US 3182106 A
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May 4, 1965 YOSHIMASA FUJ|T A ET AL SPINNING MULTI-COMPONEN'I FIBERS 2 Sheets-Sheet 1 Filed July 10, 1962 l l C)? A 7' TORNE' Y May 4, 1965 YOSHIMASA FUJlTA ET AL SPINNING MULTI-COMPONENT FIBERS 2 Sheets-Sheet 2 Filed July 10, 1962 4 rlllllv llvlllsaw m 7 Willi/ m IIIIIIIII E WIIQVIAJWW 1a. 11/! Ill/Ill FIE-ll zg-F V R. a to are Shm 0 BY "chi Z ATTORNEY United States Patent 3,182,106 SPINNING MUL'II-CGMPQNENT FIBERS Yoshimasa Fajita, Keitaro Shimoda, and Keiichi Zoda,
Saidaiji, Japan, assignors to American Cyanamid Company, Stamford, Conn, a corporation of Maine Filed July 10, 1962, Ser. No. 208,884 Claims priority, application Japan, July 14, 1961, 36/25,.393 Claims. (Cl. 264-171) This invention relates to producing textile fibers possessing permanent crimp, and more particularly, to method and apparatus for spinning multi-component filaments from at least two different fiber-forming spinning solutions by extruding them concurrently through a common orifice.
It is known to provide fibers having permanent crimps by making such fibers of at least two different materials intimately associated as a single fiber. Because of the diiferential shrinkage of the different materials of which such fibers are produced, a permanent crimp is provided therein. It has been, however, a problem not satisfactorily solved prior to the present invention, to provide such filaments which are uniform, both along the length of any one fiber and from fiber to fiber within the same group of fibers.
For example, it has been proposed to produce a bicomponent fiber comprising a core of a first component and a sheath of a second component surrounding the core in either a concentric or eccentric relationship. Another proposal was to utilize two kinds of spinning solutions extruded together through the same orifice of a spinnerette so as to make them coexist without interrningling in the spun filament. However, in each of the aforementioned known methods, a satisfactorily uniform filament is not produced when utilizing a plurality of orifices in a multiple orifice spinnerette. This results from the inability of the prior art techniques to suitably control the flow of each of the solutions through each of the orifices of a multiple orifice spinnerette so as to assure that each filament produced from such spinnerette has the proper proportions of each component constituting it. Thus, such prior art filaments as would be produced would show, in the group from any single spinnerette, some filaments having more and other filaments having less than the desired fraction of one of the components causing undesirable variations in the physical properties of the filaments produced.
It is an object of this invention to produce filaments or fibers possessing permanent crimp having a higher degree of uniformity than can be produced within the teachings of the prior art.
It is a further object of this invention to produce fibers wherein two or more fiber-forming components conjugate together firmly, without intermingling, in the manner of a bi-metallic strip, in a definite and uniform proportion as they pass through the spinnerette orifices.
It is yet another object of this invention to provide a multi-component fiber having superior and more uniform adhesion of the components to each other by providing a uniform and definite slight intermingling of the components at the interfaces between them.
These objects and other objects and advantages as will appear hereinafter are mainly achieved by the novel method and apparatus of this invention wherein a spinning solution for each component is caused to flow as a thin confined film moving in laminar fiow in interfacial contact with another such spinning solution prior to extrusion of said spinning solutions concurrently through the orifices of the spinnerette into a suitable coagulating medium. The orifices are preferably arranged in the face of the spinnerette in rows such that the center-to-center spacing of the orifices in any single row is substantially equal to the maximum diameter of the orifices (which maximum diameter occurs adjacent the face of the spinnerette which is within the spinnerette holder).
For a clearer and more detailed understanding of this invention, reference may be had to the subjoined description read in conjunction with the accompanying drawing wherein:
FIGURE 1 is a longitudinal cross-section of a preferred embodiment of a device of this invention;
FIGURES 2, 3 and 4 are cross-sections of the same apparatus taken along lines II-II, IIIIII, and IV-IV of FIGURE 1;
FIGURE 5 is a partial view, on an enlarged scale, of the spinnerette taken on the line VV of FIGURES 1 and 6.
