US2731667A

US2731667A - Wet spinning apparatus

Info

Publication number: US2731667A
Application number: US226593A
Authority: US
Inventors: William H Bradshaw
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1951-05-16
Filing date: 1951-05-16
Publication date: 1956-01-24
Anticipated expiration: 1973-01-24

Description

Jam. 24, 1956 w. H. BRADSHAW 2,731,667

WET SPINNING APPARATUS Filed May 16, 1951 2 Sheec-Sheet 1 INVENTOR. i WILLIAM H. BRADSHAW ATTORNEYS.

Jan. 24, 1956 Filed May 16. 1951 W. H. BRADSHAW WET SPINNING APPARATUS '2 Sheets-Shet 2 INVENTOR. WILLIAM H. BRADSHAW ATTORNEYS.

United States Patent WET SPINNING APPARATUS William H. Bradshaw, New Rochelle, N. Y., assignor to Celanese Corporation of America, New York, N. Y., a corporation of Delaware Application May 16, 1951, Serial No. 226,593

Claims. (Cl. 18-8) This invention relates to the production of viscose rayon filamentary materials and relates more particularly to a novel process and apparatus for the production of viscose rayon filamentary materials in a continuous manner.

An important object of this invention is to provide a novel process and apparatus for the production of viscose rayon filamentary materials in a continuous manner which will be especially efiicient in operation and simple in construction.

Other objects of this invention, together with certain details or" construction and combinations of parts, will be apparent from the following detailed description and claims.

In the production of viscose rayon filamentary materials, particularly viscose rayon fibers of staple length, it is necessary to subject said filamentary materials to a series of successive treatments under closely controlled conditions to obtain products having desirable physical properties. Advantageously, to minimize the expense involved in producing the viscose rayon filamentary materials, the successive treatments should be carried out automatically and with a minimum of manual labor.

According to the present invention, there is provided a novel process and apparatus for the production of viscose rayon filamentary materials which will fulfill the foregoing requirements, the apparatus being divided into four sections: a spinning section, a stretching section, a cooling section, and a cutting and opening section, through which sections the viscose rayon filamentary materials pass in succession. The present application relates specifically to the spinning section of the apparatus. In the spinning section, a viscose composition is pumped through a spinning jet, in the form of a strand containing up to 5000, or more, filaments into a coagulating medium which initiates the setting of the filaments. The strand and the coagulating medium are then caused to flow inthe same direction through a generally U-shaped spinning tube wherein the setting of the filaments continues. As the strand emerges from the spinning tube, it is combined with the strands from one or more jets into a tow and is passed around a godet wheel which determines the speed of the tow and also provides a resistance against which the tow can be stretched by a drum over which it passes later on.

"The term filamentary materials is employed herein to' include filaments of indefinite length as well as fibers of staple length.

A preferred embodiment of the apparatus of this invention is shown in the accompanying drawings wherein:

Fig. 1 is a cross-sectional view of the apparatus, taken on an enlarged scale along the line 11 in Fig. 2, inthe direction of the arrows,

Big. 2 is a front elevational view, with portions broken away, of the apparatus,

Fig. 3 is a cross-sectional view, taken along the line 3-3 in Fig. 1, in the direction of the arrows, and

Fig. 4 is a detail perspective view, on an enlarged scale 2,731 ,fibi Patented Jan. 24, 1956 and with parts broken away, of the inlet tunnel for guiding the tow into the spinning tube.

Spinning section Referring now to the drawings, and more particularly to Figs. 1 and 2 thereof, the reference numeral 21 designates conduits through which a suitably ripened viscose composition is pumped by any suitable means (not shown) through a goose-neck, indicated generally by reference numeral 22, to a spinning jet, indicated generally by reference numeral 23. The spinning jet 23 is positioned in a trough 24 into which a stream of a suitable coagulating medium is pumped continuously through a conduit 25. The viscose composition emerges from the spinning jet 23 into the coagulating medium in the form of a strand 26 containing up to about'5000, or more, individual filaments which are caused to set by the action thereon of the coagulating medium. The strand 26 together with the coagulating medium then pass through suitable guide means, such as an inlet funnel 27, into a generally U- shaped spinning tube 28, composed of a vertically disposed conduit 29, a horizontally disposed connecting conduit 31 and avertically disposed conduit 32, all joined together with elbows 33. Grooved guides 34 are provided in each of the elbows 33 to direct the strand 26 through the tube 28 and are positioned so as to guide the strand 26 along the center lines of the

conduits

29, 31 and 32 thereby minimizing the development of turbulence in said conduits; The shape and positioning of the grooved guides 34 also tend to cause the fiow of the coagulating medium to hold the strand 26 away from the guide thus reducing greatly the tension developed by the friction of the strand 26 against the said guide.

