US3854177A - Process and apparatus for texturing yarn - Google Patents

Abstract

Processes and apparatus are disclosed for texturing yarn of continuous filaments at high speed to increase the bulk. A stream of hot compressible fluid, such as heated air or steam, is jetted to form a turbulent region. The filaments are crimped by passing them through the turbulent region, removing them from the fluid stream by a screen or other foraminous surface, and cooling them with fluid on the screen to set the crimp prior to imposing any substantial tension on the filaments. Yarn feed and take-up speeds, and other conditions are adjusted to provide the desired crimp as illustrated in the examples.

Description

United States Pat nt 1191 Breen et al.

[ Dec. 17,1974.

PROCESS AND APPARATUS FOR I TEXTURING YARN Inventors: Alvin L. BreemHerbertG.

Lauterbach, both of Wilmington,

Del.

Assignee: E. I. du Pont de Nemours and Company, Wilmington, Del.

Filed: Apr. 15', 1968 Appl. No: 721,403

Related US. Application Data Continuation-impart of Ser. No. 43,897, July I9, 1960, abandoned, which is a continuation-in-part of Ser, No. 698,103, Nov. 22, 1957, abandoned.

Us. c1. 28/1.4,' 28/7212 Int. Cl D02g 1/16 Field of Search 28/l.4, 72.12; 57/34 B References Cited UNITED STATES PATENTS 4/1968 Richmond et al. 28/72.l2 X

FOREIGN PATENTS OR APPLICATIONS 1,225,587 2/1960 France 57/34 B Primary Examiner-Louis K. Rimrodt [5 7 ABSTRACT Processes and apparatus are disclosed for texturing yarn of continuous filaments at high speed to increase the bulk. A stream of hot compressible fluid, such as heated air or steam, is jetted to form a turbulent re- .gion. The filaments are crimped by passing them through the turbulent region, removing them from the fluid stream by a screen or other foraminous surface, and cooling them with fluid on the screen to set the crimp prior to imposing any substantial tension on the filaments. Yarn feed and take-up speeds, and other conditions are adjusted to provide the desired crimp as illustrated in the examples.

10 Claims, 18 Drawing Figures PATENIELJZC I 71874 ,177

SHEET 20F 4 INVENTORS ALVIN L. BREEN HERBERT G LAUTERBACH ATTORNEY PMENIEQBE 3.854.177

SHEET 4 OF 4 INVENTORS ALVIN L. BREEN HERBERT G. LAUTERBACH ATTORNEY 1 PROCESS AND APPARATUS FOR TEXTURING YARN REFERENCES TO RELATED APPLICATIONS This is a continuation-in-part of copending application Ser. No. 43,897 filed July 19, 1960, and now abandoned as a continuationin-part of application Ser. No. 698,103, filed Nov. 22, 1957 and now abandoned.

- This invention relates to an improved fluid texturing process and apparatus for producing bulky yarn, tow, or the like, and especially adapted for producing yarn of substantially continuous individually crimped filaments having a random three-dimensional curvilinear configuration and excellent level dyeing characteristics, including an unusually rapid dyeing rate, of the type disclosed and claimed in our U.S. Pat. No. 3,186,155, issued June 1, 1965, as a continuation-inpart of said Ser. No. 698,103.

Artificial fibers are normally produced most easily as continuous filaments. These continuous filament yarns are very strong because of the absence of loose ends that are unable to transmit imposed stresses. Their extreme uniformity and lack of discontinuity, however, makes conventional continuous synthetic filament yarns much more dense than yarns made from synthetic staple fibers. The production of yam from staple fibers, however, is time consuming and requires a complex series of operations to crimp the fibers, align the fibers into an elongated bundle and then to draw the bundle to successively smaller diameters. The final spinning operation, which involves a high degree of twist, finally binds these discontinuous fibers together to produce a coherent yarn with considerably increased bulk. The occluded air spaces give them a lightness,

covering power, and warmth-giving bulk not normally possible with continuous filament yarns. Thus, to get staple fibers that can be processed on conventional wool or cotton spinning equipment, it has been the practice to cut continuous filament yarns such as rayon, acetate, nylon, as well as the polyacrylic and polyester fibers into short lengths for spinning into staple yarn.

Recent developments in the textile industry have provided useful routes for improving the bulk andcovering power and recoverable elongation of continuous filament yarns without resorting to the staple spinning systems of the prior art. A well-known process for making stretch yarn involves the steps of twisting, heat-setting and then backtwisting to a low final twist level. Another yarn of improved bulk is prepared commercially by the steps of twisting, heat-setting and backtwisting on-the-- run using a false-twisting apparatus. This end product can be further modified by hot relaxing to improve the bulk and handle. Still another bulk yarn is being prepared by the well-known stuffer box technique whereinthe yarn is steamed to heat-set while his in a com pressed state in the stuffer box.

All of these yarns of the prior art are produced by a process which has the common elements of deforming the yarn mechanically and then heat-setting either with or without an after-relaxation step. It is not until the recently disclosed product in U.S. Pat. No. 2,783,609 to Breen, issued Mar. 5, 1957, and its process of manufacture became known that an entirely new technique became available for improving the bulk of continuous filament yarns. This technique involves exposing a filamentary material to a rapidly moving. turbulent fluid,

tion continuously along the filaments. The process is thereby inducing a multitude of crunodal filament loops at random intervals along the individual filaments. These loops and snarls of entangled loops increase the bulk of the continuous filament yarns considerably and result in fabrics of improved cover, bulk, handle and the like. With the invention of Breen, a new tool is available for the bulking of filamentary structures, i.e., a turbulent fluid. Fluids, of course, have been used for yarn treating in many of the prior art operations such as drying, extracting, transporting and the like. Until the invention of Breen, however, they had not been used to entangle, convolute and bulk a filamentary material.'[t has now been discovered, however, that a new process utilizing the turbulent fluid technique results in new yarn products that have certain unique properties not heretofore disclosed in the art.

It is an object of the present invention therefore to provide an improved process for producing continuous filaments and continuous filament yarn having .a bulkiness greater than staple yarn spun from comparable fibers. Another object is to provide an improved process cess for preparing continuous filament yam having a bulk greater'than that of comparable stapleyam without abrading or cutting the constituent filaments. A still further object is to provide such a; process which is suitable for economically treating ordinary multifilament continuous yarn at unusually high speeds. Other objects include apparatus for texturing multifilament yam to provide greater bulk. Other objects will appear as the description of the invention proceeds.

In the process of this invention, yarn comprising plasticizablefilaments is textured with compressible fluid heated to a temperature which will plasticize the filaments to impart a persistent crimp having a ramdom, three-dimensional, curvilinear, extensible configuraparticularly effective for crimping the thermoplastic synthetic linear polymer filaments commonly used in commercial yarns, e.g., nylon filaments,- polyester filaments and acrylic filaments. The heated fluid is jetted as a high velocity stream to form a turbulent plasticizing zone of heated fluid. The yarnfilaments are fed at high velocity into the turbulent zone, are continuously forwarded and crimped by the turbulent action of the.

heated fluid while the filaments are in a plasticized con= dition, are received on a moving surface to remove the filaments from the heated fluid in a substantially tensionle'ss state, are conveyed on the moving surface through a stream of coolingfluid to set the crimp in the filaments, and the cooled filaments are finally taken up they remain in this condition until after deposition on the moving surface. The yarn can be supplied in a plas' tic as-spun condition, e.g. 'it can be fed directly from a melt-spinning operation while still in a heat-plasticized condition, or it can be green cellulose acetate which has not been completely dried afterspinning. The yarn can be preplasticized with heat or solvent as it is fed to the turbulent zone. Preplasticization with heat can be accomplished by feeding over a heated roll or other surface, by passing the yarn through a heated atmosphere such as hot air or steam, by exposing it to infrared radiation, or even by forwarding it with an auxiliary preheating jet. The yarn can also be plasticized in the stream of compressible fluid used for crimping it, e.g., the fluid can be steam or air at a sufficiently high .temperature to soften thermoplastic filaments. In any case, the heated fluid must retain the filaments in a plasticized condition until they have been crimped and deposited on the moving surface.

Conventional conveyors used in processing yarn or tow provide suitable moving surfaces having multiple perforations or indentations which serve to separate the crimped filaments from the turbulent fluid. The moving surface for removing the filaments from the heated fluid may be embodied in a drum, disc, belt or similar member having a sieve or screen or slotted surface to receive the filaments. The moving surface may be used to convey the filaments away from the turbulent stream to a separate position where the filaments are cooled prior to being removed from the surface.

The crimp developed in the fibrous structure is set on tion;-

the moving surface before appreciable tension is applied in taking up'the structure from the surface. Setting by cooling, or removal of plasticizing solvent can be accomplished by providing a sufficient length and/or time of passage on the moving surface after leaving the turbulent stream, or with such auxiliary means as a stream of cooling or drying fluid, cooling of the foraminous surface, or otherwise refrigerating or quenching,

ting of the crimp.

