JPS5843484B2 - Fiber for nylon 6 false twisted yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nylon 6 false-twisted yarn fiber that has excellent level dyeing properties and improved crimp properties.

Conventionally, in order to false-twist nylon 6 fibers, the undrawn nylon 6 yarn that has been spun is generally wound up while being subjected to appropriate heating treatment, and then it is rolled up to have an elongation of 30 to 40% in the drawing process. In this method, a pirn that has been stretched approximately 3 to 4 times is used as a raw yarn.

However, such conventional drawn yarn is easily affected by moisture, so there is a large difference in yarn quality between the inner, middle, and outer layers of the pirn, and between the end face and the center. It has the disadvantage that it causes fluctuations and that only processed yarns with poor level dyeing and crimp properties can be obtained.

The object of the present invention is to eliminate the various drawbacks of the prior art, and to obtain a high-quality false-twisted yarn with no fluctuation in the number of false twists and excellent in level dyeing and crimp characteristics. The aim is to provide fiber.

Therefore, the object of the present invention is to achieve dry heat shrinkage stress 5 (60°C), 5
(100°C) and 5 (160°C) below 1).
A fiber for nylon 6 false-twisted yarn that satisfies formula (2) at the same time.

This can be achieved by

In the present invention, dry heat shrinkage stress refers to the stress measured by the following method.

24 nylon 6 fibers were placed in a test chamber at 20°C and 65% RH.
After standing for a period of time, a 20 cIrL length sample was taken, both ends of which were gripped by stress detectors installed in the heater, and the sample and its surroundings were heated at a heating rate of 2.5°C/mix. The shrinkage stress generated in the sample is detected, and this is charted with temperature on the horizontal axis and stress on the vertical axis, and the noise portion is smoothed out to obtain a graph as shown in FIG.

From the obtained graph, 60℃, 100℃ and 160℃
The shrinkage stress in each sample was read, and P/d, which was obtained by dividing each shrinkage stress by the fineness of the sample before heating up, was recalculated as a unit of stress.

The present invention provides a ratio of dry heat shrinkage stress 5 (100°C) at 100°C to dry heat shrinkage stress 5 (60°C) at 60°C measured by such a method: 5(100°c)/S(6
<)0c) must satisfy the condition of 0.8 or more and 1.2 or less.

The reason for this is that in the false twisting process of nylon 6 fibers,
By running the yarn on a hot plate, the temperature is raised from room temperature to the set temperature on the hot plate. In this case, the number of twists and yarn diameter vary depending on the processing speed, number of filaments, denier, etc. Although it is different, approximately 10 CrrL from the hot plate inlet
It becomes constant at the position that has been traveled for some time.

The yarn temperature at this position is in the range of 60 to 100°C, and it is believed that amorphous segment motion occurs most frequently in this temperature range.

However, since the dyeability depends on the degree of orientation of amorphous chains and the volume of voids, in this temperature range where rearrangement of amorphous chains is most likely to occur, the shrinkage stress ratio of 5 (100°C)/
5 (60°C) within a limited range, processing tension unevenness during false twisting and orientation unevenness in the length direction of the false-twisted yarn will be reduced, resulting in no change in the number of false twists and dyeing. It is considered that processed yarn without unevenness can be obtained.

When 5(100℃)/5(60℃) is less than 0.8, moisture absorption unevenness is large and difference between weights is likely to occur, and when it exceeds 1 or 2, processing tension unevenness occurs during false twisting. This is undesirable because it tends to become a dog and causes staining spots.

Further, the nylon 6 fiber according to the present invention has a ratio of heat shrinkage stress 5 (160°C) at 160°C to dry heat shrinkage stress 5 (100°C) at 100°C 5 (160°C)/S
(100°C) must be 1.5 or less.

The reason for this is that in the temperature range from 100°C to around the hot plate temperature, the phenomenon of partial melting and recrystallization of crystal parts occurs, and in this region the family length of the crystal is large.
It is thought that those with a large structural change have excellent crimp characteristics.

In this sense, in the present invention, 5(160°C)/5(100°C)
It is important that C) be 1.5 or less, preferably 1.0 or less.

When 5(160°C)/5(100°C) exceeds 1.5, the crimp characteristics deteriorate and it is impossible to obtain a good textured yarn.

