US1181553A - Process of manufacturing paper-pulp. - Google Patents

Description

C. M. TAYLOR & H. K. COOK.

PROCESS OF MANUFACTURING PAPER PULP. APPLICATION men MAR. 16, m2.

Lmmm Patented May2,1916.

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M. TAYLOR AND HOWARD KAY COOK, 0F CAMDEN, NEW JERSEY. v

PROCESS OF MANUFACTURING PAPER-PULP.

Specification of Letters Patent.

Patented May 2, rate.

Application filed March 16, 1912. Serial No. 684,093.

To all whom it may concern Be it known that we, CHARLES M. TAY- LOR and HOWARD KAY Coon citizens of the United States, and residents of Camden, county of Camden, and State of New Jersey, have invented an Improvement in Processes of Manufacturing Paper-Pulp, of which the following is a specification.

Our invention has reference to the manufacture of paper and consists of certain improvements which are fully set forth in the following specification and shown in the accompanying drawings which form a part thereof.

Inexpensive kinds of paper are largely made from wood pulp, but such papers lack strength and necessitate, furthermore, the use of considerable sizing as a binder.

The object of our inventioffis to provide an improved paper and method of manufacture thereof from a Wood fiber embodying both tenacious fibrous character and selfcontained sizing or binding material.

More particularly, the purpose of the process herein described is the productionof a commercial paper of great strength at a minimum cost by the practical utilization of the waste by-products of banana plantations. This waste consists in the main of leaves, leaf stalks, stems, stem sheaths and trunk wood of the IL um. sapz'entum and III usa, paracZ-isiaca, which plants contain a large store of cellulose in the form'of parallel fibers and fibrous bundles, running from root to leaf-tip.

As the banana tree bears fruit but once and is then cut down and then becomes waste, there is an abundant store of waste material rich in fiber made available; and as these banana trees grow to a height from about ten to eighteen feet within each year,

and the demand for bananas is increasing constantly, it' is evident that this waste fibrous product is almost limitless in its natural production. and may be cultivated for the paper industry in case the demand should supersede the natural growth.

We have found that the cellulose fiber may be extracted from the refuse of the banana plant with comparative ease and that the fiber when so extracted is of a most excellent quality and particularly well adapted for the manufacture of a strong and tough paper, which not only may be satisfactorily substituted for the ra idly diminishing wood pulp supply in the manutreatment .into pulp, reduces to a great extent, if not wholly, the necessity for the addition of other sizing which has heretofore been necessary in other forms of paper making.

In the general carrying on of our improved process, we treat the waste product of the banana plant to a crushing and squeezing process to break. down the fiber in the direction of its length and at the same time squeeze out as far as possible the water and plant juices, and then subject the loosened fibers (preferably still attached together at one end) to the action of brushes which .brush or card the fibrous material to still further loosen up the fibers, separate them longitudinally, and remove any bark, scales, dirt, as well as other material present which is to be separated from the fiber. The fiber so treated and cleansed is then dried, and the dried fiber is cut up into uniform suitable lengths and placed in a boiler and subjected to the treatment of alkali, such as caustic soda, lime, carbonate of soda, or any mixture of these and preferably under low pressures. The boiling is preferably conducted at low pressure so as to reduce the disintegration and loss of the fiber to a minimum. The pulp so produced is then washed very thoroughly to remove the alkali and those resinous matters which may be held in mechanical suspension among the mass of fiber, leaving the fiber as of a light, yellowish-brown'color. The pulp so formed may be utilized without bleaching, such as in the making of wrapping papers, but if white paper is to be produced from the fiber, said pulp may be bleached by a solution of calcium-hypochlorite or other suitable bleaching agent. When bleached. the bleaching agents may be washed out of the pulp, and when thoroughly washed the pulp may then be delivered to the beating engine, and in this stage of the process there will be very little power and time required if the previous steps have been carefully conducted. From the beating engine, the pulp is delivered to the stuff-chests and thence to any of the ordinary paper making machines for producing paper in a web form.

