Patented Oct. 1, 1946 ' 2,408,381 ~ ' ’ UNITED _ STATES PATENT *oF'FicE 2,408,381 I, __ ‘7 V f, tREVSILIENT FILAMENTS I 7 Frederick G. Dodge, La Vale, MtL, assignor to 001- , l anese Corporation of America; a corporation of Delaware . No Drawing. Application October 6,1943, Serial No.‘ 505,165 7 Claims. (Cl. 8-431) 2 removed from the ?laments, they are then im-‘ mersed in water at an elevated temperature. The This invention relates to’ the preparation of arti?cial ?laments having a basis of cellulose acetate, or other organic derivative of cellulose, ?laments are maintained in the Water bath for a which ?laments are substantially permanently orim'ped and highly resilient, and which possess a 'An object of my invention is to provide a proc short time after which the Water is removed and the treated ?laments are dried with heated air. This treatment effects a marked change'in the character of the ?laments In place of their ess for the treatment of arti?cial ?laments hav-' ‘ing ‘a basis of cellulose acetate or other organic ments are 'now permanently crimped or crinkled voluminous or lofty structure. , ‘ originally smooth and straight structure, .the ?la derivative of cellulose whereby said ?laments may 10 and possess a full and elastic hand ‘substantially similar to that possessed by wool. Furthermore, ' I ' be permanently crimped. the ?laments are far more resilient than prior .to treatment and recover their original voluminous ' Another object of my invention is to provide a process tor the treatment of cellulose acetate or other organic derivative of cellulose ?lamentary structure even after the prolonged application of materials to render the latter more resilient and 15 to impart thereto a voluminous structure. , Other objects of my‘invention will appear here pressure. ~ , . Any suitable liquid medium having a softening action on the cellulose acetate ?laments may be . employed. Examples of such liquids are aqueous solutions of ethyl alcohol, containing from 50 to Filaments having a basis of cellulose acetate or other organic derivative of ‘cellulose in staple 20 95.5%‘ of vthe alcohol, aqueous, solutions of ace tone containing from 20 to 80% of acetone, and ?berform have been'found to possess excellent aqueous solutions of acetone containing ethyl insulating characteristics when employed in the and/or methyl‘ alcohol, for example, those solu manufacture of comforters, sleeping bags and like tions containing from 10% to 40% of acetone and articles. Continuous arti?cial ?laments having a basis of cellulose acetate or other organic deriva 25 from 10 to 50% of ethyl and/or methyl alcohol. Solutionscontaining ethyl ,alcohol, acetone or tive of cellulose differ from materials such as cot methyl alcohol together with organic ' liquids ton and wool in that the arti?cial ?laments are which do not exert any softeningor swelling ac relatively smooth. They do not possess a crimped inafter from the followingdetailed description. or crinkled structure, such as‘vthat found in naturally, occurring ?bers such as wool, which 30 tion on the cellulose acetate ?laments suchvyas benzol and‘toluol, xylol or. paraf?nichydrocar bons may also be employed. Preferably, We em ploy aqueous solutions of . ethyl alcohol contain quently, when the ordinary arti?cial ?laments ing from 7.0 to 90% by volume of the alcoholas the. treating ‘medium.’ The alcoholic solutions [having a basis of vcellulose acetate or other organic derivative ‘of cellulose are subjected to prolonged CC may beat a temperature of from 65 to 110° F. during treatment and the ?laments may be main pressure, ‘as, for example, in a sleeping bag, they structure is largely responsible for the character? isticv hand or fullness of said materials. ‘Conse I tend to become matted and upon release of the ' tained therein for from‘ 5 to 60 seconds. _When pr'essure'do ‘not fully'return, to their original employing aqueous solutions of ethyl alcohol, the temperature is preferably about 90°F. and the voluminous state.‘ This matting causes the dead air. spaces in said arti?cial ‘?lamentary mate 40 ?laments are usually maintained therein for about 30 seconds. Following this treatment, the excess rials to be reduced in volume and the latter grad liquid is removed in any convenient manner, such ually lose some of their insulating properties which, of course, is a'de?nite‘ disadvantage which The moist ?laments are removed from the cen tends seriously to restricttheir usefulness. as, for examplecentrifuging. ' ‘ ' v ' ' ‘~ ‘I’ have now discovered,however, that arti?cial 45 trifuge after the solvent treatment and are then placed in a water bath at a temperature of 60 to ?lamentary‘ materials having a basis of cellulose acetatev or ‘other organic derivative of cellulose, and particularly ?laments in staple ?ber form, 212° F.", preferably about‘ 150 to 160° F. for‘ 1 to _5 seconds. ‘Atthefend of this period the ?laments , may be treated so as to impart a substantially are removed from the water bath, centrifuged I permanent crimped or crinkled structure thereto. 