JPS6392743A - 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 [Field of Industrial Application] The present invention relates to a non-twisted sewing thread that has excellent abrasion resistance and heat resistance and is suitable for high-speed, high-tension top sewing or thick fabric sewing.

[Conventional technology]

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 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 along 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. =,xru.

On the other hand, in the case of spun sewing thread made of short synthetic fibers, it has the advantage of not being fused and cut due to low friction with the fabric, but has drawbacks such as uneven strength in the yarn length direction.

In order to compensate for the drawbacks of each of the three above, core spun yarns have been proposed in which a long fiber is used as the core yarn and short fibers are entwined around the core yarn. However, the strength has not improved enough to match the cost of the amplifier. In order to improve this, a conventional method for producing bulky intertwined yarns using jet flow has been proposed, for example, in Japanese Patent Application Laid-open No. 136947/1983. However, the sewing threads produced by these methods are made by subjecting multifilament threads made of synthetic fibers to bulky entangling treatment.
Next, the surface layer is raised by a rubbing method, and then twisted to obtain a sewing thread. The sewing thread obtained by this method has fluff around the twisted yarn with high binding properties that does not pull out, move, or increase, so it has higher strength than spun yarn or core spun yarn, and has no neps. The uniformity of the rows is good,
Even if it can be used for high-speed sewing, there remains a problem in that when sewing at high tension or sewing thick materials, cut threads are generated due to twisting and other causes, and the sewing performance is not sufficiently improved.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a heat-resistant non-twisted sewing thread with strong abrasion resistance and suitable for high-speed, high-tension sewing or thick fabric sewing.

[Means for solving problems]

The sewing thread according to the present invention to solve the above problem is a synthetic fiber multifilament sublime yarn consisting of a core thread and a sheath thread, in which the sheath thread is intertwined with the inner and outer layers of the core thread, and the outer periphery of the thread is It is characterized by forming loop-like fuzz on the surface.

The filaments constituting the core yarn are untwisted, but are preferably randomly intertwined.

The filaments constituting the sheath yarn are untwisted and have loop-like fuzz, and are interwoven with the core filaments by entering inside and outside the core filaments.

The length of the loop-like fluff of the sheath filament is approximately 2 ml.
Hereinafter, it is preferable that the number of loop-like fuzz is 300 fuzz/m or less.

〔Example〕

The invention will now be described in further detail with reference to the accompanying drawings, which illustrate embodiments of the invention.

In FIGS. 1 and 2, the filaments A constituting the core yarn converge in a substantially straight line while intertwining with each other at appropriate locations, while the filaments A constituting the sheath yarn having loop-like fluff B enters into the core yarn filament at various places, becomes entangled with it, and forms loop-like fuzz around the outer periphery of the core yarn.

The state of intertwining of the core filaments A and the strength of the intertwining are not particularly limited, and the core filaments A may be arranged in parallel in a straight line without being intertwined with each other. However, the strength of intertwining of the sheath filament B with the core filament A is evaluated by the sensory test described below, and is defined as one in which no filament dislocation occurs in the longitudinal direction of the yarn. It is preferable that the length of the loop-shaped fluff formed by the sheath filament is about 2 ml or less in total, and the total number of fluffs is 300 fuzz/m or more.

As the fiber material that can be used in the present invention, filaments in which both the core thread and the sheath thread are made of thermoplastic synthetic fibers such as polyester are suitable. As the filament A used for the core thread,
Single fiber denier is 3.0-6, Od, strength is 5.0
A polyester high strength filament yarn having 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.

Strength is 3.0-6.0g/d, hot water shrinkage rate is 10-60
% polyester filament yarn is used.

Next, one example of the method for manufacturing sewing thread according to the present invention will be explained.

FIG. 3 shows an example of an apparatus for carrying out the invention.

In the present invention, the intertwining of the core filament A and the sheath filament B is carried out by injecting an air jet stream through an air jet nozzle 3 used in the production of known loop intertwined yarns. Then, the air pressure, feed rate, heat cut, nozzle shape, etc. are adjusted to the processing conditions such that loop entanglement is strong and hot water shrinkage rate is low. In FIG. 3, the core yarn filament A is introduced into the first supply roller 1, and the sheath yarn filament B is introduced into the second supply roller 2.

The core yarn filament A and the sheath yarn filament B sent out from the first supply roller 1 and the second supply are introduced into the air injection nozzle 3. When introducing into the injection nozzle 3,
The core filament A and the sheath filament B are interlaced between rollers 1 and 4, while the sheath filaments are overfed between the rollers 2 and 4, and the sheath filaments are intertwined. A looped fuzz of filaments is formed. The yarn thus entangled is over-fed or under-fed between the rollers 4 and 5, while being relaxed or elongated by the heater 6, and its shape is fixed by heat, and passed through the take-up roller 5. It is wound up by a winding roller 7.

The injection feed rate of core yarn filament A and sheath yarn filament B should be 0% or more, the injection feed rate of core yarn filament A should be +2% to +20%, and the injection feed rate of sheath yarn filament B should be +10% to +40%. Preferably, and most preferably, one in which the feed difference between the core filament A and the sheath filament B is 10% to 25% provides a good seam surface and excellent sewability under high tension and high speed rotation. becomes.

