KR20140101851A - Stretchable and dimensionally stable woven fabric made from polytrimethylene terephthalate based core spun yarns - Google Patents

Abstract

Wherein the core is an extensible filament and is surrounded by a sheath of polytrimethylene terephthalate based staple fiber in combination with a second staple fiber. Fabrics are made using core yarns. Fabrics made from core yarns are highly stretchable, have high dimensional stability, low growth, and high recoverability.

Description

STRETCHABLE AND DIMENSIONALLY STABLE WOVEN FABRIC MADE FROM POLYTRIMETHYLENE TEREPHTHALATE BASED CORE SPUN YARNS Made from Polytrimethylene Terephthalate Core Spun Yarn [0002]

This application claims the benefit of Indian Patent Application No. 3626 / DEL / 2011, filed December 13, 2011, which is incorporated herein by reference.

The present invention relates to a polytrimethylene terephthalate (PTT) based core yarn wherein the core of the yarn comprises a stretchable filament and the sheath comprises polytrimethylene terephthalate based staple fibers.

The present invention further relates to a highly stretchable fabric exhibiting high recovery and low growth wherein the PTT based core yarns are present in a weft direction.

The garment industry has a constant need for a better and newer variety of fabrics to meet the unfulfilled evolving needs of discerning consumers. One of the needs of the apparel industry is the need for an extensible fabric with a comfortable feel.

Core spun yarns (CSY) are widely used in the manufacture of denim, bottom, and stretch fabrics used in the manufacture of shirts. CSY's known in the art typically have cotton, polyethylene terephthalate (PET), viscose, nylon, or blends thereof as their sheath component with Lycra or spandex filaments forming the core. The CSY garment has a stretch level in the range of 7 to 35%, depending on the percentage of spandex in the core. Fabrics made to a stretch level of 8 to 15% are referred to as comfort stretch fabrics. A fabric having a stretch level of 16 to 35% is referred to as a super stretch fabric. Fabrics having a stretch level of 35% have a high spandex percentage (about 9-10%). This results in undesirable high growth potential or low recovery potential. Fabrics with an elongation level of almost 15% have a growth rate of almost 5% and a recovery level of only 70%. This causes baggy formation and dimensional instability of the final garment after some use.

WO 2008130563 discloses an elastic composite material for use as warp and weft yarns for woven fabrics comprising a filamentary core comprising a resilient performance filament (s) and an inelastic control filament (s), and a fibrous sheath comprising a spinous staple fiber The yarn is started.

There is a need for a market for fabrics with high stretch properties and high dimensional stability with low growth and high recovery. These properties will generally provide fabrics that are more durable and provide superior levels of comfort and aesthetics.

There is described herein a core yarn comprising a core comprising extensible filaments surrounded by a sheath comprising polytrimethylene terephthalate based staple fibers in combination with second staple fibers.

Also disclosed herein is a fabric comprising the core yarns.

