WO2024084399A1

WO2024084399A1 - Method for manufacturing blended siro stretch yarn having dual core like effect and product thereof

Info

Publication number: WO2024084399A1
Application number: PCT/IB2023/060486
Authority: WO
Inventors: Ronakkumar Bharatbhai JOSHI; Gokmen KILIC; Hamit Yenici; Florian Rainer STRETZ
Original assignee: Saitex Fabrics Vietnam Co., Ltd.
Priority date: 2022-10-17
Filing date: 2023-10-17
Publication date: 2024-04-25

Abstract

A method and a system for manufacturing a blended siro stretch yarn having a dual core and an outer sheath. The dual core has a first component as a first core component of an elastane polyurethane filament and a second component is a second core component as a first staple fiber roving of a multifiber manmade staple of cellulose or polyester to form a dual yarn core. The outer sheath is a third component and is a second staple fiber roving of a cotton or blended staple fiber with a coarse count. The first staple fiber roving has a finer count and higher twist rate than the second staple fiber roving. The second component and the third component are fed to a core spun yarn attachment and roller guide and join the first component in a ring frame system forming a dual core siro stretch yarn.

Description

PATENT 1 SAITEV.P001PCT METHOD FOR MANUFACTURING BLENDED SIRO STRETCH YARN HAVING DUAL CORE LIKE EFFECT AND PRODUCT THEREOF CROSS REFERENCE TO RELATED APPLICATIONS [001] This application claims priority from US Provisional Ser. No.: 63/416,845 filed October 17, 2023, the entire contents of which are herein incorporated fully by reference. FIGURE SELECTED FOR PUBLICATION [002] Fig. 3A. BACKGROUND OF THE INVENTION Field of the Invention [003] The present invention provides a blended siro stretch yarn having a dual core effect. The present invention further provides an improved dual core stretch yarn that provides enhancements beyond conventional dual core or single core stretch yarn. Description of the Related Art [004] This section of this document introduces information about and/or from the art that may provide context for or be related to the subject matter described herein and/or claimed below. It provides background information to facilitate a better understanding of the various aspects of the present invention. This is a discussion of "related" art. That such art is related in no way implies that it is also or fully "prior" art. The related art may or may not be prior art. The discussion in this section of this document is to be read in this light, and not as admissions of prior art. [005] A blend is a mixture of two or more fibers. In yarn spinning, different PATENT 2 SAITEV.P001PCT compositions, lengths or diameters may be combined to create a blend. Blended fibers are fabrics or yarns produced with a combination of two or more types of different fibers, or yarns. Where elastane is combined with a system like this to produce yarn it is called a blended stretch yarn. [006] Elastane is a generic (unregistered) name for a lightweight synthetic fiber filament used to make stretchable clothing such as sportswear and is made up of a synthetic long chain polymer (polyether polyurea copolymer) called polyurethane (generally labeled herein as a single polyurethane filament although multiple filaments may lodge together in manufacture). SPANDEX® and LYCRA® elastane are often interchangeable terms, but only The Lycra Company LLC produces authentic LYCRA® brand spandex. LYCRA® and SPANDEX® are trademarks for polyurethane synthetic fibers; LYCRA® (US TM Reg. 5709985 to The Lycra Company LLC, of Wilmington DE and SPANDEX® owned by the Lycra Company LLC, of Wilmington DE (for fibers began as US TM Reg. 0758996 to Monsanto Chemical Co., St. Louis, MO). Conveniently, elastane may be known as Lycra® or Spandex® depending upon geographic preference (North American vs. Europe/Eastern/Asian) or industrial preference and is referred to here as an elastic polyurethane filament. REFIBRA® (US TM Reg. 6601302 a trademark of Lenzing Aktiengesellschaft Corp., of Lenzing Austria) and is a cotton staple fiber or blended cotton staple fiber provided from Lenzing^TM. As used herein Refibra® is a cotton roving of either coarse count or fine count. CREORA (US TM Reg. 7178543 is a trademark of Hyosung TNC Corporation, Seoul, Republic of Korea) is an elastane fiber. [007] T400® is a trademark (US Reg. 3278023) of The Lycra Company LLC, of Wilmington DE and represents a synthetic elasterell-p biocomponent polyester multifilament fiber, and is referred to here as a polyester filament fiber. In contrast, a polyester staple fiber is a synthetic man-made fiber made directly from purified terephthalic acid (PTA) mono ethylene glycol (MEG) or polyethylene PATENT 3 SAITEV.P001PCT terephthalate (PET) chips. And a staple fiber is a non-continuous fiber of relative short lengthy (that is not twisted together to form a long continuous yarn). [008] Roving bobbins and roving cones are built up from staple fibers from a core outwards and are used in systems for automatic transport of staple fibers through a manufacturing system. [009] Referring now to Figs. 1A, 1B, and 1C, where a conventional dual core yarn system and manufacturing method are illustrated in a dual core yarn system 100. System 100 for producing a double core (dual-core) yarn 100A is composed of three components; an (i) elastane elastic polyurethane single filament (such as Lycra®, Creora® or Inviya® I-300) on a spool 2 as fiber 2A, a (ii) a multifilament (e.g., T400® filament) on a spool 1 fed as fiber 1A that are