US2302792A - Apparatus for use in the manufacture of rayon - Google Patents

Description

Nov. 24, 1942; o 'fz 2,302,792

APPARATUS FOR USE IN THE MANUFACTURE OF RAYON Filed April 24, 1941 lllI IIIIIUIH I Jdzz'az) 1 11%?! -tendant difficulties. fort has been directed toward providing satisfac- -tory pieces'of apparatus and systems of opera- Patented Nov. 24, 1942 UNITED sTATEs' PATENT OFFICE APPARATUS FOR; USE IN THE MANUFAC- TUBE OF RAYON Adrian J. L. Moritz, Enka, N. 0., assignor to American Enka Corporation, Enka,.N. 0., a corporation of Delaware Application April 24, 1941, Serial No. 390,211

8 Claims. (01. 34-153) This invention relates to the continuous spinning of yarns of synthetic. origin and is more particularly concerned with a thread-storage, thread-advancing device employed incident to the practice of such a method for the manufacture of rayon.

The rayon spinning art, at its present state of development, includes three commercially acceptable methods of manufacturing threads of synthetic origin; pot spinning, bobbin spinning and continuous spinning. The first two of these have reached a high state of development and are at present widely utilized in the commercial production of yarns of synthetic origin. On the other hand, continuous spinning has not yet enjoyed wide-spread commercial acceptance.

It is apparent that continuous spinnin is theoretically the most satisfactory way of producing rayon yarn, because of the elimination of various intermediate winding operations and their at- As a consequence, much eftion with a view to rendering continuous spinning commercially feasible and to make available its inherent operating economies, as well as to further the production of yarn of high uniformity and superior quality.

advancing device used in continuous spinning is that it-be adaptable to the various after-treatments performed while the thread is passing thereover. In other words, the construction should be susceptible-to use with washing and desulphurizing baths or sprays and should be equally satisfactory. for drying and stretching operations. The control of the threads passing along the thread-storage, thread-advancing device should be complete and accurate so as to avoid tangles, matting or other difl'iculties requiring a temporary shut-down of one complete continuous spinning unit. It is also most important that the linear speed of the thread or yarn be as high as possible, since the volume of yarn treated per unit of time goes to the very essence of operating economy.

In the continuous spinning of rayon yarn, the

newly formed yarn is usually led directly from a spinning bath to a thread-storage, thread-advancing device around which the thread is passed in a series of generally helical coils. On this device an after-treating step, such as washing, is accomplished concurrently with the feeding of the thread across its-temporary support. After leaving the first thread-storage, threadadvancing device the yarn is generally led to another such device for a further after-treatment, such as desulphurizing, drying, stretching, etc. Finally, the finished thread issuing from the system is wound into some type of package fortwisting or in some instances for shipment to the consumer. Thus, inasmuch as continuous spinning ordinarily involves the leading of yarn successively to a number of thread-storage, thread-advancing devices, one important problem to be solved is quick and substantially automatic threading-up since manually winding coils on each of the various thread-storage,

thread-advancing devices used in an entire production plant would be so time-consuming as to 'counteractpractically all of the inherent advantages in continuous spinning. Another important requirement for a thread-storage, thread- The foregoing characteristics are of equal importance with respect to so-called semi-continuous spinning in which freshly extruded rayon thread is, wound on a thread-storage, threadadvancing device for one or more of the aftertreating operations and is then collected in Package form. 1

As the art stands at present, many of the foregoing difiiculties have been overcome. The apparatus developed for the purpose, however, is very complex and exceedingly costly to install. The simpler type of apparatus are generally susceptible to objection on one or more of the grounds set forth above; that is, the threadstorage, thread-advancing device is either not self-threading, not'adaptable for use with various types of treating liquid, or not operable at sufficient speed to insure manufacturing economies.

It is therefore an object of this invention to provide a thread-storage, thread-advancing device which will conform to the highest standards in self-threading characteristics, which is adaptable to all types of after-treatments, which may be operated at high speed and which, at the same time, is so economical to manufacture and install as to render it vastly less costly than any previously developed thread-storage, thread-advancing device which might be considered acceptable to the rayon industry from an operating standpoint.

According to this invention, it is contemplated that a single continuous thread may be efiicient- 1y subjected to all necessary after-treatments on tiously regardless of whether the unit is used in I a continuous spinning system or as an adjunct to bobbin or pot spinning.

Another object of this invention is to provide for the drying of threads of synthetic origin in a continuous manner with tension released so that the residual shrinkage in the dry yarn may be eliminated or greatly reduced.