The paper produced by our improved process possesses certain characteristics which impart to it the qualities of an improved article of manufacture. The fibers themselves are not brittle, but on the other hand, are elastic and possess great tensile strength. They felt together very easily, thereby enabling paper to be manufactured with a longer fiber than is ordinarily used. The gums and resinous materials in the plant associated with the fibers furnish sizing sufficient for most papers. The paper has great strength and toughness, yet it is light in weight. The paper is repellant of water to a high degree and hence is not easily saturated or moistened, which makes it a most excellent wrapping paper. The thickness of the paper may be varied within wide range, thereby enabling its application to the trade, from very thin papers through all grades of the art and fancy papers to heavy coarse strong wrapping papers, cardboard, and those tough grades of paper known in the art as imitation leathers. Being made from the fresh fibers rather than from old fibers previously used for cordage and rope, largely rotted, banana paper made by our improved process has longer life, is more durable and has greater power to resist abrasion and wear than many papers in commercial use.

We will now describe our invention more particularly with respect to the specific requirements for manufacture of paper from the banana plant, and to facilitate the same, reference will be made to the accompanying drawings, in which Figure 1 is a plan view of a set of breaking down or crushing and squeezing rolls adapted for use in the carrying on of our improved process; Fig. 2 is a side elevation of the same; Fig. 3 is a plan view illustrating suitable means for carding or brushing the crushed and loosened fiber; Fig. L is a side elevation of the same; Fig. 5 is an enlarged elevation of a portion of Fig. 4; Fig. 6 is a diagram illustrating the manner of splitting up the trunk or stalk of the banana tree to provide smaller sections for treatment; and Fig. 7 illustrates a portion of the plant after being subjected to the rolls and prior to the brushing or'combing operation.

After the fruit has been removed from the tree, the stalks, stems, leaves and other waste material may be subjected to the following treatment: The stalks are cut into lengths a little longer than the length of the rolls illustrated in Figs. 1 and 2, so that one end of the stalk may roject, as at G, beyond the ends of the rol s. The stem sheaths are separated from the trunk proper, or the whole stalk may be cleft or divided lengthwise' into a plurality of sections, as indicated in Figs. 6 and 7, to provide convenient sized pieces for treatment in the rolls and brushes. The material so prepared is placed upon the conveyer H, and by it is fed between the rolls A and B. The length of the stalk and the fibers thereof are parallel to the axes of the rolls as they pass between them and with the small end portion G of the stalk projecting beyond said rolls. Those portions of the stalk which pass between the rolls are crushed down and the ends of the rolls are slightly rounded, as at I, to prevent any shearing or nlangling of the fibrous material where it projects into the portion G. These rolls A and B may be driven in any suitable manner and may be supported in suitable housings so that they are positively positioned and capable of insuring a definite crushing action. The function of the rolls A and B is to remove as great an amount as possible of the water and plant juices in the banana stalks. any of the woody cells surrounding the fibers and fibrous bundles are crushed and loosened by this treatment, thus making easier their removal by subsequent portions of the process. After the crushed stalk has passed between the rolls A and B, it is conveyed by a conveyer J to rolls C and D where it is subjected to a further crushing and squeezing operation. These rolls C and D are made corrugated with rounded teeth and recesses, and adapted to engage with each other much like a pair of large pinions. The teeth may be of suitable size to properly act upon the materials being treated, and in the diagrammatic illustration, these teeth are illustrated on a coarser scale for more clearly contrasting them with the smooth rolls A and B. The ends of these rolls C and D are rounded, as at K, corresponding to the rounded edges I of rolls A and B. The rolls C and D are also driven in a positive manner and firmly supported in suitable bearings. They are designed to take hold of and thoroughly squeeze and crush the fibrous material to a far greater extent than what was done in the case of the rolls A and B. Moreover, these rolls and D are driven at a higher speed than the rolls A and B, so that they more speedily take up the stalks delivered by the apron or conveyer J and hence thus prevent any objectionable accumulation of the material on the table or apron between the two sets of rolls. The function of the rolls 0 and D is to remove some of the remaining water and plant juices, but their primary purpose is to bruise, soften, loosen and remove much terial associated with thefiber.

