US2886878A - Apparatus for treating a warp of threads - Google Patents

Description

May 19, 1959 KURD-JURGEN SCHULZE ,8

APPARATUS FOR TREATING A WARP OF THREADS 5 Filed April 30, 1957 INVENTOR.

KURD -JURGEN SCHUZZE BY WW 3 .744

ATTORNEY APPTUS non TREATWG A WARP or TADS Kurd-Jiirgen Schulze, @berbruch, Kries Heinsberg, Germany, assignor to American Enka Corporation, Erika, N.C., a corporation of Delaware Application April 313), 1957, Serial No. 656,122

Claims priority, application Germany May 3, 1956 6 Claims. (Cl. 28-48) This invention relates to a method and apparatus for treating continuously moving filamentary material of indefinite length. More particularly, the present invention relates to a method and apparatus for liquid aftertreating a warp of closely spaced parallel viscose rayon threads at a high rate of speed.

In todays competitive market, a quality yarn must be produced at the most economical cost. To meet this requirement the rayon industry is finding increased application of continuous spinning machines.

Many continuous machines and processes are known wherein artificial filaments of viscose rayon are produced by which a large number of threads are formed simultaneously and are conducted in a parallel path in the form of groups of threads through the coagulation and aftertreatment baths, and finally through drying devices. For example, in many of the conventional continuous systems, the treating liquids are contained in shallow troughs which the groups of threads travel horizontally between two rollers.

However, to operate economically the continuous machines should be adjusted to produce at a high production rate. Not only must the linear thread speed be relatively rapid, but the number of threads in the warp should also be increased to the maximum. Furthermore, this increased production must be accomplished without sacrificing the quality of the threads or subtracting from the elfect of the treating operation.

It is well known that treatment of threads of viscose is particularly dilficult at rapid rates. For example, the filament constituting the thread after extrusion and coagulation have a very different constitution as compared with the composition of finished thread and are in a plastic condition. While in this plastic condition or so-called gel state the thread may be stretched and disturbed to a reasonable amount. However, excessive stretching or disturbing of the thread will cause an inferior product to be produced. Also, the likelihood of filament breakage increases as more tension is applied to the threads.

As can be seen, increased tension ordinarily occurs when the rate of spinning is increased. This increased tension is caused by the drag exerted by the liquid of the bath through which the thread is traveling. In other words, as the rate of spinning and aftertreating are increased, the thread is subjected to an increased drag in the trough treatment process. Also, with increased velocities it is difiicult, if not impossible, to avoid a turbulent flow of the liquid within the treating troughs. This turbulence creates eddies and undersirable currents that cause the adjacent threads to run together or to form loops and thread entanglements. In any'event, it is exceedingly difiicult to insure uniformity of the thread properties at a high production rate with ordinary spinning methods. For example, when the linear velocity is increased to near meters per minute, the quality of the thread is notably reduced due to the undesirable flow conditions.

Attempts have been made to increase the rate of production of viscose rayon threads by the continuous system without the usual corresponding thread damage, etc. For example, in copending application Serial No. 361,782, filed June 15, 1953, now Patent No. 2,807,953, owned by the present assignee, there is described an ap paratus that minimizes the objectionable irregular counter current and crosscurrent flow of the liquid within the treating troughs. This improvement is achieved by the use of flow plates located inside the troughs. With these flow plates, it is possible to suppress satisfactorily the formation of turbulent flow with withdrawal speeds as high as 100 meters per minute. However, even higher treating speeds are desired than may be possible with the use of the plates.

Another method is known by which aftertreatment of groups of threads at relatively high withdrawal speed may be accomplished. This method comprises subjecting the threads to contact with a freely descending bath. By this process the threads are guided through liquid troughs having openings in the bottom with the threads passing vertically and downwardly through the openings. However, the washing and after-treating effect of this method is not particularly favorable; and, in addition, it is necessary constantly to pump the treatment liquid up into the containers positioned above the baths.

None of the foregoing is wholly satisfactory for aftertreatment of a warp of artificial filaments produced by the viscose process at a high rate of production.

Therefore, it is an object of the present invention to provide a method and apparatus for aftertreating a warp of viscose rayon threads through a series of suitable treatment baths at a relatively high linear speed.

