EP3642410A1 - Process and apparatus for production of yarn having longitudinally variable dye uptake - Google Patents

Abstract

Apparatuses and processes for producing yarn having longitudinally variable dye uptake and well as yarns having longitudinally variable dye uptake and articles prepared from these yarns are provided.

Description

Process and Apparatus for Production of Yarn having Longitudinally Variable Dye

Uptake

[001] This patent application claims the benefit of priority from U.S. Provisional Application Serial No. 62/521,760, filed June 19, 2017, teachings of which are herein incorporated by reference in their entirety.

FIELD OF THE INVENTION

[002] The present invention relates to an apparatus and process for producing yarn having longitudinally variable dye uptake and well as yarns having longitudinally variable dye uptake and articles prepared from these yarns.

BACKGROUND OF THE INVENTION

[003] In most textile dyeing processes, the objective is to obtain a uniform level dyeing throughout the fabric. Fabrics with a nonuniform dyed appearance are traditionally regarded as inferior or defective. Numerous techniques, compositions and additives have been developed with the aim of achieving consistent level dyeing of textiles.

[004] However, for certain styling effects, a controlled non-levelness of dyeing may be desirable. For example, a popular styling effect in apparel fabrics is a nonuniform mottled or "heather" look.

[005] Typically, this heather look has been achieved by cross dyeing, for example, by blending two or more different kinds of fibers which receive dye differently. For example, natural or cellulosic fibers may be blended with synthetic fibers and cross dyed with different classes of dyestuffs to achieve the heather look.

[006] U.S. Patent 5,667,533 discloses a method for producing heather dyed fabric. The process involves impregnating a textile fabric with an aqueous pretreatment composition comprising a fiber reactive cationic compound. The impregnated fabric is then aged in a moistened state for about 4 to 24 hours to allow the fiber reactive cationic compound to react with the fibers of the fabric. The fabric is then rinsed to remove unreacted cationic compound. Subsequently, the fabric is immersed in an aqueous bath at a pH of less than 7 and dyestuffs are gradually introduced to the bath over a period of at least 15 minutes. The dyestuffs are fully exhausted onto the fabric and result in the fabric having a heather-like dyed appearance.

[007] There remains a need for efficient methods for producing heather yarn and articles thereof. SUMMARY OF THE INVENTION

[008] The present disclosure relates to processes and apparatuses for producing yarn having longitudinally variable dye uptake. Also disclosed are yarn and articles, including carpets, formed from these processes or apparatuses.

[009] Accordingly, an aspect of the present invention relates to a method for producing yarn having longitudinally variable dye uptake. In this method, a provided yarn is partially wetted to provide discontinuous wet and dry regions along the length of the yarn. The method further comprises heating the discontinuously wetted yarn to impart longitudinally variable dye uptake to the yarn. Various yarn having longitudinally variable dye uptake can be produced including but not limited to twisted yarn, textured twisted yarn, bulked textured twisted yarn, yarn comprising continuous filaments and yarn comprising staple. Yarns may comprise a dyeable polymer such as, but not limited to, polyamides, polyesters, polyolefms and copolymers and blends thereof.

[0010] Another aspect of the present invention relates to an apparatus for producing yarn having longitudinally variable dye uptake. The apparatus comprises a fluid dispenser system for discontinuously wetting yarn and a guide for transferring the discontinuously wetted yarn to a heater. In some embodiments, the apparatus further comprises a heater to heat the discontinuously wetted yarn.

[0011] Another aspect of the present invention relates to yarn of uniform composition and cross-sectional size having controlled variable dye uptake along its length.

[0012] Yet another aspect of the present invention relates to articles, at least a portion of which are formed from yarn of uniform composition and cross-sectional size having controlled variable dye uptake along its length. In one nonlimiting embodiment, the article is carpet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 depicts a nonlimiting embodiment of an apparatus of the present invention used in Example 1.

[0014] FIG. 2 depicts another nonlimiting embodiment of an apparatus of the present invention used in Example 2.

