CA1056146A - Fluid process for making continuous filament heather yarn - Google Patents

Abstract

ABSTRACT
A twist-free continuous filament heather yarn of reduced streakiness and chevroning and muted appearance of the colors of the yarn making up the heather yarn when formed into a fabric is prepared by tensioning a plurality of twist-free crimped continuous filament yarns having a different color and/or dye receptivity in order to remove intra-yarn entanglement, passing the tensioned yarns side-by-side into a jet intermingling zone at a slower withdrawal rate from said zone than feed rate to said zone. The fila-ments of each yarn making up the heather yarn are randomly entangled from yarn-to-yarn within the jet intermingling zone to form a heather yarn.

Description

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This invention relates to a heather yarn made of bulked continuous filament yarns having different color and/
or dye receptivity and to a process for makiny such heather yarn.
A co~tinuous filament heather yarn is a yarn con-sistiTlg of a multiplicity of continuous filaments which are either of different color and/or have a different dye recep-tivity so that they are capable of being dyed to different colors. The effect of the heather yarn when colored and incorporated into a pile fabric is to display the color of the filaments primarily at the tip of the loop in the pile whether the loop is intact or is cut. The color of the pile fabric then takes on the appearance of the colors appearing at the top of each loop of the heather yarn making up the fabric~ Continuous filament heather yarns have suffered from the disadvantage that the color present at the top of the loops can be either (a) the same or very similar color, whereby the pile fabric has the appearance of being made from a single colored yarn as a result of too complete blending of the different colored filament, or (b) too contrasty, i.e.~ too bold or flashy, which means it is predominantly the colors of the yarns making up the heather yarn that is seen at the tip of the loop in the pile fabric, to give the pile fabric a salt and pepper appearance. Obtaining and controlling the desired balance of heather during yarn manufacture is difficult.
South African Patent Publication 73/3977 dis-closes a process wherein the con~inuous filament heather yarn is made by both drawiny and crimping the componen~
yarns together, ~ollowed by a pair of intermingling steps.

