US2068032A - Process and apparatus for the manufacture of rayon - Google Patents

Description

Jan.. 19, 1937. Q w, BRYANT' 2,068,032

PROCESS AND APPARATUS FOR THE MANUFACTURE OF RAYON` Filed March 27, 1955 7% 1 4 Sheets-Sheet 1 Jan. 19, 1937. .1' G.w. BRYANT v 2,068,032

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PROCESS AND APPARATUS FOR THE MANUFACTURE OF RAYON Filed March 27, 1935 y4 ShleetS-Sheet -5 INVENTOR ATTORNEYS G.w. BRYANT 2,068,032v PROCSS APPARATUS FOR THE MANUFACTURE OF RAYON Jan. .19, 1937.

Filed MIOh 27, 1935 4 Sheets-Sheet 4 a w WZ 6. w, I 1 6 n@ u H muv M /V 1 |H.l.\ 5

Patented Jan.. 19, 1937 UNITED STATES :PATENT QFFICE PROCESS AND APPARATUS vFOR THE MANU- FACTURE 0F RAYON Application March 27, 1935, :SerialNa l13,200

11 Claims.

This invention relates to the manufacture 4of rayon orartificial silk, and particularly to a new and improved process and a-pparatus for manufacturing rayon yarn.

`My improved process includes a novel method of treating rayon in cake form, after the rayon yarn cakes have been washed or otherwise puriiied, to improve the dyeing and other qualities of the yarn, and particularly the dyeing properties of rayon fabric made therefrom. My improved apparatus includes a novel machine for treatment of a rayon yarn cake after it has been washed or otherwise purified or liquid or fluid treated, but before it is dried.

An object of the invention is to provide a method and apparatus for manufacturing rayon yarn which, when fabricated, results in-a rayon fabric having improved uniformity of dyeing properties. v

' Other objects of the invention are to provide a method and apparatus for manufacturing rayon yarn having improved uniformity of elasticity, crink-le, denier, strength and dyeing properties, the latter especially after fabrication of the yarn; to provide a rayon yarn cake in which, when dried, the yarn throughout the cake has a substantially uniform superficial elasticity or crinklek and to provide a substantially annular and undistorted rayon yarn cake in which the yarn is free to contract in a substantially uniform manner and to a substantially uniform de-Y gree throughout all parts of the'cake, during the drying operation.

Other objects of the invention will appear from the following description, and from the drawings and claims.

A result of my invention is to produce an improved rayon yarn, and a rayon yarn cake composed thereof, in which the yarn throughout the cake has a substantially uniform dye index, and possesses the important property of dyeing in a substantially uniform manner, not only before but, more particularly, after, fabrication of the yarn, and in which the rayon yarn has improved uniformity of elasticity, crinkle, wave,

and other desirable physical properties in addition to its improved'uniformity of dyeing quality. To the ends stated a substantially uniform supercial elasticity or crinkle or waviness, is imparted to the yarn in rall parts of the yarn cake and is thereafter preferably set or fixed in the yarn.

An advantage ofthe present invention is that, throughout the entire process, the yarn cake is maintained in substantially annular and undistorted form. f

VOther results and desirablefeatures rof my invention will appear from the following description.

In rthe vmanufacture of rayon in this country a process commonly employed is the centrifugal one, sometimes referred to as pot-spinning or bucket-spinning. As a result of this spinning process there is produced in the spinning pot or bucket, a cake of spunV and twisted rayon yarn or fibre. In the case of the viscose process, with reference to which I shall more particularly describe my invention, fthis cake yis composed partly ofthe twisted rayon fibres themselves, and partly of variouslsalts, acids and other impurities carried over by the fibres from the `coagulating spinning bath `through which the filaments are passed on their way 'to the spinning bucket, or resulting from decomposition of the viscose. In `order to complete the Vmanufacture of the rayonit is necessaryto ysubject the'spun Afibres to various purifying and drying treatments,l sometimes referred ltoas processing. In the viscose process, these treatments commonly include aging theiibre, then `washingto remove salts and other impurities, desulphuring, bleaching, further washing, soaping, hydroextracting, and finally drying the fibre or thread before Vit is wound into the 'form of acone or other package in which'it is to ybe sold, or from which it isto be fabricated. Dyeing is ordinarily performed after fabrication of the finished thread.

The present invention is applicable to,rand may be lused in connection with, the process and apparatus described in United States Patent No. 1,973,953, patented September 18, 1934 on application of Beirne Gordon, Jr.

