KR102183243B1 - Hollow Fiber Yarn Excellent In Sound Absorption Using Spinneret For Hollow Fiber - Google Patents

Abstract

The present invention relates to a hollow fiber having excellent sound absorption properties using a spinneret for a hollow fiber and, more specifically, to a hollow fiber consisting of at least one or more slits and consisting of a pair of asymmetrical protrusion units on an inner side of the spinneret adjacent to the slits.

Description

Hollow Fiber Yarn Excellent In Sound Absorption Using Spinneret For Hollow Fiber}

The present invention relates to a hollow fiber having excellent sound absorption properties using a hollow spinneret, and more specifically, a hollow fiber having an asymmetrical protrusion in the inward direction near the slit, and the hollow fiber manufactured by the spinneret has excellent shape stability. And has excellent sound absorption properties.

As a material related to sound absorption, various types of sound absorbers are used in a number of different fields to absorb sound. Known sound absorbing materials include open-cell materials such as glass wool, rock wool, sponge, felt or urethane foam; Porous materials such as porous sintered board, metallic fiber board or foam metal board; Open cell chalk board; A combination of sheet material and nonwoven sound absorbing material; Or certain films.

Glass wool or felt was used to absorb sound from the car's engine compartment. In this case, the sound absorbing coefficient may increase in proportion to the thickness of the sound absorbing material. The weight and cost of the sound absorbing material increase as the thickness increases.

Various sound-absorbing materials are used in electrical and electronic equipment. The reduction in size and cost of such equipment continues to be emphasized.

The porous sound absorbing material is reduced as sound waves vibrate the porous material and the sound energy is converted into thermal energy. The negative energy requires a medium for energy transfer, and is better transferred in a liquid or solid having a relatively close molecular distance than in air. In the air, the distance between air molecules is so large that sound energy is lost as sound is transmitted. However, in liquids and solids, the distance between molecules and molecules is close, so sound waves are not easily lost and are transmitted more easily. If you listen to the phone you used to make when you were young, you can hear the whispering sound from a distance that you cannot hear in the air.

Porous materials have good sound absorption at high frequencies, but low frequencies have little effect. For low-frequency sound absorption, an air layer on the back of the sound absorbing material such as a partition wall and a hollow layer improves the sound absorption effect.

Meanwhile, many studies have been conducted on hollow fibers as a porous sound absorbing material, and various methods of manufacturing hollow fibers having such characteristics have been proposed.

Korean Patent Laid-Open Publication No. 2011-0004418 relates to a porous sheet, and specifically discloses a multilayer sound-absorbing sheet including a film layer having through fine bores and openings, and a fibrous material layer disposed on the film layer.

In addition, Korean Registered Patent Publication No. 1426602 is a nonwoven fabric for automobile interiors that is configured to maximize heat insulation, sound absorption, sound insulation and waterproof functions, and has excellent moldability because it contains short PET hollow fiber, short LM fiber and short PP fiber. Therefore, it is disclosed that it is easy to manufacture a product in a mold and has the effect of improving productivity and product quality.

The above patent relates to a sheet bonded by a porous film layer and short fibers, and there is a need for improvement in securing an air layer that affects absorption by securing the hollowness of the short fibers and the space between the short fibers having two types of deformed cross sections. have.

In order to solve the above problems, an object of the present invention is to provide a hollow fiber having excellent hollow shape safety and sound absorption by using a hollow spinneret.

In order to solve the above problems, the present invention provides a hollow fiber having excellent sound absorption properties by using a hollow spinneret consisting of at least one slit and a pair of asymmetrical protrusions on the inner side of the spinneret adjacent to the slit. to provide.

In addition, the protrusion of the present invention has an asymmetrical semicircular shape, and an area (α) adjacent to the slit is divided by connecting a virtual line from the virtual center circle of the spinneret to the center of the bottom of the vertical section of the protrusion. Provides a hollow fiber with excellent sound absorption properties characterized by being larger than the other area (β).