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In the first intermingling step, the filaments are inter-mingled within each yarn, and in the second step the two intermingled yarns are brought together for entanglement with one another. In each intermingling step the yarn is under tension. In terms of heather, the result of this process is a heather yarn which is bold, because the inter-mingling of the filaments within each feed yarn limits blending of the yarns together.
U.S.Patent 3,811,263 discloses the making of a heather yarn from a plurality of differently colored yarns ~y intermingling under tension controlled, fluid ~-et condi-tions which also limits blending. The heather yarn of the present invention provides not only the colors of the component yarns but also provides various blends of such colors, with the areas of these different colors being randomly interspersed along the yarn whereby a pile fabric prepared therefxom has the appearance of individual color "points", which are the component yarn colors, dispersed in a heathered background which mutes the color l'points"
and consists of various colors arising from various degrees of ~lending of the component yarns making up the heather yarn. More specifically, the continuous filament heather yarn of the present invention is composed of a plurality of crimped continuous filament yarns of different color and/or dye receptivity and substantially freP of twist, said crimped continuous filament yarns in said heather yarn being substantially free of twist relative to each other, each said crimped continuous filament yarn in said heather yarn comprising a plurality of continuous fila-ments which are yarn-to-yarn randomly interminaled to form ~ 5~14~
yarn-to-yarn blended areas of random length of said fila-ments randomly interspersed between yarn-to-yarn unblended areas of random length of said filaments. The yarn-to-yarn blended areas hold the crimped continuous filament yarns ~oge~her to form the heather yarn, and the distribu-tion of ~hese areas among the unblended areas as well as the lengths and proportions of the latter enables the heather yarn of the present invention to be made into a pile fabric which is substantially free of noticeable streaks and chev-rons, and which is characterized by the colors of saidcrimped continuous filament yarns being visible but muted in appearance in said pile fabric.
The continuous filament heather yarn of the present invention is made by the process comprising ten-sioning a plurality of crimped continuous filament yarns of different color and/or dye receptivity and having a total denier of at least 400 to straighten the crimp of the filaments within each said yarns, feeding the yarns under tension and in contiguous relationship into a jet inter-mingling zone with a slower withdrawal rate from said zonethan feed rate to said zone, and randomly jet intermingling the filaments of said yarns from yarn-to-yarn within said jet intermingling zone while free of tension.
More specifically, the invention is a process for making a continuous-filament heather yarn wherein a plurality of crimped continuous-filament yarns of different color and/or dye receptivity having a total denier of at least 400 are tensioned to substantially straighten the filaments, followed by randomly entangling the yarns together with a fluid jet in a jet-intermingling zone ~C~56~4~i characterized in that a tension from 0.5 to 1.25 grams per denier is exer-ted to disentangle and parallelize the ila-ments prior to the intermingling, the yarns are ed to the jet intermingling zone substantially free of entanglement, the Eluid jet serves to forward the combined yarns, and the heather yarn is withdrawn from the jet-intermingling zone at a slower rate than the feed rate to the zone such that the yarns are free of tension during intermingling.
Fig. 1 is a schematic elevational view of an apparatus arrangement suitable for the process of the pre-sent invention~
Fig. 2 is a perspective cut~away view of one embodiment of jet intermingling device used in the process of the present invention.
In Fig. 1 are shown three bobbins, 2, 4, and 6, supplying crimped continuous filament yarns 8, 10 and 12 which have different color and/or dye receptivity through a convergence guide 11 and then to a pair of draw rolls 14 and 18 and associated separator rolls 16 and 20. The yarns 8, 10 and 12 are supplied side-by-side to draw roll 14, whereupon the yar~s wind first around draw roll 14 and separator roll 16 in side-by-side relationship and then around draw roll 18 and separator roll 20 for a sufficient number of wraps in side-by side relationship that there is no slippage of the yarns on the roll surfaces. Draw roll 18 and separator roll 20 are operated at a faster surface speed than that of draw roll 14 and separator roll 16 so that the continuous filaments of each of the yarns 8, 10 and 12 are tensioned in passing from roll 14 to roll 18~
This tensioning o the yarns '!straightens-out! the crimp 1~56~4~ii in the feed yarns 8, 10 and 12 which has the effect of parallelizincJ the filaments of the yarns and removing entanglemen-t between the filaments within each yarn. The draw roll 18 and separator roll 20 do not operate at such a high relative speed over draw roll 1~ and separator roll 16 as to effect drawing of the continuous filaments of the ya~ns because this would defeat the purpose of the filament cximp present in the feed yarns 8, 10 and 12.
Between draw rolls 14 and 16 is a snubbing device 22 consisting of a line of snubbing pins 24 through which the yarns 8, 10 and 12 interweave so as to further dis-entangle the continuous filaments of each of the yarns.
Fig. 1 shows the individuality of each of the yarns 8, 10 and 12 as they pass through the snubbing device 22. Ideally, it is desired that each of the continuous filaments of each of these yarns also possesses this individuality, i.e., parallelism and disentangled relationship with adjacent filaments, as the yarns pass through the snubbing device.
This parallelized relationship remains for the yarns in filaments thereof as they pass around the draw roll 18 and separator roll 20.
From draw roll 18, the yarns 8, 10 and 12 in side-by-side parallel relationship pass through a water applicator such as water sprays supplied by nozzles 2~
which wets the filaments of the yarns for treatment in the subsequent jet intermingling zone 28 which will be described in greater detail hereinafter t and finally the heather yarn 29 formed by the intermingled yarns is wound up on roll 30O
In the jet-intermingling zone 28, the continuous ~ S~ ~6 filaments are yarn-to-yarn randomly jet-intermingled to form yarn-to-yarn blended areas o~ random length of the filaments randomly interspersed be-tween yarn-to-yarn unblended areas of random length of the ilaments, these ar~as beincJ so proportioned that pile fabrics formed from the ~arn are ree from noticeable streaks or chevrons and present a pleasing coloration (when the yarns are dyed i not already colored) consisting of the colors of the individual yarns muted in a background o blends of the colors.
The jet intermingling zone 28 is shown in greater detail in Fig. 2. The zone 28 comprises a jet body 31, through which is ormed a yarn passageway 32 and a fluid passageway 34 extending perpendicularly from the yarn pass-ageway 32 to the exterior of the jet body. A yarn gate 36 is positioned covering the portion of the entry side of the yarn passageway 32, the gate 36 having a smooth sur-face over which rides the parallelized yarns 8, 10 and 12 entering the jet body in contiguous relationship. The gate 36 also has a curved surface 38 which smoothly leads the yarns 8, 10 and 12 into the yarn passageway~
Within the yarn passageway, a pressurized fluid jet at about ambient temperature and of sufficient force is applied through the, and preferably only, fluid passage-way 34 to provide the random intermingling of yarns 8, 10 and 12 just described. The restriction of the entrance to the yarn passageway by gate 36 has the effect that the ~luid supplied by orifice 34 which intermingles the ~ila-ments of the yarns 8, 10 and 12 also primarily exits the yarn passageway through the opposite side of the jet body.