A constant .head of coagulating medium is maintained on the inlet funnel 27 by pumping an excess of said medium into the trough 24 and permitting said excess to overflow into a channel 35 connected to a trough 36 which extends parallel to and is positioned adjacent the trough 24. The strand 26 and the coagulating medium emerge from-the spinning tube 28 into the trough 36 through suitable guide means, such as an outlet funnel 37, whose cross-sectional area increases toward the discharge end thereof whereby the velocity of the coagulating medium will decrease immediately prior to its discharge from said outlet funnel. As a result, the coagulating medium will show little or no tendency to spurt from said outlet funnel as a column enclosing the tow 26, although a certain amount of the coagulating medium will, of course, be held within the interstices between'the filaments of said strand. The coagulating medium which overflows .into the channel 35 and which flows through the outlet funnel 37 is drained from the trough 36 through a discharge conduit 38 which is made sufficiently large to prevent the accumulation of large quantities of liquid in said trough. A screen 39 spaced slightly above the fioor of the trough 36 traps any broken fibers that may be formed during the spinning operation and keeps them from flowing into the discharge conduit 38. The screen 39also holds back thestrand 26 which emerges from the outlet funnel 37 when starting up the apparatus, permitting the operator to string up the said strand without having to remove any of the strand from the trough 36 during the start up period. The trough 36 is provided with a removable cover 41 and is connected to an exhaust conduit 42 through which any gases or fumes that are. liberated during the spinning operation may be drawn oli.

As is shown more clearly in Fig. 4, the inlet funnel 27 is provided with radially extending wings 43 and is seated slidably in a collar 44 extending upwardly through the floor ofthe trough 24. One of the wings 43 is provided with a groove 45 in thejface thereof which groove is adapted to receive a pin 46 projecting from the collar 44.

When .the pin 46 is contained within the groove 45, the inlet funnel 27 is held in elevated position at a point spaced only slightly below the spinning jet 23. In this position, the flow of the coagulating medium into the inlet funnel 27 and through the spinning tube.28will carry the strand 26 into and through said .tube. .Once-ihestrand 26 has been threaded through the tube 28, the inlet funnel 27 may be returned to'its normal spinning position, as shownin Fig. 2 of the drawings,-in WhiChii isspaced further away from the spinning jet 23 than-at the start-ofthe spinning operation. This mode of starting the spinning operation eliminatesthe necessity for :wiping the face of the spinning jet '23 during the starting period and thereby reduces the amount of laborinvolved in said start up.

After emerging from the outlet funnel 37, the strand 26 passes over a two-finger guide46', which "wipes away a portion ofthecoagulating medium adhering-thereto, and then through 'a slot 47 in the'cover 41 to a-godet wheel, indicatedgenerally by reference numeral 48. The strands 26 from three spinning jets 23 are joined on *the 'godet wheel 48 to form a=tow-49 which is led from the godet wheel 48 over a guide pin 51 which is positioned "at a level higher than said godet Wheel. Any desired number of spinning jets 23 and godet wheeis 48 may be included in'thespinning section of the apparatus, and a'tow'49leaving any oneof 'thegodet wheels will "ride over the pins 51 without coming into "contact with any'other of the go'det wheels.

