JPS5940932B2 - polyester sewing thread - Google Patents

Description

[Detailed description of the invention] [Technical field of the present invention] The present invention relates to polyester threads.

More specifically, it is composed of one or more single yarns made of polyester multifilament fibers having false twist crimp, and the constituent filaments are not intertwined with each other along the yarn axis. The basic structure is a so-called intermittent intertwined structure in which thread portions and intertwined thread portions are alternately formed, and it relates to a novel polyester sewing thread that has been further improved under this basic structure. .

[Prior art and its problems]

Various kinds of sewing threads have been known in the past, and sewing threads made of spun threads and threads made of false twisted threads are most notable, and these threads have various defects.

For example, spun yarn inherently has uneven thickness, which causes large fluctuations in yarn strength, resulting in defects such as thread breakage during sewing and the beauty of sewn products.

On the other hand, false twisted yarn tends to be inferior in sewability to spun yarn for some reason, and it is generally said that it is better for the yarn to have fluff.

From this point of view, there have been many attempts to form fluff or fluff-like protruding fibers in filament fiber sewing threads, but at present there are few that satisfy the properties required for sewing threads.

On the other hand, techniques for imparting fluff to multifilament yarns are well known, but they can weaken all or part of the fibers by using weak fibers, scratching them with an abrasion material, or making them thermally embrittled. It is made by cutting and making fluff,
Since the fluff is long and weakly formed, it has the disadvantage of making it difficult to pass through the sewing machine process.

For example, as a technology for processed yarn with the above-mentioned fuzz, JP-A-5
The present inventors have already proposed Publication No. 3-6658,
Although it is possible to use such a fluffed yarn as a sewing thread, since such a fluffed yarn has cut fiber ends, it has the disadvantage that fluff and neps tend to accumulate in the hole of a sewing machine needle.

A known example of further improving dimensional stability is JP-A-52-6.
No. 3,454 is available, but this technique does not rely on false twist yarns, and the filaments have no protruding ends, resulting in poor sewability.

Furthermore, in the prior art ζ such as the above-mentioned known examples, no measures were taken to reduce the swirling force of the yarn, so the yarn strength was still poor.

[Object of the present invention]

In view of the above-mentioned deficiencies of the conventional technology, the present inventors conducted intensive research and as a result, they came to provide a polyester sewing thread according to the present invention.

That is, the present invention, when forming a sewing thread with a filament false twisted thread, forms a fiber protrusion having no fiber cut ends, and also firmly fixes the fiber protrusion to the yarn shaft, and also reduces the number of torque twists. The purpose is to simultaneously improve heat resistance stability, improve sewing performance as a whole, and improve the quality of sewn products.

[Configuration of the present invention]

The present invention has the following configuration.

A sewing thread consisting of one or more single yarns made of polyester multifilament fibers, the single yarn being a false twisted yarn, and a yarn portion in which the constituent filament fibers are intertwined with each other along the yarn axis. All filament fibers that have alternating unentangled yarn portions and protruding filament fiber portions with no cut ends that protrude from the yarn axis, and that constitute the single yarn. are of substantially equal length, the number of twist twists under the following conditions is 10 times/m or less, and the dry heat shrinkage rate (180 ° C.
A polyester sewing thread characterized by having a content of 2% or less (x30 minutes).

(However, to determine the number of torque twists, take a sample yarn (1 m), hang a small load (2 mg/D) in the center, align both ends of the yarn, fold it in half, and read the number of rotations of the small load. , the unit is times/m.

) Hereinafter, the polyester sewing thread of the present invention will be explained in more detail.

The sewing thread of the present invention is formed by one or more single threads made of polyester multifilament fibers having false twist crimp.

The constituent single yarns have intermittent intertwined portions,
It has filament fiber parts protruding from the yarn axis everywhere.

This protruding filament fiber portion is not formed by cutting the filament end by end, but is formed as a part of the continuous filament, and due to the above-mentioned intermittent entanglement ζ, it is difficult to move around in the system. It is fixed so that it does not.

