IE51938B1 - Process and apparatus for making coherent yarn - Google Patents

Abstract

A process and apparatus for intermingling filaments of a yarn or yarns with a fluid-jet device employs long narrow tubular guides to peripherally constrain vibrations in the yarn upstream, and optionally downstream, of the intermingling zone. The apparatus and process can be used with differentially dyeable bulked supply yarns to make a heather dyeable yarn for carpets.

Description

Process and Apparatus for Making Coherent Yarn Technical Field The present invention relates to a process and apparatus involving a fluid-jet device for intermingling filaments in a continuous filament yarn or yarns, including combining a plurality of yarns to produce a larger coherent yarn. More particularly, the invention relates to an apparatus and method involving a tubular guide for guiding yarn into a fluid-jet filament intermingling device.

Background Art Fluid-jet filament intermingling devices have long been used to make twist-free coherent yarns and also to combine a plurality of yarns into a single coherent yarn having the filaments of the various yarns intermingled with one another. See for example U.S.P. 3,364,537 (Bunting and Nelson). The filaments in such yarns can be intermingled to varying degrees from slight to extensive depending upon the nature of the component yarns, apparatus design and the severity of the intermingling conditions. Consequently, the processes lend themselves to a variety of applications from combining smaller yarns into a larger yarn, i.e., doubling, to combining differently colored or differently colorable yarns to make various types of mixed-color styling yarns such as marl and heather yarns with either bulked or non-bulked yarns.

U.S.P. 4,069,565 (Negishi) concerns such an apparatus and process for making a textured (bulked) multifilament yarn provided with compact portions and 51838 - 3 open portions alternately distributed along its length. The process comprises contacting a running bundle of filaments with two curved members longitudinally spaced apart from each other with the thread line being bent at each point of contact. A running passage of the filaments is formed under tension in the entire space between the two members. Then at least one stream of fluid is discharged against the bundle in said passage from one side of the bundle so that individual filaments of the bundle are vibrated and randomly and intermittently crossed in the direction of the discharged fluid flow. For effective operation the threadline must be bent at each point of contact both upstream and downstream of the intermingling zone. Also the position of the fluid flow between the points of contact is taught to be critical, preferably at the midpoint between them.

U.S.P. 4,059,873 discloses a process for making a bulked continuous filament heather yarn by subjecting a plurality of crimped continuous filament yarns of different color and/or dye receptivity, in which the filaments have been disentangled to substantially remove yarn coherency, to an intermingling zone from which the combined yarn is drawn at a rate less than the feed rate into the zone. The fluid flow not only intermingles the filaments but also forwards the resultant yarn from the intermingling zone. The yarn is shown being bent substantially at right angles to the yarn passageway upon both entering and leaving the intermingling zone.

Objects of the present invention include an improved process (and apparatus) for making a coherent yarn, particularly a bulked yarn, with a fluid jet device which does not require bending of ( the yarn path as it enters or leaves the intermingling zone. Other objects include a more energy efficient process for combining yarns, particularly for making a bulked heather-dyeable carpet yarn, and an economical process operable at higher yarn speeds.

Brief Description of the Drawings FIG. 1 is a schematic elevational view of an apparatus of the invention having a tubular yarn guide coaxially positioned upstream and also downstream of a fluid-jet filament intermingling device.

FIG. 2 is a schematic elevational view of a preferred apparatus of the invention having a tubular yarn guide upstream only of the jet device and which is preceded by a tensioning zone and snubbing pins for removing filament entanglement from the supply yarns.

Disclosure of the Invention This invention provides an improved process for intermingling filaments of a continuous multifilament yarn or yarns to make a more coherent yarn therefrom by forwarding yarn or yarns through a fluid-jet filament intermingling zone which includes an enclosed yarn passageway with a yarn entrance and a yam exit and preferably with a substantially cylindrical form in between them, and in said passageway impinging at least one high velocity jet of compressible fluid upon said yarn or yarns to vibrate and to intermingle filaments thereof while preventing lateral filament vibrations in the yarn or yarns upstream of said zone, and then withdrawing the more coherent yarn from said zone wherein the improvement comprises forwarding and withdrawing said yarn or yarns to and - 5 - ( from said zone along a path which is substantially coaxial with said passageway and peripherally constraining lateral filament vibrations in said yarn or yarns immediately upstream of said zone by tubular confinement which extends from the beginning of said zone at a point proximate to said yarn entrance and continues along said path coaxially for a distance of at least three inches (7.62 cm.) upstream therefrom.