The process is suitable for producing unusually desirable crimped yarn at exceptionally highspeeds. Yarn is .readily processed at feed rates of 3,000 or more yards per'minute. As will] be illustrated subsequently in this specification, the process also provides important advantages at the much lower feed rates which have been used previously for bulking yarn. The forwarding action of the texturing stream is adjustedrelative to the feed rate to provide for the desired amount of crimping. Pressures of 10 to 500 pounds per square inch gauge (psig.) are generally suitable, depending upon the feed rate and, of course, the nozzle design, material processed, denier per filament and total yarn denier. Feed rates of 12 percent to 100 percent greater than the take-up speed of the crimped yarn, after setting on the moving surface, are most useful.

The invention and the manner of carrying it out will be more clearly understood by reference to the drawings in which,

FIG. I is a schematic perspective view of apparatus suitable for practicing the process of this invention,

FIG. 2 is a schematic perspective view of a variation of this equipment suitable for stretching the yarn and bulking it in successive steps without intermediate packaging,

FIG. 3 is a schematic perspective view of similar equipment adapted to spinning, drawing and bulking in successive steps without intermediate handling or packaging,

or evaporating or extracting solvent, to accelerate set- FIG. 13 is a longitudinal view of a multifilament yarn produced by this invention;

FIGS. 14 and 15 show variations of the multifilament yarn produced by this invention;

FIG. 16 is a cross-sectional view of a fiber having a nonround cross-section of a type preferred for prepara-.

tion of a carpet yarn; I

FIG. 17 is a longitudinal view of a single filamentshowing a twisted configuration obtained in accordance with this invention from a fiber of nonround cross-section; and

FIG. 18 is a schematic perspective view of an addi- I tional embodiment of apparatus suitable for practicing the process of this invention and which-also illustrates the process of feeding multiple yarn ends for simultaneous treatment, followed by separation of the treated yarns.

In FIG. 1 the moving threadline of yarn to be treated I (31) is passed through guide (32), between feed rolls (33 and 34), over guide (35), through fluid jet (36), is received on moving screen (37), and is conveyed through a stream of cooling fluid from nozzle (38) to set the crimp. The moving-screen is shown in the form of a horizontal disc supported on a rotating shaft (39). A screen in the form of a movingbelt or revolving cylinder can obviously be used instead of the disc shown. Also, the jet can discharge horizontally onto a verticalmoving screen, instead of downwardly as shown, or at any other convenient angle. One or both 0f the feed rolls (33 and 34) can be heated topreplasticize the yarn or any conventional heating means can be used, e.g., by passing the yarn over a heated metal shoe. .The treated yarn is subsequently removed from the screen, passing throughguide (40) directly to guide (43) or being forwarded by rolls (41 and 42). Traverse guide (44) may be used to distribute the bulky yarn on package (46) driven byroll (45).

FIG. 2 shows undrawn yarn (51) passing 'continuously between feed rolls (52 and 53) around pin (54) to draw roll (55) having cylindrical surface (56). Several wraps of yam are placed about surface (56) and idler roll (57). The yarn is then passed continuously through guide (58) to jet (59) and crimp set on screensurfaced drurn'(60). The drum is rotated on shaft (61) to carry the bulked yarn away from the jet stream, and the yarn is withdrawn from the drum at a subsequent position in its rotation by take-off rolls (62 and 63). From the take-off rolls the bulky yarn is passed continuously through traverse guide (64) to package (65) driven by roll (66). The screensurfaced drum is provided with means, including exhaust port (67) and ductwork (68), for removing fluid from within the drum by exhaust apparatus (not shown). This is arranged to withdraw the heated fluid discharged by the jet (59), and to provide a stream of cooling fluid through which the yarn is conveyed prior to removal by the take-off rolls.

In FIG. 3, filaments (70) from spinneret (71), quenched asymmetrically by cold fluid directed to the face of the spinneret by fluid nozzle (72), are conmoving at higher speed. The yarn is fed through guides (78 and 79) and jet (80), where a jet stream of heated fluid acts to separate, crimp and forward the filaments onto screen-surfaced drum (82). The filaments are conveyed under a stream of cooling fluid from nozzle (83) to set the crimp, and the cooled filaments are then taken off of the screen-surfaced drum around guide roll (84) by rolls (85 and 86) and wound up.

FIG. 4 is a jet suitable for the practice of this invention, consisting of body member orifice member (96), held in place by clamp (97), and screw (98). The passage through orifice member (96) consists of cylindrical opening (100), connecting with concentric cylindrical opening (101), and outwardly tapered opening (99), characterized by the angle a. Yarn tube member FIG. 6 is a similar jet consisting of body member yarn guide (116) and orifice (117). Compressible fluid enters the body member through opening (118) and the yarn enters through opening (119). The nipple of yarn guide (116) extends into the entrance of venturi-shaped orifice (117) and is slightly off-center with respect to the orifice axis.

FIG. 7 is a similar jet particularly adaptable to multiple end operation where precise temperature control is desired from position to position. It consists of jet body (121) with opening (122) for the turbulent fluid, and replaceable orifice (123). Yarn guide member (124), provided with yarn opening (125), is machined so that tip (128) is eccentric to the jet axis. As shown, the longitudinal axis of the cylindrical yarn passageway is laterally offset with respect to the longitudinal axis of the venturi-shaped jet orifice by an amount slightly less than half the difference in diameters of the most restricted portion of the jet orifice and of the cylindrical yam passageway. The tip' (128) extends into the converging entrance of the orifice but not into the most restricted portion. Jet body (121) is sealed in manifold I (129) by gaskets (126) and flanges (127).

FIG. 8 is a simplified jet suitablefor the practice of this invention consisting of body member (130) with drilled holes (131, 141) to provide a T-shaped intersectube (132) by virtue of the electrical resistance of the tubing. Similarly, highamperage current applied between lugs (138) and 139) provides additional heating to the turbulent fluid exhausting in a countercurrent direction to the threadline moving from toward (131). .This arrangement preheats the yarn so that it is in a desirably plasticized state as it traverses the zone of greatest turbulence between (131) and(141). Turbulent fluid exhausting preferentially from orifice (141) produces the desired bulking action. Insulation prevents excessive heat loss from tubes (132) and (134) and also tends to support these fragile elements. This unit is particularly useful for treating yarns at very high speeds in the range of 500l,000 ypm or more. FIG. 9 shows the intersecting holes of the jet in cross section of FIG. 8.

It is to be understood that other devices'employing heated plates or rolls may be substituted for the pre heater of FIG. 8. Similarly the preheating fluid could be a hot gas applied by an auxiliary nozzle or a hot liquid applied in an open bath or semiconfining' tube. Such devices likewise may be made as an integral part of any of the fluid nozzles disclosed'as suitable for use in the process.

FIG. 10 shows one form of jet particularly useful for the practice of the process of this invention as indicated in FIG. 3 where the thread line being treated is taken directly from a spinning operation. In this case, body member (150) is split into two similar'portions. Likewise, yam guide member (143) is split into similar parts, laying open the yarn passage (144) and orifice (145). For stringup, these parts are held in the open position by hinge (146). During the bulking operation, the parts are held in a closed position by hook (147) and pin (148). Screws (149) are used to adjust the depth of yarn guide member (143) within body piece (150). An adjustment of the opposing yarn guide members (143) to slightly differing depths produces a desirable eccentricity of the turbulent fluid flow pattern. Other forms of jets similar in principle to FIG. 10 but having rotating or sliding parts or other mechanisms to provide access to the turbulent fluid chamber are like wise useful in the process of this invention.

FIG. l1 is a thin cross section of the yarn produced showing short lengths of filaments in randomly disposed arrangement. Fibers at points a show a random wrapping effect which in some cases improves the cohesiveness of the yarn bundle without inhibiting its bulkiness and stretch properties. The freedom from protruding loops indicated here gives desirable improvement in yarn handling characteristics and freedom from snagging problems in end use form. The yarn cross section was made by supporting the sample in a transparent mounting of polymethyl methacrylate prior to sectioning so as to hold the short lengths of fibers in position.

FIG. 12 is an illustration of the individual filaments of the product..Pointsc show what appear to be angular crimp form. This is intended to represent a region where the filament path is in the general direction perpendicular to the plane of the illustration'causing apparent distortion of the curvilinear form.

The above statements apply similarly to the filaments comprising the yarns illustrated in FIGS. l3, l4 and 15.

For certain uses where subdued luster and tactile dryness are desired thepreferred product of this invention should be made from fibers having a nonround shape of critically selected character. In carpet yarns, for example, it has been found that the approximately symmetrical cross-section form indicated in FIG. 16 is preferred. This is defined in terms of a modification ratio 7 which is the ratio of the diameter of the enscribing circle D to the inscribed circle d.

A desirable property of the product of this invention based on these nonround fiber forms is illustrated in FIG. 17. Here the fiber hasnot only the random three-- dimensional, nonhelical, curvilinear configuration, but is also formed into a randomly twisted configuration, portions of which are in an S direction with other portions being in a Z direction.

