Fluid-jet false-twisting method and product

Abstract
A process of producing an assembled yarn, including the steps of providing two or more yarns moving downstream from a supply to a take-up, inserting alternating-direction zones of twist into at least one of the yarns, the at least one yarn having an area of zero twist between said alternating direction zones of twist, combining the at least two yarns to form a single, integrated yarn strand, and intermittently exposing the yarn strand to an air blast to create a zone of intermingled yarns at spaced-apart points along the length of the yarn strand to prevent torsional movement of one yarn relative to the other yarn. According to one preferred embodiment of the invention, the step of exposing the yarn strand to an air blast includes the step of intermingling the yarns at the areas of zero twist.
Description




TECHNICAL FIELD AND BACKGROUND OF THE INVENTION




This invention relates to a method for twisting individual strands of yarn and plying these individually twisted strands around each other, and the yarn made according to the method. More specifically, this twisting action is accomplished by false-twisting, where for a certain yarn length the yarn is twisted a number of turns in one direction and then for another sequential length, it is twisted in the opposite direction. The application also discloses yarns produced according to the method and on an apparatus of the type described.




The nature of false twisting is such that the total number of turns in one direction minus the total number of turns in the opposite direction over the total yarn-length is zero. The method of taking several twisted yarns and combining them by twisting them together to make a multi-stranded yarn has been known for thousands of years. However, plying previously-twisted yarns together is energy and time-consuming, since for every turn in the individual yarn and also for every turn in the plied multi-stranded yarn, the yarn packages must be turned around their axis.




The apparatus and method according to the invention is much more economical since only a relatively short piece of each yarn is twisted around its own axis. The secondary plying occurs automatically since, through the inserted torque, the twisted yarns in the single yarn twist around each other in the direction of the yarn-torque.




The false-twist process requires that care be taken to insure that the false-twisted multi-stranded yarn does not untwist at the place of twist-reversal. This is normally accomplished by attaching fibers of a single yarn to fibers of another, adjoining yarn. Various means of interlocking of these yarns at the twist reversal places have been used, for example, intermingling the fibers through abrasion, ultrasonic bonding, intermingling the fibers with an air-jet directing high-pressure air onto the traveling yarn, for example.




SUMMARY OF THE INVENTION




It is therefore an object of the invention to provide a multi-stranded, plied yarn by twisting a section of a given length of each individual strand around its own axis where the downstream sides of the yarns have twist in one direction and the upstream sides have the same amount of opposite twist. The twist direction is alternated periodically, whereby at twist reversal locations the fibers of the individual yarns are “tacked” by a fluid jet, such as an air-jet, the orifice of which moves substantially in unison direction and velocity with the traveling yarn, thus intermingling the fibers of the yarn effectively and over a relatively short distance.




It is another object of the invention to apply the twist to the individual yarns with stationary twisting elements as the yarns travel past the stationary twisting elements, whereby the direction of twist is periodically reversed.




It is yet another object of the invention to provide a rotating fluid-jet, wherein the timing of the activation of the jet coincides with the desired point of reversal of twist in the traveling yarn.




It is another object of the invention to control the insertion of twist by means of compressed air supplied by twist-inserting air-jets connected to solenoid valves, which are controlled through an electronic controller.




It is another object of the invention to provide a false-twist apparatus wherein compressed air to the twist-inserting jets through solenoid-valves which are controlled through an electronic controller with an electronic input and output where the input is received from the position of the traveling interlacing jet and the output controls the solenoid valves of the twist-inserting air-jets.




It is another object of the invention to provide a false-twist apparatus wherein the intermingling air-jet is placed off-center in the intermingling chamber, generating a partially rotating, intermingling air-stream in one direction where the direction of the rotation augments the self-wrapping of the yarn-strands.




It is another object of the invention to provide that two intermingling air-jets are employed which are placed off-center in opposite directions, each one to augment the self-wrapping of the yarn-strands in both direction.




It is another object of the invention to provide that the twist reversal of each yarn is controlled individually with the result that the twist reversal of one or more yarns is at a different location from the others along the plied yarn.




It is another object of the invention to provide that one or more yarns are not twisted for a given period of time or may never be twisted at all.




It is another object of the invention to provide that one or more yarns are twisted in opposite directions to another yarn in the plied yarn.




It is another object of the invention to provide that the amount of twist in one or more yarns are varied over the length of the plied yarn.




It is another object of the invention to control the rotational speed of a rotating air-jet in such a manner that the entangling jet moves approximately with the yarn process speed and is placed in such a manner that air is directed against the yarn at the point of twist-reversal of the yarn.




It is another object of the invention to control the rotational speed of a rotating air-jet and of the twisting jets during the operation in order to vary the distance between the places of twist reversal to prevent possible “moireé-effects” in the final product.




It is another object of the invention to control the rotational speed of a rotating air-jet and the timing of the twisting jets during the operation in order to vary the distance between two successive, adjacent points of twist reversal to prevent possible “moireé-effects” in the final product.