VThe usual and conventional form and shape for a rayon yarn (sometimes called fibre or thread) cake, when it is spun, which shape is ordinarily retained lafter the cake is doffed from the spinning pot (sometimes called the box or bucket), is that of the hollow frustrum of a cone. So far as I know, such hollow frustro-conical yarn cakes (as illustrated, for example, in the vdrawings of the said Patent No. 1,973,953), are vthe type commonly spun in this country, although incertain foreign countries it has, from time to time, been proposed or attempted to spin a straight-walled orcylindrical (hollow) cake. Y Y Y In accord with my present invention, and in order to overcome Vthe foregoing and other diiculties, and to produce a rayon yarn susceptible of being fabricated into a rayon fabric having high uniformity of dyeing quality, and having the other desirable properties and qualities previously described, I prefer to proceed according to the following illustrative example:

I first spin a rayon yarn cake by suitable means (of which an example is described in the specification of the previously referred-to United States Patent No. 1,973,953), and then proceed to wash and otherwise purify and treat or process the spun yarn cake in the manner described and claimed in that patent. I have found that during this and the treatment subsequently to be described, it is desirable and helpful to have the yarn cake enclosed in an elastic fabric stocking or sleeve, in the manner described and claimed in United States Patent No. 2,002,481 to Beirne Gordon, Jr., and Harold J. V. Michel, patented May 21, 1935. After the yarn cake has been subjected to the desired purication and processing reatrnents, it is inserted in the larger end of a reducing member having the form of a reducing die or reducing tube. This member (or its internal bore formed by the ribs, tobe presently described), is tapered in such a manner as to reduce the diameter of a yarn cake forced therethrough, as hereafter described. The tube is, preferably, open at both ends, and, in the preferred embodiment of my invention, is provided, on its interior surface, with a series of inwardly projecting ribs or flutings. These ribs are arranged to radially indent or corrugate the yarn cake, and more particularly the outer surface thereof, in the desired manner hereafter described in greater detail, without buckling the cake or distorting it from its original substantially annular form. The yarn cake is then (as by means of a suitable plunger) forced through the tapered, fluted reducing tube, with the result that the cake is simultaneously reduced in diameter, and crimped or corrugated from its outer surface inwardly. The arrangement and proportions of the tube, its length, and the size, shape and taper of the internal ribs, are all coordinated in such a manner (as hereafter particularly illustrated) that corrugations or iiutings are introduce-d into the yarn cake from the outside inwardly. When the operation is completed, it is preferable that the corrugations are deepest in the outer layers of the yarn, and decrease in size and depth as they approach the inner wall of the yarn cake.

' corrugations, particularly in its outer surface.

The reduced-diameter, corrugated yarn cake, after being forced along the reducing tube, may be discharged from the smaller end of the tube, and is still annular in form, but is provided with It is then transferred to and placed in a centrifugal bucket or whizzer, of such diameter as justto receive the reduced-diameter cake. In making this transfer, use may be made of the collar hereafter described. In the whizzing apparatus the cake is subjected to the action of centrifugal force, during which operation it is not only maintained in substantially its original annular form, but even the yarn in the corrugations is thrown outwardly against the inner wall of the whizzing pot,

by the centrifugal force. Some degree'of hydroeXtraction is also accomplished, whereby a part of the liquid is extracted from the cake by the centrifugal force, and the subsequent drying operation is facilitated. The cake still retains, however, a co-nsiderable quantity of liquid, usually water, which must be removed by drying, commonly performed in a suitable oven. Before the cake is dried, the centrifugal action of the whizzer (centrifugal bucket) has almost completely eliminated the corrugations produced in the outer wall of the cake by the ribs of the reducing tube, changing the corrugations into sharp crimps or reverse bends. Throughout the process the cake is maintained undistorted and substantially annular in form. But because the diameter has been substantially reduced throughout the cake, the yarn in all parts of the cake is free to contract ina substantially uniform manner, and this is facilitated by the crimps remaining in the outer part of the cake after whizzing. A diiculty arising in previously suggested methods of yarn Vcake treatment and drying (namely that the yarn in the outer portion of the cake is subjected to undue tension upon drying, while the yarn in the inner portions of the cake is free to contract Without being subjected toundue tension, thus producing a yarn having non-uniform crinkle, wave, superficial elasticity and other properties), is thus overcome by my invention, according to which the yarn cake is maintained in its annular shape and form before and during drying. Thus when shinkage subsequently occurs in the drying operation, there are no hard spots or other non-uniform sections in the yarn, which is sometimes the case when the yarn is pulled tightly across the outwardly extending portions of a deformed, distorted or flattened yarn cake. There thus results, from the use of my invention, a rayon yarn having high uniformity of superficial elasticity, wave and crinkle, as well as other desirable physical properties, and which, upon fabrication, produces a rayon fabric which may be dyed with improved uniformity and evenness, is substantially free from variations in color or shade, and is not subject to dyeing streaks or abrupt changes in appearance.