To determine the extent of the random twist modification of the individual fiber, a specimen is mounted between microscope slides with sufficient tension to hold the fiber axis in an approximately straight condition but a tension low enough that the twist is not appreciably reduced. The angle is then measured between imaginary lines following theoutermost points of the filaments and the filament axis at a number of points sufficient to provide a meaningful average. This average angle should be at least 1. There will be points where the angle is essentially zero where the twist reverses direction. Other points are found where the angle is considerably greater than the average value. In well-modified samples, maximum values in the order of 30 are observed and the average may be as much as 5 or more.

since the twist of each filament is random along its length, a yarn made up of a group of these filaments is prevented from packing in a closely nested configuration. This is true even when considerable tension is applied to the yarn sufficient to straighten the random curvilinear crimp configuration. This latter property is particularly useful in increasing the bulk of tightly woven fabrics where loom tension and fabric construction tends to reduce the bulking effect due to crimp. The ramdom twist is likewise useful in highly-crimped pile yarns of bulky knit structures where it tends to reduce objectionable glitter or luster associated with light reflection from the fiber surfaces.

The process described and illustrated in FIGS. 1, 2 i

and 3 for a single yarn can also be carried out with a feed of multiple yarn ends. By feeding two or more' yarns, instead of the single yarn illustrated, a doubled,

treated yarn can be obtained. by using a multiple feed of different types of fibers, a blend of the fibers in the treated yarn is obtained. On the other hand, the yarns can be reseparated after treatment, if desired, and woundinto separate packages in the manner illustrated in FIG. 18. Three yarn ends (160, 161 and 162) from separate supply sources, such as bobbins or spinnerets, are brought together through guide (164) to form a single bundle of filaments (165). The filament bundle is fed by feed rolls (166 and 167) through guide (168) to fluid jet (170) and is then deposited on a moving screen (171). Any of the combinations of jets and crimpsetting surfaces discussed can be used. In. FIG. 18, a

screen in the form of a continuous belt passing around rotating rolls (172) and (173) is illustrated. The belt carries the treated filament bundle away from the aspirating jet stream to a point where the filaments are sufficiently set for removal. The bundle is then removed from the screen through guide (175) to be wound up or otherwise collected. If desired,the bundle taken off between rolls (178 and 179), and yarn (16 2) is forwarded by rolls (180 and 181).

In the preferred process of this invention, filaments and yarns meeting the stated objects are provided by a process in which a stream of a compressible fluid at a temperature above the second order transition temperature of the polymer of which the filament is made, and preferably at least about 300 F., is vigorously jetted to form a turbulent plasticizing region which will maintain the yarn temperature above the cold point as. described more fully hereinafter and below the melting point of the yarn. The yarn or other'strand of filaments to be treated is positively fed at a rate greater than the.

yarn take-up speed into the fluid plasticizing stream so that the yarn is supported by it and individual filaments are separated from each other and crimped individually while whipping about in the hot turbulent plasticizing region and are then removed from the fluid stream by a screen or other foraminoussurface where they areaments are cooled on this screen .before reaching thetake-up rolls to prvent further plastic flow and to insure retention of the crimp while maintaining the yarn in-a substantially relaxed and tensionless condition. After cooling, the yarn may be tensionedto remove any fiber loops, eliminate any packing of filaments and to improve thebulking characteristics of the yarn. Tensioning is desirable also for forming a suitable package on any windup device. Tension'applied-in taking up the yarn from the screen or in winding the yarn on a package appears to cause some temporary removal of fiber crimp, but this crimp is substantially recovered when the yarn is relaxed and boiled-off. Stable crunodalloops are avoided or at least kept to a minimum by control of the process conditions since such entangled loops prevent maximum bulk from being obtained in the yarns. The crimped yam, of course, may be cut into staple after removal from the screen. This process, therefore, provides a highly productive way of crimping tow which is to be used in staple products. This process may also be used for setting dyes in the yam. A yarn padded with dyes may be either treated with a turbulent fluid to set the dyes in the fiber by diffusion through the fiber or it may be treated with a turbulent fluid to simultaneouslybulk the yarn and set the dyes.

Bulky yarn can be prepared by the process of this invention from any plasticizable fiber. The process is applicable primarily to continuous filament yarns and multifilament yarns in particular although monofilaments can also be crimped in the same manner. Staple yarns can also be processed to give products of greatly increased crimp and bulk particularly in the surface fiber.

The products of this invention are different in fundamental physical structure from any of the bulked yarns described in prior art. During the jetting treatment, a

most surprising shrinkage of the filaments and relaxation of the molecules making up the filaments occur.

When jetted under optimm conditions, this shrinkage and relaxation far exceeds that which occurs when the yarn is exposed to the same fluid at the same temperature and under zero tension for a long period of time without agitation. This dynamic relaxation is responsible for a considerable amount of deorientation of the molecules and an increase in crystallinity. In addition, there is a large increase in dye receptivity. Thus a practical way has been found to accomplish a very valuable reorganization of the molecular structure of the filament which would otherwise be utterly impossible to accomplish.

The higher filament temperatures under relaxed conditions and the repeated stressing cause the amorphous molecular structure to open up giving more lateral space between molecules and greater distance between crystallites along the fiber axis. The great changes in the amorphous molecular structure are shown clearly by low angle x-ray patterns using the techniques described by W. O. Statton, J. Polymer Sci. 22, 385 (1956'). This new opened-up condition, plus the deorientation which occurs, gives fibers with greatly improved dyeing rate not heretofore encountered in textile yarns. The dyeing rate is increased about 50 percent to 150 percent by the process of this invention and there is no change in the chemical composition of the fiber during treatment. Of course, moderate improvements in dye rate have been shown in prior art by relaxed'heat treatment, but increases in dye rate greater than 50 percent have not heretofore been encountered. in addition, the rapid turbulent heating of extremely short duration in the present process permits much higher filament surface temperatures to be obtained since there is no danger that interiors of filamentswill be heated above their melting point.

All commercial procedures for manufacturing synthetic fibers inadvertently subject a portion of the yarn or certain segments of a portion of the yarn and filaments to plucks or other stresses as, for example, when processing with fluids or passing over guides, which causes these yarns or segments to dye at a different rate and/or to a different depth relative to the bulk of the yarn. The dynamic relaxation employed in this inven-' tion eliminates most of the nonuniforrnities in structure caused by these plucks and stress and thus the treated yarns have much more uniform dyeability along and across the bundle than can -be obtained by nonturbulent radiant heating or by contact with heated mechanical surfaces. The yarns prepared by the process of this invention therefore have better dyeing uniformity than bulk yarns prepared by the twist heat-set method, by stuffer-box crimping, or by other processes known in the art.

The products of this invention assume a threedimensional, non-helical, random, curvilinear configuration.

these have predominantly a helical and regular type of filamentary deformation. It is different also from those prepared by the well-known stuffer box technique, since the latter are characterized by a regular and reversing or saw-tooth planar type of crimp. Because of the turbulent and random fluid currentsin the treating chamber of the subject process, the crimp in the submers such as polytetrafluorethylene and polymonochL.

orotrifluoroethylene and cellulose derivatives such as cellulose acetate.

This structure is different from the bulked materials v prepared by the various twist-setting operations, sinceject products is three-dimensional and random in crimp a confined space results in a very high crimp level, and a curvilinear rather than rectilinear, saw-tooth, helical or crumodal loop type of filamentary configuration.

The crimp is permanent to normal fiber processing conditions and will persist in filaments taken from the yarn bundle. On exposure to hot water, marked increases in crimp amplitude and frequency are obtained. The useful products of this invention have a crimp level in excess of five per inch, and preferably above 10 per inch. They may even be as high as or crimps per inch.

The process of this inventioncan be used to crimp and bulk any natural or synthetic plasticizable filamentary material. Examples of such filamentary materials include polyamides, such as polysebacamide, polyhexamethylene adipamide, polyundecanoiamide, polycaproamide, and copolyamides; polyesters and copolyesters, such as the condensation products of ethylene gly col with terephthalic acid (polyethylene terephalate) or 2,6naphthalic acid (polyethylene 2,6-naphthalate), ethylene glycol with a /10 mixture of terephthaliclisophthalic acids, ethylene glycol with a 98/2 mixture of terephthalic/S-(sodium sulfo)-isophthallic acids, poly(diphenylolpropane carbonate), l,4-bis(hydroxymethyl) cyclohexane with terephthalic acid to include trans/cis mixtures, and poly(diphenylolpropane isophthalate); acrylonitrile polymers, such as polyacrylonitrile and copolymers of acrylonitrile with vinylidene chloride, vinyl chloride, methyl acrylate; or any of the comonomers listed in Jacobson US. Pat. No. 2,436,926 or Millhiser US. Pat. No. 2,837,501; vinyl chloride and vinylidene chloride polymers and copolymers; polyurethanes, polyester amides, polyethylenes and polypropylenes (both linear and branched), polycarbonates; fluorinated ethylene polymers and copoly- While the preferred form of material is continuous filaments, the process and resultant improvements occur with staple yarns as well. Both types of materials can be made into bulky yarns and fabrics having improved bulk, covering power (opacity) and hand.