In the present invention, one single yarn refers to one yarn made of multifilament fibers, and multiple yarns refer to two or three yarns.
Refers to child twisted yarn, etc.

That is, even if there is only one single filament, there are many fibers constituting it, so that the above-mentioned intertwined form is formed.

In the polyester sewing thread of the present invention, the dry heat shrinkage rate (1
80°C for 30 minutes) is 2% or less.

If the dry heat shrinkage rate exceeds 2%, the thread will shrink due to heat generated during the sewing process or during heat setting of the sewn product, making it undesirable as a winding thread.

Furthermore, the sewing thread of the present invention (in which the constituent single threads are such that all of the constituent filament fibers have substantially the same length).

By doing this, in addition to the effect of intermittent entanglement, it is possible to almost eliminate the aforementioned protruding filament fiber portion from sliding due to external force such as squeezing action, thereby preventing the occurrence of neps, etc. There are few
Moreover, the strength utilization rate of the constituent filaments is extremely high even as a sewing thread.

In this regard, for example, in a yarn in which the constituent single yarn is formed from two multifilament yarns, one of which is overfeed, and the protruding filament fiber portion is formed by the fibers on the overfeed side, the protruding filament fiber portion is It tends to move and form neps, and the strength utilization rate of the constituent filaments is also very low, which is completely undesirable.

Next, in the present invention, it is necessary that the number of torque twists is 10 or less.

False twisted yarn (yarn with a small number of false twists) usually has torque, but
When the torque is high, an inconvenient phenomenon occurs in which the threads become twisted or tangled during sewing.

If such a phenomenon occurs, satisfactory sewability cannot be obtained.

Therefore, it is important to set the torque twist number as small as possible to eliminate the turning force of the yarn itself.

If the number of torque twists is 10 times/m or less, the sewability will be satisfactory.

The polyester sewing thread of the present invention preferably formed is (
Even if the test (Ig/l) tension application - tension removal) was repeated 10 times, the elongation rate with respect to the yarn length before the test (before the test) was an extremely small value of 2% or less. This confirms that the protruding filament fiber portions are bound and fixed in a strong ζ-core system, and also supports the fact that the fibers themselves are hard to induce plastic deformation.

The fact that the sewing thread has a small elongation rate with respect to tension and is extremely dimensionally stable improves sewability and improves the beauty of sewn products.

On the other hand, the polyester sewing thread of the present invention, which is formed more desirably, has a dry heat shrinkage rate (180°C x 30 minutes) of (
%) and the elongation rate (%) with respect to the yarn length after repeating (Ig/D tension application - tension removal) 10 times, it shows a value of 3% or less, This creates an extremely excellent sewing thread that is stable against heat and tension.

The polyester sewing thread of the present invention has the above-mentioned structure and has high strength, generally 4 g/D or more, and 5 to 6 g/D using a polymer with high intrinsic viscosity.
It is also fully possible to achieve a strength as high as /D or higher.

In the polyester sewing thread of the present invention, the false twist crimp of the filament fibers reduces the coefficient of friction against metals such as binding needles and guides, and improves sewability. On the other hand, the protruding filament fiber portions give the sewing thread of the present invention, which is made of filaments, a spun yarn-like appearance and performance. It has both the advantages of a sewing thread made of spun yarn and the advantages of a sewing thread made of false twisted yarn.

According to the findings of the present inventors, it seems preferable to have 200 or more protruding filament fibers per meter of yarn in terms of the above-mentioned effects of the present invention, and the protruding filament fibers are , present in the thread in one type of shape such as an arcuate, annular or twisted shape, or in a mixture of multiple types.

The method for manufacturing the single yarn constituting the polyester sewing thread of the present invention includes, for example, subjecting polyester multifilament yarn to false twisting or stretching false twisting, and then processing it in a fluid jet entangling device having an intermittent entangling action. After that, it is heat set.

