JPS62110913A - Production of combined filament yarn of different shrinkage - Google Patents

Abstract

PURPOSE:To efficiently obtain a thermally stable combined filament yarn of different shrinkage without causing loops or yarn unevenness, by melt spinning a polyester filaments, dividing the resultant filaments into two filament yarn groups, giving a spinning tension difference, separately collecting the yarns, doubling the yarns, heat-treating and winding the resultant doubled yarn. CONSTITUTION:Two filament yarn groups (A) and (B) are separately collected to give >=0.2g/denier spinning tension difference. The spinning tension of the yarn group (A) is adjusted to <=0.6g/denier and the spinning tension of the yarn group (B) is adjusted to >=0.7g/denier. The yarn groups (A) and (B) are doubled in an interlacer 5, heat-treated at a temperature 70-150 deg.C lower than the melting point of the polyester with a heated roll 7 and then wound at >=4,000m/min speed.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for producing a differentially shrinkable mixed fiber yarn, and more specifically, the present invention relates to a method for producing a differentially shrinkable mixed yarn in a high-speed spinning method using a difference in spinning tension. The present invention relates to a method of manufacturing yarn.

(Prior art) In order to produce a differentially shrinkable mixed fiber multifilament composed of a plurality of yarn groups with different heat shrinkage rates, separately spun yarn groups are drawn in the same way under different heat treatment conditions. Generally, a method is adopted in which the yarn is stretched using a machine, then the yarn is doubled and rolled up into one package. However, this method has the disadvantage that the process is complicated and the manufacturing cost is high.

In addition, as an example of a manufacturing process that simplifies the process, Japanese Patent Application Laid-Open No. 2002-2013 (Sho) discloses a method of manufacturing differentially shrinkable mixed fiber multifilament using only the spinning process by spinning yarns with different finenesses at a high speed of 3,000 m/min or more. This is proposed in Japanese Patent No. 51-130315. However, in this method, in order to increase the difference in heat shrinkage rate, it is necessary to make the difference in single yarn fineness extremely large or to increase the difference in spinning speed. Moreover, when attempting to provide a difference in heat shrinkage rate by utilizing the difference in single yarn fineness, there is a drawback that the thick fineness yarn tends to become loose, resulting in frequent occurrence of loops and the like in the package taken up. Furthermore, Japanese Patent Publication No. 54-
No. 147216 discloses that one yarn group is not drawn.

There are 12 methods of heating and drawing other yarn groups, but methods that attempt to impart a difference in heat shrinkage rate using means such as spinning speed differences or the presence or absence of heat treatment are difficult to achieve due to equipment considerations. It is extremely uneconomical and unsuitable for industrial production.

On the other hand, JP-A-55-158316 discloses a method of applying an oil agent at different positions for large and fine filament groups in order to eliminate the walnuts caused by the difference in fineness mentioned above. Since the oil agent application position of the filament group is lower than that of the fineness group, there is no big difference in the spinning tension per denier between the two, and therefore it is possible to obtain a differentially shrinkable mixed fiber yarn with a sufficiently large difference in heat shrinkage rate. I couldn't.

Further, U.S. Patent No. 4,246,747 describes a method for producing a differentially shrinkable mixed fiber yarn by changing the oiling agent application position. Due to the high speed, it can easily cause thread spots and is difficult to apply to multi-thread systems.

There was a problem that it was disadvantageous in terms of cost.

Furthermore, JP-A-56-1401) 4 discloses a method of changing the focusing position of two groups of filaments in order to obtain a differentially shrinkable mixed fiber yarn with fineness. Since it is regulated only at the focusing position, the range in which the heat shrinkage rate can be adjusted is limited at high speeds, and it also has the disadvantages of being thermally unstable and having problems in terms of 9 strength elongation as it is not heat treated. are doing.

(Problems to be Solved by the Invention) As mentioned above, various methods have been proposed to obtain differential shrinkage mixed fiber yarns by high-speed spinning and blending methods, but in all of these methods, many loops occur in the package. However, it has the disadvantages of causing thread spots and being thermally unstable.

The present invention provides a differentially shrinkable mixed fiber yarn that does not have the above-mentioned drawbacks.

A technical object of the present invention is to provide a method for producing differentially shrinkable mixed fiber yarn that can be efficiently produced by a high-speed spinning mixed fiber method.

(Means for Solving the Problems) That is, in the present invention, polyester fibers are melt-spun and divided into 82 yarn groups, and the spinning tension of yarn A is 0.6.
g/d or less, the spinning tension of yarn group B is 0.7 g/d or more, and the difference in spinning tension between both yarn groups is 0.2 g/d or more. After doubling yarn group A and yarn group B and taking them to the same take-up roller, they are heat-treated at a temperature 70 to 150°C lower than the melting point of polyester, and then
The gist of this invention is a method for producing a differentially shrinkable mixed fiber yarn, which is characterized by winding at a speed of ,000 m/mm or more.

