KR102057479B1 - Stretchable and dimensionally stable woven fabric made from polytrimethylene terephthalate based core spun yarns - Google Patents

Abstract

A core spun yarn wherein the core is an extensible filament and surrounded by a sheath of polytrimethylene terephthalate-based staple fibers in combination with a second staple fiber. Fabrics are made using the core spun yarn. Fabrics made from core spun yarn are highly stretchable and have high dimensional stability, low growth, and high recovery.

Description

Stretchable and Dimensionally Stable Woven Fabric Made of Polytrimethylene Terephthalate Core Spun Yarn

This application claims the benefit of Indian Provisional Patent Application 3632 / DEL / 2011, filed December 13, 2011, which is incorporated herein by reference.

FIELD OF THE INVENTION The present invention relates to polytrimethylene terephthalate (PTT) based core spun yarns wherein the core of the yarn comprises extensible filaments and the sheath comprises polytrimethylene terephthalate based staple fibers.

The invention further relates to highly stretchable fabrics exhibiting high recovery and low growth, wherein the PTT-based core spun yarn is in the weft direction.

The apparel industry has a constant need for a wider variety of better and newer fabrics to meet the evolving evolving needs of discerning consumers. One of the needs of the apparel industry is the need for stretchable fabrics with a comfortable fit.

Core spun yarns (CSY) are widely used in the production of stretch fabrics used in the manufacture of denim, bottoms, and shirts. CSYs known in the art typically have cotton, polyethylene terephthalate (PET), viscose, nylon, or blends thereof as their sheath components with Lycra or spandex filaments forming the core. CSY garments have an elongation level ranging from 7 to 35% depending on the percentage of spandex in the core. Fabrics made at a stretch level of 8 to 15% are called comfort stretch fabrics. Fabrics having a stretch level of 16 to 35% are called super stretch fabrics. Fabrics with a stretch level of 35% have a high spandex percentage (about 9-10%). This leads to undesirable high% growth or low recovery potential. Fabrics with a stretch level of almost 15% have a growth rate of almost 5% and a recovery level of only 70%. This leads to baggy formation and dimensional instability of the final garment after some use.

WO 2008130563 is an elastic composite used as warp and weft for woven fabrics comprising a filamentous core comprising elastic performance filament (s) and inelastic control filament (s), and a fibrous sheath comprising spun staple fibers. Start the yarn.

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

Described herein is a core spun yarn comprising a core comprising extensible filaments surrounded by a sheath comprising polytrimethylene terephthalate-based staple fibers in combination with a second staple fiber.

Also described herein is a fabric comprising the core spun yarn.