Another object of the present invention is to provide a method of maintaining the parallel threads in a warp in close relationship to each other in order to treat a maximum number of threads of a warp of a given width.

A further object of the present invention is to provide a method of employing high treating speeds and yet avoiding the adverse eifects which ordinarily accompany such elevated speeds, such as liquid drag, thread tension, liquid eddies and undesirable currents, thread entanglement, and non-uniformity of physical properties.

A still further object is to accomplish the foregoing in a uniform and controllable manner.

These and other objects are accomplished by directing a warp of closely spaced parallel threads continuously around a freely rotatable drum partially emersed in a trough containing a treating liquid. After suitable wetting, the threads are withdrawn from the trough upwardly at an acute angle in close proximity to a flat supporting plate. As the threads transverse the plate, a stream of the treating liquid formed by the separation of the entrained liquid from the threads is maintained in countercurrent direction to that of the threads. The stream of liquid is kept at a reduced speed as compared with the thread speed. Also, the stream bridges the distance between said plate and thread. After passing over the plate for a predetermined distance the liquid is further separated from the threads and collected for return to the treating trough. Thereafter, the threads are directed through similar treating operations or to a suitable drying device after which the threads are taken up in a package form. The process of the present invention is conducted in a manner wherein the threads are fully treated during a process in which the tension on the threads is held at a low constant value and the disturbance to the closely-spaced threads is held to a minimum.

To further understand the present invention, reference is made to the accompanying drawing that is schematic and illustrates a Warp of threads being treated by the process of the present invention.

As seen in the drawing, the apparatus of the present invention briefly comprises a supporting plate which forms an acute angle with the treating bath surface. At the upper end of the supporting plate two or more deflecting plates are arranged substantially at a right angle and form parallel slots between the deflecting plates and between the supporting plate and the deflecting plate adjacent thereto. Two warp guiding means are arranged at the top and bottom ends of the supporting plate in such manner that the groups of threads traveling between them are in a plane parallel to the supporting plate and closely spaced from the latter. A driving means is provided to propel the work between the two guiding means.

Referring more specifically to the drawing, it is seen that numeral 1 designates a positively driven roller for propelling the warp of threads 6 from a prior and similar treating operation (not shown). The warp of threads 6 is guided around drum 2 which is freely rotatable and which is mounted so that it is about half emerged in the treating liquid 4 contained in trough 10.

As the warp 6 travels around drum 2 it comes into contact with the liquid 4. Due to the absorbency and movement of the threads, a considerable amount of liquid is absorbed and entrained therein during the passing of the warp 6 through the liquid 4.

A flat elongated supporting plate is mounted by suitable means and positioned at an acute angle with respect to the surface of the liquid 4. An end of said plate 5 extends into the liquid and is located adjacent to the bottom of drum 2. At the opposite end of plate 5 there is provided two deflecting plates represented by numeral 8. The deflecting plates 8 are substantially parallel to each other and normal to the supporting plate 5. The deflecting plates 8 are spaced apart and define slots between each other and between the supporting plate 5 and the deflecting plate 8 adjacent thereto. The top edges of deflecting plates 8 are slightly below the path of the thread travel.

Second drum 7, which is freely rotatable, is circumferentially grooved and together with drum 2 determines the path of the thread travel across the plates 5 and 8. Said drum 7 is preferably mounted within the collecting vessel 9. The grooves of drum 7 provide convenient spacing of the threads and tend to separate some of the excess liquid entrained in the warp 6.

The collecting vessel 9 arnasses the treating liquid which overflows over the top end of supporting plate 5 and which is separated from the threads and deflected by deflecting plates 8 into the vessel. Preferably, the length of plates 8 approximates the width of plate 5.

Roller 3 is similar to roller 1 and is used to propel the warp to a subsequent treating station or to drying devices.

In operation, the excess liquid which the threads pick up separates from the threads and forms a thin stream or film between the threads and supporting plate 5. The angle of inclination of the plates causes the stream of treating liquid to flow down the plate 5 while the forward movement of the threads tends to urge the liquid upwardly but to a lesser degree. Any liquid flowing over the elevated end of the plate may be collected.

It is very surprising that by the above-described process and apparatus one can produce threads of highly uniform physical properties at a high production. This is especially true since heretofore it was thought that the thread to be properly aftertreated had to remain completely emerged in the treating liquid for a considerably longer time than is necessary in the present invention.

