US3389444A - Apparatus for entangling multifilament yarns - Google Patents

Description

June 25, 1968 c. A. FLETCHER ET AL 3,389,444

APPARATUS FOR ENTANGLING MULTIFILAMENT YARNS Original Filed Nov. 22, 1953 6 Sheets-Sheet 1 A --l8 4 4 5- /4 p 6 f8 4 a JV// 4 V AY/7}\ fi a 5/ 5 4 AW f /9 FIG T 2/ P V /6 3 CHARLES A. FLETCHER RICHARD F. DYE/i 3/ INVENTOR.

June 25, 1968 c. FLETCHER ET AL 3,389,444

APPARATUS FOR ENTANGLING MULTIFILAMENT YARNS Original Filed Nov. 22, 1963 6 Sheets-Sheet 2 FIG. 4.

I I J 1 ll FIG. 6.

FIG. 7.

R T R O H m /m P m %m AEWM SD. MR A R M CHO Y B FIG. 8.

June 25, 1968 c, A, F ET HER ET AL 3,389,444

APPARATUS FOR BNTANGLING MULTIFILAMENT YARNS Original Filed Nov. 22, 1963 6 Sheets-Sheet 5 W 96 (ED F/G. 9. F/G. l0.

[5 /5 0w /AV 6 AV/ 6 FIG. FIG. /2.

F/G /3 FIG /4 m 2e //7AV FIG. /5. x

FIG. /6.

CHARLES A. FLETCHER RICHARD F. DYE)? INVENTOR.

ATTORNEYS June 25, 1968 c. A. FLETCHER ET 3,339,444

APPARATUS FOR ENTANGLING MULTIFILAMENT YARNS Original Filed Nov. 22, 1963 6 Sheets-Sheet 4 CHARLES A. FLETCHER RICHARD F. DYER INVENTOR.

A TTORNE Y5 June 25, 1968 c, A FLETCHER ET AL 3,389,444

APPARATUS FOR ENTANGLING MULTIFILAMENT YARNS Original Filed Nov. 22, 1953 6 Sheets-Sheet 5 F/G. l9.

CHARLES A. FLETCHER RICHARD F. DYER' INVENTOR.

A T TORNEYS June 25, 1968 c. A. FLETCHER ET AL 3,389,444

APPARATUS FOR ENTANGLING MULTiFILAMENT YARNS 6 Sheets-Sheet 6 Original Filed Nov. 22, 1963 FIG. 22.

CHARLES A. FLETCHER RICHARD F. DYER INVENTOR.

United States Patent 3,389,444 APPARATUS FOR ENTANGLING MULTIFILAMENT YARNS Charles A. Fletcher and Richard F. Dyer, Kingsport, Tenn, assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Application Nov. 22, 1963, Ser. No. 325,719, now Patent No. 3,286,321, which is a continuation-impart of application Ser. No. 183,448, Mar. 29, 1962. Divided and this application Nov. 15, 1965, Ser. No. 516,820

1 Claim. (Cl. 28--1) ABSTRACT OF THE DISCLOSURE A multifilament entanglement jet assembly which includes plural jets mounted within a housing that is designed for both supplying and exhausting the fluid treating media to the jets.

Crossdeferences related applications This is a divisional application of US. Ser. No. 325,719, now US. Patent No. 3,286,321, which in turn is a continuation-impart of our parent application U.S. Ser. No. 183,448, now US. Patent No. 3,220,082.

This invention relates to a method and apparatus for the treatment of textile yarns. More particularly, this invention concerns an apparatus wherein a new type jet is supplied with high velocity gas which imparts spaced entanglements to continuous filament synthetic yarns and tows.

For many years various textile treatment jets utilizing high velocity gas have been used in the textile industry for imparting to yarns a variety of physical properties and appearances. Illustrative of these jets are those shown in US. patents such as 2,067,251, 2,100,588, 2,379,824, 2,460,390, 2,661,588, 2,737,688, 2,884,756, 2,924,868, 2,932,935 and 2,962,794. The several jets which have been described in the prior art have the capability of imparting many different treatments to yarn. However, generally speaking, the prior art jets are best suited for a specific treatment. As new and improved configurations or physical properties for yarns are arrived at, treatment jets are needed for use in manufacturing these new products.

A treatment known for some time in the industry as intermingling, entangling or entwining yarn is now being used to improve the handling of zero twist yarn in various textile operations such as crimping, beaming, sizing, weaving, twisting, knitting and the like where various amounts of twist have heretofore been used and are normally required. Many of the existing jets mentioned above may be used for producing such type yarn, generically referred to as entangled yarn. However, it is believed apparent that the development of a specific simplified jet construction and method for treating yarn in this manner would be of substantial value to the trade. It, therefore, seems apparent that providing new jets and method which fulfill certain special needs of the industry represents a useful result. After extended investigation we have discovered certain relatively simple jet constructions and methods for the utilization thereof which we believe to embody new and unobviou s features.