Other objects and advantages of this invention will be apparent from the following detailed description thereof when considered in conjunction with the annexed drawing wherein:

Figure 1 is a view partially in side elevation and partially in section of a thread-storage, thread-advancing device constructed according to this invention showing thread in position thereon;

Figure 2 is a view in elevation of the end of the thread-storage, thread-advancing device of Figure 1 opposite the driving end thereof;

Figure 3 is a view in side elevation of a modified type of thread-storage, thread-advancing device constructed according to this invention, portions of the View being in section to illustrate heating means; and

Figure 4 is a view, partially in section,.taken along the line 44 of Figure 3,

Referring more particularly to Figures 1 and 2 of the drawing, it. will be seen that the threadstorage, thread-advancing device shown consists of a roller Ill and an arm II which together constitute a support for a continuous yarn or thread, and which may be relatively moved to cause the thread to feed axially of the device as a whole in a generally helical path. To this end, a shaft I2 is provided which projects axially from one end of roller 10. This shaft is a drive shaft for roller l and is keyed in a concentric position thereto in any suitable manner (not shown). The projecting portion of shaft I2 is supported for rotation in a bearing I3. The end of shaft [2 remote from roller I0 issuitably attached to a sprocket M for rotation therewith. Intermediate bearing 13 and roller III, a spider I5 surrounds shaft l2. This spider is freely rotatable in a concentric path about shaft I2 and serves as a support for its integral arm ll. Keyed to spider I5 is an additional sprocket Hi. It will be noted that inasmuch as spider I5 is mounted for rotation about shaft 12, arm I l and roller l0, when caused to rotate by actuation of their respective driving sprockets l6 and I4, will each move about a common-axis, i. e., the center.

of shaft l2. Furthermore, arm II and roller l0 .are independently driven through sprockets l6 and M, respectively, so that, by connecting the sprockets to different power sources, it is possible to drive arm H and. roller [0 at different rates of speed.

The source of power for sprockets l4 and i6 is not important to this invention except that some conventional means must be provided for driving the two' sprockets at different speeds. As will be hereinafter-explained in conjunction with the operation of this device, it is generally preferable that sprocket I6 be driven faster than roller l0 and/in the same direction.

Upon reference to Figure 2, it will be noted that the upper surface of arm I l is a threadcontacting surface and that such surface and the common axis of arm II and roller I0 0011- verge. It is this convergence which brings about the axial feeding of thread supported on the de-' vice. However, because of the convergence of the thread-contacting surface of arm H and the axis ofthe roller and the arm, a portion of the surface of roller I0 is frusto-conical in shape, the portion of greatest cross-section of roller l0 coinciding with the point of greatest convergence of the surface of arm H and the said axis. The purpose of so shaping roller I0 is to counteract the tendency toward a reduction of peripheral speed of the unit toward its outer end which would be normal to the use of a roller of uniform cross-section throughout its length. Such reduction in peripheral speed has, under some circumstances, been found detrimental causing the creation of slack in the thread thereby allowing convolutions thereof to mat when treated with a washing liquid or like spray. Of course, the apex angle controlling the conicity of roller Hi may be varied in such a way as to cause increases in peripheral speed as the thread coils approach the unsupported end of the device. In this case, stretching can be accomplished by use of the construction of the present invention.

The thread-storage, thread-advancing device shown in Figures 1 and 2 is intended for use as a unit of a continuous spinning machine containing a large number of such devices. In continuous spinning, the freshly spun filaments issuing from the coagulating bath are drawn therefrom directly to the first thread-storage, thread-advancing device on which after-treatment is commenced. Thereafter, the thread is led successively from thread-storage device to threadstorage device until after-treatment is complete. In initiating spinning, it is necessary, of course, to thread-up separately each thread-storage, thread-advancing unit of the system. According to the present invention, this is done by merely allowing the free end of the thread to fall across the top of the thread-storage, thread-advancing device somewhere adjacent its unsupported end, while the roller I0 is being driven in a take-up direction and arm II is driven in the same direction but at a greater rate of speed. (As an example of this, see Figure 2 in which arm II and roller ID are driven counterclockwise, the approach of thread being from the right as viewed from the unsupported end of the unit.)

