EP2049717A2

EP2049717A2 - Method and apparatus for warping and method of dyeing of high twisted fine count yarn

Info

Publication number: EP2049717A2
Application number: EP07859584A
Authority: EP
Inventors: Kishor Gajanan Agnihotri
Original assignee: Arvind Ltd
Current assignee: Arvind Ltd
Priority date: 2006-07-10
Filing date: 2007-07-09
Publication date: 2009-04-22
Also published as: WO2008044241A2; WO2008044241A3; US20090320252A1

Abstract

The present invention provides embodiments comprising an apparatus for warping yarns, a comb, method of direct warping of the high twisted fine count yarns and method for dyeing of high twisted fine count yarns on slasher dyeing machine. The apparatus (100) comprises a narrow width warp beam (130), a comb (120) having flexible pins (122) and is configured to high tension which enable direct warping of the high twisted fine count yarns such as voile yarns. The method of direct warping comprises warping of the yarns at high tension onto a narrow width beam. The method of dyeing of the high twisted yarn includes preparing of the beams having high density of high twisted fine count yarns on narrow width of the beam, and dyeing and separating at high tension.

Description

METHOD AND APPARATUS FOR WARPING AND METHOD OF DYEING OF HIGH TWISTED FINE COUNT YARN

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method and apparatus for direct warping and method of dyeing of yarns such as high twisted fine count yarns for example voile yarns.

BACKGROUND ART OF THE INVENTION

Generally, indigo dyeing or sulfur dying is carried out at yarn stage either by slasher or rope dyeing method.

In slasher dyeing, the yarns to be dyed with indigo dye are required to be warped before passing through the dyeing machine to produce a warp beam of the required number of the dyed yarns. Generally, direct warping is used for making warp beams, which warps the yarns parallel with substantially equal tension in the yarns onto a warp beam. A predetermined number of warp beams of warped yarns are assembled on creel of slasher and dyeing is carried out. Total number of ends required in the fabric width is equally divided in the number of warp beams to be put at dyeing machine creel. Normally, 6 to 14 warp beams are set to form a single sheet of yarns, which is dyed by passing through wetting zone, indigo dyeing zone, washing zone, drying zone and leasing zone. Generally, the tension in the yarn while dyeing is increased in the dying process from 375 to 450N. Then the dyed yarn sheet is wound onto a beam. Normally, yarn tension at dyeing is kept up to 10% of the breaking strength of the individual yarn. Further, tension in the leasing zone increases with the decrease in the count of the yarn and increase in the number of the yarns.

However, the known slasher dyeing method is not suitable to dye the fine count high twisted yarns such as voile yarns as these yarns comprises z-z twist, which induces forces in the yarn which induces entanglement and grouping tendency in the yarn This leads into higher number of breakages if tried to warp the yarn by conventional direct warping process. Further, these yams occupy less space across the width of the regular beam due to the fine count that leads to the slippage of the overlapped yarns and uneven tension in the warped yarns. Hence regular beams cannot be used for warping the fine count high twisted yarn. Further, conventional direct warping process cannot be used for the warping of the finer count voile yarn to make a beam for the indigo dying by slasher process as these yarns breaks, becomes slack and form groups if warped on conventional direct warping machines.

Further, conventional rope dyeing machine cannot be used for the indigo dyeing of the voile yarn due to the entangling nature of the voile yarn.

Therefore, there is need of the method and device for warping and indigo dyeing of the fine count high twisted yarns such as voile yarns.

SUMMARY OF INVENTION

It is an object of the present invention to provide an apparatus and a method for direct warping of yarns such as high twisted fine count yarns for example voile yarns.

Another object of the present invention is to provide a method for slasher dyeing of high twisted fine count yarn such as voile yarn by using slasher machine. One embodiment of the present invention presents an apparatus for direct warping yarns, which comprises plurality of creels, each said creel holds bobbin of the yarn; a comb arranged and constructed to guide and allow passage of the yarns parallel to each other without entanglement; a warp beam arranged and constructed for warping the yarns with high yarn density and to avoid slippage of the overlapping yarns, said warp beam is adapted parallel to the comb to warp the yarns in straight condition; and a pressure roller positioned parallel in contact with the warp beam to maintain uniform tension in the warped yarns.

According to this embodiment, the apparatus is configured to warp the yarns at a higher tension onto the warp beam helping warped yarn to remain in straight condition with substantially even tension.

Further, as per this embodiment, the warp beam has narrow width for warping the yarns. Furthermore, the yarn is the high twisted yarn such as voile yarns.

