US2983952A - Wet spinning apparatus - Google Patents

Description

May 16, 1961 w. R. EDWARDS EIAL 5 WET SPINNING APPARATUS Filed Dec. 22. 1954 2 Sheets-Sheet 1 ,8 E c 0 m/ x3 MM M w 4/4 m 1 1 m y m 4 u W E x M N Y Y m m y 1961 w. R. EDWARDS EI'A'L 2,983,952

WET SPINNING APPARATUS 2 Sheets-Sheet 2 Filed Dec. 22, 1954 INVENTORS W44 r6 A? [01/4905 WET SPINNING APPARATUS Walter R. Edwards, Cumberland, Md., and Norman S.

Pliner, Charlotte, N.C., assignors to Celanese C'orporation of America, New York, N.Y., a corporation of Delaware Filed Dec. 22, 1954, 'Ser. No. 477,062

Claims. (Cl. 18-8) This invention relates to the spinning of artificial filimentary materials and relates more particularly to the wet spinning of continuous artificial filaments.

It is an object of this invention to provide an improved apparatus for the wet spinning of artificial filamentary materials.

Another object of this invention is the provision of a novel and eflicient apparatus for wet spinning continu' ous artificial filaments while stretching said filaments.

Still another object of this invention is to provide an apparatus for Wet spinning artificial filaments which apparatus makes it possible to start the spinning operation easily and with a minimum of dismantling of the apparatus, and which apparatus may be easily erected or taken apart for cleaning or for replacement of the elements thereof.

Other objects of this invention will be apparent from the following detailed description and claims. a

One form of the apparatus of this invention is illustrated in the accompanying drawings wherein Fig. 1 is a vertical cross-sectional view of the wetspinning apparatus,

Fig. 2 is a plan view taken along the line 2-2 of Fig. 1,

Fig. 3 is a view taken along the line 3-3 of Fig. 1,

Fig. 4 is a view taken along the line 4-4 of Fig. 1, with parts broken away,

' Fig. 5 is a view taken along the line 5-5 of Fig. 1,

Fig. 6 is a detail enlarged view in section showing the manner in which a spin pot is sealed to its cover,

Fig. 7 is a view taken along the line 7-7 of Fig. 1.

Like reference numerals indicate like parts throughout the several views of the drawings.

Referring now to the drawings and particularly Fig. 1, reference numeral 11 designates generally a spin pot, circular in horizontal cross-section, composed of a main body 12, carried by a support 13, and a removable cover 14 adapted to be tightly sealed to said main body 12. Within the spin pot 11 there is mounted a spinnerette 16 having numerous fine apertures through which a spinning solution is extruded at a uniform rate in the form of filaments 17, the spinning solution being supplied through a pipe 18 to a spinnerette assembly 19 at the top of which the spinnerette 16 is mounted. The spinnerette 16 and the assembly 19 are disposed along the vertical axis of the spin pot 11. As the spinning solution emerges in filament form from the orifices of the spinnerette 16 it nited States Patent 0 is subjected to the action of a liquidcoagulating or set- 2,983,952 Patented May 16, 1961 spaced above the bottom of the spin pot 11 and annularly disposed within the spin pot between upper and lower screens 26 and 27, respectively, the coagulating liquid emerges above the top of the tubular member 22, at about the level of the spinnerette 16. The mass of diffuser material 24, which is preferably composed of corrosion-resistant metallic wool, such as stainless steel wool, copper wool or aluminum wool, acts to cause the coagulating medium to follow a circuitous path through said diffuser material and thus reduces the velocity of the coagulating medium and substantially eliminates the turbulence therein so that the coagulating medium leaves the diffuser material in a uniform non-turbulent annular stream all around the spinnerette 16. Some of the coagulating medium flows past the gasket 23 and provides a desirable gentle flushing action in the space around the pipe 18 and assembly 19.

