JP7797572B2 - Snag-resistant knitted fabric - Google Patents

Description

The present invention relates to a knitted fabric that has stretchability and snag resistance and is suitable for use in clothing such as work uniforms.

Knitted fabrics have superior characteristics compared to woven fabrics, such as a softer texture and greater stretchability, and are therefore widely used in innerwear and sportswear. However, compared to woven fabrics, knitted fabrics tend to have lower pilling, snag resistance, and abrasion resistance, making them difficult to use as a material for work uniforms, etc.

For this reason, various studies have been conducted to improve the snag resistance of knitted fabrics. For example, a method of twisting the yarns that make up the knitted fabric has been proposed in order to increase the binding force of the yarns that appear on the surface of the knitted fabric (see Patent Document 1). However, the knitted fabric obtained using this method has the problem of losing the soft texture and stretchability that are inherently characteristic of knitted fabrics.

Another proposed approach involves anti-snag knitting using a low-torque composite yarn obtained by entangling a doubling of a false-twisted yarn with S-direction torque and a false-twisted yarn with Z-direction torque (see Patent Document 2). While this method can produce knitting with sufficient anti-snag properties, it requires producing separate false-twisted yarns in the S and Z directions and then entangling the doubling, resulting in a complex and cumbersome manufacturing process and being economically disadvantageous.

Furthermore, as a knitted fabric that has stretchability and snag resistance, as well as excellent firmness and a soft feel, a knitted fabric containing a composite false-twisted yarn consisting of a yarn containing conjugated false-twisted yarn A and non-conjugated false-twisted yarn B has been proposed, in which the number of entanglements of the composite false-twisted yarn is 100 or more/m, the torque twist number is 30 T/m or less, and the difference in crimp occurrence rate is 5 to 30% (see Patent Document 3). However, this method requires a process of using both conjugated false-twisted yarn and non-conjugated false-twisted yarn and strongly entangling them, which makes the manufacturing process complicated and cumbersome, making it economically disadvantageous.

Japanese Patent Application Laid-Open No. 2003-247149 WO2008/001920 publication Japanese Patent Application Laid-Open No. 2022-166393

The present invention was devised to solve the problems of the prior art described above, and its purpose is to provide a knitted fabric that combines the snag resistance and stretchability required for use in uniforms and other applications. Furthermore, the present invention aims to provide a knitted fabric that is ideal for uniform use, in which even when colored antistatic yarns are blended, the antistatic yarns are not easily visible through the surface.

Conventionally, in knitted fabrics consisting of knits, tucks, and welts, the frequent use of tucks significantly changes the size of the knit loops within the knitted fabric, resulting in greater unevenness on the knitted fabric surface, making it more susceptible to snagging and resulting in snagging. However, after extensive research, the inventors discovered that by using a specific false-twisted yarn with a high stretch elongation rate to impart a knit-tuck basic unit structure to the knitted fabric surface, it is possible to achieve stretchability while also exhibiting previously unimaginable high levels of snag resistance, leading to the completion of this invention.

That is, the present invention has the following configurations (1) to (4).
(1) A knitted fabric comprising a single knit having knit-tuck unit structures on at least one surface thereof, wherein at least a portion of the knit-tuck unit structures is made of false-twisted yarn having a stretch elongation rate of 40 to 95%, and the ratio of knit-tuck unit structures made of false-twisted yarn having a stretch elongation rate of 40 to 95% to the entire structure constituting said one surface is 25 % or more and less than 100%, and wherein at least one surface contains both knit-tuck unit structures and all-knit unit structures.
(2) The knitted fabric according to (1), wherein the false twist yarn having a stretch elongation rate of 40 to 95% is made of conjugate composite fiber.
(3) A knitted fabric as described in (1), characterized in that the course density on one side is 50 (pieces/2.54 cm) or more and 95 (pieces/2.54 cm) or less, and the wale density is 45 (pieces/2.54 cm) or more and 80 (pieces/2.54 cm) or less.
(4) The knitted fabric according to (2), characterized in that the conjugate composite fiber is made of polybutylene terephthalate and polyethylene terephthalate, and the knit-tuck unit structure composed of the false twist yarn of the conjugate composite fiber constitutes 40 to 100% of the structure constituting one side.

The present invention provides a knitted fabric that combines stretchability and snag resistance, making it suitable for clothing such as working uniforms. Furthermore, even when colored antistatic yarns are used in the knitted fabric of the present invention, the antistatic yarns are less likely to be visible through the surface.

FIG. 1 is a stitch configuration diagram consisting of only knit-tuck unit structures. 2(a) and (b) are knitting structure diagrams for explaining the knit-tuck unit structure and how to count the numbers of knit loops, tuck loops, and welts. FIG. 3 is a knitting structure diagram of the knitted fabric of Example 1. FIG. 4 is a knitting structure diagram of the knitted fabric of Example 3. FIG. 5 is a knitting structure diagram of the knitted fabric of Example 5. FIG. 6 is a knitting structure diagram of the knitted fabric of Comparative Example 3.

The knitted fabric of the present invention is knitted on a knitting machine with a single or double needle bed. Since double knits knitted on a double knitting machine can have either the front or back side used as the front side of the product, for convenience in this invention these will be referred to as one side and the other side, and the side expected to be used as the front side of the final product will be referred to as one side.

The knitted fabric of the present invention is characterized by having a knit-tuck unit structure (hereinafter also referred to as a "basic knit-tuck structure" or "knit-tuck repeat structure") on at least one side of the knitted fabric, which is composed of a false-twisted yarn with a stretch elongation rate of 40 to 95% (hereinafter also referred to as a highly stretchable false-twisted yarn). An example of a knit-tuck unit structure is shown in Figure 1. Figure 1 is a stitch configuration diagram consisting only of a knit-tuck unit structure. When one side of the knitted fabric comes into contact with something, the upper side of the knit loop becomes a convex part on the knitted fabric surface, making it prone to getting caught there. However, in a knit-tuck unit structure, the area where the tuck yarn of the previous course and the apex of the knit loop meet (the area indicated by the arrow in Figure 1), overlaps with the tuck of the previous course, the apex of the knit loop, and the sinker loop of the next course, forming a convex part on the knitted fabric surface. If the knit loops are sufficiently small, the yarns will bind each other, making it difficult for the fibers to be pulled out. Specifically, in the present invention, by using a highly stretchable and elongated false-twisted yarn to form the knit-tuck unit structure on one side, the highly stretchable and elongated false-twisted yarn shrinks significantly during processing, developing crimp, reducing the size of the knit loops and making them very tight, making it difficult for the fibers to be pulled out. This is thought to improve snag resistance in the present invention. In other words, false-twisted yarns with a high stretch and elongation rate develop very high crimp, but the apparent upper yarn shrinks significantly due to the development of crimp, causing the knit fabric to shrink and the knit loops to become smaller. Furthermore, the yarn becomes bulky during dyeing, increasing the apparent thickness of the yarn and reducing the gaps within the knit loops. It is thought that the smaller knit loops tighten the knit fabric, improving snag resistance and also improving see-through resistance.

When the knitted fabric is single knit, there is a single layer of knit loops, but there is a front and back, called the sinker loop side and the knit loop side, and on both sides the overlapping parts become the convex parts of the uneven knitted surface. Incidentally, when the knitted fabric is double knit, both the back and front sides are knit loop sides.

The stretch extension percentage of the highly stretchable false-twisted yarn used in the present invention is 40 to 95%, preferably 50 to 95%, and more preferably 60 to 95%. If the stretch extension percentage is below this range, it will be difficult to achieve both stretchability and snag resistance in the knitted fabric. If it exceeds this range, although sufficient stretchability will be achieved, the quality and physical properties of the false-twisted yarn will tend to become unstable, which will result in greater variation in the density and basis weight of the knitted fabric and make it difficult to stabilize the quality of appearance, etc. By controlling the stretch extension percentage within the above range, it is possible to impart to the knitted fabric appropriate stretchability, snag resistance, and even see-through resistance.

In the present invention, the hot water dimensional change rate of the highly stretchable false-twisted yarn is preferably -15.0% to -4.5%, and more preferably -12.0% to -5.0%. If the hot water dimensional change rate is lower than the above range, it is difficult to shorten the loop length of the knitted fabric by hot water treatment during processing, and it is difficult to form a dense structure on one side. As a result, it becomes difficult to obtain sufficient snag resistance. If the hot water dimensional change rate exceeds the above range, there is likely to be greater variation in the knitted fabric properties and appearance, making it difficult to obtain stable quality. Note that the - (minus) sign in the hot water dimensional change rate indicates the shrinkage of the sample, and the larger the - (minus) sign, the higher the shrinkage rate.

In the present invention, the highly stretchable false-twisted yarn is preferably a conjugate composite fiber. A conjugate composite fiber is a single fiber formed by bonding two or more types of resins together. Examples of composite fibers include composite fibers with a side-by-side structure or a core-sheath structure containing both polybutylene terephthalate and polyethylene terephthalate, or polytriethylene terephthalate and polyethylene terephthalate. The composite fiber preferably contains a total of 90% by mass or more of polybutylene terephthalate (or polytriethylene terephthalate) and polyethylene terephthalate, more preferably 95% by mass or more, and even more preferably 99% by mass or more. Furthermore, the composite fiber preferably contains 40 parts by mass or more and 200 parts by mass or less of polybutylene terephthalate (or polytriethylene terephthalate) per 100 parts by mass of polyethylene terephthalate, more preferably 70 parts by mass or more and 150 parts by mass or less, and even more preferably 90 parts by mass or more and 110 parts by mass or less. In the case of a core-sheath structure, it is desirable for the core to be eccentrically positioned within the sheath in order to produce crimp. The cross-sectional shape of the fiber can be round, elliptical, triangular, square, or other polygonal cross-sections, or hollow. Of these, round and elliptical cross-sections are preferred, with round being more preferred. Composite fibers may contain various additives to the extent that the above-mentioned crimp properties can be utilized.

In the present invention, the total fineness of the highly stretchable, elongated false-twisted yarn is preferably 30 dtex to 250 dtex, more preferably 50 dtex to 180 dtex. If the total fineness is below this range, the knitted fabric will be too thin and difficult to use; if it exceeds this range, the knitted fabric will be too heavy and thick and difficult to use. The single yarn fineness of the highly stretchable, elongated false-twisted yarn is preferably in the range of 0.3 dtex to 3.0 dtex. If the single yarn fineness is below this range, the fabric will be prone to snagging and its anti-snag properties will decrease; if it exceeds this range, the fabric will tend to have a stiff texture. The highly stretchable, elongated false-twisted yarn may also contain additives such as inorganic particles such as titanium particles, ultraviolet absorbers, conductive agents, heat storage agents, thermal stabilizers, antibacterial agents, lubricants, pigments, and dyes.

The false twisting device used to produce the highly stretchable, elongated false-twisted yarn of the present invention is not particularly limited, and any conventionally known device may be used, such as a multi-axis circumscribing type, an inscribing type, a pin type, or a belt type. The pin type is particularly preferred because it is more likely to achieve high stretchability and extensibility. Furthermore, a draw false-twisting machine generally has two heating zones: a first heater installed in the twisting zone, and a second heater installed downstream of the false-twisting device. Both heaters use a heat medium or electric heating method. The second heater is not necessarily required to produce the highly stretchable, elongated false-twisted yarn of the present invention, but if one is used, it is desirable to set the second heater temperature to a low temperature between room temperature and the glass transition temperature. Since the yarn is generally heat-treated by overfeeding, it is preferable to use a non-contact hollow pipe heater as the second heater.

In the first heater, the yarn is twisted and heat-set while being drawn, so the yarn temperature is treated at a range above the glass transition temperature and below the melting point, specifically in the range of 80 to 220°C, more preferably 160 to 210°C, and even more preferably 180 to 210°C. The first heater may be either a non-contact or contact type, but a non-contact type is preferred from the perspective of machine maintenance. Needless to say, the values given above as the appropriate temperature range refer to the yarn temperature and are different from the heater setting temperature.

The false twisting device is not particularly limited as described above, and the false twisting operation speed also varies depending on the device. For example, pin-type devices typically operate at speeds of around 80 to 150 m/min, belt-type devices at around 350 to 800 m/min, and friction disk devices at around 400 to 1000 m/min. The speed can be selected appropriately depending on the type of draw-texturing machine. The false-twisted yarn is then wound onto a paper tube by a winder, and either a straight wind or a biconical wind package shape can be used. When winding onto the paper tube, it is preferable to attach a tail (tail yarn) in order to ensure continuous operation from the next process onwards.

The blend ratio of high-stretch, elongated false-twisted yarn in the weave constituting one side of the knitted fabric of the present invention is preferably 40% by mass or more. More preferably, it is 50% by mass or more, even more preferably 70% by mass or more, and particularly preferably 100% by mass. When high-stretch, elongated false-twisted yarn is present in a blend ratio equal to or greater than the above, the knit loops appear smaller and there are fewer gaps, which tends to improve snag resistance. On the other hand, when the blend ratio is less than the above, the tightness of the knit loops and tucks tends to weaken, which tends to reduce snag resistance. Furthermore, when high-stretch, elongated false-twisted yarn is incorporated to form the weave on both sides of a double knit, the weight of the high-stretch, elongated false-twisted yarn constituting one side can be calculated for convenience by multiplying the weight of the continuous high-stretch, elongated false-twisted yarn sufficient to constitute 100W of one side by the ratio of the number of knit loops on one side to the number of knit loops constituting the other side.

The knitted fabric of the present invention may contain other yarns in addition to the highly stretchable, extensible false-twisted yarn described above, as long as the objective is achieved. Examples of other yarns include synthetic fibers such as polyester fibers, polyamide fibers such as nylon 6 and nylon 66, acrylic fibers, acrylate fibers, and olefin fibers such as polypropylene, biodegradable fibers such as polylactic acid fibers, regenerated fibers such as rayon and lyocell, and well-known natural fibers such as cotton, linen, and wool. Examples of other yarn forms include filament yarns and spun yarns, with filament yarns being preferred and multifilament yarns being more preferred. Examples of filament yarns include processed yarns such as flat yarns (raw silk), false-twisted yarns, and air-entangled yarns, but false-twisted yarns are preferred in order to prevent a decrease in the snag resistance of the knitted fabric of the present invention.

The knitted fabric of the present invention is suitable for use in uniforms for working and other applications. Antistatic yarns can be used to fulfill the antistatic properties often required for working applications. Antistatic yarns are often gray or other colors, making them highly visible, so it is preferable to design them so that they are not visible from the surface of the knitted fabric. In the case of single knits, antistatic yarns can be used in the core yarn of a core-sheath composite yarn, or the antistatic yarn can be placed on the back side of the knitted fabric by plating knitting. In the case of double knits, antistatic yarns can be used in the weave that constitutes the other side of the knitted fabric. Specifically, the antistatic yarn can be aligned and inserted into part of the weave when knitting the back side, or it can be knitted after being combined with the yarn that constitutes the weave. Placing antistatic yarns in a part of the back weave and in a part of the connection with the front weave is preferable, as it enhances the antistatic properties of the surface. In the present invention, it is preferable to connect the knit tuck portion on the surface to the front weave by tucks using a connecting yarn containing antistatic yarn. In the knit tuck structure of the present invention, the tuck yarn that makes up the front structure is combined with the knit loops, making it appear thicker, which has the advantage of making it easier to hide the antistatic yarn even when connecting tucks are added.

Furthermore, in order to impart sufficient antistatic performance to the knitted fabric of the present invention, it is preferable that the yarns containing antistatic yarns are arranged at a density of one yarn per inch or more in the wale direction. That is, it is preferable that the antistatic yarns are knitted at intervals of one inch or less in the warp direction. The antistatic yarns are preferably those in which conductive fine particles are kneaded into the fibers. Specifically, they may be conductive fibers (single-component systems) formed from a fiber-forming resin such as polyester resin or polyamide resin (conductive resin) in which a conductive material is kneaded into the fiber-forming resin, or conductive fibers (composite-component systems) formed from a conductive resin and a non-conductive resin. Examples of conductive materials include conductive carbon black; elemental metals such as silver, nickel, copper, iron, and tin; and metal compounds such as copper sulfide, zinc sulfide, and copper iodide. In order to achieve excellent antistatic performance both initially and after washing, the electrical resistance of the antistatic yarn is preferably 10 ² to 10 ⁹ Ω/cm. Examples of antistatic yarns include "Clacarbo" manufactured by Kuraray Trading Co., Ltd., "Beltron" manufactured by KB Seiren Co., Ltd., "Luana" manufactured by Toray Industries, Inc., and "Emina White" manufactured by Toyobo Co., Ltd.

Next, the structure of the knitted fabric of the present invention will be described in detail, including an explanation of the knit tuck unit structure. First, with reference to Figure 2(a), we will explain how to calculate the ratio of knit tuck unit structures to the total structure of the entire knit fabric structure. The structure of Figure 2(a) is a structure in which the knitting yarn forms loops on both the front and back sides, with (1), (2), (3), (5), and (6) being knit loops, (4) being a welt, and (7) being a tuck. In other words, the structure of Figure 2(a) has five knit loops, one welt, and one tuck, for a total of seven loops, welts, and tucks.

Note that needles that are in the process of moving from the cylinder needle to the dial needle or from the dial needle to the cylinder needle on the knitting machine are not counted as welts. For example, (8) in Figure 2(a) is the yarn moving from the cylinder to the dial, and (9) is the yarn moving from the dial to the cylinder, so they are not counted as welts. Also, referring to Figure 5, there are tucks in the structure of yarn feeders F1 and F4, but these tucks connect the structure of one side to the structure of the other side and do not constitute the structure of the surface, so such tucks are not counted as part of the structure that makes up the surface.

In the present invention, the proportion of knit tuck unit structures on one side of a knitted fabric can be calculated as a percentage by dividing the number of knit tuck unit structures present in the structure on one side of the knitted fabric by the total number of knit loops, welts, and tucks present in the structure on that side. In this case, each knit tuck unit structure is counted as two (one knit and one tuck). For example, the knit structure shown in Figure 2(a) includes a pair of knit tuck structures (6) and (7), so the number is counted as two. Therefore, if we assume that the cylinder side of the structure in Figure 2(a) is one side, the proportion of knit tuck unit structures on the cylinder surface, considering only yarn feeder b, is 2/3, resulting in a composition ratio of approximately 66.7%. Furthermore, the knit structure shown in Figure 2(b) has two pairs of knit tuck basic structures, which are calculated as four in total, consisting of two knit loops and two tucks. Therefore, the proportion of knit tuck unit structures is 4/4, resulting in a composition ratio of 100%.

The knitted fabric of the present invention has knit-tuck unit structures made from highly stretchable, elongated false-twisted yarn on at least one surface, and the ratio of knit-tuck unit structures made from highly stretchable, elongated false-twisted yarn to the entire structure making up that one surface must be 25 to 100%. As described above, a knit-tuck unit structure is a knitting structure in which knit loops and tucks are connected, with knits and tucks overlapping between adjacent yarns in the course direction. The presence of many such structures at uniform intervals on the knitted surface contributes to the improved snag resistance of the present invention. The ratio of knit-tuck unit structures made from highly stretchable, elongated false-twisted yarn on one surface is preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, even more preferably 60% or more, and particularly preferably 100%. If the ratio of knit-tuck unit structures made from highly stretchable, elongated false-twisted yarn on one surface is less than the above range, there will be fewer tight knit portions that form convex portions on the knitted surface, making it more susceptible to snagging and reducing snag resistance.

As mentioned above, it is preferable that the knit-tuck unit structure exists on one side as a repeat of knit and tuck in the course direction, which corresponds to the longitudinal direction of the knitted fabric. With this structure, all knit loops are tucked, which increases the number of tight knit loops. In the structure that makes up one side, the knit-tuck unit structure preferably accounts for a constituent ratio of 40% or more. More preferably, it is 45 to 100%. If the constituent ratio is less than the above range, the repeating knit-tuck structure will be fewer, which will likely reduce the effectiveness of improving snag resistance.

The knit-tuck unit structures in the weave constituting one side of the knitted fabric of the present invention may include those composed of yarns other than the highly stretchable, elongated false-twisted yarn. However, it is preferable that the proportion of knit-tuck unit structures composed of the highly stretchable, elongated false-twisted yarn in the aggregate of knit-tuck unit structures be 40% or more. More preferably, it is 50% or more, even more preferably 60% or more, even more preferably 70% or more, and particularly preferably 100%. As described above, the highly stretchable, elongated false-twisted yarn shrinks significantly during processing and develops crimp. This makes the knit loops appear smaller, reducing gaps and improving snag resistance. Furthermore, if the content of the highly stretchable, elongated false-twisted yarn in one side is high, sufficient snag resistance is likely to be obtained even if the proportion of knit-tuck unit structures composed of the highly stretchable, elongated false-twisted yarn is 60% or less.

