HK1123583B - Method to make circular knit elastic fabric comprising spandex and hard yarns - Google Patents
Method to make circular knit elastic fabric comprising spandex and hard yarns Download PDFInfo
- Publication number
- HK1123583B HK1123583B HK09100056.2A HK09100056A HK1123583B HK 1123583 B HK1123583 B HK 1123583B HK 09100056 A HK09100056 A HK 09100056A HK 1123583 B HK1123583 B HK 1123583B
- Authority
- HK
- Hong Kong
- Prior art keywords
- fabric
- elastic
- yarn
- spandex
- jersey
- Prior art date
Links
Description
Background
1. Field of the invention
The present invention relates to circular knitting of yarns into a fabric, and in particular to a circular knit, elastic fabric comprising at least one of spun and/or filament hard yarns (hard yarn) and bare elastomeric yarns of single jersey, jersey back (French terry), and fleece. In particular, the present invention relates to fabrics that are circular knit in a manner wherein the stretch of the uncoated elastic yarns is controlled and a wet-set step is employed to provide a finished fabric having predetermined in-use characteristics without the need for an additional dry heat-set step.
2. Brief description of the technology
Single knit jersey fabrics have been widely used to make underwear and thin garments such as T-shirts. Knitted fabrics can be deformed or stretched more easily than woven structures, forming the individual knitted loops (consisting of interconnected loops) of the knitted fabric by pressing or stretching. This ability to stretch by stitch rearrangement adds to the comfort of wear of garments made from knitted fabrics. Even if the knitted fabric is composed of 100% tightly twisted yarn (such as cotton, polyester, nylon, acrylic, or wool), the knitted loops return to their original size to some extent after the forcible force is removed. However, the return by rearrangement of the knitting loops is generally incomplete, since the tightly twisted yarn (which is not elastic) does not provide sufficient return force to completely rearrange the knitting loops. Thus, the single knit fabric may permanently deform or "bow" in certain areas of the garment where more stretch is applied, such as at the elbows of the shirt sleeves.
To improve the recovery properties of circular single jersey fabrics, it is now common to co-knit a small amount of elastic fiber, such as spandex fiber, with an accompanying tight-twist yarn.
Traditionally, if the spandex is "set" without heat setting after the fabric has been knitted and released from the constraints of a circular knitting machine, the elastic spandex fibers in the fabric will contract to compress the weave, thereby reducing the fabric size compared to those sizes in which spandex fibers are not present.
Heat setting is not used for all weft-knitted elastic fabrics. In some cases, heavy knits are required, such as double jersey/rib and plain knits. In these cases, some coil compression by the spandex is acceptable. In other cases, uncoated spandex fibers are coated with natural or synthetic fibers in a core-spun or bobbin-coating process, so that spandex recovery and resulting coil compression are limited by the coating. In still other cases, only the non-covered or covered spandex is plated onto every second or third knitted loop course, thus limiting the total restoring force of the compressed knitted loops. In seamless knitting (a process in which a circular knit fabric is formed for immediate use while knitting on a special machine), the fabric is not subjected to heat setting because it is intended to produce a tight elastic fabric. However, in the case of circular knit elastic fabrics of at least one of single jersey, back loop jersey, and fleece, which are prepared for cutting and sewing, in which uncoated spandex fibers are plated into each course, heat setting is almost always required.
Heat setting has several drawbacks. Heat-setting is an additional cost to finish a knitted elastic fabric comprising spandex fibers, as opposed to a non-elastic fabric (a stiff fabric). In addition, high spandex fiber heat-set temperatures can negatively impact the yellowing of sensitive companion twist yarns, such as cotton, requiring more aggressive post-finishing processes such as bleaching. Aggressive bleaching can negatively impact fabric tactile properties, such as the hand of the fabric, and often requires the manufacturer to add fabric softeners to eliminate the effect of bleaching. In addition, some fibers cannot withstand high temperature heat treatments. Heat sensitive tightly twisted yarns, such as those of polyacrylonitrile, wool and acetate fibers, cannot be used in the high temperature spandex heat-set step, since high heat-set temperatures would negatively affect such heat sensitive yarns. Finally, other fibers are sensitive to heat due to the low melting point of the fibers. For example, polypropylene has a softening point of 155 ℃, which makes it unsuitable for textile processing requiring heat setting.
The drawbacks of heat-setting have long been recognized, and thus, spandex compositions that are heat-set at lower temperatures have been identified (U.S. Pat. Nos. 5,948,875 and 6,472,494, both of which are expressly incorporated herein by reference in their entirety). For example, spandex fibers as defined in U.S. patent 6,472,494 have a heat-set efficiency greater than or equal to 85% at temperatures approaching 175 c to 190 c. A heat-set efficiency of 85% is considered as the minimum for effective heat-setting. It is determined by laboratory testing comparing the length of the stretched spandex fiber before and after heat setting to the length of the spandex fiber before stretching. While such low heat set spandex compositions provide improvements, there is still a need for heat setting without a significant reduction in the costs associated therewith.
The traditional practice of preparing circular knit fabrics and heat setting them has other drawbacks. The knitted fabric coming out of the circular knitting machine is a continuous cylinder. When the knitting forms a sleeve, it is either wound under tension onto a mandrel or collected as a flat cylinder under the knitting machine by folding or loose folding. In either case, the fabric forms two permanent folds where the fabric tube is folded or flattened. Although the fabric is opened by cutting the fabric cylinder along one crease, the subsequent use and cutting of the fabric must generally avoid the crease that still exists. This reduces the fabric yield (or the amount of knitted fabric that can be further processed into a garment).
In view of the above-described deficiencies, there is a need for a method of making a circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece that plats an uncoated elastic material with a spun yarn and/or a filament tight twist yarn that avoids the costs and deficiencies associated with prior art dry heat setting methods. In addition, the present invention allows the production (stabilization, dyeing and finishing) of circular knit elastic fabrics of at least one of single jersey, back loop jersey and fleece as cylinders, with material usage rates exceeding the prior art.
Summary of The Invention
The present invention provides a circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece comprising an unclad elastic plated with spun yarns and/or filaments, wherein the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece is produced with commercially acceptable properties without the need for dry heat setting of the elastic fibers in the fabric because: (1) the stretching of the elastic fiber can be limited in the knitting process; (2) certain desired single jersey parameters can be maintained; and (3) said circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile can be contacted with the continuous phase aqueous solution under conditions of temperature and pressure for a time sufficient to substantially set said bare elastomeric material.
The first aspect of the invention comprises a method of making a circular knit, single jersey elastic fabric in which an uncoated elastic material, such as an uncoated spandex yarn (15 to 156dtex, e.g., 17 to 78 dtex), can be plated with at least one spun and/or filament yarn tight-twisted yarn or blend thereof (yarn count (Nm) of 10 to 165, e.g., 44 to 68). The invention also includes a method of making a circular knit elastic fabric of at least one of a back loop flat knit fabric and a pile wherein an uncoated elastic material, such as an uncoated spandex yarn (15-156 dtex, e.g., 22-78 dtex), can be plated with at least two spun and/or filament tight yarns or blends thereof (yarn count (Nm) of 10-165, e.g., 34-68). In the circular knitted elastic fabric of at least one of the back loop plain knit fabric and the pile, the at least two types of tightly twisted yarns may be different. In the circular knitted elastic fabric of at least one of the back loop plain knit fabric and the pile, the at least two tightly twisted yarns may be the same.
The elastic material and the hard twist yarn can be plated to produce knitted fabrics such as circular, open width, warp knit, double jersey, rib, pile, and interlock fabrics. The circular knitting elastic fabric of at least one of single jersey, back loop plain knit and pile prepared by the knitting method has the cover factor of 1.05-1.9. During knitting, the stretch of the elastic material feed may be controlled such that the elastic material may stretch no more than about 7 x, typically no more than 5 x, such as no more than 3 x, of its original length when knitted into a circular knit elastic fabric that forms at least one of a single jersey, a back loop jersey, and a pile.
The method further includes a stabilizing step comprising heat moisture setting the circular knit, elastic of at least one of single jersey, back loop jersey, and pile and at a temperature and for a time sufficient to cause the elastic material in the circular knit, elastic of at least one of single jersey, back loop jersey, and pile to change and become substantially "set". For example, the stabilizing step can include wet-setting the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile in a spray dryer at a temperature of about 105 ℃ to about 145 ℃ for a dwell time of about 5 minutes to about 90 minutes. The stabilization step re-refines the spandex to reduce fabric loading and unloading power and fabric basis weight (basis weight). Due to the stabilizing step, the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile may not have to be subjected to a dry heat setting step, such as heating the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile to above about 160 ℃ under tension in air having a relative humidity of less than about 50% on a tenter frame.
The circular knit, elastic of at least one of single jersey, back loop, and pile can then be dyed, finished, and/or dried at a temperature below the spandex heat-set temperature without dry heat-setting the spandex in the circular knit, elastic of at least one of single jersey, back loop, and pile or the circular knit, elastic of at least one of single jersey, back loop, and pile. Finishing may include one or more steps such as cleaning, bleaching, dyeing, drying, napping, brushing, and heat-and-pressure preshrinking, and any combination of these steps. Typically, finishing and drying may be carried out at one or more temperatures below 160 ℃. Drying or heat-and-pressure pre-shrinking may be performed under the condition of warp-overfeed on the circular knitted elastic fabric of at least one of single jersey, back-loop jersey and fleece.
The circular knit, elastic fabric of at least one of single jersey, and fleece can have an elastic material content of from about 3.5% to about 30% by weight (based on total weight of fabric per square meter), typically from about 3.5% to about 27% (based on total weight of fabric per square meter), for example from about 5% to about 25% by weight (based on total weight of fabric per square meter). Further, the circular knit, elastic fabric of at least one of single jersey, and fleece may have a cover factor of about 1.05 to about 1.9, such as about 1.29 to about 1.4.