I shall now describe, by way of illustration, what is at present the preferred form of my invention and method of practicing the same (being the best form of the method and apparatus now known to me) in greater detail in connection with the accompanying drawings, in which:

Fig. l is a side elevation, partly in section, of the apparatus;

Fig. 2 is an end view, in elevation, of the apparatus;

Fig. 3 is a detailed sectional view of the dielike member or reducing tube with the plunger and a yarn cake therein;

Fig. 4 is a top plan view of the reducing die member shown in Fig. 3;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 3;

Figs. 6 and 7 are, respectively, a plan View and an elevation, the latter partly in section, of a yarn cake after it is spun but before it is passed through the reducing die;

Fig. 8 is a plan view, diagrammatic in nature, of the yarn cake after it has passed through and emerged from the reducing tube;

Fig. 9 is a diagrammatic plan view of the yarn cake after it has been centrifugally treated;

Fig. 10 is an elevation, partly in section, of a suitable forni of centrifuging apparatus, for centrifugal treatment of the yarn cake after it has emerged from the reducing die;

Fig. Il shows a modification of the apparatus, partly in section, in which the plunger is operated by a compressed air ram; and

Fig. 12 is a detailed View, partly in section, of the air ram mechanism.

Referring now more particularly to Figures l and 2, the cake reducing tube or die-like member, I8, is shown arranged .in vertical position, and provided with top and bottom openings, ilzlla and Mib. This die member is, lof course, lhollow or tubular inform, and is provided'withr ribs ll, upon its inner face, and .projecting radially inward from the .face -of the tube. 'I'he whole die member may conveniently be formed of a casting of brass, bronze or steel,.polished.on its inner face, and chromium ypla-ted to give 'a .smoothinish and hard wearing surface.

The member t8 is supported on a frame or base l 2, above which is arranged a suitable superstructure or framework i3. Aixed to .the .latter are an upper and-a lower guide'member, I 4.and l5, respectively,fin which is journaled the vertical rodV IB, attached at itslowerend to the plunger il. The latter iis arrangedin the form of a spider, with radially extending .fingers i8 .(see Figures 3 and 4). The plunger and fingers are so proportioned as to lit-between the ribs `Il of the reducing tube, so that the plunger is free to pass to the bottom of the tube and eject the yarn cake therefrom.

For actuating the plunger Il there is provided a lever i9 hinged at 20 to the bracket 2| and provided with a slotted fork 22. this fork receive and engage the pin 23 passing transversely through lthe Vertical rod I upon which the plunger is carried. A handle 24 may be provided at the outer end of the lever I9 and in addition, if'desired, a counterweight, 2.5, suitably arranged upon La cord, .26, running over pulleys, 21.

In Figure l the reducing tube is shown in sectionrwith a yarn cake 28 forced part way through the tube.

Referring Vnow lmore particularly 4to Figures 3, 4 and 5, the details of lthe die member I0 are shown, ,together with cross-sectional views (see Figures 3 andv 5) of a yarn cake -28 `in progress therethrough. The initial position `of the yarn cake is shown by the dottedlines 29, the dimensions of the reducing tube, at vthe inlet aperture ma., being such that a spun yarncake is received and held therein in a position to permit entryo'f the plunger. Thecake may be inserted in the reducing tube either small end first or large end nrst, depending, in part, upon the degree of axial compression desired. Discharge ofthe cake from the lower end of the tubeis facilitated'by inserting the cake large end down.

Upon application of axial compression to the cake, by means of the plunger l1, the cake is forced downwardlyand subjected to .simultaneous compression in the direction of its axisand radial indentation by the .action `of .the ribs l I. If vdesired, the lower portion of the ribs Il maybe somewhat relieved for a few inches fromthe bottom, as at l la, in order to permit somewhat .freer passage and ejection of the yarn cake.