DETAILED DESCRIPTION OF THE INVENTION

[0015] All publications and patents cited in this specification are herein incorporated by reference as if each individual publication or patent were specifically and individually indicated to be incorporated by reference and are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The citation of any publication is for its disclosure prior to the filing date and should not be construed as an admission that the present disclosure is not entitled to antedate such publication by virtue of prior disclosure. Further, the dates of publication provided could be different from the actual publication dates that may need to be independently confirmed.

[0016] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features that may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible.

[0017] Embodiments of the present disclosure will employ, unless otherwise indicated, techniques of chemistry, polymer physics, fabrics, textiles, and the like, which are within the skill of the art. Such techniques are fully explained in the literature.

[0018] It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a support" includes a plurality of supports. In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings unless a contrary intention is apparent.

The inventors herein have developed an efficient process for controlled non-levelness of dyeing of yarn which is aesthetically appealing when used in articles such as, but in no way limited to, carpet. Further, carpets produced from this yarn maintain the necessary floor performance for residential applications. As will be understood by the skilled artisan upon reading this disclosure, while yarn produced in accordance with the methods and apparatuses described herein is exemplified for use in carpet, such yarn with controlled variable dye uptake will be useful in various textile applications including, but in no way limited to, apparel, upholstery, bedding, curtains and drapes and other fabrics.

The present invention provides a method for producing yarn having longitudinally variable dye uptake. The method comprises providing a yarn which is partially wetted to provide discontinuous wet and dry regions along the length of the yarn. The discontinuously wetted yarn is then heated to impart longitudinally variable dye uptake to the yarn. Various yarn having longitudinally variable dye uptake can be produced with this process including, but in no way limited to twisted yarn, textured twisted yarn and bulked, testured twisted yarn. Further, yarn may comprise continuous filaments or staple.

[0019] Yarn having longitudinally variable dye uptake produced in accordance with the present invention comprises a dyeable polymer. Nonlimiting examples of dyeable polymers include polyamides, polyesters, polyolefins and copolymers and blends thereof. In one nonlimiting embodiment, the polyamide is nylon, silk or wool. In one nonlimiting embodiment, the nylon is the product of a condensation reaction. Nonlimiting examples of polyamide fibers include fibers comprising nylon 5,6; nylon 6/6; nylon 6; nylon 7; nylon 11; nylon 12; nylon 6/10;, nylon 6/12; nylon DT; nylon 6T; nylon 61; and blends or copolymers thereof. Nonlimiting examples of polyolefm fibers include fibers comprising polypropylene. Nonlimiting examples of polyester fibers include fibers comprising polyethylene

terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid (PLA) and blends or copolymers thereof. In one nonlimiting embodiment, the yarn is formed from nylon 6,6 or nylon 6 polymer.

[0020] In one nonlimiting embodiment, the yarn used is made from acid dyeable nylon polymer. As used herein, acid dyeable nylon polymer are nylon polymers having available sites receptive to acid dyes. In one nonlimiting embodiment, the acid, or white dyeable nylon polymer comprises nylon polymer having basic amine moieties.

[0021] In another nonlimiting embodiment, the yarn is made from cationic dyeable nylon polymer.

[0022] Further, as will be understood by the skilled artisan upon reading this disclosure, other polymeric fibers modified to include dyeable sites can be used in this process and are encompassed by the present invention.

Does this work for regular acid dye or only for large, structure-sensitive dyes? Another way of asking this question is: "Is the selection of dye or method of dyeing critical to making the invention work?"

Are leveling or reserving dyes required? [0023] In one nonlimiting embodiment, the wetting step is performed using a fluid dispensing system. Nonlimiting examples of fluid dispensing systems which can be used to provide discontinuous wet and dry regions along the length of a yarn include air-powered dispensers, dispense valve systems, automated dispensers, dispensing syringe barrels, dispensing pistons, dispensing cartridges, peristaltic pumps, mechanical pumps, manual pumps, syringes, volumetric dispensers, gravimetric dispensers, and squirt guns.

[0024] In one nonlimiting embodiment, the yarn is wetted for a period of about 0.5 to about 7 seconds.