<Figure 1>
1 is a schematic representation of core spun yarn production.
<FIG. 2>
2 is a schematic representation of fabric (denim) fabrication using core spun yarn.
Detailed description of the invention
Described herein is a fabric made from core spun yarn (CSY). CSYs comprising polytrimethylene terephthalate-based staple fibers are also described. CSY is a yarn composed of inner core yarn surrounded by staple fibers. The surrounding staple fibers thus form a sheath of CSY. The core spun yarn combines the strength and / or elongation of the core yarn with the characteristics of the staple fiber sheath forming the surface.
The fabric is a woven fabric that is stretchable and dimensionally stable and comfortable to wear, and has high stretching properties combined with good stretch recovery and less growth.
The fabric also addresses the realistic aspects of growth in highly stretchable heavy fabrics such as denim, bottom fabrics, and suit fabrics in addition to the above traits.
As used herein, the terms "polytrimethylene terephthalate" or "PTT" are used interchangeably. Polytrimethylene terephthalate is bio-origin, bio-based, or petroleum based.
As used herein, the term “staple fiber” refers to a fiber of standardized length, unlike continuous fibers known as filaments. Staple fibers are cut to a specific length from continuous filament fibers. Typically the staple fibers are cut into lengths ranging from 1 to 1/2 inch (2.5 to 1.3 cm) to 20.3 cm (8 inch) long.
The core spun yarn has stretchable filaments and has an inner core surrounded by a sheath of polytrimethylene terephthalate staple fibers in combination with the second staple fibers.
The extensible filament may be spandex filament. 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-based staple fiber” refers to 100% polytrimethylene terephthalate (PTT) staple fiber, or nylon, styrene, polyethylene terephthalate (PET) or blend staple fiber thereof. PTT in combination with other polymers selected from.
In one embodiment of the invention, the PTT-based staple fibers are combined with a second staple fiber selected from cotton, polyester, viscose, nylon, modal, tencel, wool, or a combination 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 weft of the sheath contributes to the stretch recovery properties in CSY.
"Woven fabric" is used to define a fabric made by interlacing two sets of yarns called warp (warp) and weft (weft). The warp runs longitudinally in the fabric and the weft runs in the width direction in the fabric. Fabrics are woven by techniques well known in the art such as plain weave, satin weave, and twill weave.
The core of CSY can be a stretchable fiber or filament selected from the group of spandex and lycra®. In one embodiment of the invention, the percentage of stretchable fibers in the yarn ranged from 2% to 10%, or from 5 to 8%, or from 5 to 6%.
In one embodiment of the invention, the sheath comprises a weft yarn which is CSY as described herein, and the slope is selected from cotton, nylon, polyester (e.g. PET, PTT), wool, viscose, and combinations thereof. Staple fiber yarn.
As used herein, the term "stretchability" refers to the property of a fabric that extends to a certain length percentage when applying a fixed amount of load. Fabrics with good drawing properties are defined by the ability of the fabric to extend to its maximum and recover with leaving a minimum amount of growth 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 "comfortable-stretch" fabrics. Stretch properties and growth are measured using standard ASTM international procedures (see Table 1).
One aspect of the invention is a fabric consisting of a core spun yarn, wherein the inner core of the core spun yarn comprises stretchable filaments and is surrounded by a sheath of polytrimethylene terephthalate-based staple fibers combined with a second fiber.
The fabrics of the present invention have a high "dimension stability", which means that they have maximum recovery and minimum growth remaining in the fabric after stretching is released.
As used herein, the term "stretch recovery" refers to the ability of a fabric to extend to its maximum and recover, leaving a minimum amount of growth on the fabric after removal of the applied load. Acceptable stretch recovery has greater than 70% stretch recovery. More than 70% recoverability and less than 2.5% growth in the fabric makes it a dimensionally stable fabric. Stretch recovery and growth properties 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 Conshohoken, Pennsylvania). ASTM International publishes the Annual Book of ASTM Standards annually.
In one embodiment, the fabric of the present invention has stretch recovery in the range of 75-95%, or 80-95%.
In another embodiment, the fabric of the invention has less than 2.5%, or less than 2.3% growth.
In addition to high stretch (greater than 15%), high recovery (greater than 70%), and low growth (less than 3%), the fabrics of the present invention have a good fit that is comfortable to wear, provide UV protection, and provide a core of the fabric. PTT sheaths in the yarn provide acid and alkali resistance during washing.
The fabrics of the present invention are selected from plain fabrics, denim fabrics, bottom fabrics, shirt fabrics, latex fabrics, printed fabrics, checked fabrics, and striped fabrics.
The fabrics described herein can be used, for example, in the manufacture of garments, sheeting materials such as bed sheets, furnishings, or upholstery.
One aspect of the invention is a method of making a core spun yarn wherein the sheath is a bicomponent fiber comprising PTT and cotton staple fibers, the process comprising the following steps:
(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 cotton staple fibers;
(f) opening the PTT based fibers and cotton staple fibers obtained from the combing step;
(g) mixing two fibers;
(h) blow-room processes;
(i) carding;
(j) drawing;
(k) roving;
(l) yarn production;
(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 PTT based fibers and the process steps (f) to (n) described above are applied.