The invention is particularly effective and economical when a single jet of compressible fluid having a cross-sectional area less than that of the yarn passageway is perpendicularly impinged in said passageway on said yarn or yarns, and particularly at yarn speeds above about 1500 ypm (1371 mpm).

The process is particularly effective and useful for combining a plurality of non-coherent or less coherent yarns into a single more coherent yarn of greater denier, i.e., doubling. A preferred application of such a process is for combining bulked yarns which are differentially dyeable with respect to one another for making mixed-colored yarns, such as marl or heather yarns, of almost any degree ranging from very bold to very fine. To make bulked heather yarns having a high degree of intermingling, it is preferred that the yarns entering the intermingling zone have a Coherency Factor of less than 6.0. Supply yarns with higher coherency result in less intermingling and bolder mixed-color effects.

The process is satisfactorily operable and advantageous using tubular confinement upstream of the intermingling zone for a distance of three inches (7.62 cm.) or more. More satisfactory results and more uniform yarns can be obtained with a confinement distance of at least five inches (12.7 cm.). Even ( - 6 - ( better operability and yarn appearance have been obtained when the tubular confinement is continued upstream from the intermingling zone for a distance of at least 10 inches (25.4 cm.).

To facilitate filament intermingling it is preferred that the yarn be withdrawn from said zone at a speed that is from 2 to 15% less than the speed at which it is forwarded to said zone, preferably from 5 to 15% when bulked yarns are fed directly from a zone in which the filaments of the supply yarn or yarns are disentangled by tensioning.

Under certain circumstances, operability and yarn appearance can be improved by also peripherally constraining lateral vibrations.in the treated yarn, as it is withdrawn from the intermingling zone (i.e., by tubular confinement downstream from said zone in a manner comparable to the upstream tubular confinement). This additional confinement is applicable, for example, to supply yarns which have been dyed and consequently contain less than about 0.3% by weight of a yarn finish.

This invention also provides an improved apparatus for intermingling filaments of a continuous multifilament yarn or yarns which includes a fluid-jet filament intermingling body member,a yarn passageway, which preferably is substantially cylindrical in form through said body member having a yarn entrance end and a yarn exit end, at least one fluid conduit leading into said passageway through said body member having an axis which intersects the longitudinal axis of said passageway, means for supplying compressible fluid under high pressure to said conduit, means for forwarding a yarn or yarns at a controlled speed to the entrance end of said passageway, means for - 7 ( withdrawing intermingled yarn from said yarn exit end, a yarn guide positioned between said means for forwarding yarn and said yarn entrance end which guide defines a straight yarn path between said -guide and said yarn entrance end which path is coaxial with said passageway wherein the improvement comprises said guide consisting essentially of a tube having a longitudinal bore substantially coaxially aligned with said passageway and positioned along a straight line path between said means for forwarding yarn and said passageway entrance end, said bore having a diameter less than the diameter of said passageway but large enough to allow free passage of said yarn or yarns through said bore while peripherally constraining lateral filament vibrations and lateral yarn movement in said bore, said bore having an exit end located proximate to said yarn passageway entrance end and having a substantial length, i.e. at least 3 inches (7.62 cm.).

The bore preferably has a length of at least 5 inches (12.7 cm.) and more preferably at least 10 inches (25.4 cm.) in accordance with the above described process.

Normally the ratio of the diameter of said passageway to said bore should be at least about 1.3:1.0, preferably no greater than about 4.0:1.0.

The apparatus is particularly effective when the exit end of the upstream tube is spaced from the entrance end of said passageway within the range of about 0.125 to 0.50 inches (0.32 to 1.27 cm.).