Figure 4 shows a plan view of .thereducing die It, with its co-operating plunger l1; .and in Figure 5 there is shown, in horizontal.cross-section, the die I8 and a yarn cake 28 in process-of simultaneous radial indentation and axial compression, the cake being in the position shown by the full llines in Figure 3.

After' the yarn cake has been ejected 'from .the lower end of the reducing tube I0, it is transferred to the centrifuging pot or whizzer shown in Figure 10. This vpart of the apparatus may suitably include an electric motor 3D vencased in a suitable protective hood 3|, as illustrated. The motor isprovided with a vertical shaft 32,r having at its upper end a vertical spindle `33, uponwhich Theslots v220i in there is fitted .an adaptor member 34, fitting into a suitable bushing v35. The .latter is integral with :the .base 36 of the centrifugal whizzing pot or whizzer 3l. The construction of the adaptor 34, and its cooperating bushing 35, may suitably be that described and claimed in United States Letters Patent No. 1,948,834 .to Walter C. Volk, patented February 27, ,1934. The whizzing pot 3l is vprovided with anapeltured cover 38, heldin place by an expanding bent wire spring member 39, arranged to snap into the groove 48 provided for the purpose, thus-locking the cover into place during whizzing of the cake. Due 'to the fact that liquid is thrown off'ffrom the cake during the whizzing operation,

the .whole apparatus is preferably encased in a boxerr other suitable enclosure Lil, provided with ahinged lid 42, and a drain channel 53, through which .liquid extracted from the cake may run off and be discharged.

`The centrifuge pot 3l is circular in plan and in vhorizontal cross-section, and its interior diameter is preferably such that the yarn cake, after emerging from the reducing die, and upon being placed in the centrifuge pot, makes close Contact with the latter, at the outer surface dfi of the cake. When it emerges from the die, the cake is substantially parallel-sided, andthe centrifuge pot may, also, have parallel walls. However, a 'slight taper facilitates introduction and removal of the cake. The action of the centrif ugal'foroeis such that during the whizzing operation the yarn in the outer portions of the cake, even viin the radial indentations it (see Figure 8), is forced'as much as possible` into contact with the inner wall of the whizzing pot. Thus the yarn in the indentations '45 vis thrown outwardly against the wall of thepot, but, since the periphery of -theyarn cake Y28, measuredr along its outer contour, and'including the radial indentations 45, issubstantially greater than the inner pe riphery of .the pot .3i (the yarn cake having been substantially reduced in diameter by its passage through the ydie-member Hl), the net ren sult 4of the centrifuging operation is to produce a yarn cake, still substantially annular in form but in which, due to the fact that the individual threads or yarn fibres are longer than the circumference of the `cake in which they lie, the threads have, throughoutthe cake, a desired and desirable crinkle or wavy structure, as heretofore described. This crinkle or wave permits the yarn to contract with substantial uniformity when dried, in cake form, after the centrifuging is-completed and theexcess crinkle, not taken up by contraction, is set in the yarn, as hereafter describe-d. The resulting yarn has been found to have improved uniformity vof dyeing quality, particularly when fabric made therefrom is dyed subsequent to fabrication.

The form of the cake, in pian View, after completion of the .centrifuging operation, is shown diagrammatically in Figure 9.

The operation ofthe apparatus is, briefly, as

follows:

The rayon yarn cake 28,-after having been spunin .a centrifugal spinning bucket, is removed therefrom and Venclosed inan elastic fabric pro tecting stocking dl `(see Figures '7 and lo). It is then suitably processed and purified, by washing and otherwise', preferably as described in United States Letters. Patent No. 1,978,953, previously referred to. After such processing or purification treatment,` the cake is transferred tothe reducing die, i8, where it is inserted in the mouth thereof, la. By operation of the plunger l1, by the mechanism described, the cake is forced through the reducing die. Upon removal therefrom, at th-e outlet lb, the reduced-diameter cake, now radially indented and axially'compressed, is transferred to the centrifuging apparatus shown in Figure 10, where it is centrifugally treated. It is then removed and dried, preferably in an oven, after which the fabric covering l1 may be turned back from the cake and the yarn Wound into a cone or other suitable package for sale or fabrication.