FIGURE 6 is a cross-sectional view'taken on the line VI'VI of FIGURE 5;
FIGURE 7 is a longitudinal cross-section of another embodiment of this invention;
FIGURE 8 is a cross-section as taken along the line VIII-V III of FIGURE 7;
FIGURE 9 is a partial view, on an enlarged scale, taken along the line IXIX of FIGURES 7 and 10;
FIGURE 10 is a cross-sectional view taken on the line XX of FIGURE 9;
FIGURE 11 is an enlarged cross-sectional view, sche matically represented, of the fiber obtained by the spinning device of FIGURES 1 through 6;
FIGURE 12 is an enlarged cross-sectional view, schematically represented, of the fiber obtained by the spinning device of FIGURES 7 through 10.
Referring next to the drawing and, more particularly, to FIGURES I through 6, there is illustrated a spinning device for producing bi-component fibers generally com prising a spinnerette 11, a guide plate 13, and a cylindrical sleeve 15 suitably supported in a spinnerette holder comprising a cap 17 and nut 18 on the end of supply tube 19.
Spinnerette 11 is provided with a plurality of orifices 21 arranged in rows which are spaced from each other. The orifices 21 in any single row are placed near each other at a spacing which is substantially equal to the inside diameter of such orifices at the back portion of spinnerette 11 as is illustrated in FIGURE 5.
As a result of such spacing, it is seen that orifices 21 in any single row are substantially tangent to each other at their maximum diameter which maximum diameter occurs (see FIGURE 6) adjacent the face of the spinnerette 11 which is inside the spinnerette holder. While spinnerette 11 has been illustrated as having orifices 2-1 disposed in a plurality of straight rows, it is to be understood that the orifices may be disposed in a single straight row, a single circular row, a plurality of concentric circular rows, etc.
Adjacent the back face of spinnerette 11 is guide plate 13 which is provided with a plurality of Y-shaped channels 23. The width of the base of each Y-shaped channel in guide plate 13 is substantially equal to the maximum diameter of orifices 21 at the back portion of spinnerette 11 substantially as illustrated in FIGURE 6. The length of each Y-sha'ped channel 23 is substantially equal to the length of the row of orifices 21 with which it cooperates. The Y-shaped channels in guide plate 13 are spaced apart .a distance equal to the spacing between the rows of orifices in spinnerette 11 and are substantially co-extensive in length with such rows of orifices.- While guide plate 13 has been shown as an integral unit, suoh plate may be composed of a plurality of pieces suitably secured together for mounting within the spinnerette holder adjacent the back face of spinnerette 11.
Cylindrical sleeve 15 may be considered as having its interior divided into two sections; an inlet section into which two diiferent spinning solutions are introduced and an outlet section which delivers these two spinning solutions to guide plate 13 for transmission to orifices 21 of spinnerette 11. The inlet section of cylindrical sleeve is provided with a baffle 25 which serves to divide the inlet section into two chambers 26 and .27. The outlet section of cylindrical sleeve 15 is provided with a plurality of slots 29, which may be considered as belonging to two groups, a first group 29 and a second group 30. Each of the slots 29 in the first group is provided with an opening 32 communicating with a first chamber 26 in the inlet section and is isolated from chamber 27, whereas each of the slots 30 in the second group is provided with an opening 33 communicating with chamber 27 .and is isolated from chamber 26.
The plates of cylindrical sleeve 15 that serve to separate slots 29 and 30 from each other each terminate with V-shaped edges which, when cylindrical sleeve 15 is properly positioned adjacent guide plate 13 as illustrated in FIGURE 1, coact with the upper portions of Y-shaped channels 23 in guide plate 13 to provide narrow V-shaped channels 35.
When properly assembled, as illustrated in the drawings and as previously described, a different spinning solution is introduced into each of the chambers 26 and 27 on the inlet side of cylindrical sleeve 15 from separate supply sources, not shown. The first spinning solution (Solution A) flows from chamber 26 through openings 32 to alternate channels 29 and down one arm of each V- shaped channel leading toward orifices 21. The second spinning solution (Solution B) flows from chamber 27 through openings 33 to the other set of alternate channels 3% and thence down the other arms of V-shaped channels 35 toward orifices 21. It will be noted that both arms of V-shaped channels 35 meet at an acute angle and discharge at the apex thereof into a common narrow channel 36 which is the base of the Y-shaped channel 23.
