JP2023051749A - Manufacturing method of composite fiber - Google Patents

Abstract

To provide a manufacturing method capable of improving production efficiency and stably obtaining a composite fiber with excellent quality for an extended period of time, in a direct spinning drawing method.SOLUTION: The manufacturing method of the composite fiber, formed by bonding a polyester and a polyamide in a longer direction, carries out melt-spinning using the polyester with a melt index at 290°C of 1.50 g/10 min or more and less than 2.50 g/10 min, and the polyamide with the melt index at 290°C of 1.50 g/10 min or more and less than 2.50 g/10 min.SELECTED DRAWING: None

Description

The present invention relates to a method for producing bicomponent fibers of polyester and polyamide.

Conventionally, as a method for producing composite fibers containing polyester and polyamide as components, there is a method (conveyor method) in which undrawn yarn collected in the spinning process is drawn in the draw-twisting process in a two-step process (conveyor method). When manufacturing, there is a problem of poor production efficiency.

On the other hand, as a method for increasing production efficiency, a direct spinning drawing method (hereinafter sometimes referred to as SPD method) in which drawing is performed without winding once after spinning and a high speed spinning method are known. In the case of components with different properties, the production by the SPD method has poor spinning operability, and the production technology has not been established. There are many proposals regarding methods for producing composite fibers made of polyester and polyamide. A method has been proposed in which the spinning operation is stabilized for a long period of time and a conjugate fiber of good quality is obtained by increasing the viscosity.

JP 2009-270207 A JP-A-4-11020 JP 2006-322131 A

However, when it was produced by the SPD method with reference to the proposals of Patent Documents 1 to 3, it was not possible to stably obtain a conjugate fiber of good quality due to frequent yarn breakage when actually spun for a long time.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-described problems and to provide a method for producing conjugate fibers of good quality stably for a long period of time while increasing the production efficiency even in the SPD method.

The present inventors have found that by setting the melt index of polyester and polyamide within a specific range, it is possible to stably obtain composite fibers of good quality not only by the production method in the two-step process but also by the SPD method. .
That is, the present invention solves the above problems, and the gist of the configuration is as follows.
(1) A method for producing a composite fiber obtained by joining polyester and polyamide in the longitudinal direction, comprising a polyester component having a melt index at 290 ° C. of 1.50 g / 10 min or more and less than 2.50 g / 10 min, and A method for producing a composite fiber, comprising melt spinning a polyamide having a melt index of 1.50 g/10 min or more and less than 2.50 g/10 min.
(2) The method for producing a conjugate fiber according to (1), characterized in that the production is carried out by a direct spinning-drawing method.
(3) The method for producing a composite fiber according to (1) or (2), wherein the fineness is 30 dtex or more and 120 dtex or less.
(4) The method for producing a composite fiber according to any one of (1) to (3), wherein the number of filaments is 15 to 60.
(5) The method for producing a composite fiber according to any one of (1) to (4) above, wherein polyester and polyamide are alternately arranged in the cross-sectional shape of the fiber.
(6) The conjugate fiber according to any one of (1) to (5), wherein the polyamide having a radial cross-sectional shape of the fiber and the polyester having a shape complementary to the radial shape are arranged alternately. manufacturing method.
(7) The production method according to any one of (1) to (6), wherein the conjugate fiber is a splittable conjugate fiber.

ADVANTAGE OF THE INVENTION According to this invention, the conjugate fiber with few thread breakage and good quality can be stably obtained for a long period of time by the SPD method. In addition, the improvement in yield associated with the improvement in yarn breakage can provide a conjugate fiber with reduced production costs.

It is an example which shows the cross-sectional view of the composite fiber of this invention.

The present invention will be described in detail below. SUMMARY OF THE INVENTION The present invention is a method of making bicomponent fibers comprising polyester and polyamide.

The method for producing the conjugate fiber of the present invention may be a two-step process in which the undrawn yarn is wound up and then drawn. and cost efficiency can be improved.

As the polyester, for example, polyethylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and copolymerized polyesters containing these as components are known, and polyethylene terephthalate is generally used and preferred.

On the other hand, as the polyamide, for example, nylon 6, nylon 66, nylon 4, nylon 7, nylon 11, nylon 12, poly-meta-xylene adipamide and the like are known, but nylon 6 is versatile and preferable.

