Simultaneously crimping and commingling yarns
United States Patent [19] Butler et al.  
 [451 Apr. 1, 1975 SIMULTANEOUSLY CRIMPING AND COMMINGLING YARNS [75] Inventors: Russell H. Butler, Dover; l-lendrikus J. Oswald; Young D. Kwon, both of Morristown, all of NJ.  
 [73] Assignee: Allied Chemical Corporation, New  
 York, NY.  
 [22] Filed: Mar. 8, 1974 [21] Appl. No.: 449,427  
 Primary Examiner-Louis K. Rimrodt Attorney, Agent, or FirmArthur J. Plantamura; Jack B. Murray, Jr.  
 YARN FEED \l\ [57] ABSTRACT Apparatus and process for simultaneous crimping and commingling of continuous filament yarns are provided. The yarn is introduced as feed into a fluid contact chamber in which the yarn is contacted with a heated fluid, such as steam, substantially coaxially to the longitudinal axis of the fluid contact chamber. The yarn is then directed under the force of the heated fluid through a first energy tube wherein the yarn absorbs a portion of the heat of the fluid, and is then passed into an expansion chamber wherein the yarn impacts upon a portion of the interior surface of the chamber. The impacted yarn is then passed into a second energy tube wherein the yarn absorbs additional heat, and thence into a stuffer tube wherein the flow of yarn is impeded, thereby establishing a yarn plug from which crimped and commingled yarn is subsequently removed. In a second embodiment, the expansion chamber and second energy tube are positioned such that the yarn impacts upon an interior surface of the second energy tube.  
 8 Claims, 7 Drawing Figures PATENTEUAPR 1197s 3.874.045 saw 2 BF 2 FIG. 7  
 FIG. 5  
 FIG. 6  
 SIMULTANEOUSLY CRIMPING AND COMMINGLING YARNS CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to commonly owned, 00- filed application, APPARATUS AND PROCESS FOR SIMULTANEOUS CRIMPING AND COMMIN- GLING OF YARNS, Ser. No. 449,409, filed Mar. 8, 1974 (filed by Y. D. Kwon; Russell H. Butler, H. J. Oswald and D. W. Kim).  
 BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to process and apparatus for simultaneous crimping and commingling of continuous filament yarns.  
 2. DESCRIPTION OF THE PRIOR ART Synthetic fiber yarn to be employed in fabric, such as in carpets and wearing apparel, is frequently subjected to a crimping process to generate curvilinear twists in the yarn so as to impart elastic stretch and bulk to the yarn. Such yarn is also subjected to a commingling process whereby entanglements are inserted between adjacent yarn filaments to enhance cohesiveness between these filaments. In addition, commingling helps to prevent stray filaments from snagging machine guides during subsequent processing and to prevent the separation of individual yarn ends in jet texturizing processes which require more than one yarn end per jet.  
  In conventional process, the crimping and commingling functions are carried out separately in different steps. Such a division of functions increases process costs and generates increased equipment requirements. Previous attempts to simultaneously crimp and commingle yarn have been unsuccessful in imparting the desired crimp and commingling properties. Typical dual-function apparatus are those disclosed in US. Pat. No. 3,303,546 (issued in 1967 to Van Blerk), US. Pat. No. 3,409,956 (issued in 1968 to Longbottom et al.) and East German Pat. No. 17,786 (issued in 1960 to Bruetting) wherein yarn is contacted with a steam jet positioned coaxially with respect to the yarn passage axis and US. Pat. No. 3,611,698 (issued in 1971 to Horn) wherein pairs of facing steam jets impact on a common plane at an angle perpendicular to the yarn passage axis. In the apparatus of US. Pat. No. 3,409,956, and East German Pat. No. 17,786 coaxial contact of the yarn with steam has the disadvantage of failing to impart any significant amount of commingling to the yarn. In the apparatus of US. Pat. No. 3,61 1,698 the steam jets do not impart any portion of their force in the direction of the yarn travel through the apparatus, thereby necessitating the use of a mechanical pulling device to cause the yarn to pass through the apparatus. The use of such mechanical pulling for this purpose is not desirable because it tends to destroy any crimp that has been previously imparted to the yarn.  
  However, most significantly, these prior art apparatus for simultaneous crimping and commingling of yarn have failed to provide the levels of crimp and commingling previously achieved when these functions were carried out in separate steps. Thus, the dual-function apparatus failed to simultaneously perform commingling and crimping functions while maintaining the desired levels of crimping and commingling which separate-function apparatus had previously achieved.  
