CA2424291A1 - Composite yarns and moisture management fabrics made therefrom - Google Patents

Abstract

A composite textile yarn and a moisture management fabric made therefrom, the yarn comprising hydrophilic fibers embedded at the yarn center within a matrix of hydrophobic fibers such that the hydrophobic fibers are concentrated at the periphery of the yarn, a transition area between the center hydrophilic fibers and the peripheral hydrophobic yarns in which both fiber types are present.

Description

AF~i~ i'°fP~F3~F~9~t QUO i~ This invention relates in general to a class of composite textile yarns for use in forming moisture management structures. tviore specifically, it relates to improved moisture management textile composite yarns comprising hydrophilic fibers embedded within a matrix of one or' more hydrophobic fibers, in which there is a gradual transition between f fiber types. The transition begins at the center of the composite yarn where hydrophilic fiber s are concentrated and progresses to the outermost lay;~r where hydrophobic fibers predominate.
Further, this invention relaxes to unpr owed moisture ~~anagement fabrics and garments produced by the use of the aforementioned composite textile yarns alone or in combination with other yarns.
~002~ in recent years, "structured fabric'" {also referred t~ as "engineered fabrics"') have become very popular in many application areas of cornmercia!
interest. /~ particularly important class of such structured fabrics is referred to commonly as "moisture management" fabrics. In general, fabrics of this type utilize two or more fiber types in layered structures that are formed so that the two sides of the fabrics are distinctly different in character. In particular, each side of the fabric exhibits different perforr~anoe characteristics and properties with regard to water and water vapor. The innermost layer, or the fabric side that comes into contact with the body of the wearer, is comprised substantially of hydrophobic fibers, while the outer layer is made up substantially of hydrophilic fibers.
t ~t~g3j Lightweight, two-sided ~rabrlcs for use in moisture management applications also are produced by the use of "plate°' knitting techniques. 6n plate knitting such fabrics, both hydrophobic and hydrophilic yarns are fed to a single set o~' knitting needles so that two dispara~~e yarns pass througl~~ each single needle of the set. 'kith careful control of the feed and positioning of the hydrop''~~obic and hydrophilic yams, the resulting 6~plated" fabric ~n~iil show only hydrophobic yarns on one side and hydrophilic yarns one the opposite side.
~g04j The principal end use application areas for moisture management fabrics are, without limitation, in aotive sportswear garments, ~orl~ clothing, intimate appa9el, exercise garments, and footwear. Bn uses in garments that contact the body of a physically active uvearer, tf~e rr~oisture management ~sabrics, act to prevent, or minimize, the collection of perspiration as a liquid against the body and in the fabric Bayer next to the body of the wearer. T he perspiration, in liquid or vapor form, Beaver the skin surface and diffuses, or wicks, through the hydrophobic fibers and is absorbed by the hydrophilic fibers in the outer fabric layer. The perspiration that passes from the skin surface through the hydrophobic fibers is absorbed by tine ouver Bayer of hydrophilic fibers and, then, evaporated into the ambient atmosphere away from the body. The transport of moisture from the body of the wearer to the atmosphere in this manner incr eases the comfort leveB of the garment to the wearer by preventing or minimizing tB~e formation of wet areas at the skin suraace or in the fabr is layer nearest the skin.
~urtt~er, by avoiding the collection of liquid perspiration at the body surface and in tire fakaric next to the body, the insulating vralue of the garment is improved so tflat it feels warmer at Bov~a ter npera~iures and cooler, dare to an evaporative cooling effect, at higher ambient temper stores to the wearer.
~D05j The driving force; which causes the t~wansport of mater from perspiration as liquid and vapor by the process described Br~~ the foregoing, is sometimes referred to as a "push-pull'° effect. ~ hat is to say" perspiration is repealed by the Bayer of

