JPH09228178A - Production of machine sewing thread - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a machine sewing thread made of a spun yarn-like polyester multifilament having naps and having excellent sewing properties. SOLUTION: After a polyester multifilament yarn is treated for giving primary twist, false twist is given to the polyester multifilament yarn in the opposite direction to the primary twist and at the same time a part of the filaments of the multifilament yarn is cut in a twisting body containing a rough surface. Thus obtained spun yarn-like polyester filament yarn is treated for giving final twist in the opposite direction to the primary twist to produce a twisted union yarn 10. Subsequently, the obtained twisted union yarn 10 is subjected to hot drawing and a relaxation heat treatment to produce the object machine sewing thread excellent in sewing properties.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sewing machine thread, and more particularly, it has the same homogeneity as a filament sewing machine thread and has the same ease of handling as a spun sewing machine thread. The present invention relates to a method for manufacturing a new sewing thread having a thread.

[0002]

2. Description of the Related Art Polyester spun yarn, which is generally used as a sewing thread, is often used in the case where a thin and beautiful appearance is required because the stain on the seam caused by the thread unevenness and the manufacturing cost greatly increase if the thread becomes thinner. A filament sewing thread is often used. A filament sewing machine thread that uses polyester multi-filament yarns can generally have a high tensile elastic modulus, so stitch defects called stitch skipping during sewing do not occur easily, and the variation in tensile strength is small There are few thread breakages at the time. In addition, the filament sewing thread has a feature that it has few thread spots and beautiful stitches. However, when sewing at high speed using a filament sewing thread, the sewing needle often reaches a temperature that exceeds the melting temperature of the thread, which causes a problem that the thread melts when stopped. Further, since the sewing thread has no fluff, there is no proper friction between the cloth and the thread, and the defect that the seam floats from the cloth easily occurs, which is also a problem of the filament sewing thread.

As a method for improving the above-mentioned drawbacks of the filament sewing machine thread, an abrasion body or a grindstone is applied to a polyester multifilament as disclosed in JP-A-50-82342, JP-A-51-136947, JP-A-2-216233 and the like. A method of using fluffed yarns has been proposed, such as a method of applying a fluff or a method of rubbing one's own threads after entanglement treatment with twisted threads or high-pressure air fluid. However, since such a fluffed yarn causes minute fluctuations in the length of the multifilaments constituting the sewing yarn using the yarn, the tensile elasticity is low and the sewing property is not always good. It's not.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a sewing thread in which fluff is imparted to a polyester multifilament to give good sewing properties to the sewing thread by an inexpensive method.

[0005]

The present invention employs the following means to solve the above-mentioned problems. That is, the present invention is to combine a plurality of spun yarn-like polyester multifilament yarns that have undergone undertwisting and partially cut multifilaments, and reverse the direction of the undertwist of the spun yarn-like polyester multifilament yarns. The method for producing a sewing machine yarn is characterized in that the twisted yarn is subjected to a ply twist in the direction of to form a plied yarn, and then the plied yarn is subjected to hot drawing and relaxation heat treatment.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below. The spun yarn-like polyester multifilament yarn used in the present invention, in which a part of the multifilament is cut, is a part of the multifilament obtained by pressing the filament against a sharp substance such as a bite to run the filament. It can also be obtained by twisting the obtained yarn after cutting, but in general a method of fluffing a part of the multifilament by such a method causes a large decrease in the strength and elongation of the thread, and the poor twistability and strength. It is impossible to obtain suitable thread characteristics for the application of sewing thread that requires Therefore, the spun yarn-like polyester multifilament yarn is preferably obtained by the following method. That is, after the polyester multifilament is subjected to priming, a spun yarn is obtained by applying a false twist in a direction opposite to the priming direction with a twisted body including a roughened body and simultaneously cutting a part of the multifilament. This is a method for obtaining a polyester multifilament yarn. The spun yarn-like polyester multifilament yarn obtained by this method has a small decrease in the strength of the yarn and is preferable for use in sewing machine yarn.

A method of subjecting the polyester multifilament to initial twisting, and then performing false twisting in a direction opposite to the initial twisting direction with a twisted body including a roughened body and cutting a part of the multifilament at the same time. Will be explained in a little more detail. FIG.
Shows the outline of this method. As a method for imparting the lower twist, an up twister method is preferable, and a double twist method is particularly preferable in that the tension applied to the yarn at the time of twisting is constant, the quality is good, and the productivity is high. The polyester multifilaments 1, 1 ', 1 "to be used are pre-wound on a bobbin and mounted on a holder of a twisting machine not shown. The rotary disks 2, 2', 2" are rotated by a driving machine via a belt to twist the yarn Hang The twisted polyester multifilament is a tension device 3, guides G2, G2 ', G
2 ”and is guided to a twisted body 4 including a rough surface body, and the twisted body 4
Then, a false twist is applied in the opposite direction to the twist direction given by the rotary discs 2, 2 ', 2 ", and a part of the polyester multifilaments can be easily formed on the twisted body 4 with very little twist. Immediately after passing through the twisted body 4, the lower twist applied by the rotary disks 2, 2 ', 2 "returns to the yarn. G1, G1 'and G1 "are guides.