50 to remove as much water as possible, and are then dried with hot air. Any‘ ‘convenient method of In ‘accordance with the novel process of my in vention, ?lamentary materials having a‘ basis ‘of . drying is suitable. The ?laments may vbe dried, for example; by being placed upon screens ‘or cellulose acetate are immersedin a liquid medium racks and entered into a chamber through which having at least a softening action on'the cellulose acetate ?1am'ents,"and, after the excess liquid-is 55 hot air is 'circulated,'or the ?lamentsmay ‘be. 2,408,381 4 3 therein without departing from the spirit of my invention. The expression “swelling agent” as employed in placed in a rotary drier in which they are tumbled about while hot air passes therethrough. During the drying operation, the air may be at a temper ature of 68 to 300° F. The ?laments may be treated while in a con (.1 tinuous ?lamentary form but preferably they are converted into‘ relatively short‘ staplelengths, for example from 3 to 6 inches in length, beforebeing. treated. The ?laments may be prepared in any con- Having described my invention, what I desire to secure by Letters Patent is: 1. Process for the production of voluminous, venient manner well known to the art suchas by permanently crimped arti?cial staple ?bers, which comprises. immersing relaxed, unstretched andv una-ssoc‘ratedv dry-spun staple ?bers, having dry-spinning or wet-spinning operations; Pref erably, we employ ?lamentshav-ing; a basis of an. organic derivative of cellulose which. aresprepared by dry-spinning operations. A particularly valu able product is obtained when I employ those dry the appended claims is to be construed as includ ing within its scope substances which not only have a swelling effect on the organic derivative of cellulose but which may‘ also‘ have a, solvent action thereon. 15 a basis of arr. organic derivative of cellulose and prepared. from ?laments spun without any ten sion being exerted thereon, in an aqueous liquid medium containing a water-soluble swelling agent having at least a softening action on the organic tion as, for example, those ?laments prepared" in accordance with the process of U. S. Patent No. 20 derivative of cellulose, removing excess liquid spun ?laments which are not subjected to any tension or draw-down during the spinning opera 2,290,929‘. from the. staple ?bers,_ immersing. thevstaple. ?bers The ?laments; may be. of; any con venient; denier; excellent results being achieved with ?lamentsiof 1.5 to 30. denien; In. order further to illustrate my invention but Without being limited. thereto, the following ex. 25 ample is given. Example inv water at atemperature of about. 150 to 1:609 B1,, removing the water from. the staple: ?bers and drying the staple. ?bers, whereby voluminous, permanently crimped staple. ?bers are produced. 2. Process for the production of voluminous, permanently crimped. arti?cial. staple. ?bers, which. comprises immersing relaxed, unstretched and unassociated dry-spun staple fibers, having Cellulose acetate.- ?laments. are: dry-spun with. out. tension or: draw-down». employing. a' solution of 30 a basis of cellulose. acetate. and prepared from ?laments spun without any tension. being ex cellulose acetate. in acetone containing: about 25 %. erted. thereon, in. an. aqueous liquid. medium. con by weight oiicellulose; acetate. and: 7 5% by weight taining a water-soluble swellingv agent having of 95/5. acetone/water; The ?laments. are spun so as.to. be. approximately 6 denier per ?lament". The continuous ?laments are then cut into staple ?ber' in‘ any‘ convenient manner in which the ?bersarefrom 3.to. Binchesinl'ength. at. least a. softening. action. on. the cellulose- ace. tate, removing. excess. liquid from the staple?bers, immersing the. staple. ?bers in water at. a. tem perature of about. 150. to. 160?’ F., removing; the water from the staple ?bers and drying thestaple After‘ beingv suitably opened» and loosened up, ?bers; whereby voluminous, permanently crimped the) ?bers, in. the formv of a bundle, are‘ dipped staple ?bers are. produced; into a solution containing 80% by volume of com 40 3. Process for, the production of». voluminous; pletelydenatured ethanol‘ and’ 20%1 by volume of permanently crimped arti?cial- staple; ?bers; which comprises immersing relaxed, unstre-tched and. unassociatedl dry-spun staple: ?bers, having water, maintained at 90° F., for 30lsecond‘s; The treated ?bers are removed from thesolution and the- excess liquid‘ is removed.