The second and third aspects of the invention are circular knit, elastic fabrics of at least one of single jersey, back loop jersey, and fleece and garments made from such fabrics made by the process of the invention. The circular knitted elastic fabric of at least one of single-sided jersey, back loop plain knit and pile prepared by the method of the invention can be made of synthetic yarns; spun yarns of natural fibers; natural fibers blended with synthetic fibers or yarns; cotton spun yarn; cotton blended with synthetic fibers or yarns; spun yarns of polypropylene, polyethylene or polyester blended with polypropylene, polyethylene or polyester fibers or yarns and combinations thereof and may have basis weights of about 100 to about 500g/m2E.g., from about 140 to about 350g/m2. The circular knit, elastic fabric of at least one of single jersey, back loop, and pile can have an elongation in the length direction (warp direction) of about 45% to about 175%, such as about 60% to about 175%, and a shrinkage of about 15% or less, typically 14% or less, such as less than about 7%, in both length and width after washing and drying. The circular knit, elastic fabric of at least one of single jersey, and fleece may have been exposed to a temperature of no more than about 160 ℃ (as indicated by differential scanning calorimetry or spandex molecular weight analysis). The circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile may be a circular cylinder (e.g., a product formed from circular knitting) or a flat knit. The fabric cylinder may be slit to provide an open width fabric. Typically the circular knit, elastic fabric of at least one of single jersey, back loop, and pile has a face curl value of about 1.0 or less, for example about 0.5 or less. Garments made from the elastic fabric of at least one of the single jersey, the jersey loop, and the pile may include swimsuits, undergarments, T-shirts, and thin or heavy clothing, such as ready-made clothes, jerseys, sweaters, and the like,Sports wear or outdoor wear.
The present invention includes a circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile having at least one elastic material incorporated therein, wherein the at least one elastic material can stretch no more than about 7 x, typically no more than 5 x, such as no more than 3 x, of its original length, and the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile can be exposed to a wet-set step prior to or during a dyeing step.
The present invention also includes a method of making a circular knit, elastic fabric having incorporated therein at least one of single jersey, back loop jersey, and pile, of at least one elastic material, wherein the method includes stretching the at least one elastic material no more than about 7 x its original length, and wherein the method includes a wet-set step and may not include a dry-heat-set step. The uncoated spandex contact points of the fabric of the invention may be fused less than about 50%, typically less than about 30%, for example less than about 10% at uncoated contact points.
The present invention also includes a circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece having at least one elastic material incorporated therein, wherein the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece can be made into a cylinder and the wash shrinkage can be less than about 15%, typically 14% or less, such as 7% or less. The knitted fabric tube may be free of side creases and the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece may be used to cut and sew into garments.
The present invention also includes a circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece made from heat sensitive tightly twisted yarn and at least one elastic material incorporated therein.
Other features and advantages of the invention will become apparent from the following detailed description, when read in conjunction with the accompanying drawings and appended claims.
Brief Description of Drawings
FIG. 1 is a schematic view of a plated knit loop containing a hard twist yarn and spandex.
Fig. 2 is a schematic view of a portion of a circular knitting machine feeding spandex feed and tight twist yarn feed.
Figure 3 is a schematic view illustrating a series of single jersey knit loops and highlighting one of the loops for the loop length "L".
FIG. 4 is a flow chart of prior art method steps for making a circular knit elastic single jersey fabric with bare spandex plated into each knitted course.
FIG. 5 is a flowchart of the method steps of the present invention for making a circular knit, elastic, single jersey fabric with an uncoated spandex plated into each knitted course, as described in U.S. Pat. No. 6,776,014.
FIG. 6 is a flowchart of the method steps of the present invention for making a circular knit, elastic, single jersey fabric with an uncoated spandex plated into each knitted course, in accordance with one embodiment of the present invention.
FIG. 7 is a flow chart of the process steps of the present invention for making a circular knit elastic back loop flat knit fabric and pile fabric with bare spandex plated into the spaced courses in accordance with one embodiment of the present invention.
Detailed Description
Before explaining at least one embodiment of the invention in detail by way of example the drawings, tests, results and test procedures, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings, tests and/or results. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, the language used herein is to be given the broadest possible scope and meaning; and embodiments are intended to be illustrative and not exhaustive. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The term "elastic material" or "elastomer" as used herein will be understood to refer to a synthetic material having the superior stretchability and recovery of natural rubber, such that the material is capable of being repeatedly stretched to at least twice its original length and forcefully recovers to approximately its original length immediately after stress release. "elastomeric materials" are generally prepared fibers wherein the fiber-forming substance is a long chain synthetic polymer having polyurethane segments. Examples of elastomeric materials that may be used in the present invention include, but are not limited to spandex (spandex), elastomers (elastane), anidex (aninedex), elastoesters, bicomponent filament rubbers, and combinations thereof.
As used herein, "spandex" refers to a fiber prepared wherein the fiber-forming material is a long chain synthetic polymer comprising at least 85% polyurethane segments. The polyurethane is prepared from a polyether diol, a diisocyanate mixture and a chain extender, and then is melt-spun, dry-spun or wet-spun to prepare spandex fibers. Preferred spandex fibers are elastomeric commercial products for circular knitting, such as LYCRA types T162B, T162C, T165C, T169B and T562Spandex fibers.
The term "denier" as used herein is to be understood as a relative measure of the linear density (or fineness) of a fiber or yarn. The denier is equal to the weight in grams of material per 9,000 meters of length. The term "dtex" as used herein is to be understood as the weight in grams equivalent to a length of 10,000 meters of material.
As used herein, "stretch" refers to the amount of stretch applied to a strand of elastic material, such as spandex, that results in a decrease in the linear density of the strand of elastic material. The stretching of the fiber is directly related to the elongation (stretch) applied to the fiber. For example 100% elongation corresponds to 2 x stretch, 200% elongation corresponds to 3 x stretch, etc.
The term "tight-twisted yarn" as used herein is to be understood as meaning a knitting yarn that does not comprise a substantial amount of elastic stretch, such as natural and/or synthetic spun yarns, natural and/or synthetic filament yarns, and combinations thereof. Examples of materials that can be used in the spun and/or spun yarn of the present invention include, but are not limited to, cotton, polyester, nylon, polypropylene, polyethylene, acrylonitrile, wool, acetate, polyacrylonitrile, and combinations thereof. Natural fibres as used herein will be understood to mean fibres such as cellulose (i.e. cotton, bamboo) or protein (i.e. wool, silk, soy) fibres.
The term "tight-twist yarn count" as used herein will be understood to refer to a measure of the fineness or linear density of the yarn. The tight twist count can be expressed in indirect units (length per unit weight or mass) or direct units (weight per unit length). In one embodiment, the tight twist yarn count is expressed as "Ne" for the english system of metrics and "Nm" for the metric system of metrics.
As used herein, the term "warp direction" refers to the lengthwise direction of the fabric, while the term "weft direction" refers to the widthwise direction of the fabric.
The term "cover factor" as used herein will be understood to refer to the ratio of fabric surface occupied by the yarn to the total fabric surface. The cover factor is a relative measure of the opening degree of each knitted loop characterizing the structural design of the circular knitted fabric. The "openness" is related to the percentage of the area of the opening in each loop relative to the area covered by the yarn. The calculation of the cover factor will be described in further detail below.
As used herein, the term "dry heat set" will be understood to refer to a step which comprises placing the fabric under tension on a tenter frame and exposing the fabric to air at a temperature in excess of about 160 ℃, typically about 175 ℃ to about 200 ℃, and a relative humidity of less than about 50% for a time sufficient to stabilize the lower denier spandex. In dry heat setting, the spandex is permanently changed at the molecular level so that the recovery tension of the stretched spandex is largely released and the spandex becomes stable at the new, lower titer.
The term "wet-set" as used herein will be understood to refer to a step in the present invention wherein the knitted fabric is subjected to hot water (e.g., at a temperature of about 105 ℃ or higher) under very low tension for a time sufficient to cause the elastic material in the fabric to change and become at least partially stabilized.
The term "fused" as used herein will be understood to mean that the uncoated spandex yarns at the point of contact in the fabric are fused together. The uncoated spandex contact points of the fabric of the invention can be fused less than about 50%, for example, the uncoated spandex contact points can be fused less than about 30%, about 10%, or about 5%.
The terms "molecular weight analysis" and "differential scanning calorimetry" as used herein refer to a method of determining the maximum temperature to which a spandex sample has been exposed. The term "molecular weight analysis" refers to a method of analyzing the molecular weight of an elastomeric material and correlating it to the thermal history of the elastomeric material. The term "differential scanning calorimetry" refers to a method of measuring the amount of energy (heat) absorbed or released by a sample when it is heated, cooled, or held at a constant temperature.
In the case of knitting structures in circular knitting machines, the process of co-knitting spandex is referred to as "plating". In the case of plating, the tightly twisted yarn and the uncoated spandex yarn are knitted in parallel, side-by-side relationship, with the spandex yarn always held on one side of the tightly twisted yarn and thus on one side of the knitted fabric. Fig. 1 is a schematic illustration of a plated knit loop 10 in which the knit yarn comprises spandex 12 and a multifilament hard twist yarn 14. When plating spandex with the hard twist yarn to produce a knit fabric, additional processing costs are incurred in addition to the additional spandex fiber cost. For example, when preparing circular knit, elastic fabrics of at least one of single jersey, back loop jersey, and pile, fabric stretching and heat setting are typically required during the finishing step.
"circular knitting" refers to a form of weft knitting in which the needles are organized into a circular knitting bed. Generally, the needle cylinder rotates and interacts with the cam to move the needles relative to each other to knit. The yarn to be knitted is fed from a package to a carrier plate which guides the yarn to the needles. The circular knitted fabric comes out from the knitting needle through the center of the cylinder in a cylindrical shape.
The steps for preparing the elastic circular knit according to the known method 40 are shown in figure 4. Although process variations exist for different fabric knit constructions and fabric end uses, the steps shown in FIG. 4 represent the preparation of a single jersey knit elastic fabric with staple tightly twisted yarn (such as, but not limited to, cotton). The fabric is the first circular knit 42 under high spandex stretch and feed tension. For example, for a single jersey fabric prepared by plating uncoated spandex to each knitted course, a known feed tension for 22dtex spandex is 2-4 cN, for 33 dtex is 3-5 cN; and 44dtex is 4-6cN (DuPont Technical Bulletin L410). The fabric is knitted into a cylinder which is collected under the knitting machine either onto a rotating mandrel into a flat cylinder or into a box after it is loosely folded back and forth (i.e., folded).