These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a process of producing an assembled yarn, comprising the steps of providing two or more yarns moving downstream from a supply to a take-up, inserting alternating-direction zones of twist into at least one of the yarns, said at least one yarn having an area of zero twist between said alternating direction zones of twist, combining the at least two yarns to form a single, integrated yarn strand, and intermittently exposing the yarn strand to an air blast to create a zone of intermingled yarns at spaced-apart points along the length of the yarn strand to prevent torsional movement of one yarn relative to the other yarn.




According to one preferred embodiment of the invention, the step of exposing the yarn strand to an air blast includes the step of intermingling the yarns at the areas of zero twist.




According to another preferred embodiment of the invention, the step of exposing the yarn to an air blast includes the steps of intermingling the yarns at the areas of zero twist, and intermingling the yarns at spaced-apart points along the length of the yarn strand other than at the areas of zero twist.




According to yet another preferred embodiment of the invention, the step of exposing the yarn to an air blast includes the step of intermingling the yarns at random points along the length of the yarn strand.




According to yet another preferred embodiment of the invention, the step of exposing the yarn to an air blast includes the step of intermingling the yarns at predetermined points along the length of the yarn strand.




According to yet another preferred embodiment of the invention, the step of exposing the yarn to an air blast includes the steps of intermingling the yarns at random points along the length of the yarn strand, and intermingling the yarns at predetermined points along the length of the yarn strand.




According to yet another preferred embodiment of the invention, the step of inserting alternating-direction zones of twist into at least one of the yarns comprises applying an air blast-induced torque to said yarn.




According to yet another preferred embodiment of the invention, the step of intermittently exposing the yarn strand to an air blast includes the step of moving the air blast along the direction of travel of the yarn strand as the yarns are intermingled to thereby reduce the length of the zone of intermingled yarns.




According to yet another preferred embodiment of the invention, the step of moving the air blast includes the step of moving the air blast at a linear speed equal to the linear speed of travel of the yarn strand.




According to yet another preferred embodiment of the invention, the step of moving the air blast includes the step of moving the air blast at a linear speed not equal to the linear speed of travel of the yarn strand.




According to yet another preferred embodiment of the invention, the step of inserting alternating-direction zones of twist into at least one of the yarns comprising the step of inserting more turns of twist per unit length of yarn in one direction than in the other direction.




According to yet another preferred embodiment of the invention, the step of inserting alternating-direction zones of twist comprises the step of inserting alternating zones of “Z twist, “S” twist and zero twist.




According to yet another preferred embodiment of the invention, the step of inserting alternating-direction zones of twist comprises the step of changing the direction of twist in fewer than all the yarns at a given time.




According to yet another preferred embodiment of the invention, the process includes the step of delaying or advancing the step of inserting alternating-direction zones of twist into at least one of the yarns relative to the step of intermittently exposing the yarn strand to an air blast to create a zone of intermingled yarns at spaced-apart points along the length of the yarn strand.











BRIEF DESCRIPTION OF THE DRAWINGS




Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the invention proceeds when taken in conjunction with the following drawings, in which:





FIG. 1

is a simplified, schematic, perspective view of a fluid-jet false-twisting apparatus according to an embodiment of the present invention;





FIG. 2

is a side elevation of the embodiment of the invention shown in FIG.


1


.





FIG. 3

shows in a close-up the twisting process according to an embodiment of the invention wherein four yarns are false-twisted;





FIG. 4

shows in perspective view the air operated twister block;





FIG. 5

shows in front view the air operated twister block;





FIG. 6

is a side elevation in vertical cross-section of the twist-inserting air ducts for S-twist above and Z-twist below the twisting block;





FIG. 7

is a horizontal cross-section of the twister block shown in

FIG. 6

;





FIG. 8

illustrates the twist-inserting air ducts for Z-twist above and S-twist below the twisting nozzle;





FIG. 9

is a horizontal cross-section of the twister block shown in

FIG. 8

;





FIG. 10

is a longitudinal sectional view of a length of a plied yarn according to an embodiment of the invention;





FIG. 11

is an exploded view of a rotary air-jet assembly according to an embodiment of the invention;





FIG. 12

is a cross-section through a rotary air-jet assembly having one air-jet orifice;





FIG. 13

is a cross-section through a rotary air-jet assembly having two air-jet orifices;





FIG. 14

is a cross-section through air-jet assembly shown in

FIG. 12

, with air escaping for the fiber entangling action;





FIG. 15

shows in front view the rotating air-jet orifice in centered position;





FIG. 16

shows in front view the air-jet orifice in an off-centered position with its effect on the two different yarn reversals;





FIG. 17

shows in front view the air-jet orifice in an off-centered position toward an off-centered position opposite that in

FIG. 16

, with its effect on the two different yarn reversals;





FIG. 18

is a timing diagram of the input and output of the electronic controller for an air-jet nozzle having one air-jet orifice;





FIG. 19

is a timing diagram of the input and output of the electronic controller for an air-jet nozzle having two air-jet orifices;





FIG. 20

is a chart showing the timing of the air-jet orifice in relation of the point of twist reversal in the processed yarn; and





FIG. 21

is a simplified, schematic, perspective view of a fluid-jet false-twisting apparatus according to another embodiment of the present invention











DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE




Referring now specifically to the drawings, a fluid-jet false-twisting apparatus is shown schematically in FIG.