 SUMMARY OF THE INVENTION In accordance with the present invention, there are provided apparatus and process for simultaneously crimpingand commingling continuous filament yarn. The apparatus of the present invention comprises: a fluid contact chamber; yarn feed means for feeding yarn into said fluid contact chamber; heated fluid supply means for introducing heated fluid into said fluid contact chamber substantially along the longitudinal axis of said chamber; a first energy tube wherein said yarn absorbs heat from said heated fluid, said first energy being positioned about a longitudinal axis and communicating with said contact chamber for yarn passage therethrough, an expansion chamber having a cross-sectional area at its interface with said first energy tube which is larger than the cross-sectional area of said first energy tube, said expansion chamber being positioned such that said longitudinal axis of said first energy tube intersects an impacting surface in said expansion chamber; a second energy tube wherein said yarn absorbs additional heat from said heated fluid; and a stuffer tube for texturizing said yarn; said expansion chamber, said second energy tube and said stuffer tube communicating successively with said first energy tube for yarn passage therethrough. In a second embodiment of the apparatus of the present invention, said expansion chamber and said second energy tube are positioned such that the longitudinal axis of said first energy tube intersects an impacting surface in said second energy tube.  
  The process of the present invention comprises: passing yarn into a fluid contact zone; contacting said yarn in said fluid contact zone with heated fluid introduced into said zone substantially coaxially to the longitudinal axis of said zone; passing said yarn and said heated fluid into a first heat absorbing zone wherein said yarn absorbs heat from said heated fluid; directing the yarn under the influence of said heated fluid into an expansion zone having a cross-sectional area at its interface with said first heat absorbing zone which is larger than the cross-sectional area of said first heat absorbing zone, said expansion zone being positioned such that yarn passing from said first heat absorbing zone impacts upon an impacting surface in said expansion zone; passing the yarn and said heated fluid from said expansion zone into a second heat, absorbing zone, wherein the yarn absorbs additional heat from said heated fluid; passing the yarn and heated fluid from said second heat absorbing zone into a texturizing zone, wherein the flow of yarn is impeded, thereby establishing a yarn plug; exhausting heated fluid from said texturizing zone; and removing crimped and commingled yarn from said yarn plug. In a second embodiment of the process of the present invention, said expansion zone and said second heat absorbing zone are positioned such that yarn passing from said first heat absorbing zone impacts upon an impacting surface in said second heat absorbing zone.  
  It has been found that the present invention enables simultaneous achievement of levels of crimp which are comparable to, and levels of commingling which are superior than, the levels which result from conventional processes in which crimping and commingling steps are sequentially performed. In addition, the process and apparatus of the present invention have the advantage of imparting such improved crimp and commingling properties in a single apparatus, thereby decreasing equipment requirements and reducing processing costs by as much as 50 percent. Furthermore, the substantially coaxial introduction of heated fluid into the apparatus of the present invention enables easier starting of the apparatus and greatly aids in forcing the yarn through the apparatus, thereby decreasing the necessity for mechanically pulling the yarn therethrough.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-sectional view of the apparatus of the present invention.  
  FIGS. 2, 3 and 4 are cross-sectional views of first energy tube, expansion chamber and second energy tube of apparatus of the present invention.  
  FIG. 5 is a diagrammatic illustration of a typical process employing the apparatus of the present invention.  
  FIG. 6 is an illustration of the vibration of yarn in the energy tube of the prior art apparatus of US. Pat. No. 3,409,956.  
  FIG. 7 is an illustration of the vibration of yarn in the second energy tube of the present invention.  
 DETAILED DESCRIPTION OF THE INVENTION As indicated above, the process and apparatus of the present invention allow the simultaneous crimping and commingling of continuous filament yarn. In the apparatus of the present invention, the yarn is contacted in a fluid contact chamber with heated fluid, e.g. steam, supplied through a nozzle by a pressurized source, substantially coaxially to the longitudinal axis of the zone, thereby causing the yarn to pass into and through a first energy tube wherein the yarn absorbs at least a portion of the heat from the heated fluid. The yarn then passes into a portion of the apparatus, i.e. the expansion chamber and the second energy tube, wherein the yarn impacts upon an impacting surface.  
