JP2010037675A - Spinneret for modified cross-section fiber yarn - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spinneret capable of making a melt spinning of a modified cross-section multifilament yarn with a nearly equilateral-triangular fiber cross section excellent in silk-like glossy feeling, and also enabling its own nozzle shape to be made easier and more inexpensively than ever. <P>SOLUTION: The spinneret for modified cross-section fiber yarn has the following design: Semicircles each with a radius of curvature (R) are processed respectively at three apexes (A, B and C) forming the respective tips of slit holes branched in three-way fashion at equal angles. The ratio (R/L) is (1:8) to (1:12) (wherein (L) is the length of a line segment connecting each of the apexes (A, B and C) and the center (O)). When the midpoints (M) of the respective sides of an equilateral triangle formed by connecting the apexes one another with a straight line each and points (N) where the respective line segments MO connecting the midpoints (M) and the center (O) and the profile line of the discharge hole intersect are imagined, the ratio (l<SB>1</SB>/l<SB>2</SB>) is (2.8:2) to (3.2:2) (wherein l<SP>1</SP>is the line segment OM's length, and l<SB>2</SB>is the line segment ON's length). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spinneret for obtaining a modified cross-section fiber from a melt or solution of a thermoplastic synthetic polymer, and in particular, spinning for obtaining a modified cross-section yarn having a substantially equilateral triangular shape in the cross section of the fiber. Regarding the base.

  Generally, a Y-shaped slit hole is known as a spinneret for obtaining a modified cross-section yarn from a thermoplastic synthetic polymer (hereinafter simply referred to as “polymer”) such as polyester, polyamide, and polyolefin. ing. Among the modified cross-section yarns obtained from the spinneret with the Y-shaped polymer discharge holes, the cross-section of the fibers is an equilateral triangle. Can give a feeling and texture. Furthermore, fibers having a regular triangular cross section also have a characteristic that they are suitable for densely filling these fiber groups without gaps.

  However, since the polymer immediately after being discharged from the spinneret swells once due to the Belas effect, it is difficult to obtain a fiber having a substantially equilateral triangular cross section after spinning. However, as illustrated in FIG. Has proposed a spinneret for obtaining such a fiber cross section. Here, the Y-shaped polymer discharge hole provided in the spinneret proposed in Patent Document 1 will be briefly described. The discharge hole is equiangular at 120 ° with the slit width gradually reduced from the center O. And three slit holes L, M, and N extending radially.

Further, each slit holes is _{L l 1} away point from the center _{O 1, M 1, N 1} l 2 away point from the center O from _{L 2,} M 2, _N r next slit width is constant up to ₂ At each end of the slit hole portion, a semicircle having a diameter r and a center at the points L ₂ , M ₂ , and N ₂ is provided. A concave arc sandwiched between adjacent slit holes constitutes a part of the circumference of a circle with a radius R centered on O ₁ , O _2, and O ₃ , and includes a straight line O ₁ M ₁ O ₂ , a straight line O ₂ N ₁ O ₃ and straight line O ₃ L ₁ O ₂ are equal in length and form an equilateral triangle O ₁ O ₂ O ₃ .

In this case, in order to obtain a substantially equilateral triangular fiber cross section, in Patent Document 1, the ratios of R and r and r and l (where l = l ₂ −l ₁ ) are extremely important. r is required to be in the range of 1.5 to 5.0 and r / l to be in the range of 0.35 to 7. However, as is apparent from FIG. 3 described above, when a large number of discharge hole groups (usually, 30 or more discharge hole groups) having such a complicated shape are formed in one spinneret. , Its production cost increases.

Further, when used for a long period of time, the edge portion is worn by the polymer flowing out from the discharge hole, and the shape thereof is changed. As a result, the shape of the modified cross-section fiber, which initially had a substantially equilateral triangular cross-sectional shape, has a rounded circular cross-section, and has a high-performance characteristic of silky luster due to the prism effect. It becomes impossible to obtain a modified cross-section yarn having
Japanese Patent Laid-Open No. 62-9717

  In view of the problems of the prior art described above, the object of the present invention is to melt-spin a modified multi-filament yarn having a substantially equilateral triangular fiber cross section excellent in silk-like glossiness, and its An object of the present invention is to provide a spinneret for deformed cross-section yarns that can be produced more easily and cheaply than conventional ones.

