JP2008069471A - Core yarn sewing thread and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core yarn sewing thread having excellent strength and sewability, improved appearance of stitches and excellent qualities. <P>SOLUTION: The core yarn composite filament yarn is obtained by winding a staple fiber bundle to be a sheath yarn on the periphery of a filament yarn to be a core yarn along the longitudinal direction with and is provided with a first twist at a twist multiplier K of 3.5-4.5 and has fluffs having a length of ≥1 mm at ≤250 fluffs/10 m. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a core yarn sewing thread excellent in sewability and seam cleanliness for industrial sewing and home sewing, and a method for producing the same.

  In recent years, as the sewing technology has been improved by increasing the speed and automation of the sewing machine, there has been a demand for a thinner or higher-strength thread while maintaining a conventional level of sewability. Conventionally, as a synthetic fiber sewing thread, one using 100% filament, one using 100% staple fiber, a core yarn using a filament thread and a sheath using a staple staple fiber are known. .

  The core yarn sewing thread is a composite spun yarn in which core yarn fibers made of long fiber yarns and sheath yarn fibers made of drafted short fiber bundles are aligned in a core / sheath shape and supplied to the front roller of the spinning machine. None, and then a plurality of the composite spun yarns are aligned and an upper twist is applied in a direction opposite to the twist direction of the composite spun yarn. This core yarn sewing thread is higher in strength than a spinning thread only, so it is used for sewing jeans that require durability, thin fabrics or suits that require a beautiful finish. Yes.

  On the other hand, the fluff of the short fibers constituting the sheath yarn of the core yarn sewing thread is more conspicuous than the filament sewing thread having a filament yarn composition ratio of 100%. It was difficult to expand into high-end clothing products.

  As a technique to improve the fundamental problem of these core yarn sewing threads, for example, long fiber yarns already subjected to lower twist and normal span yarn are aligned and twisted with a twister. There has been proposed a “polyester mixed-twisted sewing thread” made of a composite yarn having a twisted structure (see, for example, Patent Document 1).

  Although this sewing thread is a reasonably manufactured mixed twist sewing thread, the long fiber yarn is completely covered with the span yarn on the combined twist structure, so the sewing property is low, and the long fiber yarn and the short fiber Since the dyeing difference and gloss difference with the yarn are easily noticeable, the quality of the core yarn sewing thread was low.

  In addition, the core filaments that have been electrospread by static electricity are uniformly distributed in the cross section of the short fibers that form the sheath yarn, a core yarn is manufactured by composite spinning, and a plurality of core yarns are drawn. A "composite sewing thread" having a high strength and a high breaking elongation that has been twisted together has been proposed (see, for example, Patent Document 2).

  This composite sewing thread is excellent in terms of sewing properties and uniform dyeability between the core / sheath, but by passing through the electric opening process, the manufacturing cost increases and fluff is likely to occur during the process. Therefore, there is a problem in that the quality is low and the elongation tends to be high, so that the buckling of the seam is likely to occur.

  Furthermore, other core yarn manufacturing apparatuses and manufacturing methods thereof have been proposed (see, for example, Patent Document 3), and further, a two-layer structured yarn and a manufacturing method thereof have been proposed (see, for example, Patent Document 4).

  These devices and methods include a hollow guide shaft body in which a yarn passage is formed in the nozzle axis direction, and a spinning section including a spinning section including a swirling flow generating nozzle that causes a swirling flow to act on the tip portion thereof, and a drafted short fiber This is a core yarn technique in which a bundle is wound around a long fiber supplied to a spinning section.

  The sewing thread made using this technology has fewer fuzz and beautiful seams, but the swirling airflow entangles the short fibers around the long fibers, so the finished sewing thread is soft. Therefore, there was a drawback that it was not possible to cope with complicated seams such as zigzag.

  Further, as a measure for reducing the generation of fluff, a method of fluffing through an air nozzle after a draft portion in the spinning process has been proposed (see, for example, Patent Document 5). Although the method of pulling out is completely different, the fluff itself is surely turned down, but basically it becomes a spun yarn that does not have a real twist to give the yarn strength by binding the fibers, and has a real twist similar to a ring spinning machine Is completely different in structure, and has a drawback that the texture becomes stiffer than the ring yarn.

