JPS63211333A - Production of nylon 6 sewing machine 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 (Industrial Application Field) The present invention relates to a method for producing sewing thread made of nylon 6 false-twisted thread.

(Prior art) Conventionally, melt-spun nylon 6 filament yarn was
%, the drawn yarn is cold-stretched 3 to 4 times to have a residual elongation of 38 to 42%, and then the drawn yarn is subjected to false twisting, and this yarn is passed through a sewing machine. It is known to be used as thread.

A yarn obtained by false twisting nylon 6 drawn yarn by this spinning-drawing method has an elongation of 30% or less and excellent crimp fastness, and is suitable as a sewing thread.

However, the sewing thread described above was expensive and did not have sufficient crimpability.

In recent years, a method of false twisting highly oriented undrawn yarn spun at a spinning speed of 3500 w/min or higher has been adopted. When the highly oriented undrawn yarn obtained by this high-speed spinning is false-twisted, it has more uniform dyeing and improved crimpability compared to when the drawn yarn is false-twisted by the spinning-drawing method. It has the characteristics of good processing stability during false twisting and cost reduction. As a method for false twisting nylon 6 highly oriented undrawn yarn, for example, 1
18456, the twisting angle is 426-45° and the heater temperature is 160-185°C.

A method is disclosed in which the stretching ratio is set to 1.06 to 1.33 times. However, the false twisted yarn produced by this method has a somewhat satisfactory crimpability.

When false-twisting is performed under the above conditions, the residual elongation of the resulting false-twisted yarn exceeds 30%.

The S-twist and Z-twist single yarns of this false twisted yarn were combined and twisted.

If you dye the yarn after finishing the whole process to make yarn-dyed sewing thread,
There is a problem in that skipped stitches occur during sewing, leading to poor sewing.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems, and its purpose is to have low elongation and good high crimp fastness,
Moreover, the present invention provides a method for manufacturing nylon 6 sewing thread having high crimpability at a low cost.

(Means for Solving the Problems) That is, in the present invention, the birefringence is 36×10−3 to 42×
The number of false twists T (t
/m) to 31800/ f t ≦ T ≦ 35800/ f
Stone (however.

D is the denier of undrawn yarn), the twisting tension is 0.11 to 0.14 g/d, and the heater temperature is 1135 g/d.
False-twisted yarns with the S-twist and Z-twist in the false-twisting heating direction are produced by maintaining the temperature at ~193°C and twisting the resulting false-twisted yarns with the S-twist and Z-twist. The gist of the present invention is a method for manufacturing nylon 6 sewing thread, which is characterized in that it is made into thread.

Two aspects of the present invention will be described in detail below.

First, in the present invention, the birefringence is 36X10-3~4
It is necessary to use 2X10-' nylon 6 highly oriented undrawn yarn. When the birefringence is less than 36 x 10-', the yarn lacks stability over time, making it impossible to obtain a stable false twisted yarn, while on the other hand, when the birefringence exceeds 42 x 10-3.

This is not preferable because the crimpability of the resulting false twisted yarn is reduced.

The above-mentioned highly oriented nylon 6 undrawn yarn with a birefringence of 36X10-3 to 42X10-'' was spun at a spinning speed of 4000 m/min.
Obtained by the above high speed spinning. Spinning speed is 4000
If it is less than m/min, the obtained highly oriented nylon 6 undrawn yarn will swell and the winding appearance of the winding package will tend to be poor.
During false-twisting, the unwinding tension fluctuates, which tends to cause yarn breakage, and in order to ensure stable processing operability, clusters may occur in the false-twisted yarn. Therefore, in order to obtain the above-mentioned highly oriented nylon undrawn yarn, 4000
m/min or more preferably 4100 to 5000 m/m
in is adopted.

Next, the number of false twists T (t/m) is 31800 /V'U≦
It is necessary to adopt the range T≦35800/¥U. Here, D is the denier of the highly oriented nylon 6 undrawn yarn. When the number of false twists exceeds 35,800/Xn5.

The strength of the resulting false-twisted yarn decreases, and the strength after making it into yarn-dyed yarn cannot meet the strength required for sewing thread, and fuzz and yarn breakage occur during the false-twisting process. Stable operability cannot be ensured. On the other hand, 31800
If the number of false twists is less than /√D, the residual elongation of the false twisted yarn will be high, and when used as a sewing thread for sewing, skipped stitches will occur, leading to poor sewing.

Next, the twisting tension during false twisting is 0.11 to 0.14.
g/d, and by adopting a twisting tension within this range, a false twisted yarn that maintains high strength can be obtained. When the twisting tension exceeds 0.14 g/d, the strength of the resulting false twisted yarn decreases.

On the other hand, when it is less than 0.11 g/d, the heating balloon becomes large, and the strength and elongation of the processed yarn in the longitudinal direction vary widely, and yarn breakage is likely to occur, resulting in poor production efficiency.

Furthermore, in the present invention, the heater temperature during false twisting is set to 185%.
The temperature is set at ~193°C to sufficiently heat-set the twist imparted in the false-twisting heating range and to reduce the residual elongation of the false-twisted yarn. This heater temperature is preferably 188°C or higher. When the heater temperature is lower than 185°C, the residual elongation of the false twisted yarn becomes high.