Figures 6, 7, 8 and 9 illustrate, in somewhat diagrammatic manner, the size and configuration of the yarn cake at different stages of the process. It will be observed that the yarn cake, throughout the operations, retains its generally annular form and configuration,but that it is substantially reduced in diameter by passage through the die IU and that, as a result of the process, the cake has had artificial crimps or corrugations introduced therein, more particularly in the outer portions thereof, and, in general, decreasing in amplitude from the outside toward the inside of the cake. Since the crinkle or Wave normally tending to occur during the drying of the cake is more pronounced at and near the inner surface thereof, and is much less or substantially non-existent at the `outer surface of the cake, it will be seen that the artificially-introduced crinkle, decreasing from the outside inwardly, tends to compensate the normally occurring crinkle, decreasing from the inside outwardly, with the result that, after drying, there is a substantially uniform degree of crinkle and wave in the yarn in all parts of the cake.

It is to be noted that it is not necessary, in order to practice my invention with success, that the crinkled yarn from the inside and outside of the cake should be identical in appearance, as regards the shape, depth, size and frequency of the crinkles; it is, in general, sufficient if the yarn from the inside, outside, and all intermediate portions, of the cake possesses substantially or approximately the same amount or degree of crinkle, or has substantially the same proportion of its length occupied thereby.

In the case of a yarn cake spun in a spinning bucket of the customary approximately six-inch diameter, the following approximate dimensions, given by way of illustration, have been found to be satisfactory in commercial use, within the limits of commercial tolerance:

For the top outside diameter of the cake before it is passed through the reducing die, six and one-eighth inches; for the bottom outside diameter of the cake before it is passed through the reducing die, ve and thirteen-sixteenths inches; for the height of the cake before it is passed through the reducing die, three and onefourth inches. The thickness of the wall of the cake may be about three-quarters of an inch. For the outside diameter of the cake after passing through the reducing die, five and sevensixteenths inches; for the top inside diameter of the Whzzer pot 31, five and one-half inches. The difference permits the use of the Celluloid collar hereafter described. For the top outside diameter of the cake after centrifuging in the whizzing pot, five and seven-sixteenths inches; for the height of the cake after passage through the reducing die three and one-eighth inches. A suitable overall height of the reducing die is about twenty-six inches with a topl inside diameter, inside the ribs Il, of six and one-quarter inches, and a bottom inside diameter, inside the ribs Il, of three and fteen-sixteenths inches. The latter may be relieved about one-eighth of an inch, for a distance of about three inches from the bottom, to facilitate passage of the cake.

In drying a yarn cake of the approximate dimensions given, there ordinarily occurs a substantial shrinkage in the yarn, which may be of the order of as much as six per cent of its length, under the conditions herein stated. An important feature of my invention is that it may be so carried out as to permit such shrinkage to occur, in the drying of the yarn (subsequent to the centrifugal extraction of liquid therefrom), without subjecting the yarn to the tension and stretching which might take place if my invention were not employed. When my invention is not employed, and it is attempted to dry the yarn in cake form, it may happen that the yarn at or nearv the outside of the cake is subjected to considerable tension because of the shrinkage which occurs in drying, and such tension produces, or tends to produce, an undesirable alteration in the structure and physical properties of the yarn, resulting in non-uniformity of dyeing quality. Many previous attempts to overcome this diiiiculty due to shrinkage have proven unsuccessful, and have resulted in hard spots or straight sections in the yarn, due to non-uniformity of shrinkage and tension during drying. My invention, however, overcomes this as Well as the other difficulties previously mentioned.

For the reasons just stated, it is desirable that the reduction in diameter of the yarn cake, by passing it through the reducing die as heretofore described, should be at least sufficient to allow for the shrinkage of the yarn which occurs during the drying thereof. Such is, in fact, the case, with the figures and dimensions given above; the yarn cake is suiciently reduced in diameter by the reducing operation, and the centrifuge pot is sumciently less in diameter than the spinning pot, so that the crimps or Waves produced in the yarn comprise (in the preferred embodiment of my invention) at least as great, and preferably somewhat greater, a percentage of the length of the yarn as the yarn thereafter contracts during drying; that is, in the example given above, the crinkles and Waves occupy atleast, and preferably more than, about six per cent of the length of the yarn. Thus the crimps and waves comprise at least a sufficient amount of the yarn to allow for the shrinkage which occurs upon drying, and there is preferably a substantial excess in the crinkles. over and above what is taken up by shrinkage in drying, so that the finally purified and dried yarn, after shrinking to its fullest extent, is substantially uniformly crinkled and waved, has a substantially uniform extensibility and elasticity, and has a substantially uniform percentage of its length taken up by crinkles and waves, in all parts of the yarn cake. Thus yarn from all parts of the completed yarnA cake has substantial uniformity of the properties stated. Such is the preferred method of practicing my invention, and is the result of the figures and dimensions herein given by way of example.

