US2064985A - Treating rayon - Google Patents

Description

. 22, 1936. MCCONNELL 2,064,985

TREATING RAYON Filed April 2, 1935 3 Sheets-Sheet l Dec. 22, 1936. T. McCONNELL 2,064,985

TREATING RAYON Filed April 2, 1935 3 Sheets-Sheet 2 IIIIIIIIIIIIIIIII Dec. 22, 1936.

T. MCCONNELL TREATING RAYON I Filed April 2, 1935 3 Sheets-Sheet 3 Patented Dec. 22, 1936 UNITED STATES PATENT OFFICE TREATING RAYON Thomas McConnell, Northampton,

Mass, as-

Application April 2, 1935, Serial No. 14,260

9 Claims.

In the usual process for manufacture of rayon or artificial filaments by the viscose process, by that general series of operations sometimes designated as pot or centrifugal spinning, the

alkaline viscose solution is extruded from spinneret orifices into an acid coagulation or setting bath wherein incipient gelatinization ensues, the plastic thread being taken up by means of guides, passed up and over a Godet or similar wheel, and thence downwards through a rising and falling funnel into a rapidly revolving centrifugal box or basket, where the filamentous material, comprising filatures individually coagulated exteriorly but still partially gelatinous and plastic interiorly, are thrown against the sides of the revolving centrifugal, thereby building up on the wall thereof a layer of from one to two inches in diameter and three or more inches in height, and with a hollow interior, thus constituting a cake. In the usual practice, this cake is then placed in a room containing a super-saturated atmosphere, usually wherein steam is issuing,

, where they are allowed to remain a prescribed period in order to complete the gelatinization or precipitation in the interior of each filature, (that is wholly transform the cellulose material into a hydrated cellulose) the aggregation of which filatures constitute the spun filament.

One of the objects of my invention is to render a cake of hydrated cellulose filaments or rayon as obtained by the viscose process, more susceptible to after-treatment by increasing the permeability by opening the wind of the cake in such a manner that subsequent operations involving treatment with hot and cold liquids by those steps or operations necessary for purification and imparting to the rayon properties desirable in the trade, may be more thoroughly, uniformly, expeditiously and inexpensively carried out, and without adversely affecting to a substantial degree the desirable qualities of the rayon.

Another object is to open up the yarn for easy and uniform permeability by liquids without subjecting the filaments to abrasion or detri mental attrition, and still have the filaments constituting the cake remain in a satisfactory condition for subsequent winding and similar operations.

Another object is to uniformly increase the porosity of the cake as a whole, and hence facilitate further treatment of the same, including diminishing the final drying period at the conclusion of the operations involving liquid treatments applied thereto.

Another object is to decrease the diameter or thickness of the cake as a whole, increase the length and usually slightly decrease the diameter of the cake wall, thereby increasing permeability by increasing the surface area to the action of chemicals to be afterwards applied to said treated cake, without causing abrasion, deformation, rupture of filatures, fuzzing up, undue strain, or other untoward result which might adversely interfere with operations to which the filament aggregates may be submitted, during subsequent operations before offering of the same for sale, and afterwards in the arts upon being fashioned or fabricated into textile compositions.

Another object of my invention is to remove wrinkles, deformities and deformations, and/or irregularities in the lay of the filaments or the filaments themselves, usually resulting from other processes of cake treatment where there is applied to the cake a simple forward rolling motion and movement of the cake in a straight path has been made in order to increase the porosity and susceptibility of the cake as a Whole to chemical and physical treatment of the same.

