Field of Search:
28/1.6,1.4,1.7,1.3,72.14,72.11,72.12
Claims:
What is claimed is
1. Apparatus for texturing yarn comprising:
2. The apparatus of claim 1 wherein said stacked members comprise balls.
3. The apparatus of claim 2 wherein said balls include balls of different sizes.
4. The apparatus of claim 1 wherein the inlet of said second chamber is of substantially greater cross-sectional area than the outlet of said second chamber, and said retaining member extends between said inlet and said outlet.
5. The apparatus of claim 4 wherein the inlet and the outlet of said second chamber are of generally circular configuration.
6. The apparatus of claim 1, further comprising textured yarn takeup means spaced from the outlet of said second chamber to remove textured yarn from a wad of yarn broken up in said second chamber.
7. The apparatus of claim 1 wherein said first passage is cylindrical and said second passage is of truncated conical configuration.
8. The apparatus of claim 1, further comprising means forming a third passage spaced from the inlet of said first passage so that yarn directed through said third passage enters the inlet of said first passage, and said conduit means communicates with a region exterior of said third passage so that fluid introduced through said conduit means passes in heat exchange relationship with said third passage prior to being introduced into said first passage.
9. The apparatus of claim 1, further comprising a vent communicating with said first chamber to remove condensate formed within said first chamber.
10. The apparatus of claim 1 wherein the retaining member is a knitted fabric.
Description:
Synthetic fibers are commonly produced by extruding molten polymer through a spinneret. In order to produce yarns which have properties approximating those of wool or other natural materials, it is common practice to subject the extrudate from the spinneret to a texturing process. This can be accomplished by a variety of procedures known in the art, such as stuffer-box crimping, false twisting, and fluid jet texturing. One particularly effective procedure involves contacting the fiber with a high velocity fluid stream in a turbulent zone at an elevated temperature. The turbulence imparted to the fiber produces crimps which give the fiber a textured appearance. While such a procedure is effective in imparting crimp to the fiber, problems are often encountered in removing the material from the turbulent zone and removing the fluid from the textured fiber. Although various types of removal equipment are known, a need still exists for a more efficient method of removing yarn from a fluid texturing zone.
In accordance with this invention, the textured yarn from a fluid crimping zone is passed through an elongated first chamber which contains a plurality of discrete members, such as balls. The textured yarn forms an elongated wad of yarn which is surrounded by the stacked members. These members exert a force on the sides of the wad to confine the wad in a generally cylindrical or oval configuration. The fluid introduced into the turbulent zone is permitted to escape through the voids between the individual members. The wad is then passed through a second chamber which contains stacked members and a flexible tapered retaining member to facilitate the breaking up of the yarn wad. The resulting textured yarn can easily be removed as it emerges from the second chamber.
In the accompanying drawing,
FIG. 1 illustrates an embodiment of the apparatus of this invention which is employed to texture yarn.
FIG. 2 is a detailed view, shown partially in section, of a portion of the apparatus of FIG. 1.
Referring now to the drawing in detail and to FIG. 1 in particular, there is shown fluid texturing apparatus generally designated by reference numeral 10. This apparatus comprises an elongated sleeve 11 which has a hollow needle 12 positioned in the inlet section thereof. An elongated plug 14 is disposed in the outlet section of sleeve 11. Plug 14 has a central opening 14b therethrough. The inlet of opening 14b is tapered to provide a seat 14a adjacent the tip of needle 12. The outlet of central opening 14b constitutes a flared section 14c of increasing diameter. A conduit 17 communicates with sleeve 11 adjacent needle 12 to introduce a fluid, such as steam or air, at an elevated temperature.
A hollow chamber 18 having an inlet tube 18a is mounted immediately above sleeve 11 to receive yarn which is crimped in apparatus 10. A large number of relatively small balls 19a and 19b are disposed within chamber 18. Chamber 18 can be provided with an outlet conduit 21 which is connected to a drain or to a source of reduced pressure, not shown. A screen 21a is positioned across conduit 21 to retain balls 19a and 19b within chamber 18. A second chamber 22, which is illustrated in detail in FIG. 2, is positioned above chamber 18 by support rods 30. Chamber 22 is formed by first and second plates 23 and 24 which have respective central openings 23a and 24a therein. Plates 23 and 24 are held together in spaced relationship by a plurality of rods 25. An inner flexible tapered sleeve 26 is secured to the two plates and extends between the openings therein. An outer sleeve 27 extends between the outer edges of the two plates. Balls 28a and 28b, which correspond to respective balls 19a and 19b, fill the space between sleeves 26 and 27.