The tensions to which the filaments in the strands 26 are subjected in their passage from the spinning jet '23 to the godet wheel '48may'be closelycon'trolled, to produce products'having the most desirable physical properties, by regulating the velocity of the 'viscose composition through the said spinning jets, the spacing between the spinning jet 23 and the inlet funnel 27, 'thevelocity'with which the coagulating medium flows :through the spinning tube 28 which can be altered by changing the effective liquid head under which said medium flows through said spinning tube and/or the diameter 'of said spinning tube, andthe speed of the godetwheel 48. The two-finger guide 46' may also be adjusted to produce a desirable small additional tension between the said guide and the godet wheel 48. Under normal operating conditions, the 'filaments travel faster than the coagulating medium immediately after emerging from the spinning jet 23, then thecoagulating medium travels faster than the filaments as -it flows into and through the-first portion of the spinning tube 28, and finally the coagulating medium travels at the same rate as or somewhat slower than the filaments as it flows through the 'last portion of the spinning tube.

In addition topermitting close control of all the condi-' tions under which the strand 26 is produced, the spinning section of -the apparatus of this invention provides a long bath travel in a very small space horizontally which brings the spinnerette 23 and the godetwheel 48 into such close proximity that stringing up by a single operator is'extremely simple. 'The spinning sectionis also self-threading from the spinnerette 23 through the spinning tube 28 and is free from moving guides or rollers so that its construction and maintenance is simplified. The spinning jets 23 are effectively separated one from the other so that fresh coagulating medium is brought 'to the filaments emerging from each of said jets without having been contaminated or-its concentration changed by contact with viscose .from any other jet. Moreover, the filaments from one jet cannot interfere in any way with those of other jets either during start up or when there is a breakdown.

In producing a strand containing a large number of individual filaments, it'is important to provide anadequate flow of coagulating medium to each .of the filaments as it emerges from the spinning jet .23 to insure that .each of the filaments is treated in the same :manner and that the gases liberated from the viscose composition are swept away from the vicinity of the spinning jet. If an adequate flow of coagulating medium is not provided, a sutlicient 7 quantity of the gases liberated from the viscose composi;

tion may accumulate on the lower face of the spinnerette to form bubbles which may interrupt the continuity of spinning of one or more filaments, particularly, where as here, the filaments are spun downwardly from the lower face of the spinnerette. Inapplication Serial No. 224,353, filed May 3, 1951, of Russell 0. Denyes, now U. S. Patent No. 2,673,368,-dated.Mar ch 13, .1954, there are disclosed spinnerettes that are specially adapted to be used in the. apparatus of the present invention and 'will insure ;an adequate flow of coagulating medium to the filaments emerging from each of the apertures in the spinnerette.

Since the solutions employed and produced :during the manufacture of the viscose fibers .are corrosive, the several parts of the apparatus employed for handling the same are made of or coated with corrosion resistant material such as hard rubber, plastics, ceramics, lead, stainless steel and the like depending upon the use to which each part is put and the mechanical strength requiredthereof.

It is to be understood that the foregoing detailed :de-' scription is given merely by way .of illustration and that many variations may be made therein without departing from "the spirit of my invention.

Having described my invention, what I desireto'secure by Letters Patent is:

1. An apparatus for the production of filamentarymaterials comprising a trough for holding a coagulating medium, a second trough contiguous to .said first trough, a.

channel communicating with said troughs for conducting overflow coagulating medium from said first trough to said second trough, a spinning jet'positioned in said first trough for extruding a filament-forming composition into said coagulatingmedium in the form of filamentary materials,

and a generally U-shaped spinning tube extending from said first trough to said second trough for carrying the filamentary materials and coagulating medium from said first trough to said second trough.

2. An apparatus for the production of filamentarymaterials, comprising a longitudinally extending trough .tor holding a coagulating medium, asecond trough contiguous and parallel to said first trough, a channel between and communicating with said troughs for conducting overflow coagulating medium .from said first trough to said second trough, a plurality of spinning jets in :said first trough for extruding a filament-forming composition into said coagulating medium in the form of filamentary materials, .and a plurality of generally U-shapedspinningatubes extending from said first trough to said second itrough :for carrying filamentary materialsand coagulating medium from said first trough to said second trough.