My invention in substance is the treatment of a viscose rayon cake as taken from the spinning box or centrifugal, either directly or after further treatment thereof, and extend the cake and open it up in a mechanical manner by applying thereto while still in the wet condition preferably, an operation involving a plurality of simultaneously applied pressure movements. The individual movements are so calculated, adjusted and synchronized, depending upon the dimensions, contours and other factors involving the shape, size, dimensions, etc. of the cake, and the prior factors entering into the construction or physical build-up of the same, that said cake will receive the maximum of uniform opening up with a minimum of detrimental action of the filament substance. That is, that there is applied to the cake a movement or series of moveintermittently a combined frictional fluctuating and oscillating movement, couplied with a rocking, wavy, undulatory movement, whereby the following effects, among others, are produced upon and in the cake:--

1. The general or usual size of a cake, or a representative size of the same may be taken for purposes of illustration, as six and one-quarter inches in diameter, at the bottom of the cake (as it normally rests in the centrifugal basket), and six and three-quarter inches at the top, being about three to four inches high, and there being a taper of about one-quarter of an inch between top and bottom of each wall. The thickness of the cake wall varies within the near neighborhood of one inch, and should be built up substantially uniform throughout the cake mass.

In the building up of the cake substance in the centrifugal spinning pot, the filaments are usually deposited. so that a more or less openwork or reticulated pattern results, that is, be-

tween the filaments are voids, (somewhat dia-' mond-shaped) in which (speaking of the area) the two diameters may vary greatly intention ally or unintentionally, depending upon a num ber of factors, some of which still appear obscure. Therefore the pattern produced by the superposition of one filament passing on and over another in the normal building-up of the cake is of prime importance.

2. It is to be borne in mind that at the moment one filament is centrifugally flung against the filaments already in the spinning basket, the filatures constituting that filament are interiorly in a more or less plastic and incompletely gelatinized condition. There is evidence at hand to indicate that sometimes at least, the individual centrifugally deposited filament when flung against the filaments already present in the spinning bo-x, actually adhere to said filaments at the points of impingement, and. the amount or degree of adhesion will depend primarily upon the relative state of completeness of coagulation of the entering filament and the centrifugal force with which it is brought in contact with filaments already deposited in the centrifugal. Therefore, an opening treatment of a finished cake must, for optimum efficiency, take into consideration a treatment which will move each filament at the junction with, or where it crosses each other filament, by a degree, amount or distance, at least equal to the diameter of (say) the superposed filament, so that washing, desulfurizing and other treatments may be equally effective especially at those portions of the cake represented by the points or places or junctures where one filament crosses another, while that movement of filaments must be within such comparatively narrow limits as not to put upon thefilaments a sufiiciently undue strain as to cause rupture, fraying or interfere "with the desirable properties of the same.

3. This increase of porosity of filaments must be made in such a manner that knots, wrinkles and other defects are not introduced by the process per se. For instance, it is well known that a simple forward movement of pressure on a .viscose rayon cake diminishes the interior peripheryand increases the exterior periphery of the cake wall where the pressure is being applied. It has repeatedly been microscopically demonstrated that such treatment tends to produce wavy or wrinkled portions in the filament, which, because no subsequent operation is applied to the cake for the purpose of eliminating or minimizing the same, become permanent defects in the rayon filament. My process has for one of its objects to remove such contortions in the filaments produced by the forward rolling of the rayon cake, by the combination of both a forward and a return frictional pressure movement, whereby any wrinkles distortions, etc.

unavoidably introduced by means of the forward movement are nullified or neutralized by an immediate return or backward movement under conditions identical with the forward movement which produced the undesirable effect in the filaments. This to and fro movement upon the cake substance, is accompanied by an upward movement from a bedplate below the cake, which is of wavy or undulatory nature, whereby a rocking movement is imparted to the cake coincidental with the movement of said cake backward and forward; the combined series of movements adapting itself to the dimensions of the individual cake and producing the effect of uniformly opening up the cake throughout its length and the diameter of the cake walls, and also disturbs the filaments where they cross one another to the extent that there is now free movement of one filament from, over and under another, thus obviating the former adhesive tendency of the filaments where they were brought in contact during the spinning operation, and. hence causing the cake to maintain a maximum and even porosity and hence a maximum susceptibility to the series of treatments to which freshly spun viscose rayon is normally subjected, and still leave it at the close of the operations in maximum susceptibility and receptivity for drying,

' dyeing, etc.