2 hydrophobic fibers and ''pushed", or ''wicked"$ into the layer ofi hydr°ophiiic f Ebers, where it is absorbed or "pulled" away. ~4ctual(y, the movement ofi moisture from the skin to the outer atmosphere is driven by the large difference in h~rrnidity between the inner layer against the skin of the ~~Fear er and the ar~bier~t atmosphere. Further, the movement is facilitated and direcaed away fr~or~ the body by the structured arrangement of l 3ydrophobic and hydrophilic fiibers.
~(~06] ~Ithough moisture rr~anagerr~er~t fabrics can be produced on weaving loors~s, most commercially interesting fabrics or' this type are knits that are produced ore warp or circular knitting equipment. ~f~e hydrophobic fibers of choice generally are melt-spun from polyester, nylon, or polypropylene polymers.
These fibers may be in the form of staple yarns, flat continuous muitifilaments, or texturi~ed continuous multifi(aments. For the hydrophilic side of the fabrics, the most popular fibers in use are based on modified nylon polymers. In general, such nylon polymers are provided v~ith a (~y~~rophi9ic ne~ture by causing chemical modifications to the nylon polymer ch~:in dur ing the po.(ymer~ization step.
this is accomplished by the chemical addition of hydrophilic sites as segments ~rithin the nylon polymer chain or by the chemical attachment of hydrophilic sites as branches to fibs nylon polymer chain. ~s(terr~atively, n~~lon fibers rrray be made topically hydrophilic by sub~ectirag the fibera to chemic>al reactions that serve to attach hydrophilic sites to the nylon polymer at the surface, or very ne<~r to the surface, of the fibers. ether less popular hydrophilic fibers are produced firom modified polyvinyialcohoi, acrylic, and cellulose acetate polymers. l iere again, the hydrophilic fibers may be in the form of staple yarns, filet continuous mu(tifi(ar~ents, or texturi~ed continuous rrlultifiiament s. 6r~ some cases, cotton and rr~odified cotton yarns also are used as vhe hydrophilic component.
~OC~7~ even though the structured fabrics of the prior art have been well received in the marketplace, they have a number of disadvantages, which limit their utility in certain applications. Cane of the more iu~portant problem areas involves the need to use a r ninimum ofi two yarr7s ~nrith knitting or F~aeavirZg equipment that is capable of producing fabrics with two distinct tides. ~'~te use of such eguipment results in products that are rather high in cost. ~xampfes of other problem areas are summarized in the paragraphs that follov~.
g0~~ !n most cases, there are significant differences in dyeability and dye fastness properties between tfi~e hydrophilic and hydrop~i~or~ic fibers that are used i,n a particular moisture management structure. ~ue to such difference s, it can be difficult and, at times, even impossible to produce a dyed fabric of uniform color. ~rten, two or more dye types, as we;! as multiple dyeing c'rcles, mast be employed in order to obtain acceptable resc~lts. This can increase substantially the dyeing and finishing costs for moisture management fabrics.
~g09~ As aforementioned, moisture rnanagc~ment fabric based on the prior art are formed so that the fabric side, vrihich is in contact v~rith the skin surface of tie wearer, is hydrophobic, while the outer fabric surFacr: contains the hydrophilic fibers. This creates a serious problem in certain important applications for moisture management fabrics. !t is a problem particularly in the area of active sportswear and promotional items where tire outer garment surfaces often are screen or transfer printed with names, logos, and other bold design features.
serious problems can occur because the preferred hydrophilic fibers based on modified nylon polymers perform very poe'rly as substrates for the commonly used screen and transfer printing dyes and inks. As a result, it is either impossible or costly to pr int a broad range of br fight colorful designs onto i~noisture management fabrics based on the prior art t~:chnology. ~Sandv~rich-plate knitting techniques, in which a hydrophilic yarn is sandwiched bet~nreen two hydrophobic yarns and red io a single set of knitting needles, can ameliorate printing problems, t~ a cer~~ain extent, day fc~rrr~ing a sandwich-plated outer fabric surface or by forming both fabric sides by such knitting techniques. Although this approach does position hydrophobic fibers in the outer fabric surface so that it is receptive to screen and transfer prints, it is a difficult technique in practice, since three yarns must be fed to each single needle in a fixed order. Further, the disparate yarns easily can slip out of register in production arid usage. This lack of precise register of the sand~.~iched yarn structure leads to blurred prints.
[0G10] Mechanical properties; including abrasion resistance, normally are lower for the preferred hydrophilic fibers based on modified nylon polymers than a they are for the most commonly used hydrophobic fibers, such as polyester and oofypropyfene. This can complicate knitting and limit application areas in which the structures can be used successfully.
[t1011] The tactile properties of the commonly used hydrophobic and hydrophilic fibers often are quite different. ~It1-~ough it is not a problem with the less used sandwich-plated knit fabrics, the two sides of the more commonly used moisture management fabrics exhibit a very different: "hand°' or~ "feel", depending on ti:e fabric surface that is touched. This can be a serious disadvantage in certain applications, such as intimate apparel.
[0g12] In the process of c~ctting and sewing moisture management fabrics with two sides having very different properties into garments, footwear, and ovher er~d use items, great care must be taken to maintain proper orientation and placement of tree fabric surfaces. ~I~ould the sides be a°eversed in making the finished item, the resulting product cannot manage moisture effecti~aely.
[0g13] ~.~. patent 4,~21,~89 to Ho~rurna ~kada discio~ses a textile fabric.
utilizing cored yarns, which fabr is is said to be breathable such that the outer fibers which contact the skin of the wearer can be kept substantially dry at all times e~ren though water vapor from perspiration is wicked. The core yarns cornprise a thread wadding composed by a bindle of inner hydrophilic fibers, and a thread sheath cornposed of a plurality of outer hydrophobic fibers aarranged exfieriorly of the thread wadding so as to s~bstantialiy completely enclose the inner fibers.