[0025] In one nonlimiting embodiment, the wetting step is performed under hot air at a temperature in the range from about 110°C to about 150°C.

[0026] Once discontinuously wetted, the yarn is guided to a heater. Preferred is that the yarn remains discontinuously wetted upon entering the heater step.

[0027] Heating of the yarn can be performed by any method of heat transfer.

Nonlimiting examples include radiant, convective and conductive heat transfer.

[0028] In one nonlimiting embodiment, the yarn is heated by radiant heating such as irradiation with microwave or infrared energy.

[0029] Alternatively, one of the general heat-setting methods used in bulked continuous fiber (BCF) productions can be used. These include autoclave (steam and pressure in a batch process), SUPERBA (continuous steam and pressure; American Superba, Inc (Dalton, GA)) and SUESSEN (dry heat; Power-Heat-Set of America (Dalton, GA)).

[0030] The autoclave process uses steam in a pressure vessel. Time and temperature of the autoclave cycle provides the desired properties that gives the yarns a "memory" for crush resistance to normal foot traffic, a desirable visual appearance, and characteristics of other desirable properties.

[0031] The other types of heating-setting methods are typically used in continuous heat- setting machines.

[0032] SUPERBA (continuous steam and pressure; American Superba, Inc (Dalton, GA)) uses pressurized steam (i.e., saturated or near saturated steam) and the most common pressurized steam heat-setting machine is referred to as a SUPERBA machine made by American Superba, Inc (Dalton, GA)). A SUPERBA heat-setting machine generally operates with a maximum temperature of 154^°C, typically in the temperature range from 120^°C to 140°C, and with a maximum pressure of 65.26 psi, typically in the pressure range from 22 to 37 psi. [0033] The most common hot air atmospheric pressure heat-setting machine is referred to as a SUES SEN machine, and is made presently by Power Heat Set of Dalton, GA. An exemplary SUESSEN heat setting machine operates in the temperature range of 160°C to 210^°C. The. SUESSEN machine is heated either by a non-direct thermal fluid texturing media or by electric resistance rods.

[0034] The crystalline structure of heat-set yarns and the end use performance of the finished carpets produced from heat-set yarns primarily depend on the heat-setting method used in producing the yarn. It is well understood that the heat-setting method used has a great impact on nylon carpet stain performances. White, or acid dyeable nylon carpets made from acid dyeable polymer, and heat-set using pressurized steam treatment, or saturated steam, have long-lived stain resistance. Currently, the majority of heat-setting machines used are pressurized steam heat-setting machines, such as Superba RTM machines.

[0035] In one nonlimiting embodiment, the discontinuously wetted yarn is heated by direct contact with steam. In this nonlimiting embodiment, the steam may be superheated or saturated. In one nonlimiting embodiment, the discontinuously wetted yarn is heated with saturated steam at a temperature in the range from about 120°C to about 160°C. In this embodiment, it is preferred that the discontinuously wetted yarn be heated for a period of about 25 to about 60 seconds.

[0036] Without being bound to any particular theory, it is believed that use of heat on the discontinuously wetted yarn prevents the polymer crystal structure in portions of the yarns from opening and becoming more susceptible to acid stains. Through undue

experimentation, the inventors herein have discovered that using the process disclosed herein results in yarn having longitudinally variable dye uptake useful in creating new styling effects through dyeability differences, without any diminishing performance in end use.

[0037] Also provided by the present invention are apparatuses for producing yarn having longitudinally variable dye uptake.

[0038] In simplest form, the apparatus comprises a fluid dispenser system 3 for .

discontinuously wetting yarn and a guide 5 for transferring the discontinuously wetted yarn to a heater 4.

[0039] Suitable fluid dispenser system may be any apparatus known to those skilled in the art that can discontinuously wet yarn to leave both dry and wet regions on the yarn.

