GB2166168A

GB2166168A - Looped core and effect yarn

Info

Publication number: GB2166168A
Application number: GB08521616A
Authority: GB
Inventors: Neville Geoffrey Greenberg
Original assignee: American & Efird Mills Inc
Current assignee: American & Efird Mills Inc
Priority date: 1984-10-25
Filing date: 1985-08-30
Publication date: 1986-04-30
Also published as: KR860003373A; JPH0355860U; GB2166168B; KR930003916B1; GB8521616D0

Abstract

A method and apparatus for forming a yarn or sewing thread from core and effect yarns. The effect yarn which is multi filamentary is drawn at no higher than a normal drawing ratio for material from which the effect yarn is made and the effect yarn is softened by sufficient heating, in order to prevent rupturing of the effect yarn during drawing. The core or effect yarn is passed through a wetting device to aid aspiration and entanglement of the core and effect yarns in a fluid jet device. The effect yarn is overfed to the jet device to aid in the formation, together with the core yarn, of a highly entangled looped yarn which is subsequently set by a heated roller while contraction of the yarn is prevented. The core yarn can also be drawn at or below its normal drawing ratio in order to aid in developing thread tenacity and ensure an acceptable elongation at break after dyeing or subsequent wet processing.

Description

SPECIFICATION Highly entangled thread development Field of the Invention The invention is directed to a method and apparatus forfluid jettexturing ofmultifilamentyarns. The invention is specifically applicable for using fluid jet texturing to produce sewing thread according to the "core and effect" method.

Background of the Invention Thetechniquesoffluid orairjettexturingto pro- duce highly entangled mulitfilament yarns or sewing thread is gaining prominence. The finished product falls into two principal categories. First, a relatively low level ofthread entanglement usually supplemented by twisting to improve sewing performance. And second, a high level of thread entanglement utilizing the "core and effect" principal to optimize tenacity and modulus. The latter of these two categor ies generally provides thread oryarn having a better overall performance as compared to the first category.

United Kingdom PatentApplication 2,092,189A corresponding to U.S. Patent 4,497,099 proposes to induce a high level of shrinkage in one or more components comprising the effect yarn by drawing the components more than normal. This high level of shrinkage is used to reduce the size of the effect yarn loops in order to create locked in buds around a central core yarn component while passing the whole yarn around a heated roll and holding the yarn to a predetermined length. Thus, there is produced a yarn in which there is a complete absence of loops on the surface ofthefinished product in which the finished product is completely stable in that itwill not experience shrinkage.

However, this method has a distinct disadvantage.

Namely, when drawing the effectyarn at a drawing ratio higherthan normal, it is possible to rupturethe filaments ofthe yarn thereby affecting the production and the quality ofthe finished product Summary of the Invention The invention provides methods and apparatuses for producing a highly entangled yarn which is not subject to the above described disadvantages of Scott.

The methods ofthe invention exhibitthefollowing features: (a) the effect yarn is drawn at or below the normal drawing ratio which reduces the possibility of inconsistent dyeing and controlled shrinkage ofthe loops is obtained by heating the yarn during drawing sufficiently to soften the yarn without rupturing any filaments; (b) the core or effect yarn is wetted to aid aspiration and entanglement ofthe core and effect yarns in the fluid jet; and (c) the set yarn obtained by passing a highly entangled looped yarn around a heated roller maintains loops on the setyarn surface.

Accordingly, the present invention is advantageous in that it produces a yarn or sewing thread in which the possibility of rupture ofthe effect yarn is greatly reduced, since the effect yarn is drawn at or below the normal drawing ratio. the methods of the invention are further advantageous in that aspiration and entanglement in the fluid jet are greatly enhanced by wetting the core or effect yarn. This feature results in a better qualityfinished product in addition to increasing the yield and the efficiency ofthe methods.

Furthermore, subsequenttwisting ofthe air entangled product improves sewing performance.

The first method comprises the following steps: First, drawing an effect yarn, which comprises one or more multifilamentyarns, at a normal drawing ratio for material from which the effect yarn is made.