As previously stated the spin pot cover 14 is adapted to be tightly sealed to the main body 12 of the spin pot. To this end the lower portion of this cover 14 is provided with an annular resilient gasket 28 retained in an internal annular groove 29 (see Fig. 6) and adapted to be pressed against an internal shoulder 31 of said cover 14. Below the groove 29 the cover 14 has a portion of increased internal diameter 32 while at the bottom of the cover there are a plurality of spaced inwardly directed lugs 33 (see also Fig. 7). The main body 12 is provided with a corresponding number of spaced outwardly directed lugs 34 of such size that the cover lugs 33 may pass through the spaces between the main body lugs 34, and vice versa. The upper surfaces of the cover lugs 33 are adapted to engage the lower surfaces of the main body lugs 34, one or both of these surfaces being at such an angle to the horizontal that when the cover 14 is rotated about its vertical axis in one direction so as to cause the upper surfaces of the cover lugs 33 to slide along the lower surfaces of the lugs 34, the cover lugs 33, and therefore the cover 14 itself, are forced downwardly, thus forcing the gasket 28 against the top edge 36 of the main body 12 and pressing said gasket between said top edge and the shoulder 31, thereby sealing the cover 14 tightly to the main body 16. Conversely, when the cover 14 is rotated in the opopsite direction, the cover lugs 33 are brought to a position where they are free of. the main body lugs 34 and may be passed between said main body lugs on raising and removal of the cover. Handles 37 are bolted to the cover 14 to aid in the rotation and raising thereof.

The spin pot cover 14 is provided with a central aperture 41 through which the upwardly moving coagulating liquid and filaments 17 may pass to the interior of an elongated spin tube, indicated generally as 42. The lower section 43 of this spin tube 42 is bolted and sealed to the top of the cover 14. This lower section 43 has a bottom zone 44, whose internal diameter is equal to the internal diameter of the aperture 41 in the cover, above which is a tapered zone 46 of decreasing internal diameter and a further zone 47 of constant smaller internal diameter. Most of the lower section 43 is surrounded by thermal insulation '48 which aids in maintaining the temperature of the coagulating liquid at the desired constant level. The insulation 48 is enclosed within a cylindrical housing 49 and is covered by an annular plug 51. If desired, vent holes may be provided in the housing 49 to permit the escape of any moisture which may tend to accumulate in the insulation 48.

The spin tube 42 comprises, in addition to the lower section 43 described above, an upper section 56, spaced from said lower section, of the same internal diameter as the top of the lower section. A flexible bellows 57 preferably made of rubber, natural or synthetic, connects the two sections together. The upper section 56 is rigidly 3 connected to an overflow chamber 58. The end portions of the bellows 57 fit resiliently and tightly around the adjoining ends of the upper and lower sections 56 and 43 and also around the plug 5-1 and housing 49 so that none of the coagulating liquid escapes from the ends of the bellows. The flexibility of the bellows 57 permits the lower section 43 and the attached spin pot cover 14 to be displaced angularly about a horizontal axis, to be moved vertically and to be swung in pendulum fashion so as to permit the interior of the spin pot 11 to be exposed. This makes it easy for an operator to remove the spin pot cover 14 from the main body 12 of the spin pot when it is necessary for the operator to wipe the spinnerette 16 and start the spinning operation. Of course there should be no substantial amount of liquid in the spin tube 42 when the spin pot cover 14 is removed. In order to permit free non-turbulent flow of the coagulating medium up the spin tube 42, the inner diameters of the folds of the bellows should be equal to or greater than the inside diameters of the spin tube sections 56 and 43. Preferably, the lower end of the bellows is provided with a skirt 59 to shield the insulation 48 from any coagulating medium which may drip down from portions of the apparatus above said bellows.

In the preferred form of the invention, the spin tube sections 43 and 56, the rubber bellows 57, the cover 14, the main body 12 of the spin pot 11, the tubular member 22, the spinnerette 16 and the spinning head 19 are all substantially circular in horizontal cross-section and are all concentric.

After passing through the upper section 56 of the spin tube 42 the coagulating liquid spills over the top 61 of said section, then passes through a screen 62 in the overflow chamber 58 and is removed, for reuse, through an outlet pipe 63. The filaments, which converge as they pass through the spin tube 42, emerge from the stream of coagulating liquid at the top of the section 56 and are drawn, in the form of a bundle or yarn, by the action of a draw roll 64 over a plurality of fixed pins 66, 67, 68, then around freely rotatable pulleys 69 and 71 and through a eyelet 72. During passage of the yarn around the pins 66, 67, 68 and pulleys 69, 71 the coagulating liquid adhering to the yarn is removed by wiping on the pins and also is thrown oflz' by the centrifugal force during the change of the direction of the yarn on the pulleys.

