JPH04194010A - Production of blended yarn having difference in elongations of filaments - Google Patents

Abstract

PURPOSE:To produce a blended yarn having an extremely large difference between the elongations of filaments by spinning a melted polymer through a spinneret having plural extrusion holes at different positions, the extrusion hole placed at the lower position having the cross sections continuously enlarged. CONSTITUTION:A polymer such as a thermoplastic polyester and/or polyamide is melt-spun through a spinneret to produce the objective blended yarn which is made of a single polymer and which is reduced in the breakage of the fiber when melt-spun. The spinneret has plural extrusion holes A, B placed at different positions, respectively, the extrusion hole B placed at the lower position having the continuously enlarged cross sections. The spinneret surface temperature of the extrusion hole having the continuously enlarged cross sections is preferably lower than the spinneret surface temperatures of other extrusion holes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a mixed fiber yarn having a difference in elongation, and more particularly to a method for manufacturing a spun mixed fiber yarn having a large difference in elongation.

[Conventional technology]

In recent years, so-called “new synthetic fibers” have been buzzing in the market.
Recent developments in materials have focused on attempts to bring out the characteristics of synthetic fibers, rather than imitating natural fibers. The content of the blended yarn also changes greatly accordingly, for example, a drawn blend is made by combining a low spinning speed undrawn yarn with an elongation of 250 to 350% and a medium spinning speed undrawn yarn with an elongation of 100 to 160%. This has also become corporatized.

Since this technology involves drawing and blending, there has been a demand for a more rational manufacturing method, that is, the development of a spun blend that can obtain such a large difference in elongation at the spinning stage.

As a technique for this purpose, for example, Japanese Patent Application No. 59-11439
Publication No. 9 describes that a special pin is used to extract a large difference in elongation.

Although this method provides a useful elongation difference, there are issues with production control, such as pin accuracy and stability during installation.Therefore, simpler methods, such as a simple cap without using a pin, are possible. A new technology was desired.

As methods that do not use pins, attempts have also been made to cool the spinneret or pack by protruding it, or by creating a difference in the protrusion between each hole within the spinneret surface, thereby increasing the elongation by creating a temperature difference within the spinneret surface. .

However, the reality is that with a mere cooling difference, not only the spinneret surface becomes cold and spinnability deteriorates, but also the important difference in elongation cannot be achieved much.

[Problems to be Solved by the Invention] The present invention consists of (1) a single polymer, (2) a sufficiently large difference in elongation;
- The purpose of the present invention is to provide a method for producing spun mixed fiber yarn that causes less yarn breakage during spinning.

[Means to solve the problem]

The present invention provides a method for obtaining a mixed fiber yarn using a spinneret having a plurality of discharge hole surfaces in which the positions of the discharge hole surfaces from which molten polymer is discharged are different. This is a method for producing a mixed fiber yarn having a difference in elongation, which is characterized by using a spinneret in which a discharge hole whose cross-sectional area at least continuously expands is installed on the discharge hole surface.

The present invention will be explained in detail below.

By lowering the polymer melt temperature or spinneret temperature,
The melt viscosity of the polymer discharged from the discharge hole increases,
It is known that the elongation stress increases and as a result, the elongation decreases even if the spinning speed is the same.

However, if the temperature is further lowered, the yarn will become weaker and eventually break, so if a normal discharge hole is used,
There were limitations in terms of the elongation and performance of the fibers obtained. Therefore, as a result of careful consideration of the direction in which the yarn is less likely to become weak even when the temperature is lowered, it was found that discharge holes with a larger hole diameter are less likely to cause the yarn to become weak.However, in this case, simply increasing the hole diameter However, there was a problem in that the back pressure of the polymer flowing in the discharge hole was insufficient, resulting in uneven discharge.

