JPS5936687B2 - How to relax synthetic fibers under tension - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention efficiently relaxes the synthetic fibers under tension when producing synthetic fibers such as polyamide fibers and polyethylene terephthalate fibers by the direct spinning/drawing method to create low shrinkage yarns or low shrinkage yarns. The present invention relates to a method for producing a shrinkable and highly elongated yarn.

Conventionally, as a method for industrially obtaining low-shrinkage yarns or low-shrinkage and high-elongation yarns made of synthetic fibers such as polyamide fibers and polyethylene terephthalate fibers, the method consisted of a heated drawing roller and a cold relaxation roller. There is a method using a relaxation device.

In the production of low-shrinkage yarn using this relaxation method, the stretched fibers in a tensioned state that are drawn out from a heated drawing roller (hereinafter referred to as the drawing roller) are not completely heat-set and are produced by drawing. There is residual strain in the fibers, and when the tension is released, the fibers show a physical change in which they contract.

As a means to minimize the residual strain of the fibers, or to alleviate the strain, the temperature of the stretching roller can be increased, the relaxation rate can be increased, and the stretching roller and the cold relaxation roller (hereinafter referred to as the relaxation roller) can be ) is characterized in that the tension of the loosened yarn is lowered to relax the yarn, and then a loosening roller is used to prevent dimensional changes in the yarn after relaxation so as not to reduce the effect of the relaxation. method is known.

Therefore, raising the temperature of the stretching roller and lowering the tension of the relaxed yarn between the stretching roller and the relaxing roller are essential conditions for obtaining a low-shrinkage yarn.

However, when the conventional relaxation method described above is applied to the direct spinning drawing method in which the yarn is drawn out from the drawing roller at a high speed of 1500 m/πin or more, if the tension of the relaxed yarn is made too low, the relaxation roller When the threads are wound around each other, adjacent threads overlap each other, causing disturbances in the threads (hereinafter simply referred to as "disturbances in the threads"), making it difficult to draw and reducing the target low-shrinkage yarn. cannot be manufactured efficiently.

If you are trying to obtain the target low shrinkage yarn, you may need to significantly reduce the yarn processing speed or increase the drawing roller temperature to a very high temperature to further heat set the fibers under extremely high tension. However, it is not possible to manufacture the fiber at a low cost because it is extremely inefficient, such as by using a method such as "doing it", or involves frequent process troubles such as thread breakage and equipment failure during fiber production.

Therefore, when low-shrinkage yarns are produced industrially and inexpensively by the direct spinning/drawing method, not only is productivity lowered, but there is also a natural limit to the desired low-shrinkage properties.

Furthermore, when producing a yarn with low shrinkage and high elongation, in addition to the same stretching conditions, it is necessary to use conditions with a low stretching ratio, resulting in the above-mentioned problems.

Therefore, the inventors of the present invention conducted intensive studies to prevent the yarn from being disturbed in the above-mentioned relaxation roller and to obtain synthetic fibers with low shrinkage or low shrinkage and high elongation at high speed. The disturbance is caused not only by a decrease in the tension of the relaxed yarn, but also by spinning factors such as increasing the yarn speed, which causes the tension between the stretching roller and especially the yarn wound around the relaxing roller and the roller. The contact area and contact time are reduced, and the adhesion of the yarn to the roller surface is reduced.Furthermore, while the yarn is guided to the relaxation roller and wound, the relaxation roller is cold (,sQ-
Because it is a rubber yarn, it does not have the function of actively shrinking the yarn, and the yarn tension does not increase due to the contraction of the yarn. It was concluded that unless these problems were solved, it would be impossible to industrially produce synthetic fibers with low shrinkage or low shrinkage and high elongation at low cost. As a result, the present invention has been achieved.

Therefore, an object of the present invention is to provide a method for producing low-shrinkage or low-shrinkage and high-elongation synthetic fibers at high speed and at low cost.