  In other words, none of the conventional techniques has been proposed as a sewing thread that satisfies the fineness and high strength characteristics, and has excellent sewing properties and quality.

As described above, as for the core yarn sewing thread having the performance excellent in the sewing property and the thread appearance, it is a fact that a sufficient one has not been obtained yet.
Japanese Patent Laid-Open No. 02-33341 Japanese Patent Publication No. 63-3777 JP 2002-69760 A JP 2002-69774 A JP-A-8-158167

  An object of the present invention is to solve such problems of the prior art, and to provide a core yarn sewing thread excellent in strength and sewability and excellent in quality with improved appearance of seams. is there.

In order to solve the above problems, the present invention has the following configuration. That is,
(1) A short fiber bundle as a sheath yarn is wound around the long fiber yarn as the core yarn along the longitudinal direction at a weight ratio of 30% to 60%, and the twist coefficient K is K = 3. A core yarn composite fiber yarn characterized in that the number of fluffs of 1 mm or more, to which a lower twist is imparted in a range of 5 to 4.5, is 250/10 m or less.

  (2) A core yarn sewing thread, wherein a plurality of the core yarn composite fiber yarns according to (1) are aligned and an upper twist is applied in a direction opposite to the lower twist.

(3) The average tensile strength is 4.5 cN / dtex or more, the bending hardness is 0.002 gfcm ² / piece or less, and the bending recovery property is 0.002 gfcm / piece or less, as described in (2) above Core yarn sewing thread.

  (4) The core yarn sewing thread according to (2) or (3), wherein the lower twist direction of the core yarn composite fiber yarn is the S direction and the upper twist direction is the Z direction.

  (5) When spinning the core yarn composite fiber yarn according to (1), a fiber converging delivery roller having a mesh portion is provided between the front roller of the ring spinning machine and the snail wire, and the mesh portion of the delivery roller A method for producing a core yarn composite fiber yarn, wherein twisting is performed while adsorbing a fiber bundle, and drafting is performed at a magnification of 1.0 times or less between the delivery roller and the front roller.

  According to the present invention, the short fiber that becomes the sheath yarn can be reduced in fluff, and has a beautiful yarn surface that cannot be obtained by the prior art, and provides a fine yarn count and high strength core yarn sewing thread. it can.

  In addition, it has been considered impossible to apply real twist while fuzzing with conventional spun yarn. However, yarn can be spun by using the technology of the present invention, and high-speed sewing and household use are possible. A high-performance core yarn sewing thread that has excellent machineability and can be reduced in the sewing process can be obtained. Furthermore, it has the effect that the surface of the seam after sewing looks beautiful and the quality becomes excellent.

  The present invention has solved the above-mentioned problems, and as a result of earnestly examining high-performance core yarn sewing threads that are less susceptible to thread breakage during sewing and that allow easy adjustment of the sewing conditions of the sewing machine, When I tried to make a thread by aligning a plurality of threads and making an upper twist, I found out that this problem could be solved all at once.

  The best mode of the core yarn sewing thread of the present invention will be described below.

  First, as described above, the core yarn composite fiber yarn of the present invention is substantially twisted by winding a short fiber bundle serving as a sheath yarn around the long fiber filament yarn serving as a core yarn along the longitudinal direction thereof. It is characterized by a core yarn composite fiber yarn having 250 k / 10 m or less of fluff of 1 mm or more to which a lower twist is imparted in a coefficient K of 3.5 to 4.5.

  Moreover, the core yarn sewing thread of the present invention is characterized in that a plurality of the core yarn composite fiber yarns are further twisted and an upper twist is applied in a direction opposite to the lower twist.

  In addition, the core yarn sewing thread of the present invention is preferably twisted by combining two or three of the above composite fibers and applying an upper twist. If the number is less than 2, the strength required for the sewing thread cannot be obtained, and this is not preferable because it causes sewing or thread breakage. On the other hand, if the number is 4 or more, it is difficult to twist the yarn, and the uniformity of the yarn is impaired and the sewability is lowered.

  Here, as a core yarn, it is needless to say that any ordinary synthetic fiber can be used, but among these, fiber yarns such as polyester and polyamide are suitable. Also, aromatic polyamide and polyethylene fibers, which are called high-functional fibers, elastic fibers such as polyurethane, and cellulose fibers can be easily applied. Although not particularly limited, the strength of the finished core yarn thread is 4 cN. In view of the fact that it is preferably at least / dtex, the strength of the long fiber filament yarn that becomes the core yarn is preferably at least 6 cN / dtex, more preferably at least 7 cN / dtex. Moreover, it is preferable that it is 8 cN / dtex or less.

  The total filament fineness of the long fiber filament yarn is preferably in the range of 30 to 200 dtex, and the number of single filaments is preferably in the range of 12 to 200. For example, the fineness of the long fiber filament yarn is More preferably, the yarn configuration is 12 to 30 for 33 dtex, 15 to 28 for 44 dtex, 18 to 48 for 56 dtex, and 24 to 72 for 78 dtex. This is because when the fineness of the single fiber is increased, the sewing thread becomes harder and the seam is raised from the fabric. On the other hand, if it becomes thin, fluffing occurs or strength is reduced from the twisting process to the final finishing process, so it is necessary to select appropriately.

  As the sheath yarn, not only all the usual synthetic fibers like the core yarn but also polyester and polyamide are suitable, and natural fibers such as cotton, silk or cellulose and acrylic fibers can be easily applied. Can do. In the present invention, the short fiber constituting the core yarn is a raw material for spun yarn, a futon cotton, a stuffed cotton, and the like, and as a specific form, a staple fiber or simply called a staple Etc.

  As the staple fiber, the single fiber fineness is preferably in the range of 0.5 to 3 dtex, and the range of 0.7 to 1.5 dtex leads to the spinning property such as card passing property, or the softness of the core yarn sewing thread, which leads to a high sewability. So it is more preferable. Also, the fiber length may be any of a short spinning type of about 30 mm to 51 mm and a long spinning type of 51 to 90 mm, but the former is because of the high strength characteristics because of the cleanness after sewing the core yarn sewing thread. The latter spinning method is preferred.

  In the fine spinning method used in the present invention, the number of sheath yarns wound around the core yarn, that is, the number of cross-sectional configurations necessary for forming a so-called short fiber yarn is 40 or more. While the minimum number of cross-sectional structures required for ring spinning is said to be at least 60, the present invention can realize spinning with a finer count. The upper limit is not particularly limited, but is preferably 300 or less. Exceeding 300 is not preferable because it tends to stiffen and cause yarn unevenness. If the number is less than 40, the winding property is poor, which is not preferable.

  The short fiber bundle serving as the sheath yarn is preferably in the range of 30% by weight to 60% by weight with respect to the total yarn amount including the core yarn. When the amount is less than 30% by weight, the core yarn is easily exposed and the strength is also low, so that winding failure and unraveling are likely to occur, and the formation of the core yarn becomes insufficient. On the other hand, when the amount exceeds 60% by weight, the core yarn is not exposed, but the strength is apt to decrease greatly.

  As a method for measuring the weight of the sheath yarn, the core yarn and the sheath yarn are disassembled from the core yarn sewing thread having a length of 1 inch (2.54 cm) using a magnifying glass, and only the short fiber wound with the sheath yarn is taken out and its weight is taken. Measure (g). The weight is calculated as a weight ratio with respect to the total yarn weight.

  Next, this core yarn composite fiber yarn is twisted in the range where the twisting coefficient K is K = 3.5 to 4.5 to give a real twist. If the twist coefficient is less than the above range, the strength becomes insufficient, and the beauty of the seam due to the reduction in fluff, which is a feature of the present invention, is impaired. On the other hand, if the twisting coefficient exceeds the above range, the strength of the sewing thread increases, but this is not preferable because it leads to the rigidity of the finished sewing thread and affects the high sewability.

The twist coefficient K = T / (Ne) ^1/2
T: Number of twists per inch (2.54 cm) of core yarn composite fiber yarn Ne: Expressed in English cotton count of core yarn composite fiber yarn.

  The number of fluffs of the core yarn sewing thread is preferably 250 or less per 10 m. When the number is 250 or less, it is possible to suppress the fluff from being too conspicuous and maintain the quality of the seam. Further, the lower limit is preferably as small as possible, but if it is too small, the dissipation of needle heat does not go well, and this has an effect on the high sewability, which is not preferable. Therefore, 50 to 200 pieces / 10 m are more preferable.

  Hereinafter, the production method of the present invention will be described in more detail based on the embodiments shown in the drawings.

  The core yarn composite fiber yarn manufacturing method of the present invention includes a fiber convergence delivery roller having a mesh portion between a front roller and a snail wire of a ring spinning machine, and after passing while adsorbing a fiber bundle at the mesh portion of the roller And twisting to give a real twist.

  FIG. 1 is a side view showing an example of an apparatus in which a fiber converging delivery roller for fuzz twisting is provided at a spinning portion of a ring spinning machine of the present invention. FIG. 2 is a detailed view of the fiber convergence delivery roller portion in FIG.

  In FIG. 1, using a staple fiber after the drawing process of the spinning process, that is, a short fiber bundle, the fiber bundle is spun from the front roller 3, and from a delivery roller constituted by a fiber convergence delivery roller 1 and a delivery nip roller 2. The inserted long fiber yarn 8 and the drafted short fiber bundle 9 are drawn together by the delivery roller 2 and wound as a core yarn composite fiber yarn 6 on the bobbin of the winding spindle 5 through the snail wire 4. In the manufacturing method of the present invention, the fiber convergence delivery roller 1 is provided between the front roller 3 and the snail wire 4. The delivery nip roller 2 is for controlling the convergence of the fiber bundle on the fiber convergence delivery roller 1.

  The fiber converging means used in the manufacturing method of the present invention is a fiber converging delivery roller 1, and as shown in FIG. 2, a cylindrical resin mesh apron 7 is fitted on the surface of the delivery roller 1. It is designed to go around. The fiber convergence delivery roller 1 is provided with a plurality of slits, and air is sucked from the inside through the slits and the mesh apron 7 by air suction means (not shown). Using the force of air suction, the direction of fluff generated on the surface of the spun yarn is made uniform by sticking the fiber bundle on the cylindrical mesh apron 7 that circulates on the surface of the fiber convergence delivery roller 1. Usually, the fluff generated on the surface of the yarn is twisted into the spun yarn.

  One cause of the fluff of the spun yarn is that the tip of the single fiber that could not be twisted protruded from the yarn surface. The direction of the single fibers protruding from the yarn surface is usually random, but before twisting, the fibers are sucked on the mesh apron 7 of the fiber convergence delivery roller 1 so that the directions of the single fibers protruding from the yarn surface are aligned. By this, the fluff can be twisted. Further, at this time, drafting between the front roller 3 and the delivery nip roller 2 at a magnification of 1.0 times or less enhances the suction effect at the mesh portion and assists in aligning the direction of the short fibers. is there. If the processing exceeds this magnification, the yarn is slackened between the front roller 3 and the delivery nip roller 2 to form a core yarn composite fiber yarn, which leads to defects such as loops. Conversely, when processing at a magnification of 0.7 times or less, the suction effect at the mesh portion cannot be sufficiently exhibited, so the preferable processing magnification is 0.7 to 1.0 times.

  As the winding direction of the sheath thread, since the final use is a sewing thread, the S direction which is the same as the lower twisting direction of the general sewing thread is preferable, and conversely, the twisting torque becomes strong in the Z direction, resulting in poor process passage. That is, the core yarn sewing thread according to the present invention is obtained by twisting a plurality of core yarns in which the twist coefficient K is twisted in the range of K = 3.5 to 4.5 in the same direction as the yarn winding direction and the lower twist is inserted. This is a core yarn sewing thread having a structure in which the upper twist is inserted in the Z direction opposite to the lower twist direction.

  Further, the upper twist number is preferably 60% to 90%, more preferably 70% to 80% of the lower twist number described above. If the upper twist number is less than 60% of the lower twist number, the gap between the fibers becomes large, and the sewing needle passes through it during sewing, causing thread breakage. Further, if the upper twist number is more than 90% of the lower twist number, the torque balance is poor, which causes skipping during sewing, which is not preferable.

  After the bottom is applied in the spinning process, heat setting is performed for the purpose of stopping the shrinkage or eliminating the residual torque after the bottom. Also, depending on the purpose of the sewing thread, after a plurality of threads are combined and an upper twist is applied, similarly, heat setting is performed for the purpose of stopping the shrinkage or eliminating the residual torque from below. After setting, soft-wound cheese is made, dyed with cheese, and finished with a core yarn thread product.

  Next, in general, the higher the average tensile breaking strength of the core yarn sewing thread of the present invention, the better the durability and the sewability, and 4.0 cN / dtex or more is preferable for thick ground or jeans. Moreover, 3.5 cN / dtex is sufficient as a sewing thread used for a normal clothing fabric. However, if it is higher than 5.0 cN / dtex, a large load is applied to the sewn product and damages the fabric near the seam, which is not preferable, and 5.0 cN / dtex or less is preferable.

In addition, the softness of the sewing thread is also required in order to cope with a wide range of sewability that can be used not only for industrial purposes but also for household sewing threads. The core yarn sewing thread of the present invention was able to realize a bending hardness of 0.002 gfcm ² / piece or less and a bending recovery property of 0.002 gfcm / piece or less by the above-described fine spinning method. Also, if it is too soft, complicated patterns such as zigzag stitches such as zigzag stitches will be sewn, and the upper thread will not save the lower thread well, and a thread jumping phenomenon will occur. Therefore, the bending hardness is usually 0.0005 gfcm ² or more The bending recovery property is preferably 0.0005 gfcm / piece or more.

  The core yarn sewing thread obtained in this way has a high convergence as compared with the conventional product because the sheath yarn has a uniform and tight winding property. In addition, since the number of fluff is extremely small compared with the conventional ring spinning type core yarn sewing thread, the core yarn sewing thread has an excellent effect that the thread appearance and the seam are beautifully finished.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  The measurement method was as follows.

(1) Apparent fineness, count, dry heat shrinkage, boiling water shrinkage 20 samples per level were measured according to JIS L1013 (1999), and the average value was calculated.
(2) Average tensile rupture strength, average tensile rupture elongation Using STATIMA ME manufactured by Keiki Kogyo Co., Ltd., measuring 20 samples per level at a grip length of 200 mm and a tensile speed of 100% / min, the average tensile rupture strength (CN) and average tensile breaking elongation (%) were determined.
The average tensile strength at break (cN / dtex) was calculated from the average tensile strength at break and the apparent fineness measured in (1).

(3) Number of fluffs Using an electrostatic capacitor while unwinding at a speed of 30 m / min, the number of surface fluffs protruding from 1 mm, 3 mm, 5 mm or more for each yarn diameter was counted. is there. The data in the table is the number of fluff per 10 m length (pieces / 10 m), and is an average value measured 10 times for each fluff length.

  In addition, according to JIS L1095 (1999) (general spun yarn test method) 9.22 B method, the measuring apparatus measured using Shikishima Techno Co., Ltd. F-INDEX TESTER.

(4) U%
Measurement was performed using an EVENNESS TESTER 80 manufactured by Keiki Co., Ltd.

(5) Amount of winding of sheath yarn Using a magnifying glass, disassemble the core yarn and the sheath yarn from the core yarn sewing thread of 1 inch (2.54 cm) in length, take out only the short fiber wound around the sheath yarn, and its weight ( g) is measured. The weight is calculated as a weight ratio with respect to the total yarn weight.

(6) Bending properties (bending hardness, recoverability)
Measurement was performed using KES-FB manufactured by Kato Tech Co., Ltd. 60 yarns are used for one measurement, and the bending hardness and recoverability per piece are calculated by division.

(7) Sewing property evaluation method High-speed sewability (advanced sewing): The maximum number of rotations (needle / min) that can be sewn without thread breakage was measured with a sewing machine capable of sewing 10 sheets of T / C broad fabric and sewing 2m. Measurements were tested in the range of 1000 to 5000 (needle / min).

B. Back sewability (back stitching): Four T / C broad fabrics were stacked, and the number of thread breaks (average number / 10 times) when sewing 1 m at 1500 (needle / min) with a sewing machine was measured. The evaluation criteria were as follows.
×: Sewing is impossible or 6 times or more Δ: 2 to 5 times ○: 1 to 2 times ○ ○: 0 times.