The new jets of this invention are particularly of a construction for the production of the aforementioned en tangled yarn and have a number of advantages over any of the previously available jets, such as low volume and low pressure air or other fluid requirements, one piece "ice interchangeable jet inserts, relatively small size, no adjustment, and simplicity of design.

This invention has for one object to provide a method that lends itself for use in the treatment of yarns and tows for purposes of entangling, entwining or intermingling, as mentioned above, of the individual filaments of a running strand thereof. Another object is to provide a method which may be utilize-d to process the yarn continuously or to secure randomly spaced treatment along the yarn so as to give the yarn handling characteristics similar to that of yarn which has been twisted. A further object is to provide a method for treating yarn so that the yarn is relatively free of any loops or other noticeable discontinuities but has a marked tendency to remain in a coherent bundle of filaments in textile operations. Another object is to provide a process of the type indicated wherein heated gas is employed thereby reducing gas input to the process. A further object is to provide a process utilizing a plurality of jets in series thereby minimizing the severity of gas action on the yarn being processed. Still another object is to provide a process wherein the yarn is processed in a jet in which the jet insert is of a certain composition and finish. Still another object is to provide a method that is capable of stripping excess liquids off running strands of yarn in operations such as wet spinning, sizing, dyeing, hot liquid drafting and the like so as to facilitate further treatment or winding of the yarn. Another object is to provide a method which may be used for heating yarns with hot gases or other fluids in connection with drafting and relaxing operations. Still a further object is to provide a method having utility as a frictionless yarn guide. A particular object is to provide an internally entangled yarn of a new structure. A further object is to provide new jet construction for facilitating the carrying out of the aforesaid process. Other objects will appear hereinafter.

In the broader aspects of this invention our new treatment jet has two distinct parts; a jet body, the purpose of which is to receive and distribute the pressurized gas or other fluid (most frequently clean, dry air) and to support the other part which is the jet insert, This jet insert is a special construction for use in treating the yarn by directing onto the yarn a pressurized fluid received from the jet body in the form of high velocity jet streams. It will be observed as the description proceeds that we have provided a construction particularly versatile in this respect by virtue of our construction being susceptible of including certain inserts.

For assistance in a further understanding of this invention reference will be made to the attached drawings forming a part of this application.

FIGURE 1 is a side elevation view largely in section illustrating our simplified jet.

FIGURE 2 is a semidiagrammatic view of one illustrative process embodiment of textile operation wherein our new simplified jet construction may be used.

FIGURE 3, likewise, is a sernidiagrammatic view somewhat in the nature of a flow sheet of another embodiment of textile operation wherein our new simplified jet construction may be utilized.

FIGURE 4 is still a further semidiagrammatic view of process and apparatus arrangement wherein the new simplified jet construction of the present invention may be employed.

FIGURE 5 is a side elevation view of a modified jet insert such as may be used in our simplified jet of FIG- URE 1 so that other functions may be accomplished.

FIGURE 6 is an end elevation of the insert structure of FIGURE 5.

FIGURES 7-15, inclusive, are illustrations similar to FIGURES and 6 of other insert constructions and configurations.

FIGURE 16 is a side sectional view Showing another way of mounting the inserts in the jet.

FIGURES 17 and 18 are diagrammatical illustrations on a considerably enlarged scale of some of the yarn structures fed and obtained using the various jet constructions referred to above for the processing of yarns.

FIGURE 19 is an end sectional view a jet assembly featuring a yarn threading slot.

FIGURE 20 is a top sectional view of the same slotted jet assembly.

FIGURE 21 is a side elevation cross-section of a compound jet arrangement.

FIGURE 22 is a side elevation cross-section of a modified arrangement for the jet of FIGURE 1.

FIGURE 23 is an enlarged longitudinal view of a moderately entangled yarn.

FIGURE 24 is an enlarged longitudinal view of a very highly tightly entangled yarn.

Referring to FIGURE 1 this invention is there shown in one of its simplest forms. The jet body, designated by the numeral 1, is drilled and counter-bored to receive the pressurized gas conduit, 2, at the bottom and also drilled through the sides to receive a ceramic jet insert, 3, in such a manner that the center portion of the insert is incapsulated in the annulus, 4, formed by the extension of the hole previously drilled for the gas conduit. The insert 3 itself is tubular in shape and has two inlets, 5, which direct the pressurized gas from the annulus, 4, into the treatment chamber, 6. The yarn strand to be treated passes through the treatment chamber, 6, as shown by the alternated filament bundle 7.