Second, passing the core or effect yarn, each of which comprises one or more multifilamentyarns, through a wetting device. Third, overfeeding the effect yarn to a fluid jet. Fourth,feeding the core yarn to the fluid jet.

Fifth, forming a highly entangled looped yarn from the core and effectyarns in the fluid jet, the effect yarn having loops on its surface. Sixth, passing the highly entangled loop yarn around a heated rollerwhile preventing the core yarn from contracting. Seventh, annealing and shrinking the surface loops ofthe effect yarn around the core yarn in orderto form a set yarn.

And,finally, winding the setyarn onto a holderfor subsequent processing,while preventing the set yarn from contracting.

The second method includes the following steps: First, drawing an effect yarn, which comprises two or more multifilament yarns, at a normal drawing ratio for the material from which the yarn is made. Second passing the core or effect yarn, each of which comprises one or more multifilament yarns, through a wetting device. Third, inducing differential shrinkage characteristics in the muitifilament yarns, which comprise the effect yarn, by differential draw temperature provided by hot pins. Fourth, overfeeding the multifilamentyarns, which comprise the effectyarn, to a fluid jet. Fifth,feeding the core yarn tothefluid jet.

Sixth,forming a highly entangled looped yarn from the core and effect yarns in the fluid jet, the effect yarn having surface loops. Seventh, passing the highly entangled looped yarn around a heated rollerfor causing the overfed yarn having the highest shrinkage characteristic to lock the loops of the other yarns to form a set yarn, in which loops are maintained.And finally, winding the set yarn onto a holderfor subsequent processing, while preventing the set yarn from contracting.

The third and forth methods, respectively, modify the first and second methods by requiring that the core yarn is also drawn at or below its normal drawing ratio. Drawing both the core and effectyarns ator belowtheir respective normal drawing ratios aids in developing thread tenacity and ensures an acceptable elongation at break after dyeing orsubsequentwet processing.

As noted above, subsequent twisting ofthe finished product further improves sewing performance. Accordingly, each one ofthefour methods described above may include a subsequent twisting step.

The apparatus ofthe invention comprises at least one drawing stage and hot pin fordrawing the effect yarn and may also include a second drawing stage including a hot pin for drawing the core yarn, when the core yarn is comprised of partially oriented yarn (POY). Of course,the second drawing stage would not be necessary when already drawn core yarn is used.

The apparatusforpracticing the second and fourth methods also includes hot pins in the drawing stage used to drawthe effectyarn in orderto induce the differential shrinkage characteristics. Afluidjet, which typically comprises a conventional airjet, is used to receive the core and effect yarns and to produce a highly entangled looped yarn. The appartusfurther comprises a heated roller assemblyfor receiving the high entangled looped yarn from theairjetand for outputting a setyarn while preventing the set yarn from contracting.

When the finished product is to undergo subse quenttwisting the apparatusfurther includes a conventional twister bobbin such as those manufactured by A.B. Carter Inc.

Brief description of the Drawings FIGURE 1 shows an apparatus for practicing a first process according to the invention.

FIGURE 2 shows a modification ofthe FIGURE 1 apparatus.

FIGURE 3 shows a modification ofthe FIGURE 1 apparatus for practicing a second process according to the invention.

FIGURE 4shows a modification ofthe FIGURE 3 apparatus.

FIGURE 5 shows a twister bobbin fortwisting the finished product FIGURES 6and 7 show untwisted and twisted finished products, respectively.

Detailed Description of the Invention Figure 1 shows an apparatus for practicing the first and third methods of the invention for producing an air entangled sewing thread.The apparatus compris esfirstdrawing rollers 10 and hot pin 15andfeed rollers 30 for feeding an effect yarn 70. A second set of drawing rollers 20 together with a hot pin 25 are provided when the core yarn 60 comprises POY, but can be omitted when a drawn core yarn 60 is used, as shown in Figure 2. The core yarn 60 oreffectyarn 70 is fed by feeding rollers 30 or 40, respectively, through a wetting device 50 to the air orfluid jet device 80.The wetting device 50 is shown in all the Figures to wet the core yarn 60, however, this is for convenience only in that, as stated above, eitherthe core or effect yarn can be wetted in the wetting device.