1


and generally indicated at broad reference numeral


10


. In general, multi-filament yarns


11


are taken from respective supply packages


12


and passed through a yarn separator


14


, four twist-inserting air-jets, referred to as “twister blocks


15


” (one for each yarn


11


) and a rotary air jet assembly


20


, where the yarn


11


is plied by the combined action of the twister blocks


15


and the rotary air jet assembly


20


in the manner according to the invention as described in this application. Air is supplied to the twister blocks


15


from a source of pressurized air by means of solenoid valves controlled by mechanical, electromechanical or, preferably, electronic means (not shown). The length of the yarn upstream of the twister blocks


15


can be less than twice the distance between each twist reversal, and in some applications as low as one-to-one, a substantial advantage over prior art processes.




The yarns


11


, now in plied form, are guided around overfeed drive rolls


22


,


23


where the tension on the plied yarns


11


is reduced to a predetermined extent before delivery to a take-up package


25


.





FIG. 2

shows the same fluid-jet false-twist apparatus


10


schematically in side elevation.




In commercial production, a predetermined number of the fluid-jet false-twist apparatuses


10


will be positioned on a single frame for simultaneous operation. The number of units


10


on a single frame may be similar to the number of units on, for example, a winder.




Referring now to

FIG. 3

, the yarn separator


14


has four elongate, vertically-oriented wings


14


A-


14


D. The wings


14


A-


14


D separate the yarn path into four physically-separate zones and thereby keep the individual yarns


11


from touching and twisting together prior to passage into the twister blocks


15


. As shown in

FIG. 3

, the yarns


11


above the twister blocks


15


are twisted in a Z-direction; the yarns


11


between the twister blocks


15


and the rotary air-jet assembly


20


are twisted in S-direction; and the plied yarn


11


below the rotary air-jet assembly


20


are twisted in Z-direction. Sufficient yarn length is needed upstream of the twister blocks


15


for the backed-up twist to accumulate.




Referring now to

FIGS. 4 and 5

, each of the twister blocks


15


has a vertically-oriented bore


27


through which a respective yarn


11


passes. Each of the twister blocks


15


also has two air ducts


28


,


29


which communicate with the bore


27


for communicating air flow. As is shown, the axes of respective ducts


28


,


29


are laterally offset with respect to the axis of the bore


27


. Therefore, one of the ducts


28


,


29


supplies pressurized air which is laterally offset with respect to the axis of the yarn


11


passing through the bore


27


and impinges on the moving yarn


11


in such manner that the air in one of the ducts


28


,


29


creates clockwise twist in the yarn


11


and the air in the other of the ducts


28


,


29


creates counterclockwise twist.




In

FIGS. 4 and 5

, the twister block


15


is shown with pressurized air being injected into duct


29


to insert twist in a clockwise manner, with the result that the yarn


11


above the twister block


15


has Z-twist and the yarn


11


below the twister block


15


has S-twist.





FIG. 6

shows twister block


15


in vertical cross-section, and

FIG. 7

shows a cross-section of the twister block


15


viewed from the bottom, again showing a clockwise twisting action by the air-jet generating S-twist in yarn


11


above the twister block


15


and Z-twist in the yarn


11


below the twister block


15


.





FIG. 8

shows a twister block


15


in vertical cross-section, and

FIG. 9

shows a cross-section of the same twister block


15


viewed from the bottom. As shown, counterclockwise twist generates Z-twist in yarn


11


above the twister block


15


and S-twist in the yarn


15


below the twister block


15


. As noted above, four of these twister blocks


15


are grouped to receive respective yarns


11


as delivered from the upstream supply packages


12


. See

FIGS. 1 and 2

.




Referring now to

FIG. 10

, a section of the plied yarn


11


is illustrated schematically in further detail. The plied yarn


11


is comprised of a “S”-twisted portion


11


A, and an “Z”-twisted portion


11


B separated by a twist reversal segment


11


C constructed of entangled fibers in the manner described below. The spacing of these twist reversal segments


11


C is a significant factor in the ultimate characteristics of the yarn. The twist in the yarns


11


is locked into the yarn in the alternate directions by the twist reversal segments


11


C.




Referring now to

FIG. 11

, the rotary air-jet assembly


20


is shown in an exploded view. A drive motor


30


is mounted on the machine frame (not shown). A protective shroud


31


is positioned on one side of the motor


30


and encloses several components of the rotary air-jet assembly


20


. A manifold housing


32


is mounted in shroud


31


and carries an air manifold


33


which supplies pressurized air to the rotary air-jet assembly


20


. Air is supplied to the manifold by an air inlet port


33


A. A rotating, cylindrical air-jet carried for rotation on the motor shaft


35


of the drive motor


30


. Alternatively, the air-jet nozzle


34


may be driven by a belt, gear transmission or other suitable power transmission device. Rotating nozzle


34


is provided with an air-jet orifice


37


through which air may pass at predetermined intervals.




