JPH05125649A - Production of continuous filament web - Google Patents

Abstract

PURPOSE:To obtain the subject beltlike product having a normal distribution of basis weight in the width direction by providing a specific flow rectifying hood under air guns and controlling opened filament streams from the air guns. CONSTITUTION:A flow rectifying hood 3 having a structure in which two platy units are placed parallel and opposite to each other are initially installed in the width direction of a screen belt 5 and three or more air guns (2a) to (2f) are arranged at a regular interval in one row above the flow rectifying hood 3. Both ends of the air gun row are the air guns (2a) and (2f) jetting only air. Electrified filament bundles 1 of no twist are then jetted from the air guns (2b) to (2d), pulled, conveyed and simultaneously opened by the mutual electric repulsive force of the electrified filaments and diffusing action of the jetting air jets. The opened filament streams are subsequently passed through the flow rectifying hood 3 and only the air is simultaneously made to flow from the air guns (2a) and (2f) at both ends to control the filament streams, which are finally collected with a screen belt 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention opens a charged, substantially untwisted, continuous multifilament bundle by electrostatic repulsion of electricity and a diffusion action of an air jet ejected from an air gun, and a screen below. A method for collecting on a belt to produce a continuous filament web.

[0002]

2. Description of the Related Art The basic method of opening and collecting a charged continuous multifilament bundle to form a continuous filament web has been already known in Japanese Patent Publication No. 37-4993. The continuous filament web thus obtained exhibits high tensile strength and high tear strength by forming a spunbonded non-woven fabric by adhesively bonding the filaments by an appropriate method, and it is used in a very wide range of applications. It has reached the height of the spunbond business today. Like this
In order to produce a spunbond that can be put to practical use, it is necessary to have a technique for obtaining a collected continuous filament web having a width of several meters. For that purpose, it is necessary to open a large number of multifilament bundles and arrange them in the width direction of the collecting device so as to obtain a desired web width. An air gun (sometimes referred to as an air sucker or an air jet) is generally used for pulling, opening, and transporting the continuous multifilament bundle, but a multifilament bundle that can be processed by one air gun is used. There is a limit to the thickness and the number of filaments, and in order to obtain a wide web of several meters as described above,
It is necessary to arrange a large number of air guns in the width direction of the collecting device and pull a large number of multifilament bundles to open and collect the fibers.

The use of such a large number of air guns is described in Japanese Patent Publication No. 37-4993, but as a full-scale proposal, there is Japanese Patent Publication No. 42-23998. In this proposal, when a large width web is obtained by arranging a number of air guns, the continuous filament web opened and collected in individual air gun units, that is, in individual multifilament bundle units, has a normal distribution (Gaussian distribution) in the width direction. ) The weight distribution is at least 67%
The above-mentioned weighting is essential for uniforming the basis weight distribution of the obtained wide continuous filament web. This proposal also shows the optimization of the shape of the suction portion of the collector for controlling the orientation direction of the filaments in the continuous filament web.

[0004]

In the study of the present inventors, in order to realize a uniform basis weight distribution in the width direction, the width of a continuous multifilament web that has been opened and collected in individual multifilament bundle units. We acknowledged that overlapping directions is important. On the other hand, on the other hand, according to the study by the present inventor, the charged multifilament bundle jetted and conveyed from the air gun drastically decreases in speed as it is sufficiently opened by the electric repulsion force and the diffusion action of air. ,
It was clarified that the collecting position (falling position on the screen belt) easily fluctuated in the width direction of the collecting machine due to the air flow generated by the peripheral equipment in the room flowing around, causing meandering and not being stable.

As a result, the overlap of the webs in the width direction varies, and as a result, a disadvantage occurs in that the weight distribution of the webs in the width direction is disturbed. On the other hand, a reflection plate is installed below the air gun to control the position where it falls onto the collector, and a swinging device is installed below the air gun so that the filament group extends in the width direction of the collector or at an angle to it. There is a proposal for improvement in a method of swinging with the use of a device in which a pair of reflecting dispersion plates curved in an arc shape are arranged facing each other under the air gun (Japanese Patent Publication No. 2-462).

However, these methods also have the following drawbacks. That is, in the first method, the opened filaments vibrate when they fall into the collecting device, and ripples and fine streaks tend to be generated in the width direction of the obtained continuous filament web. In the second method, since it is necessary to increase the number of swings of the rocking device as the traveling speed of the collecting device increases, it is not suitable for high-speed molding because of the strength limitation of the rocking device.

Further, in the third method, among a large number of air guns arranged in the central portion, it is certain that the dropping position of the spread filament does not change due to the influence of the disturbance air. However, there is a problem that the dropping position of the spread filament that is pulled, spread, and conveyed by the air guns at both ends easily changes due to the disturbance air.

[0008]

The present inventor has arrived at the present invention as a result of various studies in order to solve the above-mentioned drawbacks of the prior art.

That is, according to the present invention, a charged and substantially non-twisted multifilament bundle is pulled and conveyed by an air gun, and at the same time, the electric repulsive force between the charged filaments and the diffusion action of the jetting air jets open the fibers. A method for producing a continuous filament web by collecting on a screen belt, the upper part of a straightening hood having a structure in which at least three air guns face each other in parallel in the width direction of the screen belt. This is a method for producing a continuous filament web in which the air guns at both ends of the air gun row are jetted out of air, and the air filaments are allowed to pass through the straightening hood while being arranged in a row at substantially equal intervals.