This process is useful for both monofilament and multifilament yarns in textile deniers as well as' the heavier carpet and industrial yarn sizes either singly or combined in the form of a heavy tow. Fine count and heavy count staple yarns can be processed both as singles and plied. The process and product are also not restricted in the case of the synthetic materials to any one parrticular type of filament cross section. Cruciform, Y-shaped, delta-shaped, ribbon, and dumbbell and other such filamentary cross sections can be processed at least as well as round filaments and usually contribute still more bulk than is obtained with round filament s.

The turbulent fluid used to treat the or vapor capable of plasticizing action on the yarn provided that it has a temperature above the second order transition temperature of the filament or that there is an equivalent softening effect by solvent action at the temperature used. Hot air will give sufficient plasticization in the turbulent region for many fibers although it may be desirable for certain fibers to supplement the temperature effect with an auxiliary plasticizing mefilamentary ma terial maybe air, steam or any other compressible fluid dium. Actually, steam'is preferentially used in the subject process since it is a cheap and convenient source of a high pressure fluid with a compound plasticizing action.

The temperature of the fluid medium must be regulated so that the yarn temperature does not reach the melting point of the fiber. However, with fibers made from fusible polymers, the most effective bulking and the greatest productivity is obtained when the temperature of the turbulent fluid is above the melting point of the fiber. In this case the yarn speeds should be great enough so that melting does not occur. Because of the great turbulence and the high heat, yarns are heated rapidly. Temperatures lower than the second order transition temperature (T,,) of the yarn material should usually not be employed because under these conditions the crimping or bulking of the filaments is not permanent and utility of the fibers is reduced.

One of the essential elements of the process is that the'filaments or yarn must be inherently elastic but must be rendered non-elastic and plastic in the turbulent atmosphere. The plastic condition may be brought about by the temperature of the compressible fluid or in the filaments. In any case, the plastic condition of the filaments must be temporary and transitory. The-term the range of l to ypm may be'considered the minijetted at a velocity of at least 1/2 sonic velocity. To'

plasticizing or plastic is intended to meanthat the conditions to which the term relates are such that the filaments are in a temporary flaccid, non-elastic, deformable condition. After the plasticizing conditions are removed such as by lowering the temperature, chilling, removing the solvent, or smilar considerations, the filaments and yarns must return to their normal elastic state. The use of an inert compressible fluid such as air mum useful yarn temperature for the process of this invention.

For good bulking action theheated fluid should be achieve maximum bulking. or crimping it is desirable that the tension of the yarn subject to the turbulent fluid medium be maintained below about 0.2

gm./denier. Preferably yarn tension duringthe bulking is maintained between about 0.0001 and about 0.01

gm./denier. For the most efficient bulking action at thehighest degree of bulk and highest throughput of yarn, tensions of the yarn should be maintained between about 0.0005 and about 0.005 gm./denier. 'This low tension in the yarn is regulated by controlling the yarn feed rate and the degree of forwarding or braking action of the fluid plasticizing medium. This forwarding actiondepends in'part on the distance the yarn travels in the fluid. The treated yarn should be removed from the fluid before an undesirable tension is applied. Generally, the yarn should remain in the turbulent stream for a distance of less than 6 inches. In high speed operation, it is desirable that the yarn be removed from the or steam under conditions which do not plasticize,

soften, or render the filaments non-elastic does not fall within the scope of the invention unless thefeed yarn isintroduced in a plastic state, such as in the case of there is sufficient residual volatile solvent in the filaments. It will also be apparent that large amounts of non-volatile plasticizers such as dibutyl phthalate, tricresyl phosphate, oils, plasticizing resins, etc., are relatively permanent and when these are present the yams will not return to an elastic condition and should be avoided except for special purposes.

At high speeds and with certain polymers, the fiber temperature should be well above the second order transition temperature. A preferred minimum temperature defined as a cold point is given by J. W. Ballou and J. C. Smith in the Journal of Applied Physics, Volume 20, page 499 (1949). The cold point is the second inflection in the sonic modulus-temperature curve for the polymer or fiber in' question. In general, this temperature may be C. or more above the second order transition temperature.

The temperature of the filamentary structure is difficult to measure under the usual working conditions, i.e., there may be a temperature gradient across a given filament on the yarn bundle. At high speed it is indicated that the surface temperature of the fiber being turbulent stream within 2 inches after issuing from the jet, and preferablywithin 1/2 inch of the outlet of the jet orifice.

A moving surface, preferably a screensurface, is

used to receive a strand aftertreatment to remove it from the turbulent stream of plasticizing fluid. It can be in the form of a belt, a cylinderor a disc, or the nip between two such surfaces moving in such direction as to remove the yarn from the turbulent region. Basically, these receivin'gsurfaces serve to convey the crimped yarn from the turbulent plasticizing zone while maintaining the crimped material in a tensionless condition. Once it is removed from the turbulent medium, suitable cooling means can be used to set the crimp. Asuitable surface may be a metal screen made, for example, of stainless steel. It may be plastic, glass, ceramic, or other material. It may also be a perforated sheet or belt, parallel wires or the like. The perforations can be in the form of holes, slots, that can be uniform or of varying dimensions.

Yarn feed speed can be varied over a considerable range depending on the material, temperature, denier,

' degree of bulking, tension and other variables. For ecoand higher.

The temperature of the heating fluid must be high enough so that either alone or in combination with some auxiliary plasticizing. component, e. g,, water, acetone or other solvent, it will soften or plasticize the filamentary material passing through the heating area. The optimum temperature, of course, varies depending upon the material being treated, the form of the material being treated,-'i.e., staple or continuous filament, the denier or yarn size, the rateof throughput, the degree of turbulence and/or pressure of the treating fluid, the design of the treating chamber, and the degree of crimping desired. The temperature can range as high as 700 F. or more and a preferred range is 400600. F. The controlling factors are the characteristics of the material being treated and the temperature actually reached by the filamentary material during treatment; The yarn temperature during the crimping operation should exceed. the second order transition temperature to insure permanence of crimp. The true. upper limit,

of course, is the temperature at which objectionable melting and/or-chemical degradation of a given yarn takes place.

There a number of means and apparatus whereby a turbulent stream of fluid can be produced. Suitable jets or devices for treating a filamentary material with a turbulent plasticizing fluid to achieve the improvements of this invention are described in Breen US. Pat. Nos. 2,783,609, 2,852,906 and 2,869,967, in Belgium Pat. No. 581,303, in Belgium Pat. No. 573,230, and in Hallden and Murenbeeld US. Pat. No. 3,005,251, as well as those in FIGS. 4 through 10. v

The crimped yarns are cooled after treatment in the turbulent plasticizing fluid and prior to any further operation that imposes tension on the yarn bundle. This quenching, cooling, or freezing operation locks in the three-dimensional, random, curvilinear configuration imposed on the various filamentary elements by the hot turbulent fluid. This quenching operation should prefe'rably cool the yarn below the second order transition temperature, T,,. After cooling, the yarn can be subjected to normal processing tensions and woundinto any of the conventional yarn packages. This quenching below 2.0 tpi. and preferably below 1.0 tpi. Yarns of I higher twist levels can obviously be processed, however, the tendency is for the formation of stable loops and filament intertangling at the expense of bulk and extensibility of the yarn bundle thus the yarn bundles become increasingly compact as the twist level rises. Obviously, the twist level of the feed yarn must be much higher if staple yarns are processed. The discontinuous nature of the fibers seems to minimize the formation of an objectionable degree of filament looping and yarn bundle compacting.

The process is well adapted for using a number of ends of yarn in the same jet. Thus, it is possible to pass two to five or more ends through a single jet at the same time. The resulting yarn may have the ends well blended or it may have bulked ends which will be d'istinctly separate and independently windable depending on the processing conditions. Two or more yarns may also be treated using different tensions or feed rates so as to produce a tensionstable bulky yarn with extensibility confined to that of the shorter member. Likewise, two different types of yarn such as nylon and rayon may be passed through the jet. The differential shrinkage and heat-setting of the two types of yarn provides many interesting effects which are desirable for esthetic reasons in textile materials. The crimp of the product is exoperation can be carried out afterv the yarn has been removed from the foraminous surface by piddling into a silver can or onto a moving belt but from an economic or roll. Passage of the yarn through a suitable liquid bath will also cool the yarn adequately. The preferred embodiment, however, is the use of a flow of a coolingfluid, preferably a gas. This can be in the form of a jet that impinges the gas on the yarn bundle. The cooling jet may be at room temperature or even refrigerated.

The yarn feed should be adjusted so that the tension in the processing zone is extremely low as indicated previously. The overfeed rate can be as high as 250 percent or higher but for most yarns this value is frornlO percent to 100 percent, above 30% being preferable for many polymers.

The feed pressure of the hot plasticizing fluid'will depend on the degree of turbulence desired, feed speed, yarn denier, material being processed, design of jet and the like. Pressures in the range of 10 psig to 500 psig are useful while the preferred range is from 40-100 psig. Normally, economics will dictate that the optimum pressure is the lowest that still gives the desired degree of crimping.