~~10 ~j The principal objective of this invention is to provide a stb~uctured composite yarn with both hydwophilic and '~~~~drophobic properties that can be used atone or in comblnatior" with otl~~er hydrophobia; yarns to produce:
highly efficient moisture management fabrics. l~ fort her objecti,~e is to employ a composite yarn comprising a hydrophilic fiber imbedded ~nrithin a matrix of a hydrophobic fiber, either alone or iii combination ~rith ore or more hydrophobic yarns, to form l~nit and v~rover~ moisture management fab~~ics. The resulting moisture management fabrics, whsle managing moisture as well as, or better than, prior art fabrics, substantially oa~ercor~e the aforefr~~e:~tioned deficiencies that limit the utility of moisture management yarns and fabrics, vrhich are based on the prior art.
~00'i 5j The present invention satisfies the foregoing objectives by employing air entanglement texturing eguipment to form a composite yarn by inserting a multifilament hydrophilic yar n into an air jet entanglement or texturing device along with a muitifiiament hydrophobic yarn. i3y carefully controlling feed rates, air pressures, and the relative feed tensions of fl se two disparate yarns entering the air jet, the composite yarn exiting the air entanglement machine has hydrophilic fibers concentrated substantially at its core, wf~ile the hydrophobic fibers are concentrated substantially at its periphery. There is no sharp demarcation area separating the hydr ophobic surface fibers from the hydrophilic core fibers in the resulting composite yarn. Rather, the outer surface of the composite yarn is made up substantiaify of hydrophobic fibers, while hydrophilic fibers are concentrated at the center of the composite. A transition layer, comprising a mixture of hydrophilic and hydrophobic fibers, Ties between the center and the outer surface of the composite yarn.