3. .An apparatus for the production of filamentary materials, comprising a trough for holding a coagulating medium, aspinning jet positioned in said trough for extruding a filament-forming composition into said coagulating medium in the form of filamentary materials, a spire ning tube extending away from said trough for carrying the filamentary materials and the coagulating medium away from said trough, a movable inlet funnel cooperating with said spinning tube, and means for holding said inlet funnel in raised position so as to reduce .the dis? tance between the spinning jet and the inlet funnel at the start of the spinning operation to assist in guiding the filamentary materials through the spinning tube and in reducing the wiping of the spinning jet required at the start of the spinning operation.

4. An apparatus'for the production of filamentary materials, comprising atrough for holding a coagulating medium, a'spinning jet positioned in 'said trough for extruding a filament-forming composition into said coagulating medium in the form of filamentary materials, a 'second'trough, a generally U-shaped spinning tube extending from said first trough to said second trough for carrying the fila' mentary materials and the coagulating medium from" the first trough to thesecond trough, a movable inlet funnelcooperating with said spinning tube, and means for holding said inlet tunnel in raised position so as to reduce the distance between the spinning jet and the inlet funnel at the start of the spinning operation to assist in guiding the filamentary materials through the spinning tube and in reducing the wiping of the spinning jet required at the start of the spinning operation.

5. An apparatus for the production of filamentary materials, comprising a trough for holding a coagulating medium, a spinning jet facing downwardly positioned in said trough for extruding a filament-forming composition vertically downward into said coagulating medium in the form of filamentary materials, a second trough positioned adjacent to said first trough, a generally U-shaped spinning tube having its legs positioned vertically upward and having one leg positioned beneath said spinning jet, said tube extending from said first trough to said second trough for carrying the filamentary materials and the coagulating medium from said first trough to said second trough, an inlet funnel for guiding the filamentary materials and the coagulating medium into the leg of the spinning tube positioned beneath said spinning jet, said inlet tunnel being moveable to reduce the distance between the spinning jet and the entrance to said inlet funnel at the start of the spinning operation to assist in guiding the filamentary materials through the spinning tube and in reducing the Wiping of the spinning jet required at the start of the spinning operation, guides positioned in the spinning tube for guiding the filamentary materials along the center line of the spinning tube to minimize .the development of turbulence in the spinning tube, a discharge funnel for guiding the fibers and the coagulating medium out of the spinning tube, said discharge funnel increasing in cross-sectional area toward the outlet end thereof whereby the velocity of the coagulating medium flowing therethrough will decrease toward the outlet end thereof and the coagulating medium will not spurt from the outlet end of said funnel, and an overflow from said first trough to said second trough for maintaining a constant head of coagulating medium in said first trough on the inlet funnel.

References Cited in the file of this patent UNITED STATES PATENTS 1,022,097 Linkmeyer Apr. 2, 1912 2,027,419 Dreyfus Jan. 14, 1936 2,210,826 Williams Aug. 6, 1940 2,243,116 Ostermann May 27, 1941 2,288,982 Waterman et al July 7, 1942 2,313,006 Ufnowski Mar. 2, 1943 2,447,994 Wicker Aug. 24, 1948 2,450,750 De Locotte et a1 Oct. 5, 1948 2,502,972 McCallum Apr. 4, 1950 2,517,711 Pool et al. Aug. 8, 1950 2,532,458 New Dec. 5, 1950 2,558,734 Cresswell July 3, 1951 2,559,700 Bauer July 10, 1951

Claims

1. AN APPARATUS FOR THE PRODUCTION OF FILAMENTARY MATERIALS COMPRISING A TROUGH FOR HOLDING A COAGULATING MEDIUM, A SECOND TROUGH CONTIGUOUS TO SAID FIRST TROUGH, A CHANNEL COMMUNICATING WITH SAID TROUGHS FOR CONDUCTING OVERFLOW COAGULATING MEDIUM FROM SAID FIRST TROUGH TO SAID SECOND TROUGH, A SPINNING JET POSITIONED IN SAID FIRST TROUGH FOR EXTRUDING A FILAMENT-FORMING COMPOSITION INTO SAID COAGULATING MEDIUM IN THE FORM OF FILAMENTARY MATERIALS, AND A GENERALLY U-SHAPTED SPINNING TUBE EXTENDING FROM SAID FIRST TROUGH TO SAID SECOND TROUGH FOR CARRYING THE