The core and effectyarns enter a movable passage device 100 within the jet device 80 with the effect yarn being overfed. The amount of overfeed can range from 25% to 75% and is determined bythe end use of thefinished product and the denier ofthe coreyarn used, with a higherdeniercoreyarn requiring a higher effect yarn overfeed. The core and effectyarns are caused to interminglewith each other in a mixing chamber 7 10 ofthe jet device 80, the air orfluid entering the jet device 80 at an opening 90. Aswill be readily appreciated by those of ordinary skill in the art, the position ofthe movable passage device 110 determinesthe degree of aspiration andentangle mentoftheya: ns.

It should also be pointed outthat passing the core or effectyarn through the wetting device 50 also significantly aidsthe aspiration andentanglementof the core and effectyarn. Furthermore, since the effect yarns are drawn substantially at or less than the normal drawing ratioformaterial from which the effect yarn is made, controlled shrinkage ofthe loops is obtained and the effect yarn is softened by heating the yarn during drawing, so thatthe likelihood of rupture ofthe effectyarn filaments isthusfurther reduced. The above described features also reduce the possibility of inconsistent dyeing.In addition, as noted above, when the core yarn is also drawn at or lessthanthe normal drawing ratio for material from which it is made, the development ofthethread's tenacity is aided and an acceptable elongation at break after dyeing or subsequent wet processing is ensured.

The highly entangled loop yarn 120 outputfrom the jet device 80 is passed around a roller 130, which is adjustable in position, and passed to a separator roller 140. The highlyentangled loop yarn 120 contains loops 25, as it passes from the separator roller 140 to a heated roller 150 which is preferably heated in excess of 125 C. As the highly entangled loop yarn 120 is passed around the heated roller 150the yarn is set, in thatthe loops shrink and are annealedaroundthe otheryarns. Furthermore, the combination of the position adjustable roller 130, the separator roller 140, the heated roller 150 and a set nip rollers 170 serve to maintain the intermingled yarn at a predetermined length as it is being set.

ltshould be noted that the setyarn 160 maintains loops on its surface, although these loops are somewhat reduced in size as compared to the loops 125 ofthe highly entangled loop yarn 120 outputfrom the jet device 80. The set yarn 160 is provided from the nip rollers 170 to awinding device 180 onto which the set yarn iswound for subsequent processing.

Figure 3 shows a modification ofthe apparatus shown in Figure 1,the modified apparatus being used to practice the second and fourth methods of the invention. In Figure 3, components which are identical to components shown in Figure 1 have identical reference numbers and since these components operate in the same way a detailed description of their operation has been omitted. Thus, the modification of the aforementioned Figure 1 apparatus comprises the inclusion of hot pins 15 and 35 which operate, respectively, in conjunction with the drawing rollers 10 and 45for drawing the effectyarn. The hot pins 15 and 35 are used to induce differential shrinkage in a plurality of multifilamentyarns making up the effect yarn by providing different draw temperatures.

Anothersetofdrawing rollers 20 togetherwith a hot pin 25 are provided when the core yarn 60 comprises POY, but can be omitted when a drawn core yarn 60 is used, as shown in Figure 4. In Figure 3there are shown two multifilamentyarns comprising the effectyarn, but it should be understood thatthis is for convenience only and the invention can also comprise more than two differentially shrinkable multifilamentyarns.

The yarns with differential shrinkage, which comprise the effect yarn, are overfed into the jet device 80.

As stated above, the amount of overfeed can range from 25% to 75% and is determined bythe end use of the finished product and the denier of the core yarn used, with a higher denier core yarn requiring a higher effect yarn overfeed. The core or effectyarn is passed through the wetting device to aid aspiration ofthe high overfeed. The effect and core yarns are entangled in the jet device in the same manneras has been described above with reference to Figure 1. The highly entangled loop yarn output from the jet device is then passed around the heated roller, in a similar manner as has been described with respect to the first method described above, and the surface temperature of the heated rolleris preferably in excess of 125 C.