Although an understanding of the functioning of this simplified jet is apparent to some extent from the foregoing description, a further understanding will be had from a consideration of the following examples:

EXAMPLE I This example is in accordance with FIGURE 2, concerns the utilization of the jet as applied to a dry spinning process for the production of 55 denier, 13 filament dull entangled acetate continuous filament yarn.

The yarn strand, 17, is formed by the extrusion of the acetate dope through a spinnerette jet, 18, into a spinning cabinet, 19, where the individual filaments are partially cured and combined into a single yarn strand. The yarn then passes out of the cabinet and contacts an oil applicator roll, 20, where a yarn lubricant, 21, is applied to it. It then passes around a godet roll, 22, and into a collector housing, 23, which contains the treatment jet, 11, of this invention. Pressurized dry, clean air is supplied to the jet through conduit, 12, and the undesirable oil-laden exhaust from the jet is collected and removed by the collector housing and connecting gutter, 23, as described in more detail in companion application Ser. No. 138,943, now US. Patent No. 3,103,731. The yarn passes out of the housing, 23, over ceramic guides, 24 and 25, and into a conventional traverse mechanism, 26, from whence it is wound into a package for use in subsequent textile operations. The conditions in the vicinity of the jet are as follows:

Yarn speed660 meters/ min.

Yarn tension at the treatment jet-5 grams (0.0909

g./den.)

Jet supplied with 15 p.s.i.g. treatment air The yarn produced has the following physical properties:

55 denier-13 filament-0 twist Average entanglement spacing-4 inches 2.3 percent by weight lubricant 25 percent elongation 1.2 grams/ denier (dry) strength EXAMPLE II Another example of the use of the invention is illustrated in FIGURE 3, as applied to the drafting and entangling of a multifilament, continuous filament polyester fiber. The yarn strand, 30, is withdrawn from an unoriented supply package, 31, and passes through a tension gate, 34. It passes over a ceramic guide, 35, and onto a drafting input and advancing roll set, 36. A hot pin, 37, heats the yarn; and it is oriented or drafted by the drafting output and advancing roll set, 38. It then passes through the treatment jet, 32, supplied with pressurized air through conduit, 33, from a source not shown, and is wound into a yarn package, 39, by a conventional winding device. The treatment jet in this example imparts to the yarn at random intervals an entwining or intermingling of the individual filament around each other. The resulting yarn strand is bound together by these entwined spots, and, in subsequent textile operations, handles in the same manner as yarn that has been twisted. The conditions in the vicinity of the treatment jet are as follows:

Yarn speed-422 yds./ min. Yarn tension9 grams (0.128 g./d.) Jet supplied with 20 p.s.i.g. dry air The yarn produced had the following properties:

70 denier, 33 filament Average spacing between entanglements2 EXAMPLE III A third example of the utilization of this new and simplified jet is illustrated in FIGURE 4, as applied to the production of a 2700 denier, 200 filament textured filament, modified acrylic yarn, such as described in greater detail in companion Haynes US. Patent No. 3,- 099,064. The yarn strands, 40, from the supply packages, 41, of previously oriented fiber pass through a set of feed rolls, 42, into a set of treatment jets, 43, supplied with pressurized air from a source not shown where fibers are indivdually entangled. They are then combined into a tow, 44, by passing between guide pins, 45, and crimped in a crimping machine, 46. The crimped tow, 47, is then heat set and relaxed under zero tension in an oven, 48, and separated into individual ends, 49, again for winding on a conventional winding device, 50. The entanglement in this process is used in the place of twist to maintain the integrity of the individual strands while they are being processed in tow form so that, upon completion of the heat setting, they can be split apart and wound on individual package. The texture of the yarn is derived from the crimping and not the entangling. The operating conditions in the vicinity of the treatment jet are as follows:

3 percent overfeed between feed roll and crimper Yarn speedmeters/ minute Air pressure supplied to treatment jet40 p.s.i.g.

The yarn produced is characterized by interfilament entanglements at /z to 1" intervals and a crimped texture which imparts to it a unique appearance and hand, particularly suitable for use in carpets, upholstery fabrics, and other textile products.

The jet constructions used in the above examples consist of ceramic tubes in a pressurized annulus, as illustrated in FIGURE 1. The preferred design of the insert and its relationship with the annulus can be further described by defining certain ratios and parameters between the various dimensions and the yarns to be treated. Referring to FIGURE 1, the yarn passage diameter, 6, preferably is 5 to 20 times the yarn diameter. The length of the yarn passage, 6, preferably is 3 to 15 times its diameter. The diameter of the air passage, 5, preferably is l to /2 times the diameter of the yarn passage, 6. The length of the air passage, 5, preferably is 4 to 10 times its diameter. The interior edges at the ends of the yarn passage, 6, are chamfered or rounded so as to eliminate possible yarn damage and increase running efficiency. The diameter of the insert is selected so as to allow sufficient and proper air supply to the air passages, 5.