The term "blow-room process" refers to a process of processing fibers in an "blow-room line" after opening and mixing. The blow-room line consists of a number of machines that are used in series to open and clean cotton fibers. About 40% to 70% of the trash is removed in the blow-room section. The object of the blow-room (cotton and PTT staple fibers) is cleaned after opening, where the fibers are opened from larger tuft sizes (hundreds of grams) to smaller tuft sizes (mg units). Subsequently, cleaning is followed to remove contaminants, dust, broken seeds, broken leaves, and other unwanted materials from the fibers. In order to produce good quality yarns and reduce manufacturing, both processes involve mixing and blending. This is followed by a wrap or fleece formation, where the opened and cleaned fibers are converted to a sheet form (called a wrap) with a clear width and length, or in modern systems these sheets are fed directly to the carding machine. To form a fleece.
The term "carding" refers to the process of loosening the fiber bundles into individual fibers and arranging them in parallel after individualizing the fibers. It also further removes waste and other foreign matter and fibers not acceptable for manufacture. The carding machine consists of a moving conveyor belt with a fine wire brush and a revolving cylinder to perform operations on cotton, wool, waste silk, and synthetic staple fibers. The material transferred from the carding machine is called sliver or card sliver.
The carding process opens up the collected mass of fibers so that the fibers are individual fibers. However, the fibers in the card slivers are not completely aligned or oriented with the fiber axis. Some fibers are placed randomly in 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 slivers pass between sets of rollers that operate at different speeds, and each subsequent pair rotates faster than the previous pair so 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 the process of combining multiple slivers. By this process, the thin and thick place existing in the sliver is even. Within the sliver wrap machine, 16 to 20 card slivers are krilled and passed through a pair of drafting rollers through a feed table for drafting operations. The drafted sliver is then sent to two pairs of calender rollers that compress the sliver material. This drafted and compressed sliver material, called a wrap, is wound onto the spool. This process is known as "wrap formation".
"Coaming" is an additional fiber alignment operation performed on very fine yarns with the intention of finer fabrics. (Low cost, coarser fabrics are made from slivers that are processed without such additional purification.) Combing a slender comb to the sliver from the coaming separates shorter fibers, called foils, and lengthens the longer fibers. Align to higher levels of parallelism. The resulting strand is called a comb sliver. The comb sliver, using its long fibers, provides a softer and more even yarn.
The term “drawing” refers to the process (after carding) of combining several slivers into one strand that is drawn longer and thinner. The sliver coming out of the carding machine has a high mass / length variation along its length. To minimize this, a doubling and drafting process is performed 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 longitudinal direction. The first drawing process is called breaker drawing and the second drawing process is called finisher drawing. The drawing frame has several pairs of rollers through which the slivers pass. Each subsequent pair of rollers 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 process through several steps.
The sliver delivered from the frame to the finisher has a minimum mass / length variation and the fibers oriented towards the strand axis contribute to the tensile properties. However, the linear density of the sliver is approximately 140 times the final yarn required. There is a need to further reduce this to the required yarn linear density. This can be done in an additional process of drafting, in a two stage drafting process, a speed frame machine and a ring frame machine. Drafting in a single step leads to the introduction of high mass / length variations, so this two-step drafting process is recommended. However, as the number of fibers in the sliver continues to decrease, the fibers need to be secured in a continuous fashion to each other and have strength to allow the fibers to be processed on the next machine. To give 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 called roving preparation. By this drafting operation the sliver becomes finer and the resulting product is called "roving".
The term "yarn spinning" refers to the process of forming the final yarn. Core spun yarns have a core of elastomeric fibers and a sheath of staple fibers. Core-spun is a process of twisting fibers around existing yarns (filament or staple yarns) to produce a sheath-core structure, where the yarns already formed are cores. Core-spun yarns can be 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, rotor spinning systems , Friction spinning systems, or air jet spinning systems. These are conventional systems well known to those skilled in the art. One embodiment of the present invention is the spinning of PTT-based fiber-cotton sheaths using a ring spinning system for producing core spun fibers as described herein. This process is schematically shown in FIG.
Ring spinning produces yarn in small packages called Cops or bobbins. Since the cobs from the ring frame are not suitable for further processing, the winding process serves to achieve the additional purpose required by the requirements of subsequent processing steps.
The term "winding" refers to the process of obtaining a larger package from some small ring bobbins. This conversion process offers the possibility of eliminating unwanted and problematic inadequate defects. The process of eliminating these inadequate defects is called yarn 'cleaning'.
Finally the yarn needs to be conditioned. The term “conditioning” refers to a process that provides an economical device for supplying the necessary moisture in a short time to achieve a continuous improvement of yarn quality and processability in subsequent processes by reducing the tendency of 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 assists the yarn to obtain a standard moisture content value of the fiber.
One aspect of the invention is a method of making a core spun yarn in which the sheath is a blend or combination of any other staple fibers other than PTT and cotton, the process comprising the following steps:
(a) opening;
(b) mixing;
(c) blow room process;
(d) carding
(e) drawing
(f) roving;
(g) core yarn preparation;
(h) winding; And
(i) conditioning.
One aspect of the invention is a method of making a denim fabric using the core spun yarn of the invention and an indigo dyed cotton staple fiber yarn, wherein the process includes the following steps:
(a) warping of cotton yarn;
(b) warp indigo staining and sizing;
(c) weaving of indigo dyed cotton fibers with PTT-based core yarns;
(d) singing;
(e) desizing;
(f) heat fixation;
(g) mercerizing (optional);
(h) finishing; And
(i) sanforizing.
A general schematic representation of this process is shown in FIG. 2.
One aspect of the invention is a method of making a plain bottom-weight fabric using the core spun yarn of the invention and any other staple fiber yarn, wherein the process comprises the following steps: :
(a) canon;
(b) housewife;
(c) weaving;
(d) callout;
(e) scouring;
(f) bleaching;
(g) heat fixation
(h) deadlines;
(i) preshrunk;
(j) for cotton-based fabrics, optionally performing a mercerization step after the heat fix step before the finishing step;
(k) In the case of late dyeing fabrics, the dyeing step is optionally carried out. The dyeing step is done before the finishing step.
One aspect of the present invention is a method of making a striped fabric using the core spun yarn of the present invention and any other staple fiber yarn, wherein the process comprises the following steps:
(a) yarn dyeing;
(b) partial canon;
(c) housewife;
(d) weave;
(e) desizing;
(f) refining;
(g) finishing;
(h) preshrunk;
(i) For cotton based fabrics, additional steps of mercerization and decolorization are optionally carried out.
Depending on the desired end product, some of the steps in the manufacturing process may be modified. For example, if only cotton staple fiber yarns are present in the fabric, subsequent bleaching after the mercerization step is carried out before the finishing step. The dyeing process is only required for colored fabrics. It is apparent to those skilled in the art that the dyeing step is omitted for plain fabric purposes.
In one aspect of the invention, the polytrimethylene terephthalate-based core spun yarn forms the weft of the fabric.
The term "printed" refers to a fabric printed in the form of a fabric.
As used herein, the term "canon" refers to the process of winding a yarn on a warp beam.
As used herein, the term "head" refers to a process of coating a thread with starch, typically.
The term "weaving" as used herein refers to a process in which a fabric is made on a loom during the weaving process, in which the warp from the roll is interlaced with the weft yarn lying in the width direction.
As used herein, the term “calling” refers to a process of removing a call applied on a slope with the aid of an enzyme or any other suitable chemical.
As used herein, the term "refining" refers to a chemical laundry process on cotton fabrics to remove natural wax and non-fibrous impurities and any added dirt or contaminants from the fiber. Refining is usually carried out in an iron vessel called a kier. The fabric is boiled in alkali, which forms a soap with free fatty acids (soap). Since the keyer is normally sealed, it is possible to exclude oxygen that will break down the cellulose in the fiber by boiling the solution of sodium hydroxide under pressure. Although firing is often considered to be a separate process performed prior to refining and known as fabric preparation, refining will also remove excavations from the fabric when appropriate reagents are used. Preparation and refining are preliminary preparations for most other finishing processes. At this stage, even the naturally whitest cotton fibers are pale yellow.
The term “heat fixation” is a thermal process that occurs mostly in dry heat (160 ° C. to 180 ° C. for 30 to 45 s) environment. The effect of the present process provides the fabric with other desirable properties such as dimensional stability, and very often wrinkle resistance or temperature resistance.
As used herein, the term "mercerization" refers to the process of treating a fabric with an alkali. The process removes the convolution from the cotton fiber structure and makes it round, which improves the feel of the fabric and makes it more glossy. In cotton-based fabrics, mercerization also improves the strength of the fabric.
As used herein, the term “bleaching” refers to the process of removing any stains, colored stains, or oil stains from a fabric. Decolorization is commonly carried out by treating the fabric with sodium hypochlorite or hydrogen peroxide solution.
As used herein, the term "dyed" refers to the process of dyeing the fabric after color bleaching. In the case of latex fabrics, the cotton warp and the PTT-based weft are dyed separately by their known dyeing methods. In the case of checkered or striped fabrics, warp or PTT based core wefts can be dyed separately or together, thus 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” (feel) of the finished textile or garment. Different finishing techniques are bio-polishing, raising, fulling, calendering, antimicrobial finishing, antistatic finishing, non-slip finishing, and known in the art. Other things. Suitable finishes are used for these finishes.
As used herein, the term "shrink" 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 sticking woven fabrics in both length and width prior to cutting and manufacturing to reduce shrinkage that would otherwise occur after washing.
As used herein, the term “yarn dyeing” refers to a process that needs to dye yarns in warp and weft yarns. This is done in high temperature and high pressure dyeing machines.
The term "partial canon" as used herein refers to a process of winding yarn onto 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 stripe effect required for the fabric.
As used herein, the term "denim" is a rugged cotton twill textile in which the weft passes down two or more ("double") slopes. Traditionally, denim was colored blue using indigo dyes.
As used herein, the term “indigo dyeing” is used to warp cotton with indigo dyes using standard indigo dyeing processes such as indigo rope dyeing processes, indigo one-sheet dye slashing, indigo double sheet dyeing, and the like. Refers to the process of dyeing fibers.
