JPS6392744A - Production of sewing yarn - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing sewing thread. More specifically, the present invention relates to a method for producing sewing thread suitable for sewing at high speed and under high tension.

[Prior art and its problems]

In recent years, synthetic fibers such as nylon and polyester have become the mainstream for sewing threads, instead of conventional natural fibers such as cotton and silk. but,
Filament sewing threads made of long synthetic fibers have the disadvantage that they cannot withstand high-speed, high-tension sewing. The reason for this is that when the sewing machine needle moves up and down with the sewing thread on the fabric to be sewn, the filament sewing thread has a large frictional force with the sewing machine needle, and therefore generates a large amount of frictional heat, causing the thread to melt and break. .

On the other hand, spun sewing thread made of short synthetic fibers has the advantage of being less likely to melt due to its low friction with the fabric, but has drawbacks such as uneven strength in the longitudinal direction of the thread.

In order to compensate for the shortcomings of each of the above three methods, core spun yarn has been proposed in which a long fiber is used as the core yarn and short fibers are entwined around it, but the strength has not been improved to the extent that it corresponds to the increase in cost. . In order to improve this, a conventional method for manufacturing bulky entangled yarn using jet flow was developed, for example, in Japanese Patent Application Laid-open No. 5
Proposals such as Japanese Patent No. 1-136947 have been made. Sewing threads produced by these methods are obtained by subjecting multifilament yarns made of synthetic fibers to bulky entangling treatment, then raising the surface layer by rubbing, and then twisting the yarns to obtain sewing threads.

The sewing thread obtained by this method has fluff that does not pull out, move or increase around the twisted yarn with high binding properties, so it has higher strength than spun yarn or core spun yarn, and has no neps. Since the strips have good uniformity, they are suitable for high-speed sewing. However, the sewing threads produced by these methods have a problem in that when high-tension sewing or thick fabric sewing is performed, cut threads are generated due to twisting and the like, resulting in insufficient sewability.

[Problem that the invention seeks to solve]

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a non-twisted sewing thread that has high abrasion resistance and heat resistance and is suitable for high-speed, high-tension sewing, or thick fabric sewing. .

[Means to solve the problem]

In order to solve the above problems, the method for producing sewing thread of the present invention involves simultaneously entangling filaments made of synthetic fibers constituting the core yarn and filaments made of synthetic fibers constituting the sheath yarn, and then heat-setting. The method is characterized in that the sheath filaments are overfed relative to the core filaments.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of an apparatus used in the present invention.

In the method of the present invention, filament A constituting the core yarn
The intertwining process between the sheath yarn and the filament B constituting the sheath yarn can be carried out by injecting an air jet stream using an air jet nozzle used in the manufacture of known loop intertwined yarns. During the entangling process, processing conditions such as air pressure, feed rate, heat setting, nozzle shape, etc. are adjusted so that loop entanglement is strong and hot water shrinkage rate is low.

In FIG. 1, core yarn filaments A are introduced to a first supply roller 1, and sheath yarn filaments B are introduced to a second supply roller 2. The core yarn filament A and the sheath yarn filament B sent out from the first supply roller and the second supply roller are introduced into the air injection nozzle 3, and the core yarn filament A is inserted between the rollers 1 and 4, and the sheath yarn filament B is is over-fed between the rollers 2 and 4, respectively, and is subjected to an entangling process through the air injection nozzle 3 to form a loop-shaped fluff. Next, the entangled core filament and sheath filament are overfed between rollers 4 and 5,
Alternatively, the material is subjected to relaxation or elongation heat treatment by a heater 6 while being under-fed, and its shape is heat-set, and then passed through a take-up roller 5 and wound up by a take-up roller 7.

In the interlacing process by the air injection nozzle 3, the injection processing feed rate of the core yarn filament A and the sheath yarn filament B is 0% or more, the feed rate of the core yarn filament A is +2% to +20%, and the feed rate of the sheath yarn filament B is set to 0% or more. The feed rate is preferably +10% to +40%, and more preferably, the feed rate difference between the core thread filament A and the sheath thread filament B is 10% to 25% in high tension, high speed rotation sewing. Good surface (excellent sewability).

If there is a large difference in the injection feed rate between the core yarn filament and the sheath yarn filament, a large amount of loop-like fuzz will occur, and the loop entanglement will not be completely fixed in the heat setting region described below. When this is sewn, the filament often comes loose in the needle part of the sewing machine, resulting in poor stitching and even thread breakage, making sewing difficult.

On the other hand, if the difference in injection feed rate between the core yarn and the sheath yarn is small, the pitch of the loop fluff will be coarse and the entanglement will be weak, which is not favorable for sewing.

As described above, the interlaced yarn of the air-injected core yarn filament A and sheath yarn filament B is sent to the heater 6.

The purpose of sending the injected intertwined yarn to the heater 6 for heat treatment is to increase the degree of fixation of the entanglement, reduce the hot water shrinkage rate, and increase the initial Young's modulus. The heat treatment temperature is 200℃ or higher, and 220℃ or higher to increase the degree of loop fixation.
230°C is preferred. The heat set feed rate between the roller 4 and the take-up roller 5 is +2 to -15%, preferably 0 to -10%. The type of heater 6 may be either a contact type or a non-contact type.

In the present invention, it is important that the hot water shrinkage rate of the filament used for the sheath yarn is 10% or more.

Utilizing this contraction force, the injected loop fluff is subjected to a relaxing heat treatment in a heat setting area to fix the loop.

The heat-set entangled yarn that has passed through the take-up roller 5 is wound up by a take-up roller 7.

Each of the above feed rates is calculated using the following formula.