In the open-width finishing, the knitting cylinder is then cut 44 and laid flat. The open fabric is then relaxed 46, or wetted (padded) by passing it through steam or by impregnation and pressing. The relaxed fabric is then placed on a tenter frame and heated in an oven (heat set 46). Tenter frames hold the fabric edges by needles and stretch it in both the length and width directions to return the fabric to the desired size and basis weight. This heat-setting is done prior to the subsequent wet processing step, and is thus commonly referred to in the art as "pre-setting". At the oven exit, the flat fabric is released from the tenter frame and then its tack 48 (sewn) is returned to the cylindrical shape. The fabric is then processed in a drum through wet processing 50 of cleaning (washing) and optionally bleaching/dyeing (e.g., by slow-flow spray equipment), followed by dewatering 52 (e.g., by squeeze rolls or in a centrifuge). The fabric is then "separated" 54 by removing the sewing thread and reopened to a flat piece. The flat, still wet fabric is then dried/heat-set 56 in a tenter oven under fabric overfeed (as opposed to stretching) so that the fabric is not under tension in the lengthwise (machine) direction while drying at a temperature below the heat-set temperature. A slight tension is applied to the fabric in the width direction to smooth out any possible wrinkles. An optional fabric finish such as a softener may be applied just prior to the drying/heat-setting process 56. In some cases, the fabric finish is applied after the fabric is first dried by a belt or tenter oven so that the finish is uniformly absorbed by the equally dried fibers. This additional step involves rewetting the dried fabric with a finish and then drying the fabric in a tenter oven.
Heat setting of the dry fabric in a tenter frame or other drying apparatus "sets" the spandex in the stretched state. This is also referred to as remaking, where higher denier spandex fibers are drawn to lower denier and then heated to a sufficiently high temperature for a sufficient time to stabilize the spandex at the lower denier. Thus heat-set means that the spandex is permanently altered at the molecular level so that the recovery tension of the stretched spandex is mostly released and the spandex becomes stable at the new lower denier. The heat-set temperature of spandex fibers is typically from about 175 ℃ to about 200 ℃. For the well known prior art process 40 shown in fig. 4, the heat setting 46 is typically about 190 c for about 45 seconds or more.
Loop compression in knits has three major effects directly related to the performance of elastic knits, thus generally making the fabric unsuitable for subsequent cutting and sewing processes.
First, the coil compression reduces the fabric size and the basis weight (g/m) of the fabric2) To a desired extent beyond circular knit elastic fabrics for at least one of single jersey, back loop jersey, and pile for clothing. Thus, the traditional finishing process for elastic circular knit fabrics involves a fabric stretching and heating step that is carried out at a sufficiently high temperature for a sufficiently long dwell time so that the spandex yarn in the knit will "set" at the desired stretch dimensions. After heat-setting, the spandex yarn either does not shrink, or only shrinks appreciably, below its heat-set size. Thus, the heat-set spandex yarn will not significantly compress the knit loop away from the heat-set dimension. The stretch and heat-set parameters are selected to give the desired basis weight and elongation of the fabric within relatively tight limits. For a typical cotton jersey stretch jersey knit, the elongation is at least 60% and the basis weight is about 140-about 500g/m2。
Second, the more coil compression, the more the fabric stretch percentage, and thus greatly exceeds the minimum standards and practical needs. When comparing a plated knitted fabric containing an elastic yarn with a knitted fabric containing no elastic yarn, typically the plated elastic knitted fabric is 50% shorter (more compressed) than a fabric containing no elastic yarn. The plated knit fabric can be stretched 150% or more in length from this compressed state, and such over-extension is generally not required in jersey knits for cut and stitch applications. The length is in the warp direction of the fabric. High length stretch fabrics are more prone to trim irregularities and also to excessive shrinkage during laundering. Also, the stitches are compressed in the width direction by the spandex fibers, thereby reducing the fabric width by about 50%, well beyond the typical 15-20% knitted width reduction of stiff (inelastic) fabrics.
Third, the compressed loops in the finished fabric are in a balance between spandex fiber recovery force and the loop compression resistance of the companion tightly twisted yarn. Washing and drying of the fabric may reduce the resistance of the tightly twisted yarn, possibly in part due to agitation of the fabric. Thus, washing and drying may allow the spandex fiber restoring force to further compress the knit loops, which may result in unacceptable levels of fabric shrinkage. The knit fabric is heat set for relaxation of the spandex and to reduce spandex recovery force. The heat-setting process thus improves the stability of the fabric and reduces the amount of shrinkage of the fabric after repeated washings.
The subject of the present invention is the preparation of circular knitted elastic fabrics of at least one of single jersey, back loop jersey and fleece, circular knitted and in particular for subsequent "cut and sew" use. These knitted elastic fabrics are prepared from an elastic material and a tightly twisted yarn, wherein the elastic material is stretched to no more than about 7 x and the knitted elastic fabric is subjected to a wet-set step without being subjected to dry heat-set. The obtained fabric has excellent properties with respect to the known fabrics, since about 100g/m is obtained2-about 400g/m2Reduced fabric shrinkage and acceptable fabric elongation. In addition, when toFinal weight of about 100g/m2-about 400g/m2The fabric of (a) was found to have improved fabric curl when wet set.
The invention also relates to a method of making a circular knit, elastic fabric comprising at least one of a single jersey, a back loop jersey, and a pile of spandex and polypropylene tightly twisted yarns without dry heat setting. The present invention provides a novel method of making spandex-polypropylene knit fabrics, since polypropylene fibers cannot be heat-set at the temperatures required to permanently deform the spandex. The obtained fabric has excellent properties with respect to the known fabrics, since about 140g/m is obtained2-about 400g/m2Reduced fabric shrinkage and acceptable fabric elongation. Furthermore, when the final weight is 150-400g/m2The fabric of (a) was found to have improved fabric curl when wet set.
With respect to circular knitting, fig. 2 shows a schematic view of one feed position 20 of a circular knitting machine with a series of knitting needles 22 which move relative to each other as indicated by the arrow 24 in response to cams (not shown) under a rotating needle cylinder (not shown) which grip the needles. In circular knitting machines, there are a plurality of such feed locations arranged in a circle so as to be fed to the respective knitting locations as the needles carried by the moving needle cylinder rotate past the knitting locations.
In the case of the plating knitting process, the spandex yarn 12 and the tight twist yarn 14 are fed to the knitting needle 22 through the carrier sheet 26. The carrier sheet 26 simultaneously guides both yarns to the weaving position. The spandex yarn 12 and the tightly twisted yarn 14 are introduced at the same or similar rate into the needle 22 to produce the single jersey knit loop 10 shown in fig. 1.
Although the drawings may be described herein using spandex yarn, it should be understood that the use of spandex yarn in the following description is for illustration only, and thus the invention is not limited to the use of spandex. Rather, any elastic material can be substituted for the spandex fiber of the present invention and is within the scope of the present invention. While the use of other elastic materials may require parameters outside of the ranges described herein, it is to be understood that one of ordinary skill in the art will readily be able to determine the required parameters for alternative elastic materials in light of the present teachings and disclosure, and thus such parameters are fully within the scope and teachings of the present invention.
The tightly twisted yarn 14 from the winding package 28 is fed to an accumulator 30 which meters the yarn to the carrier plate 26 and the knitting needle 22. The tightly twisted yarn 14 passes through a feed roller 32 and through a yarn guide aperture 34 in the carrier plate 26. Optionally, more than one tightly twisted yarn may be delivered to the knitting needles through different yarn guide holes in the carrier plate 26. With the back loop jersey fabric construction of the present invention, two tightly twisted yarns can be knitted with one elastic yarn. One ply of the tight-twist yarn is plated with the elastic yarn and a second ply of the tight-twist yarn is laid into the fabric as shown in fig. 2. As such, the plated jersey and back loop jersey yarns are alternately fed into the machine. The pile fabric is prepared from a back loop plain knitted fabric subjected to a napping finishing step. The preparation of back loop jersey and pile fabrics is well known to those skilled in the art.
The spandex 12 is delivered from the surface drive package 36 and passes through a break detector 39 and a reversing roller 37 to a guide groove 38 in the carrier plate 26. The feed tension of the spandex 12 is measured between the detector 39 and the drive roll 37, or between the surface drive package 36 and the roll 37 if a break detector is not used. The guide holes 34 and guide slots 38 in the carrier plate 26 are spaced apart to deliver the tightly twisted yarn 14 and spandex fiber 12 in side-by-side, generally parallel relationship (plating) to the needle 22.
Stretching of the spandex occurs when it is transferred from the supply package to the carrier plate and in turn to the knitting loops, due to the difference between the rate of stitch use and the feed rate of the spandex supply package. The ratio of the tight yarn feed rate (meters per minute) to the spandex feed rate is typically from about 2.5 to about 4 times or more and is known as mechanical drawing. This corresponds to spandex elongations of about 150% to about 300% or more. The feed tension of the spandex yarn is directly related to the draw (elongation) of the spandex yarn. In the case of spandex, this feed tension is generally maintained at a value consistent with high mechanical draw.
The present invention has been made clear: improved results over the prior art are obtained when the spandex total stretch (measured in the fabric) is maintained at about 7 x or less, typically 3 x or less, e.g., 2.5 x or less. The draw value is the total draw of the spandex, which includes any spandex draw contained in the as-spun yarn supply package. The residual stretch value from spinning is known as package relaxation "PR" and is typically from about 0.05 to about 0.15 for a spandex for a circular knit elastic fabric of at least one of single jersey, back loop jersey, and pile. The total stretch of the spandex in the fabric is therefore MD (1+ PR), where "MD" is the needleloom stretch. Knitting machine draw is the ratio of the tight yarn feed rate to the spandex feed rate, both from their respective supply packages.
Due to its stress-strain properties, spandex yarn stretches more as the tension applied to the spandex increases; conversely, the more spandex stretch, the higher the tension in the yarn. The typical spandex yarn path in a circular knitting machine is shown diagrammatically in fig. 2. The spandex yarn 12 is metered from a supply package 36, over or past a break detector 39, past one or more reversing rollers 37, and then to a carrier plate 26, which guides the spandex yarn 12 to the needle 22 and into the stitch. As the spandex yarn 12 passes from the supply package 36 through each device or roll, tension in the spandex yarn 12 can build up due to frictional forces caused by each device or roll contacting the spandex yarn 12. The total draw of the spandex yarn 12 in the coil is therefore related to the sum of the tensions throughout the spandex path.
The spandex feed tension is measured between the break detector 39 and the roller 37 shown in fig. 2. Alternatively, if the break detector 39 is not used, the spandex feed tension is measured between the surface drive package 36 and the roller 37. The higher the tension that is fixed and controlled, the greater the spandex stretch in the fabric, and vice versa. The prior art teaches that: in a commercial circular knitting machine, the feed tension should be about 2 to about 4 cN for 22dtex exspandex; and for 44dtex spandex, the feed tension should be about 4 to about 6 cN. Due to these feed tension settings and other tensions imposed by friction in the yarn path following, spandex (e.g., 44dtex) in, for example, a commercial knitting machine, will stretch significantly more than about 3 x.
The invention does not always anticipate that the spandex friction between the supply package and the loops of knitting can be minimized. However, this process requires that friction be minimized to keep the spandex feed tension high enough to ensure reliable spandex feeding while maintaining spandex stretch to about 7 x or less, typically 3 x or less, for example about 2.5 x or less.