Shroud


31


is provided with a cut-away section


39


defined by the walls of shroud


31


, into which is placed a yarn twister plate


40


. Yarn guide plate


40


is provided with a vertically-oriented yarn slot


41


through which the plied yarns


11


pass after leaving the twister blocks


15


. A yarn slot orifice


42


in the yarn slot


41


communicates with the air-jet nozzle


34


. The yarn guide plate


40


fits over the cut-away section


39


to guide the plied yarn


11


properly past the air jet nozzle


34


.




A cover


45


is positioned over the yarn slot


41


of the yarn guide plate


40


to prevent uncontrolled escape of air from the proximity of the yarn


11


and to produce in cooperation with the yarn guide plate


40


the air turbulence which entangles the yarn


11


. The cover


45


has an upstream yarn entrance


45


A and a downstream yarn exit


45


B. An end cap


46


encloses the end of the shroud


31


. Note that the air-jet nozzle


34


is the only moving part of the air-jet assembly


20


other than the shaft and associated elements of the motor


30


.




Referring now to

FIG. 12

, the air-jet assembly


20


is shown in vertical cross-section. Air inlet port


33


A feeds pressurized air into the manifold


33


. Air is ejected from the manifold through an air outlet port


48


. The forward walls of the manifold


33


defining the air outlet port


48


are arcuately shaped to seal against the inside wall of rotating air-jet nozzle


34


to prevent air from escaping into the interior of the air-jet nozzle


34


. As the air-jet nozzle


34


rotates, the air-jet orifice


37


moves past the air outlet port


48


. Each complete rotation thus creates a pulse of pressurized air which passes though the air outlet port


48


, the air-jet orifice


37


, the yarn slot orifice


42


and into the yarn slot


41


in the yarn guide plate


40


. The distance between the air-jet nozzle


34


and the yarn guide plate


40


should be as short as possible in order to achieve a short, dense twist reversal segment


11


C.




In the position shown in

FIG. 12

, the air-jet orifice


37


is not aligned with the yarn slot orifice


42


and thus air does not exit to the yarn slot


41


, and air cannot entangle the yarn


11


.




As is shown in

FIG. 13

, two air-jet orifices


37


A and


37


B can be formed in the air-jet nozzle


34


, thus permitting the formation of two twist reversal segments


11


C for each rotation of the air-jet nozzle


34


. Other arrangements are possible, and need not be symmetrical. For example, twist reversal points which are at varying distances from each other can be created by selective placement of air-jet orifices


37


at different spacings around the circumference of the air-jet nozzle


34


.





FIGS. 14 and 15

illustrate the twist reversal formation position of the air-jet nozzle


34


. The air-jet orifice


37


communicates for passage of pressurized air from the air-jet orifice


37


into the area of the yarn


11


by passing into the area of the yarn slot


41


. The inside wall of the cover


45


acts as diffuser to create randomly swirling jets of high-pressure, high velocity blasts of air which pass in and through the yarn


11


, tangling the yarn


11


at the point where the yarn


11


is exposed to the air blast and forming the twist reversal segments


11


C.




If the yarn


11


is traveling with the same velocity as the air-jet nozzle


34


, the air-jet nozzle


34


will entangle a given spot on the yarn


11


for each passage of the air-jet orifice


37


past the yarn slot


41


. In this circumstance, the length of the twist reversal segment


11


C should be approximately no more than the length of the yarn slot orifice


42


. By increasing or decreasing the velocity of the air-jet nozzle


34


relative to the velocity of the yarn


11


through the yarn slot


41


and past the yarn slot orifice


42


, the size of the twist reversal segments


11


C can be controlled with a very high degree of precision.




In

FIG. 15

, the cover


45


is removed to show the position of the air-jet orifice


37


. Note that in this view the air-jet orifice


37


is laterally centered with reference to the yarn slot orifice


42


. In this position the air blast will create a generally symmetrical tangle of fibers in the yarn


11


—neither favoring the Z-twist or S-twist direction.




In

FIG. 16

(top section) the air-jet opening has been laterally shifted to the right in relation to the yarn slot orifice


42


. The result of this displacement of the air-jet orifice


37


is that the air blast helps the self-twisting action of the plied yarn


11


when it changes from Z-twist to S-twist, resulting in a very short twist reversal segment


11


C. See middle section of FIG.


16


.




However, if the plied yarn


11


changes from S-twist to Z-twist the off-center air-jet orifice


37


partially untwists the plied yarn


11


, resulting in a longer twist reversal segment


11


C of lower twist. See bottom section of FIG.


16


.





FIG. 17

shows how the opposite occurs when the air-jet orifice


37


is moved laterally off center to the left. The proper arrangement for a short point of twist reversal is to use an air-jet nozzle


34


with two air-jet orifices


37


A and


37


B (

FIG. 13

) where one air-jet orifice


37


A or


37


B is laterally offset to the right of the yarn slot orifice


42


to entangle the plied yarn


11


when the twist changes from “Z” to “S”; and use the other of the air-jet orifices


37


A or


37


B, which is offset to the inside of the yarn slot orifice


42


, to entangle the plied yarn


11


when the twist changes from “S” to “Z”.




