JPH0465545A - Heat-resistant high strength sewing yarn - Google Patents

Abstract

PURPOSE:TO provide the subject yarn enabling sewing operations under high tensions by twisting plural aromatic polyamide fibers having a high strength and a low elongation with each other and subsequently thermally fusing a hot-adhesive filament at an approximately center portion of the sewing yarn to bond the polyamide fibers to each other. CONSTITUTION:Plural aromatic polyamide fibers having a high strength and a low elongation (e.g. comprising a polycondensation product of p-phenylene diamine with isophthaloyl chloride) are twisted with each other and a hot adhesive filament (preferable a polyamide copolymer) blended in the approximately center portion of the sewing yarn is melted to bond the aromatic polyamide fibers to each other for the preparation of the objective yarn. The objective yarn is preferably obtained by subjecting the aromatic polyamide fibers to the first twisting treatment, disposing the hot adhesive filament at the approximately center portion of the first twisted yarn 1, subjecting the yarn to the second twisting treatment and subsequently heating the prepared sewing yarn to melt the hot-adhesive filament.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sewing thread that allows sewing under high tension.

(Prior Art) Traditionally, sewing threads have mostly been made of natural fibers such as cotton and silk, but in recent years, synthetic fibers such as nylon and polyester have become mainstream. To use these fibers for sewing thread, there are usually methods such as twisting them or coating them with resin.

However, these natural fiber and synthetic fiber sewing threads have poor heat resistance9 and require high speeds when sewn with a sewing machine, etc.

It also has the disadvantage that when handled under high tension, frictional heat will be generated between it and the sewing machine needle hole, leading to thread breakage.

It could not be used for sewn products that require heat resistance.

Furthermore, in order to handle sewing that requires high seam strength, the sewing thread must be made thicker, making the sewing work laborious and increasing the amount of sewing thread used, which is also economically disadvantageous.

A fiber for sewing thread that solves these problems.

Aromatic polyamide fibers are considered, but aromatic polyamides have a single, rigid molecular structure in the fiber axis direction, and therefore have almost no elongation.

When processed into sewing thread using methods such as twisting or resin coating like normal sewing thread, it becomes fluffy, cannot maintain sufficient strength, and has low elongation, making it difficult to obtain sufficient mutual bonding between fibers. do not have. on the other hand.

In order to obtain mutual bonding between fibers by resin coating or the like, it is necessary to impregnate a large amount of resin, and as a result, the texture of the sewing thread becomes hard, making it difficult to use. and,
Sewing threads that fully utilize the characteristics of aromatic polyamide fibers are
The current situation is that it has not been developed yet.

(Problems to be Solved by the Invention) The present invention was made in view of the current situation, and aims to obtain a sewing thread that can be sewn under high tension using aromatic polyamide fibers. It is something to do.

(Means for Solving the Problems) The present invention achieves the above-mentioned purpose and has the following configuration.

That is, one aspect of the present invention is a sewing thread formed by twisting a plurality of high-strength, low-elongation aromatic polyamide fiber threads, in which the aromatic polyamide fiber threads have f! The gist of the present invention is a heat-resistant, high-strength sewing thread characterized in that it is made of heat-adhesive filament threads that are bonded to each other by heat melting near the center of the thread.

The present invention will be explained in detail below.

The suture of the present invention can be manufactured by the following method.

First, a high-strength, low-elongation aromatic polyamide fiber yarn is twisted as a normal sewing thread. The aromatic polyamide fiber system referred to here has a rigid structure such as an aromatic ring or a thiazole ring in the main chain of a 9-molecule structure. I can pick up a thread. Moreover, high strength and low elongation mean 2 strength of 20 g/d or more and cutting elongation of 4% or less. Aromatic polyamide fiber yarns have a rigid molecular structure, so if a normal contact type snail guide is used during twisting, care must be taken as the pulling tension will cause fuzzing, which will lead to a decrease in strength. As a countermeasure for this.

The above problem can be solved by using a rotary bearing guide as the guide.

Next, the plurality of first-twisted aromatic polyamide fiber yarns are put together and the second twist is applied. Twist together.

This will be explained using drawings as follows.

FIG. 1 is a schematic diagram illustrating a thread twisting machine used in manufacturing a heat-resistant, high-strength sewing thread according to the present invention.

