that the paper be dried.

The paper passes from the drying to a serie of wooden rolls I2 which are conventional and smooth out any wrinkles in the web.

The web passes then to a second coating applying apparatus I3 similar in all respects to the apparatus 2. The coating is then treated as before by oscillating brushes M and the web is fed along by suction apron l5 similar to suction apron Ill. The paper is then festooned on sticks l6 and dried, as is well known in the art, and passes over a metal guide I! through smoothing rolls I8 where it is wound on storage roll I9.

In the apparatus I3 I apply a coating difierent from that applied in the machine 2. I apply a two pound coating. To apply this coating I use a solution comprising thirty-five parts by weight of casein solution such as heretofore described, or about five parts by weight of dry casein to one hundred parts by weight of water in the apparatus I3. The coating is applied as before and the steps of treatment above outlined are followed. Instead of casein, any desired adhesive, as stated above, can be used, and it is not necessary to use casein in the apparatus 2 and also in the apparatus 13. Any desired adhesive may be used in either apparatus without departing from my invention.

The proportions of materials may be varied but they need never be raised to the quantities required by the former treatment. In manufacturing my product, I have referred to applying a fifteen pound coating to the paper and then applying a two pound coating of the adhesive. My invention can be used in varying proportions, and I have found that the second coating, to-wit, the adhesive, can be as light as or lighter than one pound. The proportions by weight of the pigment for the first coating may vary considerably from the ratio heretofore described. These factors are dependent upon the sizing of the paper to be coated and its absorptive qualities.

I have described the production of a seventeen pound coating. For heavier coatings a heavier coat is put on the paper in the first instance and the second coating may be as described or of a different weight, depending upon the conditions. The first coating is usually one that will stick to the paper but is not a coating that in and of itself would be sufiicient, although I have found that a much better sheet of paper can be made if a coating that was heretofore considered satisfactory is given a light second coat of adhesive.

The paper produced is coated by a bound coating of the clay with a thin overlaid film of the adhesive alone, which makes the paper impervious to varnish or ink.

In Fig. 2 I illustrate an apparatus 20 for use in place of either the apparatus 2 or l3. This apparatus has a color pan 2|, brass roller 22, brush 23 for applying the coating to the web 6 as it is carried around a bras roll 24. I

In Fig. 3 is an apparatus 25 that can be used in place of apparatus 2 or apparatus 13, or apparatus 20. A color tank 26 is provided with brass rolls 2'! and 28 through which the web 6 of paper passes. Nozzle 29 discharges the coating on the sheet and the rolls 2? and 28 squeeze it to regulate the quantity applied.

In Fig. l-A I show apparatus suitable for applying varnish to my paper. The varnish can be applied immediately after the paper is completed. This is not done if the paper is to be printed for labels because a varnished sheet will not take ink and the printing would not be protected by the varnish. The apparatus shown is for use in applying spirit varnish to printed labels or other sheets.

The sheets 30 are fed between rubber roll 3| and brass roll 32. The rubber roll 3| applies varnish taken up by brass roll 33 from tank 34. The labels 3!) are then fed to a continuous conveyor 35 which passes beneath suitable drying means 36, here illustrated as a hood with suitable inlets 31 for heated air. The labels are fed through the drying apparatus and are stacked as shown at 38. The varnish used is a copal gum and denatured alcohol solution. Other varnishes may be applied and the varnish may be applied by printing, which is known as overlay varnish.

The paper produced in this manner may be produced for wall paper as well as labels and is suitable for any use wherein a waterproof paper is desired.

Modifications of my process can be utilized for making a. paper that is very resistant to ink and the quantities of materials used may be lowered considerably and the paper thus treated will, although not suitable for varnish, be suitable for printing and be a superior product.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The method of making varnished paper comprising coating the paper with a mixture of pigment and casein in which the quantity of casein is suflicient to hold the pigment to the paper during manipulation of the paper in coating but is not sufiicient to permanently hold the pigment to the paper, drying said coating, applying a second coating of from approximately 1 to approximately 2 pounds in weight comprising casein only, drying said second coating and applying a coat of varnish.

2. The method of making paper for printing comprising coating the paper with a mixture of pigment and casein in which the quantity of casein is sufiicient to hold the pigment to the paper during manipulation of the paper in coating but is not suflicient to permanently hold the pigment to the paper, drying said coating and applying a second coating of from approximately 1 to approximately 2 pounds in weight comprising casein only.

3. The method of making paper for printing comprising coating the paper with a mixture of pigment and an adhesive selected from the class consisting of glue, starch and casein, in which the quantity of said adhesive is sufficient to hold the pigment to the paper during manipulation of the paper in coating but is not suflicient to permanently hold the pigment to the paper, drying said coating, applying a second coating of from approximately 1 to approximately 2 pounds in weight comprising said adhesive only.

4. The method of making paper for printing comprising coating paper with a coating having therein approximately parts by weight of pigment to 7 parts by weight of casein, drying said coating and then applying thereto a coating of casein of from approximately 1 to approximately 2 pounds in weight.

5. An article of manufacture comprising a sheet of paper made by coating the paper with a mixture of pigment and casein in which the quantity of casein is suflicient to hold the pigment to the paper during manipulation of the paper in coating but is not suflicient to permanently hold the pigment to the paper, drying said coating, applying a second coating of from approximately 1 to approximately 2 pounds in weight, comprising casein only, drying said second coating and applying a coat of varnish.

6. An article of manufacture comprising a sheet of paper made by coating the paper with a mixture of pigment and casein in which the quantity of casein is sufiicient to hold the pigment to the paper during manipulation of the paper in coating but is not sufiicient to permanently hold the pigment to the paper, drying said coating and applying a second coating of from approximately 1 to approximately 2 pounds in weight comprising casein only.

'7. An article of manufacture comprising a sheet of paper made by coating the paper with a mixture of pigment and an adhesive selected from the class consisting of glue, starch and casein, in which the quantity of said adhesive is sufiicient to hold the pigment to the paper during manipulation of the paper in coating but is not suflicient to permanently hold the pigment to the paper, drying said coating, applying a second coating of from approximately 1 to approximately 2 pounds in weight comprising said adhesive only.

8. An article of manufacture comprising a sheet of paper made by coating paper with a coating having therein approximately 100 parts by weight of pigment to '7 parts by weight of casein, drying said coating and then applying thereto a coating of casein of from approximately 1 to approximately 2 pounds in weight.

JOHN E. SCHOPP.

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