JPH1025640A - Production of machine sewing thread - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart a uniform appearance and good sewing characteristics to a polyester multifilament machine sewing thread having fuzzes and hardly cause the thread breakage due to stitch skipping and melting and cutting off at the time of sewing. SOLUTION: This method for producing a machine sewing thread is to double plural spun yarnlike polyester multifilament yarns, undergoing the first twist and partially cutting the mulfilaments, apply the final twist thereto in the opposite direction to the first twist one of the spun yarnlike polyester multifilament yarns, provide a plied yarn and then hot-draw the plied yarn in the method for producing the polyester multifilament machine sewing thread. At this time, the hot-drawing is preferably carried out at a drawing temperature within the range of 80-230 deg.C and a draw ratio within the range of 1.02-1.20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sewing thread, and more particularly to a method for producing a sewing thread having the same uniformity as a filament sewing thread and having the same ease of handling as a spun thread. The present invention relates to a novel method for producing a sewing thread.

[0002]

2. Description of the Related Art Polyester spun yarn, which is generally used as a sewing thread, is often used when a fine and beautiful appearance is required because the seam stain caused by thread spots and the manufacturing cost increases greatly when the thread becomes thinner. Filament sewing threads are often used.

[0003] A filament sewing thread using a polyester multifilament thread generally has a high tensile modulus of elasticity, so that a seam defect called skipped stitches at the time of sewing is unlikely to occur, and the tensile strength is low. Since the fluctuation is small, thread breakage during sewing is also small. In addition, the filament sewing thread has a feature that it has few thread spots and beautiful stitches. However, when sewing at a high speed using a filament sewing thread, the sewing needle has a temperature often exceeding the melting temperature of the thread, so that there is a problem that the filament sewing thread is melted when stopped. Further, since the sewing thread has no fluff, there is no appropriate friction between the cloth and the thread, and a disadvantage that the seam floats from the cloth is likely to occur, which is another problem of the filament sewing thread.

Therefore, as a method of improving such a drawback of the filament sewing thread, Japanese Patent Application Laid-Open No. 50-82342 has been proposed.
JP-A-5-136947, JP-A-2-136947
No. 216233, a method of applying a scraping body or a grindstone to a polyester multifilament, a method of applying a entanglement treatment with a twisted yarn or a high-pressure air fluid, and then using a fluffed yarn by a method of rubbing its own yarns. Has been proposed.

[0005]

However, the yarn to which the fluff is applied by each of the above-described methods causes a minute fluctuation in the length of the yarn between the constituent multifilaments. The yarn has a low tensile modulus and does not always have good sewing properties.

The present invention has been found to address the above-mentioned actual situation, and to further provide a processing such as twisting and drawing to a sewing thread obtained by adding fluff to a polyester multifilament.
An object of the present invention is to provide a sewing thread having a uniform appearance, less skipping due to skipping and fusing during sewing, and having good sewing characteristics.

[0007]

That is, the feature of the present invention that meets the above-mentioned objects and solves the problems is as follows. First, basically, in the production of a polyester multifilament sewing thread,
A plurality of spun yarn-like polyester multifilament yarns that have been subjected to priming and a part of the multifilament has been cut are combined, and the plied yarn is twisted in a direction opposite to the direction of priming of the spun yarn-like polyester multifilament yarn. And then subjecting the plied yarn to hot drawing.

The invention according to claim 2 is a preferred embodiment of the spun yarn-like polyester multifilament yarn in the above-mentioned method, that is, a spun yarn-like polyester multifilament yarn in which sub-twisting is performed and a part of the multifilament is cut. A spun yarn obtained by subjecting a polyester multifilament yarn to priming and then applying a false twist in a direction opposite to the priming direction to a twisted body including a roughened body and simultaneously cutting a part of the multifilament It is to use a like thread.

According to a third aspect of the present invention, a plurality of spun yarn-like polyester multifilament filament yarns obtained by performing the above-mentioned twisting and cutting a part of the multifilaments are once wound together without winding and then twisted. It is characterized by the following.