  The term impacting surface&#34; is herein meant to define that portion of the interior walls of the yarn passages of the present invention upon which the yarn first impacts after passing out of the first energy tube. In the preferred embodiment the impacting surface comprises the chamber wall which define the expansion zone. However, the impacting surface may also comprise the inner wall of the second energy tube.  
  The heated fluid used to treat continuous filament yarns in the present invention may be air, steam or any other compressible fluid or vapor capable of plasticizing action on the yarn. Hot air will give sufficient plasticization in the expansion zone for many fibers although it may be desirable for certain fibers to supplement the temperature effect with an auxiliary plasticizing medium. 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 temperatures do not reach the melting point of the fiber. However, with fibers made from fusible polymers, the most effective bulking and the greatest productivity are obtained when the temperature of the heated fluid in the impacting zone is above the melting point of the fiber. In this case, the yarn speed should be great enough so that melting does not occur. In a preferred embodiment, the yarn to be crimped and commingled is contacted in the fluid contact zone with steam supplied at a temperature within the range of about 150 to 500C. and preferably 200 to 450C. and at a pressure of from about 5 to 200 psig. and preferably 5 to psig.  
  The velocity at which the heatd fluid is passed through apparatus 10 is not critical, and the process of the present invention may employ any heated fluid velocity which is sufficient to carry the yarn longitudinally through the passages 14, 18, 24 and 26 and into passage 28. However, heated fluid velocity of less than sonic velocity is preferred.  
  With reference to the drawings wherein like numerals refer to the same or similar element, in FIG. 1 the apparatus of the present invention is indicated generally at 10 and includes: yarn contact chamber 11 defining fluid contact zone 21; feeder tube 22; nozzle 12; first energy tube 13 defining first energy tube passage 14; offset expansion chamber 17 defining expansion zone 18; second energy tube 23 defining passage 24; and stuffer tube 27 defining texturizing passage 28 and provided with fluid escape vents 29.  
  Nozzle 12, which comprises the heated fluid supply means in FIG. 1, is positioned so as to emit heated fluid into fluid contact zone 21 substantially along longitudinal axis 16 of zone 21 in the direction of yarn travel through apparatus 10.  
  Feeder tube 22, which comprises the yarn feed means in FIG. 1, is housed in fluid contact chamber 11 to communicate fluid contact zone 21 with a yarn feed source (not shown) for passage of yarn into apparatus 10 for treatment. Fluid contact zone 21 preferably converges in the direction of yarn passage through apparatus 10 to aid in passing yarn and heated fluid from zone 21 into first energy tube passage 14. Zone 21 is defined by surface 41 which may be either flat or curved and, thus, zone 21 may be of various geometric shapes, such as for example conical, semi-spherical, hyperbolic and parabolic.  
  First energy tube 13 is positioned about axis 16 and communicates with fluid contact zone 21 to provide for yarn passage therethrough. While preheating of first energy tube 13 is not required, tube 13 may be heated to a temperature of from about 40 to 300C. by a suit able external heating means, as for example, steam heating coils 42, so as to further heat yarn passing therethrough and to increase the levels of crimp imparted therein. So as to provide for increased ease of passage of yarn into expansion chamber 17, the longitudinal axis of first energy tube passage 14 in the preferred embodiment coincides with longitudinal axis 16 of zone 21, and the inside diameter of passage 14 substantially corresponds to the diameter of the opening formed by surface 41 at the interface between zone 21 and passage 14.  
  Expansion chamber 17, which converges in the direction of yarn passage therethrough, communicates successively with first energy tube passage 14 and second energy tube passage 24 and has a cross-sectional area at its interface with first energy tube 13 which is larger than the cross-sectional area of first energy tube 13. Expansion zone 18, which may be symmetrical or assymmetrical, is defined by expansion chamber wall 19, which may be either flat or curved. Where zone 18 is symmetric, the axis of symmetry of zone 18 preferably corresponds to longitudinal axis 20 of second energy tube 23, as shown in FIGS. 1, 2, 3 and 4. Symmetrical geometrical shapes which zone 18 may have are, for example, semi-spherical, parabolic, conical, hyperbolic and elliptical, with the conical and parabolic shapes being preferred.  