used in a core, which is then covered by (iii) a staple sheath of a cotton or blended staple fiber on a roving bobbin 20A fed as a fiber 20A1. As shown in Fig. 1A, the first component (here the staple sheath of cotton or blended staple fiber on roving bobbin 20A) merges with the second component and third component (core) in a drifting region over respective guide rods 10A, 10B and through exemplary drifting rollers 30A, 30B, 30C forming dual core-spun yarn 100A fed to a lappet hook 50 through anti-balloon ring 60 to ring bobbin 70 on ring 80 and spindle 90. The method of continuous yarn manufacturing flow is illustrated passing from each of the respective spools 1, 2 and bobbin 20 over the respective guide rods and drifting rollers through the lappet hook, and respective structures to form a conventional dual core yarn 100A. [0010] As noted in illustrative Fig. 1B, solid filament 2A forms a portion of the core and similar round solid filament 1A forms the dual core and are surrounded by the cotton roving 20A1. As in Fig. 1C the cross-section 1C-1C in Fig. 1B notes the dual-core arrangement with two center cores (elastane filament and the multifilament). PATENT 4 SAITEV.P001PCT [0011] Referring now to Figs. 1D and 1E conventionally normal ring spin yarn is noted for comparison. As noted in Fig. 1D cotton fibers extend and are gathered and twisted forming the staple cotton roving staple. As in Fig. 1E the cross- section 1E-1D in Fig. 1D notes the cotton fiber yarn cross-section in the staple cotton roving. [0012] Detriments of the conventional dual core yarn systems as in Figs. 1A include the challenges of keeping both filaments in the core during initial and later processing and uniform fabric dyeing with indigo/vat dyes is difficult. Specifically, the twist and torque are difficult to maintain in the dual core yarns. Additionally, a left-hand twill denim is known to be softer than right-hand twill denim, and broken-twill is an alternative but is unsuccessful. Single core stretch yarn has an unacceptable growth percentage once the garment is used. [0013] Referring now to Figs. 2A, 2B, and 2C, where a conventional siro yarn system and siro manufacturing method are illustrated in a siro yarn system 200. Siro yarn is made with a process of siro spinning or Eli twist spinning. In this, the yarn is made from two staple cotton rovings fed into one draft device at the ring spinning frame of a ring spinning machine and twisted repeatedly. It is a simple- ply yarn which combines the advantages of a two-plied yarn while the twisting process for 2-ply yarns is eliminated. There are several benefits of siro spun yarns; siro yarns are available in carded, combed, carded compact and combed compact, and in other forms known to the trade. [0014] System 200 produces siro yarn 200A and is composed of two components an (i) a staple sheath of a cotton or blended staple fiber on a roving bobbin 20A fed as fiber 20B1B, and (ii) a staple sheath of a cotton or a blended staple fiber on a roving bobbin 20B fed as a fiber 20C1C each of the same count. As shown in Fig. 2A, each component (here the staple sheath of cotton or blended staple fiber on roving bobbins 20A, 20B) pass over one or more guide rods 10C through respective exemplary drifting rollers 30A, 30B, 30C forming siro yarn 200A that PATENT 5 SAITEV.P001PCT is passed through a lappet hook 60 through anti-balloon ring 60 and onto ring bobbin 70 on ring 80 on spindle 90. The method of continuous siro yarn manufacturing flow is illustrated passing from each of the respective bobbins 20A, 20B over the respective guide rods and drifting rollers through the lappet hook, and respective structures to form a conventional siro yarn 200A. [0015] As noted in illustrative Fig. 2B, cotton fiber roving from bobbin 20A merges with cotton fiber roving from bobbin 20B and are twisted generally together forming a siro yarn. As in Fig. 2C the cross-section 2C-2C in Fig. 2B notes the siro yarn is arranged with the individual cotton fibers from each roving fiber 20B1B and 20C1C are positioned together and rotate about each other but may also, in part, in contact, merge or partially mingle between each roving fiber 20B1B and 20C1C in a manner forming a yarn, but which may be picked-appart by separating each respective roving fiber. [0016] Conventionally, it is known in some fabrics that a product may experience fabric growth in a lengthwise direction or a widthwise direction or in both directions. Fabric growth is defined as the length difference between the benchmarks prior to application of a tension and after relaxation. The following conventional formula is used to calculate fabric growth percentage. [0017] Fabric Growth (as a percentage %) = (Length after washing – length before washing) x 100/Length before washing. [0018] Puckering is a bumpy, uneven surface, most often the result of incorrect sewing tension, fabric or thread instability or processing factors. This is a particular concern in denim. [0019] Conventionally, denim has a twill type structure that allows for higher fabric counters or more yarn packing for durability. Unfortunately, due to this twill structure, denim tends to be unbalanced in construction as there is a higher PATENT 6 SAITEV.P001PCT proportion of warp then weft filling yarn per inch. This increases as yarn weight increases (for durability) and further increases the problems of puckering in a garment. This is particularly concern is enhanced where denim twill type structures are over-layered at a waist seam or pocket seam. This problem is further