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Figure 1 is a schematic representation of core yarn fabrication.
2,
Figure 2 is a schematic representation of fabric (denim) fabrication using a core yarn.
DETAILED DESCRIPTION OF THE INVENTION [
Fabrics made from core yarns (CSY) are described herein. CSY comprising polytrimethylene terephthalate based staple fibers is also described. CSY is a circular cylinder composed of an inner core yarn surrounded by staple fibers. Thus, the surrounding staple fibers form a CSY sheath. The core yarns combine the strength and / or elongation of the core yarn with the features of the staple fiber sheath forming the surface.
The fabric is a stretchy, dimensionally stable woven fabric that has good stretch recoverability and low stretchability combined with high stretch properties.
The fabrics also deal with realistic aspects of growth in highly fabricated heavy fabrics such as denim, bottom fabrics, and suit fabrics in addition to the above qualities.
As used herein, the terms "polytrimethylene terephthalate" or "PTT" are used interchangeably. Polytrimethylene terephthalate is bio-based, bio-based, or petroleum based.
As used herein, the term "staple fibers" refers to fibers of standardized length, unlike continuous fibers known as filaments. The staple fiber is cut to a specific length from the continuous filament fiber. Typically, the staple fibers are cut to a length ranging from 2.5 to 1.3 cm (1 to 1/2 inch) to a length of 20.3 cm (8 inches).
The core yarn has an inner core that includes a stretch filament and is surrounded by a sheath of polytrimethylene terephthalate staple fiber in combination with a second staple fiber.
The extensible filaments may be spandex filaments. Spandex is a polyurethane-polyurea copolymer known for its elasticity and stretchability. Continuous spandex filaments provide stretching to CSY.
As used herein, the term "polytrimethylene terephthalate staple fiber" refers to a staple fiber that is 100% polytrimethylene terephthalate (PTT) staple fiber, or nylon, styrene, polyethylene terephthalate (PET) Lt; RTI ID = 0.0 > PTT. ≪ / RTI >
In one embodiment of the present invention, the PTT staple fibers are combined with second staple fibers selected from cotton, polyester, viscose, nylon, modal, tencel, wool, or combinations thereof. In one embodiment, the polytrimethylene terephthalate-based staple fibers are combined with cotton and viscose. These form the sheath of the core spun yarn.
In another embodiment, the polytrimethylene terephthalate content in the outer sheath is 10% to 60%, or 25% to 50%, or 35% to 40%. The percentage of polytrimethylene terephthalate used in the sheath woven contributes to the stretch recovery properties in CSY.
A "woven fabric" is used to define a fabric produced by interlacing two sets of yarns, called warp (weft) and weft (weft). The warp advances in the longitudinal direction within the fabric and the warp advances in the width direction within the fabric. The fabric is woven by techniques known in the art, such as plain weave, water weave, and twill weave.
The cores of CSY may be extensible fibers or filaments selected from the group of spandex and LYCRA (R). In one embodiment of the invention, the percentage of extensible fibers in the yarn was in the range of 2% to 10%, or 5% to 8%, or 5% to 6%.
In one embodiment of the invention, the sheath comprises a weft that is CSY as described herein and the warp is selected from cotton, nylon, polyester (e.g., PET, PTT), wool, viscose, Staple fiber cords.
As used herein, the term "extensibility " refers to the property of a fabric that extends to a predetermined percentage length when applying a fixed amount of load. Fabrics with good stretch properties are defined by the ability of the fabric to extend to its maximum and recover with minimal growth potential on the fabric after removal of the applied load. An example of good stretching properties in fabrics is approximately 15% stretching. Such fabrics are referred to as "comfort-stretch" fabrics. The elongation and growth properties are measured using standard ASTM international procedures (see Table 1).
One aspect of the invention is a fabric comprised of a core yarn, wherein the inner core of the core yarn is surrounded by a sheath of polytrimethylene terephthalate-based staple fibers comprising stretch filaments and combined with the second fibers.
The fabrics of the present invention have a high "dimensional stability ", meaning that they have maximum recoverability and minimal growth remaining in the fabric after stretching is released.
The term " stretch recoverability " as used herein refers to the ability of the fabric to extend to its maximum and recover, leaving a minimum amount of growth on the fabric after removal of the applied load. Acceptable draw-up resilience has a draw-up resilience of greater than 70%. Greater than 70% recoverability in the fabric and less than 2.5% growth make it a dimensionally stable fabric. The stretch recoverability and growth characteristics of the fabric remain constant throughout the life of the fabric.
Other properties of the fabric, such as weight, tensile strength, and tear strength, were also described using standard ASTM international procedures (see Table 1).
ASTM refers to the American Society for Testing and Materials (ASTM International, West Conshohocken, Pennsylvania). ASTM International annually publishes the Annual Book of ASTM Standards.
In one embodiment, the fabric of the present invention has a stretch recoverability in the range of 75 to 95%, or 80 to 95%.
In another embodiment, the fabric of the present invention has a growth of less than 2.5%, or less than 2.3%.