After a circular knit elastic fabric of at least one of single jersey, jersey back knit, and fleece is plated with spandex and hard twist yarn by the process of the present invention, the fabric is finished in any of the alternatives illustrated in fig. 6 and 7.
A second aspect of the present invention is a hot water setting treatment 74 (or 94) which may be performed just before or just after the washing and bleaching step 64 (or 84) (in fig. 6 and 7, respectively). Treating said fabric with hot water in a spray dryer for about 5 to about 90 minutes at a temperature of about 105 ℃ to about 145 ℃ under a pressure of no more than about 4.0kg/cm2. In the wet-set process, the fabric can be passed through the nozzle as quickly as it is dyed, but without the addition of dye. Alternatively, the wet-setting step may comprise contacting the fabric with an aqueous dye solution. In the jet dryer, the circular tubular knitted fabric is moved in and out of the liquid bath by the action of a venturi nozzle, which advances the fabric with a bath of liquid (or air). In this wet-set process 74 (or 94), the spandex fibers within the fabric are exposed to hot and humid conditions such that the spandex properties change. The fiber fineness and the fiber elastic strength decrease. The spandex load power after wet-set is reduced by about 40% and the unload force is reduced by about 20% relative to the non-wet-set fiber. The fabric is then dyed or washed in the same spray dryer, route 65a or 65d in fig. 6 (route 85a or 85d in fig. 7). Alternatively, the fabric may be dyed prior to the wet-set step, route 65b or 65c in fig. 6 (85 b or 85c in fig. 7). If a wet-set step is not employed as in lanes 63a and 63b of FIG. 5, the basis weight of the finished fabric will be higher, as shown in the examples.
The drying process 70 may be performed on circular knit elastic single jersey fabrics in open width webs (the upper two rows of the figure, lanes 65a and 65c) or in tubular form (the lower two rows of the figure, lanes 65b and 65 d). For either route, a wet finishing process 64 (e.g., washing, bleaching and/or dyeing) is performed on the circular knit elastic single jersey fabric when it is cylindrical. One form of dyeing, known as soft jet dyeing, generally imparts tension and some length deformation to circular knit elastic single jersey fabrics. Care should be taken to minimize any additional tension applied during the fabric processing and to transfer from wet-finish to the dryer, while at the same time allowing the circular knit elastic single jersey fabric to relax during drying and recover from such wet-finish and transfer tension.
After the wet finishing process step 64, the circular knit, elastic, single jersey fabric is dewatered 66, such as by pressing or centrifuging. In lanes 65a and 65c, the cylindrical fabric is slit 68 for optional finishing applications (e.g., softener application by padding) and then dried in a tenter oven under fabric length overfeed conditions before being sent to a finishing/drying step 70. In the processing lines 65b and 65d, the cylindrical fabric is not cut but is conveyed as a cylinder to the finishing/drying step 70. Finishes (e.g., softeners) may optionally be applied by padding. The cylindrical fabric is conveyed through a drying oven, such as on a belt, and then to a pre-compactor to independently provide fabric overfeeding. The pre-shrinking machine typically employs rollers to transport the fabric (typically in a steam atmosphere). The first roller is driven at a faster rotational speed than the second roller so that the fabric has an overfeed. Typically, the steam does not "rewet" the fabric so that no additional drying is required after the preshrinking.
The drying step 70 (lanes 65a and 65c) or the preshrinking step 72 (lanes 65b and 65d) is performed under controlled, lengthwise (machine direction) high fabric overfeed conditions so that the fabric loops move and rearrange freely without tension. After drying, a flat, wrinkle-free or kink-free fabric is present. Those skilled in the art are familiar with these techniques. In the case of open width fabrics, a tenter frame is used to provide overfeeding of the fabric during the drying process. For cylindrical fabrics, after the belt is dried, a forced overfeed is typically provided in a pre-compactor 72. In open or cylindrical fabric processing, the fabric drying temperature and residence time are set at values below the desired values for the heat-set spandex.
The back loop jersey and fleece are knitted, wet finished and wet set similar to single jersey fabrics, fig. 7. For open width finishing, the tubular fabric is cut 88. In the finishing/drying step 90, the pile aid is padded to the fabric. In the case of open width pile fabrics, after drying, the raising step 100 and final finishing are carried out by a tenter 102. In the case of a finished flat back loop jersey fabric, the raising 100 and final finishing 102 steps are not required. In the case of a tubular-shaped finished fabric, the tubular fabric is not cut but is conveyed as a cylinder to the finishing/drying step 92. The cylindrical fabric is conveyed through a drying oven, such as by being laid on a belt. In the case of a cylindrical pile fabric, drying is followed by a napping step 104 and a final preshrinking step 106. In the case of a back loop jersey, the fabric tube is turned inside out 104 and pre-shrunk 106.
The drying step 90 (or 92) or the preshrinking step 106 (or the finishing step 102) is carried out under controlled, high fabric overfeed lengthwise (machine direction) so that the fabric loops are free to move and rearrange without tension. After drying, a flat, wrinkle-free or kink-free fabric is present. Those skilled in the art are familiar with these techniques. In the case of open width fabrics, a tenter frame is used to provide overfeeding of the fabric during the drying process. In the case of a cylindrical fabric, after tumbling or napping, a forced overfeed is typically provided in the pre-compactor 106. In open or cylindrical fabric processing, the fabric drying temperature and residence time are set at values below the desired values for the heat-set spandex.
The structural design of a circular knit, elastic fabric of at least one of single jersey, and fleece may be characterized in part by the "openness" of each knit loop. The "openness" is related to the percentage of the area of each loop opening relative to the area covered by the yarn (see, e.g., figures 1 and 3), and thus to the fabric basis weight and potential elongation. In the case of stiff inelastic weft knitted fabrics, the cover factor ("Cf") is well known as a relative measure of openness. The cover factor is a ratio and is defined as:
Cf＝√(tex)÷L
where tex is the grammage of the 1000 meter tightly twisted yarn and L is the loop length in millimeters. Figure 3 is a schematic view of a single knit jersey loop pattern. One coil in the pattern has highlighted how the coil length "L" is defined. For yarns with a metric count Nm, tex is 1000/Nm, and the cover factor is either as follows:
Cf＝√(1000/Nm)÷L
one embodiment of the present invention describes the preparation of a commercial circular knit elastic fabric from an uncoated elastomeric material, such as at least one of an uncoated spandex and a tight-twisted plated single jersey, back loop jersey, and fleece, by maintaining the elastomeric material at a stretch of about 7 x or less, typically 3 x or less, such as 2.5 x or less, without a dry heat setting step, and designing and preparing the knit fabric according to the following principles:
-a cover factor, which characterizes the openness of the knitted structure, of about 1.05 to about 1.9, for example about 1.14 to about 1.6;
-a tightly-twisted yarn count Nm of from about 165 to about 10, such as from about 68 to about 44, typically from about 54 to 47;
-the elastic material is about 15 to about 156dtex, such as about 22 to about 78 dtex;
the content of elastomeric material (in% by weight) in the circular knit elastic single jersey, back loop jersey or fleece is from about 3.5% to about 30%, and typically from about 3.5% to about 27%, for example from about 5% to about 25%;
the knitted fabric may be subjected to a heat moisture setting treatment in a spray dryer at a temperature of from about 105 ℃ to about 145 ℃ for a period of from about 5 to about 90 minutes;
-the circular knit elastic fabric of at least one of single jersey, back loop jersey, and pile thus produced has a crimp value of 1.0 or less;
-the circular knit, elastic fabric of at least one of single jersey, back loop jersey, and pile so produced has a shrinkage after washing and drying of about 15% or less, typically 14% or less, for example 7% or less, in the length and width directions;
-said circular knit elastic fabric of at least one of single jersey, back loop jersey, and pile has an elongation in the length (warp) direction of from about 35% to about 175%, such as from about 60% to about 175%; and
the tightly twisted yarn is a synthetic filament (e.g. polypropylene or polyester); natural fiber spun yarn; natural fibers blended with synthetic fibers or yarns (e.g., polypropylene or polyester); cotton spun yarn; cotton blended with synthetic fibers or yarns; polypropylene, polyethylene or polyester staple yarns blended with polypropylene, polyethylene or polyester fibers or yarns and combinations thereof.
While not wishing to be bound by any theory, it is believed that the tightly twisted yarns in the knit structure resist the spandex force that compresses the knit loops. The efficiency of this resistance is related to the knit structure (defined by the cover factor). For a given tightly twisted yarn count Ne, the cover factor is inversely proportional to the loop length L. This length can be adjusted on the knitting machine and is therefore a critical variable for control.
Since the elastic material is not heat-set in the method of the present invention, the elastic material stretch should be the same within the measurement error limits in the circular knit elastic fabric of at least one of single jersey, back loop jersey, and fleece, finished fabric, or in an intermediate fabric processing step.
In the case of a circular knit elastic fabric of at least one of single jersey, back jersey, and fleece, a suitable knitting machine gauge is selected in accordance with the prior art relationship between the number of tight-twisted yarns and the knitting machine gauge. For example, the gauge may be selected to optimize the basis weight of a circular knit elastic fabric of at least one of single jersey, back loop jersey, and fleece.
In the circular knitted elastic fabric of at least one of the back loop plain knit fabric and the pile, the at least two types of tightly twisted yarns may be different. In the circular knitted elastic fabric of at least one of the back loop plain knit fabric and the pile, the at least two tightly twisted yarns may be the same.
The advantages of the present invention are apparent when comparing the prior art method illustrated in fig. 4 with the method of the present invention illustrated in fig. 6 and 7. Conventional knitting and finishing requires additional processing steps, additional equipment, and a significantly more labor intensive process than the alternative method of the present invention shown in fig. 6 and 7. Furthermore, by eliminating the high temperature dry heat setting previously required (see FIG. 4), the process of the present invention reduces heat damage to fibers (e.g., cotton), requires less or no bleaching, and thus improves the "hand" of the finished fabric. As for other benefits, heat sensitive tightly twisted yarns can be used in the process of the present invention to make circular knit elastic fabrics of at least one of single jersey, back loop jersey, and fleece, thereby increasing the possibility of different and improved products.
A softener is optionally used, but is typically applied to the circular knit elastic fabric of at least one of single jersey, back loop jersey, and pile to further improve fabric hand and to increase the mobility of the loops during drying. Typical softeners such as SURSOFTSN (Surry chemical) or SANDOPERMSEI(CLARIANT). A circular knit, elastic fabric of at least one of single jersey, back loop jersey, and fleece may be passed through a tank containing a liquid softener composition and then through a nip between a pair of nip rollers (padding rollers) to squeeze excess liquid from the fabric.