Referring now to

FIG. 18

, the table illustrates that the active air-blast time of the rotary air-jet assembly


20


is used to time the “on” and “off” time of the twister blocks


15


for a air-jet nozzle


34


with a single air-jet orifice


37


. It should be noted that the air to the “Vortex 2” (“Z-twist”) twister block


15


is turned on before the air for the “Vortex 2” (“S-twist”) twister block


15


is turned off. This is accomplished through electronic timing. The same type of timing is also used for the “Vortex 1” (S-twist) and Vortex 2 (Z-twist) twister blocks


15


. This overlapping timing can be used if desired to achieve a short as possible twist reversal segment


11


C in the plied yarn


11


since there is some unavoidable delay in the time from when the solenoid is switched on until the air is fully active in the twister blocks


15


.





FIG. 19

shows the timing for a rotary air-jet assembly


20


with an air-jet nozzle


34


having the two circumferentially-offset air-jet orifices


37


A and


37


B (

FIG. 13

) where the two air-jet orifices


37


A and


37


B are laterally offset to each other and are laterally displaced from the center of the yarn slot orifice


42


to accomplish a short twist reversal segment


11


C.




The timing diagram in

FIG. 20

shows how the rotational speed of the rotary air-jet assembly


20


is controlled. An electronic drive (not shown) for the rotary air-jet assembly


20


is programmed in such a manner that the air-jet orifice


37


reaches the velocity of the traveling plied yarn


11


during the time that entangling of the yarn


11


is taking place. The rotational speed of the air-jet nozzle


34


with its air-jet orifice


37


is slowed down between each splicing cycle in order to wait for the next twist-reversal, at which time it has been brought up speed to match the velocity of the plied yarn


11


.




The desired yarn-length between the twist reversal segments


11


C and the processing speed of the yarn


11


dictates the velocity profile of the rotary air-jet assembly


20


. The relationship of the rotary air-jet assembly


20


in relation to the plied yarn


11


is given in FIG.


20


. The rotational velocity of the air-jet nozzle


34


is timed in two basic ways:




First, the air blast from the air-jet orifice


37


is timed to coincide with the passing of the point where the twist reversal segment


11


C of the yarn


11


is to be formed. Secondly, the rotational speed of the air jet nozzle


34


matches the velocity of the traveling yarn


11


in order that the air blast is, relatively speaking, stationary with the point of creation of the twist reversal segment


11


C during the entangling process. The shaded area shown below the rotational velocity line in

FIG. 20

is the integral of the rotational velocity and the process time and is equal to the angular distance between two air-jet orifices


37


A and


37


B of the rotary air-jet assembly


20


shown in FIG.


13


. The electronic controller for the drive motor


30


of the rotary air-jet assembly


20


is not shown, but may be a known angular encoder on the drive motor


30


. It is naturally understood that the distance between the twist reversal segments


11


C can be changed through the electronic controller, which will automatically adjust the speed of the drive motor


30


and hence of the air-jet nozzle


34


to match the requirements of the system to cause tangling of the yarn


11


at the desired points of twist reversal, and matching of the velocity of the air-net nozzle


34


with the velocity of the traveling yarn


11


.




Alternatively, the electronic control of the rotary air-jet assembly


20


may be by an encoder on the drive of the take-up winder


25


(FIG.


1


), which is then used as the master input for the electronic control, and from which the location of the point of twist reversal and the point where the yarn


11


is entangled is determined.




Other variations are also possible, including controlling each of several rotary air-jet assemblies


20


independently by utilizing different reversal timing, by preventing air to one or more air-jet orifices


37


for a given time, or by having an opposite twist action take place in one or more of the air-jet nozzles


34


.




Referring now to

FIG. 21

, a fluid-jet false-twisting apparatus according to another embodiment of the invention is shown and generally indicated at broad reference numeral


100


. In general, multi-filament yarns


101


are taken from respective supply packages


102


and passed through a yarn separator


104


, four twist-inserting air-jets, referred to as “twister blocks


105


” (one for each yarn


101


) and a rotary air jet assembly


120


, where the yarns


101


are plied by the combined action of the twister blocks


105


and the rotary air jet assembly


120


in the manner described above in relation to

FIGS. 1-20

. Air is supplied to the twister blocks


105


from a source of pressurized air by means of solenoid valves controlled by mechanical, electromechanical or, preferably, electronic means (not shown).




The yarns


101


, now in plied form, are guided around overfeed drive rolls


122


,


123


where the tension on the plied yarns


101


is reduced to a predetermined extent before delivery to a yarn accumulator


130


and to a downstream take-up winder


140


. The yarn accumulator may be a Belmont Model AC-50 accumulator, and the winder may be a Model AD-25 take-up winder. The yarn accumulator


130


helps buffer variations in yarn tension, and permits the system to continue operating during package changes. In addition, any lengths of defective yarn can easily be seen in the accumulator and removed during machine operation. The accumulator


130


may act as the “master encoder” for purposes of determining actuation of the various twist inserting and entangling functions described above.




Alternatively, the overfeed drive rolls


122


,


123


may be removed and replace with a nip roll (not shown), in which case the nip rolls may be used as the constant speed master off of which the other functions of the fluid-jet false-twisting apparatus


100


are timed.