In addition to high extensibility (greater than 15%), high resilience (greater than 70%), and low growth (less than 3%), the fabrics of the present invention have good feel to wear, good ultraviolet protection, The PTT sheath in the yarn provides acid resistance and alkali resistance during washing.
The fabrics of the present invention are selected from plain fabrics, denim fabrics, under fabrics, shirt fabrics, post-fabrics, printed fabrics, checked fabrics, and striped fabrics.
The fabrics described herein can be used in the manufacture of sheet material, such as, for example, garments, bed sheets, furnishing, or upholstery.
One aspect of the invention is a method of making a core yarn, wherein the sheath is bicomponent fiber comprising PTT and cotton staple fibers, the process comprising the steps of:
(a) a blow-room process for cotton staple fibers;
(b) carding for cotton staple fibers;
(c) sliver lapping;
(d) ribbon lapping, wrap formation of cotton staple fibers;
(e) combing of cotton staple fibers;
(f) opening of the PTT-based fibers and cotton staple fibers obtained from the coaming step;
(g) mixing of two fibers;
(h) Blow-room process;
(i) carding;
(j) drawing;
(k) roving;
(l) yarn manufacture;
(m) winding; And
(n) conditioning.
Steps (a) to (e) are applied to cotton staple fibers. After coaming of the cotton staple fibers, the cotton fibers are mixed with the PTT fibers and process steps (f) to (n) as described above are applied.
The term " blow-room process "refers to the process of processing the fibers after opening and mixing in a" blow-room line ". The blow-room line consists of a number of machines that are used continuously to open and clean cotton fibers. About 40% to 70% of the trash is removed from the blow-room section. The objects of the blow-room (cotton and PTT staple fibers) are cleaned after opening, where the fibers are opened from a larger tuft size (in hundreds of grams) to a smaller tuft size (in mgs). Thereafter, cleaning is carried out to remove contaminants, dust, broken seeds, broken leaves, and other unwanted materials from the fibers. In order to produce good quality yarns and to reduce manufacturing, both processes involve mixing and blending. Followed by a lap or fleece formation where the open and cleaned fibers are converted to a sheet form having a clear width and length (referred to as a wrap), or in modern systems such sheets are fed directly to the carding machine To form a fleece.
The term "carding " refers to a process in which the fiber bundles are unwound with individual fibers and the fibers are individualized and then arranged in a parallel direction. It also removes waste and other foreign matter and fibers that are not acceptable for manufacture. Wool, waste silk, and synthetic staple fibers by a carding machine consisting of a moving conveyor belt with a fine wire brush and revolving cylinder. The material delivered from the carding machine is referred to as a sliver or card sliver.
The carding process opens up the collected mass of fibers so that they become individual fibers. However, the fibers in the card sliver are not fully aligned or oriented on the fiber axis. Some fibers are randomly placed within the sliver. Thus, the card sliver is provided with at least two drafting processes before it goes to the next machine. In this process, the sliver passes between sets of rollers operated at different speeds, with each subsequent pair rotating faster than the previous pair such that the fibers are pulled in the longitudinal direction. These two drafting operations can also be accomplished by a sliver wrap and ribbon wrap machine. In order to improve the uniformity of the sliver, a process called doubling is applied to the sliver. Doubling is a process of combining multiple slivers. By such a process, the thin and thick places existing in the sliver can be even. Within the sliver wrap machine, 16 to 20 card slivers are creased for the sifting operation and passed through the feed table to the 3 pairs of drafting rollers. The drafted sliver is then sent to two pairs of calender rollers which compress the sliver material. This drawn and compressed sliver material, called a wrap, is wound on the spool. This process is known as "wrap formation ".
"Coaming" is an additional fiber sorting operation performed on very fine yarns intended for finer fabrics. (From this machined sliver without further purification, an inexpensive, more coarse fabric is produced.) Apply a comb with combs to the sliver from the combing to separate the shorter fibers, called the noils, Align to a higher level of parallelism. The generated strand is called a comb sliver. The comb sliver uses its long fibers to provide a softer, more even yarn.
The term "drawing" refers to a process (after carding) of combining several slivers into one strand that is drawn longer and finer. The sliver from the carding machine has a high mass / length variation along its length. In order to minimize this, the doubling and drafting process is carried out in the draw frame machine. There are typically two such drawing processes to reduce the mass / length variation in the sliver to a minimum level and to orient the fibers along the length direction. The first drawing process is called a breaker drawing and the second drawing process is called a finisher drawing. The drawing frame has several pairs of rollers through which the sliver passes. Each subsequent roller pair is operated at a higher speed than the previous pair so that the sliver is pulled longer and thinner as the sliver moves through the drawing frame. Repeat the work through several steps.