An important feature of my invention depends upon the adjustment of pitches and movements to the end that the above results may be attained, and this, in turn, depends in a large degree upon the lay or the manner in which the filaments are deposited or built up in the spinning box, and the force (revolutions per minute) with which they are slung against each other in the building up process of cake forma tion. Also the denier being spun and the number of filatures constituting the denier of a given filament being of paramount importance, for upon the diameter of the individual filature depends the time required to so peripherically coagulate the same that it will not stick to a detrimental degree to the filaments already in the spinning box, when centrifugally impinged against and upon the same.

In the cake spinning process of rayon manufacture by the viscose process, the lay of the filament as the same is being built up in the interior of the revolving centrifugal, and the build-up of the cake due to the inter-meshing manner ofv depositing the semi-plastic filament in successive layers on the interior periphery of the centrifugal basket and afterwards upon the filaments deposited on said interior wall, is a delicate operation and one susceptible of great variation, and upon the manner of this build-up, the density, relative porosity and degree of agglutination of one filament superposed on another depends, and hence the facility with which the rayon cake may be submitted to the necessary subsequent operations.

Among the factors contributing to variation in build-up may be mentioned:-

1. Speed of the traverse, and where there is a dwell or hesitation in the traverse causing a build-up on either or both ends of the cake, thereby constituting an irregularity in that the diameter of the cake wall is greater at these points, thereby interfering with the uniformity of after treatment with liquids in the subsequent purification steps, and causing contortion, usually to a detrimental degree, by a forward rolling process to which the cake may be submitted to increase its porosity.

2. Relative size of the completed cake. This willvary within considerable limits by various manufacturers, and with the same producer depending upon the type of spinning machine used. In general, the larger the cake above the normal size, i. e. the greater the thickness of the cake wall and to a lesser degree the greater the height of the cake as it lies in the spinning basket, correspondingly greater difficulty is experienced in obtaining proper porosity of the same by the customary forward rolling openingup treatment, and hence greater difficulty in the subsequent purification steps to which the rolled cake may be subjected. I have found, speaking in generalities, that where the cake wall greatly exceeds one inch in diameter, correspondingly greater difficulty is experienced in obtaining uniform and satisfactory results when operating according to my invention.

3. The exterior and interior walls of the cake should be as nearly parallel as possible for best results. Difliculty has been experienced in synchronizing movements so as to uniformly open the cake where there is a considerable variation in cake wall thickness. Irregularities in wall thickness are mainly caused, in my experience, by improper adjustment of the rising and falling funnel, and/or by the spinning basket being improperly set especially as to centering.

As one illustration of a satisfactory mechanism embodying my invention which I have found useful in combining the movements to induce the effect desired of opening up uniformly a cake of rayon as obtained from the viscose process by the pot-spinning method by means of a plurality of frictional movements simultaneously and/or intermittently applied to the cake while the same is in motion, attention is drawn to the accompanying illustrations, wherein:-

Fig. l. is a front elevation of one form of the apparatus with the parts shown in their position readyfor receiving the cake to be processed.

Fig. 2 is a fragmentary vertical section taken on the line 22 of Fig. l, and showing the cake in dot and dash lines in its position on the spindle.

Fig. 3 is a fragmentary vertical section taken on line 3-3 of Fig. 1, and illustrating one form of swivel used to support the oscillating arms.

Fig. 4 is a plan section taken on line 4-4 of Fig. l, and showing the cake at the commencement of its movement.

Fig. 5 is a fragmentary perspective view of the cake being processed in accordance with one method of the invention.

Now referring to the drawings, the apparatus shown comprises generally a suitable framework, such as uprights l0, horizontal members H and i2, secured thereto, a table member l3, supported by uprights II] for supporting certain structures as described later, a superstructure l i carried on the member H for supporting a pair of oscillating arms l5 and H5, and driving means such as motor ii and speed reducer l8 carried on member I2.