For bulked yarns of conventional carpet deniers, i.e., 1,000 to 15,000 denier, effective bore diameters for the tube are within the range of about 0.06 to 0.25 inch (1.52 to 6.35 mm.). .51838 The apparatus can include a guide tube of comparable dimensions and relative spacing positioned between said yarn passageway exit end and said withdrawing means coaxially along said yarn path·.

Applying water to the yarn prior to intermingling improves operability and the intermingling effectiveness of the process. Water application devices are known in the art for such purposes. The water should be applied at a rate to provide from about 5 to about 25 percent by weight of the yarn, but the amount is not critical.

Regarding the Figures in greater detail, FIG. 1 depicts an apparatus of the invention being used to combine three bulked multifilament supply yarns into a single coherent bulked heather-dyeable yarn. The apparatus includes a machine face plate 10 on which are mounted a yarn guide 12 followed by a water application device 14, change of direction roll 16, a means for forwarding yarn consisting of a pair 20 of driven rolls, roll 18 and its associated canted roll 20. Then upstream tube guide 30 and optional downstream tube guide 36 (bores thereof not shown) are held in coaxial alignment, by brackets 32 and 38 respectively, with cylindrical yarn passageway 33 in 25 jet body member 34. Body member 34 is shown in cross-section to reveal passageway 33 which is perpendicularly intersected by smaller fluid conduit . Fluid conduit 35 is supplied with a compressible fluid under pressure from a source (not shown). The 20 space between tube guides 30 and 36 determines the length of the intermingling zone produced by the action of the fluid jet device. Means for withdrawing the intermingled yarn from the intermingling zone consists of take-away idler roll - 9 ( 40. Roll 40 le followed by a coner roll (not Bhown) or other suitable roll and windup arrangement. Roll 40 is held in position by bracket 42 so as to define a straight yarn path from roll 18 to roll 40 which is coaxial with tubes 30, 36 and with passageway 33.

As shown in FIG. 1, differentially-dyeable, bulked, multifilament supply yarns 50, 52, 54 from separate packages held on a creel (not shown) are pulled by rolls, 18, 20 through guide 12 and water application device 14, around roll 16, and then are forwarded in a converged contiguous state into the upstream end of tube 30, through body member 34 and tube guide 36. They are withdrawn by take-away roll 40 as an intermingled heather-dyeable coherent bulked yarn 58.

The apparatus depicted in FIG. 2 is the same as that in FIG. 1 but modified by the deletion of’ optional downstream tube guide 36 and by the addition of driven tensioning roll 24 and its associated canted roll 22 along with parallel snubbing pins 28 mounted in a base 26 for disentangling filaments of the supply yarns prior to being intermingled.

The tubular guides stabilize the yarn apparently thus allowing more efficient intermingling by the jet in the intermingling zone. Also the formation of single filament loops caused when out-of-position filaments are locked in place by the entangling action are minimized. If desired, the entrance to the yarn passageway can be constricted slightly, for example either by an eccentric yarn gate of the type shown in Fig. 2 of U.S. patent 4,059,873 (Nelson) or by a concentric constriction such as a smaller diameter hole in a metal plate - 10 f placed against the entrance to the yarn passageway; but such constriction tends to reduce the effectiveness of the intermingling zone resulting in less entanglement in the nodal regions, where 5 entanglement is more than adequate, such a constriction can be used to provide a slight jet forwarding action to the yarn as it exits the intermingling zone or to make a more uniform less nodal structure along the yarn.

Supply yarns for use in this invention can be compact or bulked. Bulked supply yarns are preferably those which have been bulked by a hot fluid jet-bulking process, for example of the type described in U.S.P. 3,781,949 (Breen et al.). Such yarns have superior bulk and normally have some coherency due to intermingling of the filaments; but this intermingling is usually only among a part of the filaments at any location along the yarn and seldomly among all filaments at a given location.

Therefore when two or more of these yarns are combined by this invention without first removing this intermingling, the filament bundles open to a limited extent so that the filaments of different yarns can intermingle to some degree; but if the resulting yarn is then cross-dyed, the yarn will appear mostly as a bold mixture of the individual yarn colors with little blending of colors. When this coherency is removed by tensioning and snubbing the supply yarns before being intermingled together, the filaments of the yarns are then able to open and intermingle more freely and frequently, producing more zones of blended colors.