An apparatus and method for twisting individual strands of yarn and plying these individually twisted strands around each other is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims.



Claims
  • 1. A yarn processing apparatus for producing an assembled yarn having alternating-direction twist zones along its length, comprising:(a) a yarn supply and a yarn take-up defining a yarn path therebetween for at least first and second yarns defining a yarn strand; (b) a twist-inserting device for inserting alternating-direction zones of twist into at least one of the first and second yarns of the yarn strand, the at least one of the first and second yarns having an area of zero twist between said alternating direction zones of twist; (c) a moving air blast device for moving an air-jet nozzle along a portion of the yarn path in timed relation to the movement of the yarn strand to intermittently expose the moving yarn strand to a moving air blast being emitted from the air-jet nozzle to create a zone of intermingled yarns at each area of zero twist of the yarn strand to prevent torsional movement of said first yarn relative to said second yarn, said air blast device including a speed control device for: (i) moving the air blast device at a first predetermined rate of speed along the direction of travel of the yarn strand as the yarns are intermingled at the areas of zero twist to thereby reduce the length of the zone of intermingled yarns; and (ii) moving the air blast device at a second predetermined rate of speed less than the first rate of speed between the areas of zero twist sufficient to permit a predetermined distance between zones of intermingled yarns.
  • 2. A yarn processing apparatus according to claim 1, wherein the air blast device includes:(a) an enclosure having an air-jet orifice directed at the yarn path; (b) an air-jet nozzle positioned for rotation within the enclosure for directing the air blast through the air-jet orifice during each rotation of the air-jet nozzle during a predetermined period of time during which the air-jet nozzle is in air-flow communication with the orifice.
  • 3. A yarn processing apparatus according to claim 2, and including an electronically-controlled motor for rotating the air-jet nozzle in a timed relationship with the movement of the yarn strand whereby the air blast directed at the yarn strand through the air-jet orifice is timed to coincide with the passing of the area of zero twist of the yarn strand for creation of the zone of intermingled yarns.
  • 4. A yarn processing apparatus according to claim 2, and including an electronically-controlled motor for rotating the air-jet nozzle in a timed relationship with the movement of the yarn strand whereby the air blast directed at the yarn strand through the air-jet orifice is timed to coincide with the passing of the area of zero twist of the yarn strand for creation of the zone of intermingled yarns, the rotational speed of the air-jet nozzle being controlled by the motor to match the speed of the of the moving yarn strand in order that the air blast is in a stationary relationship with the point of creation of the zone of intermingled yarns.
  • 5. A yarn processing apparatus according to claim 3 or 4, wherein the electronic-controlled motor includes an angular encoder for determining the position of the rotating air-jet nozzle.
  • 6. A yarn processing apparatus according to claim 3 or 4, and including a position encoder cooperating with a motor driving the take-up, an output signal from the take-up motor position encoder comprising a master input signal for the electronically controlled air-jet nozzle motor for rotating the air-jet nozzle in timed sequence with the location of the zone of zero twist.
  • 7. A yarn processing apparatus according to claim 1, wherein the moving air blast intermingles the yarns at predetermined points along the length of the yarn strand.
  • 8. A yarn processing apparatus according to claim 1, wherein the twist-inserting device includes means for inserting more turns of twist per unit length of yarn in one direction than in the other direction.
  • 9. A yarn processing apparatus according to claim 1, wherein the twist-inserting device includes means for changing the direction of twist in fewer than all the yarns at a given time.
  • 10. A yarn processing apparatus for producing an assembled yarn having alternating-direction twist zones along its length, comprising:(a) a yarn supply and a yarn take-up defining a yarn path therebetween for at least first and second yarns defining a yarn strand; (b) a twist-inserting device for inserting alternating-direction zones of twist into at least one of the first and second yarns of the yarn strand, the at least one of the first and second yarns having an area of zero twist between said alternating direction zones of twist; (c) a moving air blast device for moving an air-jet nozzle along a portion of the yarn path in timed relation to the movement of the yarn strand to intermittently expose the moving yarn strand to a moving air blast being emitted from the air-jet nozzle to create a zone of intermingled yarns at each area of zero twist of the yarn strand to prevent torsional movement of said first yarn relative to said second yarn, said air blast device including a speed control device for: (i) moving the air blast device at a first predetermined rate of speed along the direction of travel of the yarn strand as the yarns are intermingled at the areas of zero twist to thereby reduce the length of the zones of intermingled yarns; and (ii) moving the air blast device at randomly varying rates of speed less than the first rate of speed between the areas of zero twist sufficient to permit random distances between the zones of intermingled yarns.
  • 11. A yarn processing apparatus for producing an assembled yarn having alternating-direction twist zones along its length, comprising:(a) a yarn supply and a yarn take-up defining a yarn path therebetween for at least first and second yarns defining a yarn strand; (b) a twist-inserting device for inserting alternating-direction zones of twist into at least one of the first and second yarns of the yarn strand, the at least one of the first and second yarns having an area of zero twist between said alternating direction zones of twist; (c) a moving air blast device for moving an air-jet nozzle along a portion of the yarn path in timed relation to the movement of the yarn strand to intermittently expose the moving yarn strand to a moving air blast being emitted from the air-jet nozzle to create a zone of intermingled yarns at each area of zero twist of the yarn strand to prevent torsional movement of said first yarn relative to said second yarn, said air blast device including a speed control device for: (i) moving the air blast device at a first predetermined rate of speed along the direction of travel of the yarn strand as the yarns are intermingled at the areas of zero twist to thereby reduce the length of the zone of intermingled yarns; and (ii) moving the air blast device at a second predetermined rate of speed less than the first rate of speed between the areas of zero twist sufficient to permit a predetermined distance between zones of intermingled yarns, (d) an electronic controller for controlling the speed of movement of the air blast device in relation to the speed of the moving yarn strand in accordance with a predetermined yarn strand construction.
CLAIM OF BENEFIT OF EARLIER-FILED PROVISIONAL APPLICATION