The second figure is an enlarged view of the twisting guide used in the final twisting process, and FIG. 3 is a cross-sectional view of the sewing thread of the present invention. Aromatic polyamide fiber yarn pre-twisted to an arbitrary twist using a rotary bearing guide 1. 1. 1.

Each of the pieces is passed through a nip roller 3, guided to each slit hole 4a of a twisting guide 4, and twisted and wound onto a winding bobbin 6 via a traveler 5. At this time, the heat-adhesive filament yarn 2 is directly passed through the slit hole 4b of the twisting guide 4 without passing through the nip roller 3, and is then wound onto the winding bobbin 6 together with the aromatic polyamide fiber yarn 1. At this time.

The tension of the thermoadhesive filament yarn 2 to be fed into the twisting guide 4 must be 115 times higher than the tension of the aromatic polyamide fiber yarn 1. If the feeding tension is less than 115, when the aromatic polyamide fiber yarns 1 are twisted together, the thermoadhesive filament yarn 2 enters in a meandering manner and is not placed in the middle between the aromatic polyamide fiber yarns 1.1°1. , even by the heat treatment described below, the fiber yarns cannot be bonded to each other. Heat-adhesive filament yarn 2 is mixed with aromatic polyamide fiber yarn 1,1゜1
In order to arrange it in the middle between them, the tension to be fed as described above and the slit holes 4a, 4b of the twisting guide 4 shown in FIG.
placement is important. The slit hole 4b through which the heat-adhesive filament yarn 2 is passed is located at the center of each slit hole 4a through which the aromatic polyamide m-fiber yarn 1 is passed, and each slit hole 4a is equally divided. In addition, the size of the slit holes 4a and 4b is such that the aromatic polyamide fiber yarns 1, 1.1 and the thermoadhesive filament yarn 2 that pass through the slit holes 4a and 4b are
You can adjust it depending on the thickness of the thread. By using such a twisting guide 4 and adjusting the tension that feeds the heat-adhesive filament yarn 2 to the twisting guide 4, the heat-adhesive filament yarn 2 is transferred to the aromatic polyamide fiber yarn 1. ．． 1.
It can be placed in the middle between 1.

The heat-adhesive filament yarn used here.

It is made of a hot melt resin that can be produced into filaments by melt spinning. For example, for aromatic polyamide fiber yarns, polyamide copolymer resins and polyurethane resins are preferable because they have high affinity for the fibers.

The twisting blend ratio of the thermoadhesive filament yarn to the aromatic polyamide fiber yarn may be selected in the range of 1 to 30%, but if it is in the range of 3 to 20%, particularly excellent adhesiveness and texture can be obtained. It is preferable because Also, by using the above mixing ratio,! ! When used as yarn, sufficient adhesion can be obtained to prevent fuzzing and maintain mutual bonding between fibers. When the twisting blend ratio is less than 1%, there is a drawback that the adhesive strength is poor and cannot withstand sewing under high tension, resulting in fuzzing. On the other hand, if it is 30% or more, although sufficient adhesion and anti-fluffing effects can be obtained, the texture becomes too hard, making it difficult to use, and it is also disadvantageous in terms of cost, which is not preferable.

In the present invention, the sewing thread obtained as described above is then subjected to heat treatment to melt the heat bonding filament thread 2 and bond the aromatic polyamide fiber threads 1.1.1 to each other.

The heat treatment can be carried out by conventional dry heat continuous treatment or steam setting. In addition, aromatic polyamide fiber threads generally have poor light resistance and abrasion resistance, so depending on the purpose of the sewing thread, resin or light stabilizer may be used during continuous dry heat treatment to thermally bond the non-adhesive filament threads. If the surface of the sewing thread is coated at the same time, a better effect can be obtained.

(Function) As in the heat-resistant, high-strength sewing thread of the present invention, heat-adhesive filament threads are placed in the middle between aromatic polyamide fiber threads and bonded to each other by heat melting.

It is possible to eliminate twist movement, so-called torque reproduction,
Moreover, the fiber threads are bonded to each other.

This helps prevent fuzzing during sewing and maintains strength, and as a result, the sewing thread of the present invention can be sewn under high tension.