~gg16~ 2t has been fond that the presence o~ intir~aafioly cornc~~inglec~
hydrophobic and hydrophilic filar~onts within the cross-section of the co~~posite yarn cross section leads to a more rapid transference of moisture thorough the peripheral hydrophobic fibers and into the centrally concer~tra~:ed hydrophilic ficaers as corr~~ared to con~entiona! sheathcc~~re composite yarns prepared, for eacample, according to the teachings of the abo~ementioned ~kada patent. lr~ like s nannes~, the area of intimate cor~rr~ingling of hs~drophilic and hydrophobic fibers accelerates the transfer of r~~oistc~re in the °v~~por form i~ror~°~ the inner hydrophilic fibers through the h~°drophobic fibers arid ir~tc~ the atmosphere.
~0017~ The area within the yarn cross-section ~~herei,~ hydrophilic and hydrophobia fibers commingle is critica!!~F important to f:he superior performance in moisture management fabr ics of the corr~posite yarns of ~:he in~~entior~.
This can be understood by a comparison ~~vith tre sheathe'core moisture co~~nposite yarns of the prior art in wvhich the s~ydrophilic core yarn is tightly ~rrap~ped by hydrophobia fibers. !n such yarnsF the in'cerface betwe~:n i-~ydrophobic fibers and hydrophilic fibers is propor~ionai to the scgu;~re of the r adios of the hy~lrophilia bundle of vibers at the sore. For the c~orr~posite yarnv of the inr~entio~, commingling of the individual ~~ilaer~ts of hydropho~=ic and hydrophilic fibers results in a substantially larger intermace area.. This roar ease occurs because fibs interface ~naithin the comrr~inglir~g area oa tl~~e c>or~posite yarn is proportions! to the square of the radii of the much finer indi~id~~a! iiiar~eni:.s oi° the hydrophobia and hydrophilic ~°arns. ~n increase in the area of the intertaae bEa~eera hydrophobia and hydrophilic oorr~ponents does not increase the tots! amount of rrcoist,.~re that can be taken ul,:b by the composite ya.rr~. n increase in interface, hea~ve~er, increases the kinetics of absorption so that moisture transfer beaorr~es more rapid and effective in the moisture rr~anager~~~nt fabric.
~Ci01 ~~ V'~hen in a garment against the skin surface of a °~earer, this unique composite yarn structure leads to an efficient and rapid Making efFect of perspiration moisture from tl~e oyster hydrophobia fibers in contact v~sith ~:he skin surface to the inner hydrophilic fibers of the °;~arn. n tt~o gar~rr~ont surface array frorr~ the body of the wearer, the moisture e'~aporates ivror~ the inner hydrophilic fibers and passes through the outer fqydr~ophc~bic fibers to the atmosphere.
[g0~g~ 6n a t~o~sided moisture r~anage;~er~t fabric, the composite yards of the invention rep9aces the hydr opl°~ilic yarE r that ~>ould bra posii:ioned in the outer fabric surface of a moisture ~~°~~anagerr~ent fabric based on prior ai°t technology.
the resulting two-sided fabric has one side made up of hydrophobic yarn, ~:~hi~e the opposite side contains a composite yarn of the invention alone, or in combination ~rith, a hydrophobic yarn. f~°~ a ~~noisture r~~anagernent garment, or other end use article, in contact ~.~ith ~~he body of $~ wearer, n~oist~,sr a from perspiration passes from the shin surface through the hydrophobic fibers> of the inner fabric layer and, then, through the per~phera;! hydrophobic rr~atri~ and into the inner hydrophilic fibers of the cor~nposite yarn of the outer layer.
Finally, the moisture evaporates from the hydrophilic iibcrs, passes through the hydrcyphobic peripheral fibers of the composite yarn, and into the atrncaspher e.
[00~0~ ~y using the uniguely structured com6~osite hydrophilicfhydrophobic yarns of the invention in the production of ~~~oisture management fabrics and gar rr~ents, the problems associated °~vith products based on prior art tfechnology that are described in the foregoing ar a a'~oided. the reasons for these r°na,r fed improvec~r~ents are sumrnari~ed briefing in the follo~~ing p~cragraphs.
jgg21~ ~fith clear, du!!, or roeutrai colored f~ydrophilic fibers embedded vi~ithin matrices of hydrophobic 'fibers in co~~nposite earns of this invention, it is possible to dye only the hydrophobic fibers ar"d leave the hydro~~l~ilic fibers undyecl, since they ~ilf be substantially concealed by the cuter hydrophobi > fibers. ~Iso, if a fiber such as polyester is used as the hydrophobic coeH~ponent, it ~~ri!! be at the yarn and fabric surface where it vrilaccep;: readily sc:~meen and transfer prints.
For the sar'ne reason, fabric tactile prope~°~ie~~ evil! be d~:pendent pri~~arily on the hydrophobic fiber at the surface of the composite yarn. Further, r~echa.nical properties of fabrics, such as abrasion resisiarace, ~vi(( be contro!(ed prir~ari(y by the hydrophobic corr~por~er~t of the composite yarn structure.
jfl~22~ ~r~ ~dditiC~(~a! ad~ar~tage for this ir~~er~tior2 over p~~:rvior art techr~o(og~e is that the unique character of the composite ~~arr~s based thereon permits the production of moisture management fabrics vrorn a sir~(~(e composite yarn.
Thir feature of the ir~~er~fior~ rr~akes possible the use of simpl!'c~r and louver cost knitting equipr~er:f arid procedures ohar~ those r~~c~uirec~ ~,er~ using two or more disparate yam's as required by t~~e technology disc>losed in the prior art.
~ependir~g on the kr~l6fing technique used, th~~ two sides of the resulting rr~oisiure r~r~anagement fabrics may be identical. ~ hi~> is an irr~por~~ant advantage for the in~eration, since, with fabrics haying i:~terchar~geable sides, vv«rkers cannot make the rr~istake of using the v~~rong fabric side ire the cuttir~~g and sewing operations required in producing the er~d us~~ products. ~ing(e-yarn fabrics that are produced by using composite yarns of this ir~~°er~tion have 'Lhe sarr~e hydrophobic a~bers exposed ors both sides. !r; a garr~eni, hydrophobic fibers are in ir~tirr~ate contact with the body of the wearer. ~ erspirati~ar~ icy v~icked rapidly into the interstices of the composite yam v~a~ere it is absorbed bar the hydrophilic fibers imbedded within the hydrophobic fiber matrix. The t~oiature, then, is transmitted through the hydrophilic fibers to fhe outer ~°abric surface, °here it evaporates from the hydrophilic fibers as~~d the ~!apor passes through fhe outer hydr~)phobic fibers to the atmosphere. This r~oisfure transport oc~;urs ~rith equal evticiency irrespective of which fabric surface contacts the e~°earer and uvhich is exposed to the atmosphere, as the moisture rrao~es f~~om the high h~.arnidity at the skin surface to the louver humidity of the atmosphere.
jg023~ The composite yarns of the invention are particularly ~asefu! in the production of tvvo-sided moisture rnanager~~ent fabric:r sis~ilar in stru~aure to fabrics based on prior art technology. !n suc(~ fabrics uf:i(i~ir~g composite yarns of the in~enfion, ho~re~er, the cos~posite yarn replaces ~:he hydrophilic yarn that v~rou(d be used, according to the prior art, in the outer layer c~f the fabr is that is away from the body of the wearer in a finished garment. C~epending on the effect desired in the structured moisture rr~ar'agement fabric and the end use garr~er~t, the composite yarns of the invention :gay be utilized, alone or in combination with hydrophobic yarns, for both sides of the two-sided fabric. Then composif;e yarns of the invention are used in producing two sided fabrics, hydrophobic fibers are at the surface of both the inner layer and outer layer of the finished fabrice.
~s a result, transfer or screen printing can be done or either or both fabric sides so tl-iat prints in complex designs and bright, sharply-dsfirEed color patterns can appear on either or both surfaces of the finisi~ed garment without the corr~p(ications associated wivh screen and t;-ansfer printing onto s~~rfaces made up primarily of hydrophilic fibers, such as the modified ~aylon based Fibers.
j00~~.] These and other ob]actives, featur~a, and a,dvar~tages of the present invention will become appar ant upon r ending the following detailed description and claims and studying the drawings.
I~F ~~~IF ~~IIV F' '~ Fl~ ~~,'!~'(~
[C~Q~S] FIG. ~ presents an enlarged ~.:iew of a typical hydrophobiclhydrophilic fiber d(str(bution within the composite yarn of the present invention by a sketch of a cross-section taken at a rigl~'t angle to the for ~g axis of the yarn structure.
FIG. ~ presents an enlarged view of a typical distrib~stion of hydrophobic and hydrophilic fibers within the ccfrnposite yarn of the present invention by a sketch of a side view along the long axis c~f tae yarn stricture.
F(G. ~ illustrates an enlarged view o~r the composite yarn of this in~fention plied with a yarn of hydrophob(c fi(a3 vents.
FIG. 4 illustrates an enlarged view of the composite yarn of this invention plied with two hydrophobic yarns.
t~