Hereinafter, five aspects of the present invention will be explained in detail.

In the present invention, first, polyester fibers are melt-spun to form A, 8
The yarn is divided into two groups, and the yarn groups A and B are cooled and bundled separately so that the spinning tensions of the yarn groups A and B are different.

The reason why the spinning tension is different is to make the molecular orientation of both yarns A and B different, and the spinning tension for one yarn group A is 0.6 g/d or less, which is the normal high-speed spinning condition.

Preferably 0.5 g/d or less, yarn group B is 0.7 g/d
Above, preferably 0.8 g/d or more, and the spinning tension difference between both yarn groups is 0.2 g/d or more, preferably 0.3
8/d or more.

Next, yarn groups A are separately bundled with different spinning tensions.
, B with the same take-up roller, the temperature is 70 to 150'C below the melting point (Tm) of polyester during the process up to winding up.
It is necessary to heat treat at a low temperature. This heat treatment crystallizes the polyester fibers, and the heat treatment temperature is important because it affects the heat shrinkage rate and strength/elongation properties. That is, when the heat treatment temperature is lower than Tm -150°C, there is a drawback that crystallization progresses less and the strength is low and the elongation is high.

Furthermore, since the shrinkage stress of yarn group B, which has a high spinning tension, is too large, a problem arises in that the paper tube is difficult to remove from the winding machine. On the other hand, when the temperature is higher than Tm-70°C, crystallization progresses too much in both yarn groups^ and B.

This is not preferable because there is no difference in heat shrinkage rate.

In the present invention, after heat treating yarn groups A and B,
It is necessary to wind it up at a speed of m/min or higher. If the winding speed is slower than 4000 m/min, 0.7
It is difficult to apply a spinning tension of more than 0.7 g/d, and even if the spinning tension is 0.7 g/d or more, the spinning tension is 4000 m/m
If there is no in-groove, there will be no difference in the degree of molecular orientation between both yarn groups A and B, which is not preferable.

According to the method of the present invention as described above, it is possible to produce a mixed shrinkage yarn in which the yarn group A has a low orientation and a low heat shrinkage rate, and the yarn group B has a high orientation and a high heat shrinkage rate. The difference in heat shrinkage rate between yarn groups A and B can be adjusted by adjusting the spinning tension difference, heat treatment temperature, etc., but the difference in heat shrinkage rate between them should be 5% or more, preferably 8% or more. is necessary.

As described above, according to the present invention, the melt-spun yarn group A
, B can be produced by a simple process of varying the spinning tension of B to give a difference in molecular orientation, followed by heat treatment and crystallization.

In addition, since the same heat treatment is applied after yarn groups A and B are combined, the adjustment range of heat shrinkage is wide. Furthermore, since a stretching process is not required, it can be manufactured efficiently without providing a special roller or changing the roller diameter.

As the polyester in the present invention, polyethylene terephthalate obtained by a known polymerization method is typically mentioned. It may also be a polyester obtained by mixing or copolymerizing. Yarn group A,
The fineness of B is also not particularly limited, but the 4i yarn fineness is preferably 0.5 to 10 deniers, particularly 1 to 7 deniers, and the total fineness is 20 to 300 deniers, especially 3
0 to 180 deniers are preferred.

Moreover, the yarn group A and the yarn group B do not necessarily have to have the same cross-sectional shape, the same single yarn fineness, or the same total fineness, and may be different from each other.

In the present invention, as a means for adjusting the spinning tension of the yarn groups A and 1, for example, there is a method of moving the convergence position of the yarn groups A and B. This is because the spun yarns are cooled and solidified and run at high speed, which causes them to experience air resistance, but the farther the convergence point is from the spinneret, the greater the air resistance experienced by the yarn groups, and the higher the spinning tension. It is something to be used.

Furthermore, in the present invention, the yarn groups A and B may be subjected to fluid entanglement treatment before reaching the take-up roller or between the take-up roller and the wind-up roller.

Further, examples of heating means for heat treatment performed after yarn groups A and II are taken off by a take-up row include roller heat treatment, heating tubes, heating heater plates, and the like. The heat treatment time is also not particularly limited, and varies depending on differences in heating temperature, winding speed, single yarn fineness, etc., but for practical purposes, o, oo
s to 0.10 seconds is preferred.

Note that when the stretching operation is performed in the present invention, crystallization proceeds simultaneously with orientation, and the difference in heat shrinkage rate becomes smaller.

Forcibly stretching between rollers is not preferred.

Next, one embodiment of the present invention will be explained with reference to the drawings.

