KR840000635B1 - Making method and apparatus in filament fiber's nonwoven fabric - Google Patents

Abstract

A filament fiber is sucked into an ejector, and piles up taking the form of a web. A continuous multi-stage expansion device(5) is attached to the nozzle(4) of an injection pipe(3). Filament fiber is largely diffused by this device. Therefore, the piled filament fiber is formed into parabolashape and a bell-shape. Also, the intensity of a nonwoven fabric becomes constant both lengthwise and breadthwise.

Description

Manufacturing method of long fiber nonwoven fabric and apparatus therefor

1 shows a pattern in the case of dropping the inside of the filament to the deposition surface by the "ejector" of the circular cross section which is usually used,

2 shows a pattern of a state in which each filament is affected by adjacent filaments when the "ejector" of the cross-section circular used is arranged in a line perpendicular to the web deposition progression direction.

FIG. 3 shows the deposition pattern in the filament resulting from applying the method and apparatus of the present invention to each "ejector" in the case of FIG.

FIG. 4 (a) is a cross-sectional view of the "ejector" to which the diffusion apparatus used in the present invention is connected, and FIG. 4 (b) is a cross-sectional view of the same A-A cross section.

* Explanation of symbols for main parts of the drawings

1: high pressure air inlet 2: ejector inlet

3: ejector injection pipe 4: injection hole

5: multi-stage diffusion device

The present invention is a method for producing a long-fiber (filament) nonwoven fabric by a continuous filament fiber bundle is sucked by an ejector on the surface of the moving sediment to form a web, there is little difference in strength in the longitudinal direction It is an object of the present invention to provide an improved method and apparatus thereof.

In order to make a wide nonwoven fabric using a conventional ejector, the ejector or the filament fiber bundle by the ejector is reciprocated in the web width direction, or the ejector is arranged in one or more rows throughout the web width. Arrangement methods have been used.

However, in the former case, not only a complicated device is required to reciprocate the ejector and the like, but also the manufacturing conditions, that is, the reciprocating motion at a considerable speed in order to manufacture a wide uniform web when the deposition velocity reaches several tens of micrometers per minute Is actually difficult to manufacture. In the latter case, a complicated device such as the former is not necessary, but there is a problem of obtaining an anisotropic nonwoven fabric in which the longitudinal strength of the nonwoven fabric produced is greater than the lateral strength.

Therefore, recently, in order to solve the above problems, a method of inserting a non-circular cross-section diffuser into the lower part of the ejector ejection tube in the latter case, such as Japanese Patent Publication No. 53-147875, has been proposed. In addition, there is an inconvenience in that the position of the diffuser must be adjusted individually, and the cross section of the diffuser cannot be fixed to a certain shape, and at that time, an appropriate shape must be selected and used.

The present inventors have found that the latter problems do not form an isotropic circular pattern when the ejected air to each ejector reaches the web deposition surface, but rather collide with the unfolding in the transverse direction of the deposition surface by striking the air of ejectors adjacent to each other. This decrease was found to be the main cause. In other words, the distribution of the filament passing through the ejector is not uniform, and the closer to the center, the more filaments are deposited. It is necessary to narrow the ejector spacing so that the boundary of ejector classification overlaps with each other. As a result, the filaments ejected with air from the ejector are obstructed by the classification of adjacent ejectors in the width direction, and the spreading in the width direction becomes smaller, and consequently the web advancing direction. As a result, an elliptical pattern having a long axis was formed, and the entanglement in the web direction was reduced, so that the strength in the width direction was smaller than that in the longitudinal direction.

Based on the above problems and facts, the present inventors attach a multi-stage spreading apparatus having a circular cross section at the end of the ejector's ejection tube to reduce the influence of adjacent ejector airflow and increase the diffusion force of the filament ejected at the same time. Invented an improved method and apparatus for producing a long-fiber nonwoven fabric having a uniform filament distribution with little strength difference in the longitudinal direction and no weight half per unit area. The present invention will be described in detail with reference to the accompanying drawings. As follows.