Nonlimiting examples of suitable fluid dispenser systems include those that utilize mechanical or manual fluid dispensation, including air-powered dispensers, dispense valve systems, automated dispensers, dispensing syringe barrels, dispensing pistons, dispensing cartridges, peristaltic pumps, syringes, volumetric dispensers, gravimetric dispensers, and squirt guns. In one nonlimiting embodiment, the fluid dispenser system is capable of treating the yarn for a period of about 0.5 second or greater. In one nonlimiting embodiment, the fluid dispenser systems is capable of treating the yarn for a period of about 0.5 to about 7 seconds. In one nonlimiting embodiment, the fluid dispensing system is capable of discontinuously wetting the yarn under hot air at a temperature in the range from about 110°C to about 150°C.

[0040] In some embodiments, the apparatus further comprises the heater 4 to heat the discontinuously wetted yarn. Heating of the yarn can be performed by any means of heat transfer. Nonlimiting examples of heaters include those providing radiant, convective or conductive heat transfer. In one nonlimiting embodiment, the heater may comprise a microwave or an infrared energy. In one nonlimiting embodiment, the heater provides direct contact with steam. Heaters used in heat-setting methods used in bulked continuous fiber (BCF) productions can also be used. These include autoclave (steam and pressure in a batch process), SUPERB A (continuous steam and pressure; American Superba, Inc (Dalton, GA)) and SUESSEN (dry heat; Power-Heat-Set of America (Dalton, GA)).

[0041] For some embodiments, as described in Examples 1 and 2, the apparatus may further comprise a prebulker 2, a yarn coiler 6 and/or a staffer box 7. In one nonlimiting embodiment, the prebulker is a high efficiency prebulker (HEP).

[0042] The present invention also relates to yarn of uniform composition and cross- sectional size having controlled variable dye uptake along its length and articles at least a portion of which comprise the yarn. In one nonlimiting embodiment, the article is a carpet, at least a portion of which is formed from the yarn treated by any of the processes and/or apparatuses disclosed herein. As shown in Examples 1 and 2, carpet produced via processes and apparatuses disclosed herein exhibit differential dyeability that appears to be on the order of two shades, within the same threadline of yarn.

[0043] As will be understood by the skilled artisan upon reading this disclosure, while yarn produced in accordance with the methods and apparatuses described herein is exemplified for use in carpet, such yarn with controlled variable dye uptake will be useful in various textile applications including, but in no way limited to, apparel, upholstery, bedding, curtains and drapes and other fabrics. [0044] The following section provides further illustration of the processes and apparatuses of this invention. These working examples are illustrative only and are not intended to limit the scope of the invention in any way.

Examples

Comparative Example 1

[0045] A 920 denier white dyeable BCF yarn (920-426AS, manufactured by INVISTA S.a r.l.) made from nylon 6,6 polymer was first converted into 6.0 twist per inch cable twisted yarns, and subsequently heat-set on Superba using standard process settings including a maximum temperature of 154^°C, typically in the temperature range from 120°C to 140°C, and with a maximum pressure of 65.26 psi, typically in the pressure range from 22 to 37 psi. . The cable twisted and heatset yarns were converted into 32 oz cut pile carpets, and coated with latex to secure tufts using the state of the art latexing process.

[0046] This item was tested for aesthetic appeal and found to be uniform in color, and overall not altogether remarkable.

Example 1

[0047] A 920 denier white dyeable BCF yarn (920-426AS, by INVISTA S.a r.l.), made from medium acid dyeable nylon 6,6 polymer was first converted into 6.0 twist per inch cable twisted yarns, and fed to a SUPERBA heat-setting tunnel. Water was trickled onto the yarn in between the high efficiency prebulker (HEP), and the heat setting tunnel entrance. The CBS (central blower system) was not utilized at the tunnel, where the yarn was heat-set at 130° C. The cable twisted and heat-set yarns were converted into 32 oz carpets, and coated with latex to secure tufts using the state of the art latexing process.

[0048] This item was examined for aesthetic appeal and found to have striations and nonuniform dyeing along the length of the carpet pile, which provided a pleasing effect to the naked eye. The differential dyeability appeared to be on the order of two shades within the same threadline of yarn.