The process of this invention thus is felt to constitute an improvement over the process as disclosed in companion, co-pending Dyer application S.N. 75,396 in that the volume of air required for attaining an equal amount of filament interweaving is substantially less.

EXAMPLE IV A comparison was made of an orifice plate/venturi jet as described in US. Patent 2,924,868 and Ser. No. 75,396, with a semi-taper jet such as shown in FIGURE 7. The yarn passage '(76) in the semi-taper jet was 0.101" in diameter with a 4.3 expanding taper (72) on the outlet side. The air hole entrances (73) were straight and of a 0.080 diameter. Both jets were run on '150/38/0 bright acetate yarn at similar conditions of yarn speed and tension.

The orifice/venturi jet of the prior art required 22 p.s.i.g. air pressure and an air usage of 6.25 c.f.m. of free air at standard conditions to obtain entanglements of 3 to 6" spacing. The jet of FIGURE 7 of this invention required only 6 p.s.i.g. air pressure and two cubic feet per minute of free air at standard conditions to produce the same degree of entanglement.

Although in the above description one type of insert for the jet has been described; there are several variations which can be applied to the insert so as to achieve different effects. It is advantageous to use a jet body equipped with interchangeable inserts especially suited for imparting a desired treatment to yarns of different chemical and molecular structure. These yarns may better use diiferent inserts because of their varied physical properties and handling characteristics.

It has been found that the material used for the inserts 3 has a substantial efie'ct on the process. This appears to be related to the type of surface finish treatment chamber 6 as well as possibly the electrical conductivity of the insert material and its place on the triboelectric scale relative to the position of the synthetic filaments being processed. The following example illustrates this.

EXAMPLE V Using the apparatus of FIGURES 1 and 2, a 150/ 38/ 0 cellulose acetate yarn was delivered to the treatment jet at 700 meters per minute at a tension of 12 grams. The air pressure to the jet was varied in steps of 5, 7.5 and p.s.i.g. Four insert materials were tested by collecting yarn samples and examining them for the distance between entanglements. The results are summarized in the following table.

Average Entanglement Spacing, Inches Air Pressure to Jet:

4. ll 7. 0 (l. 5 30. U 2. 2 2. 1 2. 3 10. 0 1. 5 1. 2 I. 2 5. 0

Brass Insert Surface Finishes, RMS Micro Inch 32 RMS 16 RMS 8 RMS RMS Average Entanglement Spacing, Inches Air Pressure to let:

7% p.s.i.g 6 5 3 1. 5

In the foregoing table, it can be seen that inserts made from metallic materials such as brass and steel tend to produce somewhat closer entanglement in the yarn than a ceramic or plastic insert. It is also indicated that the surface finish in the yarn treatment chamber 6 has a major effect on the frequency or spacing of the entanglements. A highly polished .25 RMS mirror-like finish in the chamber 6 produces much closer spaced entanglements than an 8 R-M-S micro inch finish for a given insert material, size and air pressure.

In some cases, it has been found to be desirable to treat the yarn a plurality of times to increase the frequency of entanglement without increasing the severity of the effect of the gas on the yarn. -It has been found that under certain circumstances very high air pressures, when used in small inserts, cause excessive broken filaments. This combination of high air pressure and small inserts may also cause excessively tight interweaving of the filaments at random spots along the yarn, causing a change in yarn appearance at these spots which show up as flashes or short streaks as shown in FIGURE 24 when the yarn is Woven into fabric. The following example illustrates the substantial reduction in air pressure required to produce a given level of entangernents when the yarn is treated a plurality of times in a series of inserts as compared to a single treatment in a single insert.

EXAMPLE VI Example VI of this invention is illustrated in FIGURE 21 as applied to a dry spinning process for the production of denier, 38 filament, bright, entangled acetate con tinuous filament yarn. In this embodiment, a series of jet assemblies, 213, including an incapsulated insert 3, is used to treat the yarn strand, 215. The jets are contained in a single housing, 212, having receiving and exit eyelet means 210, for the purpose of collecting lubricant blow-off which is then carried away by the exhaust systern, 214. Process air is supplied from the plenum chamber, 21 1, on top of the collector housing.

The table below describes the operating conditions and resultant fabric appearance of yarn from this apparatus.

Yarn Speed, 720 meters/minute Takeup tension, 15 grams and 24.

The inserts used in this example had a 0.052 diameter yarn passage 6 and 0.040" diameter air entrance holes 5.