As shown in FIG. 4, in the present invention, the apparatus of the present invention is constructed by installing a continuous multistage spreading device 5 having a circular cross section outside the end of the ejection opening 4 of each ejector 3 of the ejector. By using the device, the longitudinal cross-sectional shape of the filament fiber bundle falling on the deposition surface by increasing the diffusion force of the filament fiber bundle at the end of the ejector is a parabolic shape from a triangular to an elliptical to a circular shape. According to the present invention, a web with almost no difference in strength in the longitudinal and transverse directions can be obtained by making it vertical. Examples of the present invention are as follows.

EXAMPLE

24 filaments (total fineness 96 denier) per ejector having a diameter of d = 6 mm were sucked at an ejector air pressure of 6 kg / cm ² and dropped and deposited at right angles on a web deposition surface running at a speed of 2 m per minute.

The result of measuring the ratio of the longitudinal and horizontal strength of the web obtained by installing the multistage diffuser 5 according to the present invention under various different conditions on the outer side of the injection port 4 side end of the injection pipe 3 of the ejector is shown in the following table. It was like

Unit: θ is degree, L is mm

In the above table, the angle θ is the angle at which the inclined inner wall surface of the angular spreading device forms the upper inner wall surface, and L is the vertical length of the inclined wall surface of the angular spreading device.

In the above table, the following facts can be confirmed.

(1) The difference in longitudinal / lateral strength of the web is smaller when the diffuser is installed (Sample No. 1-9) than when there is no diffuser (Sample No. 10).

(2) In the case of attaching one diffuser (single type) (Sample No. 7-8), and attaching the multistage (e.g. three-stage) diffuser with proper control of the range of L and θ (Sample No. 1-3) ) Has a smaller transverse intensity difference.

종/횡 강도비가 1에 가까울수록 종/횡강도차는 적고 따라서 웨브는 등방성(等方性)을 나타낸다.

The closer the ratio of longitudinal / lateral strength is to 1, the smaller the longitudinal / lateral strength difference, and thus the web is isotropic.

(3) As a result of various experiments, it was found that the appropriate ranges of L and θ were as follows.

0 ° <θ ₁ , θ ₂ , θ ₃ . … <30 ° 5 ° <θ ₁ + θ ₂ + θ ₃ . … <35˚

2d 5d<L₁+L₂+L₃+……<50dL ₁ , L ₂ , L ₃ . …

2d 5d <L ₁ + L ₂ + L ₃ +... … <50d

As described above, according to the present invention, it is not necessary to prepare the diffusion device in various forms, and an isotropic web can be obtained without the need to adjust the installation position of the diffusion device at any time. In the same way, uniformity in quality can be achieved.

In the practice of the present invention, a unit spreading device may be used in which two or more units are formed continuously, but about three units are relatively simple in structure and suitable in effect.

Claims (3)

In manufacturing a long fiber nonwoven fabric in which a diffusion device is installed at the end of the ejection opening 4 of the ejector tube 3 of the ejector, the filament fiber bundle is deposited through the multistage diffuser 5 having a circular cross section. A method for producing a long fiber nonwoven fabric characterized by drop deposition on a surface. In the long-fiber nonwoven fabric production apparatus in which the diffusion device is installed at the end of the injection port 4 of the ejector pipe 3 of the ejector, the diffusion device is a circular cross-section and a two-stage or two-stage multistage diffusion device (5). Apparatus for producing a long fiber nonwoven fabric characterized in that it is formed continuously while gradually increasing the inclination angle of the wall surface. The apparatus for producing a long fiber nonwoven fabric according to claim 2, wherein the diffusion angle [theta] and the vertical length L of each unit diffusion device are within a range satisfying the following conditions. next 0 ° <θ ₁ , θ ₂ , θ ₃ . … <30 ° 5 ° <θ ₁ + θ ₂ + θ ₃ . … ≤35˚ L ₁ , L ₂ , L ₃ . … ≧ 2d 5d <L ₁ + L ₂ + L ₃ +... … 50d In the above, θ denotes an angle at which the inclined wall surface of each unit diffuser forms a wall formed in front of the inclined wall surface, and L denotes the vertical length (height) of the inclined wall surface of each unit diffuser.

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