Example 2

[0049] A 920 denier white dyeable BCF yarn (920-426AS, by INVISTA S.a r.l), made from medium acid dyeable nylon 6,6 polymer was first converted into 6.0 twist per inch cable twisted yarns, then fed first through a stuffer box, then to a prebulker. After passing through the prebulker, water was applied by spraying onto the yarn in between the HEP, and the SUPERB A heat setting tunnel entrance. The CBS (central blower system) was not utilized at the tunnel, where the yarn was heatset at 130° C. The cable twisted and heatset yarns were converted into 32 oz carpets, and coated with latex to secure tufts using the state of the art latexing process.

[0050] This item was examined for aesthetic appeal and found to have striations and nonuniform dyeing along the length of the carpet pile, which provided a pleasing effect to the naked eye. The differential dyeability appeared to be on the order of two shades within the same threadline of yarn.

Claims

1. A method for producing yarn having longitudinally variable dye uptake comprising: a) providing a yarn;

b) partially wetting the yarn to provide discontinuous wet and dry regions along the length of the yarn;

c) heating the discontinuously wetted yarn to impart longitudinally variable dye uptake to the yarn.

2. The process of claim 1 wherein the yarn is twisted.

3. The process of claim 2 where the twisted yarn is a textured twisted yarn.

4. The process of claim 3 wherein the textured twisted yarn is bulked.

5. The process of any one of the preceding claims wherein the yarn comprises continuous filaments.

6. The process of any one of claims 1 through 4 wherein the yarn comprises staple.

7. The process of any one of the preceding claims wherein the heating is performed by radiant, convective or conductive heat transfer.

8. The process of claim 7 wherein the radiant heating comprises irradiating with microwave or infrared energy.

9. The process of claim 7 wherein the heating comprises direct contact with steam.

10. The process of 9 wherein the steam is superheated or saturated.

11. The process of any one of the preceding claims wherein the yarn remains discontinuously wetted upon entering the heating step.

12. The process of any one of the preceding claims wherein the yarn comprises a dyeable polymer.

13. The process of claim 12 wherein the dyeable polymer is selected from polyamides, polyesters, polyolefms and copolymers and blends thereof.

14. The process of claim 13 wherein the polyamide is selected from nylon, silk and wool.

15. The process of 14 wherein the nylon is the product of a condensation reaction.

16. The process of any one of the preceding claims wherein wetting step (b) is performed using a fluid dispensing system.

17. The process of claim 16 wherein the fluid dispensing system is selected from the group consisting of air-powered dispensers, dispense valve systems, automated dispensers, dispensing syringe barrels, dispensing pistons, dispensing cartridges, peristaltic pumps, mechanical pumps, manual pumps, syringes, volumetric dispensers, gravimetric dispensers, and squirt guns.

18. The process of any one of the preceding claims wherein the yarn is wetted in step (b) for a period of about 0.5 to about 7 seconds.

19. The process of any one of the preceding claims wherein wetting step (b) is performed under hot air at a temperature in the range from about 110°C to about 150°C.

20. The process of any one of the preceding claims wherein step (c) is achieved with saturated steam at a temperature in the range from about 120°C to about 160°C.

21. The process of any one of the preceding claims wherein step (c) is performed for a period of about 25 to about 60 seconds.

22. An apparatus for producing yarn having longitudinally variable dye uptake, said apparatus comprising a fluid dispenser system for discontinuously wetting yarn and a guide for transferring the discontinuously wetted yarn to a heater.

23. The apparatus of claim 22 further comprising a heater to heat the

discontinuously wetted yarn.

24. The apparatus of claim 22 wherein the fluid dispenser system is selected from the group consisting of air-powered dispensers, dispense valve systems, automated dispensers, dispensing syringe barrels, dispensing pistons, dispensing cartridges, peristaltic pumps, mechanical pumps, manual pumps, syringes, volumetric dispensers, gravimetric dispensers and squirt guns.

25. Yarn of uniform composition and cross-sectional size having controlled variable dye uptake along its length.

26. An article at least a portion of which is formed from yarn of claim 25.

27. A carpet at least a portion of which is formed from yarn of claim 25.