~1(315~;~4~ci The effect of this concurrent flow of fluid with the move-ment of yarn within the yarn passageway is that the ~luid also serves to Eorward the yarns from draw roll 18 and main~
tain the yarns under tension up until the time of jet inter-~in~ling. The intermingled heather yarn 29 just exiting th~ jet body as shown in Fig. 2 forms a "rooster tail"
relative to the jet body 31. The "rooster tail" is a region in which the filaments of the yarns are still splayed from the pressurized fluid jet, whereby intermingling is still occurring. The heather yarn 29 is also traveling at a slower speed than the yarns 8, 10 and 12 entering the jet-intermingling zone and is taken up by windup roll 30. It is critical in the process of the present invention that the surface speed of windup roll 30 be less than the sur-face speed of draw roll 18, whereby the yarns 8, 10 and 12 are free of tension during jet intermingling, otherwise the desired random intermingling of filaments will not occur and the results will be a heather yarn that is too bold.
The number of feed yarns can vary from the three yarns shown in Fig. l; at least two crimped continuous filament yarns are required, but a greater number such as four or moxe crimped continuous filament yarns can be used.
The crimped continuous filament feed yarns can be made of continuous filament yarns processed by any of the well-known crimping methods to produce a crimp in the yarn, such as gear crimping, stuffer box crimping, and hot jet crimping which is preferred and produces random curvilinear crimp in the yarn. The yarns are preferably heat set.
Alternatively, the feed yarn can be crimped by being of bicomponent filaments which supply the crimp by differential : ~ ;

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shrinkage. In any event, the crimp-forming process, partic-ularly in the case of hot jet and stuffer box crimping of the eeed yarn, also en-tangles the filaments within each ~arn. This entanglement must be removed, otherwise the desired yarn-to-yarn filament blending does not occur in the interm~ngling zone 28. This entanglement is removed by tensioning (not drawing) the feed yarns with or without the help of a snubbing device.
Examples of suitable bulked continuous filament yarns are those described in Example XXII of Breen et al., U.S. Pat. 3,186,155. Preferably, each of the feed yarns used in the present invention is characterized by the same ~ind of crimp. Also, preferably, the filaments of each feed yarn has at least 4 crimps per 2.54 cm as determined by the test method disclosed in Horn and Nelson U~S.Pat. 3r611,698. The crimp of the feed yarn supplies high bulk to the heather yarn of the present invention.
The total denier of the feed yarns is at least 400 since the heather yarns of the present invention are primarily intended for use in tufted and woven constructions as characterized by upholstery and carpet constructions, Generally the denier per filament of each yarn will be within the range of from 4 to 25. The proportion of each yarn fed to the process for making a heather yarn of the present invention can be changed depending on the heather result desired.
While no drawing of the yarns occurs between draw rolls 14 and 18, the greater surface speed of draw roll 18 over draw roll 14 does e~ert tension on the yarns which effects the disentanglement and parallelizing _ g _.

