US2646342A - Loosening rayon yarn packages by simultaneous soaking and deformation - Google Patents

Description

July 21, 1953 LOOSENING R C. D. VANDENBURGH AYON YARN PACKAGES BY SIMULTANEOUS SOAKING AND DEFORMATION Filed June 29, 1948 INVENTOR. (HA/9L ES 0. VANDENBURGH cakes. 1

Patented July 21 I LOOSENING RAYON YARN PACKAGES BY I SIMULTANEOUS SOAKING AND DEFOR- MATION Charles D. Yandenburgh, Ch'arles town, Md., as- Y 'signor to American Viscose-Corporation, Wilmington, Del., a corporation of Delaware Application June 29, 1948, Serial vNo."35,9'44

' 1' Claim. (Cl. 8'-1 55.'2)

This invention relates to an improved means and method for loosening orppening annular yarn and thread packages and, more particularly, to an improved'method of loosening or opening annular packages of regeneratedcellulose yarn or thread which lack an internal supporting core. I

In the manufacture of'regenerated' cellulose thread from viscose by the box or bucket spinning methodthe thread is collectedin an annular form or cake which is later subjected to various liquid treatments. The cake as collected is compact, and is not readily penetrated by the treating liquids and it is desirable, therefore,'to first loosen the layers of the cake to make it'm'ore permeable before ,passing itnthrough the liquid treating stages. j a V Various methods for loosening I rayon cakes have b'eenproposed. For example, it has been suggested'to bend the cake, at successive points around its periphery intermediate to striking of the cake againsta pressing surface. Again, it has been'sugge'sted to flatten the'cake by pounding. Also, it has been' proposed to stretch the cake manually by a pull applied to the opposite ends thereof.-

All such methods are damaging to the freshly formed regenerated cellulose, threads. If thecakes are bent or pulled and stretched manually, the threads are subjected to strains which are non-uniform and which harmfully affect the cake extending transversely of the surfaces, and rolling and advancing the cake in the direction of convergence of the surfaces while the cake is partially submerged in a liquidinert to the threads. Preferably, the cake is wrapped in a a porous, liquid permeable wrapper prior to being quality of the thread, especially the dyeing q'ual- I ity. Mechanical pounding exposes the freshly formed thread to the danger of breakingor-fraying.. V

The principal object of this invention is to pro vide an improvedmethod for loosening thread cakes comprising freshly formed regenerated cele lulose without damage to the thread. 'A further 5 object is to provide a method by which the cakes may be loosened and made readily permeable to treating liquids in a very short period of time.

Another object is to provide a method for loosening rayon cakes to produce a cake which is uniformly porous at all portions of its cross-section. An additional object of the invention is to provide an improved means for loosening rayon.

These and other objects of the invention are accomplished by feeding the rayon caketo be loosened between two surfaces arranged one above the other in converging relation and continuously travelling at different speeds and in 013- posite directions, or at different speeds in'the same direction, with the longitudinal axis of the of the belts is such that the lower half of the cake passing between themis immersed in the 7 liquid in trough 2. The level of the liquid may fed between the travelling surfaces.

The relative speeds of the moving surf-aces may surface, to insure that the cake moves progressively from the'feeding end to the discharge-end of the passageway provided between the belts, as

it is rolled thereb'etween V The invention 'is illustrated by the accompanying drawing in which the; single illustration'is an elevation of means for practicing a preferred-embodiment of the invention.

The apparatus shown comprises a trough- 2 containing water or other inert liquid to the level shown at 3. An endless belt 4, which may be of any suitable smooth, resilient, material which does not exert an abrasive action on the thread, such as leather; rubber, plastic, ortextile fabric, travels around the rollers 5 and 6 supported above the level of the ater in the trough, roller '6 being positively driven by any'suitab'lemeans. An endless belt 'l'similar to belt 4'travels inthedirection of divergence of the belts aroundthe' rollers 8 and 9 which are supported below the level'of the water, ,anddriven'from pulley ll by'belt [0 through pulley I2. The diameter of pulley I2 is twice the diameter of pulley I 'l on the drive shaft 16, and the surface of belt 4, between thebelts,

runs at a speed twice the speed of the surface of f so that the belt supported below the level of the liquid runs at the higher speed. The apparatus may be adapted to handle rayon cakes of any dimensions, by varying the distance between the belts. V