, Because of the fact that the speed of rotation ment will be free f tangling because of the successive breaking loose of the thread end from roller In by action of arm' 1 I. Further yarn be- I ing continuously supplied at the supporetd end of the device, the unit will form additional coils and thread itself up until it assumes the appearance illustrated in Figure 1. The free end may be then led to the next unit which can be likewise threaded-up and so on until the entire machine is placed in operation,

The reason for the axial feeding of the thread -on the thread-storage, thread-advancing device is clear, for when a free end of thread is dropped on the unit there is some slack. The arm II engaging this material tends to carry the'same around the roller to form a loop. The loop so formed, and all succeeding loops or coils wound on the unit, are lifted off roller III at least once in the rotation thereof because of the relative end of the device, so as to go onto the threadcontacting surface of arm II at right angles thereto. As each coil falls back on roller I, therefore, it has been moved in an axial sense. After the free end of thread has been led away from the original thread-storage, thread-advancing device, the continuous thread continues to approach and .to leave in the manner indicated in Figure 2 and to follow the path indicated in Figure 1. It is evident that the amount of axial feeding accomplished by the arm I l is dependent upon two factors. As the angle of convergence with the axis of the device increases, the amount of slippage for every time a coil of thread is raised by the arm H will proportionately increase. Furthermore, if the number of times the thread is lifted per revolution of roller Ill is increased, the amount of axial feeding per revolution of roller II) will be proportionately increased. Thus, increasing the angle of convergence of the arm surface of the axis of the device and/or increasing the speed differences between arm H and.

roller I will have the effect of causing the coils to be spaced further apart. While the relative speeds of roller I0 and arm ll serve in part to control spacing, the combination of the two speeds will control the linear speed of the thread and consequently the amount of thread which .may pass over the roller per unit of time.

Although in the foregoing description reference is made to driving arm II at a speed in excess of that of roller'lO, it is evident that the axial feeding is caused by difference in relative speed between roller l0 and arm H.' Thus, if a speed difference exists, arm H may be driven either slower or faster than roller and the direction of movement is unimportant, the collection of the thread being determined by the direction of rotation of roller l0. While the above rather substantial variations are possible after the machine is threaded up and in operation, during threading up it is quite important to drive the arm and 'roller in the same direction, the arm operating at a speed in excess of that of the roller. This is to keep the free end of the thread from maintaining contact with the roller for a period .of time sufficient to form a serious tangle and so that the arm can catch the free end'of thread to form the first loop or coil.

' Although in the construction of Figures 1 and 2 only a single arm I I has been shown, it is evident that a plurality of arms may be employed so long as the thread is allowed at some point to contact roller Ill.

Upon referring to Figure 2, it will be noted that yarn passing onto the thread-storage, thread-advancing device in the direction of the arrow will be subjected to an intermittent pull when the portion of the device having the greatest radius is in pulling position; that is, when the arm is in the position shown in Figure 2. It has been found that any stretching incident to this action can be substantially counteracted by insuring that the length of yarn travel between its last point of support and the point of tangential contact with the device be'equal to at least two diameters of roller I0.

In the foregoing discussion, the thread-storage,

thread-advancing device of this invention has been described in its function as a unit of a continuous spinning machine. It is evident, however, that the invention is adaptable as an adjunct to pot spinning and bobbin spinning. In

this case, the freshly extruded filaments may be led directly from the spinning bath to await such as that shown in Figures 1 and 2 and a washing liquid may be applied to the thread in its passage thereover.

advancing device for desulphurizing or alternatively may be wound on a bobbin or laid up in cake form in a spinning pot. The resultant package can then be dried according to conventional practice. In the event the desulphurizing operation is performed while the thread is passing across a thread-storage, thread-advancing device, following that operation, a bobbin or pot collection can be effected. The advantage in this type of spinning, which has been characterized in theindustry as semi-continuous spinning, is that a: thorough regeneration of the thread and adequate washing thereof is insured before the preparation of a package, this resulting in the production of a thread of superior quality characterized by a high degree of uniformity throughout/its length.

The construction shown in Figures 3 and 4 of the drawing is similar in operation to the embodiment of the invention illustrated in Figures 1 and 2. A roller I! is provided having a shaft l8 attached thereto in the manner of shaft 12 to roller l0. Sprocket l9 corresponds in struc-- ture and function to sprocket M. A spider 2t, and a driving sprocket therefor 2|, also conform in construction to the similar parts of the apparatus shown in Figure 1. Spider 20, however, is provided with two arms 22 adapted to move concentrically about roller l1. Roller 11 is a hollow cylindrical one provided with a flared portion 23 at its unsupported end. This flared portion communicates with a drain arrangement 24 which serves to drain out a heating fluid which is supplied to the interior of the roller through roller I'I is'for a drying operation and during the drying of wet spun rayon, a certain amount of shrinkage occurs. Thus, if the cross-sectional area of the unit remained constant for the entire length thereof, the normal shrinkage incident to drying could not occur, but, on the contrary, undesirable tension would be a necessary incident to the axial feeding operation. As has been discussed above, a reduction in peripheral speed occurs as the free end of the device is approached. This may be controlled by the inclination of the arms 22 shown in Figure 3 so that reduction in cross-sectional area of the device may exactly correspond to the shrinkage brought about in the drying operation. Thus, properly. dried and shrunken yarn may be producedJn'i wholly continuous manner according to t Thereafter the thread may be led to another thread-storage, threadteachings of this invention. The threading up and feeding accomplished by the device of Figures 3 and 4 is similar to that previously described in conjunction with Figures 1 and 2.