In addition, the present invention provides a hollow fiber having excellent sound-absorbing properties characterized in that the ratio of the two areas of the protrusions is 4:6 to 1:9.

In addition, the present invention provides a hollow fiber having excellent sound-absorbing properties, characterized in that the adjacent length (a) of the slit and the protrusion is 1/2 to 1 times the height (b) of the protrusion.

In addition, the present invention provides a hollow fiber having excellent sound-absorbing properties, characterized in that the height (b) of the protrusion is 1/4 to 1 times the thickness (d) of the spinneret.

Hollow fiber using a hollow spinneret having an asymmetric protrusion in the inward direction near the slit according to the present invention is high hollow and has excellent shape stability, and thus has excellent hollowness and sound absorption properties.

1 is a cross-sectional view of a hollow spinneret according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail. First, in describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the subject matter of the present invention.

The terms'about','substantially', etc. of the degree used in the present specification are used at or close to the numerical value when manufacturing and material tolerances specific to the stated meaning are presented, and are used in the sense of the present invention. To assist, accurate or absolute figures are used to prevent unfair use of the stated disclosure by unscrupulous infringers.

The present invention relates to a hollow fiber having excellent sound absorption by a hollow spinneret. The spinneret is composed of at least one or more slits, and may be composed of a pair of asymmetrical protrusions on the inner side of the spinneret adjacent to the slit.

1 is a cross-sectional view of a hollow spinneret according to an embodiment of the present invention. Hereinafter, a detailed description of the spinneret, the shape of the hollow spinneret of the present invention is an annular shape, and the thickness (d) of the spinneret is constant. The thickness (d) of the spinneret is equal to the difference (q-p) of the radiuses of the outer and inner diameters. The number of slits may be usually 1 to 3, and in the case of two or more, the distance between the slits and the slits is not limited, but a constant one is preferable.

In addition, it is preferable that the width (c) of the slit is constant, but it does not matter that it increases at a constant rate toward the outside of the spinneret in consideration of the expansion rate of the melted spinning resin depending on the location. Typically, when spinning a polyester resin having an intrinsic viscosity of 0.640 dl/g, a width (c) of a slit of 0.2 to 1.5 mm may be used. At this time, the thickness (d) of the spinneret is preferably the same standard as the width (c) of the slit.

In addition, the protrusion 20 of the present invention has an asymmetric semicircular shape, and the slit of the two areas of the protrusion separated by connecting a virtual line 30 from the virtual center circle of the spinneret to the center of the bottom of the vertical section of the protrusion The adjacent area α is larger than the other area β.

In particular, it is preferable that the ratio of the two areas of the protrusions is 4:6 to 1:9.

In addition, the adjacent length (a) of the slit and the protrusion is less than or equal to the height (b) of the protrusion, preferably 1/2 of the height (b) of the protrusion, more preferably 2/3 or more.

In addition, the height (b) of the protrusion is preferably 1/4 to 1 times the thickness (d) of the spinneret. Since the thickness (d) of the spinneret is 0.2 to 1.5 mm, the height (b) of the protrusion is 0.05 to 1.5 mm. Therefore, the adjacent length (a) of the slit and the protrusion corresponds to 0.025 to 1.5 mm.

The present inventors hollow fiber is a step of spinning at a spinning polymer discharge amount of 700 to 800g/min in a unit cell using the spinneret, a spinning temperature of 250 to 300°C, and a spinning speed of 800 to 1,200m/min; Stretching at a draw ratio of 2.0 to 4.0; It is manufactured through the step of cutting into fineness 7-15De and fiber length 30-100mm.

As the spinning polymer, a polyester polymer having an intrinsic viscosity of 0.640 to 0.670 dl/g may be used.

The hollow fiber manufactured according to the present invention forms the main configuration of the sound absorbing material together with the binding yarn.