has been completed, the chain is again operof the outer bark, scales, dirt, woody paren-- chyma cells and to disintegrate, loosen and break apart many of the fibrous bundles, thoroughly crushing the stalk so that subsequent combing and cleaning is rendered easier, but at the same time, without materially injuring the fiber itself. When the stalks leave the rolls C and D- they pass upon the apron L from which they may be taken and subjected to .the combing. or brushing treatment. 1

The crushed stalk, after leaving the rolls shown in Figs. 1 and 2, may be considered as illustrated in Fig. 7, in which we have the uncrushed portion G constituting a head from which the loosened fibers M extend. To this part G may be attached a clamp N of any suitable construction, and said clamp connected to a chain 0 and by which the speed of delivery of the crushed fiber may be controlled in passing into the combing or brushing machine. This machine is illustrated in Figs. 3, 4 and 5, and comprises an inclined table T having a top portion T provided with a series of pins S. Arranged in front of the inclined table T are the combing or brushing devices E comprising an endless band R passing about rollers X'and provided with a series of brushes W having metallic or other stiff bristles which are caused to travel parallel to the inclined table T and in that manner brush or comb the fiber of the stalk which lies upon the table, as illustrated in Fig. 4. At intervals, among the brushes W are arranged transverse knives or blades V which act as scrapers.

The endless brushing and scraping devices E may be positively driven in any suitable manner and are continuously operated while the crushed portions M of the stalk are being fed forward and down the inclined table T. To control this feeding, any suitable means may be employed. In the particular mechanism shown, a chain 0 is attached to the clamp and said chain may be passed about the Windlass or a cross bar by which friction may be put upon the chain to hold it and allow of its being paid out 1 slowly. The tendency of the combing and scraping devices is to draw the fibrousmaterial down the inclined table and the chain is manipulated to control the gradual feed ing of the said material. After the fiber has been fully fed down upon the table T, the clamp N rests against two of the .pins S and the combing and scraping may continue for a given time necessary to fully comb out the fiber and clear it of the woody or pulpy ma- After this ated to withdraw the fiber upward from the table T. Any other method of combing out the fiber may be employed other than that which is here described, as we do not restrict ourselves to the use of any particular machinery or means for bringing the fiber into the clean condition. The cleansmg of the fiber may be facilitated by jets of water from a spraying nozzle P whereby said water may be utilized during the cardmg and scraping. operations of the fiber, the water running down the'incline of the table and saturating the fiber, said water carrying away matter removed from the fiber as rapidly as the same is freed.

When the fiber is subjected to the treatments above specified, it will be in long hanks having lustrous, silvery, white and flexible characteristics. The fiber will not have any brittleness or other objectionable quallty to the making of strong paper, but on the other hand, will have great tenacity coupled with cheapness which will produce a paper of exceptionally desirable quality suitable for wrapping papers.

The machine which has been above described is simple in its construction and mode of operation and is intended to be used in the tropical or semi-tropical countries where the banana plant grows, these machines being designed to be operated where labor cost is low. By removing the water and plant juices from the stalks and cleaning the fiber where the raw material is to be had, enables the fiber to be shipped at low costs to the place where the chemical and mechanical processes of converting it into pulp and paper are to be carried on, it being our purpose to prepare the fiber in condition for further treatment in any of the usual paper making mills with some changes in the process of preparation of the pulp to be described hereinafter. The prepared fibers are then cut up into substantially uniform lengths by use of the usual and well known machines now on the market for such purposes, and the prepared fiber thus produced is then placed in a boiler preferably of the usual revolving type together with the alkali solution, and the disturbance produced upon the fiber by the rotation of the boiler is made as light as pos sible to prevent chipping, breaking or disintegration of the fiber, but providing, however, for a thorough intermingling with the alkali liquors. The fiber is boiled with preferably a three-tenths per cent. solution of carbonate of soda, or with an alkali such as caustic-soda or lime, or any mixture of these. The concentration of the alkali solution will depend more or less upon the quired of the alkali solution, and the lower the pressure necessary to subdue the fiber. lVe have found that sodium carbonate (Na CO,) produces the most satisfactory results since the chemical re-agent is, cheap, the results are rapid, the boiling may be conducted under low pressure, and the disintegrationand loss of the fiber is a minimum. lVe, however, do not limit ourselves to the use of SOdllllll CfllbOllilt. The length of time employed in the boiling operation will vary greatly according to the strength of the chemical liquors employed, and the cleanliness and condition of the fiber, such time varying from one and one-half hours,

