JPS6081347A - Polyester sewing machine thread - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polynisder sewing thread using a novel bound spun thread that has excellent sewability and eliminates the problem of skipped stitches.

In recent years, polyester spun sewing thread has rapidly increased its market share due to its high strength, uniformity of brim quality, cost advantages, etc. However, compared to conventional cotton Katan thread, it has inferior sewability and has the drawback of frequently skipping stitches. However, there were many problems in terms of sewing efficiency and quality. As a result of in-depth research into the factors behind the frequent occurrence of stitch skipping in conventional polynisdelspun sewing threads, we found that stitch skipping is greatly influenced by the initial modulus of the sewing thread, and more specifically, the constituent fibers of the sewing thread. It was found that not only the modulus of the sewing thread but also the fiber axis orientation of the constituent fibers of the sewing thread have a large influence. In other words, conventional polyester spun sewing thread is made by piling together a plurality of single yarns that have been spun and twisted, and then twisting them so that the torque is applied in the opposite direction to the twisting of the single yarns. However, in the polyester spun sewing thread, the orientation of the constituent fibers in the yarn axis direction is extremely small.
The contribution of the constituent fiber modulus to the polynisdel spun sewing thread modulus is extremely small. Therefore, improving the yarn axis orientation of the constituent fibers leads to a greater contribution of the constituent fiber modulus to the polyester spun sewing thread modulus. For this purpose, it is effective to use bound spun yarn in which most of the constituent fibers are arranged parallel to the yarn axis direction. In view of this point, conventionally, two or more bundled spun yarns have a metric twist coefficient of 50 to 85 (converted to an index type of 1.65 to 2.81).
corresponds to ), and the surface of the sewing thread is coated with paraffin wax. However, in the bound spun yarn, the surface binding fibers that provide binding properties are wound at an angle almost perpendicular to the yarn axis direction so as to bundle the core fiber bundles oriented in the yarn axis direction. It has a major weakness in wear resistance because the surface binding fibers are easily cut due to wear in the axial direction. Therefore, although paraffin wax is attached to the sewing thread, it still has low abrasion resistance, making it unsuitable for severe sewing, especially when sewing thick fabrics at high speeds.

The present invention solves the drawbacks of conventional sewing threads using bound spun threads such as (2), and provides a new bound spun thread that has excellent sewability in severe sewing without the problem of skipped stitches. The purpose of the present invention is to provide a polyester sewing thread using polyester sewing thread.

To this end, the present invention has the following configuration. That is, the present invention has 1. A plurality of bundled spun yarns consisting mainly of polyester fibers of finite length and consisting of a substantially untwisted core fiber bundle and binding fibers wound around the core fiber bundle.The direction in which the binding fibers are wound is The yarn is twisted in opposite directions with a twist coefficient of 2.8 to 5.7 (inch system), and is characterized by having 1 to 10% by weight of a smoothing agent attached to the yarn. The present invention was developed by taking advantage of the structural characteristics of bound spun yarn and devising a constant coefficient.

The present invention will be explained in detail below. The bound spun yarn related to the polynisder sewing thread according to the present invention is mainly composed of polynisder fibers having a finite length. The polyester fiber referred to here is a polyester whose main constituent unit is an al-Trembrate unit, preferably a copolyester or homopolyester containing 80 mol% or more of ethylene terephthalate units, or a fiber-forming polyester consisting of a mixture thereof. refers to fibers obtained by In addition, finite length mainly refers to 100% stable fibers cut into unequal lengths or equal lengths, as well as continuous filament yarns such as continuous filament yarns or continuous multifilament yarns with the stable fibers as the main component. It refers to things that include. The fineness (denier) of the polyester fiber is preferably in the range of 0.2 to 3 deniers in consideration of the stiffness of the yarn. The bound spun yarn is mainly composed of finite length polyester fibers and has a traverse consisting of a substantially untwisted core m fiber bundle and bound fibers wound around the core fiber bundle. The binding fibers, which are part of the surface fibers, are wound around the core fiber bundle to impart cohesiveness to the binding spun yarn. Note that the bound spun yarn refers to a spun yarn produced by means such as a temporary nozzle having a swirling flow.

Next, a plurality of bundled spun yarns, preferably two or more, and more preferably two to six, are twisted together. This is to increase strength and wear resistance. Then, the twist coefficient (
inch system) is in the range of 2.9 to 5.7. This twist coefficient is particularly related to abrasion resistance, and is a factor that has a greater influence on the performance of sewing thread than in the case of conventional ring-spun yarn.If the twist coefficient (in inch system) is less than 2.9, severe sewing If it exceeds 5.7, the abrasion resistance will be insufficient, and if it exceeds 5.7, the modulus and strength of the sewing thread will decrease. Here, the twist coefficient (in inch system) is expressed by the following formula.