  Expansion chamber 17 is preferably positioned so as to cause the longitudinal axis of first energy tube 13 to intersect expansion chamber wall 19. In operation of the preferred embodiment, therefore, yarn passing from first energy tube 13 impacts upon an impacting surface in expansion chamber 17, i.e. wall 19. FIGS. 1, 2 and 3 illustrate such an arrangement of chamber 17 and tubes 13 and 23. According to a second embodiment, expansion chamber 17 and second energy tube 23 are positioned so as to cause longitudinal axis 16 of first energy tube 13 to intersect inner surface 23a of second energy tube 23. In operation of an apparatus having such a configuation, yarn passing from first energy tube 13 first impacts upon an impacting surface in second energy tube 23, i.e. surface 23a. FIG. 4 illustrates such an arrangement of chamber 17 and tubes 13 and 23.  
  Where expansion zone 18 is symmetric, the interrelationships discussed above between zone 18 and tubes 13 and 23 may be further defined with reference to longitudinal axis 16 of first energy tube 13 and the axis of symmetry of zone 18. The axis of symmetry, i.e. axis 20 in FIGS. 1, 2, 3 and 4, may be offset from longi tudinal axis 16 by either a pure rotation, a parallel translation or both a rotation and translation. Where, as illustrated in FIG. 1, axis 20 is offset from axis 16 by a parallel translation, axis 20 is parallel to axis 16. Where axis 20, as in FIG. 2, is offset from axis 16 by a pure rotation, axis 20 intersects axis 16 at the interface, designated 43, between passage 14 and zone 18. The rotation offset angle, indicated as A in FIG. 2, is defined as the minimum angle formed by the intersection of axes 20 and 16 when said axes are offset by a pure rotation and is generally from about 90 to less than about 180, and preferably from about 135 to less than about 180.  
  Alternatively, axis 20 may be offset from axis 16 by both a rotation and translation. Such a configuration occurs, as illustrated in FIGS. 3 and 4, when axis 20 and 16: (l do not intersect at the interface, designated 43, between passage 14 and zone 18; and (2) are not parallel. In such a configuration angle B is defined in that view of apparatus in which the angle is a maximum and is generally from about 90 to less than about 180, and preferably from about 135 to less than about 180.  
  It will be apparent to one skilled in the art that configurations other than those shown in FIGS. 1, 2, 3 and 4 may be employed in which expansion chamber 17 and second energy tube 23 are positioned such that longitudinal axis 16 of tube 13 intersects an impacting surface, as that term is herein defined.  
  Second energy tube 23 is positioned about axis 20 and communicates successively with expansion chamber 17 and stuffer tube 27 for yarn passage therethrough. While not required, as with tube 13, tube 23 may be heated to a temperature of from about 40 to 300C. by a suitable external heating means, as for example, steam heating coils 44, so as to further heat yarn passing therethrough and to increase the levels of crimp imparted therein. Second energy tube 23 defines, at the discharge end thereof, passage 26 which may be of a uniform cross-section or, as is preferred,  
 which diverges in the&#39;direction of yarn passage therethrough. Inner surface 26a of passage 26 may be either flat or curved, thereby defining passage 26 to be of various geometric shapes, such as for example, cylindrical, semi-spherical, parabolic, conical, hyperbolic and elliptical, with the conical and parabolic forms being preferred. Where passage 26 is conical, as illustrated in FIG. 1, conical angle C is defined and is generally less than about and preferably less than about 45. Particularly outstanding results are obtained when conical angle C is from about 10 to 20. Where passage 26 is cylindrical in shape, passage 26 preferably is of a diameter which corresponds to the inside diameter of second energy tube 23. A fluid exit plate 46 is located at the discharge end of passage 26 and is provided with slots, holes or a combination of both to allow heated fluid and yarn to pass therethrough. The construction of such a plate is well known and is described, for example, in U.S. Pat. No. 3,409,956.  