The term bulked as used herein refers to yarns of permanently crimped filaments, that is the - 11 ( filaments retain their crimp upon removal from the yarn.

The term differentially dyeable refers to yarns which can be cross-dyed in a common dye bath to different colors or shades of color. The term also includes differentially colored yarns since such yarns upon dyeing, even with a common dye, will inherently remain differentially dyed, i.e., differently colored.

The Coherency Factor test of filament intermingling in a yarn used herein is determined in the known way by clamping a sample of yarn in a vertical position under the tension provided by a weight in grams which is 0.20 times the yarn denier but not greater than 100 grains. A weighted hook, having a total weight in grams numerically equal to the average denier per filament of the yarn but weighing no more than 10 grams, is inserted through the yarn bundle and lowered at a rate of 1 to 2 cm./sec. until the weight of the hook is supported by the yarn. The distance which the hook has travelled along the yarn until the weight is supported characterizes the extent of filament intermingling in the yarn. The result is expressed as a Coherency Factor which is defined as 100 divided by the above travelled distance in centimeters. Since filament intermingling is random, a sufficiently large number of samples are tested to define a representative average value for the test yarn.

For more highly intermingled heavy denier yarns, such as carpet yarns produced by this invention, the Lateral Pull-apart Test provides a more discriminating measure of yarn coherency. For ( this known test, two hooks are placed at a randomly selected point in about the center of the sample yarn bundle to separate it into two groups of filaments.

The hooks are pulled apart at a rate of 5 inches per minute (12.7 cm. per minute) at a 90® angle to the yarn axis by a tensile testing machine which measures the resistance to separation of the hooks, such as an Instron machine* The yarn is pulled by the hooks until a 1-lb (454 gm.) force is exerted, at which point the machine is stopped and the distance between the two hooks is measured and recorded. Ten determinations are made for each yarn and the average taken as the pull-apart value. The test yarn sample length should be at least 4-6 inches (10-15 cm.) long and selected randomly from throughout the yarn package to be tested.

*Instron is a registered Trade Mark.

Exanple 1 This example demonstrates the significance of tube guides in the apparatus and process of the invention using bulked supply yarns already having a moderate amount of filament intermingling (yarn coherency) as commonly provided in bulked continuous filament nylon yarns intended for commercial use as direct-tufting carpet yarns. Such yarns commonly have a Coherency Factor in the range of from about 25 to about 50.

The apparatus and process correspond to those described in FIG. 1.

The jet device body member has a yarn passageway 1.000 + 0.001 inch (2.540 cm.) long with a constant diameter of 0.228 + 0.001 inch (0.58 cm.) which is perpendicularly intersected at its mid-point by a cylindrical fluid conduit with a diameter of 0.125 + 0.001 inch (0.32 cm.). The center line of - 13 ( the conduit intersects within 0.001 inch (0.00254 cm.) of the center line of the passageway.

The edges of the yarn entrance and exit ends of the passageway are smoothed by rounding to a 0.03 inch (0.76 mm.) radius.

The jet device is manufactured from a Type 416 stainless steel block which is 1.500 inches wide (3.81 cm.) by 1.000 inch high (2.540 cm.) by 1.125 inch deep (2.86 cm.}. The passageway runs through the block perpendicularly from top to bottom and is centered between each end thereof. Its center line is positioned 0.500 inch (1.27 cm.) from the front of the block and the conduit enters from the rear of the block. The body member is adapted to be bolted to a manifold for supplying the conduit with air under pressure.

The conduit is supplied with air at 150 psig (10.5 kg/cm.2) which flows through it at a rate of 36 scfm (1.02 cu. meters/min) at ambient temperature.

Forwarding rolls 18, 20 operate to supply the yarns at 1,000 ypm (914 meter/m.). The yarns make at least eight yarn wraps around the rolls to assure a consistent feed rate. Hater is applied by the water application device 14 to the yarns at 1.0 gal./hr. (3.79 liter/hr.). The speed of a take-up coner roll is adjusted to provide a 3% yarn overfeed to it from the forwarding rolls.