It is preferred that continuous filament feed yarn tremely stable and is not removed by tensions up to the draw tension. The bulked yarns disclosed in U .S. Pat. No. 2,783,609 require a high degree of intertangling or twist in order to maintain their, bulk properties. The new yarns described here are stable and keep their bulk even .when there is no entanglement or appreciable twist. Monofilament may be treated in a similar fashion to obtain a single crimped continuous filament. It is alsounderstood that any treatment of yarns herein disclosed is to be construed as being applicable also to single filaments although for reasons of economy bundles of filaments or yarns are treated.

The process of this invention can produce a gross increase in the bulk of the filamentary structures. The comparison of the starting denier to the final denier is a crude indication of the bulk increase. However, a better measure of bulk can be obtained by determining the volume of a definite weight of yarn while under pressure. This measurement of bulk under compressional I loads'is useful for estimating the bulk which a yarn will have when fabricated into carpet or otherfabrics. lt correlates very well, for example, with subjective impressions obtained by feeling a carpet with the fingers.

For the purpose of this invention bulk is. therefore, measured under a pressure of 3.1 lbs/sq. in. The crimped yarn samples are measured in the untwisted state, that is, with less than one turn per inch in the gross yarn. Before testing, the untwisted yarn is given a hot wet relaxed treatment to develop maximum bulk and is then dried and conditioned at F. and 65 percontain little or-no twist. The twist level should be cent relative humidity. Weighed samples of exactly 2.0 g.-are then cut into 1/2 to 3/4 inch pieces. The cut pieces are then dropped at random into a hollow stainless steel cylinder having an inside diameter of 1.008 inches. A round stainless steel piston of 1.000 inch diameter is then loweredslowly into the cylinder to'compress the yarn and finally to exert a pressure of 3.1 lbs./sq. in. on the top of the yarn sample. After maintaining this pressure for seconds, the volume of the compressed yarn is determined. The volume in cubic centimeters divided by the weight of the yarn in grams bulent plasticizing fluid medium, a considerable degree umes from 3 to 7 cc./g. 10

The synthetic filamentary materials to be treated by the process of this invention should preferably be in a high state of orientation to reduce pilling in the finished fabrics. Drawable filaments tend to snag and pull out of the fabrics. The resulting fuzz fibers then tend to windup into fuzz balls usually referred to as pills in the finished fabric. When the oriented filamentary structures are passed under low tension through the hot turof deorientation and crystallization occurs.

Because of the unusually large increase in crystallinity, during process, the final yarns have a break elongation that is much smaller than would be expected con paratus having several fluid entry ports spreadabout sidering the large degree in orientation. Similarly the tenacity changes less than expected. At the same time, the yarns have a surprisingly high dyeing rate. The net result is to obtain unusual bulky yarns having a desirable combination of low elongation, low pilling tendency and rapid dyeability. Pilling is avoided because yarns of low elongation do not easily draw or pull out of theyarn or fabric when snagged to give long fuzz fibers. These undesirable fuzz fibers cause pilling by winding and entangling around one another until balls of fuzz are formed. Of course, yarns with low elongations can be obtained in other bulk yarn processes by drawing the feed yarn adequately, but these highly drawn yarns then have relatively low dyeing rates.

In addition to the increase in relaxed yarn denier due to the convoluted form, the high degree of deorienta- 40 tion that accompanies the relaxation in a preferred process results in a gross increase in the filament denier of the yarn being treated. Some increase in denier, of course, accompanies almost any relaxation or bulking process, i.e., l-lO percent. The filament denier of the change in filament cross-sectional area rather than the gross overall bulk denier increase that comes about through the crimp contraction.

All of the jets useful in the process of this invention are characterized by an arrangement for the common exit of the turbulent fluid and the yarn bundle being treated. The turbulent fluid in all casesexhausts at high velocity relative to the yarn velocity. One surprising quality common to all jets which are adjustable is the need for careful adjustment of the jet for optimum bulking action. The jet shown in FIG. 4iseasily adjusted by moving part 102 in or out with respect to part 95. A second adjustment is accomplished with the rotation of part 102 within the opening 104; In general, with heavy weight yarns, lip 105, on needle 103, should be withdrawn from the center position. For light denier yarns the optimum adjustment is with the lip beyond the center line of opening 100. The needle obstruction in the air flow also adds turbulence to the system which in some cases gives a superior product.

Jets shown in FIGS. 5, 6, 7 and 10 are also sensitive to adjustment. In general, the part (111, 116,124, or 143) introducing the yarn to the air stream should be slightly off-center with respect to the orifice axis for best bulking action. A angle a (FIG. 4) favored ease of adjustment for best bulking action. In the jet'of FIG. 8, the eccentricity factoris provided by the abrupt change of direction of the high velocity fluid as it enters the yarn passage from one side. A variation of this apthe periphery of the yarn passagewayis likewise made eccentric in its action of the yarn by using ports of dif-' ferent sizes and/or by disposing them in a preferred unsymmetrical grouping. Stationary baffles within the jet may be used similarly to provide the eccentric flow pattern.

The following examples are given by way of illustration and not limitation. It is to be understood that while they illustrate the use of certain synthetic polymeric square, rectangular, flat, star shaped, or those having three or more cusps and similar shapes. Likewise the denier, speed, temperature, screen speed and other considerations may vary widely within the limits given above.

EXAMPLE I Yarns of various denier and polymer composition are bulked with the apparatus illustrated in FIG. 1. The yarn is passed over a feed roll at various feed speeds as recorded in Table I just before entering the jet. As the yarn emerges from the jet, it impinges on a moving screen. The screen speed is also shown in Table I. As the yarn moves away from the jet on the moving screen, it is cooled to set the crimp. After the yarn is set adequately it is passed between the take-up rolls and then to a suitable windup.

TABLE I Examples A B C E F Polymer 66'- 6-6 2GT/Sl 2GT/Sl HPXGT 6 Nylon Denier 40 7O 70 lSO 2100 No. Filaments I3 34 50 50 34 112 Twist 0.5"2" 0.5Z 0 0 0.5Z" 0 Luster Semidull Semidull Semidull Semidull Semidull Bright Cross Section Trilobal Trilobal Trilobal Trilobal Round Round Tenacity (g/d) 4.9 6.2 3.2 2.3 3.2 1 8.] Break Elongation (7:) 44 54 6I 26 12 40 Initial Modulus (g/d) 14.5 14.7 44 51 27 Dyeing Rate (7r/l0 Min.) 1.05 1.45 L26" 3.36 0.74 Long Period (A) TABLE 1 Continued Examples A B C D E F Processing Conditions: Feed Speed 1000 566 1000 1039 633 200 Steam Temperature (F.) 550 556 500 427 580 435 Steam Pressure (psig) 40 38 50 50 50 40 Screen Speed (ypm) 40 33 45 33 40 40 7t Overfeed 33 47 75 34 26 100 Bulked Yarn gBoiled Off! u ed Denier (BYD) 72 112 170-190 113 228 4700 Tensioncd Denier (TYD) 48 80 110-120 95 188 Crimp Elongation (YCE) 7! 50 40 25-30 18 Crimps Per Inch 31 18-22 13 12 Tenacity (g/d) 4.5 4.3 3.0 1.7 1.8 6.5 Break Elongation (71) 65 70 50 46 38 70 Initial Modulus (gpd) 8.8 11.8 29 8.3 12 Dyeing Rate ('/(/10 Min.) 3.15 2.57 3.55 4.00 2.1- Specific Volume (cm./g.) 6.5 6.5 8.5 7.4 Long Period (A) 89 96 146 6-6 is pulylhex amethylene adipumide] parenthesis.

fi-Nylon is poly(epsilon cuproumidfl). Acid dyeing rate. Basic dyeing rule.

EXAMPLE II A fiber of a polymer of acrylonitrile' having 93.65 percent by weight acrylonitrile, 5.98 percent methylacrylate,and 0.37 percent styrene sulfonic acid is bulked by discharging onto a moving belt. The feed is 900 denier, 80 filament, 0.3 Z twist, semidull yarn with dogbone-shaped cross section filaments. The yarn is, processed using the general conditions described in Example I. The steam temperature in the jet is 510 F. and 75 psig. The yarn passes to the jet at 500 ypm. and impinges on the moving screen as it emerges from the jet. The yarn is carried along on the screen at 30 ypm. for about 24 inches during which it is cooled and crimp set. Then the yarn is continuously removed from the screen and passes over the takeup roll at 305 ypm. Thus, the overfeed is about 61 percent. Finally, the yarn is collected by piddling. The product is a very bulky yarn having a bulked denier of 1,848, a yarn crimp elongation of 48 percent, a tensioned yarn denier (at 0.1 g/d) of 1,248, and having 11 crimps/inch in the filaments. The boiled-off filaments from the bulked yarn had a tenacity of 2.7 g/d, 33 percent elongation at break, and an initial modulus of 35 g/d. (Feed yarn properties are 3.1 g/d tenacity, 34 percent elongation, and 33 g/d initial modulus.) Using the cylinder bulk test (as described previously) the yarn bulk before boil-off is 13.2 cc/g and the yarn bulk after boil-off is 10.8 cc/g.

