JPS6175835A - Polyamide filament yarn - 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 (Field of Industrial Application) The present invention relates to a polyamide filament sewing thread having excellent sewing properties at high speeds.

(Conventional Technique #i) Filament sewing threads such as polyethylene terephthalate and nylon 6 have various properties such as high strength, high modulus, excellent dimensional stability, and little change in physical properties over time. Also, because it is inexpensive, it is widely used for clothing and industrial purposes.

However, when conventional filament sewing thread is sewn under harsh conditions, such as when sewing at high speed or when sewing thick fabrics, there are problems such as melting and cutting due to the high temperature of the needle, and an extreme decrease in strength during sewing. Improvements were requested. For example, methods for improving the sewability of conventional polyester filament sewing thread include reducing the friction by reducing the twist angle between the polyester filament sewing thread and the constituent filaments, and using high viscosity silicone oil. There are also known methods for improving the high-temperature dynamic friction characteristics by using such methods, but these known methods do not significantly improve the neck point of sewability.

(Problem to be solved by the invention) Conventional sewing thread made of polyamide fiber has excellent strength and robustness, so it is necessary to satisfy the wash and wear characteristics associated with the combination of fabrics to be sewn. In recent years, it has become widely used as an alternative to cotton sewing thread, but compared to cotton sewing thread, it has poor high-speed lockstitching properties, has many skipped stitches, and has sewing problems.

The main reason for poor high-speed sewing performance of polyamide sewing thread is, for example, when using nylon 6 or nylon 66.
Heat resistance is at most 230'0 or 260℃, respectively.
Because of this, during high-speed sewing, the RJ of the sewing machine thread becomes extremely low due to the high temperature of the sewing machine needle, and the sewability of the sewing machine thread is significantly reduced.Additionally, the dimensional stability is not good and puckering occurs as the sewing machine cools down. It had been.

(Means for solving problems) The above problems are solved as follows.

That is, the present invention is a polyamide filament sewing thread made of nylon 46 fibers having a relative viscosity of 2.4 or more, and characterized in that the sewing thread has a dry heat shrinkage rate of 3% or less at 160''G.

Nylon 46, which is the raw material for the fiber produced in the present invention, has a molecular chain with a repeating unit of 90% or more E-NH-((H2)
A polyamide consisting essentially of poly(tetramethylene adipamide) composed of 4-NHco-(OH2)4-co9, comprising an ε-capramide component, a hexamethylene adipamide component, and a hexamethylene terephthalamide component. , copolymerized with 10% or less of a third component such as undecamethylene terephthalamide component, or polymers consisting of these, such as poly(ε-capramide), poly(hexamethylene adipamide), poly(hexamethylene adipamide), etc. It may also contain a blend of 10% or less of poly(undecamethylene terephthalamide), poly(undecamethylene terephthalamide), etc.

In addition, if necessary, it is possible to add a retardant, a pigment, a light stabilizer, a heat stabilizer, an antioxidant, an antistatic agent, a dyeability improver, an adhesion improver, etc., depending on the combination. All can be used, except those that have a significant adverse effect on the characteristics of the invention.

The fibers constituting the sewing thread of the present invention are dissolved in a 96.3% concentrated sulfuric acid solution to a polymer concentration of 10rn9/fnl, and the relative viscosity of the dissolved solution measured at 20°0 is 2. , 4 or more, and furthermore, in order to obtain a stronger sewing thread, the relative viscosity is preferably 3.0 or more.

The melting point of the nylon 46 fiber in the present invention is 275°C or higher, and the melting point of nylon 6 or nylon 66 is about 23°C.
One of its characteristics is that it is extremely high compared to 0 to 260°C, and when used as a filament sewing thread, it contributes to improved heat resistance against frictional heat.

The dry heat shrinkage rate of the sewing thread of the present invention at 160°C is 3%.
Below, the dry heat shrinkage rate is preferably 2.5% or less, and if the dry heat shrinkage rate exceeds 3%, the dimensional stability against heat or washing will be poor, and puckering will occur during the consumption process of the sewn product. I don't like this because it causes problems.

In the present invention, the dry combustion shrinkage rate at 160°C is the length when an initial load of 1/3 og/d is applied! After leaving the sample in air at 160°C for 30 minutes without tension,
From sample length 11 when applying a load of 309/d ((A
'. -4)/1o)x100.

Next, a method for manufacturing the polyamide filament sewing thread of the present invention will be described, but the present invention is not limited to the following method.

The process is important in producing the polyamide filament sewing thread of the present invention. First, a nylon 46 polymer having a relative viscosity of 2.4 or more is melt-spun. In the melt-spinning process, the molten polymer is discharged at a spinning humidity of 300 to 320°C, and then a nylon 46 polymer having a relative viscosity of 2.4 or more is discharged at a spinning humidity of 300 to 320°C.
After passing through a heating range of 200 to 400 mm maintained in an atmosphere of 28Q°C, it is cooled and solidified, and then rolled up.

The undrawn yarn obtained in this way is continuously spun or after being wound up once, and when it is stretched, it is brought into contact with a plate heater at 200 to 240°C between the first drawing roller and the second drawing roller. The nylon 46 drawn yarn is obtained by drawing the yarn by ~4.5 times. As mentioned above, nylon 46 polymer has a high melting point, so the spinning temperature and drawing temperature are higher than conventional ones, and high drawing temperatures are also required to keep the shrinkage rate of the final sewing thread at 160°C dry heat to 3% or less. It is.