[0010] Further, the invention according to claim 4 is that the ply-twisted yarn which has been combined and twisted is subjected to a hot-stretching step without winding once after being twisted, and then the twisted yarn is subjected to heat. It is characterized by being stretched.

According to a fifth aspect of the present invention, a change is made to the ply twist in the above method, and a plurality of the above-mentioned spun yarn-like polyester multifilament yarns are temporarily combined without being wound, and are set to this. It is characterized in that a part of the number of twists is applied and once wound, and then the remaining of the set number of upper twists is applied by a double twisting machine, and then the plied yarn is subjected to hot stretching without winding. As the conditions for the thermal stretching in the method described above, it is preferable to perform the thermal stretching at a stretching temperature of 80 to 230 ° C. and a stretching ratio of 1.02 to 1.20.

[0012]

Embodiments of the present invention will be described below in further detail.

[0013] As described above, the present invention starts from using a spun yarn-like polyester multifilament yarn in which priming is performed and a part of the multifilament is cut. The spun yarn-like polyester multifilament yarn in which the above-mentioned plying used in the present invention is applied and a part of the multifilament is cut is subjected to multifilament by a method such as running the filament by pressing the filament against a sharp material such as a cutting tool. Can be obtained by twisting the obtained yarn after cutting a part of the multifilament, but in general, the method of fluffing a part of the multifilament by such a method greatly reduces the strength and elongation of the yarn and the twisting property However, there is a possibility that yarn characteristics suitable for use of a sewing thread which is poor and requires strength may not be obtained.

Therefore, the spun yarn-like polyester multifilament yarn in the present invention 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 strength and is preferable for use in sewing threads.

[0015] Then, after the polyester multifilament is further twisted, a false twist in a direction opposite to the above-mentioned twisting direction is applied to the twisted body including the roughened body, and at the same time, a part of the multifilament is cut. FIG. 1 shows the outline of the method. An up twister method is preferred as a method for imparting a lower twist, and a double twist method is particularly preferred because the tension applied to the yarn during twisting is constant, the quality is high, and the productivity is high. Then, the polyester multifilaments 1, 1 'used as shown in the figure,
1 "is wound on a bobbin in advance 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. The twisted polyester multifilament is used as a guide G1,
G1 ', G1 ", tension devices 3, 3', 3", guides G2, G2 ', G2 ", and are guided to a twisted body 4 including a roughened body.
A false twist is performed in the opposite direction to the twist direction given at 2 ″, and a part of the polyester multifilament is easily cut on the twisted body 4 by the false twist in the reverse direction with a very small twist. Immediately after the yarn has passed through the twisted body 4, the priming provided by the rotary disks 2, 2 ', 2 "returns.

Thus, the spun yarn-like polyester multifilament yarn to which fluff has been imparted by cutting a part of the filaments can be once wound one by one, or can be wound once simultaneously. As shown in 1,
When a plurality of these are combined and wound around the bobbin 8 by the ring type twisting machine 7, the process can be shortened and it is reasonable. Usually, the number of twists is smaller than that of the lower twist by the reciprocal of the ratio of the square root of the fineness, but the ring type twisting machine of the upper twist can increase the rotation speed more than the double twisting machine of the lower twist. It is difficult, and in the ring-type twisting machine 7, it is preferable to give a twist number of about 30% to 80% of the twist number in setting. In addition, 5 is a take-up roller, G4 is a guide, and 6 is a snail wire.

Next, the twisted bobbin 8 is
The ply twisted yarn is mounted on a double twisting machine equipped with a heater as shown in FIG. 2, and the remaining twist number of the set twist number of the upper twist is given. Then, the plied yarn 10 to which the set twist number is given is drawn through the heater 13 between the rollers 12 and 14, and then wound around the package 16 by the winding roller 15.

In general, in a spun yarn-like polyester multifilament yarn subjected to priming, the orientation of fibers between the multifilaments is reduced at the stage of imparting fluff, and the tensile modulus of the yarn is reduced. The inventor has determined that this is the reason why the sewing property of the sewing thread using the spun yarn-like polyester multifilament yarn is not improved, and has further reached a method of hot drawing.