As used herein, the term "consumption" refers to the process of incinerating attached loose fibers from a textile product. Consumption is part of the pretreatment process performed during textile processing and is typically the first step performed after weaving. Consumption is often carried out on cotton fabrics, or fabrics with cotton blends, with increased wettability (better dyeing characteristics, improved reflectivity, no "frosty" appearance), smoother surfaces (for printing Better clarity), improved visibility of the fabric structure, less peeling, and removal of down and lint, resulting in reduced contamination. Consumption typically involves incineration of the protruding fibers by passing / exposing one or both sides of the fabric over a gas flame. Other burnout methods include infrared burnout and heat burnout for thermoplastic fibers. The consumption of yarn is called "gassing". Cellulose-based fibers, such as cotton, are easily consumed because they are burned in light trace amounts of ash that the protruding fibers are easily removed.
The following non-limiting examples are for illustrative purposes and should not be construed as limiting the scope of the invention.
Example
All chemicals mentioned were purchased unless otherwise noted. All the machines used are machines well known in the art.
Example 1
This example illustrates the manufacturing process of a core spun yarn using polytrimethylene terephthalate staple fibers and cotton staple fibers.
Polytrimethylene terephthalate staple fiber (35 kg, 38 mm fiber length, 1.5 denier) and staple cotton (from combed sliver) fiber (65 kg, 31 mm upper quartile average length, 1.5 μg / cm (4.0 μg / cm) Inches)). The fibers were opened manually and then mixed together. The fibers were mixed by placing two layers of cotton and one layer of PTT. This process is called a lamination mixing process. The whole fiber mass was then taken out of the stack by feeding 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
Wrap linear density = 400 g / m
Waste collection set point is set to '0'
Rough opening beater speed = 400 rpm
Fine opening beater speed = 450 rpm
After the blow-room line, the 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 Production = 28 kg / hr
Feed Plate and Licker in the Gauge = 32 Thou
Flat Gauge = 12,12,10,10,10 Tau
Trumpet Size = 4.0 mm
Sliber linear density = 4.5 g / m
Licker in Speed = 750 rpm
Cylinder speed = 350 rpm
Flat rate = 12.7 cm / min (5 inches / min)
Slivers with very high mass / length variations along the length came out of the carding machine. The cards were further oriented along the length direction in the resulting slivers by doubling the carding slivers together and drafting six times simultaneously to minimize variations. The doubling and drafting process was performed on the draw frame machine. 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 longitudinal direction. The card slivers were processed on two sets of draw frames with the parameters listed below:
Lower roller gauge front / rear = 40/44 mm
Trumpet diameter = 3.8 mm
Sliber linear density (both breaker and finisher) = 4.6 g / m
Break Draft = 1.7 in Breaker, 1.3 in Finisher Drawer Frame
Web tension draft = 1
Krill Tension Draft = 1.02 to 1.03
Delivery speed = 200 to 250 mpm in breaker draw frame, 350 to 400 mpm in finisher draw frame
Doubling = 6 times for both breaking and finisher frames
The sliver from the frame was converted to roving on the speed frame with the finisher using the process parameters listed below:
Spacer size = 5.5 mm
Spindle Speed = 750 rpm
Twist Multiplier = 1.2
Roller Gauge = 48/64 mm
Saddle gauge = 54 / 60.5 mm
Rovings made on the speed frame are converted into yarn by further drafting along a final spinning machine called a ring frame. The yarn count spun was 9.6 s Ne. The denier of the core spandex filament was 70 D. Spandex was provided with a draft of 2.1 before putting it into yarn. The percent 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
Coat hardness (front / rear) = 68/83
Brake Draft = 1.2
Twist Coefficient = 4.3
The final package (cop) obtained from the machine was weighed approximately 800 gm (net weight).
Each 80 g of these small cobbs were combined 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 = 5 to 6% yarn breaking load
Package Hardness Setting: Min
Cone weight = 2.0 kg
The yarn was conditioned at 70 ° C. for 50 min in the autoclave. Yarn cones were directly used as weft yarns in the fabrication process, which required stretching in the fabric in the width direction. However, these yarns can also be used in the longitudinal direction to obtain obliquely stretched or two-stretched fabrics.
Example 2
This example illustrates the process of producing a denim fabric using the core spun yarn obtained in Example 1 as the weft yarn.
Fabrics were made using an airjet weaving machine. The warp was 100% indigo dyed cotton staple fiber. The weft was a core spun yarn obtained from Example 1. The process parameters of the machine were as follows:
Loom speed = 750 rpm
Fabric width = 172.7 cm (68 in)
Twill = 3/1 Right Twill
27.5 ends / centimeter (ends / inch = 70)
17.3 Pick / Centimeter (Pick / Inch = 44)
Warp count = (7.2s + 6.4s) Ne (1 + 1), 100% cotton ring yarn
Weft count = 9.6 s Ne (with 70 D spandex (6.27%) core spun yarn)
The resulting fabric was consumed by passing over a set of burners at 80 mpm on a fabric consumption machine. The fibers protruding on the surface were removed by burning. The fabric was then launched by padding with enzyme for 12-18 hr. The fabric is then washed with water. The fabrics were mercerized by treating the fabrics at 40 ° C. at 65 ° C. with 18.5% NaOH solution. The fabric was then dried at 105 ° C. by passing the fabric through a set of calender rollers. The fabric was then passed at 50 mpm over a rubber roller in a steam chamber (Monforte), through which the fabric was passed through a preshrunk machine to adjust skew, length, and width shrinkage. This made the final garment dimensionally stable with an acceptable percentage of shrinkage and an improved hand feel of the fabric. The resulting fabric was already finished and can be converted into garments.
Table 1 below shows the test results for the desired properties of the denim fabrics produced by the above examples.
TABLE 1