The sliver transferred from the finisher draw frame has a minimum mass / length variation and the fibers oriented toward the strand axis contribute to the tensile properties. However, the linear density of the sliver is approximately 140 times the required final yarn. It is necessary to further reduce it to the required line density of yarn. This can be done in an additional step of drafting and is performed in a two-step drafting process, a speed frame machine and a ring frame machine. This two-step drafting process is recommended, since the drafting in a single step leads to the introduction of high mass / length variations. However, as the number of fibers in the sliver continues to decrease, the fibers need to be fixed to each other in a continuous fashion and need to have strength so that the fibers can be processed on the next machine. In order to impart strength to the fiber fleece, it is provided with a partial twist in the speed frame machine. The entire process of partial drafting and twisting is referred to as a roving preparation. By this drafting operation, the sliver becomes finer and the resulting product is called "roving ".
The term "yarn spinning" refers to the forming process of the final yarn. The core yarns have a core of elastomeric fibers and a staple fiber sheath. Core-spinning is the process of twisting fibers around an existing yarn (filament or staple yarn) to produce a cis-core structure wherein the yarn already formed is a core. The core-spun yarn can be used in a number of spinning systems, such as ring spinning systems, core wrap spinning methods, patterned spinning systems, core-twin spinning systems, composite electrostatic spinning systems, , A friction-spinning system, or an air-jet spinning system. These are the idiosyncratic systems known to those skilled in the art. One embodiment of the present invention is a spinning of a PTT fiber-to-face sheath using a ring spinning system for making core spinning fibers as described herein. This process is schematically shown in Fig.
Ring spinning produces yarn in a small package called a cop or bobbin. Since the cobbles from the ring frame are not suitable for further processing, the winding process serves to achieve the additional purpose required by the requirements of the subsequent machining step.
The term "winding" refers to the process of obtaining a larger package from several small ring bobbins. This conversion process provides the possibility to exclude undesirable and problematic inadequacies. The process of eliminating these undesirable defects is referred to as yarn cleaning.
Finally, the yarn needs to be conditioned. The term "conditioning" refers to a process which provides an economical device for supplying the necessary moisture in a short period of time in order to achieve a continuous improvement in the quality and processability of the yarn in subsequent processes by reducing the tendency to snarling . Moisture in the atmosphere has a profound effect on the physical properties of textile fibers and yarns. Relative humidity and temperature will determine the amount of moisture in the atmosphere. High relative humidity in different spinning zones is undesirable. On the other hand, however, high humidity improves the physical properties of the yarn. In addition, it aids the yarn in obtaining the standard moisture content value of the fiber.
One aspect of the present invention is a method of making a core yarn, wherein the sheath is a blend or combination of PTT and any other staple fibers other than a face, the process comprising the steps of:
(a) opening;
(b) mixing;
(c) a blowroom process;
(d) Carding
(e) drawing
(f) roving;
(g) core yarn manufacture;
(h) winding; And
(i) Conditioning.
One aspect of the present invention is a method of making denim fabrics using the core yarns and indigo dyed cotton staple fiber yarns of the present invention wherein the process comprises the steps of:
(a) warping of cotton yarn;
(b) Indigo dyeing and sizing of warp yarns;
(c) weaving of indigo dyed cotton fibers with PTT based core yarns;
(d) singeing;
(e) desizing;
(f) heat fixation;
(g) mercerizing (arbitrary);
(h) finishing; And
(i) sanforizing.
A general schematic representation of this process is shown in Fig.
One aspect of the present invention is a method of making a plain bottom-weight fabric using a core yarn of the present invention and any other staple fiber yarn, wherein the process comprises the following steps :
(a) Jung, Kyung;
(b) a head section;
(c) weaving;
(d) calling;
(e) scouring;
(f) bleaching;
(g) Heat fixation
(h) Closure;
(i) shrink-proofing;
(j) in the case of visor fabrics, optionally performing a mercerization step before the finishing step after the heat setting step;
(k) For post-fabrics, the post-finishing step is performed arbitrarily. The dyeing step is carried out before the finishing step.
One aspect of the invention is a method of making a striped fabric using a core yarn of the present invention and any other staple fiber yarn, wherein the process comprises the steps of:
(a) yarn dyeing;
(b) partial cannon;
(c) the head;
(d) weaving;
(e) desizing;
(f) refining;
(g) Closing;
(h) shrink-proofing;
(i) In the case of a side fabric, additional steps of mercerization and decolorization are optionally performed.
Depending on the desired end product, some of the steps in the manufacturing process may be modified. For example, only if there is cotton staple fiber yarn in the fabric, the subsequent bleaching after the mercerizing step is carried out before the finishing step. The dyeing process is only required for colored fabrics. It will be apparent to those skilled in the art that the dyeing step is omitted for the purpose of flat fabrics.
In one aspect of the invention, the polytrimethylene terephthalate based core yarn forms a weft of the fabric.