Having now described the invention in its preferred forms, it is understood that variations and modifications may be made therein without departing from the spirit thereof, and it is therefore desired that the scope of this invention be limited only by the appended claims.

What is claimed is:

1. A thread-storage, thread-advancing device comprising, rotatable means defining an elon-' gated thread contacting surface, at least one arm independently rotatable about the surface of said means in a path concentric thereto, the thread contacting surface of said arm and the axis thereof converging, and means for driving said rotatable means and said arm at different speeds. 2. A thread-storage, thread-advancing device comprising, rotatable means defining an elongated thread contacting surface, an: arm independently rotatable about the surface of said means in a path concentric thereto, the thread contacting surface of said arm and the axis thereof converging, means for driving said rotatable means and said armat different speeds, and means for supporting said arm and said rotatable means from one end only of the device.

.3. A thread-storage, thread-advancing device comprising, a roller rotatable about an axis, an arm also rotatable about said axis, said arm being spaced from but overlying the thread contacting surface of said roller, the thread contacting surface of said arm and said axis converging, and independent means for driving said roller and said arm at different speeds to cause the same to move about said axis.

4. A thread-storage, thread-advancing device comprising, a roller rotatable about an axis, an arm also rotatable about said axis, said arm being spaced from but overlying the thread contacting surface of said roller, the thread contasting surface of said arm and said axis converging, independent means for driving said roller and said arm at different speeds to cause the same to move about said axis, and means for supporting said arm and said roller at the end of the device remote from the end of greatest convergence of the surface of said arm and said axis.

5. A thread-storage, thread-advancing device comprising, a roller having a frusto-conical thread contacting surface, a drive shaft extending axially from and supporting said roller for rotation, a spider mounted for rotation about said shaft, an arm extending from said spider and overlying the surface of said roller in spaced relation thereto, said arm including a thread contacting surface convergent toward the axis of rotation of the roller, means for driving said arm and said roller at different speeds, the roller increasing in diameter in the direction of the convergence of the surface of said arm and said axis, whereby to maintain a substantially constant peripheral speed of thread passing over the roller and arm when the roller is caused to rotate and the arm to move thereabout.

6. A thread-storage, thread-advancing device comprising, a roller having .a frusto-conical thread contacting surfaceLa supporting drive shaft extending axially from one end only of said roller, a spider mounted for independent rotationabout said shaft, at least one arm extending from said spider and overlying the surface of said roller in spaced relation thereto, said arm including a thread contacting surface convergent toward the axis of rotation of the roller, means for driving said spider and said drive shaft in the same direction at different speeds about their common axis, the roller in-- creasing in diameter in the direction of the convergence of the surface of said arm and said axis, whereby to maintain a constant peripheral speed of thread passing over the roller and arm when the roller is caused to rotate and the arm to move thereabout.

7. A thread-storage, thread-advancing device comprising, a cylindrical roller, a drive shaft supporting said roller for rotation about its axis, a spider mounted for independent rotation about said shaft, a plurality of arms extending from said spider over the surface of .said roller in spaced relation thereto, the thread contacting surface of said arms converging toward'the end of said roller remote from said shaft, means for heating said roller, and means for driving said spider and said shaft at different speeds, the convergence of said arms resulting in a progressive reduction in the periphery of the device in the direction of its feed, whereby free shrinkage of thread being dried thereon is permitted.

8. A thread-storage, thread-advancing device comprising, a cylindrical roller, a supporting drive shaft extending axially from one end only of said roller, a spider mounted for independent rotation about said shaft, a plurality of arms extending from said spider over the surface of said roller in spaced relation thereto, the thread contactin'g surface of said arms converging toward the end of said roller remote from said shaft, means for heating said roller, and means for driving said spider and said shaft at different speeds about their common axis, said heating means being applied from the end of the device remote from the axially extending shaft, the convergence of said arms resulting in a progressive reduction in the cross-sectional area of the device in the direction of its feed, whereby free shrinkage of thread being dried thereon is permitted.

. ADRIAN J. L. MORITZ.

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