JPH0748716A - Conjugate fiber - Google Patents

Abstract

PURPOSE:To obtain a conjugate fiber, having high adhesive strength and good in quality without causing a gap in a boundary surface between modified cross- section core fiber and sheath fiber or peeling the sheath fiber. CONSTITUTION:This conjugate fiber is obtained by increasing the thickness dimensions on the outer peripheral side from those on the central side of each radial strip piece (1a) of core fiber 1 in conjugate fiber 3 composed of the modified cross-section core fiber 1 radially protruding the strip pieces (1a) and sheath fiber 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved composite fiber for nonwoven fabric.

[0002]

2. Description of the Related Art As one of the conventional composite fibers for a non-woven fabric, a core fiber 1 made of a modified polypropylene having a cross-section * shape and having strips 1a protruding radially as shown in FIG. There is a sheath fiber 2 made of circular polyethylene and a composite fiber 3 made of polyethylene.

By the way, the thickness dimension a of the core fiber 1 of the composite fiber 3 on the center side of the radial strip 1a and the thickness dimension b on the outer circumference side are substantially the same as a≈b. On the other hand, the polypropylene of the core fiber 1 and the polyethylene of the sheath fiber 2 have poor affinity. Therefore, a gap is generated on the boundary surface or the sheath fiber 2 is peeled off.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to provide a conjugate fiber having a high adhesive strength without causing a gap in the boundary surface or peeling of the sheath fiber.

[0005]

Means for Solving the Problems The composite fiber of the present invention for solving the above-mentioned problems is a composite fiber composed of a core fiber and a sheath fiber having a cross-section with a radially outwardly protruding strip shape, and a core fiber. The thickness of the outer circumference is larger than the thickness of the radial strip of FIG.

[0006]

As described above, in the conjugate fiber of the present invention, since the thickness of the core fiber on the outer peripheral side is larger than the thickness of the radial strip of the core fiber on the outer peripheral side, the outer periphery of the core fiber having an irregular cross section is formed. The surface and the deformed inner peripheral surface of the sheath fiber are in close contact with each other, there is no gap in the boundary surface, the polyethylene of the sheath fiber does not peel off, and the adhesion is high and the quality is good. is there.

[0007]

EXAMPLE An example of the conjugate fiber of the present invention will be described.
Cross-section with strips protruding in a hexagonal radial pattern as shown in Fig. 1 *
In a composite fiber 3 composed of a core fiber 1 made of a modified polypropylene and a sheath fiber 2 made of polyethylene of a circular shape, the radial band 1a of the core fiber 1 has a thickness greater than that of the center side of the core fiber 1. The thickened side.

In order to manufacture the composite fiber 3 of such an embodiment, as shown in FIG. 2, the hexagonal radial discharge holes 7 of the molten polypropylene 6 which become the core fibers 1 of the intermediate plate 5 of the spinning device are shown in FIG. The width of the slit hole 7a on the outer peripheral side is made larger than the width on the center side, and the molten polypropylene fibers discharged from the discharge hole 7 are discharged into the space between the discharge hole 8 of the intermediate plate 5 and the spinning plate 9. It is surrounded by molten polyethylene 10 and introduced into the introduction hole 11 of the spinning plate 9, narrowed down to the discharge hole 12 ahead of it, and discharged and spun from the tip opening. If the inner surface of the discharge hole 7 of the intermediate plate 5 is finished by electrical discharge machining, the surface becomes rough and the surface of the molten polypropylene fiber discharged from the discharge hole 7 can be roughened. Meshes with the surface of the molten polypropylene fiber, so that the composite fiber 3 finally discharged and spun from the discharge hole 12 of the spinning plate 9 has a mechanical bonding strength.

As described above, in the conjugate fiber 3 of the embodiment, since the radial strip 1a of the core fiber 1 is thicker on the outer peripheral side than on the central side of the core fiber 1, the outer peripheral surface of the core fiber 1 and the sheath fiber 2 are It is in close contact with the inner peripheral surface of No. 3, no gap is formed at the boundary surface, the polyethylene sheath fiber 2 does not peel off, and the adhesion is high and the quality is good. The core fiber 1 has a shape in which the strips 1a project in a hexagonal radial shape, but may have a Y-shaped cross section, a dodecagonal shape, a star shape, or the like.

[0010]

INDUSTRIAL APPLICABILITY As described above, the conjugate fiber of the present invention has high adhesion and high quality without causing a gap in the boundary surface between the core fiber and the sheath fiber or peeling of the sheath fiber. Is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the conjugate fiber of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a spinning device for producing the conjugate fiber of FIG.

3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is a cross-sectional view showing an example of a conventional conjugate fiber.

[Explanation of symbols]

 1 core fiber 1a radial strip 2 sheath fiber 3 composite fiber

Claims (1)

[Claims] 1. A composite fiber comprising a core fiber and a sheath fiber, which have radial cross-sections with irregularly shaped cross-sections, and a thickness of the core fiber on the outer peripheral side of the radial band, which is closer to the outer peripheral side than the central side. A composite fiber characterized by having an increased size.