The nylon 6 fiber according to the present invention is, for example, nylon 6
The chips are melted, spun from a spinneret, cooled and solidified, and the resulting undrawn yarn is continuously processed from 1.1 to 1.1 without winding it up.
It can be obtained by cold stretching at a low magnification of about 5 times, and winding it up without heat treatment after cooling and solidifying.In this case, the birefringence before stretching is 18 x 10'' to 40 x 10-
It should be around 3.

Figure 1 illustrates the dry heat shrinkage stress curves of various nylon 6 fibers. Curve A is a normal nylon 6 undrawn yarn (
230D-24F), curve B shows an example of nylon 6 fiber (80D-24F) according to the present invention, and curve C shows an example of normal drawn yarn (70D-24F).

Since the fiber of the present invention is constructed as described above, when it is used as yarn to be fed to the false twisting process,
It is possible to obtain a high-quality nylon 6 false-twisted yarn with no fluctuation in the number of false twists and excellent level dyeing properties and crimp characteristics.

In the following examples, level dyeing means that each false-twisted sample is sequentially made into a tubular knitted fabric, and this is
Black WANo, 2% owf1 A relative evaluation of the dyed with ammonium sulfate 8% owf at 60℃ in the same bath.Those with no dyeing spots at all are divided into ◎, and the remaining three are divided into ○ and △.
・The level dyeing properties were ranked as poor in the order of ×.

In addition, the crimp stiffness is defined as the S and Z false-twisted yarns are pulled together, stretched out under a load of 0.1/d, and then stretched under a tension of 21119/d. A hot water treatment is performed at 60°C for 5 minutes, then the temperature is raised to 98°C for 10 minutes, and a hot water treatment is performed at 98°C for 30 minutes.

After air-drying this, read the length No. after 2 minutes under a load of 0, i/d in water at 20℃, immediately change the load to 21n9/d, and read the length (11) after 2 minutes. Read and calculate using the following formula.

Example Nylon 6 chips having a relative viscosity ηr of 2.5 are melted at 260° C., spun through a spinneret having a diameter of 0.3 mm, cooled and solidified, and then continuously cold-stretched and wound up.

At this time, by changing the take-up speed of the spun yarn, the birefringence before drawing was set to the value shown in Table 1, and a fiber was obtained that simultaneously satisfied the drawing conditions.
and 6.

In addition, by changing the spinning and drawing conditions, fibers that did not satisfy the present invention were obtained, and these were used as samples/I61, 2, 3,
7, 8 and 9.

Sample /i61 was an undrawn yarn wound at 800 m/min without drawing, and the dry heat shrinkage stress curve showed the pattern shown in FIG. 1A.

Samples /162 and /I63 are fibers that are wound at high speed without drawing, so-called high-speed* real yarn spinning (A2 is 40
00 m/min, /16.3 is 4500 m/min), and the dry heat shrinkage stress curve showed the pattern shown in FIG. 1E.

Sample/16.7 is an undrawn yarn that has been wound once at a spinning speed of 800 rn/min.
For sample /i6.8, the undrawn yarn was similarly wound at a spinning speed of 800 m for 7 minutes, and was drawn at a drawing ratio of 3.
．． 5 times, hot-stretched at a hot plate temperature of 150°C and a stretching speed of 600 m/min, and their dry heat shrinkage stress curves are as follows:
The pattern shown in Figure C is shown.

In addition, sample flat 9 is a fiber produced by the so-called direct spinning/drawing method, in which undrawn yarn is drawn 2.5 times at room temperature at 3500 m/min, then heat-set at 160°C and continuously wound.
The dry heat shrinkage stress curve showed the pattern shown in the first diagram.

Each of these fibers is false-twisted under false-twisting conditions that provide the highest degree of crimp firmness.

Table 1 shows the curling firmness and level dyeing properties of the obtained processed yarn.

The common false twisting processing conditions are: hot plate temperature 180°C, spindle rotation speed 34.0000 rpm, yarn speed 100 m/,
m, and the finished processed yarn high deviation is also 70D-24F.

[Brief explanation of the drawing]

FIG. 1 illustrates dry heat shrinkage stress curves of various nylon 6 fibers.

Claims (1)

[Claims] Dry heat shrinkage stress at 160°C, 100°C and 160°C 5 (60°C), 5 (100'C) and 5 (16
0°C) satisfies the following formulas (1) and (2) at the same time.