It's a hand. By the way, the binding spun yarn is given bundling properties by the binding fibers, but whether the wrapping direction of the binding fibers in this case is the same direction or the opposite direction to the twisting direction depends on the polyester sewing thread according to the present invention. This has a major impact on the quality of the product. Conventionally, a method of IJ twisting and twisting in the same direction to make sewing thread using bundled spun yarn has been proposed, but this method requires large yarn torque (due to large yarn torque, yarn strength, and yarn strength). modulus decreases
Therefore, in the present invention, as a result of elucidating the combination of a specific twist coefficient and the winding direction of the binding fibers during twisting, the winding direction of the binding fibers and the direction of combining and twisting are different, that is, opposite directions. That's what happened.

Furthermore, the reason why 1 to 10% by weight of a smoothing agent is attached to a plurality of bundled spun yarns is to increase smoothness and improve abrasion resistance. Compared to ring spun yarn, bound spun yarn lacks smoothness in morphology because the orientation of the bound fibers distributed on the surface is at a relatively large angle with respect to the yarn axis direction. 1-7 L The amount of smoothing agent applied to increase wear resistance.

is an important point. If it is less than 1% by weight, the abrasion resistance will not be sufficient, and if it exceeds 10% by weight, oil stains will easily occur, so the range of 1 to IO weight% is determined. The smoothing agent may include a smoothing agent containing polydimethylsiloxane as a main component, paraffin wax, etc., and the former is preferred. Further, the poly(methylsiloxane) is preferably a high viscosity polydimethylsiloxane whose aging at 25° C. is 1,000 centistoix or more, more preferably 3,000 centistoix or more. This is because if it is less than 1000 centistokes, the strength of the smooth film is low, and a large amount must be deposited, which tends to cause oil stains.

Next, a method for producing polyester sewing thread of the present invention will be explained. First, a stable fiber bundle of polyester fibers is drafted, and then a false-twist binding effect is applied using a false-twisting nozzle that generates a swirling flow to produce a bound spun yarn. A plurality of these bound spun yarns are combined and twisted in the opposite direction to the winding direction of the bundled fibers of the bound spun yarn with a twist coefficient of 2.9 to 5.7 (in inch system), and then ordinary polyester fibers are It is manufactured by dyeing according to the dyeing recipe and adding a smoothing agent of 1 to 10% by weight. Since the plied and twisted yarn has torque, it is preferable to heat set it, and in particular, in order to obtain a high modulus sewing thread, it is preferable to perform a stretching/relaxation heat treatment after plying and dyeing.

As described above, the polyester sewing thread of the present invention does not have the problem of skipped stitches (it has good sewability even during harsh sewing such as high-speed sewing, improves sewing efficiency, and has no troubles in the consumption process such as bunkering). High performance polyester sewing thread.

Example Polyester A fiber staple M fiber (1,2 denier
A sliver composed of 44 mm) is fed to a binding spinning machine, and a 150-fold draft is applied to turn the sliver in the Z direction to produce a bundled spun yarn of 60 count (English cotton count) using a false twist nozzle. did. Three of the bound spun 41i yarns were combined and twisted at a twist coefficient (inch system) of 4.37 in the direction (Z direction) opposite to the winding direction (S direction) of the bound fibers, and then twisted at 130° using a disperse dye. Stained with C x 40 minutes. After that, 25
The polyester sewing thread of the present invention was produced by adding 3% by weight (1 coat) of a smoothing agent mainly composed of polydimethylsiloxa having a viscosity of 3000 Cendestokes to the thread, and the sewing thread properties The sewing test results are shown in the table.

For comparison, the twisting direction and twisting coefficient (inch system) are shown below.
Sewing threads were manufactured in which 3% by weight of paraffin wax was attached to the threads, and the characteristics of the threads were also shown in the same table. Furthermore, sewing thread using polyester ring-spun thread (using a smoothing agent whose main component is polydimethylsiloxane) is also included in the same table for comparison. In the same table, tensile strength, cutting elongation,
The initial tensile resistance was determined by drawing a strength and elongation curve using a constant-speed extension type tensile test JA (Tensilon manufactured by Toyo Baldwin). Furthermore, skipped stitches and thread breakage in the sewing test were confirmed by sewing 5 layers of jersey 1 fabric (using Ii! thread 50/1'S) with a double chainstitch sewing machine (Union Special 5630ON).
Evaluation was made based on the number of times defects occurred when 0 pieces were sewn.

As is clear from the table, the IJ ester sewing thread according to the present invention exhibited excellent sewability with less skipped stitches and thread breakage than the sewing thread of the comparative example.

Also, even after ironing and washing, there was no occurrence of 'knob j'j', and the quality of the sewn product was extremely excellent.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] A plurality of bundled spun yarns mainly made of finite length polyester fibers, consisting of a substantially untwisted core fiber bundle #A and bundled fibers wound around the core fiber bundle are wound 11. Yarns that are twisted in the opposite direction with a linear coefficient of 2.8 to 5.7 (inch system), and a flat thread is attached to the yarn in an amount of 1 to 10%. A polyester sewing thread that is characterized by: