US645374A - Process of forming paper-board. - Google Patents

Description

No. 645,374. Patented Mar. I3, 1900. K E noeens PROCESS OF FORMING PAPER BOARD.

(Application filed May 14, 1898.)

2 Sheets-Sheet l.

(No Model.)

m ML (5.

No. 645,374. Patented Mar. I3, I900.

K. E. ROGERS.

PROCESS OF FORMING PAPER BOARD.

(Application filed vMay 14, 189

2 Sheets--Shaat 2.

(No Model.)

Unwrap STATES PATENT KNIGHT E. ROGERS, OF MANCHESTER, CONNECTICUT.

hRocEss OF FORMING PAPER-BOARD.

$PEOIFIGATION forming part of Letters Patent N 0. 645,374, dated March 13, 1900.

Application filed May 14, 1898- Serial No. 680,743. (No specimens.) 7

T0 aZZ whom, it may concern..-

Be it known that I, KNIGHT E. ROGERS, a citizen of the United States, residing at South Manchester, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Processes of Forming Paper-Board, of which the following is a specification.

This invention relates to the art of making thick paper-board in a continuous sheet, and it is particularly applicable for making pressboard and the like, which when finished must have considerable strength and stiffness and a smooth polished surface.

The object of the invention is to provide a simple process for cheaply making in a continuous sheet or web out of inexpensive stock without extensive beating and with the ordinary simple machinery now in use good strong thick paper-board which will finish very hard and smooth without waste, which will not cockle or split when dried, and which may have its opposite faces differently colored or of different qualities of stock without afiectingthehomogeneityoftheboard. Thick board of this nature can be produced in sheets by winding on a press-roll a number of plies of wet pulp from the felt of a cylinder-machine until the desired thickness is reached and then cutting the pulp from the roll. These wet plies directly from the vat are of such constituency that they will adhere into a practically homogeneous mass when pressed. Such sheets are limited in length, however, to the circumference of the roll upon which they are formed, and one surface will bear the marks of the felt. Besides the waste incident to the imperfectly-finished edges of short sheets sheets require much handling and when dried in a loft buckle and crinkle, so as to cause considerable loss in finishing,

. and sheets cannot have their opposite faces at best. Anattempt has also been made to form thick board in a web by forming a web of single ply, which after having been partially pressed and in a moist condition is passed between press-rolls with a newly-formed web of pulp. With such a process, however, the thickness of the material is limited, and one ply having been pressed more than the other the fibers are drier and more compact. Therefore the adherence of the plies at most is only partial and the finished, stock easily splits apart. \Vith a cylinder-machine by the employment of a number of cylinders with du= plicate felts and complicated machinery press-board of moderate thickness can be made if the best of stock is used, and a long time is consumed in beating and mixing; but even with the best of stock and a most extensive reduction the thickness of the board is limited by the adherence of the material, for after a certain thickness is reached the pulp is liable to drop from the felt or become airmarked when passing through the rolls. The application of wet paste or glue to thin webs as they come through a paper-machine is impracticable, particularly if they are wet, for

the cementing material soaks into and permeates the pulpy material, and thus loses its adhering potency, and penetrating the pulp and squeezing out at the edges smears the rolls to such an extent that the quality and finish of the surface of the paper are deleteriously affected. The present invention resides in a process in which as one of the steps there is applied to couched to the felt of a Fourdrinier papermaking machine of a cementing material in a dry-powdered form and then passing this powdered layer between press-rolls with another layer consisting of one or more plies of -wet pulp, and after repeating this until a sufficient number of plies of wet pulp with dry powder between have been brought together, then subjecting these plies to the action of hot drying-cylinders which steam,

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cook, and harden the cementing compound in the interior in such manner that it does not strike through the body of the material, but unites the plies into a web of practically uniform homogeneity and of sufiicient hardness to permit its being subjected to the most vigorous glassing-machines for finishing and polishing the surfaces.

Of the accompanying drawings, Figure 1 represents a cylinder paper-making machine with press-rolls, reel, and other mechanisms arranged for practicing the present invention; and Fig. 2 represents a continuation of the mechanisms shown in Fig. 1 that may be employed in carrying out the invention.