15Q0771 from the heated stretching roller
A roller rotating at a circumferential speed (2) smaller than the circumferential speed (1) of the drawing roll, and which rotates the drawn synthetic fiber thread drawn out at a speed of /'man or more at a circumferential speed (2), and
a roller having a surface temperature of ~140°C and a surface temperature at least 45°C lower than the surface temperature of said stretching roller (
When relaxing synthetic fibers in tension by guiding them to a relaxation roller, the yarn (relaxed yarn) running between the stretching roller and the relaxation roller is brought into contact with a convergence guide, and the relaxed yarn is Below (1), (2) and (3)
This is achieved by applying a tension that simultaneously satisfies the conditions of Eq.

0.02≦T≦0.30 (
1) 1.03≦TI/TO≦6 (2) 0.8628 0.4483<T, /T,
≦ 1.28(3) To・15−T However, in the above equations (1), (2) and (3),
To is the tension (g/denier) of the yarn running between the drawing roller and the guide in the relaxed yarn; T1 is the tension (g/denier) of the yarn running between the guide and the relaxing roller in the relaxed yarn; The tension of the yarn (g (denier)) and T are the tension of the relaxed yarn (g (denier) /denier) The range of tension ratio (T, /To) and tension (T) that simultaneously satisfies the above formulas (1), (2), and (3) is as follows:
In the graph (Figure 1) shown by selecting T1/To as the vertical axis and T as the horizontal axis, point A (0,02,6,00
).

B(0,02,1,55), C(0,30,1,03
).

D(0,30,1,91) and D(0,30,1,91
) and E(0,115,6,00) are sequentially and cyclically connected with straight lines.

Preferably points A'(0,03,5,00), B'(0,
03,2,50), C'(0,25,1,10),D'
(0,25,2,00) and E'(0,12,4,,8
0) in the same way.

Further, the method of the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 2 shows the relaxing method of the present invention, in which the relaxed yarn 2z, which has an extremely low tension and is derived from the heated drawing rollers 1 and 1', is connected to the drawing rollers 1 and 1'. By running in contact with the guides 4, 4' provided between the rollers 3, 3', the winding is carried out extremely stably on the relaxing rollers 3, 3' with little vibration and no single yarn breakage, and finally the winding is carried out. When wound on a machine (not shown), it is possible to stably produce yarn with low shrinkage or low shrinkage and high elongation at high speed.

The heated drawing roller has a circumferential speed (■1) of 1500 m/1, which is a unique high speed for the direct spinning/drawing method.
It means a roller that rotates at m1f1 or more and whose surface temperature is heated to 125°C or more, preferably 150°C or more, and a cold relaxation roller is equipped with a heating means but is not heated. , or does not include a heating means, or has an active cooling means, and the peripheral surface velocity (
■1) means a roller with a smaller circumferential speed (■2).

The surface temperature of the previously defined cold relaxation roller when relaxation is actually taking place is the total denier of the yarn to be relaxed (
There may be some differences depending on conditions such as the surface temperature of the drawing roller (usually 120 to 250°C), the time the yarn stays in the relaxation roller zone (usually 0.1 to 1.4 seconds), etc. , in the range of 40 to 140°C as described above, and the surface temperature of the relaxing roller is at least 45°C lower than the surface temperature of the stretching roller, and under the above conditions, the surface temperature of the relaxing roller is the lowest. This refers to the temperature difference between the surface temperature of the roller where the yarn is first wound around the relaxation roller and the surface temperature of the stretching roller.

The temperature at the part where the yarn is introduced into the relaxation roller (inlet part) is about 1 1 lower than the temperature at the part where the yarn leaves last (exit part).
The temperature gradient becomes high by 0 to 60° C. and decreases as it approaches the exit portion.

Next, the effects and functions of the guides 4, 4' described above will be described.