EXAMPLE VI I Another convenient form that the jet design may take is to build the jet into the air header directly. This is illustrated in FIGURE 2.2 as applied to a dry spinning process for the production of 150 denier, 3 8 tfilament, dull, entangled, continuous filament acetate yarn. In this configuration the jet assembly is designed in the shape of a threaded plug, 226, which screws into a lubricant blowoff collector and exhaust pipe 227. Air is supplied through the bottom, 228, by conventional means. The yarn strand to be treated is designated by the numeral 229.

The following table describes the operating conditions and entanglement produced from this apparatus. The insert had a 0.101" diameter yarn passage and 0.081" diameter air entrance holes.

Yarn speed-060 meters/min u (e The design,

advantages of this apparatus are simplicity of compac ness and low cost of fabrication. The pipe is positioned parallel to the spinning machine and jets are located in it as needed to treat the ends of yarn as they pass to the yarn take-up machines.

While the insert illustrated in FIGURE 1 has two air passages of a cylindrical configuration, other shapes and arrangements of air passages along the yarn passage are desirable for imparting different treatments to various kinds and sizes of yarns. For example, the treatment jet used in the third process example, FIGURE 4, may have as its insert the design illustrated in FIGURE 5. This figure illustrates an insert with four air passages, 5, of cylindrical configuration whose axis intersect the axis of a cylindrical yarn passage, 6, and are perpendicular to each other. FIGURE 6 is an end elevation view of the same insert. FIGURE 7, a sectional side elevation view, illustrates an insert with a conical configuration, 72, on one end of cylindrical yarn passage, 76, and conically shaped air passages, 73. In this jet the included angle of the tapered portion, 72, has been found to be most effective when it has a value of 4 to with 7 being a preferred value. This diverging portion of the jet forms the yarn exit from the tube, 76, and promotes self-threading of the jet. This self-threading feature makes this jet particularly useful as a frictionless thread guide for use in a beaming operation where the yarn strands must be supported and guided over several 100 ft. at times. For this use the diameter of the cylindrical part of the passageway, 76, should be as small as possible to reduce air usage requirements and may be from 2 to 10 times the yarn diameter. With low air pressures of 0.1 to 5.0 p.s.i. gauge, the yarn bundle is supported on a film of gas throughout the passageway, 76, as a minor portion of the gas escapes through the yarn entrance, and a major portion escapes through the yarn exit taper, 72. This division of the gas exhaust gives a gentle forwarding action to the yarn which helps to overcome atmospheric air drag when the yarn is traveling at high speeds or tension from the centrifugal forces generated as the yarn balloons out in the course of removal from the end of a supply package. The small size of the yarn passage permits the use of a minimum of air and thus avoids any derangement of the yarn filaments by the jet air guide 0 which would cause them to take on an entwined, entangled, or loopy appearance. Of course, if desired, higher air pressures of say 5 to p.s.i. may be used to cause any desired degree of entanglement or looping of the yarn filaments as well as the aforementioned yarn guiding effect.

The process and jets of this invention also have a wide range of adaptability in producing different types of products. This is illustrated in the following example.

EXAMPLE VIII The semi-taper jet of FIGURE 7 was set up as shown in FIGURE 2 on a yarn spinning machine. The conditions of operation were varied to produce three distinctly V different appearing yarn products as judged by the appearance of the yarn in fabric.

220 denier, 50 filament cellulose acetate yarn pigmented a blue color and spun at 714 m./m. was used in each test.

In the first test, the jet was operated at a pressure of 7.5 p.s.i.g. and the winding tension of the yarn was 15 grams. Under these conditions the filaments of the yarn had a gentle type interweaving with an entanglement spacing of two inches when examined carefully under a microscope. Its appearance was substantially like that of FIGURE 23. When woven into fabric as filling, no difference in appearance could be detacted between it and untreated yarn; yet there was no need to twist the treated yarn to make it weave acceptably while 1.0 t.p.i. of twist was required in the untreated yarn to avoid excessive broken filament damage and fuzziness in the fabric.

In the second test, the jet was operated at 30 p.s.i.g. air pressure and the yarn tension was raised to 20 to 25 grams. This caused the interweaving of the filaments to become much more severe and acute. It caused a marked change in the luster of the yarn at the points of very tight entanglement, 103 and 1M. The yarn appeared somewhat as in FIGURE 24 with some flaring of the filaments between the entangled spots and with the spots of entanglement being about /8 to A" long and spaced about /2 to 1" apart. When woven as filling into fabric, the spots of tight entanglement showed up as short flashes or streaks and tended to simulate the general effect of a skip dent type weave. By transmitted light, the fabric appeared to contain a thick and thin type yarn with randomly occurring short lengths of thin yarn appearing throughout the fabric.

