US2439814A - Crimped artificial filament - Google Patents

Description

April 20, 1948. w. A. SISSON 2,439,814

CRIMPED ARTIFICIAL FILMIENT Filed May 13, 1945 INVENTOR WA YNE A. S/SSON BY W4 m ATTORNEY.

shown in the ap lication Patented Apr. 20, 1948 2,439,814 CRIMPED ARTIFICIAL FIIAMEN'I Wayne A. Sisson, Silverslde, Del.,

American Viscose Corporation, Wilmingto assirnor to Del., a corporation of Delaware Application May 13, 1943, Serial No. 486.773 6 Claims. (CI. 28-82) This invention relates to novel filaments of composite character, and particularly to filamerits of this character having a substantially permanent crimp. The process hereinafter described is claimed application Serial No. 1945.

In order to make filaments of this invention, two or more diiierent spinning materials are spun into filaments in such a manner that the individual filaments comprise two or more longitudinal sections joined in side by side relationship. This, in its most elementary aspect, may be accomplished byarranging an orifice in one splnneret in close juxtaposition to that in another, feeding the different spinning materials to them and withdrawing the single filament produced by the conversion to a plastic condition in the setting medium of the single-liquid stream resulting from the joining of the two streams of material issuing from the orifices. By similarly arranging in proximity three or more orifices in a corresponding number of spinnerets which may be fed a corresponding number of different spinning materials, a correspondingly more complex conjugate filament results. Other arrangements may be utilized to produce the filaments, it being necessary only that the separate streams of the difierent spinning materials be united at the point of entrance into the setting or coagulating medium, or shortly before or after reaching this point.

In accordance with one such arrangement of Kulp et al., Serial No. 486,774, filed on even date herewith, which has since issued as Patent 2,386,173, dated October 2, 1945, two or more filament-forming materials of different properties, in a fused or plasticized state or in the form of solutions thereof, are extruded in separate or only partially intermingled phases through a common orifice or a plurality thereof, where they are joined together in eccentric or side by side relation, into a setting medium which may be either gaseous or liquid and may function either by a coolin precipitating or evaporative effect to produce unitary filaments in each of which the different materials form separate portions of the body of the filament.

A certain amount of mixing is permissible provided only that the mixing does not become so great as to render the final filament homogeneous in cross-section. Preferably, mixing between the two streams of filament-forming material occurs at the boundary of the juncture to the 625,645, filed October 30,

in my copending divisional 2 extent needed to obtain a strong bond in the final filaments.

Any of the filament-forming materials or solutions including viscoses, proteins, such as caseins and soya bean proteins, cellulose derivatives such as cellulose acetate and ethyl celluloses, and resins such as nylons, the vinyl resins, especially the copolymers of vinyl chloride and vinyl acetate and the vinylidene halides, may be employed. When different cellulose xanthates or viscoses are used, they may differ as to either age, cellulose content, sodium hydroxide content, carbon disulphide content, as to the type of cellulose from which they are made, such as wood pulp or cotton pulp, or as to any two or more of these factors. When other cellulose derivatives, such as the esters or ethers, are used they or their solutions may differ as to viscosity, cellulose content, or as to degree of polymerization or substitution of the cellulose chains therein. When resin solutions are used, the solutions may difier as to kind of resin, viscosity, and the degree of polymerization of the resin. Two spinning materials of different classes may be combined, such as a protein with a viscose, a protein with a cellulose acetate, or a cellulose acetate with a vinyl resin. It is only necessary that the materials in the form employed (fused or in solution) do not mutually precipitate each other and that they adhere together in the final filaments.

The filaments may be extruded into either a liquid or gaseous setting or precipitating medium depending upon the solutions that are used. For instance, viscose solutions may be extruded into an acid precipitating bath and other cellulose derivatives and resins or their solutions may be extruded into either a liquid or a gaseous medium.

After production of the filaments by the conversion to a plastic condition in the setting medium of the dual-material streams, they are subjected to an after-stretch while plasticized or not, thereafter relaxed in a plasticized condition and the plasticizer is removed while in relaxed condition to set the crimp therein. The plastlcizer employed depends on the materials of which the filaments are composed. Water, whether hot or cold, is adequate for regenerated cellulose. Heat or swelling agents may be employed with thermoplastics such as the cellulose esters and ethers, vinyl resins, nylons, and the like. One particularly advantageous method of producing crimped filaments from thermoplastic components is to use two such components which have different shrinkage temperatures or which possible without 2,439,814 I .z s

Figure 1 shows the filaments in cross-section,

and Figure 2 shows the crimpiness of the fila- 1 ments.