The pins 66, 67, 68 and pulleys 69, 71 are mounted on a bent frame 73 which is in turn supported by a bracket 74 fixed to the overflow chamber 58, with the trapezoidal vertical lower portion 76 of the frame 73 fitting removably into a correspondingly trapezoidally shaped slot in said bracket. The frame 73 is made up of two vertical platelike portions 77, 78 disposed in intersecting planes, one portion 77 being at right angles to the aforesaid trapezoidal lower portion 76, and carrying the horizontal axle of the lower pulley 71, which pulley is parallel to said portion 77. The other portion 78 of the frame makes an obtuse angle, e.g. 150, with said first portion 77 and carries the pins 66, 67, 68 and the horizontal axle of the upper pulley 69, all at right angles to said other portion 78, the pulley 69 being parallel to said portion 78. The pins 66, 67, 68 are all horizontally disposed and so arranged that the yarn changes in direction to a small extent as it passes over each pin and is guided away from the vertical axis of the apparatus to the outer edge of the top pulley 69. The pins are desirably made of a suitable metal or other material which is resistant attack by the coagulating medium and to the erosive effect of the yarn passing over its surface at high velocities. Preferably, the lower pulley 71, eyelet 72 and draw roll 64 are so mounted that the yarn passes in an unbroken straight line tangent to both said pulley 71 and draw roll 64 without making contact with the surfaces of said eyelet.

The pulleys 69 and 71 have concave outer running surfaces 79 and 81, respectively, and their edges are provided with tapered slots 82 and 83, respectively, extending radially below said working faces. These slots 82 and 83 enable a knife or similar tool to be inserted below the running surfaces of the pulleys so that any broken filaments of yarn which adhere to said running surfaces may be cut away and removed without damage to said running surfaces. In one preferred form the slots 82 and 83 are tapered inwardly at an included angle of about down to the lowest level of the running surfaces 79, 81.

The bent frame 73, pins 66, 67, 68 and pulleys 69, 71 are enclosed within a removable housing 84 which rests atop the overflow chamber 58 and serves to prevent loss of coagulating liquid and vapors. The housing 84 is retained in position by an annular lip 86 of the overflow chamber 58. Any coagulating liquid dripping from the outside of the eyelet 72 is caught in a cup 87 and returned to the interior of the overflow chamber 53 through a hole 88.

The apparatus of this invention is particularly suitable for use in processes in which the filaments being extruded into the coagulating liquid are stretched in said liquid while they are still in a swollen plastic state. For example it may be employed with very good results in a process such as that described in the copending application of Rulison et al., S.N. 325,798, filed December 13, 1952, now Patent No. 2,777,160.

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Apparatus for the wet-spinning of filamentary materials comprising a vessel, means for supplying a coagulating liquid to said vessel, an apertured spinnerette within said vessel, means for supplying a spinning solution to said spinnerete through which the spinning solution is forced into the coagulating medium to form filaments, a cover for said vessel, said cover having an opening for the passage of said filaments and coagulating liquid, a plurality of aligned tubes for the successive passage therethrough of said filaments and coagulating liquid emerging from the opening in said cover, one of said tubes being fixed to said cover, and a flexible bellows connecting the end of said fixed tube with the adjacent end of the next tube, said cover being constructed and arranged to be sealed to said vessel by rotation of said cover about the axis of the tube which is fixed to said cover, said rotation being permitted by the flexible bellows connection be tween said tubes.

2. Apparatus for the wet-spinning of filaments, comrising a vessel, a spinnerette in said vessel, means for supplying a spinning solution to said spinnerette, means for supplying a coagulating liquid to said vessel and means, comprising a pad of metallic wool in said vessel, for directing said liquid in a non-turbulent annular stream around said spinnerette.

3. Apparatus as set forth in claim 2 in which said pad of metallic wool is annularly disposed concentrically of said spinnerette and is supported on a screen.

4. Apparatus for the wet-spinning of filaments, comprising a vessel circular in horizontal cross-section, an upwardly directed spinnerette in said vessel and situated at about the vertical axis of said vessel and spaced from the bottom of said vessel, means for supplying a stream of a coagulating liquid to the bottom portion of said vessel, a tubular member laterally spaced from and extending approximately to the level of the spinnerette for confining the stream of coagulating liquid to an annular path around said tubular member and spaced from the vertical axis of said vessel, an annular pad of metallic wool disposed around said tubular member in the path of said confined annular stream, and means for support- 5 6 ing said spinnerette and for supplying spinning solution 2,193,316 Feikes Mar. 12, 1940 thereto disposed within said tubular member. 2,642,333 Tomonari et -al. June 16, 1953 5. Apparatus as set forth in claim 4 in which said tubu- 2,700,794 Taylor et a1. Feb. 1, 1955 lar member is p y fl 2,732,586 Bradshaw et a1. Jan. 31, 1956 5 2,745,136 Deboutteville May 15, 1956 References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS 1,977,611 Bani-ga oct. 23, 1934 733,178 Germany 18, 1943

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