In general, sound transmission of the sound-absorbing material is transmitted through the pores and hits the material, more precisely, the hollow fiber, which is the skeleton of the material. The sound hit in this way vibrates the skeleton of the material, and in the case of the sound absorbing material, the material must vibrate well by the sound hitting the skeleton in order to absorb the noise.

Accordingly, the hollow fiber must be formed densely like a mesh in the path through which the sound passes, but if the density is too high, the sound cannot enter the interior of the material and is reflected, thereby deteriorating the sound absorption performance.

Therefore, in order to form the path of the sound according to the present invention, it is formed like a net, but the hollowness of the hollow fiber must be increased so that the hollow fiber, which is the skeleton of the material, can vibrate well by noise while increasing the path of the sound. It should have shape stability enough to maintain the hollow ratio.

Features and other advantages of the present description as described above will become more apparent from the examples to be described later, and the following examples are described for illustrative purposes only and cannot be construed as limiting or limiting the protection scope of the present invention. .

Examples 1 to 2

Intrinsic viscosity of 0.640dl/g polyester, the number of slits is 3, the adjacent length (a) of the slit and the protrusion is 0.1mm, the height of the protrusion (b) is 0.2mm, the width of the slit (c) is 1mm, The thickness (d) is 1.2mm, the length (e) of the protrusion is 1.5mm, and the two areas of the protrusions separated by connecting a virtual line from the virtual center circle of the spinneret to the center of the bottom of the vertical section of the protrusion (α : After spinning at a spinning speed of 1,000m/min at a spinning temperature of 285℃ using a spinneret with a ratio of: β) of 6:4 and 9:1, the short fiber fineness is 15De and the fiber length is 64mm after stretching at a draw ratio of 3.8. Was prepared.

Example 3 to 4

Intrinsic viscosity of 0.640dl/g polyester, the number of slits is 3, the adjacent length (a) of the slit and the protrusion is 0.2mm, the height of the protrusion (b) is 0.4mm, the width of the slit (c) is 1mm, The thickness (d) is 1.0mm, the length (e) of the protrusion is 4mm, and the two areas of the protrusions separated by connecting a virtual line from the virtual center circle of the spinneret to the center of the bottom of the vertical section of the protrusion (α: After spinning at a spinning speed of 1,000m/min at a spinning temperature of 285℃ using a spinneret with a ratio of β) of 6:4 and 9:1, the fiber with a single fiber fineness of 15De and a fiber length of 64mm after spinning at a draw ratio of 3.8 Was prepared.

Comparative Examples 1-4

The adjacent length (a) of the slit and the protrusion, and the area ratio (α: β) of the two protrusions are shown in Table 1, and the rest are the same as in Example 1.

* How to measure sound absorption

The PET hollow fibers prepared in the above Examples and Comparative Examples and LM PET, which is a binding thread, are mixed at a weight ratio of 70:30.

It was measured using an equipment conforming to ISO 354 (KS F 2805: measuring method of sound absorption in the reverberation room). The size of the test piece is 1.0m x 1.2m, the reverberation time is when it is attenuated by 20dB compared to the initial eup pressure, and the sound source is a 1/3 Octave band sound source. The frequency range was measured for sound absorption in the range of 0.8 to 8 kHz.