EXAMAPLE III A yarn of poly(ethylene terephthalate) 70 denier/50 2GT/Sl is u copolymcr of poly(ethylene sulfisophthalate] with the mol fraction of the respective constituents being indicated in HPXGT is a 66/34 truns/cis mixture of isomers of 1.4-his (hydroxymethyl) cyclohexune and tcrephthalic acid.

trate the effect of temperature on resulting yarn bulk. The yarn has an initial denier of 70 and contains 50 filaments of trilobalcross section made froma basicdyeable poly(ethylene terephthalate) copolymer havfilaments (trilobal) is bulked with the apparatus illustrated in FIG. 1. Processing conditions are 550 ypm.- yarn feed speed, 550 F. steam at 50 psig., 45 ypm. screen speed, and 50 percent total overfeed. The bulked yarn has a tensioned (0.1 gpd.) denier of 117.1 a force to break of 227 g. at a breaking elongation of 76 percent. Specimens of the feed and the bulked yarn are dyed at 208 F. in a 4 percent Latyl Blue 4R bath with no carrier. Dye absorption at Min. is 19.3 percent for the feed yarn and 76.0 percent for the bulked yarn or about a 295 percent increase in dye rate as a result of the bulking process.

EXAMPLE iv I A series of yarns are made by bulking with the apparatus of FIG. 1 at various steam temperatures to illusing 2.0 mol per cent of the sodium salt of poly( ethylene sulfisophthalate). The zero twist feed yarn is fed to the jet illustrated in FIG. 5 at 1,000 ypm using 50 psig superheated steam at temperatures varying from 500 F. by the deviation shown in the following table. Screen speed is maintained at 45'ypm and windup tension at 7 grams. Bulked yarns of various deniers, strengths, and specific volumes (bulk) are obtained as shown in the following table. The bulk is determined under pressure as described previously.

TABLE II STEAM TEMPERATURE VS. BLJLKED YARN PROPERTIES I Temp. Deviation Bulked Yarn Break Bulk (F. from 500F.) Denier Strength (cc/Gm.) (Gms.)

Control Yarn 70 235 5.5

, EXAMPLE V It is possible to bulk yarn at very high rates of yarn 'feed. For example, feed'yam as described in Example IV, is melt-spun, drawn 4X and bulked in one continuous operation without any intermediate packaging, as

. illustrated schematically in FIG. 3. The screen consists conditions. Ranges in yarn properties for these specimens are shown in the following tablealong with similar data for the unbulked feed yarn.

Yarn wound under l-g. tension on a spool with a slot of known volume. The weight of yarn required to fill this slot is used to calculate hulk specific volume.

Yarn is dyed by Latyl Blue 50 dye and per cent of dye on yarn at 15. 30 and 45 min. calculated from dye concentrations of samples of dye solutions drawn off at these times. Dye rate is given by the average ofthc following factors for the three time intervals:

Dye on Fiber X 100 V Time EXAMPLE VI A yarn of 1,800 deniercellulose acetate is bulked by the method of Example I under operating conditions as follows: steam temperature of 380 F. at 70 psig, yarn feed speed 700 ypm, overfeed 71 percent, and 30-mesh screen at speed of 40 ypm. A jet of the type shown in FIG. 4 was used. The resulting yarn showed 'high bulk I withtypical curvilinear, random-twisted crimp.

EXAMPLE VII A 200-denier yarn of a condensation polymer of metaphenylenediarninedsophthaloyl chloride is bulked by the process of Example I. Yarn is fed into the jet at 488 ypm withsteam at 650 F. temperature and 100 psig. Yarn coming from jet is impinged on a 30-mesh screen which is rotated at 55 ypm surface speed. Total yarn overfeed is 26 percent in this example and high-bulk yarnwith random twist and curvilinear crimp is. produced. The bulked yarn denier is 243 with a tenacity of 3.47 g/d, and elongation to break of 59 percent.

EXAMPLE vm Four ends of 250-denier, 50-filament zero twist yarn of poly(ethylene terephthalate) copolymer with 2 mol per cent of the sodium salt of poly(ethylene sulfisophthalate) are combined at a yarn guide and introduced EXAMPLE X A continuous filament yarn of 150denier, 40-

filament bright rayon having 2.5 tpi was bulked by the process of Example I using the jet of FIG.,4. Processing conditions include 500 F. steam at 40 psig, 470 ypm yarn feed speed, and 37 percent overfeed. The yarn impinges on a -mesh wire screen running at 52 ypm surface speed at point of yarn contact. Resulting yarn showed the random curvilinear crimp typical of prod ucts of this process. Yarn bulk was increased by about 50 percent.

, EXAMPLE XI One end of 1,000-denier, 64-f1lament polypropylene yarn is introduced into the jet using a process similar-to Example I. The feed speed is 165 ypm-with'65 percent overfeed and 340 F. steam at 90 psig. The yarn coming from jet is impinged on a stainless steel, 30-mesh wire belt running at 20 ypm surface speed at point of yarn contact. It has a cylinder bulk of 13.6 cm lgm; a denier as produced of 1,493, and a denier after boil-off of 1,713; and a crimp elongation as produced of 30.6 percent, and after boil-ofi of 54.1 percent. The resulting yarn shows a high level of curvilinear crimp typical of I yarns bulked by this technique.

simultaneously into a jet in an arrangement as shown in FIG. 1. Feed speed is 987 ypm, overfeed 74 percent, steam temperature 620" F. at 75 psig. Upon'emerging from the jet, the yarn is impinged on a 30-mesh wire screen running at 55 ypm.

The resulting yarn has a typical three-dimensional EXAMPLE [X A /1 cc spun yarn of 35 percent Egyptian cotton and percent staple fibers of poly(-ethylene terephthalate) with a breaking tenacity of 3.6 g/d, elongation to break of 20.2 percent, initial modulus of 48.2 g/d, and tenacity at 7 percent elongation of 1.8 g/d, was bulked by the process of Example I; Yarn feed speed is 500 ypm and steam temperature is 450 F. at 50 psig., Yarn emerging from the jet impinges on a 30-mes screen running at 55 ypm.

" A high degree of crimp is obtained together with an increase of 30 percent in dyeability.

curvilinear crimp and increased to about 1,750 denier.

' can be processed to give different visual properties.

EXAMPLE u This example is repeated with three yarns, respectively, one end of -l,OSO-denier, 68-filamenttrilobal poly(hexamethylene adipamide), and two ends of 1,000-denier, 70-filament trilobal polypropylene of melt index about 11. These are bulked with steam at 287 F. and 40 psig. with a yarn feed speed of ypm. and then impinged on a screen with a surface speed of 45 ypm.

The polypropylene components of the bulked yarn show a'random twist curvilinear'crimp whereas the nylon component bulked with a loopy yarn structure show a multiplicity of stable c'runodal loops of the character described in U.S. Pat. No. 2,783,609.

EXAMPLE XIII Ina process similar to Example I, a jet as disclosed in FIG. 1 of l-Iallc'len and Murenbeeld U.S. Pat. No. 3,005,251issued Oct. 24',v 1961, is used to impinge yarn on a slotted stainless steel drum (1 diameter). The surface speed of the drum is 40 ypm. Two-yam feed speed systems are used to meter a core yarn and an effect yarn to the bulking jet. The core yarn is 2l0-denier, l02-filament poly(hexamethylene adipamide) and is fed to the jet at 200 ypm. The effect yarn is 1,800 denier, 96-filament cellulose acetate at a feed rate of Y700 ypm. Steam temperature is 380 F. at 70 psig. The resultant core yarn is stable because of the nylon core and bulky because of the acetate effect yarn. This yarn has the characteristics and utility of a chenille yarn.

Interesting variations can be obtained by using the techniques disclosed in US Pat. No. 2,869,967, whereby some filaments can be broken or staple yarns and tactile EXAMPLE XIV One end of l ,080-denier, 68-filament yarn of poly(- hexamethylene adipamide) is prebulked by the method of Example I. This yarn is combined with two ends of 3,854,177 21 I 22 1,000-denier, 70-filament yarn of plypropylene as they through the jet, the yarn is impinged on a.30'-mesh wire are introduced into a jet andbulked by the methodof screen moving at 40 ypm.-The resulting bulked yarn Example I. The process uses saturated steam at 307 F., shows typical three-dimensional random curvilinear 60 psig, and the yarn feed speed is 140 ypm. The crimp, hasacylinder bulk of 10.0 cm /gm;anumber of blended yarns are impinged on a 30-mesh, stainless 5 crimps per inch as produced of 8.8 and after boil-off of steel screen with a surface speed of 70 ypm. 17.5; a bulk denier as produced of 5,174 and after boil- The yarns are blended and all of the component filaoff of 6,382; and a crimp elongation as produced of ments exhibit the typical random twist and curvilinear 46.5 percent and 76.2 percent after boil-off. The indicrimp. vidual fibers of this yarn are found to have undergone EXAMPLE V changes as shown by the data of Table VI. I

TABLE VI Three different yarns are bulked separately by the method of Example I, except that hot air is used as the B reaklng Elongatlon Modulus plasticizing fluid in place of superheated steam. The y p Tenacity (gpd) At Break m three yarns so bulked are (a) an 1,100-denier, bright, I high-tenacity yarn of poly(ethylene terephthalate), (b)

a 70-denier, SO-filament semidull trilobal yarn of a copolymer of poly(ethyleneterephthalate) with 2 mol per g cent of the sodium salt of poly(ethylene sulfisophtha- EXAMPLE late), and (c) a 160-denier, 13-filament trilobal semi- 0 A IOS-denier multifilament yarn of poly(ethylene Unbulked 2.2

Bulked dull yarn of poly(hexamethylene adipamide). Process- 2,6-naphthalate) is melt-spun and drawn 2.6X..lt has-a ing conditions are shown in Table IV. tenacity of 3.0 gpd and an elongation .of 23 percent.

333 ypm to a jet supplied with 5 36 F. steam at 54 psig. The yarn impinges on a screen surface, is removed TABLE IV Using the process of this invention, the yarn is fed at Yam a Yam b Yam C from the plasticizing stream in a tensionless state, Air Temperature "m 590 590 464 cooled to set the crimp and then wound up at a rate to Air Pressure (P 70 60 allow 28 percent overfeed. A highly-bulked yarn is ob- Yam Feed Speed (ypm) 387 800 301 yam o f d W0) 72 38 95 v talned which exhlblts a considerably increased dye rate Screen Type 30-me5h 30-melel:j so-melsh' 30 when compared to feed yarn. This yarn has a cylinder wire ename e ename ed a Semen Spced (ypm) 55 46 16 V bulk of 11.6 cm /gm., a bulk denier of 4,724 as pro duced and 6,966 after boil-off; and a crimp elongation of 28.8 percent as produced and 92.1 percent after In each case the yarn produced is a highly bulked boil-Offstructure with typical random-twisted, curvilinear- EXAMPLE XIX crimped individual filaments- A sheath core yarn prepared by the process of Exam- EXAMPLE XVI A continuous multifilament y of a copolymer of Example 1B of Table I. The differential shrinkage con- 35 "1 P Cent p y( t y t ep and 40 ditions of the two-component eccentric sheath core filmol per cent of poly(ethy n isophthalate) is treated aments accentuate the crimping effect of the subject which, in the lmbulked Condition, has defi e as pr process and result in an unusually high bulk, with the duced of 1,493 and after boil-off of 1,713; and a crimp fila ts crimped in the characteristic threeelongation as produced of 30.6 percent and a e bO ldimensional nonhelical random curvilinear configuraoff of 54.1 percent. It is bulked by the method of Examtion, The bulk is appreciably greater than would be ob- P ng Steam at 7 p g, s p t d 10 4750 a tained using normal fibers wherein the filaments are of the plasticizing fluid. The resulting yarn has a bulk dea single polymeric component.

nier as produced of 2,368 and after boil-off of 2,581;

a crimp elongation as produced of 57.9 and after boil- EXAMPLE XX off of 72.4; and a number of crimps per inch as pro- A variety of yarns are processed as shown in Table i duced of 8.4 and after boil-off of 8.6. It' shows the typi- VII, following the procedure of Example 1, unless othcal high-bulk configuration with filaments crimped erwise indicated. The poly(tetrachlorodiphenylolprowith characteristic three-dimensional, non-helical, ranpane isophthalate) of Item E was solventspun. The dom curvilinear configuration. The changes in fiber other yarns were prepared by the melt-'splnnlng and properties are illustrated in Table V. drawing conditions conventionally used for polyethyl- TABLE V I Sin gle-Fil. Tensile Props. [Boiled-Off) 7r Dye rea long. Modulus Item ln IO-Min. DPF .Tenacity (gpd) l) (gld) Unbulked 0.41 2.8 3.8 I 46 47 Bulked 1.21 3.7 3.1 102 28 EXAMPLE XVII I 5 ene terephthalate fibers. The principal process condiple l of US. Pat. No. 2,931,091 to A. L. Breen i's. crimped under the processing conditions described in tions and results are summarized in the-table. The.

A 38denier, 17-filament, continuous filament yarn treated yarn in all cases have a characteristic alternatof a polymer of poly(2,2-diphenylolpropane carboning S and Z twist. The filaments have random, persistate) is bulked by the method of Example I, using superant, three-dimensional, non-helical curvilinear crimp heated steam at 480 F. and 50 psig. After passing andare substantially free of crunodal loops.

mm A

m m w. A mm A @A m mp A mm A no m 2 A mm A 3 E Q AA A 5 MA mm A; ow AA MA @A vawm @2365 55 mm mm Q a ow Am 3 Q 9 mw 2-.. 523 aoswwcomo xflfim A m Ad A m A 3A m A @A AM m 9m iww S OES uw aoa :3 556 mm *m cm 3 mm ow S on 5 mm A523 dwpi o 9 3 NA 2 ow 0A 3 ow 2 2 5A? 63% 52am cm on mm on Am ow an em Am 3 m QQ 2583 Em m mm can now Q8 cam wow wow 69 0mm 0mm I. O o 53363 535 g 8o A mow A 80 A OS A 2m 8 A OS A c2 8o A 5 95 2; 88A uwcomfiunoo 93830.5 2 Q: E EA 8A NA Am ma .8 5 1.5.. wd J AGQE EEEH 3 mm mm 2 AA 3 E 3 mm mm 1 3523 As mwzo o v flm w m A A A m w m o m b A o A h m o m o m nawm 32289 9v A Qv 5 cofioww mmE Gm Qw Qw m m Qm m Cw Qm Qw 553 o o o o o NmA o o o o v on 1" Am on on A m on wm #m P o." omA E. on Am R 2. m2 m3 53m finasw A e E5 2839 age 555 c 55 0 50m cmipvam $555 0 555-2 F590? 775 935 2 E wow zwfiow A SE2 h H HA U A m D O m QEE 5P HAMIJH the results shown therein. Except as noted, the procedure is the same as in Example I.

2. A process as defined in claim 1 wherein fluid heated to at least 300 F. is jetted at a velocity of at least 1/2 sonic velocity to form the turbulent zone,'th'e multifilament yarn is fed into the turbulent zone at a TABLE Vlll TEXTURING CONDITIONS YARN CHARACTERISTICS STEAM SPEEDS (vDrn) I Yam Type and Temp Pressure Screen Feed/Bulked Bulked' Yarn Description Composition F. psrg Feed Screen Take-up Type nier ul (from microscopic exam.)

. A. 70-34-T62 tpi 475 50 I000 50 710 wire 71/101 3.8/7.5 Random fiber twist; random polyethylene disc curvilinear crimp; yarn terephthalate diam. increase about S/ 1 do. 3Z do. do. do. do. do. do. do. 73/100 4.5/7.5 Same except diam.chg.

V about 14/3. do. 72 do. do. do. do. do. do. do. 70/96 3.5/7.2 Same except diam.chg.

' about 3/1. do. 14Z do. do. do. 500 50 B.C.** do. 1 1/97 Random twist, curv.crimp; diam. increase /17; plus some random yarn twist.

B. 50/50 540 50 500 50 BC." do. 324/331 Random twist, curv. crimp polyacrylonitrile/wool in polyacrylonitrile fibers; 3 2 cc. diam. increase about 2/ 1.

C. 50/50 do. do. do. do. do. do. 406/530 Random twist, curv. crimp polyacrylonitrile/wool in polyacrylonitrile. Large 25/2 cc. bulk increase; diam. increase about 2/1.

D. 100% T42 do. I do. do. do. do. do. 576/888 Curv. crimp-,high bulk;

' polyacrylonitrile spun diam. increase about 2/1.

100% polyester i 1254/ Curv. crimp-high continuous filament 475 do. do. do. do. do. 1631 bulk; diam. increase about F. 100% polyacrylonitrile 540 do. do. do. do. do. 549/761 Diam. increase 2!] for spun bulked yarn; curv.crimp;

some fiber twist.

G. I Polyethylene 150 298 do. 1 65 25 98 wire 164/171 Curvilinear crimp.

denier l0 filament belt H. 70-50 cellulose 510 do. 534 49 474 wire 76/89 3/9 Typical S-dimensional triacetate disc curv.crimp; diam. incr.

about 9/2. Twist.

l. 4 ply/20/22 Silk 600 do. 390 360 do. 63/75 3.8/6.2 Random twist, curv.crlmp.

yarn diameter increase about 6/1.

'Bullt measured by standard cylinder bullt technique as described previously. "Bulk collection.

'"Copolyestcr from ethylene glycol and 85-90; \crephthalic acid and 15-107 isopl thalic acid.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the following claims.

We claim:

1. In a process for texturing multifilament yam'comprising thermoplastic synthetic linear polymer filaments with compressible fluid heated to a temperature which will plasticize the filaments to impart a persistent crimp having a random, three-dimensional, curvilinear, extensible configuration continuously along the filaments; the improvement which comprises jetting a high velocity stream of the heated fluid to form a' turbulent plasticizing zone of heated fluid, feeding the filaments at a rate of at least 500 yards per minute into the turbu lent zone, continuously forwarding and crimping the filaments by turbulent action of the heated fluid while the filaments are in a plasticized condition, receiving the treated filaments on a moving surface to remove the filaments from the heated fluid in a substantially tensionless state, conveying the filaments on the moving surface through a stream of cooling fluid to set the rate of at least 1,000 yards per minute fortreatrnent and the treated yarn is received on a moving screen and rapidly cooled'at low tension to form a crimped yarn having a final yarn denier (measured in relaxed form after hot-wet relaxation) at least 30 percent greater than the feed yarn denier.

3. A process as defined in claim 2 wherein a stream of cooling fluid is impinged on the moving screen and the filaments are conveyed through the impinging stream on the screen to set the crimp.

4. A process as defined in claim 2 wherein the feed yarn has'less than 1 turn per inch of twist.

5. A texturizing unit for the production of texturized yarn comprising a body, an air passageway extending through said body, air supply means communicating with said air passageway, yarn guiding nipple extending having, a yarn passageway extending longitudinally filaments from the moving surface.

therethrough, an outlet for said air passageway for exiting both yarn and air supplied to said unit, said outlet having a converging entrance from said air passageway,

the forward portion of said nipple extending into and terminating in said converging entrance, the forward portion of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance.

6. A nozzle for the production of texturized yarn comprising a body having an air chamber, a yarn guiding nipple having a yarn passageway extending longituward portion of said nipple extending into and terminating within said converging entrance, the forward portion of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance.

7. A nozzle for the production of texturized yarn comprising a main body having an air chamber, a yarn guiding nipple extending from the rear of. said body through said air chamber, said nipple having a yarn passageway extending longitudinally therethrough, an air supply passageway communicating with said air chamber, a common outlet for said air chamber for exiting both yarn and air supplied to said nozzle, said common outlet having a converging entrance extending to a most restricted portion, the forward portion of said nipple extending into and terminating within said converging entrance short of said most restricted portion, the forward portion of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance.

8. A nozzle for the production of texturized yarn recited in claim 7 wherein said yarn passageway is so aligned and dimensioned that the forward axial projection of said yarn passageway is wholly contained byvthe most restrictedv portion of said common outlet.

9. A nozzle for the production of texturized yarn comprising a body having an air chamber, said body 28 having a forward end and a rearward end, a yarn guiding nipple extending forward from the rearward end of' said body through said air chamber, said nipple having a yarn passageway extending longitudinally therethrough, an air supply passageway communicating with said air chamber, a common outlet at the forward end of said body for both yarn and air passed through said nozzle, said common outlet. having a converging entrance and a most restricted portion, said most restricted portion being forward of said converging entrance, the forward portion of said nipple extending at least into said converging entrance but not into said most restricted portion, the forward end of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance andflparallel thereto.

10. A nozzle for the production of texturized yarn comprising a body having an air chamber, said body having an inlet region and an outlet region, a yarn guiding'nipple extending forward from the inlet region of said body through said air chamber, said nipple having a yarn passageway extending longitudinally there through, an air supply passageway communicating with said air chamber, a venturi outlet portion at the outlet region of said body for both yarn and 'air' passed through said nozzle, said venturi outlet portion comprising a converging entrance from-said chamber leading to a most restricted portion and diverging exit, the forward end of said nipple extending at least into said converging entrance but not into said most restricted portion, the forward end of said nipple being laterally offset with respect to the longitudinal axis of said venturi outlet portion, the longitudinal axis of the yarn passageway of said nipple being laterally offset with respect to the longitudinal axis of said venturi outlet portion an amount equal to the lateral offset of said nipple. =l

Claims (10)

1. IN A PROCESS FOR TEXTURING MULTIFILAMENT YARN COMPRISING THERMOPLASTIC SYNTETIC LINEAR POLYMER FILAMENTS WITH COMPRESSIBLE FLUID HEATED TO A TEMPERATURE WHICH WILL PLASTICIZE THE FILAMENTS TO IMPART A PERSISTENT CRIMP HAVING A RANDOM, THREE-DIMENSIONAL, CURVILINEAR, EXTENSIBLE CONFIGURATION CONTINUOSULY ALONG THE FILAMENTS; THE IMPROVEMENT WHICH COMPRISES JETTING A HIGH VELOCITY STREAM OF THE HEATED FLUID TO FORM A TURBULENT PLASTICIZING ZONE OF HEAGTED FLUID, FEEDING THE FILAMENTS AT A RATE OF AT LEAST 500 YARDS PER MINUTE INTO THE TURBULENT ZONE, CONTINUOSULY FORWARDING AND CRIMPING THE FILAMENTS BY TURBULENT ACTION OF THE HEATED FLUID WHILE THE FILAMENTS ON A IN A PLASTICIZED CONDITION, RECEIVING THE TREATED FILAMENTS ON A MOVING SURFACE TO REMOVE THE FILAMENTS FROM THE HEATED FLUID IN A SUBSTANTIALLY TENSIONLESS STATE, COVEYING THE FILAMENTS ON THE MOVING SURFACE THROUGH A STREAM OF COOLING FLUID TO SET THE CRIMP IN THE FILAMENTS, AND FINALLY TAKING UP THE COOLED FILAMENTS FROM THE MOVING SURFACE.

2. A process as defined in claim 1 wherein fluid heated to at least 300* F. is jetted at a velocity of at least 1/2 sonic velocity to form the turbulent zone, the multifilament yarn is fed into the turbulent zone at a rate of at least 1,000 yards per minute for treatment and the treated yarn is received on a moving screen and rapidly cooled at low tension to form a crimped yarn having a final yarn denier (measured in relaxed form after hot-wet relaxation) at least 30 percent greater than the feed yarn denier.

3. A process as defined in claim 2 wherein a stream of cooling fluid is impinged on the moving screen and the filaments are conveyed through the impinging stream on the screen to set the crimp.

4. A process as defined in claim 2 wherein the feed yarn has less than 1 turn per inch of twist.

5. A texturizing unit for the production of texturized yarn comprising a body, an air passageway extending through said body, air supply means communicating with said air passageway, yarn guiding nipple extending forwardly into said air supply passageway, said nipple having a yarn passageway extending longitudinally therethrough, an outlet for said air passageway for exiting both yarn and air supplied to said unit, said outlet having a converging entrance from said air passageway, the forward portion of said nipple extending into and terminating in said converging entrance, the forward portion of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance.

6. A nozzle for the production of texturized yarn comprising a body having an air chamber, a yarn guiding nipple having a yarn passageway extending longitudinally therethrough, said nipple extending from the rear of said body through said air chamber, an air supply passageway communicating with said air chamber, an outlet for said air chamber for exiting both yarn and air supplied to said nozzle, said common outlet having a converging entrance from said air chamber, the forward portion of said nipple extending into and terminating within said converging entrance, the forward portion of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance.

7. A nozzle for the production of texturized yarn comprising a main body having an air chamber, a yarn guiding nipple extending from the rear of said body through said air chamber, said nipple having a yarn passageway extending longitudinally therethrough, an air supply passageway communicating with said air chamber, a common outlet for said air chamber for exiting both yarn and air supplied to said nozzle, said common outlet having a converging entrance extending to a most restricted portion, the forward portion of said nipple extending into and terminating within said converging entrance short of said most restricted portion, the forward portion of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance.

8. A nozzle for the production of texturized yarn recited in claim 7 wherein said yarn passageway is so aligned and dimensioned that the forward axial projection of said yarn passageway is wholly contained by the most restricted portion of said common outlet.

9. A nozzle for the production of texturized yarn comprising a body having an air chamber, said body having a forward end and a rearward end, a yarn guiding nipple extending forward from the rearward end of said body through said air chamber, said nipple having a yarn passageway extending longitudinally therethrough, an air supply passageway communicating with said air chamber, a common outlet at the forward end of said body for both yarn and air passed through said nozzle, said common outlet having a converging entrance and a most restricted portion, said most restricted portion being forward of said converging entrance, the forward portion of said nipple extending at least into said converging entrance but not into said most restricted portion, the forward end of said nipple being laterally offset with respect to the longitudinal axis of said converging entrance and parallel thereto.

10. A nozzle for the production of texturized yarn comprising a body having an air chamber, said body having an inlet region and an outlet region, a yarn guiding nipple extending forward from the inlet region of said body through said air chamber, said nipple having a yarn passageway extending longitudinally therethrough, an air supply passageway communicating with said air chamber, a venturi outlet portion at the outlet region of said body for both yarn and air passed through said nozzle, said venturi outlet portion comprising a converging entrance from said chamber leading to a most restricted portion and diverging exit, the forward end of said nipple extending at least into said converging entrance but not into said most restricted portion, the forward end of said nipple being laterally offset with respect to the longitudinal axis of said venturi outlet portion, the longitudinal axis of the yarn passageway of said nipple being laterally offset with respect to the longitudinal axis of said venturi outlet portion an amount equal to the lateral offset of said nipple.

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