In this way, the N nylon 46 filament thread is heated and dyed according to a conventional method to become a sewing thread.

The stiffness of the nylon 46 filament constituting the sewing thread of the present invention is preferably in the range of 1 to 7 deniers. If the fineness of the nylon 46 filament is less than 1 denier, when it is sewn as a sewing thread, the single fibers will easily break due to friction with the guide or frictional resistance when penetrating the fabric, and thread breakage will occur easily. Since the sewing thread becomes hard and difficult to bend, making it impossible to form clean stitches, a range of 1 denier or more and 7 denier or less is preferable.

Furthermore, filament yarns include multifilament yarns and monofilament yarns, and multifilament yarns are preferred. This is because clean seams are formed. The number of twisted filament yarns is preferably 2 to 6. This is for sewability.

(Examples) Hereinafter, the configuration and effects of the present invention will be explained using examples, but the present invention is not limited by the following examples.

The methods for measuring the main parameters used to measure the physical properties of the fibers constituting the present invention, and the evaluation methods for fusing temperature, number of rims, skipping, and puckering used in the evaluation of the present invention are shown below.

<Measurement method of relative viscosity> 96.3 ± 0.1 wt% Reagent Prepare a sample solution by dissolving the sample in special grade autosulfuric acid so that the polymer concentration becomes 1 off + 97, 20'O ± 0.05 The relative viscosity of the solution is measured using an Ostwald viscometer with a water fall time Wi of 6 to 7 seconds at a humidity of 'a. When measuring, use the same viscometer.1. The relative viscosity RV is calculated using the following formula from the ratio of the falling time T0 (seconds) of 20 td of sulfuric acid, which is the same as when preparing the sample solution, and the falling time T0 (seconds) of the sample solution 20-.

RV Tomi T□/T.

Fusing temperature> Sewing thread is passed through a cylindrical heater with an inner diameter of 8 mm and a length of 150 mm, a weight of 0.1 mm/d is suspended from one end, and a stress detector is connected to the other end. And the temperature inside the cylindrical heater is 2
The temperature was raised at a rate of 4° C./min, and the temperature at which the sewing thread was cut and the stress detector showed 0 was defined as the fusing temperature.

Number of hems> Using a lockstitch sewing machine (Singer 770Dl model), polyester/cotton blend work clothes fabric (basis weight 27097 m) was made using a sewing machine needle DB 14, machine rotation speed 4000 rpm, number of N stitches 15 stitches/3 c+++. The sewing length zm+ when sewing is shown as the maximum number of layers that can be sewn.

<Eye Jump> Using a 2IAA sewing machine (Union Special 5630ON), 5 and 2 pieces of cotton jersey knitted fabric (using 50″I/1 cotton thread)
Sewing machine rotation speed 400 Orpm for fabrics with stacked layers
The quality of the occurrence of skipped stitches when sewing was indicated by ○×.

Puckering> Sewn products were observed after normal iron pressing and washing, and puckering was indicated by ○×.

seam appearance The seams give a sensual look.

Example L Nylon 46 chips with relative viscosity 2.5 are used as raw material and pore size is 0.
．． It was melted and discharged at 310°C using a 35mm spinneret with 24 holes, passed through the heating zone of 3QQ IIIJ kept at 240°C, cooled and assimilated, then wound up, and then passed through a hot plate kept at 2LO°C. The film was drawn at the draw ratio shown in Table 1 to obtain a drawn filament of 70 denier 24 filaments. Next, the obtained filament yarns were first twisted to S 880 T/+m, and three yarns were combined to form Z5
After applying a 60T/z ply twist, total dyeing was carried out at 100°C for 60 minutes, and 3% silicone oil was applied to make a 50% nylon 46 filament sewing thread, and the sewing thread was tested for sewability. Ta.

Table 1 shows the results of the evaluation of the physical properties and sewability of the sewing thread.

Comparative Example L Using nylon 6 chips with a relative viscosity of 2.5 as a raw material, filament sewing thread was prepared under the same spinning conditions as in the actual example except for the spinning conditions shown in Table 1, and the sewing ability of the sewing thread was A sex test was conducted.

Table 1 shows the results of the evaluation of the physical properties and malletability of the sewing thread.

Table 1 (Effects of the Invention) The polyamide filament sewing thread of the present QJ 1llJ does not easily melt even under high-speed planting conditions, where conventional polyamide sewing thread would easily melt, and has a high fusing temperature. It has great heat resistance, and has excellent sewability with many pongee sheets and no skipped stitches.M
ar: The condition of the upper is very good, the marks are clean, there is no puckering, and the quality of the sewn product using the polyamide filament sewing thread of the present invention is excellent.

Claims (1)

[Claims] Made of nylon 46 fibers having a relative viscosity of 1.2.4 or more, the dry heat shrinkage rate of the sewing thread at 160°C is 3%.
A polyamide filament sewing thread characterized by: 2. The polyamide filament sewing thread according to claim 1, wherein the filament has a fineness of 1 to 7 deniers. 3. The polyamide filament sewing thread according to claim 1 or 2, wherein the sewing thread is formed by twisting and twisting multifilaments.