C. Zigzag stitch sewing (household use): Two T / C broad fabrics are stacked, and the stitch defects (mesh skipping) when 0.5m is sewn with zigzag stitch (sewing pitch 1.4mm, zigzag width: 4mm) on a sewing machine. The number of occurrences of defective seams) was measured. The number of needle rotations was 300 spm (stitch / min). The evaluation criteria were as follows.
X: 6 times or more Δ: 3-5 times ○: 1-2 times ○○: 0 times.

D. Seam quality: Samples sewn at a rotational speed of 1000 (needle / min) were visually evaluated in the high-speed sewability (advanced stitching) evaluation in Section A.
Δ: Lots of fluff.
○: Fluff can be found.
○○: Fuzz is hardly noticeable.

Example 1
First, a polyester multifilament 56 dtex-36 filament yarn having a strength of 7.1 cN / dtex as a core yarn is supplied from the front of the delivery nip roller 2 in FIG. Using a sliver with a single fiber fineness of 0.8 dtex and a fiber length of 35 mm, the polyester raw cotton is mounted on a ring spinning machine having a roller-type draft mechanism, and the fiber convergence delivery roller 1 of FIG. 2 is installed directly under the front roller 3. A core yarn composite fiber yarn having a cotton count of 60 s was obtained with a twist coefficient of K = 4.0, a twist direction of S, and a spindle rotation speed of 12000 rpm.

Then, in order to produce two twist yarns of the core yarn, the upper twist number was given 80% of the lower twist coefficient in the Z direction to produce a two-core twist core yarn.
Next, roll the two-core twisted core yarn onto the cheese and apply a steam set at 95 ° C. for 30 minutes as a twist-stop treatment, then roll it up on soft cheese, scour it at 60 ° C. for 10 minutes, and after relaxing, 130 ° C. The cheese was dyed for 40 minutes and finished in black to produce a core yarn sewing thread.
The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.

Example 2
The single fiber fineness of the polyester multi-filament 44 dtex-18 filament of 6.2 cN / dtex of the long fiber yarn used as the core yarn and the polyester raw cotton of the short fiber bundle used as the sheath yarn is 1.3 dtex, and the fiber length is 38 mm. A core yarn sewing thread was finished in the same manner as in Example 1 except that it was used.

The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.
From Table 1, Example 1 has excellent performance in all industrial applications such as high-speed sewing and compatibility with automatic machines, and can also cope with complicated zigzag stitches used for home use. . Further, the number of fluff was small, the finish of the seam was beautiful, the yarn unevenness U% was low, and the yarn streak was smooth. In Example 2, the long fiber and the short fiber as raw materials were changed, and the strength of the long fiber was slightly lowered, so that the strength of the finished sewing thread was slightly lowered. Therefore, in the high-speed stitchability, the occurrence of thread breakage was observed at 3800 stitches / minute, and the seam quality almost the same as in Example 1 was exhibited.

Comparative Example 1
Next, using the same long fiber yarn and short fiber bundle as in Example 1, a core yarn composite fiber having a cotton count of 60S was obtained by normal ring spinning without a fiber convergence delivery roller with the same twist coefficient as in Example. Further, a core yarn sewing thread was finished in the same manner as in Example 1.
The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.

Comparative Example 2
The fiber convergence delivery roller 1 is installed just below the front roller 3 and spun in the same manner as in Example 1 except that the long fiber yarns and short fiber bundles as in Example 1 are used and the coefficient K is set to 3.2. The core yarn composite fiber yarn of cotton count 60S was obtained. Further, a core yarn sewing thread was finished in the same manner as in Example 1.

  The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.

Comparative Example 3
The fiber convergence delivery roller 1 is installed just below the front roller 3 and spun in the same manner as in Example 1 except that the long fiber yarn and the short fiber bundle as in Example 1 are used and the coefficient K is set to 4.7. The core yarn composite fiber yarn of cotton count 60S was obtained. Further, a core yarn sewing thread was finished in the same manner as in Example 1.

  The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.