This application is a continuation application of U.S. Ser. No. 09/058,010 filed Apr. 9, 1998. This application claims the benefit of an earlier-filed provisional application entitled “Fluid-Jet False-Twisting Apparatus, Method and Product”, filed on Aug. 28, 1997, Ser. No. 60/057,152.

US Referenced Citations (97)
Number Name Date Kind
2703316 Schneider Mar 1955
2990671 Bunting, Jr. et al. Jul 1961
3531561 Trebu Sep 1970
3744232 Shah Jul 1973
3775955 Shah Dec 1973
3792011 Smith et al. Feb 1974
3853820 Vachon Dec 1974
3921333 Clendinning et al. Nov 1975
3964486 Blaney Jun 1976
4002012 Norris et al. Jan 1977
4074511 Chambley et al. Feb 1978
4083172 Norris et al. Apr 1978
4104855 Chambley et al. Aug 1978
4114549 Chambley et al. Sep 1978
4123893 Chambley et al. Nov 1978
4137921 Okuzumi et al. Feb 1979
4142355 Chambley et al. Mar 1979
4170103 Norris et al. Oct 1979
4170868 Chambley et al. Oct 1979
4173115 Chambley et al. Nov 1979
4173861 Norris et al. Nov 1979
4175177 Potts Nov 1979
4186549 Chambley et al. Feb 1980
4215642 Chambley et al. Aug 1980
4246750 Norris et al. Jan 1981
4276740 Chambley et al. Jul 1981
4279120 Norris Jul 1981
4367070 Hayashi et al. Jan 1983
4489056 Himmelstein et al. Dec 1984
4685909 Berg et al. Aug 1987
4710187 Boland et al. Dec 1987
4762521 Roessler Aug 1988
4770656 Proxmire et al. Sep 1988
4789592 Taniguchi et al. Dec 1988
4798603 Meyer et al. Jan 1989
4800219 Murdoch et al. Jan 1989
4873821 Hallam et al. Oct 1989
4931488 Chiquet Jun 1990
4934134 Niederer Jun 1990
4959410 Eichenauer et al. Sep 1990
4983689 Yu Jan 1991
5003763 Hallam et al. Apr 1991
5012636 Hallam et al. May 1991
5056200 Schwartz et al. Oct 1991
5057368 Largman et al. Oct 1991
5069970 Largman et al. Dec 1991
5076983 Loomis et al. Dec 1991
5108820 Kaneko et al. Apr 1992
5134840 Niederer et al. Aug 1992
5147712 Miyahara et al. Sep 1992
5160472 Zachariades Nov 1992
5162153 Cooke et al. Nov 1992
5179827 Tinsley et al. Jan 1993
5180765 Sinclair Jan 1993
5202178 Turner Apr 1993
5216050 Sinclair Jun 1993
5223546 Morita et al. Jun 1993
5228282 Tinsley et al. Jul 1993
5238968 Morita et al. Aug 1993
5241066 Davis et al. Aug 1993
5252642 Sinclair et al. Oct 1993
5258422 Chang et al. Nov 1993
5273596 Newkirk Dec 1993
5277976 Hogle et al. Jan 1994
5286770 Bastioli et al. Feb 1994
5294469 Suzuki et al. Mar 1994
5321068 De Witt, Jr. Jun 1994
5336552 Strack et al. Aug 1994
5338822 Gruber et al. Aug 1994
5340646 Morita et al. Aug 1994
5382400 Pike et al. Jan 1995
5405887 Morita et al. Apr 1995
5412005 Bastioli et al. May 1995
5424346 Sinclair Jun 1995
5434004 Ajioka et al. Jul 1995
5444113 Sinclair et al. Aug 1995
5446123 Gruber et al. Aug 1995
5462983 Bloembergen et al. Oct 1995
5465566 Edwards et al. Nov 1995
5475080 Gruber et al. Dec 1995
5484881 Gruber et al. Jan 1996
5489474 Shinoda et al. Feb 1996
5500465 Krishnan et al. Mar 1996
5502158 Sinclair et al. Mar 1996
5508378 Ohara et al. Apr 1996
5525706 Gruber et al. Jun 1996
5545681 Honkonen Aug 1996
5557915 Knoff et al. Sep 1996
5577376 McAllister et al. Nov 1996
5593778 Kondo et al. Jan 1997
5598694 Edwards et al. Feb 1997
5619849 McNeill Apr 1997
5637631 Kitada et al. Jun 1997
5644909 Knoff et al. Jul 1997
5691424 Suzuki et al. Nov 1997
5714618 Kimura et al. Feb 1998
5783504 Ehret et al. Jul 1998
Foreign Referenced Citations (11)
Number Date Country
0515203 Nov 1992 EP
569153 Nov 1993 EP
5-140361 Jun 1993 JP
6-207320 Jul 1994 JP