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hereinbefore described. Generally, the degree o~ tenslon exerted will be ~rom 0~5 to 1.25 gram~ per denler, prefer-ably 0~75 to 1.1. Other methods o~ tensionlng the fead y~rn~ ~uch as the use of sp~ced pairs o~ pinch rolls~
c~n be u~ed.
The de~ree of snubbing requlred, if any, will depend on the degree of entanglement that is present in the feed yarns and not removed by mere tensionlng between dr~w rolls 14 and 18 alone. The number of snubbing pins c~n range ~rom 2 ~o 10 with ~rom 3 to 7 belng preferred.
m e disentangled parallelized crimped continuous filament yarns leavin~ draw roll 18 pre~erably are in such condltion that the in~ividual fil~ments o~ the yarns can be separated ~rom one ano$her wlth at most little di~turbance o~ the remainder of the yarn. The relation-ship between fllaments o~ a continuous fil~ment yarn can be descrlbed in terms o~ coherency factor as de~cribed in Bunting and ~elson, U.S. Patent 2,9859995. Typically, th~
crimped yarns fed to draw roll ~4 will have a cohere~cy ~actor greater than 35. In the present i~vention, the lower the coherency iac~or o~ the feed yarns leavl~g roll 18, the better is the heather result. Preferably, the removal of the disentanglement o~ the feed yarns accom-plished by the dr~w roll~ 14 and 18, ~ith the help o~
snubbing, if necessary9 is such that the feed yarns leav-ing roll 18 have a c~herency ~actor (average o~ the co-herency factor o~ each feed yarn) ~f no greater than 5.
The wettlng of the ~eed yarns by sprays 26 increases the e~lcie~cy o~ the lntermingll~g accom pllshed in the ~et e~tangled zone, ln that ~or all other - 10 - - ~

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conditions remaining equal, greater intermingling iS
achieved with the use of the water spray. ~ny li~uid that increases the intermingling eEficiency can be used.
With respect to the jet intermingling zone 28, the overfeed pre~exably exceeds the withdrawal rate from the zone by at least ~%. An overfeed of greater than 30% is not desired. Within this range, ~he greater the overfeed, the greater is the yarn-to-yarn intermingling. The preferred range of overfeed is from 6 to 25%. While the yarns 8, lO
and 12 are preferentially shown to enter and exit the jet intermingling zone 28 at about right angles and continue in the same direction, the yarns can also follow a path which forms a different angle or no angle at all with respect to the line of entry and exit to the jet inter-mingling zone. The most important feature, however, is that the windup roll is operated at a slower speed that the draw roll 18 so as to ~rovide the ~ercent overfeed desired.
Also important is the forwarding action of the jet inter-mingling zone on the yarn since this also permits operation at the ovexfeed desired. This also permits the filaments to splay and thereby continue intermingling just outside of the exit end of the yarn passageway 32 regardless o the angle of the exiting yarn 29 to the jet body 31. The tension exerted on th~ yarns leaving draw roll 18 by the forwaraing action of the jet intermingling zone is less than the tension exerted between draw rolls 14 and 18 but is sufficient to strip the yarns off of draw roll 18 to prevent back wrap and to provide the feed to the jet inter-mingling zone. If the tension exerted between draw rolls 14 and 18 on the yarns were present on the yarns in the jet ~ 5~
lntermlngling zone, little or no intermingling of filaments would occur~
The yarn gate ls pO8 I tioned ~o that it covers ~rom 30 to ~0~ o~ the yarn passa~eway entry opening, prererably 45 to 60~. The preferred lntermingling fluid is a gasJ prc~erably alr. Generally the air wlll be supplled at a pressure of from 7 to 14 kilograms per square centimeter~ preferably from 7.7 to 12.3 kllograms per square centlmeter.
The expoRure of the disentangled continuous ~ilament yarns contlguous to one another within the ~et body 31 to the turbulent fluld combined with the sudden release o~ the tension on the yarns provides the novel random intermlngling result hereinbe~ore described.
Slnce, the ~eed yarns entering the ~et inter-minglin~ ~one are already crimped, the ~et is not required to do any crimping o~ such yarns, but only lnte~mingle them. I~ the ~et were also required to crimp the yarns, the crimp would be less, giving a less bulky heather yarn product., bec~use o~ the higher denier of ~he yarns being crimped together rather than separatel~, a~d the yarn-to-yarn ~ilament int~rmingling would also be les~.
~ oth the ~eed yarns and the heather yarn made there~rom are ~u~stantlall~ free of twist. ~o twist is pre~erred but some small amount o~ twist ~ay occurr ln the handling o~ the yarne. Preferably, both the feed yarns ~nd the heather yarn have no greater than 1/4 turn o~ twist per 2.~4 cm and more pre~erably no greater than 1/~ turn per 2.54 cm. The ~et i~termingling step occasionally ~iO5~