The form of apparatus illustrated is adapted for processing a rayon cake (A in Fig. 5), whose shape is usually a frustrated cone having a hole therein of substantially the same shape. The means whereby the filaments or filatures constituting the filaments or both, in the cake are loosened from each other, and the cake mass rendered more open, more susceptible to aftertreatment, contemplates the use of and application thereto of substantially evenly distributed and comparatively light pressure being distributed thereto and thereon, said pressure being applied in such a manner and to such degree or extent as to attain the results hereinbefore described.

It has been found that a reciprocated and reciprocal rolling of the cake along a surface by means of a freely rotatable spindle inserted in the hole of the cake and maintained in a predetermined spaced relation to the said surface at a distance that will slightly compress said cake between the spindle and the surface, will produce the results desired.

In Fig. 5 there is shown a rayon cake such as might be produced by the viscose process for rayon formation by the centrifugal spinning method, in which both the hole in said cake and the outside contour of the same are tapered in the usual manner. The cake is denoted generally at A, the rayon mass 80 being enclosed in a covering 8| which may be, as is customary in the art, formed of a knitted fabric. The cake is pressed against the surface of a pressure plate 59 by spindle 29, the shape of which preferably correspondsat least very closelyto the contour of the hole in cake A, but is substantially smaller, so that only the lower surface of said spindle is in actual contact with the hole in the cake, that is, the pressure on the cake is between the lower portion of the spindle and the upper surface of 19, the cake being rotated during the pressure period.

Spindle is carried on spindle shaft 2!, and is freely rotatable thereon. Pressure plate it, although held in substantially fixed relation to spindle 29 during the rolling stroke, is so supported and adjusted as to permit a certain freedom of movement so that possible irregularities in cake formation may not be subjected to undue or undesirable pressure with consequent pos sible injury to the filaments constituting the cake.

It is obvious that if 28 be now moved back and forth across the surface of I9 in a path or are corresponding to that developed by the free rolling on said surface of a tapered object of the size and shape of cake A, said cake will be subjected to a rolling movement under light pressure, which will accomplish the desired result without undue or detrimental distortion of the cake shape due to friction, sliding either laterally or axially, unevenly applied pressure, or to other causes.

The machine illustrated in the drawings repre sents one form of mechanism adapted to move spindle 26 and plate E9 in the desired manner, but it is to be understood that other forms or combinations of movement may be used of an equivalent nature or to produce substantially a similar effect of rolling, and increasing thereby the porosity and receptiveness of the cake for aqueous treatments, and still be within the limits of my invention.

As embodied herein, the means for supporting spindle 20 comprises a shaft 2!, which is mounted in bearing blocks 22 and 23 in a manner to allow a limited universal movement therein, such as by the employment of self aligning bearings 24 or similar structures. Bearing blocks 22 and 23 are secured on the lower ends of oscillating arms l5 and I6, and with spindle shaft 2!, serve to maintain the arms in substantially laterally spaced relation, without limiting their are of oscillation to the same distance.

The upper ends of arms l5, B6 are provided with similar bearings, or bearing or pivot blocks 25, 26, having self aligning ball bearings ET. The pivot shaft 28, upon which arms l5, it are hung in spaced relation by spacer members 29, is fixed in hanger brackets 3t, 3!, carried on a plate 32, which forms the upper portion of the superstructure M.

It will be observed that if the arms E5, it are simultaneously oscillated through arcs of slightly different lengths the spindle 23 and shaft 25 travel laterally in a path such as is required to compress and roll a tapered shape substantially uniformly and without slipping to a detrimental degree and hence distortion. To properly accomplish this differential but simultaneous movement of arms i5, it there is provided a pair of crank discs MD, M, having their crank pins d2, 43 at different distances from their respective centers, for the purpose of producing diiferent length strokes. Links t l, 35 are pivoted to arms 15, It as at 46, and are connected at their other ends to crank pins 42, 43. These pivotal connections may either be of the ball and socket type, or simply a loose construction so as to allow arms l5, it the necessary freedom of movement, as determined by the different length of stroke of each.