Therefore, as a result of further intensive study, the present inventors found that if a discharge hole with a continuously expanding cross-sectional area is used, it will be difficult to cause weak threads even when the mouth temperature is lowered, and the polymer flow within the discharge hole will be affected. It has been found that because the back pressure changes extremely smoothly and continuously, the polymer flow is stable and no uneven discharge occurs.

Furthermore, surprisingly, when the shape of the discharge hole is made into such a shape, the cross-sectional area at the point where the polymer leaves the discharge hole can also be made extremely large. It has become possible to spin high drafts of several thousand to 100,000 or more. Furthermore, since the temperature of the mouthpiece surface can be lowered, the draft effect can be taken out more effectively. Therefore, by spinning a blended yarn using a spinneret that has a main discharge hole with a low spindle surface temperature and another discharge hole with a high spindle surface temperature, it is possible to spin the mixed fiber yarn using only the spinneret without using complicated devices such as pins. This made it possible to produce a spun mixed fiber yarn with a sufficiently large difference in elongation.

The present invention will be explained in more detail below using the drawings.

FIG. 1 shows one embodiment of a spinneret that can be used in the present invention. The B hole is a discharge hole j whose cross-sectional area continuously expands, and its cross-sectional area continuously expands from the cross-sectional area SA at the end point 2 of the polymer introduction part l, and the molten polymer flows through the discharge hole. It has the characteristic that it reaches its maximum at point 3, where it leaves the spinneret, and this point is very different from the conventional spinneret (Figure 6).In other words, it squeezes at point 2, first applying a large back pressure, and then In other words, the discharge hole whose cross-sectional area continuously expands continuously expands to create a stable flow. For example, it also includes a case where the flow is expanded in stages without disturbing the laminar flow.

Next, in FIG. 1, the surface of the B hole from which the polymer is discharged needs to be located lower than the discharge hole surface of the A hole. This is to increase the viscosity by lowering the temperature of the polymer flow leaving the B hole than that of the polymer flow leaving the round hole, thereby making the effect of the spinning draft more effective and obtaining a large elongation difference.

Specifically, good results are obtained when the distance between the discharge hole surfaces is 3w or more, preferably 105w or more. However, L
If L becomes too large, for example, if L exceeds 100 m+, the temperature difference between the round hole and B hole will become too large, making it impossible to set an appropriate temperature condition. Therefore, a preferable result is obtained when L is up to about 70°. The temperature difference between the mouth surfaces depends on the distance between the discharge hole surfaces. A temperature difference between the mouth surfaces of 3°C or more, particularly 10°C or more gives preferable results. however,
If the temperature difference exceeds 40°C, stable spinning will not be possible, so the temperature difference is preferably 35°C or less.

In addition, as a method of controlling the temperature difference, there are methods such as installing a heater on the side surface of the mouthpiece or controlling the area around only the B hole group with a band heater.

In addition, in Figure 1, the specific cross-sectional area is the cross-sectional area S at point 3, which is 0,1962 kaku2 (round hole conversion!,=
1.01lllφ) or more is preferable, and 0.7850kaku2
(Round hole conversion i, *=2.O■φ) or more gives a more preferable result. In terms of the spinning draft, it is desirable that the cross-sectional area Sll be larger, but if it is too large, the number of discharge holes in one nozzle will be insufficient, so it is 19.625 m.
(round hole conversion p, = 10 mφ) is preferable from the viewpoint of obtaining a mixed fiber yarn with the same die. There are no restrictions when using multiple bases.

iA, 1. c and θ are not limited in any way as long as they satisfy the relationship Sa<S, for example! , is 0.10~0.90mφ,! , is 0.20~
About 15 aonφ is sufficient.

Also, θ is 5°〈θ〈45@, especially 10°〈θ〈30
° is sufficient.

Note that although the holes are round, this is not particularly limited, and various conventional discharge holes such as round holes and irregularly shaped holes can be used.

Although FIGS. 2 and 3 show other embodiments that can be used for manufacturing the mixed fiber yarn of the present invention, the present invention is not necessarily limited thereto.