  Stuffer tube 27 defines texturizing passage 28 disposed about axis 20 and is adapted to contain a compacted yarn mass, designated as yarn plug 31 in FIG. 4. Stuffer tube 27 is provided with a plurality of escape vents 29, illustrated in FIG. 1 as being positioned concentric to axis 20, which communicate texturizing passage 28 with the atmosphere to allow escape of heated fluid from passage 28. While such arrangement is not critical, in the preferred embodiment the longitudinal axis of texturizing passage 28 coincides with axis 20, and vents 29 are disposed so as to cause the exiting heated fluid to be released from passage 28 in a direction substantially opposite to the yarn path travel through apparatus 10 and parallel to axis 20. The term substantially opposite as used herein includes heated fluid discharged from texturizing zone 28 at an angle of to measured on the basis of axis 20 and countercurrent to yarn path travel. While such a concentric arrangement of fluid escape vents is preferred, it is not intended to be limiting. Thus, stuffer tube 27 may be provided with aperatures (not shown) located along the length of passage 28 which are adapted to permit the escape of fluid therefrom. Alternatively, stuffer tube 27 may be constructed of a gas permeable material such as a steel mesh screen or micro-porous steel to allow escape of heated fluid from passage 28. While not critical to the present invention, texturizing passage 28 may have a larger diameter than the maximum diameter of diverging passage 26 so as to form an annulus between the inner periphery of texturizing passage 28 and the outer periphery of passage 26.  
  In the preferred embodiment, fluid contact zone 21 and first energy tube passage 14 are disposed concentric to longitudinal axis 16, and expansion zone 18, second energy tube passage 24, passage 26 and texturizing passage 28 are each disposed concentric to axis 20.  
  Referring now to FIG. 5, wherein a process employing the apparatus of the present invention is illustrated, continuous filament yarn is unwound from yarn supply spool 33 and passed to feeder and draw rolls 34, 35 and 36 and is then passed to apparatus 10 wherein the yarn is treated and forms yarn plug 31 as described previously. Crimped and commingled yarn 32 is then removed from apparatus 10 by end rolls 38 and 39 and is then wound on winding roll 40.  
  In operation of the apparatus of FIG. 1, continuous filament yarn is fed through feeder tube 22 into fluid contact chamber 11 into which heated fluid such as steam is introduced through coaxial nozzle 12, thereby causing the contacted yarn to pass into first energy tube passage 14, wherein the yarn absorbs at least a portion of the heat from the heated fluid. As discussed above, alternate external heating sources 42 may be applied to first energy tube 13, thereby further heating the yarn passing through zone 14. The yarn which, depending on the conditions of operation, e.g. the type of yarn, the temperature and pressure employed, is reduced to a semi-plastic state, is then aspirated under the influence of the heated fluid into expansion zone 18 of offset expansion chamber 17 wherein the yarn preferably impacts upon a portion of expansion chamber wall 19. The impacted yarn is then passed under the influence of heated fluid into second energy tube 23, which may also be provided with external heating coils 44 wherein the yarn absorbs additional heat from the heated fluid, and is then passed into texturizing passage 28 wherein the flow of yarn is impeded, thereby establishing a yarn plug as in conventional stuffer tube 27, such as is described in U.S. Pat. No. 3,409,956. From texturizing zone 28 which may be operated at a reduced pressure of from about to psig., heated fluid exits via fluid escape vents 29 located concentric to axis 20. Crimped and commingled yarn is preferably removed from stuffer tube 27 at a linear speed which is slower than the linear speed at which yarn is fed to texturizing passage 28, so as to maintain the yarn plug therein.  
 By aspirating the yarn into expansion zone 18 under the influence of the heated fluid, the yarn bundle is caused to expand, thereby effecting increased commingling of adjacent yarn filaments. Furthermore, by impacting the yarn upon an impacting surface of the present invention a certain amount of twist is imparted to the yarn, thereby further increasing the commingling of adjacent yarn filaments. The yarn which is thus impacted is caused to vibrate within second energy tube passage 24 in an unconventional manner which is believed to&#39; further contribute to the crimp and commingling levels achieved. FIG. 6 illustrates vibration patterns in yarn 62 contacted in the apparatus of U.S. Pat. No. 3,409,956. As may be seen, this vibration pattern is substantially sinusoidal. FIG. 7 illustrates the substantially non-sinusoidal vibration which the yarn undergoes in second energy tube passage 24 (i.e. the second heat absorbing zone) in the apparatus of the present invention. As may be seen from FIG. 7, adjacent yarn filaments are caused by the vibration to form a folded-wave pattern, the folds of which are exemplified by 60 and 61. This folded-wave pattern is believed to enhance the crimp and commingling properties of the yarn.  
  The process and apparatus of this invention can be used to simultaneously crimp and commingle any natural or synthetic plasticizable filamentary material. Thermal plastic material such as polyamides, e.g poly (epsilon caproamide), poly (hexamethylene adipamide); cellulose esters; polyesters, e.g. polyethylene terephthalate, poly (hexahydro-p-xylene terephthalate), etc., and polyolefins and polyacrylics, e.g. polyethylene and polyacrylonitrile as well as copolymers thereof, can be treated by the process and apparatus of the present invention.  