During its passage around the heated roller, the yarn with the highest induced shrinkage characteristics locks the loops ofthe other yarns while the highly entangled looped yarn and the set yarn which results from passagearoundthe heated roller is prevented from contracting by the combination of rollers, as described above with respect to the first method.

It should be pointed out that although the yarn with the highest shrinkage locks the loops of the other yarns as described above, not all ofthe surface loops are eliminated. The resulting set yarn is then wound on awinding device, similarly as has been described above with respectto the yarn produced by the first described method.

Accordingly, the above described methods result in superior quality sewing thread with the first method producing a more desirable qualitythread as compared to the second method,thethread produced by the first method exhibiting a highertenacityfor medium to lowdenieryarns. Furthermore, the third and fourth methods provide additional advantages over the first and second methods, respectively, in that the development ofthe thread's tenacity is aided and an acceptable elongation at break after dyeing or wet processing is ensured.

Figure 5 shows a conventional twister bobbin 190 and athread guide for subsequent twisting ofthe sewing thread produced by anyfour methods described above. Figures 6 and 7 respectively illustrate the untwisted and the twisted sewing threads produced before and afterthe twisting step carried out in the twister bobbin 190.

Is should be appreciated that the above described methods and apparatuses ofthe preferred embodiments do not limit the scope ofthe present invention in any way, and that various changes and modifications may be made without departing from the spirit and scope ofthe present invention.

Claims

1. A method offorming a yarn from a core yarn and an effect yarn, comprising the steps of: drawing said effect yarn, comprising at least one multifilamentyarn, atsubstantially no higherthan a normal drawing ratio for material from which the effect yarn is made and heating said effect yarn sufficiently in orderto soften the effect yarn, to prevent rupturing the effectyarn during drawing and to reduce the possibility of inconsistent dyeing in a subsequent process; transporting any one of said core and effect yarns, through a wetting device; overfeeding said effect yarn to a fluid jet the amount of overfeeding being dependent on the denier of the core yarn; feeding said core yarn to said fluid jet; forming a highly entangled looped yarn from said core and effect yarns in said fluid jet, wherein said effect yarn has surface loops;; passing said highly entangled looped yarn around a heated roller to form a set yarn, while preventing said highly entangled loop yarn from contracting and preserving said surface loops in said effect yarn; and winding said set yarn onto a holder while preventing the set yarn from contracting.

2. A method as claimed in claim 1 wherein the temperature of said heated roller used in said passing step is in excess of 125 C.

3. A method as claimed in claim 1, wherein the fluid jet used in said forming step is an airjet.

4. A method as claimed in claim 1 ,further comprising a core drawing step for drawing said core yarn when said core yarn comprises POY.

5. A method as claimed in claim 1, furthercomprising the step oftwisting said setyarn.

6. A method of forming a yarn from a core yarn and an effect yarn, comprising the steps of: drawing said effect yarn, comprising at least one multifilamentyarn, at substantially no higherthan a normal drawing ratio for material from which the effectyarn is made and heating said effect yarn sufficently in order to soften the effect yarn, to prevent rupturing the effect yarn during drawing and to reduce the possibility of inconsistent dyeing in a subsequent process; transporting any one of said core and effect yarns through a wetting device; overfeeding said effect yarn to a fluid jet, the amount of overfeeding being dependent on the denier ofthe core yarn; feeding said core yarn to said fluid jet; forming a highly entangled looped yarn from said core and effect yarns in said fluid jet, wherein said effect yarn has surface loops;; passing said highly entangled looped yarn around a heated roller while preventing it from contracting; annealing and shrinking said surface loops around said coreforforming a set yarn; and winding said set yarn onto a holderwhile preventing the set yarn from contacting.

7. A method as claimed in claim 6, wherein the temperature of said heated roller used in said passing step is in excess of 125 C.