The object of the present invention is “a spinneret for spinning a deformed multifilament yarn having a substantially transverse triangular cross section by discharging a molten thermoplastic polymer from a plurality of discharge holes,
The discharge hole is formed of three slit holes having the same shape extending from the center (O) and diverging in three directions in a Y-shape by gradually reducing the slit width radially from the center (O). ,
Further, semi-circles each having a radius of curvature (R) at each of the three apexes (A, B, and C) forming the tips of the slit holes branched in three directions are respectively processed.
A dimensional ratio (R / L) between the radius of curvature (R) and the length (L) of the line segment connecting each vertex (A, B, and C) from the center (O) is 1/8 to 1 / In the range of 12,
A midpoint (M) of each side of an equilateral triangle formed by connecting the vertices (A, B and C) with straight lines, and a line segment MO connecting the midpoint (M) and the center (O). When a point (N) where the outer shape lines of the discharge holes intersect is assumed, a dimensional ratio (l ₁ / l) between the length of the line segment OM (l ₁ ) and the length of the line segment ON (l ₂ ) ₂ ) is in the range of 2.8 / 2 to 3.2 / 2 ”and can be achieved by a spinneret for irregularly shaped cross-section fibers”.

  According to the present invention, it is possible to obtain a deformed cross-section multifilament yarn having a substantially equilateral triangular shape whose fiber cross section has never been obtained, and since it has a substantially equilateral triangular cross section, the prism effect is strongly expressed and is excellent. Shows gloss. In addition, since the obtained multifilament yarn having an irregular cross section has a cross section close to an equilateral triangle, when these layers are arranged and laminated in layers, the multifilament yarn can be closely packed without a gap.

In addition, the discharge holes drilled in the spinneret according to the present invention have the same shape and are arranged in three equal positions (the included angles are 120 °) and the radii of curvature at the tips of the three slit holes branched in three directions. Forms a semicircle of R, and the dimensional ratio (R / L) is within a range of 1/8 to 1/12, and the dimensional ratio (l ₁ / l ₂ ) is 2.8 / 2. What is necessary is just to drill so that it may fit in the range of -3.2 / 2. Therefore, complicated and elaborate processing as in the prior art is not required, and therefore, the manufacturing is easy and the manufacturing cost is low.

The spinneret according to the present invention will be described in detail below with reference to the drawings.
FIG. 1 is a plan view (viewed from the polymer discharge surface side) for explaining the shape of a discharge hole formed in a spinneret used when spinning a modified cross-section yarn.

  FIG. 1 shows a polymer discharge surface of a spinneret that is composed of three slit holes that branch radially in three directions while forming a Y-shape and that have exactly the same hole shape. FIG. At this time, the slit holes branched in a Y-shape are radially formed while gradually reducing the slit width in a state in which an angle of 120 ° is formed in three directions with respect to the center line of each slit hole from the center of the branch. The branch extends in three directions.

  Further, in FIG. 1, symbols A, B, and C respectively indicate the vertices of an equilateral triangle described by dotted lines (also vertices of three slit holes), and symbol O represents the center of the equilateral triangle (that is, 3 is also the center of the branch where the three slit holes branch). Furthermore, the symbol R described in the vicinity of the symbol A indicates the radius of curvature when the curvature processing is performed on the apex that is the tip of the slit hole. The radius of curvature R is usually set to the same value for each vertex A, B, and C unless there is a special reason.

  Next, the code | symbol M and the code | symbol N are demonstrated. First, the symbol M is the midpoint of each side AB, BC and CA (in the figure, the case of the side BC) of the equilateral triangle ABC indicated by the dotted line, and the symbol N is the line segment MO and the discharge hole ( It is a point that intersects with the outline of the slit hole branched in three directions. At this time, it is important that the shape of the discharge hole formed in the spinneret of the present invention has the characteristics described in the following (1) and (2).

  (1) At each vertex A, B, and C, a dimensional ratio (R) between the radius of curvature (R) and the length (L) of each line segment connecting each vertex A, B, and C from the center O of the regular triangle. / L) is in the range of 1/8 to 1/12. This is because, when R / L is smaller than 1/12, a force to make a circular shape is exerted greatly due to the influence of the surface tension of the polymer to be spun even if an irregular yarn having an equilateral triangular cross section is obtained. This is because the shape is close to a rice ball shape and the desired cross-sectional shape cannot be obtained. Further, when R / L is larger than 1/8, the polymer discharged from the discharge hole swells due to the balus effect, and the bulge is increased particularly at each of the vertices A, B, and C, resulting in a triangle having a rounded vertex. It does not become a triangle with a sharp vertex. Therefore, it is considered that the above ratio is an optimum value.