A further advantage of my invention is that, in forcing the yarn cake through the reducing die member or tube, l (see Figure 3), the cake is subjected to simultaneous radial and axial compose the yarn threads beneath. It is also shown,

pression. The ribs` 'I I not only make radial indentations in the yarn cake, but the resistance is such that the plunger I1, in forcing the cake through the die, exerts a substantial axial compressional force on the top of the cake, and the height of the cake is consequently somewhat reduced. By reference to Figure 7 it will be seen that the cake is built up fromv a series of crisscrossed threads, due to the vertical reciprocating motion of the guide funnel during spinning. This gives to the cake a so-called diamond structure where the successive layers of thread cross at a slight angle, as illustrated in the upper righthand part of Figure 7. Now, the vertical compression of the cake, and its consequent reduction in height, tends to fiatten the diamonds With the result that each convolution of yarn lies in a more nearly horizontal plane. Hence each given length of yarn occupies a shorter path in the cake, and has, consequently, a little greater freedom to contract upon drying. Thus by vertical compression of the cake, simultaneously with its radial compression, the yarn is given increased freedom of shrinkage during drying, and lessgradial compression is necessary than if the vertical compression were not also effected.

In order to facilitate introduction of thereduced cake, 28, into the whizzing pot 31, and removal therefromI have found that it is often desirable toemploy a Celluloid collar 49, around the cake. Such a collar 46 is shown in Figure 10. It may be perforated to permit escape of liquid extracted from the cake during the centrifugal process. However, such perforations are not essential, since the liquid may escapeat the top o-f the collar 46, and around the edges of the cover 38. Y VThecelluloid collar 46 performs the dual function of acting like a ,shoehorn in facilitating insertion of the cake, Figure'B, into the whizzing pot 31, as shown in Figure 10, and also facilitating the removal of the cake after it has been subjected to the centrifugal force. When such a Celluloid collar 46 is employed, the inner diameter of thecentrifugal pot 31 should be sufficiently greater than the outer diameter of the reduceddiameter cake to allow for the insertion of the collar. This is indicated in the measurements given above.

In connection with the removal of the cake from the pot after it has been centrifuged, I have observed that, in the absence of a removable collar about the cake, such as 46, it may be difficult or impossible to remove the cake from the pot, indicating the substantial absence of internal strain in the'yarn cake, after the centrifugal operation. Such absence of strain or tension in the cake, after the whizzing is completed (when the cake has previously been reduced in diameter in accord with my invention) is another advantage arising from theuse of my invention, because I have observed that, in the ordinary centrifugal treatment of a yarn cake, when my invention is not employed, the cake tends to shrink away from the walls of the centrifugal pot as soon as the latter is stopped, indicating that the fibres are under tension during the centrifugal operation.

Throughout the process, from the time the yarn cake is first spun until the centrifuging is completed and the cake is dried, I have found that it isdesirable to have the cake encased in an elastic fabric stocking or sleeve, as already described. Such av protective fabric covering is indicated, diagrammatically, at 41`in Figure'l, whereit is shown' partially broken away toexinsection,fin Figure 10, and is shown or indicated inr the other gures.

Figures 11 and 12 show a modification of the apparatus in which the plunger is operated by an air ram under control of a suitable valve.

f In Figure 11 there is shown aside elevation of the apparatus with the air ram operating mechanism,` and Figure' 12l shows an end` view, in elevation, of the apparatus, partly in section, showing the details of' the air ram and its control valve and pipes:

Referring to Figure'12, the cake reducing tube or die-like member I8, is shown supported on the frame or base- I2. Above the cake reducing tube I0, and attachedthereto by suitable means, is a bracketl 48 provided with an air passage 58.

Intothe' to'p of the bracket 48, there is screwthreaded acylinder 49, and over the top of this cylinder 49, there is screw-threaded a cap 59, provided'with an air passage 59. At the top and bottom; of the cylinder, 49, there are provided suitabln-iV gaskets 54. Apiston 5I is disposed in this cylinder 49 and is attached to the top of a vertical rod 52; andheldI there securely by means of a nut 53. To the lower end of the vertical rod 52, there is attachedA the plunger I1, arranged in theKV forrnofy aspider as described hereinabove.