Another surprising advantage of the present invention is that the circular knit elastic single jersey fabric produced by the process of the present invention and collected by folding (plaiting) does not crease to the same extent as prior art circular knit single jersey fabrics. Few or fewer visible creases in the finished fabric result in increased yields for cutting and sewing the fabric into garments. Also surprisingly, the "skewing" of the circular knit elastic single jersey fabric of the present invention is significantly reduced. The reduction of the skewness of the weft is realized through open-width or cylindrical finishing processing. If the degree of skewing or turning of the fabric is increased, the fabric is diagonally deformed and the courses are "bias". Garments made with bias fabrics tend to twist on the body and are not suitable for use.
The following examples illustrate the invention and its benefits. The invention is capable of other different embodiments and its several details are capable of modifications in various obvious aspects all without departing from the scope and spirit of the present invention. The embodiments themselves are, therefore, to be considered in all respects as illustrative and not restrictive.
Examples
Fabric knitting and finishing
Circular knit elastic fabrics of at least one of single jersey, jersey back loop, and fleece for the examples, plated with tight twist, bare spandex, were knit on the following devices: (1) PL-FS3B/T Pai Lung circular knitting machine with a cylinder diameter of 16 inches, a 28 gauge cylinder (needles/inch circumference) and 48 feed locations; (2) PL-XS3B/C Pai Lung circular knitting machine with a needle cylinder diameter of 26 inches, a needle cylinder number 24 and 78 feed positions; or (3) a Monarch circular knitting machine of the VXC-3S type, with a 30-inch diameter cylinder, a No. 20 cylinder and 90 feed positions. Machines 28 and 20 run at 24 revolutions per minute (rpm), while machine 24 runs at 26 rpm.
For these embodiments, the break detector in each spandex feed line (see FIG. 2) is either adjusted to reduce sensitivity to yarn tension or removed from the machine. The break detector is of the type that contacts the yarn and thereby senses the tension in the spandex.
The spandex feed tension is measured between the spandex supply package 36 and guide roll 37 (FIG. 2) using a Zivy digital tensiometer (model: EN-10). For 20 and 30 denier spandex, the spandex feed tension is maintained at 1 gram or less. These tensions are high enough to reliably and continuously feed spandex yarn to the needles and low enough to stretch only spandex about 2 x or less. It has been determined that: when the feed tension is too low, the spandex yarn is wound around the guide rolls at the supply package and cannot be reliably fed into the circular knitting machine.
In addition to examples 1, 4, 7, 10, 13, 16, 19, 22, 25, 27, 29, 31 and 33-40, other knit fabric examples were not wet set and were finished by open width method 63a of fig. 5 or as a cylinder according to method 63 b. Knit fabric examples 1, 7, 13, 19, 27, 29 and 31 were finished according to the method of route 63 a. Knit fabric examples 4, 10, 16, 22 and 25 were finished according to the method in route 63 b. The remaining knitted fabric embodiments are washed and wet-set (or wet-set and washed), dyed and dried by either the open width process 65a and 65c in fig. 6 or as a cylinder by the process of 65b and 65 d. Knit fabric examples 2, 3, 8, 9, 14, 15, 20, 21, 28 and 30 were finished according to processing line 65 a. Knit fabric examples 5, 6, 11, 12, 17, 18, 23, 24, and 26 were finished according to processing line 65 b. Knit fabric example 32 was finished according to processing route 65 c. Knit fabric embodiments 33-40 are finished according to process line 85b of FIG. 7.
Examples 1 to 32:
the fabrics were washed and bleached in 300 l of solution at 100 ℃ for 30 minutes. All these wet jet finishes (including dyeing) were carried out in a TGRU-HAF-30 type Tong gen machine (taiwan). The aqueous solution contained Stabilizer SIFA (300g) (silicate-free base), NaOH (45%, 1200g), H2O2(35％，1800g)、IMEROL ST(CLARIANT600g) (for washing), ANTIMUSSOLHT2S(Clariant，150g) (for defoaming) and IMACOLS(CLARIANT150g) (for anti-wrinkle). After 30 minutes, the solution and fabric were cooled to 75 ℃ and then the solution was drained. The fabric was then neutralized for 10 minutes at 60 ℃ in a 300 liter solution of water and HAC (150g) (hydrogen + dona, acetic acid). After washing, fresh water is added to the nozzle to perform the wet-set step 74 in FIG. 6. The fabric and water at about 105 c to about 140 c are run in the nozzle for about 15 to about 90 minutes.
The fabric was dyed with reactive dyes and other components in 300 l of aqueous solution at 60 ℃ for 60 minutes. The staining solution comprises R-3BF (CLARIANT)，215g)、Y-3RF(CLARIANT，129g)、Na2SO4(18,000g) and Na2CO3(3000g) In that respect After 10 minutes, the dye bath was drained and refilled to neutralize with HAC (150g) for 10 minutes at 60 ℃. After neutralization, the bath was drained and refilled with fresh water for 10 minutes of washing. After neutralization, a further 300 l container was filled with water and 150g of Sandopur RSK (Clariant) was addedSoap). The solution was heated to 98 ℃ and the fabric was washed/soaped for 10 minutes. After draining and another 10 minutes of rinsing, the fabric was removed from the container.
The wet fabric was then dewatered by centrifugation for 8 minutes. For the final step, the liquid mixture is mixed with a SANDOPERM SEI liquid (CLARIANT)1155g) of a lubricant (softener) was padded onto the fabric. Then tenteringThe fabric was dried in an oven at 145 ℃ with a 50% overfeed for about 30 seconds. The above steps and additives will be familiar to those skilled in the art of textile manufacture and circular knitting of single jersey, back loop flat or pile knits.
Examples 33 to 40
Examples 33-40 were bleached and wet-set in a jet dyeing machine (Scholl sample jet rd, Scholl-Then, Safenwil, Switzerland) for 20 minutes at 95 ℃. The concentrations of the components in the bleaching liquor (by weight of the fabric) were as follows: 8% owf hydrogen peroxide, 1% owf Stabilon EZY(CIBA Specialty Chemicals, High Point, North Carolina) and acetic acid for neutralization. The bath ratio was 1: 8. The bleach bath temperature was increased from 49 ℃ to 95 ℃ at a rate of 4 ℃/minute. The process was carried out at 95 ℃ for 20 minutes and then cooled to 63 ℃ at a cooling rate of 7 ℃/minute. The bleaching bath was then drained and the machine was recharged with 49 ℃ water, heated to 77 ℃, run for 8 minutes and drained. The bath was once more charged with 49 ℃ water, neutralized with acetic acid at 77 ℃ for 8 minutes and drained. The bath was again charged with 49 ℃ water, heated to 120 ℃ at a rate of 5 ℃/min and wet set for 20 minutes (examples 33, 35, 37 and 39). Examples 34, 36, 38 and 40 were wet set at 130 ℃ for 20 minutes. The temperature was cooled to 38 ℃ at a rate of 7 ℃/min and then drained. The wet web is then dewatered by squeeze rolls as is normal practice. For examples 37-40, the fabric was dried loosely with maximum overfeeding at 143 ℃ using a belt relaxation dryer (TUBETEX, Tubular Textile Group, Lexington, North Carolina). The fabric was turned inside out and steam-prefixed (TUBETEX, Tubular Textile Group, Lexington, North Carolina) at 149 ℃ with 4% overfeed. For examples 33-36, the fabrics were padded with a pile aid (American Textile specialties, Spartanburg, South Carolina) and dried with maximum overfeed relaxation using a belt relaxation dryer (TUBETEX, Tubular Textile Group, Lexin gton, North Carolina) at 143 ℃. Double-acting by Gessner LynxA series napper (The Gessner Company, Charlton, Massachusetts) napps four times on one side of The fabric. As a final step, the fabric was steam-shrunk (TUBETEX, Tubular Textile Group, Lexington, North Carolina) at 149 ℃ with 4% overfeed.
Analytical method
spandex stretch-the spandex stretch in the examples was measured using the following procedure (conducted at 20 ℃ and 65% relative humidity).
-unraveling a 200-stitch (needle) yarn sample from a single course and separating the spandex and the tight-twisted yarn of the sample. The longer sample was disassembled, but the beginning and end of the 200 coils were marked.
Each sample (spandex or tight-twisted yarn) was freely suspended by attaching one end to the meter ruler, so that one mark was on top of the meter ruler. Weights (weight) were attached to each sample (0.1 g/denier for tightly twisted yarn, 0.001 g/denier for spandex). The weight was lowered slowly so that the weight was applied to the end of the yarn sample without impact.
-recording the length measured between the marks. This measurement was repeated for 5 samples of each spandex and tight-twisted yarn.
-calculating the average spandex stretch according to the formula:
stretch (length of tight twist yarn between marks)/(length of spandex yarn between marks).
If the fabric is heat set, as in the prior art, it is generally not possible to measure spandex stretch in the fabric. This is because the high temperature required for spandex heat setting will soften the spandex yarn surface and the uncoated spandex will stick to itself at the coil crossover points 16 within the fabric (fig. 1). Due to these multiple points of adhesion, the fabric courses cannot be broken and the yarn sample pulled.
Weight of fabricStamping the knit sample with a 10cm diameter die. Each cut knit sample was weighed in grams. However, the device is not suitable for use in a kitchenThe "fabric weight" was then calculated as grams per square meter.
spandex fiber content-manually unraveling the knitted fabric. The spandex and accompanying tightly twisted yarn were separated and weighed with a precision laboratory balance or a torsion balance. The spandex content is expressed as a percentage of spandex weight to fabric weight.
Elongation of fabricElongation is measured only in the warp direction. Three fabric samples were used to ensure consistency of results. A fabric sample of known length was mounted on a static tensile tester and a weight representing a 4 newton/cm length load was attached to the sample. The sample was manipulated three times by hand (exercise) and then left hanging freely. The tensile length of the loaded sample was then recorded and the fabric elongation calculated.
Shrinkage rateTwo samples, each 60X 60 cm, were taken from the knitted fabric. Three dimensional marks are drawn near each edge of the fabric square and the distance between the marks is marked. The samples were then machine washed 3 times in sequence at 40 ℃ water temperature for 12 minutes each wash cycle and air dried on a table in a laboratory environment. The distance between the size marks is then measured again to calculate the amount of shrinkage.