The course density on one side of the knitted fabric of the present invention is preferably 50 (pieces/2.54 cm) or more and 95 (pieces/2.54 cm) or less. It is more preferably 55 (pieces/2.54 cm) or more, and even more preferably 60 (pieces/2.54 cm) or more. It is also more preferably 90 (pieces/2.54 cm) or less, and even more preferably 85 (pieces/2.54 cm) or less. If the course density is below the above range, it may be difficult to improve snag resistance. On the other hand, if the course density exceeds the above range, it may be difficult to improve the texture and stretchability may not be maintained.

The wale density on one side of the knitted fabric of the present invention is preferably 45 (units/2.54 cm) or more and 80 (units/2.54 cm) or less. It is more preferably 48 (units/2.54 cm) or more, and even more preferably 50 (units/2.54 cm) or more. It is also more preferably 75 (units/2.54 cm) or less, and even more preferably 70 (units/2.54 cm) or less. If the wale density is below the above range, it may be difficult to improve snag resistance. On the other hand, if the wale density exceeds the above range, it may be difficult to improve the texture and stretchability may not be maintained.

The knitting machine used to manufacture the knitted fabric of the present invention is preferably a single or double knit knitting machine with a needle density (gauge) on the needle bed of 30 or more per inch (2.54 cm). The knitting machine gauge is preferably 30 to 50 needles/2.54 cm. If the knitting machine gauge exceeds 50 needles/2.54 cm, stretchability tends to decrease, making it necessary to use thinner yarns and reducing the strength of the knitted fabric. On the other hand, if the knitting machine gauge is less than 30 needles/2.54 cm, the density is too low and snag resistance tends to decrease.

The yarn length of the yarn forming the knit-tuck of the knitted fabric of the present invention is preferably 80 mm/100 W or more and 300 mm/100 W or less. If the yarn length is less than 80 mm/100 W, stable production may be difficult and knitting defects may not be reduced. On the other hand, if it exceeds 300 mm/100 W, it may not be possible to control the size of the knit loop and prevent a decrease in snag resistance. When multiple types of yarn are used to form the knit-tuck, the arithmetic average of the yarn lengths of the multiple structures and yarn types is considered to be the yarn length.

In addition, in the present invention, it is also a preferred embodiment that the yarn used to knit the front and/or back courses of the yarn used to knit the knit tuck be structured as an all-knit unit. Combining knit-tuck and all-knit in the wale direction before and after the knitting order makes it easier to make the knitted fabric denser. As the knitting density increases, stretchability tends to decrease, but it is more likely to contribute to snag resistance. The yarn length of the yarn forming the all-knit is preferably 120 mm/100 W or more and 350 mm/100 W or less. If the yarn length is less than 120 mm/100 W, stable production is difficult and knitting defects may not be reduced. On the other hand, if the yarn length exceeds 350 mm/100 W, it becomes difficult to prevent a decrease in snag resistance of the knitted fabric. If multiple types or strands of other yarns are used, the arithmetic average value of the other yarns is used as the yarn length of the other yarns. In addition, when multiple types of highly stretchable, stretch-twisted yarns or other yarns are used, the yarn length is measured for each feeder, and the arithmetic average of the yarn lengths of yarns with the same unit structure is used.

The yarns that make up the above knit-tuck and all-knit structures are preferably composed solely of highly stretchable, elongated false-twisted yarns, but they do not necessarily have to be composed solely of highly stretchable, elongated false-twisted yarns; other yarns may also be used as part of the yarns that make up the knit-tuck and all-knit structures.

The knitted fabric of the present invention preferably has a basis weight of 100 g/ ^m2 or more and 250 g/ ^m2 or less. More preferably, it is 120 g/ ^m2 or more. Also, more preferably, it is 220 g/ ^m2 or less. If the basis weight is less than the above range, it is not possible to improve the density of the knitted fabric, and it may not be possible to improve the firmness and stiffness and reduce the occurrence of runs. On the other hand, if the basis weight exceeds the above range, it may not be possible to improve productivity. The basis weight can be measured by the method described in the Examples below.

The weft elongation percentage of the knitted fabric of the present invention is preferably 25% or more and 100% or less. It is more preferably 85% or less, and even more preferably 70% or less. If the weft elongation percentage exceeds this range, run-out may occur more easily, making it difficult to prevent a decrease in snag resistance. On the other hand, if the weft elongation percentage is less than this range, it is difficult to say that the knitted fabric has high stretchability.

Sewn products tend to have better core quality when the elongation rate in the warp direction is kept slightly lower than that in the weft direction. Therefore, the warp elongation rate of the knitted fabric of the present invention is preferably 20% or more and 80% or less. It is more preferably 70% or less, and even more preferably 50% or less. If the warp elongation rate exceeds the above range, sewing may become difficult. On the other hand, if the warp elongation rate is less than the above range, the product may be less comfortable to wear. The above elongation rates in the warp and weft directions can be measured using the method described in the examples below.

In order to keep the elongation rate of the knitted fabric as low as described above, it is preferable to fully express the crimp of the false-twisted yarn during dyeing processing, entangle the knitted loops made of the bulky yarn, and then heat-set the knitted fabric with a stronger heat treatment. This heat-setting is preferably carried out at 180°C or higher in dry heat or 120°C or higher in wet heat, and more preferably at 190-210°C in dry heat or 125-135°C in wet heat. Specifically, the grey fabric can be subjected to a continuous relaxation process using a relaxer or similar to increase the crimp, and then subjected to a stronger heat-setting. Furthermore, in order to reduce the elongation rate of the knitted fabric in the weft direction and adjust the balance of the elongation rates in the warp and weft directions, it is also preferable to finish the knitted fabric with a slightly longer weft length by tensioning it slightly more in the weft direction than in the warp direction.