Another embodiment of the present invention comprises a method of direct warping of the high twisted yarns onto a warp beam. The method of direct warping comprises warping of the yarns at high tension onto a narrow width beam to avoid slacking and entanglement of the yarns and to maintain the yarn warped in straight condition with substantially even tension among the warped yarn.

In yet another embodiment, the method of dying of the high twisted yarns such as voile yarns on a slasher dyeing machine comprises; assembling predetermined number of warp beams on creels to obtain required number of the yarns in a yarn sheet; wetting, dyeing washing and drying the yarn sheet; subjecting each dried yarn in the yarn sheet to high tension in the leasing zone thereby gradually separating of each yarn in the yarn sheet before the yarn reaches leasing rod; and winding the yarns on a weaver's beam. Each individual yarn is substantially subjected to a tension more than 20% of breaking strength of individual yarn the yarn.

Furthermore embodiment of the present invention presents a comb to guide and allow passage of the yarns parallel to each other without entanglement comprising a base and plurality of flexible pins extending parallel from the base wherein the pins are free to oscillate radial direction of the yarn passage, which allows passing the yam without entanglement.

The embodiments of the present invention allow dyeing of the voile yarns on the slasher dyeing without entanglement, grouping and/or breakage of the voile yarns. Further, warping apparatus of the present invention can be used to produce weaver beams of the all type of the yarns for various constructions of the fabrics.

BRIEF DESCRIPTION OF DRAWINGS

Reference made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the embodiments of the invention are generally described in the context of these drawings, it should be understood that it is not intended to limit the scope of the embodiments of the invention to these drawings.

Fig 1 shows an apparatus of direct warping according to present invention.

Fig 2 shows a regular warp beam and a regular warp bam having an arrangement according to the present invention.

Fig 3 shows a comb according to the present invention.

Fig 4A shows magnified view of the warp beams mounted on creels of the slasher machine. Fig 4B shows slasher machine used for dyeing;

Fig 5 shows magnified view of a leasing of yarn in leasing zone with lower tension and higher tension in the yarn.

DESCRIPTION OF THE PRESENT INVENTION

In broad, the present invention provides embodiments comprising an apparatus for warping yarns, a comb, method of direct warping of the high twisted fine count yarns and method for dyeing of high twisted fine count yarns on slasher dyeing machine. The apparatus comprises a narrow width warp beam, a comb having flexible pins and is configured to high tension which enable direct warping of the high twisted fine count yarns such as voile yarns. The method of direct warping comprises warping of the yarns at high tension onto a narrow width beam. The method of dyeing of the high twisted yarn includes preparing of the beams having high density of high twisted fine count yarns on narrow width of the beam, and dyeing and separating at high tension.

Referring Fig 1 , it shows an apparatus for direct warping of the yarns (100). The apparatus (100) for direct warping of yarn onto a warp beam (130) according to the present invention essentially comprises plurality of creels (110) for mounting yarn bobbins (112), a comb (120) for passing the yarns (114) straight onto the warp beam (130) and a pressure roller

(132) positioned parallel in contact with the beam to maintain uniform tension in the warped yarns. The apparatus is driven by conventionally known means with few easy modifications to operate the apparatus with present invention.

According to the present invention the yarn is the high twisted fine count yarn such as voile yarn. As it is known that the high twisted yarn are of entanglement nature and has tendency to form groups, accordingly in present invention, regular size of the warp beam (130) arranged and constructed with narrow warping width (w) by introducing two parallel flanges (134) as shown in Fig 2. Alternatively, a warp beam having narrow width can be used. For example, for direct warping of the voile yarns, the warping width of the warp beam according to the present invention can be approximately reduced to half of the original size of the warp beam such as 1200mm width beam is reduced to 500mm.

Further, the apparatus is configured to maintain high tension in the yarn while warping which in combination with the narrow warp width (w) of the beam (130) warps the yarns (112) in straight condition with even tension without entanglement and grouping. The tension in the yarn is increased by using conventionally known tensioners (not shown) and/or by known ways. According to the present invention, the tension for warping voile yarns is maintain more than 12% of breaking strength of the individual yarn for the direct warping of the voile yarns.