The spun yarn-like polyester multifilament yarns provided with fluff can be wound one by one or a plurality of fibers at the same time, but as shown in FIG. When the bobbin 8 is wound by the type twisting machine 7, the process can be shortened, which is rational. Normally, the number of twists of the upper twist is smaller than that of the lower twist by the reciprocal number of the square root of the fineness, but it is difficult to increase the number of rotations of the upper twist ring twister more than the lower twist double twister. In the ring type twisting machine 7, it is preferable to give a twist number of about 30% to 80% of the preset twist number. In addition, 5 is a take-up roller, G4 is a guide, and 6 is a snail wire.

The plied yarn 8 wound up by the ring type twisting machine 7 is mounted on the double twisting machine of FIG. 2 and the remaining twist number of the set twist number of the upper twist is given. Double twisted yarn 10 with a set number of twists
Is stretched between the rollers 12 and 14 via the heater 13 and subsequently subjected to a relaxation heat treatment between the rollers 14 and 16 via the heater 15 and then the take-up roller 18.
Is wound up on the package 17.

In general, a spun yarn-like polyester multifilament yarn subjected to undertwisting has a low tensile elastic modulus due to a decrease in fiber orientation between the multifilaments at the stage of providing fluff. The inventor has found out that this is the cause of not improving the sewability of the sewing thread using the spun yarn-like polyester multifilament yarn, and has reached a method of hot drawing. A method of independently hot drawing a spun yarn-like polyester multifilament yarn having been twisted is also conceivable, but the orientation is disturbed again at the stage of twisting and it is difficult to obtain a sufficient effect. A sufficient effect can be obtained only when a plurality of threads used as sewing threads are heat-stretched in a twisted state. The conditions for hot stretching are preferably a stretching temperature of 80 ° C. to 230 ° C. and a stretching ratio of 1.02 to 1.25. If the drawing temperature is less than 80 ° C., the drawing is not carried out uniformly, and a preferable yarn structure having a uniform filling structure without spots cannot be obtained. If the stretching temperature exceeds 230 ° C., the fibers are thermoset and lead to thread breakage during sewing, which is not preferable. Further, if the draw ratio is less than 1.02, the degree of orientation of the fiber in the axial direction of the yarn decreases, and a sufficient effect cannot be obtained. If the draw ratio exceeds 1.25, the number of yarn breakages in the draw stage increases and the operation becomes difficult, which is not preferable.

The relaxation heat treatment condition of the drawn plied yarn is preferably higher than the drawing temperature and in the range of 150 ° C to 240 ° C, and the relaxation ratio during the heat treatment is 0.85 to 0.9.
It is preferably in the range of 9. By the drawing treatment, the twisted yarn increases the orientation of the fibers, but at the same time, the heat shrinkage property also increases. The relaxation heat treatment is intended to remove this heat shrinkage, and this reduces the decrease in the tensile elastic modulus of the plied yarn during dyeing. If the relaxation treatment temperature is lower than 150 ° C, a sufficient relaxing effect cannot be obtained, and if it exceeds 240 ° C, the fiber is thermoset, which is not preferable. On the other hand, if the relaxation ratio exceeds 0.99, the effect of thermal relaxation is low, and if it is less than 0.85, yarn breakage during relaxation is increased, which is not preferable in operation.

[0012] The spun-like multifilament twisted yarn obtained in this way, which has a highly oriented fiber in the yarn and a low residual shrinkage, is a yarn and a needle at the time of sewing after dyeing with a cassette or cheese. It is wound on a bobbin by applying a finishing oil that has the effect of reducing the wear of the.

[0013]

【Example】

Example 1 Hereinafter, the present invention will be described in more detail with reference to Examples carried out using the apparatus shown in FIGS. Polyester multifilament produced by ordinary spinning and drawing methods has a breaking strength of 5.1 g / denier, a breaking elongation of 34% and a dry heat of 16
A yarn having a heat shrinkage of 12% at 0 ° C., a fineness of 63 denier and a filament number of 108 was used.

The polyester multifilament yarns 1, 1 ', 1 "are wound into a pan using an ordinary pan winder, set in a holder (not shown), and a rotary disk is rotated to twist 1250 times / m in the twist direction Z. 6 g of tension was applied by the tension devices 3 to 3 ″, and the yarn was raised to the yarn raising device 4. The yarn raising device 4 is a triaxial circumscribed twisted body disclosed in Japanese Patent Laid-Open No. 4-240237, in which three rough surface discs having a surface roughness of 20 s are mounted. A part of the multifilament which the polyester multifilament comprises is cut while imparting false twist in the false twist direction S by the yarn raising devices 4 to 4 ″, and then the three filaments are combined by the roller 5 to the ring type twisting machine 7. It was wound on a bobbin 8 after being twisted in the S direction at a rate of 500 times / m.

Subsequently, the bobbin 8 was additionally twisted at 400 turns / m in the S direction using the apparatus shown in FIG. 2, and then the plied yarn was drawn between the rollers 12 and 14 at a draw ratio of 1.12 and a temperature of 190 ° C. 10 was stretched, and then a relaxation treatment was performed between the rollers 14 and 16 at a relaxation ratio of 0.98 and a temperature of 220 ° C., and the bobbin 17 was wound up. By the way, the stretch ratio and the relaxation ratio were calculated by the following formulas. Stretching ratio = Surface speed of roller 14 / Surface speed of roller 12 Relaxation ratio = Surface speed of roller 16 / Surface speed of roller 14 The wound yarn wound on the bobbin 17 is wound on a soft-rolled cheese, dyed at 130 ° C and then siliconized. It was possible to obtain a sewing thread of the present invention by adding a finishing oil agent mainly containing

As Comparative Example 1, up to the bobbin 8 is the same as the embodiment, and the rollers 12, 14 and heaters 13, 15 shown in FIG.
A sewing machine yarn using a spun yarn-like polyester multifilament yarn which is not subjected to drawing and heat relaxation was manufactured.

The characteristics of Example 1 and Comparative Example 1 are summarized in Table 1. Tensile strength and stress at 7% elongation are JIS L-10
It carried out by the measuring method based on 13. The dry heat shrinkage is the same as JIS L-1013 dry heat shrinkage B method and the temperature is 1
It was carried out at 60 ° C. The sewability is determined by measuring the number of sewable sewn fabrics by using the lockstitch sewing machine for a length of 4 m and then stacking 4 twill woven fabrics with a buttonhole sewing machine.
The skipped stitches were evaluated at defective sewing points when the overlock stitching was performed, and two stitched twill fabrics were ironed on the seams after the main stitches, and the stitches were evaluated by pulling, nep or the like.

[0018]

[Table 1]

It has been found that the sewing thread of the present invention has a larger stress at 7% elongation corresponding to the tensile elastic modulus than the sewing thread of the comparative example, so that there is less skipping and the strength is increased so that a large number of sewable pieces can be obtained. It was In addition, since the shrinkage of the thread was reduced, the seams did not become pucker-like, and the appearance was very beautiful combined with the effect of fluff.

[0020]

According to the method for producing the sewing thread of the present invention,
It is possible to obtain a sewing thread which has a uniform appearance with little yarn unevenness in spite of the presence of fluff, and which has a high tensile elastic modulus and a low heat shrinkage, which is a characteristic that has not been obtained in the past. When the sewing thread obtained by the manufacturing method of the present invention is used, stitch skipping is small, the number of stitches that can be sewn is large, and thread breakage due to fusing during sewing is small, and sewing can be performed under good sewing conditions. You can get beautiful things.

[Brief description of drawings]

FIG. 1 is a side view of an apparatus for producing and plying a spun yarn-like polyester multifilament yarn according to the present invention.

FIG. 2 is a side view of an apparatus for subjecting a ply-twisted yarn of the present invention to additional twisting, hot drawing, and relaxation heat treatment.

[Explanation of symbols]

 1, 1 ', 1 "; polyester multifilament yarn 2, 2', 2"; rotary disk 3, 3 ', 3 "; tension device 4, 4', 4"; yarn raising device (application including rough surface) Twisted body) 5; Ralar device 7; Ring-type twisting machine 8; Ply-twisted bobbin 10; Additional-twisted ply-twisted yarn 12, 14, 16; Rollers 13, 15; Heater

Claims (7)

[Claims] 1. A plurality of spun yarn-like polyester multifilament yarns which have undergone undertwisting and in which a part of the multifilaments have been cut, are combined, A method for producing a sewing machine thread, which comprises subjecting a ply-twisted yarn to a ply-twist in the direction, and then subjecting the plied-twisted yarn to hot drawing and relaxation heat treatment. 2. The spun yarn-like polyester multifilament yarn according to claim 1, wherein after twisting the polyester multifilament yarn, a twisted body including a roughened surface is provided in a direction opposite to the above-mentioned twisting direction. 2. The method for producing a sewing thread according to claim 1, wherein the spun yarn-like polyester multifilament yarn obtained by a method in which a part of the multifilament is cut at the same time when the false twist is applied. 3. The method for producing a sewing thread according to claim 1, wherein a plurality of ply-twisted spun yarn-like polyester multi-filament yarns are twisted without being once wound. 4. The method for producing a sewing thread according to claim 1, wherein the ply-twisted yarn is subjected to hot drawing and relaxation heat treatment without being once wound after being twisted. 5. A spun yarn-like polyester multifilament yarn that has undergone an undertwisting process, is provided with a part of the number of upper twists set by combining a plurality of yarns without winding it up once, and then is wound up with a double twisting machine. 2. The method for producing a sewing thread according to claim 1, wherein the twisted yarn is subjected to hot drawing and relaxation heat treatment without being wound once after the set remaining number of twists is applied. 6. The method according to claim 1, wherein the drawing temperature is 80 ° C. to 230 ° C. and the drawing ratio is 1.02 to 1.25. 7. The relaxation heat treatment temperature is higher than the stretching temperature and 150 ° C. to 240 ° C., and the relaxation ratio during the heat treatment is 0.85 to 0.85.
The method for producing a sewing thread according to claim 1, wherein the sewing thread is in the range of 0.99.