The knitted fabric of the present invention can satisfy the snag resistance performance of grade 4 or higher, and even grade 4.5 or higher, according to the D-1 method (damage bar method) of JIS-L1058.

When the knitted fabric of the present invention is double knit, it has the structure described above, which makes it easy for the connecting yarn to be hidden from one side. Even if a colored antistatic yarn is used as the connecting yarn, the presence of the antistatic yarn on the surface (one side) can be made inconspicuous. For this reason, the knitted fabric of the present invention is suitable for use in antistatic workwear such as working uniforms.

The knitted fabric of the present invention combines stretchability and snag resistance, making it suitable for outerwear such as work shirts, pants, and jackets. It is particularly suitable as a knitted fabric for uniforms, such as work uniforms, that allow for comfortable movement.

The following examples concretely demonstrate the effects of the present invention, but the present invention is not limited to the following examples and can be implemented with appropriate modifications within the scope of the spirit of the present invention.

<Total yarn size, number of filaments, single yarn size>
The total fineness of the yarn was measured based on the fineness (total fineness) A method of JIS-L1013:2010 8.3 and converted into decitex (dtex). In addition, the number of filaments was measured based on JIS-L1013:2010 8.4, and the single yarn fineness was calculated by dividing the total fineness by the number of filaments.

<Stretching and elongation rate of thread (%)>
Measured based on JIS-L1013:2010 8.11 Stretchability Method C. As a pretreatment, the skein was wrapped in gauze and treated with hot water at 90°C for 20 minutes.

<Dimensional change rate of thread in hot water>
Measurement was performed based on JIS-L1013:2010 8.18.1 Hot water dimensional change rate (method A). The treatment conditions were 100°C x 30 minutes.

<Average yarn length for knitting>
The stitch length was measured based on JIS-L1096:2010 8.8 Stitch Length. Specifically, for each type of yarn constituting the knitted structure, the measurement section was set to 100 stitches (100 wales), and the average yarn length of each yarn was calculated by dividing the length of the yarn when the initial load was applied after unraveling the yarn in the measurement section by 100. However, in the case of filament yarn, the initial load specified in JIS-L1013 5.1 (Initial Load) was used, and in the case of spun yarn, the initial load specified in JIS-L1095:6.1 (Initial Load) was used.

<Elongation rate of knitted fabric (%)>
Measurement was performed based on JIS-L1096:2010 8.16 B method (constant load), with a load of 490 cN.

<Count of knitted fabric>
The weight per unit area of the knitted fabric was measured based on the mass per unit area under standard conditions according to JIS-L1096:2010 8.3.2 A method.

<Knit density>
Based on the density of the knitted fabric in accordance with JIS-L1096:2010 8.6.2, the number of courses (number/2.54 cm) and the number of wales (number/2.54 cm) on one side of the knitted fabric were measured. The number of wales and the number of courses refer to the number of wales per inch in the horizontal direction and the number of courses per inch in the vertical direction of the knitted fabric.

<Snag resistance>
The snag rating of the outer surface of the knitted fabric was determined based on the D-1 method of JIS-L1058:2011 7.3.

<Antistatic yarn is less noticeable>
A finished knitted product (sax color) with antistatic yarn on the back was cut into a 15 cm square, which was attached to the center of a white mount, and the mount was placed up against the observation plate of an observation device for determining wrinkles after washing in JIS-L1096 8.24, and the inconspicuousness of the antistatic yarn was judged at a distance of 122 cm from the observation plate. Evaluation was made on a four-level scale: almost inconspicuous ◎, faintly visible ○, visible △, and noticeable ×.

<Frictional charging voltage>
The fabric was washed 10 times according to the JIS-L1096-C4M method and then dried, and the frictional electrification voltage was measured according to JIS-L1094:2014 7.2B method (frictional electrification voltage measurement method). However, the friction surface was the technical back (front reed side).

Example 1
A 30-inch, 36-gauge single circular knitting machine (JS type manufactured by Fukuhara Seiki Seisakusho) was used to knit a greige knit consisting of a repetition of the complete designs F1 and F2 shown in Figure 3. A pin-twisted yarn of 84 dtex (T), 48 filaments (f) circular cross-section fiber consisting of a side-by-side cross-section conjugate fiber of polybutylene terephthalate (50% by mass) and polyethylene terephthalate (50% by mass) was used as a highly stretchable false-twisted yarn for all yarn feeders. The stretch elongation of this highly stretchable false-twisted yarn was 91.6%, the dimensional change in hot water was -7.8%, and the yarn length at each yarn feeder was 175 mm/100 wales (W).

The finished grey fabric was opened and continuously scoured according to the following recipe 1, and then dyed according to the following recipe 2, followed by finishing.
Formulation 1 (scouring formulation): An open soaper type continuous scouring machine was used, with 1 g/l of Nonisole N manufactured by Satoda Kako Co., Ltd., 0.5 g/l of Neocrystal CG1000 manufactured by Nicca Chemical Co., Ltd., and 0.5 g/l of soda ash, and the bath temperature of the cleaning tank was changed from 60°C to 80°C to 80°C.