Degree of curling of cloth surfaceA 4 inch by 4 inch (10.16cm by 10.16cm) square sample was cut from the knit. A small circle point is placed at the center of the square, and an "X" is drawn with this point as the center. The legs of the "X" are 2 inches (5.08cm) long and coincide with the outer corners of the square. The X was carefully cut out with a knife, and then the fabric face curl of two inner points generated by shearing was measured immediately, and then measured again after 2 minutes and averaged. If the fabric point is completely curled within a 360 ° circle, the curl rating is 1.0; if it is only 180 °, the crimp rating is 1/2, and so on. A crimp value of 3/4 or less is acceptable.
Molecular weight analysisThe molecular weight of spandex fiber was determined by the following method. Agilent Technologies 1090 LC (liquid chromatography, Agilent technology) is usednologices, PaloAlto, CA) equipped with a UV detector (equipped with a 280 nm filter in a filter photometric detector) and a 2 photo gel column (300mm x 7.8mm, 5 micron styrene and divinylbenzene column packing in a linear/mixed bed (phenoomex, Torrance, CA) to analyze the molecular weight of the spandex polymer. The sample was run in the mobile phase at 60 ℃ column temperature at a flow rate of 1 ml/min. Analytical samples were prepared using 2.0-3.0 mg polymer/ml solvent. A 50tl sample polymer solution was injected into the LC for analysis. Using VISCOTEKThe resulting chromatographic data were analyzed by 250 GPC software (Viscotek, Houston, TX).
The LC was calibrated using Hamielec generalized standard calibration method. Generalized standards weight average molecular weights (104,000 daltons) and number average molecular weights (33,000 daltons) were well characterized prior to use as standards.
Differential scanning calorimetryThe method introduces 4 temperatures into the same spandex sample without removing the sample from the Differential Scanning Calorimeter (DSC). The DSC instrument is a Pyres model 1 Perkin Elmer differential scanning calorimeter commercially available from Perkin Elmer (Wellesley, MA). The instrument was set to 50 ℃ start and heated to 140, 160, 180 and 200 ℃ for 1 minute at each temperature. The sample was cooled to an initial temperature of 50 ℃ after scanning each endotherm and then held at 50 ℃ for 5 minutes before scanning the next higher temperature.
The sample was then scanned from 50 ℃ to 240 ℃ to determine the endotherm generated in the previous test. Each endotherm was measured at. + -. 3 ℃ C (Each endotherm was found. + -. 3 ℃ C.). The difference between the endothermic measurement and the introduced temperature is within the tolerance of the DSC instrument.
Examples
The knitting conditions of the knitted fabrics of the examples are listed in table 1 below. Using LYCRA of type T162C, T169B or T562BSpandex was fed as Spandex. LYCRAThe Spandex denier was 55, 40 and 20 denier or 61dtex, 44dtex and 22dtex, respectively. For examples 29-32, the filaments had a number of 72, a denier per filament of 1.39 and a drying temperature of 130 ℃. The coil length L is machine set. The machine gauge was 28 needles per inch. Table 2 below summarizes key test results for the finished fabric. The curl values for all test conditions are acceptable and are not discussed further below. The spandex feed tension is listed in grams. 1.00 g equals 0.98 centiNewtons (cN).
TABLE 1 knitting conditions
| Examples | LYCRASpandex species | LYCRASpandex denier | Type of tightly twisted yarn | Number of tight-twisted yarns Nm | Coil Length L (mm) | Cloth cover coefficient Cf | LYCRASpandex feeding tension gram | Machine gauge needle/inch |
| 1 | T169B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 1.50 | 28 |
| 2 | T169B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 1.50 | 28 |
| 3 | T169B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 1.50 | 28 |
| 4 | T169B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 1.50 | 28 |
| 5 | T169B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 1.50 | 28 |
| 6 | T169B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 1.50 | 28 |
| 7 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 2.05 | 28 |
| 8 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 2.05 | 28 |
| 9 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 2.05 | 28 |
| 10 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 2.05 | 28 |
| 11 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 2.05 | 28 |
| 12 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 2.05 | 28 |
| 13 | T169B | 20 | Nylon | 64 | 3.06 | 1.29 | 1.70 | 28 |
| 14 | T169B | 20 | Nylon | 64 | 3.06 | 1.29 | 1.70 | 28 |
| 15 | T169B | 20 | Nylon | 64 | 3.06 | 1.29 | 1.70 | 28 |
| 16 | T169B | 20 | Nylon | 64 | 3.06 | 1.29 | 1.70 | 28 |
| 17 | T169B | 20 | Nylon | 64 | 3.06 | 1.29 | 1.70 | 28 |
| 18 | T169B | 20 | Nylon | 64 | 3.06 | 1.29 | 1.70 | 28 |
| 19 | T562B | 20 | Nylon | 64 | 3.06 | 1.29 | 2.90 | 28 |
| 20 | T562B | 20 | Nylon | 64 | 3.06 | 1.29 | 2.90 | 28 |
| 21 | T562B | 20 | Nylon | 64 | 3.06 | 1.29 | 2.90 | 28 |
| 22 | T562B | 20 | Nylon | 64 | 3.06 | 1.29 | 2.90 | 28 |
| 23 | T562B | 20 | Nylon | 64 | 3.06 | 1.29 | 2.90 | 28 |
| 24 | T562B | 20 | Nylon | 64 | 3.06 | 1.29 | 2.90 | 28 |
| 25 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 28 | |
| 26 | T562B | 20 | Cotton | 54.5 | 3.06 | 1.40 | 28 | |
| 27 | T562B | 40 | Cotton | 54.5 | 3.06 | 1.40 | 28 | |
| 28 | T562B | 40 | Cotton | 54.5 | 3.06 | 1.40 | 28 | |
| 29 | T162C | 55 | Polypropylene | 90 | 2.91 | 1.14 | 28 | |
| 30 | T162C | 55 | Polypropylene | 90 | 2.91 | 1.14 | 28 | |
| 31 | T162C | 70 | Polypropylene | 90 | 2.91 | 1.14 | 24 | |
| 32 | T162C | 70 | Polypropylene | 90 | 2.91 | 1.14 | 24 | |
| 33 | T562B | 30 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 34 | T562B | 30 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 35 | T562B | 20 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 36 | T562B | 20 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 37 | T562B | 30 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 38 | T562B | 30 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 39 | T562B | 20 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 | |
| 40 | T562B | 20 | Cotton (two strands) | 50&34 | 3.07 | 1.45 | 20 |
TABLE 2 results
| Examples | LYCRASpandex stretch | LYCRA in fabricSpandex content% by weight | Open width/cylinder | Wet set temperature deg.C | Wet set time minute | Basis weight g/m2 | Maximum% elongation length x width | Percent shrinkage warp-weft | Fraction of 360 DEG of cloth cover curling degree |
| 1 | 2 | 6 | Open width | Is free of | Is free of | 219 | 112×150 | -3×-3 | 1/2 |
| 2 | 2 | 6 | Open width | 110 | 5 | 219 | 115×158 | -2×-3 | 1/2 |
| 3 | 2 | 6 | Open width | 130 | 15 | 194 | 95×155 | -3×-3 | 1/2 |
| 4 | 2 | 6 | Cylinder | Is free of | Is free of | 232 | 97×153 | -3×2 | 3/8 |
| 5 | 2 | 6 | Cylinder | 110 | 5 | 229 | 98×144 | -3×2 | 3/8 |
| 6 | 2 | 6 | Cylinder | 130 | 15 | 206 | 80×143 | -3×3 | 1/4 |
| 7 | 2 | 6 | Open width | Is free of | Is free of | 220 | 115×156 | -2×-3 | 1/2 |
| 8 | 2 | 6 | Open width | 110 | 5 | 210 | 108×156 | -2×-2 | 1/2 |
| 9 | 2 | 6 | Open width | 130 | 15 | 171 | 74×154 | -1×-1 | 3/8 |
| 10 | 2 | 6 | Cylinder | Is free of | Is free of | 229 | 98×156 | -3×2 | 1/2 |
| 11 | 2 | 6 | Cylinder | 110 | 5 | 225 | 97×149 | -2×2 | 1/2 |
| 12 | 2 | 6 | Cylinder | 130 | 15 | 173 | 57×151 | -4×4 | 1/2 |
| 13 | 2 | 7 | Open width | Is free of | Is free of | 242 | 97×123 | -3×-2 | 1/8 |
| 14 | 2 | 7 | Open width | 110 | 5 | 244 | 93×117 | -3×-2 | 0 |
| 15 | 2 | 7 | Open width | 130 | 15 | 238 | 71×95 | -2×-4 | 1/4 |
| 16 | 2 | 7 | Cylinder | Is free of | Is free of | 254 | 97×135 | -2×0 | 1/8 |
| 17 | 2 | 7 | Cylinder | 110 | 5 | 258 | 92×129 | -1×0 | 0 |
| 18 | 2 | 7 | Cylinder | 130 | 15 | 251 | 69×106 | -1×0 | 0 |
| 19 | 2 | 7 | Open width | Is free of | Is free of | 248 | 104×120 | -3×-2 | 0 |
| 20 | 2 | 7 | Open width | 110 | 5 | 244 | 98×118 | -2×-2 | 0 |
| 21 | 2 | 7 | Open width | 130 | 15 | 209 | 63×86 | -2×-1 | 1/2 |
| 22 | 2 | 7 | Cylinder | Is free of | Is free of | 260 | 103×130 | -2×0 | 1/8 |
| 23 | 2 | 7 | Cylinder | 110 | 5 | 258 | 100×129 | -2×0 | 0 |
| 24 | 2 | 7 | Cylinder | 130 | 15 | 220 | 62×102 | -2×0 | 1/8 |
| 25 | 3 | 4 | Cylinder | Is free of | Is free of | 300 | 155×169 | -2×1 | 1/4 |
| 26 | 3 | 4 | Cylinder | 130 | 15 | 189 | 88×178 | -7×-4 | 5/8 |
| 27 | 2 | 12 | Open width | Is free of | Is free of | 285 | 144×138 | -1×-1 | 1/2 |
| 28 | 2 | 12 | Open width | 130 | 15 | 220 | 101×136 | 0×-2 | 1/2 |
| 29 | 2.5 | 18 | Open width | Is free of | Is free of | 302 | 173×152 | 0×-5 | 1/2 |
| 30 | 2.5 | 18 | Open width | 130 | 15 | 293 | 163×167 | 0×-2 | 1/8 |
| 31 | 2 | 27 | Open width | Is free of | Is free of | 268 | 160×136 | 0×-2 | 7/8 |
| 32 | 2 | 27 | Open width | 130 | 15 | 267 | 153×140 | 0×-1 | 1/8 |
| 33 | 1.9 | 5 | Cylinder | 120 | 20 | 266 | 50×68 | -12×-8 | 0 |
| 34 | 1.9 | 5 | Cylinder | 130 | 20 | 229 | 37×59 | -15×-3 | 0 |
| 35 | 1.9 | 3.5 | Cylinder | 120 | 20 | 249 | 45×61 | -15×-7 | 0 |
| 36 | 1.9 | 3.5 | Cylinder | 130 | 20 | 219 | 34×66 | -12×-4 | 0 |
| 37 | 1.9 | 5 | Cylinder | 120 | 20 | 293 | 60×102 | -6×-6 | 0 |
| 38 | 1.9 | 5 | Cylinder | 130 | 20 | 261 | 57×85 | -4×-1 | 0 |
| 39 | 1.9 | 3.5 | Cylinder | 120 | 20 | 268 | 57×102 | -5×-5 | 0 |
| 40 | 1.9 | 3.5 | Cylinder | 130 | 20 | 245 | 48×93 | -3×-5 | 0 |
Examples
Examples 1-20 denier spandex had a feed tension of 1.5 grams (1.47cN), which ranged from 4 to 6 cN. The tightly twisted yarn in this example was ring spun cotton (32Ne, 165 denier). The fabric is dyed and finished according to the method 63a illustrated in fig. 5. The fabric was slit and width dried as in 63 a.