The term "printed" refers to a fabric printed in the form of a fabric.
The term " canonical "as used herein refers to a process for winding a yarn on an oblique beam.
The term " wick "as used herein generally refers to a process of coating a yarn with starch.
The term "weaving" as used herein refers to a process in which a fabric is produced on a loom during a weaving process in which the warp from the roll is interlaced with a weft laying in the width direction.
The term " call "as used herein refers to the process of removing a callus applied on a slope with the aid of an enzyme or any other suitable chemical.
The term "refining " as used herein refers to a chemical washing process on cotton fabrics for removing natural waxes and non-fibrous impurities and any added soil or contaminants from the fibers. Refining is typically carried out in an iron vessel called a kier. The fabric is boiled in an alkali, which forms a soap with free fatty acids (saponification). Since the keyer is normally closed, the solution of sodium hydroxide is boiled under pressure, so that the oxygen to decompose the cellulose in the fiber can be excluded. Often the call is performed prior to refining and is considered to be a separate process known as fabric preparation, but if appropriate reagents are used, refining will also remove the flakes from the fabric. Preparing and refining is a preliminary preparation for most other finishing processes. At this stage, even the most naturally white cotton fibers are light yellow.
The term "heat setting" is a thermal process that takes place in an environment of mostly dry heat (160 ° C to 180 ° C for 30 to 45 s). The effect of the present process provides dimensional stability to the fabric and very often other desirable properties such as wrinkle resistance or temperature resistance.
The term "mercerization" as used herein refers to the process of treating a fabric with an alkali. This process removes the convolution from the cotton fiber structure and rounds it, which improves the texture of the fabric and makes it more lustrous. In a cotton fabric, mercerization also improves the strength of the fabric.
The term "decolorization" as used herein refers to the process of removing any contamination, staining, or oil stains from the fabric. Decolorization is typically carried out by treating the fabric with sodium hypochlorite or hydrogen peroxide solution.
The term "dyeing" as used herein refers to a process of coloring a fabric after discoloration. For post-fabrics, cotton warp and PTT weft yarns are separately dyed by their respective known dyeing methods. In the case of checkered or striped fabrics, warp or PTT based core wefts can be dyed separately or together, thereby forming a pattern.
As used herein, the term "finish " refers to a process performed on a fabric after weaving to improve the appearance, performance, or" feel "of the finished textile or garment. Different finishing techniques may be used to form the bio-polishing, raising, fulling, calendering, antimicrobial finishing, antistatic finishing, non-slip finishing, Other things. Suitable finishes are used for these finishes.
The term " shrink-proofing "as used herein refers to a treatment process used in particular for cotton fabrics and other textiles made of natural or chemical fibers. It is a method of stretching, shrinking, and fixing both the length and width of a woven fabric before cutting and manufacturing, or otherwise reducing shrinkage that occurs after washing.
The term "yarn dyeing" as used herein refers to a process in which yarns in warp and weft yarns need to be dyed. This is carried out in high-temperature and high-pressure dyeing machines.
The term "partial scene " as used herein refers to a process of winding a yarn on a drum according to a color pattern. Once all the yarn patterns have been wound on the drum, they can be wound into a warper beam and inserted into the fabric according to the streak effect required for the fabric.
The term "denim" as used herein is a rugged cotton twill textile, through which the weft passes under two or more ("double") inclinations. Traditionally, denim has been colored blue with an indigo dye.
As used herein, the term "indigo dyeing" refers to dyeing with indigo dyes using a standard indigo dyeing process such as an indigo rope dyeing process, one-sheet dye slashing, Refers to a process for dyeing fibers.
As used herein, the term "exhaust" refers to the process of incinerating attached loose fibers from a textile product. Consumption is part of the pretreatment process that is performed during textile processing and is typically the first step that is performed after weaving. Consumption is often carried out on fabrics with cotton fabrics, or cotton blends, and can be applied on fabrics with increased wettability (better dyeing characteristics, improved reflectivity, no "frosty" appearance), smoother surfaces Better clarity), improved visibility of the fabric structure, less peeling, and reduced contamination through the removal of fluff and lint. Typically, consumption includes the step of incinerating the protruding fibers by passing / exposing one side or both sides of the fabric over a gas flame. Other consuming methods include infrared consumption and heat dissipation for thermoplastic fibers. The consumption of yarn is referred to as "gassing. &Quot; Cellulosic fibers, such as cotton, are easily consumed because they are burnt to a mild trace of ash where the protruding fibers are easily removed.
The following non-limiting examples are provided by way of illustration and are not to be construed as limiting the scope of the invention.
Example