The guides 4, 4' are composed of two guides that can suitably relax the yarn when the tension T of the relaxed yarn is 0.10 g/denier or less. 2 is shown in FIG. 3. z (Yarn 2 means a yarn that runs between a drawing roller and a guide, and Yarn 2 means a yarn that runs between a guide and a relaxation roller, respectively) and guides 4 and 4' by arrow I. The yarn is focused by running in contact with the four smooth parts as shown in the enlarged view seen from the direction of -H, and by adjusting the angle of contact with the yarn guide, surface roughness, etc., appropriate frictional resistance can be achieved. is applied, the tension of the yarn 2 is increased, and the yarn 2 changes from a slack state to a tense state, and the yarn 2 moves around the relaxation rollers 3 and 3' without shaking or unraveling the single yarns that make up the yarn. The surface can be wound stably.

The guide (hereinafter referred to as "guide") is a focusing guide, and must have the function of focusing loose threads and increasing the tension of the threads led out from the focusing guide.

The shapes of this guide shown in FIGS. 2, 3, 6, and 7 can be suitably used.

Focusing if necessary: Although the effect is small, it is also possible to use a plurality of cylindrical guides arranged in a row as shown in FIG.

However, the guide and usage without a focusing function as shown in FIGS. 4-A and 4-B cannot be applied.

In the above, by providing a guide, the tension T of the yarn introduced from the guide is increased, whereas the tension T of the yarn introduced into the guide is increased.

However, surprisingly, by adjusting the tension of the present invention, problems such as reverse winding of the yarn around the drawing roller do not occur. .

That is, the yarn becomes slack after it leaves the drawing roller 1.1', and although the yarn moves slightly unstable, it is held by the drawing rollers 1, 1'. The effect also helps to limit the lateral movement of the yarn, and on top of that, the guy:
The movement is very effectively stopped by the
Since the stretching rollers 1 and 1' are heated rollers, the single yarns constituting the yarn are uniformly contracted, although the tension is low, and the reverse winding on the stretching rollers 1 and 1', especially the stretching roller 1, is prevented. This is due to the fact that the surface of the stretching roller is rough.

However, if the tension condition of the loose yarn of the present invention is exceeded, for example, if the yarn tension T is less than 0.02 g/denier, the yarn tension To of the loose yarn will be extremely reduced due to friction with the guide, as described above. A reverse winding phenomenon occurs, and thread breakage occurs frequently.

On the other hand, if the yarn tension T exceeds 0.30 g/denier, the disorder of the yarn becomes small, the guiding effect disappears, and synthetic fibers with low shrinkage cannot be obtained.

If the tension ratio T1/To exceeds the upper limit of the range of the present invention, reverse winding phenomenon occurs frequently, wear of the guide, decrease in strength, and increase in yarn breakage occur.

Furthermore, if the tension ratio Tt/To is outside the lower range of the above range, the frictional resistance between the yarn and the guide is small and the yarn tension cannot be adjusted to an extent that prevents the yarn from becoming disordered.

Next, the conditions and method for using the guide will be described.

The conditions or method for using the guide are determined depending on the material of the yarn to be loosened, the type of yarn, and the target quality for yarn convergence and tension adjustment.

A fixed type guide is preferable from the viewpoint of preventing yarn disturbance and operational control, but a rotating type guide may be used alone or in combination with a fixed type guide, if necessary.

It is preferable to install the guide between the stretching roller and the relaxation roller to prevent the yarn from becoming disordered (this is effective, operational management, and safety reasons), but the guide may be wound around the stretching roller if necessary. The final yarn may be run in contact with the first yarn wound around the relaxation roller.

The guide has a radius of curvature (R in Figure 7-B), an inner diameter (D in Figure 7-A), and a total denier of the yarn to be processed so that the yarn will not be damaged by friction due to contact with the guide. and must be appropriately selected depending on the tension.

Further, the guide must be made of a material with excellent wear resistance such as titanium oxide or ceramic coating, and must have a surface treated to have a somewhat rough surface without sharp protrusions that will not damage the yarn.

In particular, as soon as the guide surface begins to wear and seize, it causes a decrease in the strength of the fibers obtained and an increase in fuzz.