In 'the third test, the jet was operated at 66 p.s.i.g. air pressure and the winding tension was reduced to 12 grams. In this case, the yarn took on an over-all delustered and fuzzy effect. The yarn appearance was loopy with spots of extremely tight filament interweaving alternating with randomly occurring arch shaped loops as shown in FIGURE 18. When woven as filling in a fabric, the fabric had the appearance of containing a staple yarn of poor uniformity plus some of the skip dent effect noted in the second test. The surface of the fabric was not as slick and lustrous as that of tests 1 and 2 and somewhat resembled a wild silk yarn fabric. Some of this yarn was also knit into a sock fabric in comparison with an untreated yarn sample having 1 t.p.i. of twist. The treated yarn imparted more thickness to the knit sock and gave it a softer hand than the untreated yarn. The specific volume of the treated yarn was 42 cubic inches/pound as compared to 33 cubic inches/pound for the untreated yarn.

From the foregoing, it can be seen that the jets and process of this invention have a wide versatility for the treatment of continuous filament yarn to (1) interweave the filaments to substitute for twist without changing the appearance of the yarn; (2) to interweave the filaments tightly at spaced intervals to cause luster variations and novel effects in fabrics and; (3) to tightly in terweave the filaments at closely spaced intervals and form long arch shaped filament loops between the spots of entanglement to impart a softer, less slick hand to the yarn and to slightly increase its bulk. The spots of tight entanglement serve to securely lock and arch shaped filament loops in place in the yarn without need for twist or chemical filament binders or adhesives.

The air entrance passages, as 5, may be either straight as shown in FIGURE 1 or converging as shown in FIG- URE 7. The converging type air entrance is helpful in accelerating the treatment gas to a high velocity to enhance the entangling or looping and entangling of the yarn filaments when these effects may be desired. An included entrance angle of 20 to 90 in the air entrance passages allows the use of lower gas pressures for a given level of filament entanglement or loopiness due to the increased kinetic energy imparted to the gas stream by accelerating it to a higher velocity by means of the converging air passages, 5.

In FIGURE 8 is shown an enlarged portion of a preferred gas entrance, 83, to a jet of the class described. This type entrance to the yarn tube has very low losses due to gas friction and turbulence and in certain instances it may be possible to treat several thousand ends of yarn at substantial savings in cost even though the initial cost of fabrication of the jet may be increased as compared to the straight gas tube, 5, of FIGURE 1. In this case a diameter for the yarn passage is selected depending on the yarn denier and the type of treatment desired. In the case shown a value of d is selected for the inside diameter of the yarn passage. The outside diameter of the insert tube is then assigned the value of 1.6d, giving the tube a wall thickness of .3d. The diameter of the gas inlet is .50d, and the entrance to the gas inlet tube is assigned two radii which merge into a straight cylindrical passage. The first entrance radius is given a value of .lOd, the center point of this radius being located .lOd from the outer tube surface and .37d from the axis of the gas entrance. This first radius is merged with a second radius having a value of .1503, the center of which is located .lSd from the outer surface of the tube and .5011 from the axis of the gas passageway. All these dimensions are based on a longitudinal crosssection as shown in FIGURE 8. It will be recognized that these values will be slightly different in other vertical cross-sectional planes that do not pass through the yarn passage axis due to the cylindrical shape of the outer surface of the jet insert.

FIGURE 9, a sectional side elevation view, illustrates a rectangular yarn pasage, 96, and cylindrical air passages, 95. The rectangular yarn passage promotes eddy currents andair turbulence and is useful for increasing the entangling forces on the yarn filaments. FIGURE 10 is an end elevation view of the same insert.

FIGURE 11, a sectional side elevation view, illustrates an insert with three alternately spaced cylindrical air passages along a cylindrical yarn passage, 6. FIGURE 12, a sectional side elevation view, illustrates an insert with one cylindrical air inlet, 5, intersecting a cylindrical yarn passage, 6. FIGURE 13, a side elevation view, illustrates an insert with cylindrical air passages which intersect the cylindrical yarn passage tangentially. FIGURE 14 is a sectional end elevation view of this same insert. This form of jet is useful when it is desired to impart a false twist to the yarn either for the purpose of improving the compactness and ease of handling of the yarn in an immediately prior or subsequent process step or for the purpose of achieving a curly crimp in the yarn filaments as described in companion Hoskins U.S. application Ser. No. 826,714.