Recipe 2 (dyeing recipe): Using a Hisaka Seisakusho NS-type liquid jet dyeing machine, the fabric was dyed in a saxophone color at 130°C under high pressure at a bath ratio of 1:15, 130°C for 45 minutes using 0.2 g/L acetic acid, pH = 4, 0.5 g/L Disper N700 from Meisei Chemical Industry Co., Ltd., 0.5 g/L Neocrystal GC1000 from Nicca Chemical Co., Ltd., 1.5% owf SR1800 from Takamatsu Oil & Fat Co., Ltd., and 0.3% owf disperse dye (C.I. Disperse Blue 56). The fabric was then washed, centrifuged, and dried at 120°C in the usual manner.

Next, 1% ows (on the weight of solution) of Sunstat ES-11, an antistatic agent manufactured by Sanyo Chemical Industries, Ltd., was applied as a finishing agent. The pick-up of the finishing agent was 70%. The final setting was then performed using a pin tenter at 170°C for 120 seconds to adjust the strength and obtain the final knitted fabric. The finishing was performed without widening the fabric as much as possible, and without pulling it in the warp direction, so that wrinkles could be removed. The structure of the knitted fabric in Example 1 and the evaluation results are shown in Table 1.

Example 2
The same single circular knitting machine as in Example 1 was used to knit the same knitting structure as in Figure 3. At this time, yarn feeder F1 was knitted at a yarn length of 175 mm/100 W using the same high-stretch, elongated false-twisted yarn as in Example 1, and yarn feeder F2 was knitted at a yarn length of 175 mm/100 W using a false-twisted yarn (stretch elongation 31.3%, hot water dimensional change rate -4.1%) (hereinafter referred to as friction false-twisted yarn) with a semi-dull circular cross section that had been false-twisted using a friction false-twisting machine. The finished greige knit was dyed and finished in the same manner as in Example 1. The blend ratio of the high-stretch, elongated false-twisted yarn in the knitted fabric was 50% by mass, and the blend ratio of the friction false-twisted yarn was 50% by mass. The composition of the knitted fabric in Example 2 and the evaluation results are shown in Table 1.

Example 3
A grey knitting machine having a knitting structure consisting of complete structures F1 to F4 shown in Figure 4 was produced using the same single circular knitting machine (JS type manufactured by Fukuhara Seiki Seisakusho) as in Example 1. The same highly stretchable false-twisted yarn as in Example 1 was used for all yarn feeders F1 to F4. The yarn length for yarn feeders F1 and F3 was 170 mm/100W. The yarn length for yarn feeders F2 and F4 was 230 mm/100W. The completed grey knitting machine was dyed and finished in the same manner as in Example 1. The structure of the knitted fabric of Example 3 and the evaluation results are shown in Table 1.

Example 4
The same knitting structure as in Example 3 was produced using the same single circular knitting machine as in Example 1. At this time, the same high-stretch, elongated false-twisted yarn as in Example 1 was used in yarn feeders F1 and F3, and knitting was carried out at a yarn length of 170 mm/100 W. Next, the same polyethylene terephthalate friction false-twisted yarn as in Example 2 was used in yarn feeders F2 and F4, and knitting was carried out at a yarn length of 230 mm/100 W. The blend ratio of the high-stretch, elongated false-twisted yarn in the knitted fabric was 40% by mass, and the blend ratio of the friction false-twisted yarn was 60% by mass. The finished grey fabric was dyed and finished in the same manner as in Example 3. The structure of the knitted fabric of Example 4 and the evaluation results are shown in Table 1.

Example 5
A 33-inch, 32-gauge double circular knitting machine (LPJ type manufactured by Fukuhara Seiki Seisakusho) was used to knit a greige knit consisting of the complete designs F1 to F6 shown in Figure 5 using interlock gauging. At this time, a semi-dull round cross-section 56T24f polyethylene terephthalate friction false-twist yarn (28.9% stretch elongation, -3.5% hot water dimensional change rate) was used as the yarn that formed the design on the other side of yarn feeders F1 and F4 and connected the front and back sides with tucks. Next, the same 84T48f highly stretchable false-twisted yarn as the yarn used in Example 1 was used as the yarn that formed the design on one side of yarn feeders F2 and F5. Furthermore, another highly stretchable false-twisted yarn, a 56T36f pin-twisted round cross-section fiber consisting of a side-by-side cross-section conjugate fiber of polybutylene terephthalate (50% by mass) and polyethylene terephthalate (50% by mass), was used as the yarn that formed the design on one side of yarn feeders F3 and F6. The stretch extension rate of this highly stretchable false-twisted yarn was 87.5%, and the hot water dimensional change rate was -9.9%. The yarn lengths of F1 and F4 were 200 mm/100W, those of F2 and F5 were 210 mm/100W, and those of F3 and F6 were 155 mm/100W. The blend ratio of 84T48f highly stretchable false-twisted yarn in the knitted fabric was 47% by mass, that of 56T36f highly stretchable false-twisted yarn was 23% by mass, and that of 56T24f friction false-twisted yarn was 30% by mass. The finished grey fabric was dyed and finished in the same manner as in Example 1. The structure of the knitted fabric of Example 5 and the evaluation results are shown in Table 1.

Example 6
A greige fabric was produced by interlacing an antistatic yarn at 15 mm intervals in the warp direction of the back structure of Example 5. Specifically, the complete design shown in Figure 5 was knitted once per 12 repeats by aligning a 22T1f antistatic yarn (White Belltron B68 manufactured by KB Seiren) with the F1 yarn at the yarn feeder F1. The completed greige fabric was dyed and finished in the same manner as in Example 5. The structure of the knitted fabric of Example 6 and the evaluation results are shown in Table 1.

