JPS641570B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for false twisting a yarn formed by aligning two or more types of nylon 6 fibers having substantially the same single yarn fineness and different cross-sectional shapes. [Prior Art] When a round cross-section fiber is mixed with a deformed cross-section fiber to make a false-twisted yarn, the surface gloss and texture of the knitted fabric can be improved without impairing the good properties such as stiffness and tension. Therefore, the false-twisted yarn, which is a mixture of two or more types of fibers with different cross-sectional shapes, is useful for knitted fabrics. However, since the irregular cross-section mixed fiber yarn to be subjected to false twisting has conventionally been composed of drawn fibers, the obtained false twisted yarn has many problems. For example, there were problems in that the crimp properties were poor, the dyeing properties were poor, and the crimp properties varied widely between fibers. Furthermore, when false-twisting nylon thread, it is necessary to equalize the elongation between the fibers, and if this elongation balance is disrupted, the twisting during the false-twisting process becomes unstable, resulting in problems not only in workability but also in processing. The yarn properties are also significantly reduced. Therefore, if two or more types of fibers with different cross-sectional shapes are drawn from the same die, drawn at the same time, and false-twisted at the same time, the processing becomes difficult because the fibers will not be properly woven together. Therefore, in the conventional method, after spinning and drawing the fibers individually with the same elongation, it was necessary to align the fibers and supply them to the false twisting process. moreover,
Even if such a method is adopted, it has not been possible to completely improve the "ability" with conventional methods. [Problems to be Solved by the Invention] An object of the present invention is to false-twist a mixed fiber yarn with an irregular cross section consisting of two or more types of fibers having substantially the same single yarn fineness but different cross-sectional shapes, to achieve luster, shine, The texture is good,
It can be made into a knitted fabric with a waist and tension, and
The purpose of the present invention is to obtain a false-twisted yarn with excellent crimp fastness and dyeing properties, and to improve processing properties such as "softness" during processing. [Means for Solving the Problems] In order to achieve the above object, the present invention temporarily creates a yarn made by aligning two or more types of nylon 6 fibers having substantially the same single filament fineness and different cross-sectional shapes. In the twisting method, the nylon 6 fibers are taken at a first Godet roller speed of 3000 m/min or more,
The elongation (S) is 50-80% and the density (ρ) is obtained by winding at 3500m/min or more without heat treatment.
1.133g/ ^cm3 or less and 15% elongation stress (F)
Using nylon 6 fibers with a weight of 1.0 to 2.0 g/d, the overfeed rate of the false twisting process was -10
~-30%. The false-twisted yarn to which the method of the present invention is applied is
The single yarn fineness is substantially the same, and the cross-sectional shape is
It is a so-called mixed cross-section nylon 6 yarn made by aligning two or more types of nylon 6 fibers with different cross sections, such as round cross sections and deformed cross sections. Here, the single yarn fineness or cross-sectional shape of two or more types of nylon 6 fibers refers to the average value of the single yarn fineness or the average cross-sectional shape of each type. The degree of difference between each type of cross-sectional shape can be determined according to the desired requirements such as gloss, texture, elastic stress (waistiness, tension), etc., as with conventional mixed cross-sectional yarns.
If the degree of difference is too small, the above characteristics cannot be substantially improved sufficiently. In order to improve these characteristics, generally the difference in deformation between each type (the maximum difference if three or more types are used) should be approximately 20% or more, or the cross-sectional shape between each type should be a trilobal shape. It is sufficient to make them clearly different, such as the and hexalobal shapes. A fiber with a deformed cross section (deformed cross section yarn) has a degree of deformation (=average of the values of circumscribed circle radius/inscribed circle radius of deformed cross section yarn for all filaments) of 1.4.
It is preferable that the value is between 3.0 and 3.0; otherwise, the properties of the modified cross-section yarn (glossy, texture, etc. of the product fabric) cannot be fully exhibited. Furthermore, as the yarn with a deformed cross section, a trefoil deformed yarn is particularly preferable. The nylon 6 fibers, which are mixed with irregular cross-sections and are used as raw yarn for false twisting, are taken up by a first Godet roller installed under the spinneret that rotates at high speed, and then passed through a second Godet roller. hand,
It is obtained by a so-called high-speed direct spinning method in which it is wound without heat treatment, and some stretching may be applied between the first Godet roller and the second Godet roller. In the above method, the speed of the first godet roller and the winding speed need to be 3000 m/min or more and 3500 m/min or more, respectively. [Function] If the speed of the first godet roller is less than 3000 m/min or the winding speed is less than 3500 m/min, the crimp fastness of the processed yarn obtained will be low and the resulting product fabric will lack stiffness. However, the texture becomes poor. Moreover, dyeing fastness and dyeing uniformity are significantly reduced, making it impossible to obtain dyeing properties at a practical level.
Furthermore, it tends to generate fuzz during false twisting and lacks processing stability. The speed range of the present invention not only eliminates the above-mentioned drawbacks, but also makes it easier to match the elongation between fibers and improves the "melting". The supplied yarn obtained by this method further has elongation (S), density (ρ) and 15% elongation stress (F) of 50%≦S≦80% ρ≦1.133g/cm ³ 1.0g/d It is necessary that ≦F≦2.0 g/d. In addition, when the birefringence (△n) of the fiber can be measured, such as when the fiber cross section is round, the birefringence (△n) is 32 × 10 ^-3 ~ 41 ×
10 ^-3 is desirable. In addition, also in the case of a modified cross-section yarn, it is desirable to have a fiber orientation structure equivalent to the fiber structure represented by the above-mentioned birefringence range. If the elongation of the supplied raw yarn is less than 50%, fuzz will occur during processing.
Yarn breakage is likely to occur, and the crimp properties of the resulting processed yarn are reduced. On the other hand, if it exceeds 80%, untwisting and fluffing tend to occur. Furthermore, if the density exceeds 1.133 g/cm ³ , dyeing spots are likely to occur in the processed yarn obtained, and fuzz and thread breakage are likely to occur during processing. In addition, the 15% elongation stress
If it is less than 1.0, the dyeing fastness of the resulting processed yarn will decrease, while if it exceeds 2.0, the crimp fastness will decrease,
In addition, "Kanare" becomes defective. When false-twisting the supplied raw yarn,
It is necessary to process under conditions of an overfeed rate of -10 to -30%. If the overfeed rate is greater than -10%, the dyeing properties will be poor, and if the overfeed rate is less than -30%, the crimp properties will be poor. The false twisting processing conditions other than the overfeed rate, such as the number of false twists, the false twisting temperature, the false twisting device, etc.
It may be the same as the conventional conditions, and there is no particular limitation. It is preferable that the above-mentioned supplied raw yarn is obtained by spinning from a spinneret with different shaped spinnerets in the same spinneret and simultaneously making it into a blended yarn. Good too. Note that the birefringence (Δn), elongation (S), density (ρ), and 15% elongation stress (F) used in the present invention are values measured by the following method. Birefringence (△n): This was determined using a polarizing microscope manufactured by Nippon Kogaku Co., Ltd. equipped with a Bereck compensator and using a white light source. Elongation (S): The sample was left in a test room at 20°C and 65% relative humidity for 24 hours, and the sample was taken directly from the package using a constant-speed extension type tensile tester (S) under an initial load of 1/30 g/d. (Using “Instron”) and hold it at a distance of 20 cm.
This was determined by clamping the yarn at a speed of 20 cm/min, and reading the elongation rate at maximum strength. Density (ρ): A density gradient solution was prepared by continuously changing the mixing ratio of carbon tetrachloride and toluene, and the density was measured using the density gradient tube method (using a direct-reading density measuring device manufactured by Shibayama Kagaku Kikai Seisakusho). 15% elongation stress (F): This is determined by reading the stress at 15% elongation in the elongation measurement method described above. [Example] Example 1 Two types of nylon 6 fibers with the same single yarn fineness and different degrees of deformation were spun, and the first Godet roller speed was 3700.
By high-speed spinning at a winding speed of 3,900 m/min and a winding speed of 3,900 m/min, a drawn yarn consisting of two types of nylon 6 fibers (described below) was obtained. This nylon 6 fiber has an elongation of 65
%, density 1.128, and 15% elongation stress 1.5 g/d.