may cause one feed yarn to cross over another feed yarn to re6emble twist but thls i8 not considered twist because of the randomness at whlch lt occurs~
The process arrangement shown in Fig. l can be chan~cd provlded that the critical steps of di~entan~ling th~ conklnuous fil~ments of the crimped continuous ~ilament feed yarns i8 done and overfeed is established to the Jet intermingling zone. For example, the tensioning done ~or disentangling purposes can be done on feed yarns separately and ln a separate operation from the ~et intermingling, and the tensloned yarn can be wound onto packages which are later fed to the ~et intermingling zone. The pre-ferred overfeeds to the ~et intermingling zone are 4 to 1~ ~nd 6 to 25~ when the tensioning and Jet intermingling are done on an interupted basis or ~n an ln-line basis, respectively. A pair o* nip rolls can be us~d to tension the feed to wind up roll 30.
The component yarns making up the heather yarn of the present inYention can be any synthetic polymer ~ilaments, provided ~hat they are separa~ely colored or separately colorable by diff~rent dye receptiv~ty. the filaments of one component yarn can be the same or di~fer-ent polymer from the filaments o~ another compone~t yarn.
Different dye receptivity can be established by the func-tional groups, such as end groups of the polymer as is well known i~ the art. me preferred heather yarns of the present lnvention are composed o~ all polyamide or all polyester crimped continuous fllament ~eed yarns.
To further illustrate the heather yarn product of the present invention, a yarn was made in apparatus si~ilar ~3)56~