intensified while using stretch yarn in fabrics as stretch fabrics introduce very high contractive force and reduce fabric dimensional stability. Additionally incorrect sewing tension, fabric or thread instability or other factors cause puckering. These concerns are partially addressed by using elastane in the core and T400 filament as well, but this too is a challenge in terms of unequal dying, loss of moisture absorption, and higher cost. A process using ‘broken twill’ is an alternative where the fibers are periodically broken to combat the twisting effect or fabric torque, but there are other negatives in durability. Unfortunately, single core stretch yarn has a higher growth percentage initially and after use and washing. [0020] Referring now to Fig. 4, a conventional illustration of a 3:1 twill weave noting the warp (3) and weft (1) arrangement in side-illustrations. Wherein an unfortunate result of the influence of the ratio-created by the use of a stretch fiber can cause puckering in the garment and a loss of usability and customer satisfaction. ASPECTS AND SUMMARY OF THE INVENTION [0021] According to one aspect of the present invention, there is provided a textile or blended siro stretch yarn with a dual core like effect that uses three components in the yarn for improved results. [0022] According to another aspect of the present invention there is provided a system and method for producing a blended stretch yarn using siro spinning techniques having a dual core yarn effect so as to have an alternative/substitute PATENT 7 SAITEV.P001PCT for convention dual core yarn for fabrics which addresses desired user requirements. [0023] According to another aspect of the present invention, there is provided a method and a system for manufacturing a blended siro stretch yarn having a dual core and an outer sheath. The dual core has a first component as a first core component of an elastane polyurethane filament and a second component is a second core component as a first staple fiber roving of a multifiber manmade staple of cellulose or polyester to form a dual yarn core. The outer sheath is a third component and is a second staple fiber roving of a cotton or blended staple fiber with a coarse count. The first staple fiber roving has a finer count and higher twist rate than the second staple fiber roving. The second component and the third component are fed to a core spun yarn attachment and roller guide and join the first component in a ring frame system forming a dual core siro stretch yarn. [0024] According to another aspect of the present invention there is provided a method for manufacturing a blended siro stretch yarn having a dual-core, comprising the steps of: providing a first component, as a first core component, of an elastane filament on a first spool, providing a second component, as a second core component, as a first staple fiber roving on a first roving bobbin, providing a third component, as an outer sheath, as a second staple fiber roving on second roving bobbin, passing the first component from the first spool to a filament guide roller, passing the second component from the first roving bobbin over a first guide rod and through a plurality of drafting rollers in a multi-roller drafting roller zone to a lappet hook, passing the third component from the second roving bobbin over the first guide rod and through the plurality of drafting rollers in the multi- roller drafting roller zone proximate the second component to the lappet hook, passing the first component, the second component, and the third through the lappet hook to a ring frame mechanism and a ring bobbin wherein the first core component and the second core component form the dual core of the yarn and the PATENT 8 SAITEV.P001PCT third component forms an outer sheath of the yarn. [0025] According to another aspect of the present invention there is provided a method, wherein: the second component, as the second core component, is selected from a finer count manmade staple fiber. [0026] According to another aspect of the present invention there is provided a method, wherein: the third component, as the outer sheath, is selected from a coarser count staple fiber. [0027] According to another aspect of the present invention there is provided a method, wherein: the second component as the finer count manmade staple fiber is one of a cellulose staple fiber and a polyester staple fiber. [0028] According to another aspect of the present invention there is provided a method, wherein: the third component, as the outer sheath, is a cotton staple fiber or a cotton blend staple fiber. [0029] According to another aspect of the present invention there is provided a method, wherein: the third component, as the outer sheath, as the coarser count staple fiber has a first twist multiplier, the second component, as the second core component, as the finer count staple fiber has a second twist multiplier, and the second twist multiplier is greater than the first twist multiplier. [0030] According to another aspect of the present invention there is provided a method, wherein: the first twist multiplier of the outer sheath of the third component, is approximately 1.4. [0031] According to another aspect of the present invention there is provided a method, wherein: the second twist multiplier of the second core component, is PATENT 9 SAITEV.P001PCT approximately at least 1.6. [0032] According to another aspect of the present invention there is provided a method, wherein: the third component, as the outer sheath, as the second staple fiber has