This process can be carried out and thick board formed with a single cylinder machine in the manner illustrated in Fig. 1. In that machine common paper-pulp stock beaten and mixed With only ordinary care is circulated in the tank 1. This pulp is collected by the cylinder 2, from which it is couched by the roll 3 onto the felt 4c, and after being carried between the first press rolls 5 is wound on a roll of the reel 6. The reel shown is of the revolving type, and when one roll is filled the web maybe cut and wound upon another. WVet webs 7 from two or more rolls of this reel are passed between press-rolls 8; but before passing these second press-rolls the inner surfaces of the thin wet webs of pulp are given an even coating of dry cementing material that has been finely pulverized. This cementing material maybe flour, starch,- or anything of a similar nature that when subjected to heat and moisture possesses the requisite adhesive properties and is capable of being finelypowdered. This powder may be sprinkled, dusted, or blown in suitable quantities evenly upon the surfaces of the webs. The powdered cementing material is placed in receptacles 9, that are supported by standards 10, so as to extend transversely of the machine between the webs. These receptacles are connected by pipes 11 with a fan .12, which is utilized to blow the powderfrom the receptacles to the surfaces of the webs. The moisture squeezed from the pulp as it passes through the second press-rolls dampens the powder and partially forms a paste, and the weight of the rolls spreads this evenly, besides tending to unite the plies. The web 13, thatis now formed of three plies, can be wound upon a roll of another reel lat. If it is desired to further increase the thickness of the paper-board, a number of webs 15 from this latter reel may be led to third press-rolls 1 6. These webs before passing between the third press-rolls have their surfaces dusted with powdered dry pastethat may be blown from receptacles 17, supported and arranged with a fan 18, as are the receptacles 9. The pressure of these rolls assists in the transformation of the powder on the inner'surfaces of the wet webs into paste. The web 19, that issues from the third press-rolls, will contain nine plies of wet pulp, and if this is of sufficient thickness it may be led to the cylinders of a drying-machine 20. In passing around and between the heated cylinders of .the drying-machine steam is generated from the moisture in the plies and this cooks the partially-formed paste, and as the web traverses the rolls this paste is gradually hardened as the board is dried and solidified until when the board emerges from the drier the paste has been treated and solidified in such manner between the plies that the finished web of board has practically the homogeneity of a single ply.

The paper-board formed by this process is when dried usually moistened and then subjected to the action of calendering-rolls or the vigorous polishing of a glassing-jack for giving the finishing polish to the surface.

By means of this process paper-board of any desired thickness may be formed into a continuous web of such homogeneity that it will not split or come apart when moistened for finishing, or when under the glassing-jack or other calender-rolls, or if it is moistened in dyeing liquor. Any ordinary single cylinder Fourdrinier or combination machine may be fitted for practicing this process, and it does not require the use of expensive stock nor is it necessary that a long and extended beating be given to the stock in order to insure a thorough adhesion between the plies of the pulp.

With this process the cementing material for the plies does not strike into the body of the pulp, but remains on the surface of the layers until thoroughly moistened, steamed, and set by the heated drying-rolls. By dusting the dry powder on the wet webs of pulp a very even distribution of just the sufficient quantity of material may be obtained to insure perfect adhesion without affecting the quality or color of the board. Vith the webs run together as described the surfaces with the felt-marks will be in the interior, so that the finished board will not bedisfigured. If it is desired, one web may be made of one color and another web a diiferent color, and these may be colored before being run together, so that the finished board will have its opposite sides colored differently. One ply may be made of cheaper material than the other or an inside ply may be cheaper than the two outside plies or of a difierent color from the outside plies, and still the resulting board will be very dense and have between continuously-moving undried webs, and dry and harden the board, substantially pressing together the webs thus dusted with as specified.

dry powder and subjecting the compound web thus powdered and united to heat and KNIGHT ROGERS pressure to form the moisture of the pulp Witnesses:

and the powder between the webs into a H. R. WILLIAMS,

strongly-adhering paste and solidifythe paste E. W. FOTHERGILL

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