  In addition, both monofilaments and yarns of textile deniers, as well as heavy carpet and industrial yarns (either singly or combined in the form of a heavy tow) may be treated by the present invention. When the yarn to be treated is composed of filaments which are made from synthetic materials, a filament of any crosssection type may be treated. Cruciform, Y-shaped, delta-shaped, ribbon, and dumbbell and other filamentary cross-sections can be procesed at least as well as round filaments and usually contribute still higher levels of crimp and commingling than is obtained with round filaments.  
  The process and apparatus of the present invention may be further illustrated by reference to the following examples. In the examples the term crimp bends per inch is determined by examining a length of yarn under a microscope and counting the number of filament bendings for 1 inch of stretched length. The term entanglements per meter&#34; (E.P.M.) is determined by passing the yarn through a conventional testing device in which a needle is inserted between filaments. Each time the needle is pushed in the direction of yarn motion by a local entanglement, a counter in the device is activated to count the number of entanglements per meter of the stretched length of the yarn. The term crimp elongation after boil (C.E.A.B.) is determined by measuring the length of a sample of crimped yarn at a tensile stress level of 0.002 gram per denier. The yarn is then boiled in water for 30 minutes at a pressure of 1 atmosphere and then dried at a temperature of 150C. for 10 minutes and then conditioned for a period of 2 hours at a temperature of 23C. and a relative humidity of 65 percent. The length of the conditioned yarn is then determined at a tensile stress level of 0.5 gram per denier. The value thereby obtained is compared to the length of the unboiled yarn obtained at a tensile stress level of 0.002 gram per denier and the percent elongation calculated.  
 EXAMPLE 1 Referring to FIGS. 1 and 5, an undrawn, continuousfilament, 3,300 denier nylon 6 yarn is fed to a series of 3 feed rolls. Feed roll 2 is maintained at a temperature of 100 and feed roll 3 is maintained at a temperature of 180. The draw ratio between feed rolls 1 and 2 is 1.1 and between feed rolls 3 and 1 is 3.l. Roll 3 is operated at a linear speed of 5,000 ft. per minute. From feed roll 3 the yarn is passed through an apparatus of the present invention, wherein the yarn is treated as described be low. The treated yarn is removed from the texturizing zone of the apparatus at a rate of 3,300 ft. per minute by end rolls 4 and 5, the draw ratio between end rolls 5 and 4 being set at 1.03. A draw ratio between end roll and feed roll 3 is maintained at 0.66. From end roll 5 the yarn is taken up by a Leesona 959 High Speed winder at a tension of grams.  
  The yarn is contacted in the fluid contact zone with steam at a temperature of 300C. and a pressure of psig. supplied to the fluid contact zone through nozzle positioned coaxially to the longitudinal axis of the fluid contact zone and having an inside diameter of 0.083 inch. The yarn and steam are then passed under the influence of the steam into the first energy tube passage positioned concentric to the above contact zone axis and having an inside diameter of 0.145 inch and a length of 6.5 inches, in which the yarn is heated to about C. The heated yarn is then directed under the influence of the steam into the expansion chamber which defines a conical expansion zone wherein the yarn impacts uppon a portion of expansion chamber wall. The expansion zone forms a conical angle of 16 and is positioned abut an axis of symmetry which is offset from the longitudinal axis of the first energy tube passage by a 0.2 inch parallel translation. The expansion zone has a minimum inside diameter at the interface with the second energy tube passage of 0.16 inch and a maximum inside diameter at the entry end of said expansion zone of 0.5 inch.  
  The impacted yarn is then passed into the second energy tube passage having an inside diameter of 0.16 inch and a length of 1.9 inches, wherein the yarn absorbs additional heat from the steam. The yarn is then passed through a conical, diverging passage which has a conical angle of 17, and which expands to a diameter of 0.3 1 inch over a distance of 0.5 inch measured longitudinally along the longitudinal axis of the second energy tube. The yarn is then aspirated into a texturizing passage having an inside diameter of 0.54 inch and a length of 9 inches, wherein the flow of yarn is impeded thereby establishing a yarn plug. The stuffer tube is provided with 12 fluid exhaust vents having a diameter of 0.094 inch which are spaced symmetrically in an annular ring to discharge fluid from the texturizing pas sage in a direction substantially opposite to the direction of yarn travel through the texturizing passage.  