If there is a large difference in the injection feed rate between the core yarn and the sheath yarn, a large amount of loop-like fuzz will occur, making it impossible to completely fix the loop entanglement in the heat setting region described below. When this is sewn, the filament often comes loose at the sewing machine needle hole, causing poor stitching and even thread breakage, making it impossible to sew. 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, resulting in unsatisfactory sewability.

The heat treatment temperature is 200°C or higher, preferably 220-230°C.
℃ has the best degree of loop fixation. Further, the heat set feed rate is +2 to -15%, preferably 0 to -10%.

Further, 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 filaments constituting the sheath yarn is 10% or more, and by utilizing this shrinkage force, the injected loop-shaped fluff is relaxed and heat-treated in the heat setting area to fix the loop. We aim to

Alternatively, large loop-shaped fuzz larger than approximately 2 mm is removed and completely fixed without elongation heat treatment in a heat setting area. If the hot water shrinkage rate of the sheath thread is less than 10%, the entanglement will be weakly fixed no matter how much elongation heat treatment is performed in the heat center area, and when an impact force is applied due to friction in the sewing machine needle hole, filament break-up will occur, making it impossible to sew. Sexually undesirable.

The sewing thread of the present invention formed by the above method has a strength of 4.0 to 6.0 g/d and an elongation of 15 to 30.
%, and the hot water shrinkage rate was 2.0% or less.

In the above embodiment, each feed rate is calculated as follows.

Injection processing feed rate (%) Heat set feed rate (%) (Comparative experiment example) Next, a comparative experiment was conducted on the physical properties and sewability of the untwisted sewing thread according to the present invention and the known twisted sewing thread, and the The results are shown in the table.

Sewing thread according to the present invention (sample 1): Polyester high strength filament thread 750d/192f (strength 8,
Polyester high shrinkage filament yarn 130d/d was used as the filament constituting the sheath yarn.
48f (strength: 4.0 g/d, fresh water shrinkage rate: 45%) was installed in the apparatus shown in FIG. 3 to carry out the processing of the present invention. The processing conditions were a processing speed of 100 m/min, a jetting overfeed rate of 5% for the core yarn filament, and a jetting overfeed rate of 21% for the sheath yarn filament (the weight ratio of both used was 83% for the core yarn).
．． 4%, sheath thread 16.6% air injection pressure cuff, 5kg/cd
The processing was carried out under the conditions of an elongation heat treatment underfeed rate of 4% and a heat setting temperature of 230°C. The resulting yarn was dyed and coated with a silicone oil.

Comparison sample number 2: 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. 3, and the heat treatment by the heater 6 was omitted, and the other conditions were the same. Next, this yarn was given a first twist of S430T/M, and then three of the single yarns were pulled together and twisted together with a twist of Z350T/M. Thereafter, the same staining conditions and the same oil agent as Sample 11hl were applied.

Comparative sample 3: As comparative sample 11h3, commercially available polyester spun sewing thread #8 was used as a synthetic sewing thread that is widely used in the industry.

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

Table 1 is shown in the margin below. Thread breakage in the sewability test in Table 1 is evaluated using the maximum thread breakage tension when sewing 8 layers of T/C rope on a lockstitch sewing machine at a rotation speed of 300 rpm. did.

■ 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 had excellent thread breakability and was able to withstand harsh LII manufacturing.

In addition, in this specification, the evaluation of yarn was performed in accordance with the following.

Hot water shrinkage rate: According to JIS L1073-6/12F 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 (east side frontage EL)
DT-104) According to the measurement method.

Strength of entanglement: 0.5g using the device shown in Figure 4.
The sewing machine needle was repeatedly moved up and down for 10 seconds (50 times) under a load of /d, 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+. In evaluating the strength of entanglement, ◎ indicates that no filament scattering occurs in the longitudinal direction of the yarn according to a sensory test.

Thread friction test: The sample is fixed under load at 6011 intervals with the 120° angle as the vertex. 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.

! 1 IIWA cutting tensile knife [Effect of the invention] The sewing thread according to the present invention configured as described above has a structure in which the filaments constituting the sheath thread having loop-like fluff are intertwined between the filaments constituting the core thread and around the core thread. Since there is no twisting, it has excellent wear resistance and/or heat resistance, and can be used at high speeds.
Suitable for high-tension sewing or thick fabric sewing, and does not cause thread breakage.

[Brief explanation of the drawing]

FIG. 1 is a side view of the sewing thread according to the present invention, FIG. 2 is a sectional view of the sewing thread according to the present invention, FIG. The figure is an explanatory diagram of a device for testing the strength of yarn entanglement. Figure 2

Claims (1)

[Claims] A synthetic fiber multifilament sublime yarn consisting of a core yarn and a sheath yarn, characterized in that the sheath yarn is intertwined with the inner and outer layers of the core yarn, and a loop-shaped fluff is formed around the outer periphery of the yarn. sewing thread.