- by centrifuging. From the. centrifuge- the. ?bers are placed in a water bath at a- temperature» of 1-5'0- to» 1360‘? FL and held therein for about 5 seconds‘. After be ing removed from the water‘ bath, the fibers are a basis of. cellulose. acetate. and prepared. from ?laments. spun. without. any tension. being. exerted thereon, containing from 70. to 90%. by volume of‘ ethyl’ alcohol, removing excess liquid vfrom the staple ?bers,v immersing the staple ?bers in centrifuged again- to remove as‘ much’ Water as possible; and are dried in- a rotary drier with‘ air ' water at..a. temperature. ofv about 150. to. 160° F., removing; the water from the staple ?bers, and at about 200°‘ F; The staple ?ber treated ‘ini'thi's drying. the staple ?bers, whereby voluminous; manner" is observed‘ to have lost the soft and typical hand- of cellulose acetate" ?bers and now possesses a- harsh, voluminous and- resilient hand permanently crimped staplev ?bers are produced». 4... Process. for the. production‘ of voluminous; greatly resembling that of" wool; The?bersare substantially permanently crimped and‘even' after being subjected to an appreciable pressure fora considerable period of‘ time,,.the ?bers resume their. original lofty character and form when 60 the. pressure isremoved. ‘ ' While. our invention. hasbeenmore particularly described in connection with the. treatment of arti?cial ?laments. having, a.v basis. of cellulose acetate, it may be. employed in connection with. thetreatment. ofI ?laments haying ab'asisoflotherl organic. derivatives of. cellulose. for example, cela Iul'ose, esters such as. cellulose, propionate ‘and. col lul‘ose. butyrat’e, mixed esters such as. cellulose acetate-propionate and cellulose. acetateebutyr ate, and cellulose ethers. such as ethyl‘ cellulose andbenzyl cellulose. It is to be understood that. the foregoing de.- ' tailed. description is. given. merely byway of ‘illus permanently crimped arti?cial;v staple ?bers; which. comprises: immersing, relaxed, unstretchecl and unassociated. dry-spun. staple. ?bers, having a basis. of; cellulose acetate and- prepared: from ?laments spun with-outrany tension‘ being exerted thereon, containing from 7.0 to 90% volume of. ethyl‘ alcohol: for, from“. 5. to '60v seconds, re moving excess.- liquid: from’ the. staple ?bers; im~ mersing the staple- ?bers in water at.-.a'~.tempe1r ature of about 150F139 1.60%‘ for‘froirr 1 to: 5 65 seconds,. removing. the. water from the. staple ?bers: anddry-ing the staple‘?lbersh whereby; vole uminous, permanently crimped staple ?bers. are produced». I > ' ' 5-. Process. for: the- production 0st voluminous; 70 permanently crimped; arti?cial. staple: ?bers; which. comprises immersing, relaxed" unstretched and‘unassociated' dry-spurt staple ?bers, having a basis ofv cellulose acetate-.- and prepared‘ from ?laments. spun- without . any tension being: exerted‘ tration. and that» many variations may vbe‘ made 75 thereon, containing from 7-0: to 90% by volume 2,408,381 of ethyl alcohol f0r_from 5 to .60 seconds at a temperature or. 65 to 110‘? F., removing excess liquid from the staple ?bers, immersing the staple ?bers Water at a temperature of about e-v ‘- the staple ?bers and drying the staple ?bers, whereby voluminous, permanently crimped staple , ?bers .are produced. _'7.*Process for the production of voluminou 150 to 160° FylfOI' from 1 to 5 seconds, removing ' ' permanently, crimped arti?cial staple ?bers, vwhich comprises immersing relaxed, unstretched the water from the staple ?bers and drying the and unassociated dry-spun staple ?bers, having staple ?bers, whereby voluminous, permanently a basis of cellulose acetate and prepared from crimped staple'?bérs are produced. 6. Process forth'e production of voluminous, ?laments spunriwithout any tension being exerted lwhich comprises immersing relaxed, unstretched and unassociated dry-spun staple ?bers, having ' of 90° F., removing excess liquid from the staple permanently T‘crimped arti?cial staple ?bers; 10 thereon, containing 80% by volume of. ethyl alcohol ‘for about 30 seconds at a temperature ' a basis of cellulose acetate and prepared from ?laments spun without any tension being exerted thereon, containing,80% by volumeof ethyl ‘al ?bers, immersing the staple ?bers in water at a temperature of about 150 to 160° F. for about 5 seconds, removing the water from the staple cohol from 5fft6f 60 seconds ‘at a temperature of 65 to 110151‘v iizfremoving excess liquid from ?bers and drying the staple ?bers, whereby voluminous, permanently crimped staple ?bers the staple ?be'rs_,_; "mmersing the staple ?bers in are produced. water at a temperature of about 150-to 160°, F’. for about 5 seconds, removing the water from 20 ' a FREDERICK G. DODGE.