Various modifications of the present invention are obvious to one skilled in the art. Far example, the discharge pipe of the collecting vessel 9 may provide a return directly to the container of the treating liquid as illustrated specifically herein. But it is seen that the liquid may be sent to another liquid receptacle and then recirculated for use in treating further lengths of filamentary material. Also, the liquid may be refreshed prior to each recirculation in a conventional manner. Furthermore, the collecting vessel 9 may be mounted within or without the treating liquid container.

Although the present invention has been described herein with reference to one treating operation, the invention also provides means for applying a number of treating liquids in succession to running lengths of threads. In other words, different treating liquids such as desulfurizing liquid, a bleaching solution, a solution for Washing, etc., may be applied to the warp of threads in sequence. Of course, additional liquid treating stages other than those enumerated above may be used, if de sired.

Also, as will be obvious, the present invention may be used for processing filamentary material during aftertreating of other fibers, such as cuprammonium yarns.

The invention will be further illustrated by the example that follows, which is to be construed as an embodiment of the invention and not a limitation thereon.

Example A plurality of continuous filament viscose rayon threads spun from a plurality of spinning points and coagulated in a conventional acid setting bath were gathered into a warp having closely spaced and parallel threads. The horizontal spacing of the threads was 3 mm. The threads were subjected to a hot water wash treatment while using the apparatus described in the present application. During the warp travel across the inclined supporting plate, the stream of liquid between the threads and the plate was maintained at a depth of about 1.5 mm. The linear speed of the threads during this washing operation was 156 m./min. The speed of stream down the plate was measured to be about 47 m./ min. Hence, the speed of the stream was about one-third of the thread speed. The threads were then completely aftertreated through other similar operations employing various conventional treating liquids and thereafter dried. The physical properties showed high uniformity and the thread compared favorably with, and in some instances was better than, threads produced by the conventional bath emersion method, which, of course, had to be operated at a greatly reduced speed with the threads being further spaced apart as compared with the present invention.

It is, of course, understood that various changes may be made in the apparatus and process above described without departing from the spirit of the invention as defined by the claims.

What is claimed is:

1. An apparatus for a liquid treatment of a Warp of closely spaced rapidly moving threads comprising an open trough for a treating liquid, a freely rotatable drum mounted within said trough and disposed in part below the normal liquid level, a vessel mounted over said trough for collecting and returning said liquid to said trough, a flat elongated plate disposed at an acute angle with respect to the liquid level and having one end extending below the liquid level and adjacent to the submerged portion of said drums with the opposite end thereof extending over said vessel, a second freely rotatable drum mounted over said vessel, means mounted within said vessel between said second drum and said plate for deflecting liquid downwardly into said vessel and a positively driven roller for propelling a warp of threads between the two said drums and in close proximity to said plate.

2. An apparatus as described in claim 1 wherein the said second drum is provided with a plurality of circumferential grooves adapted to receive a corresponding number of threads.

3. An apparatus for a liquid treatment of a warp of closely spaced rapidly moving threads comprising an open trough for a treating liquid, a freely rotatable drum mounted within said trough and disposed in part below the normal liquid level, a vessel for collecting and returning said liquid to said trough, a flat elongated sup porting plate disposed at an acute angle with respect to the liquid level and having an .end extending below the liquid level and adjacent to the submerged portion of said drum with the opposite end thereof extending over said vessel, a second freely rotatable drum mounted over said vessel, at least two small deflecting plates arranged substantially at right angles to said supporting plate and positioned between said second drum and the end of said supporting plate, said deflecting plates defining slots for liquid to travel therethrough into said vessel and a positively driven roller for propelling a warp of threads be- 15 2,7 69,727

tween the two said drums and in close proximity to said plate.

4. An apparatus as described in claim 3 wherein the said second drum is provided with a plurality of circumferential grooves adapted to receive a corresponding number of threads.

5. An apparatus as described in claim 4 wherein said vessel is mounted outside of said trough.

6. An apparatus as described in claim 4 wherein said 10 vessel is mounted within said trough.

References Cited in the file of this patent UNITED STATES PATENTS Walmsley Oct. 14, 1952 Bowen et a1. 'Nov. 6, 1956

Images