Example 2-processing line 65a according to fig. 6 (including wet-setting step 74) similar to example 1 with hot water (230) in a spray dryerOr 110 c) the knitted fabric of example 1 is treated for 5 minutes and dyed and finished. The finished fabric of example 2 had the same basis weight (weight), elongation, shrinkage and face curl as the needle fabric of example 1, even though the fabric was finished using a wet-set step. This example demonstrates that even at wet-set temperatures, wet-set is insufficient to alter the fabric properties over a 5 minute period.
Example 3-hot water (266) was used in a spray dryer analogously to example 2Or 130 ℃) the knitted fabric of example 1 was treated for 15 minutes and dyed and finished. The basis weight of the finished fabric in example 3 was 194g/m211% lower than example 1.
Example 4-the knitted fabric of example 1 was dyed and finished according to the method illustrated in figure 5. The fabric is dried in a cylindrical shape according to processing line 63 b. Since the required fabric weight of a cylindrical commodity is about 200g/m2This method produced an extra heavy fabric (232 g/m)2) Although all other fabric properties are desirable.
Example 5-processing line 65b according to fig. 6 (including cylinder wet-setting step 74) similar to example 4 with hot water (230) in a spray dryerOr 110 c) the knitted fabric of example 1 is treated for 5 minutes and dyed and finished. The basis weight of the finished fabric in example 5 was only 1% lower than the fabric in example 4. The maximum length elongation, shrinkage and face curl of example 5 were the same as the knitted fabric in example 4, although the fabric was finished using a wet-set step. This example demonstrates that even under wet-set processing conditions (elevated temperature and pressure), wet-setting is insufficient to alter the fabric properties over a 5 minute period.
Example 6-hot water (266) in a spray dryer analogously to example 5Or 130 ℃) the knitted fabric of example 1 was treated for 15 minutes and dyed and finished. The basis weight of the finished fabric in example 6 was 206g/m2Lower by 10% than example 4 and acceptable for a cylindrical T-shirt.
Example 7-processing parameters were the same as in example 1, except that a different spandex yarn LYCRA was usedSpandex Type 562B (easy to shape) was fed as Spandex. The results are comparable to the fabric in example 1.
Example 8-processing line 65a according to fig. 6 (including cylinder wet forming step 74) similar to example 1 with hot water (230) in a spray dryerOr 110 ℃ C.) the knitted fabric of example 7 was treated for 5 minutes and dyed and finished. The basis weight of the finished fabric in example 8 was only 5% lower than the fabric in example 7. The maximum length elongation, shrinkage and face curl of example 8 were similar to the knitted fabric of example 7, although the fabric was finished using a wet-set step. This example illustrates that even at wet-set temperatures, wet-set takes 5 minutesThe shape is not sufficient to alter the fabric properties.
Example 9-Hot Water (266) in a spray dryer analogously to example 1Or 130 ℃) the knitted fabric of example 7 was treated for 15 minutes and dyed and finished. The resulting knitted fabric is processed according to processing line 65a of fig. 6 to obtain a flat fabric. The spandex is higher than other LYCRA gradesSpandex brand Spandex is more sensitive to heat, with the basis weight of the fabric in example 9 being 171g/m219% lower than the fabric in example 7. Elongation, shrinkage and fabric cover crimp are acceptable for making T-shirts.
Example 10-the knitted fabric of example 7 was dyed and finished according to the method illustrated in figure 5. The fabric is dried in a cylindrical shape according to processing line 63 b. Since the required fabric weight of a cylindrical commodity is about 200g/m2This method produced an extra heavy fabric (229 g/m)2) Although all other fabric properties are desirable.
Example 11-processing line 65b according to fig. 6 (including cylinder wet-setting step 74) similar to example 4 with hot water (230) in a spray dryerOr 110 ℃ C.) the knitted fabric of example 7 was treated for 5 minutes and dyed and finished. The basis weight of the finished fabric in example 11 was only 2% lower than the fabric in example 10. The maximum length elongation, shrinkage and face curl of example 11 were the same as those of the knitted fabric of example 10, although the fabric was finished by the wet-set step. This example demonstrates that even at wet-set temperatures, wet-set is insufficient to alter the fabric properties over a 5 minute period.
Example 12-Hot Water (266) in a spray dryer analogously to example 11Or 130 ℃) the knitted fabric of example 7 was treated for 15 minutes and dyed and finished. The basis weight of the finished fabric in example 12 was 173g/m223% lower than the fabric in example 7 and acceptable for a cylinder T-shirt.
Examples 13-20 denier spandex had a feed tension of 1.70 grams (1.67 cN), which ranged from 4 to 6 cN. The tightly twisted yarn in this example was textured nylon (140 denier/48 filaments). The fabric was dyed and finished according to fig. 5. The fabric is slit and web dried as in process line 63 a.
Example 14-process line 65a according to fig. 6 (including wet-setting step 74) similar to example 13 with hot water (230) in a spray dryerOr 110 ℃ C.) the knitted fabric of example 13 was treated for 5 minutes and dyed and finished. The finished fabric of example 14 had the same basis weight (weight), elongation, shrinkage and face curl as the knitted fabric of example 13, although the fabric was finished using a wet-set step. This example demonstrates that even at wet-set temperatures, wet-set is insufficient to alter the fabric properties over a 5 minute period.
Example 15-Hot Water (266) in a spray dryer analogously to example 14Or 130 ℃) the knitted fabric of example 13 was treated for 15 minutes and dyed and finished. The warp direction elongation of the finished fabric in example 15 was significantly reduced (> 25%) compared to the finished fabric in example 13.
Example 16-the knitted fabric of example 13 was dyed and finished according to the method illustrated in figure 5. The fabric is dried in a cylindrical shape according to processing line 63 b.
Example 17-processing line 65b according to fig. 6 (including cylinder wet-setting step 74) similar to example 16 with hot water in a spray dryer(230Or 110 ℃ C.) the knitted fabric of example 13 was treated for 5 minutes and dyed and finished. The warp direction elongation of the finished fabric in example 17 was only 5% lower than that of example 16. The basis weight, shrinkage and face curl of the fabric of example 17 were substantially the same as the knitted fabric of example 16, although the fabric was finished using a wet-set step. This example demonstrates that even at wet-set temperatures, wet-set is insufficient to alter the fabric properties over a 5 minute period.
Example 18-Hot Water (266) in a spray dryer analogously to example 17Or 130 ℃) the knitted fabric of example 13 was treated for 15 minutes and dyed and finished. The warp elongation of the finished fabric in example 18 was 69%, 28% lower than example 16 and acceptable for a tubular T-shirt. The basis weight, shrinkage and face curl of the fabric were also substantially the same as in example 16.
Example 19-processing parameters were the same as in example 13, except that a different spandex yarn LYCRA was usedSpandex Type 562B (easy to shape) was fed as Spandex. The results are comparable to the fabric in example 13.
Example 20-process line 65a according to fig. 6 (including cylinder wet-setting step 74) similar to example 19 with hot water (230) in a spray dryerOr 110 ℃ C.) the knitted fabric of example 19 was treated for 5 minutes and dyed and finished. The basis weight of the finished fabric in example 20 was only 2% lower than the knitted fabric of example 19. The maximum length elongation, shrinkage and face curl of example 20 were similar to the knitted fabric of example 19, although the fabric was finished using a wet-set step. This embodimentIt is stated that even at the wet-set temperature, wet-set is not sufficient to change the fabric properties over 5 minutes.
Example 21-hot water (266) in a spray dryer analogously to example 20Or 130 ℃) the knitted fabric of example 19 was treated for 15 minutes and dyed and finished. The resulting knitted fabric is processed according to processing line 65a of fig. 6 to obtain a flat fabric. The spandex is higher than other LYCRA gradesSpandex brand Spandex is more sensitive to heat, with the basis weight of the fabric in example 21 being 209g/m214% lower than the fabric in example 19.
Example 22-dyeing and finishing the knitted fabric of example 19 according to the method illustrated in figure 5. The fabric is dried in a cylindrical shape according to processing line 63 b. This method produced extra heavy fabrics (260 g/m)2) Although all other fabric properties are desirable.
Example 23-processing line 65b according to fig. 6 (including cylinder wet-setting step 74) similar to example 22 with hot water (230) in a spray dryerOr 110 ℃ C.) the knitted fabric of example 19 was treated for 5 minutes and dyed and finished. The basis weight of the finished fabric in example 23 was only 1% lower than the fabric in example 22. The maximum length elongation, shrinkage and face curl of example 23 were the same as those of the knitted fabric in example 22, although the fabric was finished by the wet-set step. This example demonstrates that even at wet-set temperatures, wet-set is insufficient to alter the fabric properties over a 5 minute period.
Example 24-Hot Water (266) in a spray dryer analogously to example 23Or 130 ℃) the knitted fabric of example 19 was treated for 15 minutes and dyed and finished. The basis weight of the finished fabric in example 24 was 220g/m215% lower than the fabric in example 22.
Examples 25-20 denier spandex stretch was 3.0 x. The tightly twisted yarn in this example was ring spun cotton (32Ne, 165 denier). The fabric was dyed and finished according to the method illustrated in fig. 5. The fabric is dried in a cylindrical shape according to processing line 63 b.