a Number English (Ne) of approximately 0.8s. [0033] According to another aspect of the present invention there is provided a method, wherein: the second component, as the second core component and the first staple roving fiber has a Number English (Ne) of approximately 2.4s. [0034] According to another aspect of the present invention there is provided a method, wherein: the elastane filament is a polyurethane filament. [0035] According to another aspect of the present invention there is provided a blended siro stretch yarn product, having dual-cores, made by the method disclosed herein. [0036] According to another aspect of the present invention there is provided a system for manufacturing a blended siro stretch yarn having a dual-core, comprising: a first spool having a first component, as a first core component, of an elastane filament, a first roving bobbin, having a second component, as a second core component of a first staple fiber roving, a second roving bobbin, having a third component, as an outer sheath of a second staple fiber roving, at least one guide rod downstream from the first roving bobbin and the second roving bobbin, at least one filament guide roller downstream from the first spool, a plurality of drafting rollers downstream of the guide rod, a lappet hook and an anti-balloon ring on a ring bobbin and ring supported on a spindle downstream from each of the filament guide roller and the plurality of drafting rollers, wherein the first component extends from the first spool to the filament guide roller and to a last of the plurality of drafting rollers to the lappet hook, wherein the second PATENT 10 SAITEV.P001PCT component extends from the first roving bobbin to the guide rod and to a first of the plurality of drafting rollers to the lappet hook, wherein the third component extends from the second roving bobbin to the guide rod and to the first of the plurality of drafting rollers and proximate to the second component to the lappet hook, and a dual core siro stretch yarn extending from the lappet hook to the ring bobbin having in a core the first core component and the second core component and having as an outer sheath the third component. [0037] According to another aspect of the present invention there is provided a system wherein: the first component, as the first core component is a polyurethane filament, and the second component, as the second core component, is a finer count manmade staple fiber. [0038] According to another aspect of the present invention there is provided a system wherein: the third component, as the outer sheath, is a coarser count staple fiber. [0039] According to another aspect of the present invention there is provided a system wherein: the second component as the finer count manmade staple fiber is one of a cellulose staple fiber and a polyester staple fiber. [0040] According to another aspect of the present invention there is provided a system wherein: the third component, as the outer sheath, is a cotton staple fiber or a cotton blend staple fiber. [0041] According to another aspect of the present invention there is provided a system wherein: the third component, as the outer sheath, as the coarser count staple fiber has a first twist multiplier, the second component, as the second core component, as the finer count staple fiber has a second twist multiplier, and the second twist multiplier is greater than the first twist multiplier. PATENT 11 SAITEV.P001PCT [0042] According to another aspect of the present invention there is provided a system wherein: the first twist multiplier of the outer sheath of the third component, is approximately 1.4 and the second twist multiplier, of the second core component, is approximately at least 1.6. [0043] According to another aspect of the present invention there is provided a system wherein: the third component, as the outer sheath, as the second staple fiber has a Number English (Ne) of approximately 0.8s, and the second component, as the second core component and the first staple roving fiber has a Number English (Ne) of approximately 2.4s. [0044] According to another alternative aspect of the invention, there is provided an improvement wherein a process and resultant product address many of the concerns noted. In one optional embodiment three (3) components are fed in a ring frame (yarn manufacturing) machine. An elastane filament component, a first staple fiber roving component (either a cellulose staple fiber or a polyester staple fiber) (with a count finer than a cotton roving per a requirement to produce a long staple fiber length and desired yarn fabric), and a second cotton roving staple fiber component having a count that is coarser than a count of the cellulose staple fiber roving. In a further embodiment of the present system and method next, all three components are fed into a ring frame machine having a mechanism wherein there is a core spun yarn attachment for the elastane component and there are spiro spinning components that feed the first and second staple fiber roving components through a drafting zone. [0045] According to another alternative aspect of the present invention, there is provided a method that provides a blended siro-stretch yarn having a dual core like effect with improved color retention in dying, improved stretch effects and reduced puckering or negative assembly steps. Elastane as a filament component, PATENT 12 SAITEV.P001PCT a staple fiber component and a cotton roving component are fed to a ring frame system effective so that the elastane is fed to a core spun