On' theunder side of the bracket 48, a packing gland 55-, with a suitable packing 55a, is arranged for the vertically reciprocating rod 52. On the inward sides of the bracket 48, there are provided a pair of bosses 56, having slots or grooves, 51, toY actas aguide .for the plunger I1; these slotsor grooves are preferably extensions of certain of the grooves provided by the ribbed interior ofthe tubevIU. A

A pipe line 6-0 connects with the air passages 58 and 5,9, and is provided withneedle valves 6I; preferably two of such needle valves are included, one for each of the air passages as shown. Intermediate-'the needle valves the pipe line 60 contains a fourjway valve 62, which has a port 92a connecteitovk the branch of the pipe line 60 leading to the air passage 58, another port B2b connectedtothe branch of the pipe line 60 leadingfto the air passage 59, another port connected with a compressed air supply pipe line 63, and arrexhaust porth65- This four way valve is of therusual construction, operated by alever 64, and arrangeduso that in its first position port 62h is connected With-fthe s upply line 63 and port 62al with the exhaust port 65, and in its second position poiftn62b vis connected with the exhaust port 65 andport'62a with the supply line 63.

'Iheoperationof this apparatus is as follows: The plunger I1 (and the connecting rod 52) is in it'sllgplJQI pmosit'im, as shown; a yarn cake is inserted"throughueither of the open sides of the bracket 48, below the plunger, and is dropped into the reducing tube III, as described hereinabove. Witlf the needle valves suitably opened and the four way Valve 62in, its first position, compressed air is transmitted from the supply line 93, through the'four way valve, port 62h, the upper branch of line` 6D' and its needle valve 6I, and thepassage 59, into the top of the cylinder 49, and forces'down the piston 5I, its connecting rod 52A and the plunger I1. This downward movement of the' plunger forces the yarn cake through the tube I8, in the manner previously 4described in `reference to Figures 1 to 8. During itsI downward stroke, the plunger is guidedby the slots orgrooves" 51, and the dead air inthe cylinder 49 below `the piston 5I is 75 forced out by the latter and exhausted through the air passage 58, the lower branch of line 60 and its needle valve 6|, port 62a, the four Way valve, and the exhaust port 65 to the atmosphere.

As will now be understood, the lever 64 can then be shifted or reversed to its second position, whereupon compressed air is admitted through port 62a, and the passage 58 into the lower end of the cylinder 49, and the piston 5| is thereby forced up to its original position, together with its connecting rod 52 and the plunger I1. On this upward stroke the dead air above the piston is at the same time forced out and exhausted through the passage 59, port 62h and the exhaust port 65.

The apparatus is then ready for insertion of another yarn cake and for operation thereon, carried out in the same manner, and initiated by shifting or returning the lever 64 to its first position, as explained hereinabove. As will also be understood, the speed of operation of the plunger can be controlled by the needle valves El, which are adjusted to regulate the amount of air admitted to and exhausted from the cylinder 49.

The process and apparatus herein specifically illustrated and described are the best embodiments of my invention now known to me, but it is to be understood that the invention is not necessarily or specifically limited thereto, but may be carried out in other Ways Without departing from its spirit, and within the scope of the following claims.

I claim:

1. Apparatus for use in the manufacture of rayon, comprising, in combination, a die-like receptacle having upon its interior surface a plurality of inwardly projecting tapered ribs, the mouth of said receptacle being of such size and shape as to receive and accommodate a rayon yarn cake, and the taper, configuration and arrangement of said ribs being such as to compress said cake radially, upon forcing the cake into the receptacle; and means for forcing a rayon yarn cake along said receptacle to subject the cake to radial compression.

2. Apparatus for use in the manufacture of rayon yarn, comprising, in combination, a tubular receptacle, substantially circular in crosssection; a plurality of spaced and tapered ribs projecting radially inward from the interior face of said receptacle; a mouth for said receptacle, of size and shape adapted to receive a rayon yarn cake; the form, size, shape, configuration and taper of said ribs being coordinated so as radially to compress a yarn cake forced along said receptacle; a plunger cooperating with said tubular receptacle and adapted to force a yarn cake into and along the same; and cooperating means for actuating said plunger.