The protruding filament fiber portion is mainly relaxed after the false twisting or stretching false twisting, and is conveniently fed to a fluid jet entangling device with a high overfeed to form a relaxed state upstream of the fluid jet entangling device. Therefore, the protruding filament fiber portion is formed from the filament itself by the crimping force of the filament, and the protruding filament fiber portion is then bound and fixed through the intermittent entangling treatment described above.

Therefore, even though the single threads constituting the sewing thread of the present invention have protruding filament fiber portions, all the constituent filament fibers are essentially of the same length. be.

The crimp force of the filaments forming this protruding filament fiber portion depends on the conditions of the false twisting force, but is mainly influenced by the number of false twists.

If the number of false twists is small, the crimp becomes large and a large protruding filament fiber portion is formed, but at the same time the crimp force is weakened, and if the number of false twists is even smaller, hardly any protruding filament fiber portions are formed.

On the other hand, when the number of false twists is large, the crimp force becomes stronger, but the crimp becomes finer, and the protruding filament fiber portions are formed finely, and in the end, no protruding filament fiber portions are formed at all. The number of false twists applied will generally fall within a range that does not result in the formation of protruding filament fibers.

According to the findings of the present inventors, the range of the false twist number and relaxation rate that preferably forms the protruding filament fiber portion seems to be the range expressed by the following formula, where D is the polyester to be false twisted. denier number of the filament yarn, ρ is the specific gravity of the fiber, T is the number of false twists per ml of yarn, ■2 is the take-up speed of the false twisting process, and ■3 is the take-off speed of the entangling process.

Furthermore, in the above process, after false twisting, before fluid treatment,
It is also possible to apply tension to the yarn by drafting it at an appropriate point such as during the middle or after the process, and by applying such tension, it is possible to adjust the number, size, etc. of the protruding filament fiber portions.

For example, when tension is applied once after false twisting and before relaxation, the number of protruding filament fiber portions formed is:
It is possible to make them more numerous and finer than in the case where the tension is not applied.

In addition, if the yarn is subjected to a draft action during or immediately after the fluid entanglement treatment, the weaker protruding filament fiber portions will disappear and the stronger ones will be selected and remain, especially those with high tensile strength. It can be made into a highly durable sewing thread.

The above-mentioned false-twisting strength is mainly due to the fact that the number of false twists is lower than that of normal false-twisting, and also by appropriately selecting other conditions such as the false-twisting temperature, etc. It is relatively easy to process a material with high strength, low elongation, and low heat shrinkage, and it can also be said that this process is most suitable for sewing thread.

Furthermore, the number of twists and torque can be made extremely low due to the heat setting after the entangling treatment.

As mentioned above, the single threads constituting the sewing thread of the present invention are manufactured by false twisting or drawing false twisting polyester multifilament threads, followed by interlacing treatment, and in many cases, they are processed into the desired sewing thread shape with an appropriate number of threads, Furthermore, the sewing thread is subjected to reheating processing and/or heat setting processing such as dyeing power Loe, but for example, when one sewing thread is made, the turning property imparted during the false twisting remains, resulting in Q. If snarling occurs and sewing is difficult, first combine the S-direction false-twisted yarn and the Z-direction false-twisted yarn and then perform the interlacing process to make the yarn substantially free of swirling properties. Good too.

In addition, when the sewing thread is to be used as a twin or triple thread, a single thread with substantially no turning ability as described above may be used, or the first twist and the second twist may be used as a single thread. It is preferable to twist the yarn so that it is substantially balanced to form a sewing thread.

[Effects of the present invention]

In the sewing thread of the present invention, the fibers protruding from the thread axis are formed of arcuate, annular, or twisted portions of constituent filament fibers with no cut ends, so they have favorable frictional properties and excellent sewing properties. good.

In other words, if there is a cut end, fuzz tends to accumulate, but this can be prevented.

Further, since the protruding portions of the yarn shafts are strongly fixed to the entangled yarn shafts, they can be prevented from being pulled out.