~1~. 5 illustrates an enlarged p9an view o~F a plain l~r~it ;moisture management fabric formed by ~tilizir~g only a singly: hydrophobiclhydrophific composite yarn based on this inveni:ior~ to produce a ~r~r~sctu5e in which the two sides are ss~bsta~~tially identical.
!=lC~. 6 is a representation of typical path~rays for° hydrophobic and hydrophilic fibers as they ~,re processed =gin are air-jet te;cturinel machine vo produce the composite yarns of the present ia~vef-~tior~.
~~~1~~~ ~~il~~~i~«~' T~I~~~~~'~~~1 ~g02Cj the present invernior~ provides ;~ cor~posiie yarn, cor~prisir°rg a combination of both hydrophobic and hydr ophilic fibers: in which the hydrophilic fibers are concentrated in the interior of the yarn and tl~e hydrophcmbic fibers are concentrated peripherally, while the:a is a corr~rnir~glir~g of both filarner~~t types ~ithir~ are ir~terrr~ediate area between the yarr ~ center arr~J its periphery. also, the invention provides highly effective r~°oist~are ~~anagerr~ent fabrics made by using only a composite yarn of the irwer3tion or by using a hydrophobic> yarn for the fabric side 'shat will contact the body of l~he wearer arid the corr~posite yarn of the irsventior~ for the fabric side away from the bod;~ of tire wearer. further, the invention provides highly effective rr°3oisture r~anagem~.=rat i'abrics rr~ade by using only a cora~posite yarn of the irwentiors cr by using a i~ydrophobic yarn for the fabric side that will contact 'she body of tr,e ~n~earer and the corr~posi'te yar~~ of the irwer~tior~ plied ~°ith one or more hydrophobic, yarns for the fabric side away front the body of the wearer. ~ir~ilarly, a caorrtposi~~e yarn of the irwentior~ may be plied with one or more hydrophobic yarns a~~~d used grit!-soot other yarns ire producing moisture rr~ar~agement fabrics.
~0027j °l'he arrr~~ular area ~~ithin tee~ composite yarn, c~°oss-section in ~vhicl~
hydrophilic aid hydrophobic fibers. cor~mdngge that lies i~et~veen the inner hydrophilic fiber concentratiorg and the peripheral cor~c~eritration of hydraphobic fibers is an important and unipue feature of u:he compo:rite yarns of the ir~verstior~.
in a conventional sheath core composite there is a clear transition between hydrophobic and hydrophilic fibers within the yarn cross-section. ~~s a result, the interface through which moisture must penetrate: in crossing from the hydrophobic fibers to the hydrophilic fibers is very restricted. E3y providing an area of commingling of hydrophobic and hydrophilic fibers within the cross-section of the composite, the composite yarns of the invention gr~eatiy increase the area per unit length of the interface through ~ruhich the moisture must penetrate to be absorbed by the hydrophilic fibers. This increase in interface area per unit length acts on the l~ir~etics of r~oistur~: trar~sfer to incr~,ase the transfer rate arid efficiency.
[C~02g] The hydrophilic fiber corr~pone!~t of the composite yarn of the invention may be in the form of a continuous fat muitifilar~er~t yarn, a continuous tc;xturized multifilament yarn, or a staple fiber yarn. The hydrophobic fiber also may be in the form of a flat multifiiament yarn, a. texturized mui~:ifiBar~ent yarn, or a staple fiber yarn. if the hydrophobic yarn is in the form of a ,staple fiber yarn, however, great care must be used in forming the composite to a~joid breakup of the staple fiber yarn. Further, for applications in which hi~l~ abrasion resistance is rer~uired, the preferred form for the hydropi~obic corm:>onerif: is a continuous flat or texturized multifilament yarn.
[0029 FiC~. 1 represents are enlarged vieva of a typical crass sectior~~il profile, taken at a right angle to the longitudinal axis, of the composite yarn generally designated 3 of the invention. The hydropi'iilic filamerns 1 are shown as shaded opera circles, while the hydrophobic filaments 2 are shown as open circles without shading. ~s can be seen in FIV. 1, the hydrophilic filaments are concentrated near the center of the cross-section, and the llydrop°~obic filaments are concentrated to the peripheral of the composite yarn, l-iydrophilic and hydrophobic filaments can be seen clearly ~dommingled at an inter mediate area between the composite yarn center and periphery dvith no clear interFace.
[0030] FiG. ~ represents an enlarged side v~lew along ~:b~e 9ongitudinal axis of the composite yarn 3 of the invention and shows hydrophilic filaments 1 concentrated near the yarn core surrounded by a matrix of hydrophobic filaments 2.
~3irr~ifarly to Fig. 1, FiG. 2 illustrates a commingling of hydrophilic and hydrophobic fibers in an intermediate area between the composite yarn's center and its outer surface. Further, the sketch of Fig. 2 illusi:rates a gradual migration along the longitudinal axis of the composite yarn 3 of hydrophobic fibers 2 from the yarn periphery to the transition gone of principC,! commingling along and, ever, into the centre! area where hydrophilic fibers 1 are concentrwted. Similarly, hydrophilic fibers 1 migrate between the central gone of the composite yarn v and the periphery ~~~ahere hydrcaphobic bribers ~ are conc~:a~trated. This physical interchange of fiber positions within the yarn has the effect of accelerating the transport of moisture into the hydrophilic fibers °! eon~:~.ntrated at the composite yarn center.