A piece of commercial seamless stainless steel tubing with a bore diameter of 0.084 inch (2.13 mm.) and 11.0 inch (27.9 cm.) long, for peripherally constraining lateral vibrations in the yarn upstream of the jet, is coaxially aligned with the yarn passageway and positioned with a 1/4 inch (0.64 cm.) clearance between its exit end and the ( entrance to fhe yarn passageway. The entrance end of the tube is about 5.5 inches (13.97 cm.) from where the supply yarns leave the surface of the forwarding roll on their way to the jet device.

Runs are made using this apparatus with three supply yarns for each of the following items: (A) The supply yarns are each 1225 denier.

They are commercial (Du Pont) nylon bulked continuous filament yarns prepared by a hot fluid jet screen-bulking process. The yarns are differentially dyeable - one being cationically dyeable (Type 854), one light-acid dyeable (Type 855), and one being deep acid dyeable (Type 857). The yarns contain a conventional producer spin finish within the standards of 0.7% mean finish on yarn and package limits within the range of 0.4 to 1.35% finish on yarn.

The three yarns are made into a single coherent yarn under the above conditions. Visual examination of cross-dyed skeins shows a periodic nodal interlace structure with a sizable amount of filament intermingling (in spite of the intermingling already present in each of the supply yarns). The yarn gives a pull-apart value of about 1.25 in. (3.18 cm.).

Another yarn is prepared from the same three supply yarns under fhe same conditions but with the addition of a tube guide of the same dimensions as above coaxially aligned downstream of the jet yarn passageway with a 1/4 in. (0.64 cm.) clearance between the passageway exit and the entrance to the downstream guide tube. Visual examination of cross-dyed skeins of the resulting yarn as well as pull-apart coherency values show that the yarn is - 15 - ( substantially the same as when made without the downstream tube.

(B) Using the same process conditions as in (A) three ends of space-dyed 1820T-497 bulked continuous filament nylon yarn are entangled to make a single coherent yarn. The yarns have been randomly space-dyed which provides a mottled beige/brown appearance on the wound supply packages. Because of the dyeing, producer spin finish on the yarn has been reduced to about 0.25% by weight. Yarn made using both upstream and downstream tube guides as above shows a desirable periodic interlace structure regularly along the yarn resulting in a pull-apart value of 1.6 in. (4.06 cm.). Under the same conditions except with no water applied to the yarn only a low level of intermingling is realized which is not subject to meaningful pull-apart testing. A third test is made using the upstream tube guide only, with water application. The resulting yarn shows a less desirable nodal interlace structure randomly spaced along the yarn with an average pull-apart value of 2.3 in. (5.84 cm.). From this it is concluded that for entangling supply yarns having low yarn finish levels, such as 0.3%, best results are obtained with water applied and using tube guides both upstream and downstream of the jet device.

Example 2 This example shows the effectiveness of tube guides with the same supply yarns and conditions as in Example IA except that the moderate coherency in the supply yarns (C.F. 25-50) is first removed from each yarn to provide a Coherency Factor of less than 6.0. This is achieved by disentangling the filaments under tension with the aid of a series of parallel - 16 f ( snubbing pins using apparatus as represented in FIG. 2. Four steel snubbing pins 0.25 in. (6.35 nun.) in diameter are used. They are spaced with their centers about 0.5 in. (1.27 cm.) apart. The speed of the tension rolls (24, 22) is adjusted to provide a tension on the yarns between them and the forwarding rolls of about 1.2 gpd. Use of these low cohesion supply yarns allows the overfeed to be increased to 10% between the forwarding rolls and the take-away roll. Cross-dyed skeins of yarn produced in this manner show a desirable regular periodic interlace node structure separated by sections of highly blended filaments. A pull-apart test gives the value of 0.9 in. (2.29 cm.).

This process is repeated under the same conditions except that no water is applied to the yarn with the water applicator. The product again is a highly blended, highly entangled yarn with a pull-apart of 1.0 in. (2.54 cm.), but the periodic highly entangled regions are less dense than before. Therefore, under these conditions water application is not reguired to obtain a good product.