Crinkability decreases. On the other hand, if the temperature exceeds 193°C, the strength of the false twisted yarn decreases, and the strength required for sewing thread cannot be obtained.

The highly oriented undrawn nylon 6 yarn is false-twisted as described above to produce a false-twisted yarn with an S-twist and a Z-twist in the false-twist heating direction, and the S-twisted false-twisted yarn is A sewing thread is formed by combining and twisting the Z-twisted false twisted yarn to make a double yarn. The twist direction during this combined twist is S.

Any Z direction may be used, and the number of twists is 80 to 200 t.
/m is preferred. The sewing thread according to the invention thus produced has a low residual elongation of less than 30%, good high crimp fastness and high crimpability.

(Function) When sewing stretchable fabric, the sewing thread used as the sewing thread is stretched and sewn, and when the fabric returns to its original position after sewing, the sewing thread also returns to its original position. It becomes necessary. During this sewing process, a large amount of tension is applied at the moment the seam is formed.

If crimpability, that is, stretchability is low, skipped stitches will occur.

In addition, if the crimp fastness is low, the crimp of the yarn will decrease.

The above-mentioned return after sewing is reduced, and the fabric becomes sagging.

According to the method of the present invention, sewing thread that meets the above requirements can be easily obtained. In other words, in the method of the present invention, a highly oriented undrawn nylon 6 yarn having a specific birefringence is false-twisted at a specific number of false twists, a twisting tension, and a heater temperature to produce a false-twisted yarn with S2 and Z twists. Since these are twisted and twisted, a sewing thread having a low residual elongation of 30% or less, high crimpability, and good crimp fastness can be obtained at a low cost.

Since the sewing thread produced by the method of the present invention has low residual elongation, there are no problems such as skipped stitches or thread breakage during sewing. Furthermore, since the sewing thread produced by the method of the present invention has high crimpability and good crimp fastness, it can be used even when sewing highly elastic woven or knitted fabrics.

The stitches after sewing do not sag or sag, and the stretchability of the woven or knitted material is sufficiently maintained, allowing it to stretch and contract in accordance with the stretching behavior of the woven or knitted material.

(Example) Next, the two methods of the present invention will be specifically explained using examples.

In the examples, crimp fastness is measured by the following method.

Using a constant speed extension type tensile tester equipped with a self-recording device,
Apply an initial load of 0.1 g/d to the yarn, set the distance between the grips to 20CI11, and pull the yarn at a load of 3.0 g/d at a tension rate of 100% of the grip interval per minute. Unload at the same speed as above.

The residual elongation is determined from the recorded load-elongation curve, and this value is defined as the crimp fastness. here.

A crimp fastness of less than 8% is considered to be good crimp fastness.

In addition, other physical properties are measured in accordance with JIS.

Example 1. Comparative Examples 1 to 4 Nylon 6 highly oriented undrawn yarn 130d/24f was false twisted into S twist and Z twist using Mitsubishi Heavy Industries (barrel false twisting 1Ls-6 type) under the conditions shown in Table 1. Twisting and ZI′
! ! A false twisted yarn of i was obtained. During the false twisting process, the number of windings on the spinner is 2 in all cases.

The feed rate during winding was +4.0%. Above S twist and Z
The false twisted processed yarn was twisted together in the Z direction at a twist rate of 120 t/m to form a double yarn. Next, this twin yarn was made into a general shape and subjected to certification dyeing using an Obermeyer dyeing machine to obtain a sewing thread.

As is clear from the results shown in Table 1, the sewing thread obtained by the method of the present invention has a low residual elongation equivalent to that of the sewing thread obtained by false twisting the drawn thread by the spinning-drawing method. Ta. In addition, the crimp fastness is 6.5%, which is equivalent to the sewing thread obtained by false twisting the drawn yarn by the spinning-drawing method, and the stretch elongation rate is 223%.
% and had high crimpability.

On the other hand, the number of false twists is 31800 / surface = 278
Comparative example 1. lower than 9 (t/m). Heater temperature is 185℃
Comparative example 2. Both Example 3 with a birefringence of 35×10-' and Comparative Example 4 with an untwisting tension of less than 0.1 g/d had a residual elongation of 30% or more and were unsuitable as sewing threads. Ta.

(Effects of the Invention) According to the method of the present invention, a nylon 6 sewing thread having low elongation, good crimp fastness, and high crimpability can be provided at a low cost.

Claims (1)

[Claims] (1) Birefringence is 36×10^-^3 to 42×10^-^
The number of false twists T (t/m) of highly oriented nylon 6 undrawn yarn of 3
31800/√D≦T≦35800/√D (however, D
is the denier of undrawn yarn), and the twisting tension is set to 0.
．． 11~0.14g/d, heater temperature 185~193
False-twisted yarns with S twist and Z twist in the false twist heating direction are produced by keeping at ℃ and false-twisting, and the resulting S-twist and Z-twist false-twisted yarns are combined and twisted to form twin yarns. A method for producing nylon 6 sewing thread.