Example 7
As in Example 1, a 30-inch, 36-gauge single circular knitting machine was used to knit a greige fabric consisting of the complete designs F1 and F2 shown in Figure 3. The yarn used was a highly stretchable false-twisted yarn made of polybutylene terephthalate with a semi-dull circular cross section and a pin-twisted finish of 84T24f (stretch elongation rate 55.6%, hot water dimensional change rate -5.4%), knitted at a yarn length of 175 mm/100 W. The finished greige fabric was dyed and finished in the same manner as in Example 1. The structure of the knitted fabric of Example 7 and the evaluation results are shown in Table 1.

(Comparative Example 1)
As in Example 1, a 30-inch, 36-gauge single circular knitting machine was used to knit a greige knitting machine consisting of the complete designs F1 and F2 shown in Figure 3. Instead of the highly stretchable false-twisted yarn, the yarn used was the 84T36f friction false-twisted yarn with a semi-dull circular cross section (stretch elongation 31.3%, hot water dimensional change rate -4.1%) interwoven in Example 2, knitted at a yarn length of 175 mm/100 W. The completed greige knitting machine was dyed and finished in the same manner as in Example 1. The structure of the knitted fabric of Comparative Example 1 and the evaluation results are shown in Table 1.

(Comparative Example 2)
As in Example 6, a 30-inch, 32-gauge double circular knitting machine was used to knit a greige knitting machine consisting of complete designs F1 to F6 shown in Figure 5. In this knitting, no highly stretchable false-twisted yarn was used in yarn feeders F2, F3, F5, and F6. Instead, the same friction false-twisted yarn as used in yarn feeder F2 in Example 2 was used in F2 and F5. The same 56T24f friction false-twisted yarn as used in yarn feeder F1 and F4 was used in F3 and F6. As in Example 6, a 22T1f antistatic yarn (White Belltron B68, manufactured by KB Seiren) was knitted into yarn feeder F1 once per 12 repeats of the complete design. The finished greige knitting machine was dyed and finished in the same manner as in Example 6. The structure of the knitted fabric of Comparative Example 2 and the evaluation results are shown in Table 1.

(Comparative Example 3)
Using the same 30-inch, 36-gauge single circular knitting machine as in Example 1, a greige machine with an all-knit complete design as shown in Figure 6 was knitted. The same 84T48f highly stretchable, elongated false-twisted yarn as in Example 1 was used for all yarn feeders. The yarn length at each yarn feeder was 260 mm/100 wales (W). The completed greige machine was dyed and finished in the same manner as in Example 1. The structure of the knitted fabric of Comparative Example 3 and the evaluation results are shown in Table 1.

(Comparative Example 4)
Using the same 30-inch, 36-gauge single circular knitting machine as in Example 1, a greige machine with an all-knit complete design as shown in Figure 6 was knitted in the same manner as in Comparative Example 3. Instead of the highly stretchable false-twisted yarn, the same 84T36f friction false-twisted yarn as the yarn used in yarn feeder F2 in Example 2 was used. The completed greige machine was dyed and finished in the same manner as in Example 1. The structure of the knitted fabric of Comparative Example 4 and the evaluation results are shown in Table 1.

As can be seen from Table 1, the knitted fabrics of Examples 1 to 7 exhibited excellent stretchability and anti-snag properties because the ratio of knit-tuck unit structures composed of highly stretchable, elongated false-twisted yarns on one side was within the range of the present invention. On the other hand, Comparative Examples 1 and 2 have knit-tuck unit structures, but are not composed of highly stretchable, elongated false-twisted yarns, and Comparative Examples 3 and 4 do not have knit-tuck unit structures at all. As a result, while they have stretchability, they exhibit poor anti-snag properties on one side. Furthermore, when antistatic yarns were included, the presence of the antistatic yarn was less noticeable in the knitted fabric of Example 6 than in Comparative Example 2.

The present invention can provide knitted fabrics that combine stretchability and snag resistance, making them suitable for clothing such as working uniforms. Furthermore, it can provide knitted fabrics that are difficult to see through even when colored antistatic yarns are used. Therefore, the present invention is extremely useful in industries that manufacture and sell such clothing.

Claims (4)

The knitted fabric is a single knit having knit-tuck unit structures on at least one surface thereof, at least a part of the knit-tuck unit structures being made from false-twisted yarn having a stretch elongation rate of 40 to 95%, the ratio of knit-tuck unit structures made from false-twisted yarn having a stretch elongation rate of 40 to 95% to the entire structure making up said one surface being 25 % or more and less than 100%, and at least one surface comprising both knit-tuck unit structures and all-knit unit structures. The knitted fabric described in claim 1, characterized in that the false-twisted yarn with a stretch elongation rate of 40 to 95% is made of conjugate composite fibers. The knitted fabric described in claim 1, characterized in that the course density on one side is 50 (pieces/2.54 cm) or more and 95 (pieces/2.54 cm) or less, and the wale density is 45 (pieces/2.54 cm) or more and 80 (pieces/2.54 cm) or less. The knitted fabric described in claim 2, characterized in that the conjugate composite fiber is made of polybutylene terephthalate and polyethylene terephthalate, and the knit-tuck unit structure composed of the false-twisted yarn of the conjugate composite fiber constitutes 40 to 100% of the weave that makes up one side.