In the operation of the illustrated apparatus, one or more filaments 20a are inserted through needle 12 into the central passage of plug 14. These filaments can be delivered to the apparatus by any suitable feed means, not shown. In the normal start-up operation, the filaments are threaded completely through the apparatus. Fluid is introduced through conduit 17 and flows upwardly through plug 14 into chamber 18. The fluid so introduced surrounds needle 12 to elevate the temperature of the incoming filaments. The velocity of the introduced fluid is sufficiently high to produce a zone of substantial turbulence in the flared outlet region 14c of plug 14. This turbulence imparts crimp to the filaments to produce textured yarn 20b. The yarn passes upwardly to form in elongated generally cylindrical wad 20c in the center of chamber 18. This wad is surrounded and confined by balls 19a and 19b. The yarn is cooled in passing through chamber 18 so that permanent crimps are imparted. The diameter of wad 20c is reduced in passing through chamber 22, which results in breaking up of the wad. The resulting textured yarn 20d is removed through a takeup device 29 and passed to a storage zone, not shown.
As previously mentioned, the velocity and temperature of the fluid introduced through conduit 17 are such as to impart the desired degree of crimp in the yarn in the flared outlet section of plug 14 and in tube 18a. If desired, an external heater can be employed to assist in elevating the temperature of the crimping apparatus 10. The texturing fluid passes upwardly and escapes from the open top of chamber 18. When steam is employed as the texturing fluid, it may be desirable to provide vent conduit 21 to remove part of the steam and any condensate which may be formed. Balls 19a and 19b provide sufficient force to retain the yarn wad in a confined central region of chamber 18 for a period of time sufficient to allow the yarn to be cooled to retain a permanent crimp. These balls can be formed of metal, glass or any other material which is inert to the yarn at the temperature encountered. The balls are advantageously of spherical configuration, but this is not essential to the operation of the invention. Stacked members of other configurations can be employed. As illustrated, balls 19a are larger than balls 19b to provide better packing. However, the balls can all be the same size. The height of the balls in chamber 18 should be sufficient to permit the yarn to be cooled before removal from the chamber.
Tapered sleeve 26 and balls 28a and 28b serve to break up the yarn wad which emerges from chamber 18. Sleeve 26 can be formed from a knitted fabric to produce a taper between inlet 23a and outlet 24a. The diameter of opening 24a can advantageously be approximately one-third the diameter of opening 23a. Balls 28a and 28a can correspond in size and material to respective balls 19a and 19b. Outer sleeve 27 and rods 25 can be replaced with a solid sleeve, if desired. If a solid sleeve is so used, a drain should be provided to remove any condensate. The important feature of chamber 22 is the flexible, tapered, inner sleeve and the stacked particles which exert a confining force on the yarn wad as it is breaking up. Materials such as nylon, polyester, polyolefins and Teflon (polymerized tetrafluoroethylene) can be employed to advantage in constructing sleeve 26. Sleeves 26 b 27 can be formed as one sleeve extending from the outer perimeter of plate 24, around the outside of chamber 22 and plate 23, through opening 23a to opening 24a at the inner perimeter of plate 24.
Any type of synthetic fiber which can be textured by the application of external forces at elevated temperatures can be treated by the process of this invention. Typical fibers which can be so treated are polyolefins, nylons and polyesters, for example.
In one specific example of this invention as illustrated in FIGS. 1 and 2, needle 12 has an internal diameter of about 0.06 inch. The end of needle 12 is tapered at an angle of about 45°, as is flared inlet 14a of plug 14. The central passage 14b is about 11/4 inches in length and has an internal diameter of about 0.125 inch. The flared outlet 14c is about one-quarter inch in length and has an outlet diameter of about one-half inch. Steel balls 19a and 28a have a diameter of about one-quarter inch; and steel balls 19b and 28b have a diameter of about one-eighth inch. Approximately 70 percent of the total number of balls in chambers 18 and 22 are the larger balls. Chamber 18 has an internal diameter of about 3 inches, with the depth of balls being about 6 inches. The opening 23a is about 11/2 inches in diameter, and opening 24a is about one-half inch in diameter. Sleeves 26 and 27 are knitted fabric of nylon.
In one specific mode of operation, a bundle of 126 polypropylene filaments having a denier of about 1,800 (approximately 14 denier per filament) is introduced at a velocity of about 750 meters per minute. Steam at 100 p.s.i.g. is introduced at a rate of about 20 pounds per hour. The textured yarn is removed at a velocity of about 500 meters per minute.
While this invention has been described in conjunction with a presently preferred embodiment, it obviously is not limited thereto.