Since the legs of V-shaped channels 35 are very thin and since channels 36 are likewise quite thin, and since the spinning solutions commonly used are quite viscous and flow at relatively low rates, the film-like flows from the two legs of each V-shaped channel 35 comprising Solution A and Solution B, respectively, flow in laminar flow without mixing down channels 36 to the row of orifices 21. -It is to be noted that the interface between Solution A and Solution B extends the full length of channel 23 and flows uniformly over an extended distance, i.e., from the apex of V-shaped channel 35 to orifices 21 (see FIGURE 6). Thus, it is seen that Solution A and Solution B together completely fill the entire length and width of channel 36 while flowing as a pair of films comprising a single film moving as a unit in laminar flow over an extended distance in the direction of flow. By proper adjustment of the rates of flow of Solution A and Solution B fed into channels 26 and 27, the interface between the film of Solution A and the film of Solution B flowing down channels 36 can be centered over the row of orifices and extruded there-through as bicomponent streams of viscous liquid.
Upon subsequent coagulation of this liquid into fiber form, fibers having the appearance shown in FIGURE 11 can be produced with a high degree of uniformity. Such coagulation of the fibers may be performed by any of the coagulation media conventionally used for coagulating such spinning solutions. For example, such coagulation medium may be a liquid, a heated gas, or a cool gas depending upon whether the wet-spinning, dry-spinning, or melt-spinning techniques are used for forming the fibers from such spinning solutions.
The advantages of this invention will be apparent when it is compared with the conventtional arrangement in which no guide plate is employed. In such arrangement, known to the prior art, the attempt is made to provide partitioning means centered over the orifices which serve to permit the two different spinning solutions to come together immediately at the orifice.
Because of the extreme difficulty in accurately positioning a partitioning means exactly on the center line of an orifice, particularly with such small orifices as are customarily used in the spinning of synthetic filaments, uniformity from fiber to fiber spun from different orifices of the same spinnerette is substantially impossible of achievement. Also, the resistance to flow throughout the passageway from the spinning tube proper to the spinnerette orifices is considerably lower than the resistance encountered .as the spinning solution flows through the spinnerette orifices with the result that any variations in the relative pressure, flow rate, and other conditions of the two spinning solutions are readily reflected at the junction where both solutions merge, further affecting the relative proportions of the two solutions passing through the spinnerette orifice. This further adds to the ditficulty in effecting a uniform distribution between the two different spinning solutions concurrently extruding through the common orifice thereby adversely affecting the uniformity in quality of the final fibers.
In contrast, where a guide plate 13 is utilized, in accordance with the teachings of this invention, the lower edges of the separating plates between slots 29 and 30 which have the V-shaped edges and the Y-shaped channels 23 in guide plate 13 which coact therewith may be formed in exact dimensions so that when properly aligned, as illustrated in FIGURE 1, the ti-shaped channels 35 which are formed thereby have an exact, predetermined thickness. This exact, predetermined thickness of the two arms of V-shaped channel 35 makes it possible to distribute each of the two dissimilar solutions to the clearances at a given ratio. The resistance to flow which a spinning solution encounters when it passes through the constricted arms of the V-shaped channels 35 may be made sufficiently great by making such clearances sufiiciently small that this resistance to flow may be the major resistance to flow of these solutions along the entire pathway through the spinning head and the spinnerette orifice thus insuring good control of the relative distribution of the two spinning solutions in the fibers being produced.
Thus, all variations in pressure, flow rate, etc. between the two different spinning solutions within slots 29 and 30 and prior thereto are minimized as they pass through the constricted arms of V-shaped channels 35 with the result that the influences of the above-mentioned variations are minimized at the converging point of the two solutions in channel 36 so that the solutions in channel 36 and passing through orifices 21 are constantly maintained in a uniform distribution rate.