yarn attachment while a first manmade (cellulose or polyester) staple fiber roving and the second cotton roving are fed to siro spinning components. [0046] According to another aspect of the present invention, there is provided a method for manufacturing a blended stretch yarn having a dual-core effect, comprising the steps of: providing a set of three components to a ring frame (yarn manufacturing) machine, wherein, there is a first elastane component having a count per a required stretch in a desired yarn fabric, a second manmade ( cellulose or polyester)staple fiber roving component, with a count finer than a cotton staple fiber roving to produce a long staple fiber length and desired yarn fabric, and a third cotton roving component having a count that is coarser than a count of the cellulose staple fiber roving, feeding the first elastane and the second cellulose staple fiber into the ring frame machine having a mechanism wherein there is a core spun yarn attachment for receiving the elastane component and there are spiro spinning components that feed the second cellulose staple fiber roving component and the third cotton roving component together in a drafting zone, and operating the ring frame machine to product a blended stretch yarn. [0047] According to another aspect of the present invention, there is provided a product made by the process. [0048] The above and other aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. BRIEF DESCRIPTION OF THE DRAWINGS PATENT 13 SAITEV.P001PCT [0049] Fig. 1A is an illustrative schematic of a conventional dual core yarn system for the method producing a conventional dual core yarn. [0050] Fig. 1B is an illustrative schematic of a conventional dual core yarn produced according to the system and method of Fig. 1A. [0051] Fig. 1C is an illustrative view of a descriptive cross section along section 1C-1C in Fig. 1B noting the conventional arrangement of the outer cotton fiber roving and dual cores. [0052] Fig. 1D is an illustrative schematic of a conventional ring spun yarn with cotton fibers in a roving spun into a yarn. [0053] Fig. 1E is an illustrative view of a descriptive cross section along section 1E-1E in Fig. 1D noting the conventional cotton fiber cross section. [0054] Fig. 2A is an illustrative schematic of a conventional siro yarn system for the method of producing a conventional siro yarn. [0055] Fig. 2B is an illustrative schematic of a conventional siro yarn produced according to Fig. 2A where two roving bobbins of the same count fibers are spun together according to the system and method of Fig. 2A. [0056] Fig. 2C is an illustrative view of a descriptive cross section along section 2C-2C in Fig. 2B. [0057] Fig. 3A is an illustrative schematic of an adaptive new dual core yarn system adapted with a modified siro-type roving for a method producing a new dual core yarn. [0058] Fig. 3B is an illustrative schematic of a new dual core siro-type roving produced according to the system and method of Fig. 3A. PATENT 14 SAITEV.P001PCT [0059] Fig. 3C is an illustrative view of a descriptive cross section 3C-3C in Fig. 3B. [0060] Fig. 4 is a conventional illustrative of a 3:1 twill weave noting the warp and weft arrangement in side-illustrations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0061] Reference will now be made in detail to embodiments of the invention. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. The word ‘couple’ and similar terms do not necessarily denote direct and immediate connections, but also include connections through intermediate elements or devices. For purposes of convenience and clarity only, directional (up/down, etc.) or motional (forward/back, etc.) terms may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope in any manner. It will also be understood that other embodiments may be utilized without departing from the scope of the present invention, and that the detailed description is not to be taken in a limiting sense, and that elements may be differently positioned, or otherwise noted as in the appended claims without requirements of the written description being required thereto. [0062] Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent. [0063] Referring additionally now to Figs. 3A, 3B, and 3C, where a blended siro stretch yarn having a dual core like effect system 300 and manufacturing method PATENT 15 SAITEV.P001PCT are illustrated for to provide a blended siro stretch yarn 300A. System 300 provides a dual core (double core) yarn 300A in a new method and system, and is composed of three components; (i) a first component: an elastane elastic polyurethane single filament (such as Lycra®) on a spool 2 fed as fiber 2A as a first core portion, (ii) a second component: a multifiber manmade first stable fiber roving (a cellulose staple or a polyester staple) on a bobbin 20E fed as fiber 20E1E that has a finer count (e.g., finer roving less weight per unit length and having a higher twist then a second stable fiber roving) as a second core portion, and (iii) a third component: a second staple fiber roving of a staple sheath of a cotton or blended staple fiber on a roving bobbin 20D fed as a fiber 20D1D that has a coarser count (e.g., coarser roving as higher weight per unit length and having a lower twist than the first staple fiber roving). The first component fiber filament (first core portion) 2A is fed over the filament guide roller 40 to the lower drafting roller 30C. It will also be understood that the first component fiber filament elastane (first core portion) may be provided as a pared or two fiber filament component of twined elastane (as the first core portion) [see Table 1 below, samples 3, 4]; and in this situation, spool 2 is provided as two spools or a divided spool (discussed but not shown) with pared elastane fiber filaments (discussed but not shown) both passing over filament guide roller 40 and lower drafting roller 30C. The second component finer count manmade cellulose or polyester stable fiber (second core portion) 20E1D and the third component coarser count cotton or blended staple fiber (outer sheath over first and second core portions) 20D1D are fed over single guide rod 10D and through the drafting zone of drafting rollers 30A, 30B, and 30D forming the blended siro stretch yarn 300A fed to lappet hook 50 through anti-balloon ring 60 to ring bobbin 70 on ring 80 and spindle 90. The method of continuous yarn manufacturing flow is illustrated passing from each of the respective spool 2 and bobbins 20D, 20E over the respective guide rod and drifting rollers through the lappet hook, and respective structures to form the blended siro stretch yarn 300A according to the system and method provided. PATENT 16 SAITEV.P001PCT [0064] As noted in illustrative Fig. 3B, solid filament 2A of forms a portion of the core and grouping of the second component bundle of finer counter roving fibers (manmade cellulose or polyester staple fibers) 20E1E form another portion of the core and surrounding is the coarser count cotton or blended staple fiber 20D1D. As in Fig. 3C the cross-section 3C-3C in Fig. 3B notes the dual-core arrangement with two center cores (elastane filament and the multifilament formed from a finer counter manmade cellulose or polyester staple fiber using the modified siro yarn process). [0065] Discussion of examples, trial products, and results: [0066] As a benefit of the present invention, cellulose fiber roving (of the third component and possible second component) is easier to dye in a vat process and resultant textiles made from this can be easily dyed. A further benefit is that the density of the staple fibers (second and third components) is less than that of the first component filament and gives a desired bulkiness to yarn and resultant fabric which aids absorption of moisture. The second component, the finer counter manmade cellulose or polyester staple fiber, tends due to the factors discussed below, easily aligns with the first component core and helps to provide improved growth properties (as shown in Table 1 below). [0067] Trial products: A series of trial products were created and tested. A conventional dual core process was created and tested similarly and for comparison in the Table 1 below. A total of four (4) different fabric samples were prepared using four different yarns produced according to the proposed invention. One sample (1) was prepared with the new system and method using the same elastane first component as in conventional dual core yarn as weft (e.g., elastane provided as/by Lycra®). One sample (2) was prepared with the new system and method using another supplied elastane (e.g., elastane provided as/by Creora®). Two samples (3 and 4) were prepared with the new system and method using two PATENT 17 SAITEV.P001PCT elastanes (e.g., elastane provided as/by Creora®) of high elastane percentages in the core of the yarn. All yarns were used as weft in the resulting fabric. All fabric samples were prepared using conventional fabric article structures replacing the new inventive yarns in the weft way. Fabric samples with the new inventive yarns were dyed to check objectional faults in fabrics after dying. In the exemplary Table 1, manmade cellulose staple fibers were the second component (second core portions 1-4) but it will be understood that manmade polyester staple fiber may also serve as the second component (second core portions 1-4). [0068] Table 1 [0069] YARN Conventional NEW NEW NEW NEW CONCEPT Dual Core ¹ 2 3 4 D d, n ® D D A

PATENT 18 SAITEV.P001PCT Wf Shrinkage -12.8 -14.8 -15.0 -12.5 -14.0 (%)

[0070] General Technical Comparison and Discussion: There are three(3) components to produce the proposed yarn according to the system and method herein. [A] A coarser roving having: (i) higher weight/mass per unit length, (ii) comparatively small staple length of fiber, (iii) stiffer twist, and (iv) regular twist/inch of a normal staple fiber. [B] A finer roving having: (i) less weight/mass per unit length (than [A]), PATENT 19 SAITEV.P001PCT (ii) comparatively long staple lengths of fiber (than [A]), (iii) comparatively less stiff twist (than [A]), and (iv) a higher twist/inch of a normal staple fiber (than [A]); and [C] Elastane filament (polyurethane filament) having: (i) provided by one of the industry suppliers under their respective brand names. [0071] In a descriptive table, the comparison arrangement is as follows: [0072] Input!material!^!Conventional!Dual!Core!Vs.!New!Concept!(Table!2)! [0073] Table 2! Input!Component! Parameter! Dual!Core! New!Concept! Description! )! r! [

of a cotton yarn roving (as the number increases the physical yarn size decreases). Ne is the number of times the length of one pound of yarn can be divided by 840. As a result, as used in the tables herein the ‘Ne’ is an expression of the Number English or the size of the cotton yarn, and will be understood by those of skill in the weaving arts. [0075] Ring Frame Machine Parameter(s) (Table 3) [0076] Table 3 Parameter! Particulars! Conventional!Dual! New!concept,!system!

PATENT 20 SAITEV.P001PCT in!Drafting! Middle! 16!Kg! 16!Kg! System!for! Roller!