division Example Comparative example One 2 3 4 One 2 3 4 radiation
Detention Adjacent of slit and protrusion
Length(a)(mm) 0.1 0.1 0.2 0.2 0.02 1.7 0.2 0.2 Protrusion
Height(b)(mm) 0.2 0.2 0.4 0.4 1.0 3.4 0.4 0.4 Area ratio of two protrusions
(α: β) 6:4 9:1 6:4 9:1 8:2 7:3 5:5 0 Hollow ratio (%) 32.0 35.1 36.2 40.2 29.2 30.5 30.8 31.0 Sectional break rate (%) 4.2 3.5 2.5 0.5 5.3 7.3 6.8 8.5 Reverberation chamber method sound absorption coefficient (a) frequency
kHz 0.8 0.90 0.92 0.93 0.95 0.51 0.79 0.81 0.84 1.0 0.80 0.82 0.82 0.84 0.48 0.66 0.70 0.76 1.25 0.75 0.80 0.81 0.86 0.46 0.64 0.67 0.68 1.6 0.76 0.79 0.80 0.85 0.46 0.62 0.67 0.67 2 0.75 0.78 0.78 0.84 0.46 0.60 0.64 0.66 2.5 0.75 0.76 0.75 0.81 0.44 0.58 0.62 0.66 3.15 0.74 0.76 0.75 0.80 0.41 0.57 0.61 0.62 4 0.71 0.74 0.74 0.77 0.39 0.54 0.59 0.61 5 0.70 0.73 0.73 0.78 0.38 0.53 0.58 0.59 6.3 0.69 0.72 0.70 0.78 0.38 0.52 0.54 0.58 8 0.68 0.69 0.71 0.76 0.36 0.22 0.53 0.57

In the present invention, the spinnerets are divided into two to four by 1 to 3 slits, and the spinnerets are separated at equal intervals by slits. The discharged resin expands due to the difference in pressure before and after spinning, and the presence of protrusions in the spinneret near the slit can increase the amount of polymer discharged at the junction of the spinneret. It is easy to combine with spinning resin. Therefore, it is possible to reduce the cracking of the cross section and eventually maintain the shape stability of the spun hollow fiber.

In Table 1, the adjacent length (a) of the slit and the protrusion and the area ratio (α: β) of the two protrusions are the most important, and the adjacent length (a) of the slit and the protrusion is related to the height (b) of the protrusion.

In Comparative Example 1, the protrusion is present at a site substantially adjacent to the slit.If the protrusion is too close in relation to the adjacent distance and the expansion rate of the spinning resin due to an increase in the amount of polymer discharged to the site to be bonded to the resin after spinning, the volume of the bonded portion increases and increases. The resulting volume is directed to the inside of the hollow fiber, resulting in a smaller hollow ratio. On the contrary, in Comparative Example 2, the adjacent length (a) of the slit and the protrusion is too large to affect the bonding of the joint even by expansion of the spinning resin.

The present invention is excellent in the effect when the area of the protrusion is asymmetrically widened toward the slit. In Comparative Example 3, the area ratio (α: β) of the two protrusions was out of the range of 4:6 to 1:9 of the present invention, and Comparative Example 4 did not have any protrusions, and the hollow ratio was not better than that of the Example. Can be seen.

Accordingly, in the embodiment of the present invention, the hollow ratio is superior to that of the comparative example, and an excellent effect in sound absorbing property related to the hollow ratio can be confirmed.

The present invention described above is not limited by the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those who have the knowledge of.

10: spinneret 20: protrusion
30: virtual line a: adjacent length of slit and protrusion
b: height of the protrusion c: width of the slit
d: Thickness of spinneret e: Length of protrusion
p: radius of inner diameter q: radius of outer diameter
α: Large area of protrusion β: Small area of protrusion

Claims (5)

Consisting of at least one or more slits,
Spinning using a hollow spinneret consisting of a pair of asymmetrical protrusions on the inner side of the spinneret adjacent to the slit,
The protrusion has an asymmetrical semicircular shape, and an area α adjacent to the slit is different from among the two areas of the protrusion divided by connecting a virtual line from the virtual center circle of the spinneret to the center of the bottom of the vertical section of the protrusion Hollow fiber with excellent sound absorption properties characterized by being larger than β).
delete The method of claim 1,
Hollow fiber excellent in sound absorption, characterized in that the ratio of the two areas of the protrusion is 4:6 ~ 1:9.
The method of claim 1,
The adjacent length (a) of the slit and the protrusion is 1/2 to 1 times the height of the protrusion (b).
The method of claim 1,
The height (b) of the protrusion is a hollow fiber having excellent sound-absorbing properties, characterized in that it is 1/4 to 1 times the thickness (d) of the spinneret.

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