Figure 4 shows the stress (St)-elongation (E curve (SS curve)) of the undrawn yarn of the mixed fiber yarn obtained using the spinneret of the present invention, in particular, the fine denier component has a low elongation. It is a combination of thick denier component and high elongation, for example, when the spinning speed is 1.000~
This is the SS curve of a mixed yarn drawn at a relatively low spinning speed of about 2,000 m/min, and shows the differences between low elongation (Eft) and high elongation (Eft).
), and the difference in elongation (Fl
2-Ef,) has an extremely large characteristic of 100% or more.

FIG. 5 is a stress elongation curve (SS curve) of an undrawn mixed yarn obtained using the spinneret of the present invention, in which the large denier component has a low elongation and the fine denier component has a low elongation. It can be seen that it is possible to have high elongation and exhibit behavior different from conventional spun mixed fibers.

Figure 6 shows a schematic percentage formula of a conventionally studied spinneret. Figure 7 shows a stress-elongation curve (
SS curve) is shown. In this case, the fine denier component has a low elongation, but the difference in elongation from the thick denier component is small, and even when wound at a low spinning speed, the elongation is at most about 85%.

The mixed fiber yarn obtained by the method of the present invention is subjected to drawing heat treatment if necessary, and used as raw yarn for various woven and knitted fabrics. The stretching heat treatment conditions are not particularly limited, and existing equipment,
Existing conditions can be used. Further, this method can be either a so-called separate stretching method in which the material is wound once and then subjected to a heat treatment for stretching separately, or a so-called direct stretching method in which a spinning and stretching heat treatment is performed continuously.

Also, as is commonly known, high spinning speeds, e.g. 4,0
In the case of 00 m/min or more, the mechanical properties are improved, so there is no need to carry out the stretching heat treatment.

Furthermore, the mixed fiber yarn of the present invention can be used not only as a drawn yarn but also as a textured yarn by being subjected to a false twisting process.

Furthermore, the single yarn denier and total denier of the product are not particularly limited.

Note that the molten polymer used in the present invention includes thermoplastic polyester and/or polyamide. Examples of the thermoplastic polyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate, and examples of the polyamide include nylon 61, nylon 66, and nylon 46.

Further, in the present invention, a spun mixed fiber yarn having a large difference in elongation can be produced in the above manner. Here, the elongation difference differs greatly depending on the combination of deniers constituting the mixed fiber yarn or the winding speed, but the elongation difference aimed at in the present invention means, for example, when a fine denier component has a low elongation. , spinning speed 1,000~
At a low spinning speed of 1,500 m/min, there is a difference in elongation of at least 100%, and even at a medium spinning speed of 3,000 m/min, there is a large elongation difference of at least 30%. This also includes cases where the elongation of the fine denier component is smaller than that of the fine denier component, which changes the concept of conventional spinning and mixed fibers.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, in this example, the physical properties were measured by the following method.

(2) Intrinsic viscosity Calculated from the melt viscosity measured using an Ostwald viscometer in orthochlorophenol at 35°C.

■ Ratio of spinning draft winding speed (V) to polymer discharge speed (T) (V
/T).

■Case surface temperature A detection end was inserted into the discharge hole surface, and the surface temperature was measured.

■ Tensile strength (S t ) and elongation (E) of the blended yarn Using an autograph (constant speed extension type tensile tester), the grip distance was set to 20 cm, and the sample was attached under the standard initial load.
The sample was pulled at a tensile rate of 100%/min, a load-elongation curve was drawn, and the maximum stress point on the back-elongation curve was taken as the cutting strength and elongation of the sample.

In addition, the number of measurements was 5 times and the average value was obtained.
) was defined as strength (g/d) by determining the strength per fineness.