The process (using water) is repeated except that the speed of the supply yarn is increased to 2,000 ypm (1,828 mpm) and the overfeed is increased to 12%. Cross-dyed skeins of yarn prepared in this manner show a marked difference in entanglement structure as compared to that produced at the lower speed. The periodic nodal interlace structure of the lower speed yarn is replaced by a randomly blended filament bundle character of more uniform density along the yarn. The level of filament blending is very good considering the high yarn speed and relatively low flow of air in the jet (36 scfm, 1.02 cu.meters/min.). The abbreviation scfm employed herein stands for standard cubic feet per minute. - 17 ( From these tests it is concluded that standard commercial bulked continuous filament supply yarns containing normal amounts of spin finish (i.e., at least about 0.75%) require only an upstream guide tube for effective operation.

Similar results are obtained in a test series using guide tube bore diameters of 0.060 in. (1.52 mm.), 0.120 in. (3.05 mm.) and 0.152 in. (3.86 rom.) in lengths of 6 in. (15.24 cm.) and 11 in. (27.94 cm.). Little difference in color blending and entanglement level is found throughout the series. A 1/4 in. (6.35 mm.) clearance between the guide tube end and the entrance to the yarn passageway is maintained for each tube size. Conditions were otherwise held substantially constant.

Example 3 This example substantially repeats the first run of Example 2 under the following conditions. The supply yarns are the same and the apparatus is again as represented in FIG. 2. The forwarding roll speed is 1119 ypm (1023 mpm). The supply yarns are disentangled to a Coherency Factor of less than 6.0 under a tension of 1.14 gpd. A single guide tube is used upstream of the jet having a length of 11 in. (27.94 cm.) with a bore diameter of 0.152 in. (3.86 mm.). Its downstream end is spaced 1/4 in. (6.35 mm.) from the yarn passageway entrance. The jet is of the same design as in Example 2 except that the diameter of the fluid conduit is 0.156 in. (3.96 mm.). The fluid conduit is supplied with air at a pressure of 75 psig at 25eC which provides a flow rate of 23 scfm (0.64 m /min.). A 3-slot water applicator is used at a flow rate of 1.0 gal/per (3.79 liters/hr.). A coner roll controls the SI 9 38 - 18 take-away speed at 1,007 ypm (920 mpm) giving an overfeed of 11%. The coherent yarn product is wound into a package under a winding tension of 225 grams. These conditions provide a product throughput of 56 lbs/position/hr. (25.4 kilograms).

In spite of the lower air pressure used in this process versus Example 2, dyed knit fabric of the yarn shows the yarn to be more highly blended than a control yarn prepared under similar conditions but at a much higher air pressure and flow using the process and apparatus of D.S.P. 4,059,873.

Example 4 This example demonstrates the effects of guide tube length on the operating performance and yarn appearance under the process conditions of Example 3.

Identical runs are made except that tubes are tested having lengths of 1 inch (2.54 cm.), 3 inches (7.62 cm.), 5 inches (12.7 cm.), and 11 inches (27.94 cm.) as well as a textile yarn guide 1/4 inch (0.64 cm.) long and no guide at all between the forwarding rolls and the yarn passageway.

Operating performance is best for the 11 inch (27.94 cm.) tube. Yarns entering the shorter tubes show an unstable vibratory action which is particularly noticeable with the 3 inch (7.62 cm.) and 5 inch (12.7 cm.) tubes.

Cross-dyed skeins of the yarns are evaluated for appearance. A tube length of at least 3 inches (7.62 cm.) is seen reguired to produce a uniform, well-intermingled yarn. Shorter tubes as well as no tube produce yarns with less intermingling and a less uniform distribution of nodes.

Based on both operating performance and yarn appearance, the preferred tube length is concluded to be at least 5 inches (12.7 cm.).

Example 5 This example demonstrates the use of the invention to make a very high denier heather yarn for carpets.