As the warping width (w) of the warp beam (130) is narrowed, the pressure drum (134) is adapted in contact with the warp beam (130) to accommodate reduced width of the flanges (134) at warping stage by reducing size as shown in Fig 1. The pressure drum (132) reduces the tension variation in yarn and prevents twisting of yarns together during dyeing. Further, the pressure drum (132) prevents warp beam bulging that may result in reduction in the warp beam density. Further, the pressure drum prevents slippage of yarn while winding onto the warp beam and entanglement of yarn on the warp beam. This facilitates uniform unwinding of the yarn at the dyeing creel. This facilitates uniform unwinding of the yarn at the dyeing creel. Fig 3 shows a comb (120) according to the present invention. The comb (120) has flexible pins (122) extending from the base (124). As another end of the pins (122) is kept free, the pins (122) are free to oscillate in radial direction of the yarns. The oscillation (X) of the flexible pins lessen the vibration of the yarn during warping process thereby avoiding the entanglement and breakage of the high twisted fine count yarn such as voile yarn. According toe the present invention, length of the comb depends upon the warp or winding width of the beam and number of the flexible pins depends upon the number of the yarn ends. The flexible pins are made of flexible material such as metal and preferably stainless steel.

Further, the present invention also provides a method for direct warping of the high twisted yarn such as voile yarns. As per the method bobbins having high twisted yarn are assembled on the creel for direct warping and the ends of the yarns are passed through the comb for winding on a narrow warp beam. Then the yarns are warped on the warp beam having narrow warping width at a tension more than 12% of the single yarn strength. The tension in the yarn and narrow width of the warp beam helps to increase in the density of the yarn ends thereby warps the yarns in straight condition with substantially even tension in the yarns warped with decrease in the slippage of the overlapped yarns. This enables further processing of the high twisted yarns such as dyeing on slasher machine without substantial entanglement nature and breakages of the yarn.

Moreover to the present invention provides a method for dyeing voile yarn, particularly, indigo dyeing voile yarn on slasher dyeing machine (200) as shown in the Fig 4. In this method, the warp beams (210) of high twisted fine count yarns such as voile yarns are prepared by direct warping method of the present invention and/or by using apparatus of the present invention. These warp beams (210) are assembled on creels (220) of the slasher machine as shown in Fig 4A. Though, it is shown in the Fig 4A six numbers of the warp beams mounted on the creels (220), the number of the warp beams to be mounted depends upon the number of the yarns on a warp beam and the number of the yarns to be required on the weaver's beam.

The yarns are pulled from the creels as shown in the Fig 4B by know way to form yarn sheet (230). The yarn sheet (230) is wetted in wetting zone, dyed in the indigo dyeing zone, washed in the washing zone and dried in the drying zone as per know way. But according to the present invention, the tension in the individual yarn in the yarn sheet in the respective zone is maintained high and gradually increased in each zone than the known method of slasher dyeing, where tension normally gradually increases from 375 Newton to 470 Newton for example in the present invention, the tension starts and increases from 500 Newton to 625 Newton for the voile yarns.

According to the present invention, the dried yarn sheet further subjected to a tension of more than 20% of single yarn strength multiplied by number of yarns in the sheet in the leasing zone as shown in Fig 5 to separate the voile yarns for winding on a weaver's beam (not shown). The increase in the tension of yarn in the leasing zone of the dyeing process causes separations earlier as shown in Fig 5, which shows separation of dyed yarns by dotted lines at low tension and separation of the yarns in the dyed yarn sheet at high pressure. The separation of the yarns much prior before leasing rod (240) substantially due to high tension lessens the yarn entanglement in the path, yarn breakage and band formation. The tension in the yarns in the leasing zone of the dyeing process is increased by known way.

Generally, lubricant is not required in dyeing process. However, the inventors used lubricant during the final washing step surprisingly found that voile yarn ends separation was improved with the use of the lubricant.

The lubricants preferably used in the present invention may be selected from the group cationic or non-ionic lubricants.

The present invention also covers indigo dyed voile yarn produced by the method and apparatus of the present invention. The present invention also covers the voile fabric made from the indigo dyed voile yarn by the method and/or apparatus of the present invention.

Other than indigo dye, the high twisted fine count yarn such as voile yarn can be dyed with the sulfur dyes, pigment colours and vat dyes by using the process of the present invention as discussed above.

The present invention allows dyeing of the voile yarns on the slasher dyeing without entanglement, grouping and/or breakage of the voile yarns. Further, warping apparatus of the present invention can be used to produce weaver beams of the all type of the yarns for various constructions of the fabrics.

The above description is included to illustrate embodiments of the present invention for ease of the understanding the invention and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would encompass by the spirit and scope of the present invention. The scope of the invention is to be limited only by the following claims.