While the outer wall of the gas entrances is depicted in FIGURE 14 as tangential with the wall of the yarn pasage, it will be recognized that the axial offset of the gas passage, 5, from the axis of the yarn passage, 6, may be greater or less, depending on the amount of torsional force it is desired to impose on the yarn bundle. If only a low degree of false twist, say a few turns per inch, is desired in a frictionless thread guide such as shown in FIGURE 7, then the axis of the gas entrance tubes, 5, may be displaced only a few thousandths of an inch from the axis of the yarn passageway, 6. Such a jet configuration is particularly advantageous in handling delicate yarns to avoid damaging friction over guides and preventing excessive filament separation or entanglement by means of the low level of false twist imparted. Conversely with larger axial offsets and high air pressures, a high degree of filament entanglement or entanglement and loopiness together with a moderate level of false twist may be imparted to a yarn if so desired.

FIGURE 15, a side elevation sectional view, illustrates a V shaped yarn passage, 1%, with an included angle from 170 to and cylindrical air passages, 5. Such a configuration is helpful when the jet is located at a point where a change in direction of the yarn path is desired, but space or other limitations require that the yarn must be entangled or looped simultaneously with the change in yarn path.

FIGURES 19 and 20 illustrate a jet assembly which features a yarn threading slot for improved operating efficiency and convenience. The slotted jet allows a running strand of yarn to be introduced into the treatment chamber simply by sliding the filaments through the slot. In continuous processes normally associated with the extrusion of synthetic fibers by melt, dry, or wet spinning this feature is highly desirable because the running strand of yarn does not have to be broken in order to thread it through the jet.

The jet consists of an upper body, 60, a lower body, 61, a spacer, 62, a slotted ceramic insert, 63, a pressurized gas conduit, 64, and conventional threaded fastener 65. The slot is designated by the numeral 66.

The width of the slot, 66, is dependent upon the thick ness of the spacer, 62, and can be varied to accommodate large or small filament cross-sections. For yarns with filament diameters in the range of .0005" to .002 a .004" spacer is preferred; larger filaments require a thicker spacer. The slot entrance has been provided with radii, 67, to facilitate sliding the yarn into the treatment chamber.

A gentle flow of air issues through the fine slot in the insert thus insuring that the yarn filaments are not blown out of the treatment chamber by the more turbulent conditions existing therein. If desired the insert can be rotated with respect to the jet body after threading, misaligning the slots thus providing an additional means of preventing the escape of any filaments from the treatment chamber. The flanges, 68, on either end of the insert serve to position the insert in the jet body and to prevent the snagging of filaments in the cracks formed by the junction of the outer diameter of the insert and the inner diameters of the jet bodies.

The jet of FIGURE 15, when used solely as a yarn guide, has particular advantages over the prior art snubbing guides which rub and abrade the yarn rather then floating it on a film of gas. These variations on the design of the insert are not all inclusive but serve to illustrate some of the possible insert configurations within the spirit of this invention. The inserts illustrated in FIG- URES l and 19 are preferred for producing moderately tight entanglement on yarns from 35 to 500 denier, for example, in acetate spinning operations similar to the one illustrated in FIGURE 2; whereas, the inserts of FIG- URE 5 and FIGURE 11 are better suited for producing heavy entanglement on larger deniers in processes similar to the bulking of modified acrylic yarns as illustrated in FIGURE 4. When only a mild entanglement is desired, the insert of FIGURE 12 is preferred. If it is desired to have the insert exert a slight pull on the yarn to facilitate withdrawal or threading or to act as a frictionless yarn guide, a jet similar to FIGURE 7 is preferred. If it is desired to eliminate any slight twisting or swirling of the yarn strand, then an insert similar to FIGURES 9-10 is preferred. The inserts of FIGURES 7 or 8 are best suited for imparting a bulk or texture to the yarn so as I 1 to give it the appearance and hand of staple yarn. If a false twisting effect is desired, the insert of FIGURES l314 with tangential air passages is preferred. If it is desirable to direct the exhaust from the jet downward or upward, an insert similar to FIGURE can be used.

All of these inserts exhibit a tendency to remove excess liquids from running strands of yarn; however, the in serts of FIGURES 1, 5, 7, 9, 11, 15 and 19 are preferred for this use. Inserts similar to the ones illustrated in FIG- URES 1, 7, 9 and 19 are preferred when it is desired to obtain novelty delustred effect on bright or semi-bright yarns. The configurations of the air passages illustrated are typical of those that can be used; however, certain other shapes would still be within the spirit of this invention. The cylindrical air passages of FIGURES 1, 5, 9, 11, 12, 13, 15 and 19 are the easiest to form and give very good results, but special effects and higher efficiencies can be realized in using the conical, converging nozzle or other similar configurations of FIGURES 7 and 8.