6-207323 Jul 1994 JP
6-207324 Jul 1994 JP
6-248552 Sep 1994 JP
7-133511 May 1995 JP
8-134723 May 1996 JP
9407941 Apr 1994 WO
9408078 Apr 1994 WO
Non-Patent Literature Citations (20)
Entry
Fedorova, R.G. et al., Chemical Abstracts 109(4)24162z, “Composite Fibers From Polyacrylonitrile-Aromatic Polyamic Acid Blends”,Khim. Volokna 2 11-12, 1998.
Slizite, G. et al., Chemical Abstracts 105(26)228372v, “Study of Photochemical Degradation of Articles Produced from Complex Triacetate-Polyamide Fiber”, Nauch. Tr. Vuzov LitSSR, Khimiya i Khim. Teknol, 27 98-102, 1986.
U, Ju Jui et al., Chemical Abstracts 106(12)86124k, “Use of a Reactively Dyed Low-Molecular-Weight Polycaproamide for Production of Colored Polypropylene Fibers”, Khim Volokna 6, 22-24, 1986.
Zhao Delu, Xue Du et al., Chemical Abstracts 105(12)99049u, “Applications of Controlled Degradation in Polypropylene Tape Yarns”, Suliao, 15 5-10, 1986.
Zakirov, I.Z., Chemical Abstracts 102(22)186548n, “Temperature Transitions in Polyacrylonitrile-Fibron Mixtures”, Vysokomol. Soedin., Ser. B, 27 116-120, 1985.
Sagatova, M. Sh. et al. Chemical Abstracts 102(10)80131f, “Structural and Mechanical Properties of Fibers Produced From Mixtures of Polyacrylonitrile and Chlorinated Poly(vinyl chloride)” Viniti 939-8 Deposited Document 4 (10 pp.), 1984.
Dreizenshtok, G.S. et al., Chemical Abstracts 99(8)54963d, “Cellulose Decomposition in the Sintering of Fibers from Poly(tetrafluoroethylen) Dispersions”, Khim. Volokna, 3 33-34, 1983.
Gusev, V.K. et al., Chemical Abstracts 96(10)70305j, “Two-Component Acetate Threads”, Khim. Volokna, 6 31-32 1981.
Zakirov, I.Z., Chemical Abstracts 96(4)21192M, “Effect of Small Amounts of Polymeric Additives on Structural-Mechanical and Thermal Properties of Synthetic Fibers Spun By a Wet Method”, 3-i Mezhdunar. Simpiz. po Khim. Voloknam. Kalinin. 1981, Kalinin, 5 105-110, 1981.
Fedorova, R.G. et al., Chemical Abstracts 188(16)106639x, “Structural Thermal Stabilization of Fibers Based on Aromatic and Heterocyclic Polymer Blends”, Prepr.-Mezhdunar. Simp.Khim. Voloknam, 2nd 4 36-45, 1977.
Geleji, Frigyes et al. Chemical Abstracts 82(14)87465v, “Bicomponent Fiber Structures on Polypropylene Basis”, J. Polym. Sci., Polym. Symp., 42, 713-716, 1973, Pt. 2.
Whittington, Lloyd R., Whittington's Dictionary of Plastics, p. 258, 1968.
Database WPI, Derwent Publications Ltd., Database WPI, EP 640474, (H. Utz), “Laminated Film Manufactured By Vacuum Deposition of Functional Layer Between Two Films”, Abstract.
Database WPI, Derwent Publications Ltd., Database WPI, JP 6-212511 A, (Unitika Ltd.), “Biodegradable Staple Fiber Useful for Sanitary Napkin”, Abstract.
Database WPI, Derwent Publications Ltd., Database WPI, JP 9-041220 A, (Unitika Ltd.), “Biodegradable Polyester Fiber”, Abstract.
Chemical Abstracts 114(22)209209s: abstract of laid open Japanese patent application JP 3040865.
Chemical Abstracts 119(24)252062d: abstract of laid open Japanese patent application JP 5163616.
Chemical Abstracts 120(8)79336s: abstract of laid open Japanese patent application JP 5093317.
Chemical Abstracts 122(2)12043s: abstract of laid open Japanese patent application JP 6212548.
Chemical Abstracts 122(2)12091f: abstract of laid open Japanese patent application JP 6248515.
Provisional Applications (1)
Number Date Country
60/057152 Aug 1997 US
Continuations (1)
Number Date Country
Parent 09/058010 Apr 1998 US
Child 09/327846 US