Furthermore, a structure may be used in which oil or the like oozes out from the guide and is applied to the yarn.

Although various structures, methods of use, and methods of adjusting the contact state between the yarn and the guide can be considered for the guide included in the relaxation method of the present invention, by providing a guide having the above-mentioned functions, it is possible to It is now possible to relax the yarn under conditions of high speed and low tension, which was previously not possible, and it is possible to directly connect low-shrinkage yarns made of synthetic fibers such as polyamide fibers and polyethylene terephthalate fibers, or low-shrinkage and high-elongation yarns. By the spinning/drawing method, it can be produced industrially at low cost and at high speed with almost no yarn disorder.

Examples of the present invention will be described below.

Examples 1 to 14, Comparative Examples 1 to 10 Using a polyethylene terephthalate raw material with an intrinsic viscosity of 0.85 measured by a well-known method in a 0-chlorophenol solution at 25°C, filaments suitable for fishing nets of 1000 De/96 fil ( Strength 6g/denier, cutting elongation 2
8% and dry heat shrinkage rate of 4%), the fibers were directly spun and drawn under the following conditions, and various studies were conducted on the guide and tension conditions configured in the relaxation method of the present invention, and the obtained results are shown in Table 1. Shown below.

Spinning machine: Extruder type melt spinning machine Spinning temperature: 300°C Spinneret: Number of holes: 96, hole diameter: 0.6 mmφ Stretching speed = 2000-3500rrL/min Stretching ratio: 3.6-4.2 times Stretching roller temperature: 210 °C Relaxation rate: 1 to 6% As is clear from the example shown in Table 1, when the tensioned yarn stretched under the tension conditions of the present invention is relaxed, the yarn becomes almost completely disordered, and the guide It has become possible to stably obtain a low shrinkage and high elongation yarn suitable for fishing nets at high speed and without any abrasion or decrease in the strength of the resulting fibers.

Note that the symbols indicating yarn disorder in the table have the following meanings.

×: When the yarn wobble is 5 mm or more, the yarn is extremely disordered, the yarns overlap each other, and it becomes difficult to draw and wind the yarn.

Furthermore, if T1/T□ is increased in order to prevent the yarn from becoming disordered, the strength of the yarn will be greatly reduced due to wear of the guide.

△...The yarn sway is about 3m711, and stable operation is just a step away.

The guides will wear out, but it can be countered by updating the guides more quickly.

The low shrinkage of the resulting fibers is quite normal.

○: Preferably, stable operation is possible and fibers with excellent low shrinkage properties are obtained.

◎・・・Extremely good and stable operation is possible, and fibers with ultra-low shrinkage can be obtained.

Moreover, the yarn sway is a value calculated using the following formula.

Yarn fluctuation (mu) = distance traveled by the yarn in the direction perpendicular to the roller axis (1111'/L) - system (in) The quality of the drawn yarn was measured by the following method.

Strength ~ JIS L 1013 (1981) Elongation ~ Same as above Dry heat shrinkage rate ~ The yarn was treated in air at 150°C for 30 minutes, and the initial length l.

Measure the length right after treatment, 13o-11/11oX 100 = Dry heat shrinkage rate (%)
And so.

The yarn speed means the circumferential speed (■1) of the drawing roller.

The tension of the yarn was measured as follows.

The measuring device is TENSION TERHF- manufactured by Eiko Sangyo.
2000 type, the tension T of the relaxed yarn when the guide between the stretching roller and the relaxing roller is removed is measured at a position approximately halfway between the rollers, and the tension T when the guide between the rollers is provided is measured at a position approximately halfway between the rollers. The tension T of the yarn before it enters the guide.

and the tension T1 of the yarn exiting the guide were measured separately but not at the same time.

The yarn tensions T, To, and T1 measured by the above method are in g (duram), but the conversion to g/denier was calculated by dividing by the total denier of the yarn at the tension measurement point.