Reference is now made briefly to FIGURE 16. To achieve a versatile apparatus, one method of mounting the insert in the jet body is accomplished by utilizing O ring seals, 29, and a retaining ring, 23, as illustrated in FIGURE 16. For applications where a permanent joint is desired, the two parts are joined by cement, 8, as illustrated in FIGURE 1.

While it is not desired to be bound by theory, a further understanding perhaps may be had from the following explanation:

This invention it is thought may be considered an improvement over existing theory long known to those skilled in the art of treating yarn strands with high velocity gases or liquids. Simply stated, the jet streams of high velocity gas impinge on the yarn perpendicularly or at a slight angle to its axis and cause the individual filaments to be separated from each other and rearranged in an entwined, intermingled fashion as they exit from the treatment zone. This is further apparent by referring to FIGURE 17, where a short length of zero twist yarn is depicted with its filaments arranged in a parallel manner and comparing it to FIGURE 18, which depicts two entangled spots, 103 and 104, in a short length of yarn treated with an insert similar to that of FIGURE 1. It can be seen that, in bright or semi-bright yarns, entangled spots along the strands of otherwise zero twist yarns have different reflective properties as described in companion Dyer application Ser. No. 145,877, new U.S. Patent No. 3,103,098. This results in a novel effect when these yarns are woven and finished into fabrics of various constructions. When jets of this invention are used to strip excess liquids off running strands of yarn, the action of the high velocity jet streams on the yarn in the treatment area penetrates through the yarn strand, atomizes any excess liquids present, and expels them as aerosol from either end of the jet insert. This can be further enhanced by utilizing hot or warm gas to vaporize some of the excess liquid.

The use of a heated gas is often desirable in the entanglement process. It is thought that this may be so because most man-made fibers are thermoplastic and have a reduced strength at elevated temperatures. This means that as the temperature of the treating gas is raised, the filaments are warmed and become less stiff. The filaments thus become easier to bend and flex so that they interweave with each other more readily. Thus lower gas presshures can be used to obtain a given degree of entanglement of the filaments in a yarn when warm to hot air is sed. The temperature need not be as high as the second order transition temperature; however, to give good results.

EXAMPLE IX This example illustrates the effect of treating cellulose acetate 150 denier, 38 filament bright yarn at a yarn speed of: 714 mm. while it was being wound at 8.5 grams tension. The apparatus setup was like that of FIGURES l Air Temperatures in C.

Air Air 25 0. Air

C. Air

Average Entanglement in Inches 19. 5 (i. G 5. 7 7. 4 7. 7 2. 3 1. ti 1. (5 2.2 1. 6 1. 7 1. (3 1. 1 1. 3 1. l. 1.5

It can be seen that with 50 to 130 C. air the same entanglement was obtained with 3 p.s.i.g. air as was obtained with 25 C air but at 6 p.s.i.g., a 50% reduction in air pressure. Or that only 6 p.s.i.g. air at 100 C. was required to give 1.6 entanglement spacing instead of more than 9 p.s.i.g. of 25 C. air.

The heating of yarns, particularly the polyester and polyolefin types, in drafting and relaxing processes can be readily accomplished using this type of jet due to the extremely efficient heat transfer obtained when the hot jet streams separate and incapsulate each individual filament. The jets of this invention can be designed and operated so that the yarn appearance and filament arrangement before and after passage through the jet remains the same, or the appearance remains the same but the filament arrangement is changed, or both the appearance and filament arrangement is changed as may be seen from the foregoing. The treatment jet of this invention is a relatively simple apparatus featuring only two parts, neither of which requires adjustment. It is highly versatile in that any number of different inserts can be used in the same jet body to impart many different treatments to various running strands of yarn. It can be fabricated from ceramic materials, thus eliminating wear caused by erosion due to the air flow or yarn abrasion and insuring a uniform quality of treatment over long periods of time. It is small in size and can be easily applied to existing textile operations where other type jets will not fit. It can also be adapted for slot threading thus improving operating efiiciency and convenience. In summary, this unique jet, featuring small interchangeable ceramic inserts, can be used in the textile industry to entangle, loft, bulk, heat, deluster, texture, false twist and remove excess liquids from running strands of yarn.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

We claim:

1. An apparatus for cntangling multifilament yarns comprising a housing member enclosing a plurality of spaced jets arranged in series, eyelet means in said housing for receiving the yarn to be processed and for permitting the removal of the processed yarn; each of said jets including an incapsulated insert through which the yarn may be fed and gas may be exited, and said housing including means for supplying gas to and withdrawing exited gas from said jets.

References Cited UNITED STATES PATENTS 3,009,309 11/1961 Breen et al. 3,110,151 11/1963 Bunting et al.

FOREIGN PATENTS 554,149 3/1958 Canada.

LOUIS K. RIMRODT, Primary Era/nine];

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