to six hours, according to the said conditions. During this action of the alkali upon the fibrous material, the original resinous and gummy matters are more or less dissolved for purpose of removal from the fiber or pulp by subsequent washing; but it is particularly important that in this dissolving of the resinous and gummy constituents of the fiber they shall not be wholly removed, as they are desired to be retained in suflicient quantity to provide the necessary binder to unite the fiber in its final use in the paper, thereby obviating the necessity of additional sizing or binder substances. During the operation of boiling the fiber with the alkali as above described, samples of the material are drawn off from time to time and tested to determine the percentage of resinous or gummy constituents remaining with the fiber, it being desirable to retain approximately ten to twelve per cent, or thereabout, of the original resinous or gummy matters in the prepared pulp which is to go into the actual manufacture of the paper, whereby said resinous and gummy matters are to act as the binder. for insuring the proper cementing together of the felted fibers forming the sheet of paper. The time of treatment of the fiber with the alkali will vary according to the strength of the alkali solution and the richness of the fiber material in the resins and gums or its resistance to being dissolved. As nearly as we can determine at the present time, 220 to 150 pounds of 60% caustic soda per ton treatment would consume from six to three hours, that is to say, where the amount of caustic soda or the alkali is least, there will be a longer period of time necessary for dissolving the parts of the fiber constituents to be removed than where the quantity of the alkali is greater, the time period required being substantially inversely to the quantity of alkali. lVhen the tests by sample indicate that approximately the right amount of binder gums and resins or either of them remain in the treated fiber, the action is then stopped and the fiber is subjected to the washing operation now to be referred to.

After the boiling operation, the pulp so produced is thoroughly washed to remove all alkali and a large portion of the resinous and gummy matters that may be held in mechanical suspension or in solution in the mass of fiber. After thorough washing, it will be found that the fiber is of a light,

yellowish-brown color and is capable of many applications without the necessity of bleaching. Such uses may include the production of a heavy paper or cardboard in imitation of leather, and suitable for decorative purposes. If bleaching is required for the purpose of producing white paper or lighter shades of paper, the washed pulp is run into a potcher and heated before any bleaching re-agent is added. If the fiber was originally cleaned thoroughly and the pulp washed well after boiling with the alkali, a very weak solution of calcium hypochlorite is suflicient to produce a fine, creamy-white pulp in a very short time. If the fiber cleansing was not thorough, the

boiling with the alkali solution produces' many dark colored, soluble, organic compounds, which to a more or less extent become embedded in the mass of cellulose and darken and stain the pulp. lVhile thorough washing tends to remove these suspended compounds, any neglect of this thorough washing will necessitate a stronger solution of the bleaching re-agents to insure the whitening of the pulp. Alth ugh sodium hypochlorite is slower in actio than the corresponding calcium salt, it has less destructive effect upon the fiber and consequently its use is more desirable. We, however, do not restrict ourselves in this respect. The bleached pulp with its naturally associated gums and resinous matters is then thoroughly washed to remove all traces of the bleaching agents, leaving the pulp for the beating engine. If all the previous steps of the process have been carefully taken, there will be economy in the action of the beating engine upon the fiber as but little power and short time would be required in this operation, in the case of the manufacture of the usual grades of paper. Pulp from the Mum sapz'entum and the Musa paradz'sz'aca requires much less beating than that demanded by the fibers of jute or those of a similar character and with which our prepared fibers most closely relate as to tenacity. The pulp produced in the beatin engine is now ready for delivery to the stu chests, and thence in its natural sized condition to anyof the paper making machines now in ordinary use. 7

We have not described and illustrated the details of the boiler or beating engine or the means for washing the pump, as these are of the ordinary construction and well known in paper manufacturing, but we have pointed out wherein our improved process may employ weaker solutions of alkali and bleaching re-agents and the boiling conducted under a less pressure than has heretofore been required.