Claims (10)

A core comprising a stretchable spandex filament surrounded by a sheath comprising polytrimethylene terephthalate-based staple fibers in combination with a second staple fiber, wherein the second staple fiber is cotton, Core spun selected from the group consisting of viscose, polyester, nylon, modal, tencel, wool, and combinations thereof, wherein the polytrimethylene terephthalate-based staple fiber content in the sheath ranges from 10% to 60% by weight. yarn). delete delete delete The core spun yarn of claim 1, wherein the spandex filament content of the entire core spun yarn ranges from 2 to 10 wt%. The core spun yarn of claim 1, wherein the second staple fiber is cotton staple fiber. A core comprising an extensible spandex filament surrounded by a sheath comprising polytrimethylene terephthalate-based staple fibers in combination with a second staple fiber, wherein the second staple fiber is cotton, viscose, polyester, nylon, modal, A fabric comprising a core spun yarn selected from the group consisting of tencels, wools, and combinations thereof, wherein the polytrimethylene terephthalate-based staple fiber content in the sheath ranges from 10% to 60% by weight. The fabric of claim 7 having a weft yarn and warp yarn, wherein the core spun yarn is a weft yarn and is selected from the group consisting of warp cotton, nylon, polyester, wool, viscose, and combinations thereof. The fabric of claim 7 having a stretch recovery in the range of 75-95% and a growth of <2.3%. The fabric of claim 7 used in an application selected from the group consisting of garments, sheeting materials, furnishings, and upholstery.

Images