Crank discs 433, M, are keyed to a common shaft 41, which is journaled in brackets 28, suspended from frame members H. A sprocket 39 on shaft 4?, serves to drive the discs, and is driven by the chain 56 and sprocket El on counter shaft 52. The latter is driven by sprocket 53, of the speed reducer iii, chain 54 and sprocket 55.

It is desirable that the movements of spindle 20 conform substantially to the rolling path of the tapered rayon cake. To produce this movement in the form of the apparatus illustrated herein, it is necessary that an additional movement other than the differential oscillation of arms l5, It, be imparted to spindle 25. This is attained by providing for a swinging motion of the lower ends of arms l5, it, which is perpendicular to their plane of oscillation, or substantially so.

A roller 5% horizontally mounted on the lower end of arm l5 by means of a bracket 5?, travels in a curved guideway 58, formed by two strips 553 secured to the table 13, and serves to maintain the travel of spindle 2i) in the desired path.

Pressure plate i9 is properly shaped to provide sufficient and proper rolling surface, and is concave in the illustrated form to compensate for the rise and fall of the spindle 23, due to the arcuate movement of arms i5, it. It is to be understood that the shape of this plate may be modified in many Ways to compensate for various other means of moving spindle 25, to provide for the rolling path of variously tapered or cylindrical cakes of different sizes, or of spools, bobbins orother similar articles.

It is desirable to mount plate l9 so that at one point in the cycle of the machine it is moved away from spindle 26, so that a cake may be readily placed on 20 or removed therefrom with such facility that the movement of the machine is not interfered with, and without injury to the err-coming or off-coming cake, by contact therewith. Said cake may or may not be surrounded by a protecting envelope as of textile or other material, and the effectiveness of my invention does not depend upon the cake being wrapped in any manner or with any particular material.

As constructed, a ball and socket bearing 60 is provided on oneend of plate I9 and is vertically adjustableby means of check nuts 6| cooperating with a threaded portion of socket 60 and bracket 62, fastened to the underside of table it. The opposite end of plate I9 is also provided with a ball and socket bearing 63, the ball of which is the upper end of a crank rod 64. This rod is pivotally secured to crank pin 65, formed on the hub of a pinion 66. This pinion and its drive gear 6? are intermittent gears so related that pinion E6 intermittently makes a half revolution at such intervals as the toothed portion of drive gear 61 determines.

In the form illustrated, the ratio of the various gears is such that at each second full oscillation of arms l5, It, the plate i9 is down to allow removal of pressed cake and insertion on spindle of unpressed cake. The intermediate oscillation takes place while the plate is in its upper or pressure position. Vertical adjustment of crank rod (it is secured by means of turn-buckle nut 68.

The pressure of plate i9 is resiliently held horizontally in both its operating and loading positions by means of two studs 18, secured in the corners of one end of the plate, and projecting downwardly through clearance holes in table It. Springs H are interposed between the heads of studs EU and the underside of table l3, to hold plate l9 substantially horizontal, except as some non-uniformity or irregularity of cake shape causes said plate to tilt to accommodate the same without distortion to an undue degree of the substance comprising the cake.

The operation of the machine is as follows:-

Operator starts the oscillating movement of arms 55, it, and at that alternate oscillation wherein the right side (as facing the operator) of plate 59 is lowered so that the clearance between spindle and plate is either at its maximum or else amply sufficient to insert a rayon cake on the spindle, said cake is inserted on said spindle, said spindle contacts with said cake, and said cake in turn is pressed against Hi to a degree which increases the length of the cake, while said cake is rolling (as indicated Fig. 5), both as to itself and its path along and on l9. The first return oscillation (left to right as operator faces the machine), and the second movement leftward, the cake is being pressed by 28 coming 7 in contact with A and forcing said cake against l9. During the progress of the second return oscillation, plate l9 as to its right side is being lowered, so that at or towards the completion of said second oscillation, cake A is free from l9, and may be removed from 20 and a new or untreated cake substituted.