As mentioned before, orifices 21 in any given row are substantially tangent to each other at the maximum diameter thereof which occurs in the face of spinnerette Ill which is inside the spinnerette holder. Since these orifices are tangent to each other along the line of the centers of the orifices as best seen in FIGURE 5, which line also is the line where the interface between the two spinning solutions first impinges upon spinnerette 11, the laminar fiow of the two spinning solutions is neatly sliced at such location and flows smoothly down the walls of orifices 21. It will be readily apparent that where the orifices are spaced further apart than the aforesaid distance, liquid flowing down channel 36 upon reaching spinnerette 11 between such orifices would have to move along the back face of spinnerette 11 to reach an orifice thereby disturbing the smooth laminar flow of the solutions in the most critical region, the interface between such solutions. Such disturbance of the smooth laminar flow of the interface in the random manner that would occur from orifice to orifice where the spacing between such orifices is substantially greater than illustrated in FIG. 5, would result in random variations in the distribution of the two components in the final fiber. This variation might be manifest as a variation with time in the filament produced from a single orifice as well as a variation in the filaments produced from orifice to orifice in the same spinnerette.
Referring next to FIGURES 7 through 10, there is illustrated another embodiment of this invention wherein a fine mesh screen 41 is interposed between spinnerette 11 and guide plate 13 of a device which is otherwise identical to that illustrated in FIGURES 1 through 6. The fine mesh screen serves to apply a small turbulence to each of the solutions flowing in laminar flow down channel 36 to orifices 21, particularly at the interface of such solutions, so as to produce a slight blending of the two components at the interface thereof.
As seen in FIGURE 11, which illustrates a fiber produced utilizing the method and apparatus of FIGURES 1 through 6, it will be seen that the two components there of are quite sharply delineated at the interface therebetween. Since the two components have different shrinkages, in order to produce a curly or crimped fiber, it will be realized that a considerable strain is set up at the interface between the two dissimilar materials. Under certain circumstances it is possible that this strain could exceed the forces holding the two materials together causing a splitting of the bi-component filament into separate portions.
As seen in FIGURE 12, which illustrates fibers made utilizing the method and apparatus of FIGURES 7 through 10, it will be seen that there is a slight blending of the two materials particularly at the interface therebetween. This serves to reduce the strain caused by the differential shrinkage of the two materials and serves to reduce the likelihood of a separation of the two components by spreading the strain throughout a thicker or larger interfacial zone. The degree of interfacial mixing achieved is a function of the mesh or fineness of the screen 41 located at the entrance to orifices 21.
It is to be noted that too coarse a screen will not yield the desired degree of intermingling of the two components or will detract from the uniformity of the distribution of the components within the fiber while if the screen is too fine, accumulation of foreign matter thereon or the fineness of the screen itself will increase the resistance to flow of the highly viscous spinning solutions used with the result that operation may become impossible. For these reasons, the mesh of the screen is very important and is preferably from 115 to 350 mesh. The material of which the screen is composed is unimportant provided it is inert with respect to the substances with which it comes in contact. For example, metal, glass and plastic materials may be used.
Example 1 Using the device of FIGURES 1 through 6 connected to a couple of metering pumps, equal amounts of aqueous calcium thiocyanate solutions of two different copolymers each composed mainly of acrylonitrile were extruded into a coagulating bath containing 8% calcium thiocyanate and kept at 0 C. The number of holes in the spinnerette was 100 and each hole was 0.09 mm. in diameter. One of the solutions was that composed of 10 parts of an acrylonitrile copolymer consisting of 90% of acrylonitrile, of vinyl acetate and 5% of vinyl pyridine (the value as measured with dimethyl formamide used as solvent is 0.21) dissolved in 90 parts of a 50% aqueous solution of calcium thiocyanate. The other spinning solution was a solution of parts of an acrylonitrile copolymer comprising 85 of acrylonitrile, 7.5% of vinyl acetate, and 7.5% of vinyl pyridine (the [7 value as measured with dimetthyl formamide used as solvent is 0.21) dissolved in 90 parts of a 50% aqueous solution of calcium thiocyanate. After spinning, the gelled filaments were washed in water and drawn in boiling water to 800% the initial length. The filaments were dried to a moisture content of less than 3% in a highly moist atmosphere at a dry-bulb temperature of 105 C. The filaments were further treated in a relaxed state in saturated water vapor at 115 C. for 10 minutes. After 20 minutes drying at C., the filaments had substan tially uniform coily three-dimensional crimps. The filaments had the following properties.