As pointed out, the fibers contain resinous and gummy matters sufiicient to obviate the necessity of adding additional sizing, except in those cases where greater strength and finish is the main object, and in these cases additional sizing may be added to the pulp though less sizing would be required than that heretofore necessary in the making of papers from other fibers.

We have described our improved process and article, and while the description is intended to clearly disclose the full "nature of the process and results to be secured, it is to be understood that we do not restrict ourselves to the details, as these, both as to the machines employed and the steps of the process themselves, may be somewhat modified without departing from the spirit of the invention defined in the claims.

While we have referred specifically to the Mus-0; sapz'entwm and Mum paradisz'aca plants in their scientific names, it is to be understood that these are forms of the banana plant to which our invention relates generally, and therefore whenever we have referred to our invention as embodying the treatment of'the banana plant, we have intended to be understood as including both of these varieties of this plant.

Having now described our invention, what we claim as new and desire to secure by Letters Patent, is O 1. The herein described process for the I manufacture of paper which consists, in subjecting banana plant-fibrous material to pressure and abrasion to break the fibers apart, squeeze out thewater and loosen the barks, scales and dirt, cleansing the loosened fiber by brushing the same in the direction of their length, subjecting the fiber to boiling in an alkaline solution under pressure to remove most of the natural resinous and gummy matters but arresting the action of the alkaline solution upon thev fibers when the resinous or guinmy matters directly associated with the fiber have been reduced to approximately ten per cent., washing and bleaching the fiber to separate it from association with the remaining gummy or resinous matters, and finally producing a pulp therefrom from which the paper is made I without the necessity of additional sizing or binder materials.

2. The herein described process for the manufacture of paper which consists, in subjectingsthe banana plant to pressure, abrasion and cleaning to loosen the fibers, washing the loosened fibers so produced and subjecting the fibers to boiling in an alkaline solution under low pressure to an extent only as will leave a substantial portion of the natural gummy and resinous matters associated with the fiber to subsequently act as a binder, removing the alkaline solution together with the dissolved gummy and resinous matters by washing, and finally producing from the said prepared fibers a pulp containing a natural binder material from the original gummy and resinous matters the fibers in a direction away therefrom forloosening the fibers and removing the deleterious associated materials, subsequently subjecting the fiber to boiling in an alkaline solution under pressure to dissolve the natural resinous and gummy substances but arresting the action of the alkaline solution when approximately all but about ten per cent. of these substances have been dissolved, and finally washing and bleaching the fiber and producing therefrom a pulp containing a binder material formed from the natural gummy and resinous matters which have not been removed from the fiber.

4. The herein described process for the manufacture of paper which consists, in subjecting banana plant fibrous material to a preliminary treatment to prepare the fibers thereof to a condition for chemical treatment, and subjecting the prepared fiber to boiling in an alkaline solution under pressure and thereby removing most of the natural resinous and gummy matters but arresting the action of the alkaline solution upon the fibers when the said resinous and gummy matters naturally associated therewith have been dissolved except so much thereof as will act as a binder for the fiber in the finished paper, removing the alkaline solution and the dissolved resinous and gummy matters, and finally producing a pulp from said prepared fiber and its natural incorporated resinous and gummy matters from which paper may be made without the necessity of adding additional size or binder materials.

In testimony of which invention, we hereunto set our hands.

CHARLES M. TAYLOR. HOWVARD KAY COOK. Witnesses:

P. M. KELLY,

E. W. SMITH.

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