That is, a cycle comprises two complete oscillations represented by a movement of 20 with cake thereon to the left, the return of the same by a right hand movement, a second left movement and a return of the same. As the spindle 29 returns to right side of plate l9, a processed cake is removed and an unprocessed cake substituted therefor, at the completion, or towards the completion of alternate oscillations. Frictional engagement of A on 26 with the surface of i9 is continuous successively during about the latter half of first oscillation to the left, return of first oscillation, first return to left of second oscillation, and about until the first half ill of the return of the second oscillation has taken place.

The first half of first oscillation opens up the filament masses, the second half of first oscillation smooths out or compensates any wrinkles that may have been caused by the first half of said oscillation, so that such irregularities, knots, wrinkles or irregularities are not formed during the first half of the second oscillation. This function having been performed, the maximum porosity having been imparted to the cake filaments with the minimum of disadvantage thereto as has been herein pointed out, the second half of the second oscillation is concerned with lowering l9 from A, by a lowering of the right side of the plate, thus completing the cycle of operations.

What I claim is:--

1. A method of opening up an annular rayon filament cake which comprises exerting rolling pressure upon the entire cake substance progressively around its circumference in alternating directions, the pressure being initially applied gradually and during the rolling action.

2. A method of opening up a frustro-conical annular rayon filament cake, which comprises exerting rolling pressure upon the cake progressively for at least a full circumference in alternating directions and along a line constantly parallel to the axis of the cake.

3. A machine for opening up a frustro-conical annular rayon filament cake which comprises rolling members at least one of which is in conical form, means for causing pressure between the members, means for causing relative rolling movement between the members, and means for varying the relative angular position of the members during the rolling movement to cause the rolling pressure to progress substantially circumferentially around the cake.

4. A machine for rolling frustro-conical annular rayon filament aggregates which comprises a concave platen, a conical roll, means for swinging the roll back and forth across the platen, and means for oscillating the axis of the roll and for causing axial movement of the roll during its swinging movement.

5. A machine for rolling frustro-conical annular rayon filament aggregates which comprises a concave platen pivoted at one end, a conical roll, means for swinging the roll back and forth across the platen, means for oscillating the axis of the roll and for causing axial movement of the roll during its swinging movement, and means for oscillating the platen about its pivot to cause pressure and to permit aggregates to be interchanged upon the roll.

6. A machine for rolling frustro-conical annular rayon filament aggregates which comprises a concave platen, a pair of arms pivoted for swinging movement, means for oscillating said arms individually through different arcs, a spindle, a conical cake-carrying roll carried by the spindle in said arms for free rotation therein and for angular displacement as required by the differential movement between the arms, a roll carried by one of the arms, a cam secured adjacent the platen and shaped to cause axial movement of the spindle, so as to cause the roll to follow the cake in its rolling movement, and means for moving the platen toward and from the roll.

7. A machine for rolling frusto-conical annular rayon filament aggregates which comprises a platen, a conical roll, and means for moving the roll back and forth over the platen in a path following substantially the true rolling path of the aggregate.

8. A machine for rolling frusto-conical annular rayon filament aggregates which comprises a platen, a conical roll, means for moving the roll back and forth over the platen in a path following substantially the true rolling path of the aggregate, and means for causing progressively increasing yielding pressure between the roll and the platen.

9. A method of opening up an annular rayon filament cake which comprises exerting rolling pressure upon the entire cake substance progressively in one direction, stopping the rotation before the wave of material set up by said rolling pressure has pressed into permanently distorted form, and then reversing the direction of the rolling pressure to remove the distortion caused by the rolling pressure in the first direction.

THOMAS McCONNELL.

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