Fineness denier 3.03 Strength g./d. 3.45 Elongation percent 32.5 Number of cr-imps 18.5 Crimping ratio 12.3 Crimp elasticity 85.5
(Number of crimps, crimping ratio, and crimp elasticity were determined by ES L-l024.)
FIGURE 11 shows a cross section of the filament obtained when carbon black had been added to the abovementioned spinning solution containing an acrylonitrile copolymer composed of acrylonitrile, 5% of vinyl acetate and 5% of vinyl pyridine. The shadded portion of FIGURE 11 represents the copolymer consisting of 90% of acrylonitrile, 5% of vinyl acetate and 5% of vinyl pyridine. Thus, it is apparent that the two components are uniformly conjugated in a halfand-half relation for all filaments.
Example 2 Using the device of FIGURES 1 through 6 connected to a couple of metering pumps. Equal amounts of aqueous-sodium thiocyanate solutions of two dissimilar oopolymers of acrylonitrile with methyl methacrylate were extruded into a coagulating bath containing 8% of sodium thiocyanate at 0 C. The spinnerette employed in this example had 200 holes, each being 0.10 mm. in diameter. One of the spinning solutions was a solution of 10 parts of an acrylonitrile copolymer composed of 93% of acrylonitrile and 7% of methyl methacrylate ([1 value as measured with dimethyl formamide used as solvent was 0.22) dissolved in a 50% solution of sodium thiocyanate. The other solution was a solution of 10 pants of an acrylonitrile oopolymer consisting of 91% of acrylonitrile and 9% of methyl methacrylate (the value as measured with dimethyl formamide used as solvent was 0.23) dissolved in 90 parts of a 50% aqueous solution of sodium thiocyanate. After spinning, the gel filaments were washed with water and stretched in boiling water to 800% of the initial length. The filaments were dried to a moisture content of less than 2% in a highly humid atmosphere at a dry-bulb temperature of C. and wet-bulb temperature of 65 C. The filaments were further processed in a relaxed condition at C. in saturated water vapor for 10 minutes. After 20 minutes drying at 80 C., the filaments had substantially uniform three-dimensiorral coily crimps.
The test results for the filaments of this example are as follows.
Fineness denier 2.95
Strength g./d. 3.95
Elongation "percent" 30.5
Number of crimps 15.3
Crimping ratio 19.3
Crimp elasticity 86.9
Example 3 Using the device of FIGURES 7 through 10 connected with a couple of metering pumps, equal amounts of aqueous calcium thiocyanate solutions of two different acrylonitrile polymers were extruded into a coagulating bath containing 8% of calcium thiocyanate. The spinnerette employed in this example had 100 holes, each being 0.15 mm. in diameter. The screen intenposed between guide plate and spinnerette was No. 200 wire netting of stainless steel. One of the spinning solutions was a solution of 9 parts of a homopolymer of acrylonitrile (the value as measured with dimethyl formamide used as a solvent was 0.21) dissolved in 91 parts of a 50% aqueous solution of calcium thiocyanate. The other spinning solution was a solution of 9 parts of an acrylonitrile copolymer composed of 90% of crylonitrile and of methyl acrylate (the [1 value as measured with dimethyl formamide used as solvent was 0.21) dissolved in 91 parts of a 50% aqueous solution of calcium thiocyanate. After spinning, the gel filaments were washed in water and stretched in boiling water to 800% the initial length. The filaments were dried to a moisture content of less than 2% in a highly moist atmosphere at a dry-bulb temperature of 110 C. and a wet bulb temperature of 70 C. The resultant filaments had substantially uniform three-dimensional coily crimps. Test results are summarized below.