All chemicals mentioned were purchased unless otherwise specified. All the machinery used is a machine well known in the art.
Example 1
This example illustrates a process for making core yarns using polytrimethylene terephthalate staple fibers and cotton staple fibers.
Poly (trimethylene terephthalate) staple fibers (35 kg, 38 mm fiber length, 1.5 denier) and staple side (from coamed sliver) fibers (65 kg, 31 mm upper quartile average length, 1.5 袖 g / Inch)) was used. The fibers were manually opened and then mixed together. The fibers were mixed by placing two layers of face and one layer of PTT. Such a process is referred to as a lamination mixing process. The entire fiber mass was then taken from the laminate by drawing the material vertically and fed into the blow-room line. The process parameters of the blow-room line selected for PTT / cotton fiber processing were as follows:
Feed roller and beater blade set value = 1.7 mm
Lap line density = 400 g / m
· The waste collection setting is set to '0'.
· Coarse opening beater speed = 400 rpm
· Fine opening beater speed = 450 rpm
After the blow-room line, a fiber fleece was fed to the carding machine using an aero-pneumatic aero feeding system. The process parameters for the carding machine were as follows:
Machine Productivity = 28 kg / hr
Feed Plate and Licker = 32 tau in gauge.
Flat gauge = 12,12,10,10,10 Tau
· Trumpet size = 4.0 mm
· Sliver linear density = 4.5 g / m
· Licker in Speed = 750 rpm
· Cylinder speed = 350 rpm
Flat speed = 12.7 cm / min (5 inches / min)
A sliver with very high mass / length variation along the length came from the carding machine. In order to minimize variations, carding sliver was doubled together and drafted six times at the same time to further orient the fibers along the length in the resulting sliver. Doubling and drafting processes were performed on draw frame machines. Two such drawing processes were performed to reduce the mass / length variation in the sliver to a minimum level and to orient the fibers along the length direction. Two sets of draw frames were machined on the card sliver with the following parameters:
· Lower roller gauge front / rear = 40/44 mm
Trumpet diameter = 3.8 mm
Sliver linear density (both in breaker and finisher) = 4.6 g / m
· Break Draft = 1.7 at the breaker, 1.3 at the finisher draw frame
· Web tension draft = 1
Krill tension draft = 1.02 to 1.03
· Transfer speed = 200 to 250 mpm in the breaker draw frame, 350 to 400 mpm in the finisher draw frame
Doubling = 6 times for both braking and finisher frames
Using the process parameters listed below, the sliver from the finisher frame was converted to roving on the speed frame:
· Spacer size = 5.5 mm
· Spindle speed = 750 rpm
Twist Multiplier = 1.2
· Roller gauge = 48/64 mm
Saddle gauge = 54 / 60.5 mm
The roving produced on the speed frame is further converted to yarn by further drafting along a final spinning machine called a ring frame. The yarn count yarn spun was 9.6 s Ne. The denier of the core spandex filament was 70 D. The spandex was provided with a draft of 2.1 before it was put into the yarn. The percentage of spandex in the final yarn was 6.3%. The process parameters of the ring frame were as follows:
· Roller gauge = 42.5 / 65 mm
· Saddle gauge = 51/66 mm
· Cot Hardness (front / rear) = 68/83
· Brake Draft = 1.2
· Twist coefficient = 4.3
The final package (cob) obtained from the machine was weighed to approximately 800 gm (net weight).
Each of these 80 g small cobbles was bonded and any yarn defects were removed and finally wound on a large final package called a cone on a winding machine. The process parameters maintained on the winding machine are as follows:
Speed = 1000 mpm
Yarn tension = breaking load of 5 to 6%
· Package hardness setting value: Minimum
Cone weight = 2.0 kg
The yarn was conditioned in an autoclave at 70 DEG C for 50 min. Yarn cones were used directly as weft yarns in fabric fabrication processes where stretching in the fabric was required in the width direction. However, these yarns can also be used in the longitudinal direction to obtain an oblique stretch or two-stretch fabric.
Example 2
This example illustrates a process for producing a denim fabric by using the core yarn obtained from Example 1 as a weft.
Fabrics were prepared using an air jet weaving machine. The slope was 100% indigo dyed cotton staple fiber. The fiber was the core yarn obtained from Example 1. The process parameters of the machine were as follows:
· Loom speed = 750 rpm
· Fabric width = 172.7 cm (68 inches)
· Twill twill = 3/1 twill twill
· 27.5 ends / centimeters (end / inch = 70)
· 17.3 Pick / centimeter (pick / inch = 44)
· Slope count = (7.2s + 6.4s) Ne (1 + 1), 100% cotton ring yarn
Weft count = 9.6 s Ne (70 D spandex (6.27%) with core yarn)
The resulting fabric was consumed by passing it on a set of burners at 80 mpm on a fabric-wasting machine. The protruding fibers on the surface were removed by burning. The fabric was then digested by padding with enzyme for 12-18 hr. The fabric is then washed with water. The fabric was mercerized by treating the fabric at 40 mpm at 65 [deg.] C with 18.5% NaOH solution. The fabric was then dried at 105 DEG C by passing the fabric through a set of calender rollers. The fabric was then passed through a shrink-proofing machine to pass skew, length, and width shrinkage by passing the fabric through the rubber roller in a steam chamber (Monforte) at 50 mpm. This made the final garment dimensionally stable with an acceptable shrinkage percentage and an improved tactile feel of the fabric. The resulting fabric was already finished fabric and could be converted into garments.
Table 1 below shows the test results for the desired properties of the denim fabric produced by the above examples.
[Table 1]

Claims (10)

A core spun yarn comprising a core comprising a stretchable filament surrounded by a sheath comprising polytrimethylene terephthalate based staple fibers in combination with a second staple fiber. The core yarn according to claim 1, wherein the extensible filaments are spandex filaments. The core yarn of claim 1, wherein the second fiber is selected from the group consisting of cotton, viscose, polyester, nylon, modal, tencel, wool, and combinations thereof. The core yarn according to claim 1, wherein the polytrimethylene terephthalate staple fiber content in the sheath is in the range of 10% to 60%. The core yarn of claim 2 wherein the spandex filament content is in the range of 2 to 10%. The core yarn according to claim 1, wherein the second staple fiber is cotton staple fiber. A core yarn comprising a core comprising an extensible filament surrounded by a sheath comprising polytrimethylene terephthalate based staple fibers in combination with a second staple fiber. The fabric according to claim 7, having a weft yarn and a warp yarn, wherein the core yarn is a weft and the warp yarn is selected from the group consisting of nylon, polyester, wool, viscose, and combinations thereof. The fabric of claim 7, having a stretch recovery in the range of 75 to 95% and a growth of < 2.3%. 8. The fabric of claim 7, wherein the fabric is used in an application selected from the group consisting of clothing, sheeting material, furnishing, and upholstery.

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