In FIG. 1, the focusing position of the yarn group A discharged from the spinneret 1 and the yarn group B discharged from the spinneret 2 by the oil supply guide 3.4 is changed, and the spinning tension is 0.6 g/ d
Hereinafter, yarn group B is adjusted to have a spinning tension of 0.7 g/d or more and a difference in spinning tension between the two to be 0.2 g/d or more. After the yarn groups A and B running at the above spinning tension are interlaced by an interlacer 5, they are taken up by a take-up roller 6 and then heated by a heating roller 7 at a temperature of 70 to 150°C above the melting point (Tm) of polyester.
After being heat-treated at a low temperature, it is wound up onto a paper tube 8 at a winding speed of 4,000 m/min or more.

The present invention is not limited to the embodiment shown in FIG. 1; for example, yarn groups Δ and B discharged from the same spinneret 1 as shown in FIG. 2 may be used.

Further, the discharge hole of the spinneret 1.2 is not limited to a circular cross section, and various irregular cross-sectional shapes may be used.

Two measuring methods in the present invention will be explained below.

The spinning tension of yarn group A, [1 is determined by measuring the tension 5 cm below the point where the spun yarns are focused using a tension measuring device type R manufactured by Rososeal Co., Ltd.
-1092. What is the heat shrinkage rate?

The sample length (Lo) at an initial load of 1/30 g/d and the measured length Ll after removing the load, processing it in boiling water for 30 minutes, air drying, and applying a load of 1/30 g/d again.
) was calculated using the following formula.

Heat shrinkage rate: S = (Lo - L+) / (Lo X 1
00 (%) Furthermore, a polarizing microscope equipped with a Berek compensator was used to measure birefringence, and tricresyl phosphate was used as the immersion liquid. The strength and elongation of the yarn was determined using Autograph DSS-500 manufactured by Kinsei Seisakusho, with a sample length of 30 cm.
Measurement was performed at a tensile speed of 30 cm/min. however.

Elongation refers to cutting elongation.

(Examples) The present invention will be explained in more detail below with reference to Examples. In addition, the relative viscosity ηr of the polymer in the examples was determined at a concentration of 0.5 in a 1/1 mixed solvent of phenol/tetrachloroethane at 25°C.
Measured in g/100cc.

Example 1 Using an extruder-type melt spinning machine and following the steps shown in FIG. 1, the relative viscosity ηr was 1.38. Polyethylene terephthalate chips with a melting point of 275° C. were spun as yarn group B, B from a spinneret 1.2 with a hole diameter of 0.2 m+sφ and a number of holes of 36 at a melting temperature of 290° C.

Next, thread group A and thread group B are each oiled by oil guide 3.4.
The fibers were bundled with an interlacer 5, then taken up with a take-off roller, further wrapped around a heating roller 6 times for heat treatment, and then wound up into a paper tube 8 with a winding machine. In addition, yarn group A,
The spring water shrinkage rate of B was measured on a sample in which each yarn was experimentally wound into a separate pancage without being combined. Further, yarn groups A and B were both set to 75 d/36 f, and the speeds of the take-up roller, heating roller, and winding were the same. The results are summarized in Table 1.

As is clear from Table 1, one example of the present invention, 3.6.
In case 7, the difference in heat shrinkage was large, and it was possible to produce a mixed shrinkage yarn with good strength and elongation for ease of operation.On the other hand, in case 4, where the spinning tension was extremely low, yarn group A was Paid 8
It focused at 0cm.

Occasionally, adhesion occurred between yarns, causing problems in operability.

(Effects of the Invention) According to the present invention, different shrinkage mixed fibers can be obtained through a simple process of varying the spinning tensions of the melt-spun yarn groups A and B to give a difference in molecular orientation, and then heat-treating and crystallizing the melt-spun yarn groups A and B. Yarn can be manufactured. In addition, since the same heat treatment is applied after yarn groups A and B are combined, the adjustment range of heat shrinkage is wide. Excellent.

Furthermore, since there is no need for a stretching process, special rollers are installed,
Different shrinkage mixed fiber yarns can be efficiently produced without changing the roller diameter.

[Brief explanation of drawings]

FIG. 1 is a schematic process diagram showing one embodiment of the present invention. FIG. 2 is a schematic process diagram showing another embodiment. 1.2: Spinneret + 3 + 4: Refueling guide. 6: Take-up roller, 7: Heating roller.

Claims (1)

[Claims] (1) Polyester fibers are melt-spun and divided into two yarn groups A and B, and the spinning tension of yarn group A is 0.6 g/d or less;
Yarn group B is bundled separately so that the spinning tension is 0.7 g/d or more and the difference in spinning tension between both yarn groups is 0.2 g/d or more, and then yarn group A and yarn group After doubling yarn B and taking it off with the same take-up roller, the melting point of polyester is 70~
Heat treated at a lower temperature of 150°C, followed by 4,000mm
1. A method for producing a differentially shrinkable mixed fiber yarn, characterized by winding the yarn at a speed of /min or more.