Since the filament fibers constituting the appellant have substantially the same length, there is no possibility that some fibers will be left over and become a yarn pool.

Moreover, since it has an intermittent intertwining structure, it not only has bulk and softness, but also tends to flatten when using single thread without twisting, so overlock stitching is optimal.

Furthermore, in the present invention, since the number of torque twists of the thread is 10 times/m or less, the thread does not get tangled or twisted during sewing, and stable sewing can be performed.

In addition, since the dry heat shrinkage rate is low, the shape does not change even after dyeing or ironing, and the quality is good even in stitches where the sewn part is exposed on the outside.

Examples will be described below.

Example 1 Multifilament yarn of polyethylene terephthalate (
70 denier - 24 filament) at 190℃, 15
00 T/m false twisting, then 14% relaxation and fluid injection intermittent entangling device ζ trowel entangling, then 22
Heat setting was performed at 0°C.

The obtained yarn was made into a single yarn and triple-twisted yarn (lower twist S900 T/
(m, ply twisted Z600T/m) was made, and then cheese dyed at 130°C to obtain a sewing thread.

When this sewing thread was investigated, the dry heat shrinkage rate (180°C x 30 minutes) was 1.1%, the number of torque twists was 5.0 times/ms, and the process of applying tension at 1 g/D and removing the tension was repeated 10 times. The elongation rate after that is 0.5% and the strength is 4.2g/d.

The number of protruding filaments without cut ends was 250 filaments/m, and the sewability was extremely good, making it an excellent sewing thread.

Example 2 In Example 2, the heat setting after the entangling treatment was set at 210°C.
The sewing thread was made under the same conditions except that the same conditions were used.

The dry heat shrinkage rate of this sewing thread is 1.8%, and the torque twist number is 9.5.
times/m, and the number of protruding filaments without cut ends was 260/m.

This sewing thread also had good sewability and excellent seam quality.

Comparative Example 1 Polyethylene terephthalate was melt-spun and
A multifilament yarn with a thickness of 130 denier and 36 filaments was produced by pulling it out at a speed of 1 min.

Next, a fluffy yarn was made by referring to the example of JP-A No. 53-6658.

That is, the above yarn was stretched 1.50 times at 500 m/rnin while being in contact with a hot plate having a length of 30 crrL at 150°C.

Next, this drawn yarn was false-twisted 2800 times/m at a heating temperature of 23
Temporary twisting was performed using a spindle at 0°C and under 10% elongation.

Then 4.0 kg/crI from a hole with a hole diameter of 0.8 mm
Compressed air of tG was injected from the side (at an angle of 90° to the yarn) of the false twisted yarn running at 200 m/min to obtain a yarn with fluffy ends.

This single yarn was twisted into triple twists in the same manner as in Example 1, and its sewability was tested.

As a result, the sewing machine needle hole and other moving parts were clogged with fluff and thread breakage, resulting in extremely low sewing efficiency.

The strength of this yarn was 2.0 g/d, and the number of twist twists was 28 turns/m.

Claims (1)

[Scope of Claims] 1. A sewing thread composed of one or more single threads composed of polyester multifilament fibers, the single threads being false twisted threads, the constituent filament fibers intertwine along the thread axis. has intertwined thread portions and unentangled thread portions alternately, and has protruding filament fiber portions with no cut ends protruding from the yarn axis, and constitutes the single yarn. All of the filament fibers are of substantially the same length, and furthermore, the torque twist number under the following conditions is 10 times/m or less, and the drying shrinkage rate (18
0° CX 30 minutes) is 2% or less. (However, the number of torque twists: Take the test drug (1 m), hang a small load (2 mg/D) in the center, align both ends of the thread, fold it in half, and read the number of turns of the small load. The unit is times/m.)2 The polyester sewing thread according to claim 1, characterized in that there are 200 or more protruding filament fiber portions without cut ends per thread Im.