[Table] The obtained drawn yarn was false-twisted at 170° C. with a twist of 3200 t/m under -14% overfeed, and the obtained processed yarn was made into a knitted fabric and finished with dyeing. The processing properties were good, and no poor handling was observed as in the conventional method of false twisting as a drawn yarn after spinning, winding, and stretching. Moreover, the crimp fastness of the obtained processed yarn was significantly improved compared to the processed yarn processed by the conventional method, and was sufficient for practical use. The knitted fabric obtained from this processed yarn has a smooth surface, a dry touch, no dyeing spots, and
The waist and stretch properties of the knitted fabric were also satisfactory. Comparative Example 1 After separately spinning, winding, and stretching two types of nylon 6 fibers with the same single yarn fineness and different degrees of deformation,
It was made into an aligned thread. This nylon 6 fiber has elongation
40%, density 1.136, and 15% elongation stress 3.9 g/d.

〔Effect of the invention〕

According to the method of the present invention, the twisted state during false twisting is extremely stable, and a processed yarn can be obtained that has a degree of good flexibility that cannot be obtained with conventional methods. A knitted fabric that has fastness and dyeing properties, has good luster and texture, and has elasticity and tension can be obtained. In addition, it can also be used as a drawn yarn with a mixed cross-section of modified fibers by spinning the supplied raw yarn using a single spinneret.
In the method of the present invention, a blended yarn with a good deformed cross section and a smaller orientation difference between fibers than in the conventional method can be used as the raw yarn for false twisting, so handling and mellowness during the false twisting process can be improved. Therefore, according to the present invention, it is practically possible to false-twist the deformed cross-section mixed fiber yarn obtained by spinning and blending from a single spinneret.

Claims (1)

[Claims] 1. In a method of false-twisting a yarn formed by aligning two or more types of nylon 6 fibers having substantially the same single yarn fineness and different cross-sectional shapes, the first godet roller speed is 3000 m/min or more as the nylon 6 fibers. The elongation (S) is 50 to 80%, obtained by winding at 3500 m/min or more without heat treatment.
Nylon 6 fibers with a density (ρ) of 1.133 g/cm ³ or less and a 15% elongation stress (F) of 1.0 to 2.0 g/d are used, and the overfeed rate of the false twisting process is -10 to A method for false twisting nylon 6 yarns with mixed cross-sections of irregular cross-section, characterized by -30%.