Claims

1. An apparatus for direct warping of yams, said apparatus comprising: plurality of creels, each said creel holds bobbin of the yarn; a comb arranged and constructed to guide and allow passage of the yarns parallel to each other without entanglement; a warp beam arranged and constructed for warping the yarns with high yarn density, said beam is adapted parallel to the comb to warp the yarns in straight condition; and a pressure roller positioned parallel in contact with the beam to maintain uniform tension in the warped yarns.

2. The apparatus as claimed in claim 1 wherein the apparatus is configured to warp the yarns at a higher tension onto the beam helping warping of the yarn on the beam in combination with narrow width of the beam without entanglement and grouping of the yarn.

3. The apparatus as claimed in claim 1 wherein the comb comprises a base and plurality of the flexible pins extending from the base free to oscillate in radial direction of yarn passing thereby avoiding breakage and entanglement of the yarns.

4. The apparatus claimed in claim 1 and 3 wherein the beam has narrow width for warping the yarns.

5. The apparatus as claimed in claim 1 and 4 wherein two flanges are adapted on the regular size of the beam to narrow the warping width of the beam.

6. The apparatus as claimed in one of the claims 1 to 5 wherein the yarn is high twisted fine count yarn such as voile yarns.

7. The apparatus as claimed in claim 1 wherein the tension configured is more than 12% of breaking strength of the yarn.

8. A method for direct warping of high twisted fine count yarn such as voile yarn comprising steps of: assembling predetermined number of yarn bobbins; passing the yarn ends through the comb; warping the yarns parallel on a beam; and maintaining yarn tension more than 12% of breaking strength in the individual yarn while warping.

9. The method as claimed in claim 8 wherein yarns are warped on a narrow beam to increase yarn density.

10. The method as claimed in claim 8 wherein using a comb having flexible pins to allow passage of the yams without entanglement and breakage.

11. A method as claimed in claim 8 wherein the method is carried on the apparatus claimed in the claims 1 to 7.

12. A method for dying of high twisted fine count yarns such as voile yarns on a slasher dyeing machine, said method comprising steps of: assembling predetermined number of warp beams on creels to obtain required number of the yarns in a yarn sheet; wetting, dyeing washing and drying the yarn sheet; subjecting each dried yarn in the yarn sheet to high tension in the leasing zone thereby gradually separating of each yarn in the yarn sheet before the yarn reaches to leasing rod of the leasing zone; and winding the yarns on a weaver's beam.

13. The method as claimed in claim 12 wherein each individual yarn in the yam sheet is substantially subjected t o a tension more than 20% of breaking strength.

14. The method as claimed in claim 12 wherein warp beams have high density of the high twisted fine count yarns.

15. The method as claimed in claim 12 passing the yarns through a comb having flexible pins to allow passage of the yarns without entanglement and breakage before passing winding of the dyed yarn on weaver's beam.

16. The method as claimed in claim 12 wherein the method includes a step of lubricating the yarn sheet before passing through the leasing zone.

17. The method as claimed in clam 16 wherein the lubricant is selected from the group of cationic or non-ionic lubricating.

18. The method claimed in claim 12 wherein the method includes gradually increasing of tension in the yarn sheet in each zone.

19. The method as claimed in claim 18 wherein initial tension in the yarns in the yarn sheet starts from 500 Newton.

20. The method as claimed in claim 12 wherein the dye is selected from a group of indigo dye, sulfur dyes, vat dyes, reactive dyes, and direct dyes and preferably the dye is indigo dye.

21. The method as claimed in claim 12 wherein yarn warp beam is prepared by a method of direct warping of yarn claimed in one of the claims 8 to 11 and/or by using the apparatus for direct warping as claimed in one of the claims 1 to 7.

22. A dyed voile yarn produced by the slasher dyeing method as claimed in claims 12 to 21.

23. A comb for guiding and passage of the yarn parallel to each other, comprising: a base; and plurality of flexible pins extending parallel from the base wherein the pins are free to oscillate radial direction of the yarn which allows passing the yarn without entanglement.

24. The comb as claimed in claim 23 wherein the pins are made up of flexible material such as metal and preferably stainless steel.

25. The comb as claimed in claim 23 wherein length of the comb depends upon the warp or winding width of the beam.

26. The comb as claimed in claim 23 wherein number of the flexible pins depends upon the number of the yarn ends.

27. An apparatus method for warping of yarn and method of dyeing of the yarns hereinbefore described with reference to the drawings.