nt system and method there is a Fiber Migration (FM) and Twist Multiplier (TM) effect (see below) wherein a finer roving behaves like a filament and fibers of finer roving migrate in core in the process using the system 300 for the proposed method. This gives a dual core yarn like effect in the yarn 300A despite there being only a single filament elastane 2A core because the finer roving staple fiber (cellulose or polyester) behaves as and is the second core 20E1E (See Fig. 3C). [0078] Due to difference in fiber properties and the parameters of respectively the coarser roving 20D and finer rovings 20E, fiber in the finer roving 20E1E are under more tension (e.g., effective tension) than coarser roving 20D1D despite similar weights on the drafting rollers (See Table 3). This forces the fibers of the finer roving 20E1E to migrate to the core position, to align, and to remain in the core, and so serve as the second core 20E1E (Fig. 3C) as discussed herein. [0079] When both rovings 20D, 20E entered in drafting zone in ring frame, the finer roving fiber 20E1E experiences higher pressure than coarser roving fiber 20D1D because the top roll pressure (in kilograms (Kg.)) is applied the same for both but the finer roving 20E1E has a smaller number of fibers in cross section and thus a higher effective tension and finer roving fibers 20E1E migrate to core when tension is high. Further, fibers in the finer roving 20E1E have a higher twist multiplier, and longer but finer fibers. Due to this arrangement the finer PATENT 21 SAITEV.P001PCT roving fibers 20E1E are under more tension in drafting zone that aligns fibers towards the fiber strand axis (in the final yarn-process 300A fiber). Since a ring traveler weight and spindle speed are same for all fibers, the fibers of the finer roving 20E1E are under higher tension than fibers in coarser roving, and this causes the final roving fibers 20E1E to behave in a filament like manner and align with the central yarn axis during the method provided. As a result, the proposed system 300 operating the proposed dual core type method provides a siro stretch yarn having a dual core like effect. [0080] A discussion of Fiber Migration (FM): The displacement of fibers during spinning is called fiber migration. According to Textile Institute (UK), "The change in distance of a fiber or filament from the axis of a yarn during production is called fiber migration." [0081] The factors affecting on Fiber Migration (FM): The factors, or parameters, on which the fiber migration depends on are: (i) Fiber length – The higher fiber staple length the higher the fiber migration and fibers tend to move and remain the yarn core upon movement. (ii) Degree of elasticity – The higher the elasticity of a higher and finer staple the higher the tendency to migrate to the core and remain in the core during manufacturing. (iii) Stiffness – The stiffer fibers move outwards and away from the core. (iv) Fineness - Finer fibers tend to move towards the core. (v) Yarn tension – The higher the specific yarn tension during spinning the more the fibers will migrate and more rapidly. Where a fiber strand is twisted, fibers in the higher tension in the twist try to relieve tensions by migrating to the core of a fiber. (vi) Mode of Spinning - In ring spinning, fiber migration is more than conventional rotor spinning. PATENT 22 SAITEV.P001PCT (vii) The spinning geometry and processing parameters of the ring frame effect fiber migration, and these include: a. A bigger spindle / bobbin size means a bigger balloon size which results in higher spinning tension so fibers tends to move towards core to reduce the tension. b. A higher spindle speed increases tension and fiber migration on proportion. c. A higher ring traveler weight results in higher tension and increased fiber migration. d. A higher top roll pressure in drafting provides that fibers in finer roving (e.g., 20E1E) following a spiro spinning process will provide higher tension then for a similar coarser roving (e.g., 20D1D). e. A speed of fiber migration increases with an increase of the yarn twist. f. A higher roving twist places fibers in the drafting zone of a ring frame under higher tension. (viii) Strongly crimped fibers also tend to move in the sheath. [0082] A discussion of Twist Multiplier (TM): The twist multiplier is used to calculate the amount of Twist Per Inch (TPI) to be given to the cotton during spinning. This is also known as the twist factor, twist alpha, or twist coefficient and is noted as Formula 1: (1) Twist (TPI) = TM x √ Count (Ne) wherein TM is the twist multiplier and Count (Ne) is the count Number English (“Ne”) the size of a cotton yarn roving. [0083] The general guide results for addressing twist multiplier (TM) is that: (i) Lower TM results in softer yarn with comparatively less strength but a finer yarn PATENT 23 SAITEV.P001PCT or roving, (ii) Higher TM results in stiffer yarn with comparatively higher strength but with coarser yarn or roving; (iii) The longer the staple length the lower the TM required; (iv) The finer the staple length the lower the TM required. [0084] In view of the proposed method and process machinery arrangement it has been found that due to the different counts, twists, draft, tension and guiding components the elastane component and cellulose staple remain in the core of the yarn covered with the cotton roving. And as a result, the resultant product provides an improved dying with indigo/vat dyes, and the yarn/fabric made from this yarn can be similarly dyed. Additionally, the staple fiber is less than the filament fiber and gives a desired bulkiness to the yarn/fabric which also helps absorb more moisture for comfort. As the finer staple fiber 20E1E (cellulose staple or polyester staple fiber) remains in the core this additionally benefits the growth percentage properties in an improved manner. [0085] Those of skill in the weaving arts generally understand that roving as a verb may refer to a to a step before fiber is spun into a yarn. Adaptively, roving as a noun (e.g., cellulose roving or blended staple fiber roving or polyester staple fiber roving) is fiber or groups of fiber that has been processed but not yet spun into yarn and is used in a system for producing a finished yarn product for later processing. [0086] Generally, siro yarns are generically labeled (unregistered) two-fold yarns where two fiber groups are provided to a conventional ring spinning system and spun about each other forming a continuous spiral yarn. Generally, the process was provided at CSIRO in Australia (a public commonwealth scientific and industrial research organization) and thus the term. Siro spun yarns maintain two separate strands during the spinning process and this allows the strands to be easily separated. PATENT 24 SAITEV.P001PCT [0087] Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it will be apparent to those skills that the invention is not limited to those precise embodiments, and that various modifications and variations can be made in the presently disclosed system without departing from the scope or spirit of the invention. Thus, it is intended that the present disclosure covers modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims

PATENT 25 SAITEV.P001PCT WHAT IS CLAIMED IS: 1. A method for manufacturing a blended siro stretch yarn having a dual- core, comprising the steps of: providing a first component, as a first core component, of an elastane filament on a first spool; providing a second component, as a second core component, as a first staple fiber roving on a first roving bobbin; providing a third component, as an outer sheath, as a second staple fiber roving on second roving bobbin; passing said first component from said first spool to a filament guide roller; passing said second component from said first roving bobbin over a first guide rod and through a plurality of drafting rollers in a multi-roller drafting roller zone to a lappet hook; passing said third component from said second roving bobbin over said first guide rod and through said plurality of drafting rollers in said multi-roller drafting roller zone proximate said second component to said lappet hook; passing said first component, said second component, and said third through said lappet hook to a ring frame mechanism and a ring bobbin wherein said first core component and said second core component form said dual core of said yarn and said third component forms an outer sheath of said yarn. 2. The method, according to claim 1, wherein: said second component, as said second core component, is selected from a finer count manmade staple fiber. 3. The method according to claim 2, wherein: said third component, as said outer sheath, is selected from a coarser count staple fiber. PATENT 26 SAITEV.P001PCT 4. The method, according to claim 3, wherein: said second component as said finer count manmade staple fiber is one of a cellulose staple fiber and a polyester staple fiber. 5. The method, according to claim 4, wherein: said third component, as said outer sheath, is a cotton staple fiber or a cotton blend staple fiber. 6. The method, according to claim 5, wherein: said third component, as said outer sheath, as said coarser count staple fiber has a first twist multiplier; said second component, as said second core component, as said finer count staple fiber has a second twist multiplier; and said second twist multiplier is greater than said first twist multiplier. 7. The method, according to claim 6, wherein: said first twist multiplier, of said outer sheath of said third component, is approximately 1.4. 8. The method, according to claim 7, wherein: said second twist multiplier, of said second core component, is approximately at least 1.6. 9. The method, according to claim 8, wherein: the third component, as the outer sheath, as the second staple fiber has a Number English (Ne) of approximately 0.8s. 10. The method, according to claim 9, wherein: PATENT 27 SAITEV.P001PCT the second component, as said second core component and said first staple roving fiber has a Number English (Ne) of approximately 2.4s. 11. The method, according to claim 10, wherein: said elastane filament is a polyurethane filament. 12. A blended siro stretch yarn product, having dual-cores, made by the method according to claim 1. 13. A system for manufacturing a blended siro stretch yarn having a dual-core, comprising: a first spool having a first component, as a first core component, of an elastane filament; a first roving bobbin, having a second component, as a second core component of a first staple fiber roving; a second roving bobbin, having a third component, as an outer sheath of a second staple fiber roving; at least one guide rod downstream from said first roving bobbin and said second roving bobbin; at least one filament guide roller downstream from said first spool; a plurality of drafting rollers down stream of said guide rod; a lappet hook and an anti-balloon ring on a ring bobbin and ring supported on a spindle downstream from each of said filament guide roller and said plurality of drafting rollers; wherein said first component extends from said first spool to said filament guide roller and to a last of said plurality of drafting rollers to said lappet hook; wherein said second component extends from said first roving bobbin to said guide rod and to a first of said plurality of drafting rollers to said lappet hook; PATENT 28 SAITEV.P001PCT wherein said third component extends from said second roving bobbin to said guide rod and to said first of said plurality of drafting rollers and proximate to said second component to said lappet hook; and a dual core siro stretch yarn extending from said lappet hook to said ring bobbin having in a core said first core component and said second core component and having as an outer sheath said third component. 14. The system, according to claim 13, wherein: said first component, as said first core component is a polyurethane filament; and said second component, as said second core component, is a finer count manmade staple fiber. 15. The system, according to claim 14, wherein: said third component, as said outer sheath, is a coarser count staple fiber. 16. The system, according to claim 15, wherein: said second component as said finer count manmade staple fiber is one of a cellulose staple fiber and a polyester staple fiber. 17. The system, according to claim 16, wherein: said third component, as said outer sheath, is a cotton staple fiber or a cotton blend staple fiber. 18. The system, according to claim 17, wherein: said third component, as said outer sheath, as said coarser count staple fiber has a first twist multiplier; said second component, as said second core component, as said finer count staple fiber has a second twist multiplier; and said second twist multiplier is greater than said first twist multiplier. PATENT 29 SAITEV.P001PCT 19. The system, according to claim 18, wherein: said first twist multiplier, of said outer sheath of said third component, is approximately 1.4 and said second twist multiplier, of said second core component, is approximately at least 1.6. 20. The system, according to claim 19, wherein: the third component, as the outer sheath, as the second staple fiber has a Number English (Ne) of approximately 0.8s; and the second component, as said second core component and said first staple roving fiber has a Number English (Ne) of approximately 2.4s.