Comparative Example 4
Using the same long fiber yarn and short fiber bundle as in Example 1, the long fiber yarn is supplied from the front of the front roller 3 as shown in FIGS. 3 and 4, and the draft magnification of the delivery roller 2 to the front roller 3 is A core yarn sewing thread was finished in the same manner as in Example 1 except that it was set to 1.009.

  The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.

Comparative Example 5
Using the same long fiber yarn and short fiber bundle as in Example 1, the long fiber yarn is supplied from the front of the front roller 3 as shown in FIGS. 3 and 4, and the draft magnification of the delivery roller 2 to the front roller 3 is A core yarn sewing thread was finished in the same manner as in Example 1 except that 1.029 was set.

  The properties of the obtained core yarn sewing thread and the results of the sewability evaluation are shown in Table 1 described later.

  From Table 1, since the normal spinning method is used in Comparative Example 1, since there are many fluffs, the fluff tips are conspicuous on the surface of the seam, and the fabric sewing using filament yarn is extremely noticeable and becomes a defect.

  In Comparative Example 2, since the twist coefficient is low, the strength of the sewing thread tends to be insufficient, and the high-speed stitchability is slightly low. In addition, since the number of fluff was slightly larger, the appearance of the seam was also affected.

  In Comparative Example 3, since the twist coefficient was high, the finished sewing thread was seen to be slightly stiff. For this reason, the high-speed sewing performance was cut at 2800 stitches / minute and dropped slightly.

  In Comparative Examples 4 and 5, there was no problem in spinning in the spinning process, but since the draft magnification between the delivery roller 2 and the front roller 3 exceeded 1, the core yarn composite fiber was slightly spun at the time of spinning. There was a slight loop on the finished core yarn thread. Therefore, the evaluation of the sewing property and the thread quality deteriorated.

  For general garments that require high-speed sewing for industrial use, automatic machine-compatible sewing, back sewing, and clean seams that can handle complex patterns such as zigzag stitches for home use, for example, long and short composite yarns As a result, it can be applied to luxury women's clothing and men's pants that take advantage of its excellent elasticity and waist texture.

It is a side view which shows the apparatus which provided the fiber convergence delivery roller for fiber convergence in the spinning part of the ring spinning machine used in Examples 1-2 and Comparative Examples 2-3. FIG. 2 is a detailed view of a fiber convergence delivery roller portion in FIG. 1. It is a side view which shows the apparatus which provided the fiber convergence delivery roller for fiber convergence in the spinning part of the ring spinning machine used in Comparative Examples 4-5. FIG. 4 is a detailed view of a fiber convergence delivery roller portion in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fiber convergence delivery roller 2 ... Delivery nip roller 3 ... Front roller 4 ... Snail wire 5 ... Spindle 6 ... Core yarn composite fiber yarn 7 ... Mesh apron 8 ... Long fiber yarn supply position 9 ... ... short fiber bundle

Claims (5)

A short fiber bundle as a sheath yarn is wound around the long fiber yarn as the core yarn along the longitudinal direction at a weight ratio of 30% to 60%, and the twist coefficient K is K = 3.5 to 4 Core yarn composite fiber yarn characterized in that the number of fluffs of 1 mm or more and 250 pieces / 10 m or less provided with a lower twist in a range of .5. A core yarn sewing thread, wherein a plurality of the core yarn composite fiber yarns according to claim 1 are aligned and an upper twist is applied in a direction opposite to the lower twist. 3. The core yarn sewing thread according to claim 2, wherein the average tensile breaking strength is 4.0 cN / dtex or more, the bending hardness is 0.002 gfcm ² / piece or less, and the bending recovery property is 0.002 gfcm / piece or less. The core yarn sewing thread according to claim 2 or 3, wherein the lower twist direction of the core yarn composite fiber yarn is the S direction and the upper twist direction is the Z direction. When spinning the core yarn composite fiber yarn according to claim 1, a fiber converging delivery roller having a mesh portion is provided between the front roller of the ring spinning machine and the snail wire, and the fiber bundle is adsorbed by the mesh portion of the delivery roller. And producing a core-yarn composite fiber yarn, wherein the yarn is drafted at a magnification of 1.0 times or less between the delivery roller and the front roller.

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