[0031] Depending on end use applications, the perceraage of hydrophilic fibers needed for optimum mechanical and comfort performance in the mristure management fabric may ~,~a~~°y from a Eow of ~ to 10 percent to a high of ~0 to ~5 percent by weight. Further , from aineconor~~ic standpe~int, it is desirable to avoid the use of more hydrophilic fibers in the fabric structure Than the amount required for optimum moisture management performance, as the hydrophilic fibers cost substantiaiiy more than the hydrophobic fiber s.

[003] T'he hydrophilic fiber conte,~t in a moisture rr~anagement fabric. of the invention may be varied by adjusting the r atio of hydrophobic to hydrophilic fibers used in the preparation c~f the co~~posite yarn of the invention. in practice, however, it frequently is more ec~onomic~~! to produce a !invited number of standard composite yarns of the invention with fixed hydrophilic fiber contents and, then, to adjust the hydrophilic yarn content i~a~~ the finished rvtoisture management fabric by plying composite yarns wiih one or more hydrophobic yarns. Fig. 3 shows an enlarged side view of the composite yarn 3 of the invention with both hydrophilic 1 and hydropl-~obic 2 fibeE~s plied with a continuous rr~ultifilamer~t hydrophobic yarn 4 comprising a sentially ~ 00 percent hydrophobic filaments. !n like manner, Fig. 4 illustrates a magnified side ~~iew of a composite yarn 3 of the in~°ention plied with two continuous multifilamenv hydrophobic yarns

4 and 5 each comprising essentially 100 pert<ent hydraphobic filaments. The two hydrophobic yarns ~ and 5 may be identical or difi'erent; depending on the effect desired in the plied composite yarn and in the moisture management fabric. For example, one hydrophobic yarn cauld be based on polyester and the other polypropylene. Further, in order to obtain ,:~ fabric with a soft hard ~i.e., a soft feel) and a high resistance to abrasion, the corr~posite ,mrn of the invention could be plied with one polyester aaarn comprising monofilaments of normal deniers in the range of 1.b to 3, while the other would comprise micro manofilaments with deniers well below ~ .
X0033] The hydrophilic fiber content in a moi;~ture management fabric also can be adjusted by knitting alternate courses of the composite yarn 3 of the invention along with courses of a hydrophobia yarn.
~0034~ The sketch of F1G. ~ shows an enlF~rged plan view representation of a plain knit fabric produced fram a single composite yarn 3 of the in vention containing both hydrophilic 'i and hydropt'obic ~ fibers. ~ue to the unique structure and properties of the composite ararn of the invention, such a simple fabric structure is effective in absorbing perspiration frorr~ the high humidity atmosphere at the skin surface of a wearer and, then, evaporating the absorbed rr~oisture from tree inner hydrophilic fibers through the irt~ydrop~habio matrix, fiber at the opposite fabric side inta the lower humidity at ambient conditions. In rr~arked contrast to fabr ics based on the print art, the fabric of the invention will function to transport moisture from the skin of a wearer to the atmosphere equally well, t~

irrespeotive of which fabric side is in oontact with the body. further, since the outer surfaoes of both fabri=: sides are made up substantially of hydrophobic fabrio, garments based on the single oomposite yarn fal:~ric ~meadily accept screen and transfer printed designs on either or both fabric sides.
~6035~ The hydrophobio fibers of most interest for use ~~in the composite yar ns of the invention have loqr~ moisture regain vales. The preferred hydrophobic fibers for a majority of current er~d uses for moisture' management fabrics and gs~rmenvs are derived from; either polyester or n~rlon polymers. i~ther hydrophobic fibers that can be used in corr~posite yarns of vhe invention include fibers ba sed on:
polypropylene, polyvinylchloride, and polyacrylonitrile polymers. ~Ilthough hydrophobic fibers based ort polyester and, to a less~;r extent, nylon polymers are preferred for most moisture may ~ages~ent fabrics and garments of ourrent oommeroial interest, the hydrophobic fiber actually chosen for use in a particular application must be selected or= the i~asis of ~,conomics and the needs of l:he end use application.
[6036 The hydrophilic fibers for use .r~ i:he ccmposite yarns ofi the invention must have high moistcare regain values, The preferred hydrophilic fibers pare baased on modified 6- or 66-nylon polymers. ~' particu;,arly useful modiried 6-nylon fiber is supplied under the trade nay ne "I-iydr ofi~". Tl~e ~Ilied~ignal Cso. Haas the original developer and supplier of this products but it, now, is produced and supplied by Universal fiber systems, ~~~. ether useful products based cJn a modified nylon product that can be used as the hydr ophilic component for tt'~e composite earns of the invention include fiber s sold under the trade names of '"~~uup" and "'~lygra".
Toray pylon, Ltd. of Japan produces ''~uup" in oontin~ar~~cs muitifilament for~'d by melt extruding a modified 6-r~ylor~. "~lyg~-a" is also produced and supplied frorr~