The melt index at 290° C. of polyester and polyamide, which is the most important point of the present invention, must be 1.50 g/10 min or more and less than 2.50 g/10 min. Within this range, it is possible to stably obtain conjugate fibers with less yarn breakage and good quality even by the SPD method.

In particular, when the melt index of the polyamide is less than 1.50 g/10 min, there are many yarn breakages during the spinning stage, making it difficult to produce by the SPD method.

Polyesters and polyamides are pre-dried prior to melt spinning.
In the case of polyethylene terephthalate, the moisture content after drying is preferably 5 ppm to 25 ppm, more preferably 10 ppm to 20 ppm. On the other hand, in the case of nylon 6, the moisture content after drying is preferably 70 ppm or less, more preferably 50 ppm or less. Within this range, it is possible to stably obtain conjugate fibers of good quality with little yarn breakage during spinning.

The above dry polyester and polyamide are prepared, melted, and extruded using a composite spinneret. The spinning temperature at this time is preferably 295 to 300°C. After being discharged, it is cooled, then an oil solution is applied, and the film is stretched. After application of the oil agent, for example, it is taken up by a pretension roller (PTR) and a first godet roller (GR1), then stretched between GR1 and a second godet roller (GR2), and wound onto a bobbin to obtain a conjugate fiber. be able to.
Here, the volume ratio of polyester to polyamide is preferably 2:1 to 3:1.

The single filament fineness of the composite fiber in the present invention is preferably 0.5 to 10 dtex, more preferably 1 to 5 dtex. Within this range, it is possible to stably obtain conjugate fibers of good quality with little yarn breakage during spinning.

The fiber cross-sectional shape of the conjugate fiber in the present invention is preferably such that polyester and polyamide are alternately arranged, and moreover, polyamide having a radial shape and polyester having a shape complementary to the radial shape are alternately arranged. preferably. An example is shown in FIG.
In FIG. 1(a), the polyester (hatched area) having a shape that complements the radial polyamide is divided into eight parts, and FIG. 1(b) shows the polyester (hatched area) having a shape that complements the radial polyamide. It is divided into 4 parts.

EXAMPLES The present invention will be specifically described below with reference to Examples. It should be noted that the present invention is not limited to the examples described below. Incidentally, the characteristic values in the following examples were measured by the following methods.

Physical properties were measured as follows.
(1) A sample was taken from the chip after the polyester melt index drying treatment, and dried at 180° C. for 2 hours in a vacuum dryer to obtain a sample. In the measurement, a melt indexer device (model F-F01) manufactured by Toyo Seiki Co., Ltd. was used. The polymer was extruded through an orifice of 0.000 mm, the mass of the extruded polymer was measured for 60 seconds, and the melt index was calculated according to the following formula.
Melt index (g/10min) = [(n1 + n2 + n3)/3] x 10
(n1 to n3 = sample mass) (2) The same method as for polyester, except that a sample is taken from the chip after the polyamide melt index drying treatment and dried at 150 ° C. for 2 hours in a vacuum dryer to obtain a sample. to calculate the melt index.
(3) Fineness measurement method According to JIS-L-1013, a small skein of yarn length of 100m was made using a measuring machine with a frame circumference of 1.25m, and the apparent fineness was calculated by weighing the mass.
(4) Strength and elongation measurement method According to JIS-L-1013, using an AGS 1KNG Autograph (registered trademark) tensile tester manufactured by Shimadzu Corporation, under the conditions of a sample thread length of 200 mm and a tensile speed of 200 m / min. The strength (cN/dtex) and elongation (%) when the sample was stretched and broken were determined.
(5) Spinnability Composite fibers are spun by the SPD method and the conveyor method, and the number of yarn breakages within 24 hours is 3 times or less, and the operability is good, and the number of yarn breakages within 24 hours is 4 times. Poor operability was evaluated as x.

[Example 1]
Polyethylene terephthalate (PET) having a melt index at 290°C of 1.62 g/10 min and a moisture content of 15 ppm after drying as the polyester is melted at 285°C, and nylon 6 having a melt index at 290°C of 2.13 g/10 min and a moisture content of 37 ppm after drying as the polyamide. is melted at 260 ° C., and the volume ratio of PET / nylon 6 is 2 so that nylon 6 having a radial fiber cross section and polyethylene terephthalate having a shape that complements the radial shape are divided into 8 parts (a) in FIG. / 1 and 25 holes, discharge at a spinning temperature of 295 ° C., apply oil after cooling, pretension roller (PTR) with a peripheral speed of 1140 m / min, peripheral speed of 1160 m / min (78 ° C.) six times on a first godet roller (GR1) and taken off, then six times on a second godet roller (GR2) with a peripheral speed of 3800 m/min (118° C.) and stretched between GR1 and GR2. A composite fiber of 84 dtex/25 f was obtained by the SPD method.