3. Apparatus for use in the manufacture of rayon, comprising, in combination, a die-like tubular receptacle, substantially circular in cross section; a plurality of spaced, tapered ribs projecting radially inward from the interior Wall of said receptacle; an opening in the larger end of said receptacle of such size and shape as to receive a rayon yarn cake; the form, size, shape, configuration and taper of said ribs being such as radially to compress a rayon yarn cake, and simultaneously to introduce corrugations therein, when the yarn cake is forced along said receptacle; a plunger-like member cooperating with said die-like receptacle and adapted to force a yarn cake through the same; and cooperating means for actuating said plunger member, said means comprising a cylinder, a piston arranged for movement therein, means connecting saidpiston with said plunger member for advance and retraction of the plunger in accord with the motion of the piston, means for admitting fluid, under pressure, upony one side of said piston to advance the plunger and force the yarn cake along said receptacle, and means for admitting fluid, under pressure, upon the opposite side of said piston to retract the plunger.

4. In an apparatus for use in the manufacture of rayon, the combination of a die-like member having a converging internal bore of cross-sectional conguration such that it is adapted to engage the outer surface of a rayon yarn cake and reduce the diameter of the cake as it is forced along said die member, and cooperating means for forcing a rayon yarn cake along said converging bore.

5. In a machine for use in the manufacture of rayon, in combination, a die-like member having converging internal ribs and a plunger for forcing a yarn cake along said die-like member.

6. In a process of manufacturing rayon yarn, the combination of steps which comprises first spinning a rayon yarn cake by the centrifugal spinning method, then treating the cake to purify the yarn While substantially maintaining the original form of the cake, indenting the cake at its outer periphery While subjecting it to simultaneous radial and axial compression, and then drying the cake.

7. In a process of manufacturing rayon yarn, the combination of steps which comprises first spinning a rayon yarn cake by the centrifugal spinning method, then treating the cake to purify the yarn while substantially maintaining the original form of the cake, substantially reducing the diameter of the cake by subjecting it to simultaneous radial and axial compression, centrifuging the reduced-diameter cake, and then drying the yarn.

8. A process of manufacturing rayon comprising first spinning an annular rayon yarn cake by the centrifugal spinning system; then treating the spun cake to free the yarn from impurities, while maintaining the annular form of the yarn cake; then radially indenting the cake at a plurality of spaced points about its periphery while still maintaining the annular form of the cake but subjecting it to simultaneous radial and axial compression; centrifuging the cake to convert the radial indentations into crinkles in the yarn; and drying the yarn in cake form.

9. In the manufacture of rayon by the centrifugal spinning method, the process of manufacturing rayon yarn adapted for fabrication, before being dyed, into rayon fabric susceptible of being dyed with high uniformity, which comprises, in combination, the steps of first spinning a hollow frustro-conical rayon yarn cake, substantially annular in cross-section, by the centrifugal spinning method; then treating the cake to free the yarn from impurities, while maintaining the annular form of the cake; substantially reducing the diameter of the cake while subjecting it to compression in the direction of its axis and simultaneously introducing radial indentations therein, without substantially altering the annular form of the cake; forcing excess liquid out of the cake; and further drying the yarn.

10. The process of manufacturing rayon yarn adapted for fabrication, before being dyed, into 75 rayon fabric having substantial uniformity of dyeing properties even when the dyed fabric includes yarn from a plurality of yarn cakes, which comprises the steps of first spinning a substantially annular rayon yarn cake by the centrifugal spinning system; then treating the spun cake to free the yarn from impurities, while maintaining the substantially annular form of the cake; and then, Without buckling the cake or materially distorting or deforming it from its original substantially annular form, substantially reducing the diameter thereof While simultaneously applying axial compression thereto; centrifuging the reduced-diameter cake; and then drying the same, all While maintaining the original substantially annular form of the cake, and Without any material deformation thereof.

11. The process of manufacturing rayon which comprises rst spinning a substantially annular rayon yarn cake by the centrifugal spinning systern; then treating the spun cake to free the yarn from impurities, While maintaining the substantially annular form of the cake; reducing the diameter of the cake by an amount sufficient to permit subsequent drying of the yarn in the cake without subjecting the yarn to substantial tension due to shrinkage occurring during drying, While simultaneously applying axial compression to the yarn cake; and drying the yarn While still contained in the reduced-diameter cake.

GEORGE WILLARD BRYANT.

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