Injection processing feed rate (%) Set feed rate (%) Roller decay 4 The sewing thread obtained by the above method of the present invention uses high-strength yarn as the core yarn component that maintains strength, and forms loop fuzz around it. By using high shrinkage thread for the sheath thread component,
The yarn does not have large loop-like fuzz and has few loop-like fuzz in the yarn length direction, and the length of the loop-like fuzz is 2.0 m.
The yarn has a total fuzz count of 300/M or more, a strength of 4.0 to 6.0 g/d, and an elongation of 15% to 3.
0%, and the spring water shrinkage rate is 2.0% or less, resulting in yarn with excellent thermal stability. Furthermore, the evaluations of the yarns described above and below were performed in accordance with the following.

Spring water shrinkage rate: According to JIS L1073-6.12 "Hot water shrinkage rate" measurement method.

Tensile strength and elongation: Based on JIS L1073-6.5 "Tensile strength and elongation" measurement method.

Fuzz length and number: Fuzz counting device (MODEL manufactured by Toshi)
DT-104) Depends on the measurement method.

Strength of entanglement: 0.5g using the device shown in Figure 2.
A load of /d was applied, and the sewing needle was repeatedly moved up and down for 10 seconds (50 times), and the strength of entanglement at that time was evaluated by a sensory test. The vertical movement speed of the needle at this time was 300 rpm. Soureisaku thread friction test:
The sample is fixed under load at intervals of 5 Qm with 120° angles as vertices. A metal edge is placed in the center and the number of thread breaks is measured when the thread is rubbed at 120 times/minute.

Strength retention rate after sewing: Remove the sewn thread from the fabric,
The tensile strength of the yarn is measured using Tensilon.

In the present invention, thermoplastic synthetic fiber filaments such as polyester can be used for both the core thread and the sheath thread. The filament A used for the core yarn has a single fiber denier of 3.0~
6. A polyester high-strength filament yarn having a strength of 5.0 to 9.0 g/d and a hot water shrinkage rate of 1.0 to 8.0% is preferred. The filament B used for the sheath yarn preferably has a single fiber denier of 0.5 to 4. Od, intensity is 3
．． A polyester filament yarn having a hot water shrinkage rate of 0 to (i, og/d, 10 to 60%) is used.

(Comparative Experimental Example) Next, a comparative experiment was conducted on the physical properties and sewability of the non-twisted sewing thread manufactured by the manufacturing method of the present invention and the twisted sewing thread manufactured by the known manufacturing method, and the results are shown in the table.

Sewing thread according to the present invention (sample number 1): As the filament constituting the core thread, polyester high strength filament thread 750d/192f (strength 8.
6g/d) as the filament constituting the sheath thread,
Polyester high shrinkage filament yarn 130d/48f (
The process of the present invention was carried out using the apparatus shown in FIG. 1 with a strength of 4.0 g/d and a spring water shrinkage rate of 45%. The processing conditions are processing speed Loom/min, core yarn filament injection overfeed rate of 5%, sheath yarn filament injection overfeed rate of 21% (the weight ratio of both used is core yarn 83.4%,
Sheath thread 16.6% air injection pressure cuff, 5kg/cn! ,
Elongation heat treatment underfeed rate 4%, heat setting temperature 230
Processing was carried out under conditions of ℃. The resulting yarn was dyed and coated with a silicone oil.

Comparison sample Nn2: 150d/48 for comparison with the sewing thread of the present invention
The polyester filament yarn f was used as the core yarn and the sheath yarn, and this was installed in the apparatus shown in FIG. 7, and the heat treatment by the heater 6 was omitted, and the other conditions were the same. Next, this yarn was given a number of first twists of 5430 T/M, and then three of the single yarns were pulled together and twisted together with a number of twists of Z350 T/M. Thereafter, the same staining conditions and the same oil agent as sample N11l were applied.

Comparison sample number 3: As comparison sample number 3, commercially available polyester spun sewing thread #8 is used as a synthetic sewing thread widely used in the industry.
was used.

Comparative sample number 4: Commercially available polyester filament sewing thread #8 was used as comparative sample number 4.

<Table 1> Thread breakage in the sewability test shown in Table 1 was evaluated using the maximum thread breakage tension when sewing 8 layers of T/C broadsheets with a lockstitch sewing machine rotation speed of 300 rpm.

■ The needle thread tension of the lockstitch sewing machine thread was 600 g, and the evaluation was based on the maximum thread breakage speed when sewing 8 layers of T/C broadcloth.

As is clear from the table above, the sewing thread of the present invention has higher thread abrasion strength and strength retention after sewing than conventional sewing threads, and is also effective in sewing dense thick fabrics such as 8 T/C broadcloths. It has excellent thread breakability and can withstand even severe sewing operations.

〔Effect of the invention〕

As detailed above, the sewing thread obtained by the method of the present invention has non-twisted loop-like fuzz by adjusting the feed rate of the filaments constituting the core yarn and the filaments constituting the sheath yarn in the bulk entangling treatment. Since sewing thread can be manufactured, it is possible to provide sewing thread with strong abrasion resistance and excellent heat resistance, which is suitable for high-speed, high-tension sewing, or thick fabric sewing.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of an example of an apparatus for manufacturing sewing thread of the present invention, and FIG. 2 is an illustration of an apparatus for testing the strength of intertwining of threads.

Claims (1)

[Claims] A method for producing a sewing thread in which a filament made of synthetic fiber constituting a core yarn and a filament made of synthetic fiber constituting a sheath yarn are simultaneously entangled and then heat set, the sheath yarn filament being set more than the core yarn filament. A method for manufacturing sewing thread, characterized by overfeeding.