The apparatus is as shown in FIG. 2 using the snub pins to disentangle the supply yarns to a Coherency Factor of less than 6.0. Three types of commercial hot fluid jet bulked continuous filament 66-nylon yarns are combined into a single yarn using two ends of each yarn type (six yarns in all). The types are a cationic 1225 denier (Type 494) mid-dull yarn, a 1225 denier light acid dyeable (Type 495) mid-dull yarn and a 2470 denier deep acid dyeable (Type 497A) mid-dull yarn. The jet body construction is as in the preceding examples except the diameter of the passageway is 0.312 inch (0.79 cm.) and the air conduit has a diameter of 0.213 inch (0.54 cm.). The conduit is supplied with air at 100 psig (7 kg./cm ) at a flow rate of 40 scfm (1.12 m.3/min.). The forwarding speed is 455 ypm (416 mpm) and water is applied at a flow rate of 2.0 gal./hr. (7.57 liters/hr.). The single upstream guide tube is 11 inches (27.94 cm.) long with a bore 0.152 in. (0.39 cm.) in diameter. Its exit end is spaced 1/4 in. (0.64 cm.) from the passageway entrance. The yarn withdrawal speed is controlled by a coner roll at 412 ypm (377 mpm) to give an overfeed of 10*. The resulting yarn has a total denier of 10400 and a periodic nodal interlace structure with a sizable amount of filament intermingling among the component yarns. A cross-dyed carpet of the yarn has - 20 a nondirectional heather appearance with the deep-dyed component yarn predominating.

Example 6 This example demonstrates use of the 5 invention for doubling compact (non-bulked) yarns to make a coherent compact yarn of heavier denier.

The supply yarns consist of three ends of a drawn 1,000 denier 68 filament zero-twist flat 66-nylon yarn which has not been interlaced and is substantially free of filament entanglement. The yarn contains 0.8S of a conventional yarn finish.

The apparatus is fhe same as in Example 3 except that the tensioning rolls and snub pins are not used since the supply yarns are already substantially free of filament entanglement.

The compressible.-fluid is air at 100 psig (7 kg./cm.2) and the flow rate is 30 scfm (0.84 m.3Ain.). A winding tension of .200 grams is used and the resulting yarns have a denier of about 3100.

Suns are made at two different overfeeds, each with and without the single tube guide preceding the intermingling zone, otherwise the same as in The process conditions are Example 3. The results are 25 as follows: With Tube Without Tube % Overfeed 2.1 7.6 2.1 7.2 Pull Apart, In. 1.40 1.23 2.33 2.82 (cm.) (3.56) (3.12) (5.92) (7.16) 30 Xt is apparent from these > results that the tube guide significantly improves the*filament entangling effectiveness of fhe intermingling zone.

Claims (10)

1. An improved process for intermingling filaments ( of a continuous multifilament yam or yarns by forwarding the yarn or yams through a fluid-jet filament intermingling zone which includes an enclosed yam passageway with a yam entrance and a yarn exit, and in said passageway impinging at least one high velocity jet of compressible fluid upon said yam or yams to vibrate and to intermingle filaments thereof while preventing lateral filament vibrations in the yarn or yams upstream of said zone wherein the improvement comprises forwarding and withdrawing said yam or yams to and from said zone along a path which is substantially coaxial with said passageway and peripherally constraining lateral filament vibrations in said yam or yams immediately upstream of said zone by tubular confinement which extends from the beginning of said zone at a point proximate to said yam entrance and continues along said path . coaxially for a distance of at least three inches upstream therefrom.

2. A process of claim 1 wherein said passageway has a substantially cylindrical form.

3. A process of claim 1 or 2 wherein a single jet of compressible fluid is impinged on said yarn or yams in said passageway from a direction perpendicular to the longitudinal axis of said passageway.