- While the description which follows hereinafter more completely illustrates the invention asap-* plied to composite regenerated cellulose filaments, it is to be understood that it is orally to filaments of any component materials, at least one of the components of which is plasticizable. Generally stated, the process of making I the filaments of the invention comprises stretching the composite filament while plasticized or while at least one of its components is plasticized, subsequently relaxing and, if not already at least partiallyplasticized, plasticizing at least one or more or all of the components of the filament, and then restoring the filament to unplasticized condition while maintaining it under relaxation.

When viscose solutions are spun, any conventional spinning arrangement may be used for coagulating, collecting and wet-processing the filaments. For example, the filaments proceeding from the coagulating bath may be guided by a series of godets or rotating guides to a collecting device in the form of a bobbin, spinning bucket, or a twisting device. If desired, a certain amount of stretch may be imparted to the filaments as they proceed between one or more pairs of the godets by virtue of differences in linear peripheral speeds thereof. The collected filament package is subjected to the conventional wet-processing treatments, such as washing, desulfurizing, bleaching, soaping, dressing, and finally drying. Alternatively, the filaments may be made by a continuous process in which they travel continuously, such as in the form of helices, through subsequent liquid-treating baths directly from the coagulating or the stretching bath if the latter is used, in which arrangement, the filaments as finally collected are in a dry condition.

The composite filaments are subjected to an after-stretching which may be performed while the filaments are still in a wet or plasticized condition as they come from any stage of the liquid processes to which the artificial filaments are subjected, generally without drying, after formation or production by spinning into the setting medium. The after-stretching maybe performed upon the filaments after the final drying stage of after-treatment. The after-stretching may then be performed on the dry filaments, but preferably, the filaments are wetted before being subject,ed to the after-stretching procedure. The

stretching should besuiilcient to go beyond the elastic limit of at least one component (and preferably beyond that of all components if this is rupture) of the filaments under the stretching (that is, the claswet or thedry condition). In

the conditions of tic limit for the terms of the percentage elongation. a stretch of from about'20 to 50% and preferably of to 50% of the original length is generally suitable. In any event, the percentage of stretching that can be imparted to the filaments depends upon relaxed and allowed applicable geni by performing the V For the purposes the extensibilities of the component portions of the individual filaments, that component having the lower extensibility controlling the limit of elongation before rupture.

After the stretching, the filaments are allowed to relax whlle wet or plastic and to dry in the relaxed condition. If the after-stretching is performed on the dry filaments, they are wetted and to dry while in the relaxed condition.

The after-stretching procedure, whether peror dry, imparts a decided crimp of permanent character to the fila- When the filaments before being sub- Generally, a much greater improvement in crimp or degree of crimpiness is obtained after-stretching while the filaments are wet. A

The difference in viscoses that can be used may be comprised of any one or more of several factorsincluding the type of pulp (whether cotton or wood), salt test (old or young); percentage sodium hydroxide, percentage cellulose, percentage carbon disulfide, percentage sulfite, viscosity, surface tension, as well as the presence or absence of pigments,- delustrants, and so forth.

of obtaining a crimp, difier- 'ences in the viscoses which manifest themselves in differences in shrinkage in the final product are of the greatest importance. 'To obtain a crimp; it is sufficient to utilize viscoses made of diiferent pulp, especially of wood pulp with cotton pulp; viscoses of different salt tests or ages,

percentages of cellulose, different percentages of carbon disulfide, diiferent amounts salt test and/or as to any one or more of the other factors specified. By taking into consideration the differences in shrinkage characteristics of any two viscoses, it is possible to combine predetermined qualities into the two components of the filaments and obtain any desired crimpiness in the product ranging from 5 to '50 or more crimps per inch. Thus, by combining a viscose which shOWs relatively little shrinkage when subjected to the conditions under which the processing of the composite filaments is to be performed with a viscose having a high degree of shrinkage under such conditions, an extremely crimpy filament is obtained. Conversely, if the shrinkage characteristics of the two component viscoses are very little different when subjected to the processing conditions as individual filaments, composite filaments made of such a pair of viscoses would show relatively little crimping. Thus, simply by the selection of the two viscoses from which the composite filaments are to be produced, any, desired predetermined crimpiness can be obtained in the final composite filament. This makes it possible to produce tailor-made" crimped continuous filaments and staple fibers.