  The yarn treated by the above process is determined to have 25 entanglements per meter, a crimp elongation after boil of about 28 percent, a texture energy of 0.8 X and 28 crimp bends per inch.  
 EXAMPLE 2 Under the identical process conditions of Example 1, undrawn 3,300 denier nylon 6 yarn is passed through an apparatus having a conically shaped expansion zone which has a conical angle of 30 and which has a minimum inside diameter of 0.16 inch and a maximum inside diameter of 0.5 inch. All other apparatus dimensions are identical to those employed in the apparatus of Example 1.  
  Under the above operating conditions, the treated yarn is determined to have about 42 entanglements per meter, a crimp elongation after boil of 30 percent, a texture energy of 0.8 X 10*, and 29 crimp bends per inch.  
 EXAMPLE 3 Under the identical process conditions of Example 1, undrawn 3,300 denier nylon 6 yarn is passed through an apparatus having a conically shaped expansion zone which has a conical angle of 42 and which has a minimum inside diameter of 0.16 inch and a maximum inside diameter of 0.5 inch. All other apparatus dimensions are identical to those employed in the apparatus of Example 1.  
  The yarn treated under the above conditions is determined to have 46 entanglements per meter, a crimp elongation after boil of 29 percent, a texture energy of 0.8 X 10&#34;, and 31 crimp bends per inch.  
  Although certain preferred embodiments of the invention have been disclosed for the purpose of illustration, it will be evident to one skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention.  
 We claim:  
  1. A process for simultaneously crimping and commingling yarn which comprises:  
 a. passing yarn into a fluid contact zone;  
 b. contacting said yarn in said fluid contact zone with a heated fluid introduced into said zone substantially coaxially to the longitudinal axis of said zone;  
 0. passing said yarn and said heated fluid into a first heat absorbing zone, wherein said yarn absorbs heat from said heated fluid;  
 d. directing the yarn under the influence of said heated fluid into an expansion zone having a crosssectional area at its interface with said first heat absorbing zone larger than the cross-sectional area of said first heat absorbing zone;  
 e. passing the yarn and said heated fluid from said expansion zone into a second heat absorbing zone, wherein the yarn absorbs additional heat from said heated fluid;  
 f. said expansion zone and said second heat absorbing zone being positioned such that yarn passing from said first heat absorbing zone impacts upon an impacting surface;  
 g. passing the yarn and heated fluid from said second heat absorbing zone into a texturizing zone, wherein the flow of yarn is impeded, thereby establishing a yarn plug; and  
 h. removing crimped and commingled yarn yarn plug.  
 2. The process according to claim 1 wherein said heated fluid is steam.  
 3. The process according to claim 1 wherein said impact surface is in said expansion zone.  
 4. The process according to claim 1 wherein said impact surface is in said second heat absorbing zone.  
 5. An apparatus for simultaneously crimping and commingling yarn which comprises:  
 a. a fluid contact chamber;  
 b. yarn feed means for feeding yarn into said fluid contact chamber;  
 c. heated fluid supply means for introducing heated fluid to said fluid contact chamber substantially along the longitudinal axis of said chamber;  
 (1. a first energy tube wherein said yarn absorbs heat from said heated fluid, said first energy tube being positioned about a longitudinal axis and communieating with said contact chamber for yarn passage therethrough;  
 e. an expansion chamber having a cross-sectional area at its interface with said first energy tube which is larger than the cross-sectional area of said first energy tube;  
 f. a second energy tube wherein said yarn absorbs additional heat from said heated fluid;  
 g. said expansion chamber and said second energy tube being positioned such that said longitudinal axis of said first energy tube intersects an impacting surface;  
 h. said chamber communicating successively with said first energy tube and said second energy tube for yarn passage therethrough; and  
 i. a stuffer tube for texturizing said yarn communicating with said second energy tube for yarn passage therethrough.  
 6. An apparatus according to claim 5 wherein said impacting surface is in said expansion chamber.  
 7. An apparatus according to claim 5 wherein said impacting surface is in said second energy tube.  
 8. An apparatus according to claim 5 wherein a diverging passage is defined at the discharge end of said second energy tube.  
 from said