Fineness denier 10.5 Strength -g./d. 2.46 Elongation percent 30.6 Number of crimps 12.8 Crimping ratio 12.4 Crimp elasticity 80.2
In FIGURE 12 are presented cross sectional views of the filaments obtained when carbon black had been added to the above-mentioned spinning solution containing a homopolymer of acrylonitrile, the shaded portions of the cross-sections representing the said homopolymer. It will be noted in FIGURE 12 that the reduced concentration of carbon black around the interfacial regions on this cross-section indicates how the two components of this example are intermingled. Some samples of these filaments were subjected to repeated flexing cycles, and others were made into staple and spun into threads. In either case, no cleavage of the two components was observed.
It is thus seen that there has been provided herein a novel method and apparatus for the production of multicomponent fibers of high uniformity which may be used for producing fibers having permanent crimp. While this method and apparatus have been illustrated and described in terms of two specific embodiments, it is to be understood that the invention is not limited to these details except insofar as they appear in the subjoined claims.
1. In the method of spinning a composite fiber by extruding a plurality of difierent spinning solutions concurrently through a common orifice into a coagulating medium, the improvement comprising flowing such solutions separately as thin confined films moving in laminar flow towards a juncture thereof; flowing such solutions from such juncture toward said orifice as a plurality of thin films moving in laminar fiow with the adjacent faces of such films in non-mixing interfacial contact; and extruding such solutions continuously and concurrently through said orifice in side-by-side relationship into a suitable coagulating medium.
2. A method as defined in claim 1 wherein said thin confined films flow toward the juncture thereof and meet at an acute angle to each other.
3. A method as defined in claim 1 including imparting a slight turbulence to at least the interfacial regions of said films as said spinning solutions enter said orifices whereby said solutions are slightly intermixed at their interfacial regions.
4. Apparatus for spinning a composite fiber by concurrent extrusion of a plurality of different spinning solutions through a common orifice into a coagulating medium comprising a spinnerette holder;
means for separately supplying a plurality of spinning solutions to said spinnerette holder;
a spinnerette mounted in said spinnerette holder, said spinnerette having therein an orifice whose maximum diameter is adjacent the face thereof within said spinnerette holder; and
means within said spinnerette holder defining a narrow channel for each said spinning solution, said narrow channels merging into a common narrow channel having a width substantially equal to the maximum diameter of said orifice and communicating with said orifice.
5. Apparatus as defined in claim 4 wherein said narrow channels intersect at an acute angle where they merge into said common narrow channel.
6. Apparatus as defined in claim 4 including a screen interposed between the outlet of said common channel and said orifice.
7. Apparatus for simultaneous spinning of a plurality of composite fibers by concurrent extrusion of a pair of different spinning solutions through a plurality of common orifices into a coagulating medium comprising a spinnerette holder;
a spinnerette mounted in said holder, said spinnerette having therein a plurality of orifices each of which has its maximum diameter at the face of the spinnerette within said holder, said orifices being disposed in at least one row with adjacent orifices in such row located on a center-to-center spacing substantially equal to the maximum diameter of said orifices whereby each of said orifices are substantially tangent to their adjacent orifices at their maximum diameters; and
guide means within said spinnerette holder having therein a channel of width substantially equal to the maximum diameter of said orifices for guiding said pair of spinning solutions in interfacial contact and in laminar flow towards said row of orifices.
8. Apparatus as defined in claim 7 wherein said guide means is also provided with a pair of narrow channels, one for each of said pair of spinning solutions, which meet at an acute angle where such narrow channels merge into said aforementioned channel.
9. Apparatus as defined in claim 7 including a screen interposed between said spinnerette and said guide means.
10. Apparatus as defined in claim 7 wherein said guide means comprises a guide plate provided with a Y-shaped slot, the base of said slot being substantially the same width as the maximum diameter of said orifices, said slot being operatively associated with said row of orifices and means for separately feeding each of said pair of spinning solutions through the upper arms of said Y-shaped slot in thin confined films moving in laminar flow toward the base of said slot.
References Cited by the Examiner UNITED STATES PATENTS 2,386,173 10/45 Kulp et a1 188 3,006,028 10/ 61 Calhoun l88 3,039,173 6/62 Mehler et al 264-171 FOREIGN PATENTS 760,179 10/56 Great Britain. 954,274 4/64 Japan.
ALEXANDER H. BRODMERKEL, Primary Examiner.
WILLIAM J. STEPHENSON, MORRIS LIEBMAN,