A method of independently hot-drawing a spun yarn-like polyester multifilament yarn having been subjected to priming can be considered, but the orientation is again disturbed at the stage of ply-twisting, and a sufficient effect is hardly obtained. On the other hand, a sufficient effect can be obtained only by hot-drawing a plurality of yarns used as sewing threads in a twisted state. Therefore, usually, the latter hot-stretching in the twisted state is applied.
It is preferable that the stretching ratio is 0 ° C. and the stretching ratio is in the range of 1.02 to 1.20. If the stretching temperature is lower than 80 ° C., the stretching is not performed uniformly, and the yarn structure does not have a uniform filling structure without unevenness. If the stretching temperature exceeds 230 ° C., the fibers are thermoset, leading 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. Stretch ratio is 1.2
Exceeding 0 is not preferable because the yarn breakage in the drawing step increases and the heat shrinkage of the plied yarn increases.

The thus obtained plied yarn of a spun yarn-like multifilament having a high fiber orientation in the yarn and having a fluff is a plied yarn dyed with moss or cheese,
A finishing oil which has an effect of reducing abrasion between the needle and the thread at the time of sewing is applied and wound on a pobin.

[0021]

EXAMPLES The apparatus shown in FIGS. 1 and 2 was used as follows. Polyester multifilament produced by ordinary spinning and drawing methods has a breaking strength of 5.2 g / denier, a breaking elongation of 30%, a heat shrinkage at 160 ° C. of dry heat of 5%, a fineness of 60 denier, and a filament. Number is 108
The polyester multifilament yarns 1, 1 ', 1 "are wound up in a pan using a normal pan winder, set in a holder (not shown), and the rotary discs 2 to 2" are rotated in the twisting direction Z in 1250 times /
After twisting of m, a tension of 6 grams was applied by a tension device 3 to 3 ″, and the yarn was guided to the twisted body 4 for raising the yarn. The twisted body 4 was disclosed in JP-A-4-240237. A circumscribed twisted body having a surface roughness of 20 s and having three rough disks mounted thereon was used, and twisting in the false twist direction S was given by the twisted bodies 4 to 4 ″. While cutting a part of the multifilament constituting the polyester multifilament, the three filaments were put together by a roller 5 and guided to a ring type twisting machine 7, twisted in the S direction at 500 times / m, and wound up on a bobbin 8.

Next, the bobbin 8 is subjected to 400 twists / m in the S direction using the apparatus shown in FIG.
Stretch ratio 1.08 between rollers 12 and 14, temperature 200
The twisted yarn 10 was stretched at a temperature of ° C. and wound up into a package 16. Incidentally, the stretching ratio was determined by the following equation. Stretching ratio = surface speed of roller 14 / surface speed of roller 12 The plied yarn wound up in the package 16 is wound up into a soft-wound cheese, dyed at 130 ° C., and a finishing oil agent mainly composed of silicon is applied thereto to give a sewing machine according to the present invention. The thread was obtained.

On the other hand, as a comparative example, the drawing up to the bobbin 8 is the same as that of the above-described embodiment, and the drawing is not performed without using the roller 14 and the heater 13 in FIG. 2 (the twisted yarn is not nipped by the roller 12. (Room temperature) A sewing thread using a spun yarn-like polyester multifilament yarn was produced.

Therefore, Table 1 summarizes the characteristics of these Examples and Comparative Examples. In addition, the tensile strength and the stress at the time of 7% elongation were implemented by the measuring method based on JIS L-1013. Dry heat shrinkage is also JIS L-1013
Was conducted at a temperature of 160 ° C. by the dry heat shrinkage B method. The sewing performance was measured by using a lockstitch sewing machine to measure the number of sewable pieces by measuring how many pieces of twill fabric could be sewn for 4 m, and performing four times of overlocking with four button cloths. Evaluate stitch skipping at the time of poor sewing, and the seam is ironed to the seam after the main sewing of two twill fabrics,
Evaluation was made with a cramp and a nep.