[Example 2]
A composite fiber of 56 dtex/25 f was obtained by the same manufacturing method as in Example 1 except that the fineness was changed.

[Example 3]
56 dtex by the same manufacturing method as in Example 1 except that the fineness and cross-sectional shape of the fiber are changed so that the radial nylon 6 and the polyethylene terephthalate having a shape that complements the radial shape are divided into four parts as shown in FIG. A bicomponent fiber of /28f was obtained.

[Comparative Example 1]
Polyethylene terephthalate (PET) with a melt index at 290°C of 1.62 g/10 min and a moisture content of 13 ppm after drying as the polyester is melted at 285°C, and nylon 6 with a melt index at 290°C of 0.67 g/10 min and a moisture content of 32 ppm after drying as the polyamide. is melted at 270 ° C., and the volume ratio of PET / nylon 6 is 2 so that nylon 6 having a radial fiber cross section and polyethylene terephthalate having a shape that complements the radial shape are divided into 8 parts (a) in FIG. Using a composite spinneret with / 1 and 25 holes, discharging at a spinning temperature of 295 ° C., applying an oil solution after cooling, peripheral speed peripheral speed 1240 m / min (72 ° C.) on the first godet roller (GR1) The composite fiber of 56 dtex/25 f is obtained by the SPD method, which is wound 6 times and taken off, then wound 6 times around a second godet roller (GR2) with a peripheral speed of 3800 m/min (130°C), and drawn between GR1 and GR2. Obtained.

[Comparative Example 2]
56 dtex/28 f by the SPD method in the same manner as in Comparative Example 1 except that nylon 6 having a radial fiber cross-sectional shape and polyethylene terephthalate having a shape that complements the radial shape are divided into four parts as shown in FIG. of composite fibers were obtained.

[Reference Example 1]
Using the same raw material as in Comparative Example 1, melting at 270 ° C., nylon 6 having a radial fiber cross section and polyethylene terephthalate having a shape that complements the radial shape are divided into eight parts, so that FIG. Using a composite spinneret with a PET/nylon 6 volume ratio of 2/1 and 25 holes, spinning was discharged at a spinning temperature of 295 ° C., and after cooling, an oil was applied, and a spinning speed of 1060 m / min was performed by a conveyor method. The undrawn yarn was once wound up and drawn in a drawing step to obtain a 56 dtex/25 f conjugate fiber.

Table 1 shows the production method of the composite fibers obtained in Examples 1 to 3, Comparative Examples 1 and 2, and Reference Example 1, the melt index of polyester and polyamide, the fineness, the number of filaments, the strength, the elongation, and the evaluation of the spinning runnability. shown in

Claims (7)

A method for producing a composite fiber obtained by joining polyester and polyamide in the longitudinal direction, comprising:
Melt spinning using a polyester having a melt index at 290° C. of 1.50 g/10 min or more and less than 2.50 g/10 min and a polyamide having a melt index at 290° C. of 1.50 g/10 min or more and less than 2.50 g/10 min A method for producing a composite fiber, characterized by: 2. The method for producing a conjugate fiber according to claim 1, wherein the production is carried out by a direct spinning drawing method. 3. The method for producing a composite fiber according to claim 1, wherein the fineness is 30 dtex or more and 120 dtex or less. The method for producing a composite fiber according to any one of claims 1 to 3, wherein the number of filaments is 15 to 60. 5. The method for producing a conjugate fiber according to any one of claims 1 to 4, wherein the cross-sectional shape of the fiber is such that polyester and polyamide are alternately arranged. The method for producing a conjugate fiber according to any one of claims 1 to 5, wherein the polyamide having a radial cross-sectional shape of the fiber and the polyester having a shape complementary to the radial shape are alternately arranged. The production method according to any one of claims 1 to 6, wherein the conjugate fiber is a splittable conjugate fiber.

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