to that shown in Flg. 1 using an 8.4~ overfeed to the ~et-lntermingling zone~ This yarn was made from three crimped continuous fi.lament carpet yarns whlch had different dye r~c~ptivlty to produce the following colors: dark blue, very ll~ht blue (almost white) and yellow. These yarns are lntegrated wlthout twist into the heather yarn of the present invention by the proceRs of the present invention. A nlne cm length of yarn has the following color variations when observed along one side:
Heather A~pearance Strlp of yellow Strip of dark blue Blotch of light blue Strip of medium to dark blue Narrow strip of yellow Blotch of yellow Blotch of greenish blue ~arrow strips of yellow Strip of greenish blue Blotch of yellow to greenish yellow Narrow strip of light blue Narrow strip of yello~
Narrow strip of dark blue Blotch of light greenish blue Blotch of yellow Strip of light greenish blue Strip of dark blue The regions where the component yarn colors, dark blue, light blue, and yellow predominate are randomly interspersed and are of random, short length. The stripq 1~5~14~
of colors noted in the yarn are either parallel to or at an angle with the axis of the yarn and do not give a twist appearance. The portions denoted as blotches are too short to be called strips and may cover the entire width of the ~a~n from the side being observed.
From the oregoing description of the yarn it is apparent that no color pattern repeats itself with any regu-lari~y that could show up as a streak or chevron in a fabric.
The colored appearance of the yarn will depend on the side of observation. Viewed from one side, the color of a single component yarn can predominate whereas when the yarn is viewed from the other side a color blend of the two other component yarns can predominate. On the other hand, if the yarn is viewed from the top or bottom, the observer may see both a color blend and a true color of a yarn component of the heather yarn.
Examples of the present invention in which parts and percent are by weight unless otherwise indicated are as follows:
Example 1 Three component yarns for the heather yarn were used.
One yarn was 1225 denier polyamide cationic-dyeable yarn having a denier per filament of 19 and coherency factor of 47. The second yarn was 1225 denier polyamide low amine end acid-dyeable yarn ha~ing a denier per filament of 19 and coherency factor of 38. The third yarn was 1245 denier poly-amide high amine end deep acid-dyeable yarn having a denier per filament of 15 and coherency factor of 51. Each yarn was previously hot jet crimped by the process of E~ample XXII of U.S.Patent 3,186,155. Apparatus to make the heather yarn was 5G~6 similar -to that shown in Fig. 1. The coherency factors for the yarns leaviny draw roll 18 for the jet intermin~lin~ zone was 3.5, ~.91 and 3.0, respec-tively. The yarn passagewa~ 32 in the jet interminglin~ zone 28 had a length of 25.q milli-m~ters and diameter of 3.18 millimeters. The fluid orifice had a diameter of 2.36 millimeters. The fluid used was air at a pressure of 10.5 kilograms per square centimeter and a temperature of 25C and flow rate of 0.51 cubic meters per minute. The yarn feed speed to the jet intermingling zone 10 was 682 meters per minute from draw roller 18 which exerted a pull out tension on the three feed yarns of one gram per denier. The snubbing device had five snubbing pins. Water was applied to the yarn at the rate of 0.18 milliliters per gram of yarn. The overfeed of the yarn to the jet inter-mingling zone was 15.07 percent.
Example 2 The process conditions for this example were the same as in Example 1 except -that only the cationic dyeable yarn and deep dyeable acid dyeable yarn were used and the overeed to the jet ~ntermingling zone was 13.33 percent.
For both Examples the dyed heather yarns show not only colors of the component yarns but also various blends of such colors randomly interspersed along the yarn.
The distribution of the yarn-to-yarn blended areas among ~he lesser blended and unblended areas, as well as the random lengths and proportions of the latter, enable the heather yarns to be made into pile carpet fabrics which are substantially free of noticeable streaks or chevrons.

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Claims (9)

WHAT IS CLAIMED IS:

1. A process for making a continuous-filament heather yarn wherein a plurality of crimped continuous-fila-ment yarns of different color and/or dye receptivity having a total denier of at least 400 are tensioned to substantially straighten the filaments, followed by randomly entangling the yarns together with a fluid jet in a jet-intermingling zone characterized in that a tension from 0.5 to 1.25 grams per denier is exerted to disentangle and parallelize the filaments prior to the intermingling, the yarns are fed to the jet intermingling zone substantially free of entanglement, the fluid jet serves to forward the combined yarns, and the heather yarn is withdrawn from the jet-intermingling zone at a slower rate than the feed rate to the zone such that the yarns are free of tension during intermingling.

2. The process of Claim 1 wherein the overfeed is in the range of from 4 to 30%.

3. The process of Claim 1 wherein the yarn exiting the jet body forms a rooster tail region in which the fila-ments are still splayed from the pressurized fluid jet wherein intermingling is still occuring.

4. The process of Claim 1 wherein the jet inter-mingling zone includes a jet having a yarn passageway wherein a yarn gate covers a portion of the entry side of the yarn passageway with the effect that fluid exits the yarn passage-way primarily through the opposite end to forward the yarn.

5. The process of Claim 1 wherein the feed yarns after tensioning have a coherency factor of no greater than 5.

6. The process of Claim 1 wherein the yarns enter and exit the jet intermingling zone at right angles.

7. The process of Claim 4 wherein the yarn gate is positioned to cover from 30 to 80% of the yarn passageway entry opening.

8. The process of Claim 1 wherein the yarns are wetted with water between the tensioning and intermingling steps.

9. The process of Claim 1 wherein only one pressurized fluid passageway enters the yarn passageway in the jet-intermingling zone.