[0025]

[Table 1]

From Table 1 above, the sewing thread of the present invention has a larger stress at 7% elongation corresponding to the tensile elasticity and has less stitch skipping and a higher strength than the sewing thread of the comparative example. It turns out that we can get a lot. Further, since the shrinkage of the thread was low, the seam did not become puckering, and the appearance was very beautiful in combination with the effect of fluff.

[0027]

As described above, in the method for producing a sewing thread of the present invention, a plurality of spun yarn-like polyester multifilament yarns which have been subjected to a bottom twist and a part of the multifilament has been cut are joined together. After twisting in the opposite direction to form a ply-twisted yarn, the twisted yarn is subjected to hot drawing.In particular, the ply-twisted polyester multi-filament yarn is twisted in a direction opposite to the ply-twisting direction. Since the yarn is ply-twisted and subjected to thermal drawing, a sewing machine yarn having an unprecedented characteristic that has a uniform appearance with few yarn spots, a high tensile elastic modulus, and a low heat shrinkage, despite the presence of fluff, is obtained. Moreover, the use of the sewing thread obtained by the production method of the present invention reduces the number of skips,
Sewing can be performed under good sewing conditions such as a large number of sewable sheets and a small number of thread breaks due to fusing at the time of sewing, and a beautiful seam with a sewing twist can be obtained. In particular, the use of the spun yarn-like polyester multifilament yarn according to claim 2 reduces the strength of the yarn little and enhances the practical effect of the sewing thread. In addition, multiple strands can be twisted together and stretched by heat to shorten the process and contribute to streamlining the process, while using a double twisting machine to increase twisting efficiency and improve productivity. Has the effect of causing.

[Brief description of the drawings]

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

FIG. 2 is a side view of an apparatus for subjecting a twisted yarn to additional twisting and hot stretching according to the present invention.

[Explanation of symbols]

 1, 1 ', 1 "polyester multifilament yarn 2, 2', 2" rotary disk 3, 3 ', 3 "tension device 4, 4', 4" twisted body including roughened body 5 roller 7 ring type twisted yarn Machine 8 Twisted bobbin 10 Twisted twisted yarn 12, 14 Roller 13 Heater 15 Winding roller 16 Package

Claims (6)

[Claims] 1. A spun yarn-like polyester multifilament yarn which is subjected to priming and part of a multifilament is cut, and a plurality of spun yarn-like polyester multifilament yarns are combined with each other in a direction opposite to the priming direction of the spun yarn-like polyester multifilament yarn. A method for producing a sewing thread, comprising: twisting in the direction of (1) to form a plied yarn, and then subjecting the plied yarn to hot drawing. 2. After the polyester multifilament yarn is subjected to priming as the above-mentioned spun yarn-like polyester multifilament yarn, the twisted body including the roughened body has a temporary twist in a direction opposite to the priming direction. 2. The method for producing a sewing thread according to claim 1, wherein a spun yarn-like polyester multifilament yarn obtained by cutting a part of the multifilament while applying twist is used. 3. The sewing thread according to claim 1, wherein a plurality of spun yarn-like polyester multifilament yarns, which have been subjected to priming and part of the multifilaments have been cut, are combined without being once wound, and then twisted. Manufacturing method. 4. The method for producing a sewing thread according to claim 1, wherein after the first twisting is performed, the twisted yarn is subjected to hot drawing without being once wound. 5. A spun yarn-like polyester multifilament yarn which has been subjected to priming and a part of the multifilament has been cut, and is then wound together without being wound up once, and a part of the set number of twists is given to the yarn. 2. The method for producing a sewing thread according to claim 1, wherein the winding is performed, followed by applying the remainder of the set number of twists by a double twisting machine, and then stretching the plied yarn without winding. 6. The hot stretching is performed at a stretching temperature of 80 ° C. to 230 ° C.
The method for producing a sewing thread according to any one of claims 1 to 5, wherein the stretching ratio is set in a range of 1.02 to 1.20.