■ A skein of bulky yarn (circumference: 1.25 m) was rotated 320 times, a load of 6 g was hung from one end of the sample folded in half, and the sample was dry heated at 180°C for 5 minutes. After cooling, a constant weight ( The deposition (Vcj) of Wg) was measured under a load of 6.4 g, and calculated using the following formula.

(2) Dyeability and Texture The obtained mixed fiber yarn was knitted in a tube, dyed under normal pressure with a disperse dye, washed with water, dried, and then set at 180° C. for 1 minute to prepare a sample for evaluation.

Evaluation was performed visually and tactilely.

Example 1 Polyethylene terephthalate having an intrinsic viscosity [η] of 0.64 (containing 0.07% by weight of T i Ot as a quenching agent) was melted and a spinneret having the combination of discharge shapes shown in FIG. The number of holes in each of A and B was 12H), and extrusion was performed at a discharge rate of 14.7 g/min. Here, the dimensions of each part of the discharge hole used and the dimensions of the nozzle are determined as follows.
Shown in the table.

Table 1 The extruded polymer stream has a temperature of 26°C and a humidity of 60%.
After cooling and solidifying by blowing cooling air at a linear velocity of 30 C11/sec, oil was applied with an oiling roller and wound at a take-up speed of 1,000 m/min to form a 133 denier/
A multifilament of 24 filaments was obtained. In addition,
The ratio of the fine denier component and the thick denier component constituting the mixed fiber yarn at this time was about 1:3, and the fine denier component had a low elongation.

From the stress-elongation curve of the obtained undrawn yarn, the elongation difference (EI!,
tEj! +) are shown in Table 2.

As is clear from Table 2, the difference in elongation is extremely large, and as shown in Figure 4, it is as if the undrawn yarn wound at a low spinning speed and the undrawn yarn wound at a medium spinning speed were mixed together. SS
It had a curved shape.

Subsequently, this unstretched system was subjected to stretching heat treatment under the following conditions,
A drawn yarn of 51 denier/24 filaments was obtained.

(Stretching Conditions) The obtained drawn yarn had extremely high bulkiness of 51c1ff/g.

Next, the multifilament was knitted into a tube and dyed with a disperse dye under the following conditions.

(Staining conditions) After washing and drying the dyed sample, it was heat set at 180° C. for 1 minute.

The sample thus obtained was uniform and had good dyeability, and had a bulky texture.

Examples 2 to 6 Polyethylene terephthalate with an intrinsic viscosity [η] of 0.72 (contains 0.07% by weight of Ti1t as a matting agent)
was melted, and a mixed fiber yarn of 92 denier/24 filaments was obtained using the die used in Example 1 in the same manner as in Example 1. Note that this experiment was carried out by changing the discharge amount and spinning speed.

Table 3 shows the spinning conditions and the elongation of the obtained mixed fiber yarn.

Note that the fine denier component of the mixed fiber yarn had low elongation and the denier ratio was 1:3.

As shown in Table 3, the elongation difference itself was large at low spinning speeds, but even at medium spinning speeds of 3000 m/min, there was a 60% difference in elongation.

(The following is a blank space) Comparative Example 1 A mixed fiber yarn of 133 denier/24 filaments was obtained by carrying out the same procedure as in Example 1 except that the spinneret was the combination shown in FIG. 6. As the temperature in hole group B decreased, the flow rate decreased and the yarn became a mixed fiber yarn.

The denier ratio of the components constituting the mixed fiber yarn at this time was 1:3, and the fine denier had a low elongation.

The dimensions of each part of the die used and the elongation of the undrawn yarn are shown in Tables 4 and 5, respectively.

As is clear from Table 4 and Table 5, even at low spinning speeds, the difference in elongation was only about 85%.

This undrawn yarn was drawn 3.2 times in the same manner as in Example 1,
A drawn yarn of 42 denier/24 filaments was obtained. Its bulkiness was as low as 1 Bcd/g.