4. A process of claim 3, wherein a plurality of yams are forwarded into said passageway. 5. Bore is at least about 1.3:1.0. 21. An apparatus of claim 20 wherein the exit end of said bore is spaced from the entrance end of said passageway within the range of about 0.125 to 0.5 inches. 10 22. An apparatus of claim 20 wherein said bore diameter is within the range of about 0.060 to 0.250 inch. 23. An apparatus of claim 15 or 16 wherein said means for forwarding a yam or yarns operates at a 15 forwarding speed of at least 1500y?m. — 24. An apparatus of claim 17,18 or 19 wherein said means for withdrawing yarn operates at a speed from 2 to 15% less than the speed of said forwarding means. 20 25. An apparatus of claim 17 wherein said means for forwarding yarn, said bore, said passageway and said means for withdrawing yam define a continuous straight yam path between said forwarding and said withdrawing means. 25 26. An apparatus of claim 25 including a second tube for guiding yam positioned along said yarn path between said passageway exit end and said means for withdrawing yam, said second tube also having a bore coaxial with said passageway and with said 30 yam path, said bore having a diameter less than the diameter of said passageway but sufficient to allow free passage of said bulked intermingled yarn while peripherally constraining lateral yarn and filament movement therein and having a yarn entry 35 end positioned proximate to said passageway exit. - 25 27. An apparatus of claim 26 wherein said means for withdrawing yarn operates at a speed from 2 to 15% less than the speed of the forwarding means. 28. A process as in claim 1 substantially as described 5 in any of the foregoing Examples. 29. An apparatus as in claim 15 substantially as described with reference to either Figure of the accompanying drawings. 30. A yarn obtained by a process as claimed in any of claims 1 to 14, or claim 28, or by means of an apparatus 5 supplying compressible fluid under high pressure to said conduit, means for forwarding a yam or yams at a controlled speed to the entrance of said passageway, means for withdrawing intermingled yam from said yam exit end, a yam guide positioned between 10 said means for forwarding yarn and said yarn entrance end which guide defines a straight yam path between said yarn forwarding means and said yam entrance ~ end which path is coaxial with said passageway wherein the improvement comprises said guide consisting essen15 tially of a : tube having a longitudinal bore substantially coaxially aligned with said passageway and positioned along a straight line path between said means for forwarding yam and said yam entrance end, said bore having a diameter substantially less 20 than the diameter of said passageway but large enough to allow free passage of said yam or yarns through said bore while peripherally constraining lateral filament vibrations and'lateral yam movement in said bore, said bore having an exit end located proximate 25 to said passageway entrance end and having a length of at least 3 inches (7.62 cm). 16. An apparatus of claim 15 wherein said passageway is substantially cylindrical in form. 17. An apparatus of claim 15 or 16 having a single 30 fluid conduit which intersects said passageway perpendicularly and which has a cross-sectional area substantially less than that of said passageway. 18. An apparatus of claim 17, wherein said bore is at least 5 inches long. 51838 19. An apparatus of claim 17 wherein said bore is at least 10 inches long. 20. An apparatus of claim 18 or 19 wherein the ratio of the diameter of said passageway to said

5. A process of claim 4 wherein at least 2 yarns of said plurality are differentially dyeable with respect to one another. - 22 6. A process of claim 4 wherein at least one yam of said plurality has been space dyed and is a bulked yarn.

6.0 when forwarded into said passageway. 10. A process of claim 1,2,3,4 or 5 wherein said yams are forwarded into said passageway at a speed of at leat 1500 ypm. 11. A process of claim 3,4,5,8 or 9 wherein a coherent yarn is withdrawn from said zone at a speed that is from 2 to 15% less than the speed at which it is forwarded to said zone. 12. A process of claim 3,4, or 5 wherein lateral filament vibrations in the intermingled yarn downstream from the exit of said passageway are peripherally constrained by tubular confinement from a point proximate to said exit and continuing for a substantial distance downstream therefrom. 13. A process of claim 12 wherein the intermingled yarn is withdrawn from said zone at a speed that is from 2 to 15% less than the speed at which It is forwarded to said zone. 14. A process of claim 4,5 or 9 wherein at least one of said yarn or yams is a bulked yarn. 15. An improved apparatus for intermingling filaments of a continuous multifilament yarn or yams which includes a fluid-jet filament intermingling body member, a yarn passageway through said body member - 23 having a yarn entrance end and a yarn exit end, at r least one fluid conduit leading into aaid passageway through said body member having an axis which intersects the longitudinal axis of said passageway, means for

7. A process of claim 4 or 5 wherein the tubular confinement is continued from said point for a distance of at least 5 inches upstream therefrom.

8. A process of claim 4 or 5 wherein the tubular confinement is continued upstream from said point for a distance of at least 10 inches.

9. A process of claim 5 wherein said differentially dyeable yarns have a Coherency Factor of less than

10. As claimed in any of claims 15 to 27, or claim 29.