Example 26-process line 65b according to fig. 6 (including cylinder wet-setting step 74) similar to example 25 with hot water (266) in a spray dryerOr 130 ℃) the knitted fabric of example 25 was treated for 15 minutes and dyed and finished. The basis weight of the finished fabric in example 26 was 37% lower than the fabric in example 25.
Examples 27-40 denier spandex stretch 2.0 x. The tightly twisted yarn in this example was ring spun cotton (32Ne, 165 denier). The fabric was dyed and finished according to the method illustrated in fig. 5. The fabric was slit and dried open width according to processing line 63 a.
Example 28-process line 65a according to fig. 6 (including cylinder wet-setting step 74) similar to example 27 with hot water (266) in a spray dryerOr 130 ℃) the knitted fabric of example 27 was treated for 15 minutes and dyed and finished. The basis weight of the finished fabric in example 28 was 23% lower than the fabric in example 25.
Example 29-the tightly twisted yarn in this example was a textured polypropylene (100 denier, 110 dtex, 1.39 denier per filament). The spandex is LYCRA stretched by 2.5 ×Spandex T162C (55 denier, 61 dtex). The fabric is dyed and finished according to the scheme 63a of fig. 5.
Example 30-Hot Water (266) in spray dryer 74 according to FIG. 6 route 65aOr 130 deg.C) the knit fabric of example 29 was wet-set for 15 minutes and dried.
Example 31-the tightly twisted yarn in this example was a textured polypropylene (100 denier, 110 dtex, 1.39 denier per filament). LYCRA with spandex of 2.0x stretchSpandex T162C (70 denier, 78 dtex). The fabric is dyed and finished according to the path 63a of fig. 5.
Example 32-Hot Water (266) in spray dryer 74 according to FIG. 6 route 65cOr 130 deg.C) the knit fabric of example 31 was wet-set for 15 minutes and dried.
Example 33-in this example a double back loop jersey knit was knitted with 100% cotton 30/1Ne yarn as the jersey feed and 100% cotton 20/1 Ne yarn as the loops. Feeding Gaosai with 33 dtex T562B LYCRA stretched at 1.9XSpandex plating. The fabric is wet processed (including wet heat setting at 120 c for 20 minutes) and napped to provide a single face pile finished fabric, per path 85b of fig. 7.
Example 34-the fabric of example 33 was wet processed (including wet heat setting at 130 c for 20 minutes) and napped to give a single face pile finished fabric, according to the scheme 85b of figure 7.
Example 35-in this example a double back loop jersey knit was knitted with 100% cotton 30/1Ne yarn as the jersey feed and 100% cotton 20/1 Ne yarn as the loops. Feeding Gaosai with 22dtex T562B LYCRA stretched at 1.9XSpandex plating. The fabric is wet processed (including wet heat setting at 120 c for 20 minutes) and napped to provide a single face pile finished fabric, per path 85b of fig. 7.
Example 36-the fabric of example 35 was wet processed (including wet heat setting at 130 c for 20 minutes) and napped to give a single face pile finished fabric, according to the scheme 85b of figure 7.
Example 37-in this example a double back loop jersey knit was knitted with 100% cotton 30/1Ne yarn as the jersey feed and 100% cotton 20/1 Ne yarn as the loops. Feeding Gaosai with 33 dtex T562B LYCRA stretched at 1.9XSpandex plating. The fabric is wet processed according to the route 85b of fig. 7 to obtain a finished back loop jersey.
Example 38-the fabric of example 37 was wet processed according to route 85b of figure 7 to give a finished back knit flat fabric.
Example 39-in this example a double back loop jersey knit was knitted with 100% cotton 30/1Ne yarn as the jersey feed and 100% cotton 20/1 Ne yarn as the loops. Feeding Gaosai with 22dtex T562B LYCRA stretched at 1.9XSpandex plating. The fabric is wet processed according to the route 85b of fig. 7 to obtain a finished back loop jersey.
Example 40-the fabric of example 39 was wet processed according to route 85b of figure 7 to give a finished back knit flat knit.
Thus, it should be understood that: the present invention has provided a useful circular knit elastic fabric of at least one of single jersey, jersey back, and fleece with bare elastomeric material and spun and/or filament hard-twisted plated yarn, and a method of making the same, which does not require a dry heat-setting step and fully satisfies the objects and advantages set forth above. While the invention has been described in conjunction with specific embodiments, it is evident that: many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
Claims (20)
1. A method of making a circular knit, elastic, single jersey fabric, the method comprising the steps of:
providing an elastic material;
providing at least one tight-twist yarn selected from the group consisting of spun yarns, filament yarns, and combinations thereof;
plating the elastic material with the at least one hard twist;
circularly knitting the plated elastic material and the at least one hard-twisted yarn in each course of knitting to produce a circularly knitted elastic single jersey fabric; and
the circular knitted elastic single-sided jersey fabric and the continuous phase aqueous solution are heated to 105-145 ℃ and not more than 4.0kg/cm2For 5 to 90 minutes under pressure.
2. A method of making a circular knit, elastic fabric of at least one of a back loop jersey and a pile, the method comprising the steps of:
providing an elastic material;
providing at least two tight-twisted yarns selected from the group consisting of spun yarns, filament yarns, and combinations thereof;
plating the elastic material with the at least two tight-twist yarns;
circularly knitting the plated elastic material and at least two close-twisted yarns to produce a circular knit elastic fabric of at least one of a back loop jersey and a pile, wherein the elastic material is knitted in spaced courses; and
subjecting said circular knit elastic fabric of at least one of a back loop jersey and a pile to a continuous phase aqueous solution at a temperature of 105 ℃ to 145 ℃ and not more than 4.0kg/cm2For 5 to 90 minutes under pressure.
3. The method of any of claims 1 and 2 wherein in the step of providing an elastic material, said elastic material is further defined as uncoated spandex yarn of 15 to 156 dtex.
4. The method of claim 1, wherein in the step of providing at least one tight yarn, the at least one tight yarn is further defined as a tight yarn having a yarn count Nm of from 10 to 165.
5. The method of claim 2, wherein in the step of providing at least two tight yarns, each of said at least two tight yarns is further defined as a tight yarn having a yarn count Nm of from 10 to 165.
6. The process of any of claims 1 and 2, wherein the circular knit elastic fabric has a cover factor of from 1.05 to 1.9.
7. The process of any of claims 1 and 2, further comprising the step of exposing the circular knit elastic fabric to at least one further treatment step, wherein such treatment step is carried out at a temperature below that required to heat-set the elastic material.
8. The method of claim 7, wherein in said at least one further processing step, said circular knit elastic fabric is exposed to a temperature of less than 160 ℃.
9. The method of claim 7, wherein the at least one further processing step is selected from the group consisting of cleaning, bleaching, dyeing, drying, preshrinking, and any combination thereof.
10. The method of claim 9, wherein said at least one further processing step is selected from the group consisting of drying, preshrinking, and combinations thereof, and wherein said circular knit elastic fabric has overfeeding along its length during said at least one further processing step.
11. The method of any of claims 1 and 2, wherein the circular knit elastic fabric has an elastic material content of from 3.5% to 30% by weight, based on the total weight of the fabric per square meter.
12. The method of any of claims 1 and 2, wherein the at least one hard yarn is selected from the group consisting of synthetic filaments, staple yarns of natural fibers, natural fibers blended with synthetic fibers or yarns, staple yarns of cotton, cotton blended with synthetic fibers or yarns, polypropylene, polyethylene, or polyester staple yarns blended with polypropylene, polyethylene, or polyester fibers or yarns, and combinations thereof.
13. The method of claim 12, wherein the at least one yarn is a heat sensitive yarn.
14. The process of any of claims 1 and 2 wherein the at least one tightly-twisted yarn is selected from the group consisting of cotton yarn and cotton blended yarn, and the basis weight of said circular knit elastic fabric is 100-500g/m2。
15. The method of claim 1, wherein the circular knit, elastic, single face jersey fabric has an elongation in the warp direction of at least 60% and a post-wash shrinkage of 14% or less.
16. The method of claim 1, wherein said circular knit, elastic, single-face jersey fabric is prepared in a cylindrical shape and wherein substantially no visible side creases are formed.
17. The method of claim 2, wherein the at least two tightly twisted yarns are the same.
18. The method of claim 2, wherein the at least two tightly twisted yarns are different.
19. The method of claim 2, wherein the circular knit elastic fabric has an elongation in the warp direction of at least 35% and a post-wash shrinkage of 15% or less.
20. The method of any of claims 1 and 2, wherein in the circular knitting step, the feeding of the elastic material is controlled so that the elastic material stretches no more than 7 x of its original length when knitting to produce the circular knitted elastic fabric.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US66836005P | 2005-04-04 | 2005-04-04 | |
| US60/668,360 | 2005-04-04 | ||
| US11/203,078 US7634924B2 (en) | 2004-06-01 | 2005-08-12 | Knit by design method and fabric |
| US11/203,078 | 2005-08-12 | ||
| PCT/US2006/012249 WO2006107844A1 (en) | 2005-04-04 | 2006-03-31 | Method to make circular knit elastic fabric comprising spandex and hard yarns |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK1123583A1 HK1123583A1 (en) | 2009-06-19 |
| HK1123583B true HK1123583B (en) | 2014-08-29 |
Family
ID=
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI841522B (en) | Stretch knit fabrics containing elastomeric fiber and polyester bi-component filament | |
| CN100554547C (en) | Method for producing circular knitted fabric, single-sided knitted fabric, circular knitted fabric, elastic single-sided knitted fabric, and garment | |
| US9689091B2 (en) | Stretch circular knit fabrics with multiple elastic yarns | |
| KR101256249B1 (en) | Method to Make Circular Knit Elastic Fabric Comprising Spandex and Hard Yarns | |
| CN101084332B (en) | Circular knit elastic fabric and its making method | |
| CN101223307B (en) | Method of making circular knit elastic fabric comprising spandex and tight twist yarn | |
| US7797968B2 (en) | Method to make circular knit elastic fabric comprising spandex and hard yarns | |
| HK1123583B (en) | Method to make circular knit elastic fabric comprising spandex and hard yarns | |
| KR20250151715A (en) | A stretch knit fabric containing elastomeric fibers and polyester bicomponent filaments, and a garment made therefrom, and a method of making the same. garments made therefrom, and methods of making the same | |
| HK1120838A (en) | Circular knitting of elastic fabrics containing an elastomeric yarn | |
| HK1188471A (en) | Circular knitting of elastic fabrics containing an elastomeric yarn | |
| HK1113594B (en) | Method for making a circular-knit elastic fabric and corresponding fabric |