Comparative Example 2 With the same type of discharge hole combination used in Comparative Example 1,
The A hole is the same as Comparative Example 1, and the B hole is! □=fs+=5
．． Spinning was carried out in the same manner as in Example 1 using a spinneret of Omφ, 1cI=1.2EISL=60. The discharge spot in hole B was thick (could not be wound up).

Example 7 With the same type of discharge hole combination used in Example 1, the sixth
Using a spinneret with the dimensions shown in the table, spinning was carried out in the same manner as in Example 1 to obtain a mixed fiber yarn of 133 denier/24 filaments. The denier ratio of the components constituting the mixed fiber yarn at this time was 1:2, and the thick denier component had low elongation. The elongation of the mixed yarn is also listed in Table 6.

Table 6 In this example, the thick denier component has low elongation.
A blended yarn different from conventional spun blended yarns was obtained.

〔Effect of the invention〕

According to the method of the present invention, even if the spinneret temperature and the spinning temperature are lowered, the yarn is less likely to become weak, and the yarn is less likely to become weak than the conventional spinning draft.
Since it is possible to apply a spinning draft that is more than an order of magnitude larger, or even two orders of magnitude larger in some cases, it is possible to obtain a blended yarn with an extremely large difference in elongation, and in addition, the elongation of the thick denier component and the elongation of the fine denier component can be improved. By reversing the above, it has become possible to create an innovative blended yarn in which the high denier component has low elongation, which is of great industrial significance.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of a spinneret having a discharge hole in which the discharge hole surface is located at the bottom and the cross-sectional area of the discharge hole continuously increases, which can be used for manufacturing the mixed fiber yarn of the present invention. show. 2 and 3 show other embodiments of the spinneret that can be used in the production method of the present invention, FIG. 2 shows a case in which the cross-sectional area of the A hole decreases continuously, and FIG. 3 shows a case in which the cross-sectional area of the A hole decreases continuously. This shows the case in which is continuously expanded. Figure 4 shows the stress (St) of the mixed yarn obtained by the method of the present invention.
) - Elongation (Ell curve), especially when the fine denier component has low elongation. Figure 5 shows the stress (St) of the mixed fiber yarn obtained by the method of the present invention.
)-elongation (EI2) curve, which particularly shows the case where the thick denier component has low elongation. Figure 6 shows a schematic diagram of a spinneret that has been studied in the past. Figure 7 shows the stress (S
t) - Elongation (E curve is shown. In the figure, 1.1' is the introduction part of the polymer, 2.2' is the point where the introduction part ends, and 3,3' is the point where the cross-sectional area of the discharge hole is maximum. point, 'AI+ i, A2 and f III, ff
i B2 indicates the diameter at points 2.2' and 3.3', respectively. ff1c++ IcZ are the distances of 2 to 3 and 2' to 3', respectively, and L is the distance between the discharge surfaces of the discharge holes A and B. Patent Applicant Teijin Co., Ltd. Agent Patent Attorney Shige Takashi Shirai Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (4)

[Claims] (1) In a method for obtaining a mixed yarn using a spinneret having a plurality of discharge hole surfaces in which molten polymer is discharged from different positions, the discharge hole is located at the lower part of the plurality of discharge hole surfaces. A method for producing a mixed fiber yarn having a difference in elongation, the method comprising using a spinneret in which a discharge hole whose cross-sectional area at least continuously expands is installed on the hole surface. (2) The method for producing a mixed fiber yarn having a difference in elongation according to claim 1, wherein the temperature of the mouth surface of the discharge hole whose cross-sectional area continuously increases is lower than the temperature of the mouth surface of other different discharge holes. (3) The method for producing a mixed fiber yarn having a difference in elongation according to claim 1, wherein the maximum cross-sectional area of the discharge hole whose cross-sectional area continuously increases is at least 0.1962 mm^2. (4) The method for producing a mixed fiber yarn having a difference in elongation according to claim 1, wherein the molten polymer is a thermoplastic polyester and/or a polyamide.