Japan. It is a structured sheafi~core bicompo=~ent fiber ira which the outer surface of the individual continuous filaments is comprised of a hydrophobic 6-nylon, while the core is comprised of a hydrophilic modified 6-nylon. This 'fiber is produced and supplied by l~nitiica F=ibers, std. ether hydrophilic fibers oi° lesser l interest include: cotton, cellulose acetate staple yarns 'end fil~rnents, rayon, linen, modified acrylicss and rrrodified polyvinylalcohols.
~003~j As aforerrrentioned, the composite yarns of the invention cor~~prise IT~ydrophific fibers embedded ~aithir~ a rr~atr ix of texturi~ed hydrophobic fibers.
~)epending on the effect desired i~~r the finished pro~;~u=.~t, f:he h,rdrophilic fiber might be in the forrr~ of fiat continuaus filarrrents, textur~.d continuous filaments, or staple yarn. the hydrophobic rrsatrix component also rraay be in the forrr~ of a flit or textured continuous filament farrno but a staple y~Bn form is only rarely appropriate, as air jets in the air entanglement eguipment tend to disrupt a staple fiber yarn.
X0038] ~Ithough other approact~e:~ are yossible, the preferred pro~.ess qor producing composite yarns of the in~~ention is to pass tree twci fiber types together tllrough an air jet of the type commonly used in air jet texturing eguiprr~~;nt. '~ he feed rates must be carefully controlled in order to easure a concentration of hydrophilic fibers toward the cena:er and the hydrophobia fibers tor~rard tire periphery of the resulting composive drag n, this objective is accomplished by feeding the hydrophilic fibers under tension, while tl~e hydrophobic fibers are overfed. fir jet yarn texturing rrrachines of use in pro~ucinc~ composite yarns of the invention are supplied by a number of textile eguig~ment fabricators.
r~ong ti~ese are IG~~' in prance, ~taehle in ~errr~any, and ~:!~enegatto in Italy.
~'l~ 0 illustrates typical hydrophobic and hydrophilic fiber pathways in an air-jet texturing rrrachine as supplied, for example, by the aforemeni:ioned fabricators.
[0030] In dig. 8, a positive dr ive feeds the hydrophilic r~uftifilament continuous yarn ~ at a fixed rate and controlled tension through es-ary guides 8 into the air-jet cavity 0 of are air-jet texturing device. ~,n overfeed assembly pulls the hydrophobic rrrultifilarrrent yarn 2 over the errd of the sc.~pply ~,ac~age and feeds it s;t a higher feed rate than they used for the l~ydropl~ilic yar ne ,,,hrough entry guides 8 into the air jet cavity 9. he relative rates by weight at v~hich the hydrophilic and hydrophobic yarns are fed mush: be adjusted so tl~:at the finished composite yarn will contain a minimum of 8 percent by °aveight but not more than 7~ percent by weight of hydrophilic fibers. To are extent, feed adjustmer"ts may be made by o'rer-feeding the hydrophobic by up to ~0 percent. Further, :adjustments can be made by selecting different hydrophilic and hydrophobic yarn deniers (l.c., sizes) tc produce the composite yarns. ~~r~ exiting the air j~-~t cavity 9 t:he composite 'yarn passes through a heat setting assembly '10. Finally, a v~~inding assembly ~ 1 takes up the composite yarn onto a bobbin 1 ~.
~0040j As the hydrophilic 1 and hydrophobic 2 yarns pass through the violent, I-~igh-velocity air stream maintained in the air jet cavity 0, the hydrophilic filaments substantially main'cain their integrity, due ~ia t:he controlled tension maintained by the feed control assembly 0. ~'he individual monofiiaments of the overfed hydrophobic yarn ~ are blown abo~~t violently by the air stream ire thE: air jet cavity. As a result, hydrophilic filaments under tension are caused to cor~cer~trate at and near the center of the composite yar n that exits the jet cavity, while the hydrophobic fifamer~ts are con~.;entrated peripherally.
~004'ij ~Ihen a thermoplastic fiber is texturized in an air jet or other texturing equipment, the fiber is heat set as it exits 'che texturing gone e~f the machine. Fig.
0 shows a heat setting cavity ~0 just below the air jet cavity 9. Hydrophilic fibers produced from modified nylon poiyr~ers, however, ma_~~ mel~~ if exposed to heat setting temperatures commonly used for polyester ba.;~ed, as well as for sore other, hydrophobic fibers. ~°onsequently. it is necessary to minimize the temperatures and dwell times used t:o heat set the hydrcphobic fibers when producing the composite yarns of the invention. Fo~.~ certain combinations of hydrophobic and hydrophilic fibers, it is n;~t possible to properly heat set the 1-~ydrophobic componen'~ of tl~ae corr~posite yarn without: dams~ging ~:he hydrophilic fiber. In such cases, it is possible to produce a good quality composite yarn by, first, texturing and heat setting the hydrophobic component: and, then, running fhe pretexturized hydrophobic and the h°ydrophiiic fibers through the;
air jet i7 f~~f~r~~g ~q~ipr~er~f °v~ifhc~f ~ppi~irEf~p~r~f~r~ fc~ thc~ heat s~ffing~ ~cn~.
~~~rfher, d~p~r~di~g cry fhe p~r~crr~~r oc~ char~cfer2sfics ~~~~d~:d i~ fh~
ccrnp~sife y~rr~, If c~r~ b~ pr~fer~dle fc piss ~c~fi°~ fhe hydrc~phiiis:~ ~~d h~drcphcdic Harris fhrc~~gh fhe sir ref f~~f~ri~g ~chir~e i~ifhct~f he~f s~ffinc~. this is p~rfic~i~ri~ fh~
c~s~, if a v~r~ lighf~eighf ccr~pcsif~ ~ ~r~ is desired.