Example 15 Polyethylene terephthalate with an intrinsic viscosity [0.68] was directly spun and drawn under the following conditions to obtain 1100 De/192 f.
A study was conducted to understand the relationship between the relaxation conditions for obtaining a low-shrinkage filament of il, the dry heat shrinkage rate of the obtained filament, and the disorder of the yarn on the relaxation roller, and the results shown in Table 2 were obtained.

Spinning machine: Extruder type melt spinning machine Spinning temperature -290°C Spinneret: Number of holes 192, hole diameter 0.6 mmφ Stretching roller temperature = 210-230°C Stretching, circumference of roller: 1200-3500 m/min Surface speed of relaxation roller Table: Unheated surface temperature relaxation rate: 3-10% Guide: Material is titanium oxide.

Curvature radius R = 2.5 cage.

Inner diameter D = 12 mm φ.

The angle of contact with the yarn guide is 0 to 145°.

As is clear from the examples shown in Table 2, by employing the relaxation method of the present invention, it is possible to relax the yarn with almost no yarn disturbance at high speed and under low tension conditions. This makes it possible to stably produce low-shrinkage yarn at high speed, which was previously impossible.

Example 16 Nylon 6 having a relative viscosity of 2.37 obtained by the sulfuric acid method was directly spun and drawn under the following conditions to obtain a fiber with high strength and low shrinkage.

Spinning machine: Extruder type melt spinning machine Spinning temperature: 280°C Spinneret: Number of holes 204, hole diameter 0.4 mmφ Stretching roller temperature = 180°C Relaxing roller temperature: 120°C Circumference of stretching roller: 3200 m / min surface speed drawing Magnification: 5.3 times Relaxation rate = 14% Thread tension T: 0.03 g/d T/To: 2.40 As a result, the tension in the system during operation was 2.3 mm, and the yarn sway was 1.
711t11L, the number of yarn breakages was 71 tons twice, and stable operation was possible.

The obtained fiber has a tenacity of 9.3 g/d, an elongation of 31%, and a boiling water shrinkage rate (fiber treated in boiling water for 30 minutes) of 6%, which shows high strength and excellent low shrinkage. Ta.

[Brief explanation of the drawing]

FIG. 1 shows the above-mentioned formulas (1) and (2
) and (3) are shown in a graph, FIG. 2 is a process diagram showing the relaxation method of the present invention, and FIG. It is an enlarged view seen from method H. FIG. 4-A is a diagram showing the state of the guide and yarn that is not applied to the present invention. FIG. 4-B is a view seen from the direction of yarn Y. 7A, 7B, 5 and 6 are a front view and a side view of a typical guide applied to the present invention. 1.1': Stretching roller, 2. z: Yarn, 3, 3': Relaxation roller, 4, 4' guide, 5, 6, 7, 8 guide,
Y, Y': Yarn.

Claims (1)

[Claims] 1 1500 m 1 m1n from heated stretching roller
The drawn synthetic fiber yarn drawn at a speed of
Peripheral speed ■2 smaller than peripheral surface speed V1 of the stretching roll
a roller (relaxation roller) that rotates at
When relaxing the synthetic fibers in a tensioned state by guiding the fibers to the stretching roller, the yarn (relaxed yarn) running between the stretching roller and the relaxing roller is brought into contact with a convergence guide, and the following (1) is applied to the relaxed yarn. ), (2) and (3) A method for relaxing synthetic fibers in a state of tension, characterized by applying tension that satisfies the conditions of formulas (2) and (3) at the same time. 0.02≦T≦0.30 (1
)1.03≦T s / T o≦6 (2) 0.862
8 0.4483≦T, /To□
(3) TO・15T1・20 However, in the above formulas (1), (2) and (3),
To is the tension (g/denier) of the yarn running between the drawing roller and the guide in the relaxed yarn; T1 is the tension (g/denier) of the yarn running between the guide and the relaxing roller in the relaxed yarn; The tension of the yarn (g/denier) to Denier)