(Example) The present invention will be explained below with reference to an example. The performance of the sample in the example was measured and evaluated by the following method.

(1) Creating the blend ratio of heat-adhesive filament yarn Based on the fineness of heat-adhesive filament yarn with respect to the sewing thread fineness, the percentage (
%).

(2) Adhesive The created sewing thread that had been subjected to strong thermal adhesive treatment was untwisted by 5 cm in advance, and then tested using a self-recording tensile tester.

Adhesive strength (g) was measured under conditions of a gripping interval of 5 cm and a tensile speed of 10 cm/min.

(3) Sewing strength The thread strength (kg) of the prepared sewing thread was measured using a self-recording tensile tester under conditions of a sample length of 25 cm and a tensile speed of 10 cm/min.

(4) Thread breakage tension 1 width 48.8 mm using a single needle lockstitch top and bottom feed sewing machine,
Thickness 1.15mm, weave density 172 threads/inch, weft 18.5
The number of revolutions of the sewing machine is 35 with two seat belts stacked on top of each other.
The maximum thread breakage tension when sewing was performed at 00 stitches/min and 12 stitches/10 cm was evaluated using a Checkmaster tension meter manufactured by Marizen Benkoki.

Example 1 A rotary bearing guide was attached to an ordinary ring twisting machine, and aramid fiber 375d/25Of (manufactured by Arami, Netherlands, trade name: Twaron) was twisted in the S direction by 300 T/25.
M twisting was performed to obtain a pre-twisted yarn. next.

The three pre-twisted yarns were each passed through a nip roller and guided to each slit hole of the twisting guide. On the other hand, one heat-adhesive filament 50d/7f (manufactured by Unitika ■, product name: Flor M) made of polyamide copolymer resin with a dry heat melting temperature of 100°C is twisted directly into the slit hole 4b of the guide 4 without using a nip roller. The yarn was twisted at 158 T/M in two directions together with the three pre-twisted aramid fibers to obtain a thread for sewing thread. At this time, the tension applied to feed the thermoadhesive filament to the twisting guide with respect to the aramid fiber lower twisted yarn was 1/3. 9 at 160℃ on this thread for sewing thread.
Continuous dry heat treatment was performed for 0 seconds.

Winding and fusing processing was performed at a speed of 20 m/min.

A sewing thread of the present invention was obtained.

For comparison with the present invention, the thermoadhesive filament used in the example was not used, the yarn was twisted using a normal snail guide instead of the twisting guide 4, and the continuous dry heat treatment was not performed. A comparative sewing thread was obtained under exactly the same conditions as in the example.

The performance of the sewing thread of the present invention and the comparative thread was measured, and the results are shown in Table 1.

Chapter 1 Table As is clear from Table 1, the sewing thread of the present invention is:

The sewing thread strength was increased by about 31% compared to the sewing thread of the comparative example, and the thread breakage tension was also about 38% higher, and it was able to withstand sewing under high tension.

(Effects of the Invention) The sewing thread of the present invention is characterized in that twisted aromatic polyamide fiber threads are interconnected by heat-adhesive filament threads near the center of the thread, which reproduces twist movement, so-called torque. Since this does not occur and the fiber threads are bonded to each other, it prevents fuzzing during sewing and maintains strength.

The sewing thread of the present invention can exhibit an excellent effect without deteriorating the sewing properties even when sewing with high tension.

[Brief explanation of drawings]

Figure 1 is a schematic diagram illustrating a twisting machine for manufacturing the sewing thread of the present invention, Figure 2 is an enlarged view of the twisting guide used in the twisting process, and Figure 3 is an enlarged view of the sewing thread of the present invention. FIG. 1 ゛ Aromatic polyamide F fiber yarn 2 after first twisting
Thermal adhesive filament yarn 3 Nip roller 4 Twisting guides 4a, 4b Slit hole 5 Traveler 6 Winding bobbin

Claims (1)

[Claims] (1) A sewing thread made by twisting a plurality of high-strength, low-elongation aromatic polyamide fiber threads, in which the aromatic polyamide fibers are bonded together by thermal melting of heat-adhesive filament threads near the center of the thread. A heat-resistant, high-strength sewing thread characterized by being bonded together.