Claims (13)

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:

1. A composite textile yarn, comprising both hydrophilic and hydrophobic fibers with the hydrophilic fibers embedded substantially at the yarn center within a matrix of the hydrophobic fibers with the hydrophobic fibers concentrated at the periphery of the yarn, there being a transition area between the center hydrophilic fibers and the peripheral hydrophobic fibers in which both fiber types are present.

2. A composite textile yarn, comprising at least 8 percent but not more than 75 percent by weight of hydrophilic fibers embedded within a matrix of hydrophobic fibers with the hydrophilic fibers positioned substantially at the yarn center and the hydrophobic fibers positioned predominantly at the periphery, there being a transition area between the center hydrophilic fibers and the peripheral hydrophobic fibers in which both fiber types are present.

3. A composite textile yarn according to claim 1 or 2, wherein the hydrophobic fibers comprise flat or textured continuous filament yarn of polyester fibers and the hydrophilic fibers comprise flat or textured continuous filaments of a modified 6-nylon or a spun staple yarn of a modified 6-nylon.

4. A composite textile yarn according to claim 1 or 2, wherein the hydrophobic fibers comprise flat or textured continuous filament yarn of polyester fibers and the hydrophilic fibers comprise flat or textured continuous filament or spun staple yarn of a modified 66-nylon.

5. A plied textile yarn, comprising the composite textile yarn according to claim 1, and further comprising a hydrophobic yarn of essentially 100 percent hydrophobic fibers plied with the composite yarn.

6. A plied textile yarn, comprising the composite textile yarn according to claim 2 and further comprising a hydrophobic yarn of essentially 100 percent hydrophobic fibers plied with the composite yarn.

7. A composite yarn according to the claim 1 or 2, produced by feeding a flat or textured continuous filament hydrophilic; yarn under tension at a predetermined rate into an air jet texturing device along pith a flat or textured continuous filament hydrophobic yarn fed at a rate of at least 10 percent but not more than 50 percent greater than said predetermined rate.

8. A moisture management fabric made from the composite yarn according to claim 1.

9. A moisture management fabric made from the composite yarn according to claim 2.

10. A moisture management fabric made from the composite yarn according to claim 3.

11. A two-faced moisture management fabric for wearing apparel, comprising at least one hydrophobic yarn essentially 100 percent hydrophobic fibers, and a composite yarn according to claim 1, the hydrophobic yarn being concentrated in the body contacting face of the fabric, and the composite yarn being concentrated in an outer face of the fabric.

12. A two-faced moisture management fabric for wearing apparel, comprising at least one hydrophobic yarn of essentially 100 percent hydrophobic fibers, and the composite yarn according to claim 2, the hydrophobic yarn being concentrated in the body contacting face of the fabric, and the composite yarn being concentrated in an outer face of the fabric.

13. A two-faced moisture management fabric for wearing apparel, comprising at least one hydrophobic yarn of essentially 100 percent hydrophobic fibers, and the composite yarn according to claim 3, the hydrophobic yarn being concentrated in the body contacting face of the fabric, and the composite yarn being concentrated in an outer face of the fabric.