In the embodiment illustrated, the disposition be controlled so that only the portion' of the cake below the lower inner wall is immersed, or the level of the water may be just below the upper inner wall of the cake. Preferably, the lower half of the cake is submerged in the liquid, and in any event the upper inner wall of the cake is above the level of the liquid during the entire loosening operation. Any liquid inert to the thread may be used, and preferably the liquid is one which dissolves out crystalline substances'carried from the spinning bath and packed between the layers of the cake. The water or other liquid is maintained at the desired constantlevel by any suitable means such as the inlet pipe [4 and the overflow pipe, l5, and a constant circulation of the liquid in the trough is maintained in order to avoid accumulation of the acid dissolved out of the thread, which is generally formed by extrusion of viscose into an acid setting bath.

When a rayon cake is simultaneously rolled and advanced between the belts, while the cake is partially immersed in water, the layers of thread at all portions of the cross-section of the cake are uniformly loosened, and the cake withdrawn at the discharge end of the device is characterized by an increased porosity which is uniform at all portions of the cross-section. This uniform porosity of the loosened cake is important since it insures that all portions of the cake will be exposed equally to the treating liquids applied to the cake in subsequent operations.

During the loosening process, as shown in the drawing, the cake 13, provided with the liquidpermeable wrapper Him, is more or less flattened as it travels between the belts, and the dimen sions of the cake are altered, the diameter being decreased and the length (or height) being increased. For example, when a cake 7 x 6" is rolled and advanced between the belts having a length of 30", and spaced apart so that the surface between the belts converge from a distance between them of 7 /2" at the feeding end to a distance of 4"at the discharge end, the cake withdrawn at the converging ends of the belts, after a single passage between thebelts, has the dimensions 6" x 6 /2", i. e., the diameter is decreased by and the length is increased by The cake has markedly increased porosity as evidenced by the fact that the treating liquids could be passed through the cake at the rate of 1260 cc. per minute, which contrasts with a rate of 500 cc. per minute for a cake which had not been loosened in accordance with the invention.

The cake may be rolled and advanced between the belts more than once, with further loosening thereof, and decrease in diameter and increase in length, or the belts may be of, increased length to accomplish the same purpose, but generally a single passage of the cake between the belts having a length of about 30" is sufficient to loosen the layers of the cake and render the cake highly permeable to the treating liquids. The liquidtreated cakes do not comprise interior layers of thread which have not been adequately exposed to the treating liquids. The cakes are loosened 4 in a very short time, only a few minutes being required for the cake to be rolled and advanced between the belts and withdrawn in the loosened condition. The loosening operation therefore does not appreciably increase the time required to produce the final thread. The cakes may be fed continuously between the belts and withdrawn continuously at the discharge end, as they proceed to the usual liquid after-treating stage.

Outstanding advantages of the invention are that the cakes are uniformly loosened at all portions of their cross-section without subjecting the cake or the thread to forces tending to damage the quality of the thread. The rolling motion to which the cakes are subjected, as they are advanced in the direction of convergence of the belts while partially immersed in water, is harmless to the thread. Thread obtained from packages or cakes loosened in accordance with the invention, after-treated and finally washed with water, has been found to shrink uniformly during drying and, after drying, to have more uniform residual shrinkage capacities, which results in a more uniform dyeing of the thread.

Variations and modifications may be made in practicing the invention without departing from the spirit and scope thereof, and the invention is not to be limited except as defined in the appended claim.

I claim:

The method of loosening an annular wound package of rayon which has no internal supporting core which comprises continuously rolling the package with its axis extending generally horizontally through an aqueous liquid bath having a level between the opposed upper and lower portions of the inner wall of the package while progressively reducing the vertical diameter of the package by continuously pressing the package during the rolling across its entire width at diametrically opposite upper and lower peripheral areas between two juxtaposed, converging, smooth, and continuous surfaces.

CHARLES D. VANDENBURGH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 32,177 Brannan Apr. 30, 1861 999,499 Herzog Aug. 1, 1911 1,605,164 Brandwood Nov. 2, 1926 1,798,623 Obermaier Mar, 31, 1931 2,130,791 Dunham Sept. 20, 1938 2,343,916. Long Mar. 14, 1944 2,343,943 Thompson Mar. 14, 1944 FOREIGN PATENTS Number Country Date 363,064 Great Britain Dec. 17, 1931

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