8. A method as claimed in claim 6, wherein the fluid jet used in said forming step is an airjet.

9. A method as claimed in claim 6,further compris- ing a core drawing step for drawing said coreyarn when said core yarn comprises POY.

10. A method as claimed in claim 6, further comprising the step oftwisting said setyarn.

11. A method offorming a yarn from a core yarn and an effect yarn comprising the steps of: drawing said effect yarn, comprising a plurality of multifilamantyarns, at substantially no higherthan a normal drawing ratio for material from which said yarn is made and heating said effect yarn sufficently in order to soften the effect yarn, to prevent rupturing the effect yarn during drawing and to reduce the possibility of inconsistent dyeing in a subsequent process; transporting any one of said core and effectyarns, through a wetting device; inducing differential shrinkage in said plurality of multifilamentyarns by differential draw temperatures provided by hot pins; overfeeding said plurality of multifilamentyarns with differential shrinkage comprising said effectyarn to a fluid jet the amount of overfeeding being dependent on the denier ofthe core yarn;; feeding said core yarn to said fluid jet; forming a highly entangled looped yarn from said core and effectyarns in said fluid jet, wherein said effectyarn has surface loops; passing said highly entangled looped yarn around a heated rollerfor causing the overfed yarn having the highest shrinkage to shrink and thus lock the loops of the otheryarns thereby forming a setyarn, wherein said highly entangled looped yarn is prevented from contracting; and winding said setyarn onto a holderwhile preventing the set yarn from contracting.

12. A method as claimed in claim 11, wherein the temperature of said heated roller used in said passing step is in excess of 125 C.

13. A method as claimed in claim 11,wherein the fluid jet used in said forming step is an airjet.

14. A method as claimed in claim 11, further comprising a core drawing step for drawing said core yarn when said core yarn comprises POY.

15. A method as claimed in claim 11, further comprising the step oftwisting said setyarn.

16. A method offorming a yarn from a core yarn and an effectyarn, comprising the steps of: drawing said effect yarn, comprising at least one multifilamentyarn, atsubstantially no higherthan a normal drawing ratio for material from which the effectyarn is made and heating said effect yarn sufficiently in order to soften the effect yarn, to prevent rupturing the effect yarn during drawing and to reduce the possibility of inconsistent dyeing in a subsequent process; transporting any one of said core and effectyarns, through a wetting device; overfeeding said effectyarnto afluidjettheamount of overfeeding being dependent on the denier of the core yarn;; feeding said core yarn to said fluid jet wherein said core yarn has been drawn at substantially no higher than a drawing ratio for material from which the core yarn is made; forming a highly entangled looped yarn from said core and effectyarns in said fluid jet, wherein said effectyarn has surface loops; passing said highly entangled looped yarn around a heated rollertoform a set yarn, while preventing said highly entangled loop yarn from contracting and preserving said surface loops in said effectyarn; and winding said setyarn onto a holder while preventing the set yarn from contracting.

17. A method as claimed in claim 16 wherein the temperature of said heated roller used in said passing step is in excess of 125 C.

18. A method as claimed in claim 16, wherein the fluid jet used in said forming step is an airjet.

19. A method asclaimed in claim 16,further comprising a core drawing step for drawing said core yarn when said core yarn comprises POY.

20. A method as claimed in claim 16,further comprising the step oftwisting said setyarn.

21. A method of forming yarn from a core yarn and an effectyarn, comprising the steps of: drawing said effectyarn, comprising at least one multifilamentyarn, at substantially no higherthan a normal drawing ratio for material from which the effectyarn is made and heating said effect yarn sufficently in order to soften the effectyarn, to prevent rupturing the effect yarn during drawing and to reduce the possibility of inconsistent dyeing in a subsequent process; transporting any one of said core and effectyarns through a wetting device; overfeeding said effectyarn to a fluid jet, the amount of overfeeding being dependenton the denier ofthe core yarn;; feeding said core yarn to said fluid jet wherein said core yarn has been drawn atsubstantially no higher than a normal drawing ratio for material which the core yarn is made; forming a highly entangled looped yarn from said core and effectyarns in said fluid jet, wherein said effectyarn has surface loops; passing said highly entangled looped yarn around a heated rollerwhile preventing itfrom contracting; annealing and shrinking said surface loops around saidcoreyarnforforming asetyarn; and winding said set yarn onto a holderwhile preventing the set yarn from contracting.