(2) Dimensional ratio of “length of line segment connecting middle point M and middle point O (l ₁ )” and “length of line segment connecting point N and middle point O (l ₂ )” Let (l ₁ / l ₂ ) be approximately 3/2 (2.8 / 2 to 3.2 / 2). This is because, if the ratio is out of the above-mentioned ratio range, the modified cross-sectional yarn is not preferable because a Y-shaped yarn having a constriction or a modified cross-sectional yarn close to a circular shape is formed. Therefore, the above ratio is an optimum value.

Hereinafter, using the spinneret according to the present invention, in a Y-shaped discharge hole having a substantially equilateral triangular fiber cross-sectional shape, each vertex A, B from the center O of the equilateral triangle indicated by the dotted line in FIG. In addition, the length (L) of the line segment connecting C and C is 0.35 mm, and the curvature radius R is 0.030 mm in the curvature processing applied to each of the vertices A, B, and C in a semicircular shape. Further, dimensional ratio of “the length of the line segment connecting the middle point M and the middle point O (l ₁ )” and “the length of the line segment connecting the point N and the middle point O (l ₂ )”. (L ₁ / l ₂ ) is set to 3/2, and the constricted portion (concave portion) formed between adjacent vertices of the Y-shaped discharge hole has a radius of curvature of 0.5 mm at each point N In this way, it was connected to the curvature machining part (semicircle machining part) of each vertex A, B and C with a smooth curve.

  Then, 30 polymer discharge holes formed as described above were formed in one spinneret. Using this spinneret, polyethylene naphthalate was spun at 200 g / min (6.67 g / min per hole) at a winding speed of 1000 m / min. In this case, when the fiber cross section of each filament obtained was photographed with an optical microscope and photographed, a good substantially equilateral triangular shaped cross-section yarn as shown in FIG. 2 could be obtained.

It is explanatory drawing of the discharge hole shape drilled in the spinneret based on this invention for spinning a triangular cross-section yarn. It is the photograph which image | photographed the fiber cross section of the triangular cross-section yarn obtained using the spinneret which concerns on this invention with the optical microscope. It is explanatory drawing (plan view) of the discharge hole shape pierced in the conventional spinneret for spinning a triangle section yarn.

Explanation of symbols

A, B, C Each vertex of the equilateral triangle L Length of each segment connecting the center of the equilateral triangle and each vertex M Midpoint of each side of the equilateral triangle N A straight line extending the segment AO is the outline of the discharge hole Intersection point R Curvature radius of curvature applied to each vertex O Center of equilateral triangle ABC

Claims (2)

A spinneret for spinning a deformed multifilament yarn in which a molten thermoplastic polymer is ejected from a plurality of ejection holes and the cross section of the fiber has a substantially equilateral triangle shape,
The discharge hole is formed of three slit holes having the same shape extending from the center (O) by diverging in three directions in a Y-shape by gradually reducing the slit width from the center (O) and forming a 120 ° included angle. ,
Further, semi-circles each having a radius of curvature (R) are processed at the three apexes (A, B, and C) forming the respective ends of the slit holes branched in three directions,
A dimensional ratio (R / L) between the radius of curvature (R) and the length (L) of the line segment connecting each vertex (A, B, and C) from the center (O) is 1/8 to 1 / In the range of 12,
A midpoint (M) of each side of an equilateral triangle formed by connecting the vertices (A, B and C) with straight lines, and a line segment MO connecting the midpoint (M) and the center (O). When a point (N) at which the outline of the discharge hole intersects is assumed, a dimensional ratio (l ₁ / l) between the length of the line segment OM (l ₁ ) and the length of the line segment ON (l ₂ ) ₂ ) is in the range of 2.8 / 2 to 3.2 / 2, a spinneret for deformed section yarns.   The spinneret for a modified cross-section fiber according to claim 1, wherein the Y-shaped discharge hole has an equal distance from the Y-shaped central portion to each tip, and can spin a regular cross-section shaped cross-section fiber.