Referring to Figures 1 and 2 of the drawing in which views are shown of filaments made in accordance with the invention, reference character 2 indicates a filament generally and reference characters 3 and 4 indicate the component portions of the filament which are constituted of different materials. In Figure 2 of the drawing in which the crimp of the filament is shown, reference character 5 indicates one bend of the crimp. Reference character 4 indicates the portion of the filament that is made of the material covery and reference portion rial having the tion than that of the agssaeu.

having the lesser tendency to shrink or; less recharacter 3: indicates the the crimp is actually of a three-dimensional character (that is, random in three shows the filament in a single plane.

The individual filaments producedin ance with this invention have a unitary structure having a cross-section at all points of the filathe crimps extend or lie at ment length which comprises two or rnore sub-' stantially distinct areas each of whichhas a difdimensions) and that Figure 2 v of thefpres nt inv "test outlined in 2,231,099. Thus. the composite filaments and sta le fibers excellence'j (that is from about 60 to 100%,) when measured by the crimp recovery from stretch" of the-present invention do not appreciably lose ferent composition or state ofphy l assresaothersand at least one of which is eccentrically the filament cross-section. -.The components of the composite fibers-exhibit thereindifi'erences in,

extensibilities, strength,-

shrinkage, swelling, 1 orientations, dye absorptions, chemical-reactivity,

crenulation, and they may sometimes show different skin thicknesses which is readily observ-- able as a differential dye absorption phenomenon when they are stained with certain dyes.

The crimped filament takes the form of .a regular or irregular helical coil which may reverse itself in direction at more or less frequent intervals of regular or irregular occurrence, thedisposed with respectto used by adiusting'the ning material their crimp during the ordinary conditions of wear in either of which temperaturesrangins from the neighborhood of the freezing point and the boiling "point of water ricat'ed products made are encountered. Fabfrom these filaments and fibers thus have properties which may .be made to approach those of spects. Such products are. claimed in my'jcopending application Serial No. 554,549,- illed September 16, 1944.

While it is preferred that the unitary filaments comprise approximately equal portions of. the different types of material, various-proportionsof the different types-of spinning solutions may be v v pumps to control the pro.-" .portionate amounts ofthe diiferent types of spinthat are delivered to fornia single filament.

g It is to be understood that changeshndjvaria .tions may be made. without spirit and scope of the invention as defined by departing from the theappended claims.

I claim: .1. An artificial filaments two components ofmaterials :Ioined side by side eccentric components of the filament-following 5 a helical path about the longitudinal axis of the filaments, which path may reverse itself at more or less frequent irregular or regular intervals. Thus, a three-dimensional crimp with the crimps out of phase is present in the composite filaments.-

The individual composite filaments produced in accordance with this invention in their state of normalcy are characterized by a stabilized condition having aninherent distortion which imparts a permanently recoverable crimp. The only condition under which it loses its crimp, and in this case the loss is temporary, is that prevailing when the crimped filament is wetted or otherwise plasticized and caused to dry while under a tension. It can be repeatedly wet or otherwise plasticized and dried without an appreciable loss in crimpiness as long as it is permitted to dry in a relaxed condition. If dried under tension, the crimp can be recovered merely by wetting or otherwise plasticized and drying while relaxed.

No completely satisfactory tests have been devised to evaluate the degree of permanency of a crimp. However. the crimped composite filaments of this invention have been found to possess a crimp retentivity ranging from about 60% up to a value approaching 100% when tested in accordance with the procedure outlined in the Hardy et al. Patent 2,287,099, issued June 23, 1942. Individual filaments when subjected to that test, not merely after a single immersion but after as many as 20 or more immersions, have been found to show crimp retentivities as high as substantially 100% and relatively few of the filaments made in accordance with this invention have been found to have crimp retentivities as low as 60%. The crimp retentivity test as outlined in Patent 2,287,099 is performed .in water at 60 C. It has been found that for the composite filaments of this invention, crimp retentivity is fully as high when cold or boiling water is used in the test. Thus,

' filament reversibly convertible by plasticization .ing components. each or the portion of its peripheral surface disposed outsideponents being formed the entire length of the portions of the materials making u the adjointhe periphery of each other component throughout the entire length of the filament. said comfrom differing materials and having diiferent characteristics rendering the and setting thereof between an inherent crimped condition obtainable by setting in relaxed condition and astraight condition obtainable by setting under tension, said characteristics including different orientations with at least one component stretched-beyond its elastic limit resulting from stretching the compostie filament after production beyond the elastic limit of at least one of its components.