22. A method as claimed in claim 21,wherein the temperature of said heated roller used in said passing step is in excess of 125 C.

23. A method as claimed in claim 21, wherein the fluid jet used in said forming step is an airjet.

24. A method as claimed in claim 21, further comprising a core drawing step for drawing said core yarn when said core yarn comprises POY.

25. A method as claimed in claim 21, further comprising the step oftwisting said setyarn.

26. A method offorming yarn from a core yarn and an effect yarn comprising the steps of: drawing said effectyarn, comprising a plurality of multifilamentyarns, at substantially no higherthan a normal drawing ratio for material from which said effect yarn is made and heating said effect yarn sufficiently in order to soften the effectyarn, to prevent ruptureing the effect yarn during drawing and to reduce the possibility of inconsistent dyeing in a subsequent process; transporting any one of said core and effect yarns, through wetting device; inducing differential shrinkage in said plurality a multifilamentyarns by differential draw temperatures provided by hot pins; ; overfeeding said pluralitgof multifilamentyarns with differential shrinkage comprising said effect yarn jet and the amount of overfeeding being dependent on the denierofthe core yarn; feeding said core yarn to said fluid jet wherein said core yarn has been drawn at substantially no higher than a normal drawing ratio for material from which the core yarn is made; forming a highly entangled looped yarn from said core and effectyarns in said fluid jet, wherein said effectyarn has surface loops;; passing said highly entangled looped yarn around a heated rollerforcausing the overfed yarn having the highest shrinkage to shrink and thus lock the loops of the other yarnstherebyforming a set yarn, wherein said highly entangled looped yarn is prevented from contracting; and winding said set yarn onto a holder while preventing the set yarn from contracting.

27. A method as claimed in claim 26, wherein the temperature of said heated roller used in said passing step is in excess of 125 C.

28. A method as claimed in claim 26, wherein the fluid jet used in said forming step is an airjet.

29. A method as claimed in claim 26, further comprising a core drawing step for drawing said core yarn when said core yarn comprises POY.

30. A method as claimed in claim 26, further comprising the step of twisting said set yarn.

31. An apparatus for forming a yarn from a core yarn and an effect yarn, comprising: drawing means including drawing rollersfordrawing said effect yarn at substantially no higher than a normal drawing ratio for material from which the effect yarn is made; feeding means for receiving said drawn effect yarn and said core yarn and feeding out said drawn effect yarn and said core yarn; wetting means for receiving any one of said core andeffectyarnsfrom said feeding means and for wetting and outputting said received yarn; fluid jet means for receiving said drawn effect yarn and for receiving said core yarn, wherein said feeding means overfeeds said drawn effect yarn, and for outputting a highly entangled looped yarn formed from said overfed drawn effect yarn and said core yarn;; setting means including a heated roller for receiving said highly entangled looped yarn and outputting a set yarn in which surface loops are maintained; and holding means on which said set yarn is wound.

32. An apparatus as claimed in claim 31, wherein said drawing means further comprises core drawing rollers when said core yarn comprises POY.

33. An apparatus as claimed in claim 31, wherein said drawing means further comprises hot pins associated with said effect yarn drawing rollers for providing different drawing temperatures to multifila ment yarns which comprise said effect yarns.

34. An apparatus as claimed in claim 31, wherein said drawing meansfurther comprises hot pins associated with said effect yarn drawing rollers for providing different drawing temperatures to multifila ment yarns which comprise said effectyarn.

35. An apparatus as claimed in claim 31, wherein said drawing means further comprises core drawing rollers for drawing said core yarn at substantially no higherthan a normal drawing ratio for material from which said core yarn is made when said core yarn comprises POY.

36. An apparatus as claimed in claim 31, further comprising atwisting meansfortwisting said setyarn.