2. A dry substantially straight artificial filament comprising at least two components of materials having different shrinkage characteristics including diiferent orientations with at least one component stretched beyond its elastic limit resulting from stretching the com-' posite filament after production beyond the elastic limit of at least one of its components, said components being formed from differing materials and joined side by side the entire length of the filaments by intermingled portions of the materials making up the adjoining components, each of the components having a portion of its peripheral surface disposed outside the periphery of each other component throughout the entire length of the filament, said filament having the potential capacity to become crimped on being treated with a shrinkage agent.

3. An artificial filament having a plurality of crimps lying at random in three dimensions and comprising at least two components of materials joined side by side the entire length of the filaments by intermingled portions of the materials making up the adjoining components, said comthe composite filaments ponents being formed from differing materials tion show a. corresponding.

the above mentioned Patent natural woolin some r'ecomprising at least filament by intermingled components having a face disposed outside having difi'erent degrees of orientation with at least one component stretched beyond its elastic limit resulting from stretching the composite filament after 01' at least one of its cmponents,'each oi the components having a portion of its peripheral surface outside the periphery of each other component throughout the entire length or the filament.

- 4. An artificial filament comprising at least two components or regenerated cellulose Joined side by side the entire length of the filament by intermingled portionsot the materials making up the adjoining components, each of the components having a portion. of. its peripheral surthe periphery 01' each other component throughout the entire length of the filament. said components being formed from ditfering-materials and having different shrinkage characteristics rendering the filaments reversibly convertible by plasticization and setting thereof between. aninherent crimped condition obtainable by setting in relaxed condition and a straight condition obtainable by setting under tension, said characteristics including different orientations with at least one component stretched beyond its elastic limit resulting from stretching the composite filament after production beyond the elastic limit of at least one of its components.

5. A dry substantially straight artificial filament comprising at least two components of regenerated cellulose having difierent shrinkage characteristics with at least one component stretched beyond its elastic limit as a result of stretching the composite filament after production beyond the elastic limit of at least one oi its components, the components being formed from difi'ering materials and joined side by side the entire length of the filament by intermingled portions of the materials making up the adjoining components, each of the components having a portion of its peripheral surface disposed outside the periphery of each other component throughout the entire length of the filament, said filament having the potential capacity to become crimped upon being treated with water.

production beyond the elastic limitfile of this patent:

UNITED STATES PATENTS Number Name Date 2,238,694 Graves Apr. 15, 1941 2,297,585 Shepherd Sept. 29, 1942 1,611,001 Cross Dec. 14, 1926 1,867,298 Zart et al. July 12, 1932 2,209,919 Herrmann July 30, 1940 2,310,785 Herrmann Feb. 9, 1943 2,328,074 Hunter Aug. 31, 1943 FOREIGNPA'I'ENTS Number Country Date 837,555 France Nov. 12, 1938 797,779 France Feb. 24, 1936 132,043 Japan Oct. 11, 1939 51,807 Netherlands I Sept. 16, 1941 OTHER REFERENCES Cleaning and Dyeing oi Celanese and Rayon,

throughout theentire length of the 6. An artificial filament having a plurality of crimps lying at random in three dimensions comprising two components of regenerated cellulose difierently oriented with at least one component stretched beyond its elastic limit as a result of stretching the composite filament after production beyond the elastic limit 01' at least one 0!. its components, the components being formed from diii'ering materials and Joined side byside the entire length thereof by intermingled portions of the materials making up the adjoining components, each of the components having a portion oi. its peripheral surface disposed outside the ,periphery of each other component filament.

( WAYNE A. SISSON.

REFERENCES CITED The following references are of record in the L. E. Foster. Copyright 1929. (Copy in Scientific Library.)

Handbook of Plastics, Simonds and Ellis,

copyright 1943.

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