Further, preferably, the distance C between the two plates constituting the straightening hood, which face each other in parallel, and the distance P between the air guns are in the relationship of the following formula (1), and the air guns at both ends for ejecting only air are used. air flow a ₀ of the other air gun air flow rate a ₁ of is the above described continuous filament web manufacturing method characterized in that a relationship of the following equation (2). 1.5P ≧ C ≧ 0.5P (1) 2A ₁ ≧ A ₀ ≧ 0.5A ₁ (2)

The charged, substantially non-twisted multifilament as used in the present invention is essentially a multifilament in which "real twist" does not occur, that is, a twisted yarn or the like is not treated, and a high voltage is applied. It is charged with static electricity by corona discharge treatment and friction charging treatment. Therefore, the material excludes metal fibers and carbon fibers that show conductivity, but other organic, inorganic, synthetic, and chemical fibers, generally polyester, polyamide, polyolefin, polyvinyl alcohol, polyurethane. , Polycarbonate, aramid (wholly aromatic polyamide), polyarylate (wholly aromatic polyester), rayon and the like. The form of use is such that once wound up, it is unwound again and used, but it may be continuous to the process of spinning.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an example of an apparatus used for carrying out the method for producing a continuous filament web of the present invention. 2 is a front view of the apparatus shown in FIG. 1, FIG. 3 is a side view, and FIG. 4 is a plan view. In FIG. 1, 1 is a charged substantially non-twisted multifilament bundle. 2a, 2b, 2c, 2
Reference numerals d, 2e, and 2f are air guns, and in this example, 6 pieces are arranged in a row in the width direction of the screen belt 5 on the upper portion of the rectifying hood 4 at substantially equal intervals. Among the air guns, four of 2b, 2c, 2d, and 2e pull and convey the charged untwisted multifilament bundle 1, and at the same time, diffuse action of the jetted air jet that synergizes with the electric repulsive force between the charged filaments. The function of opening the charged filament into a monofilament state is exhibited.

The air guns 2a and 2f (hereinafter referred to as side guns) located at both ends are only jetted by an air jet without passing through the filament bundle. When the side gun is not used, the opening filament flow carried by the air jet ejected from the air gun easily changes its collection position and causes meandering even by the air flow generated by the peripheral equipment in the room. However, if side guns are used, the airflow flowing through the side guns may play the role of an air curtain. It is possible to collect without changing the. Therefore, the equipment of the side gun is indispensable. The air gun referred to in the present invention refers to JP-A-49-
It is the same as or similar to the filament take-off gun shown in Japanese Patent No. 66967.

Next, a reference numeral 3 in the drawing is a straightening hood having a structure in which two plate-like members face each other in parallel in the width direction of the screen belt, and the spread filament conveyed by an air jet ejected from an air gun. The flow passes through the straightening hood. The rectifying hood is necessary for the opening filament flow to stabilize the collection position on the screen belt-shaped collector, particularly the position in the traveling direction of the screen belt. That is, when the rectifying hood is not used, the air flow generated by the indoor peripheral equipment that flows around the sway causes the collection position to fluctuate back and forth in the traveling direction of the screen belt. Such a pattern is formed, which causes unevenness in the web length direction. Therefore, it is necessary to install a straightening hood having a structure in which two plate-shaped members face each other in the width direction of the screen belt and allow the spread filament flow carried by the air jet ejected from the air gun to pass through the straightening hood.

Next, in the present invention, it is more preferable to achieve the object that the distance C between the two plate-like members of the rectifying hood and the distance P between the air guns are in the relationship of formula (1), and the air is There is a case where the air flow rate A ₀ of the side guns at both ends ejecting only the air flow rate and the air flow rate A ₁ of the other air guns have a relation of the expression (2). 1.5P ≧ C ≧ 0.5P (1) 2A ₁ ≧ A ₀ ≧ 0.5A ₁ (2)

That is, when the relationship between the distance C between the two plate-like members of the rectifying hood and the air gun interval P is C <0.5P, which is narrower than a predetermined range, the flow of the opening filament flow of the rectifying hood is clogged. There is a case. On the other hand, when C> 1.5P, which is wider than the predetermined range, the opened filament flow 4 after passing through the hood may be partially biased to one side of the two plate-like bodies. This is due to the Counder effect of the air flowing in the rectifying hood. Also, the air flow rate A of the side gun
The relationship between ₀ and the air flow rate A ₁ of other air guns is A ₀ <
When it is smaller than the predetermined range of 0.5 A ₁ , ambient air causes a change in the collection position of the opening filament flow 4 after passing through the hood in the width direction of the screen belt collector. Correspondingly, the collecting sheet meanders and the basis weight of both ends of the web becomes abnormally small. It is considered that this is due to the decrease in the air curtain effect of sidens.

Meanwhile, the relationship between the air flow rate A ₀ side cancer the air flow rate A ₁ of the other air gun is larger than A _0> 2A ₁ and a predetermined range, side gun air open fiber filament flow adjacent its As it is pushed inward in the width direction, normally, as shown in 6 of FIG. 2 and 6 of FIG. 4, the thickness distribution of the collecting web in the width direction is almost normal for all air guns. , The part from the gun adjacent to the side gun, that is, both ends when viewed from the full width of the web may be abnormally high. Therefore, as a more preferable condition for achieving the object of the present invention, as described above, the distance C between the two plate-like members of the rectifying hood and the distance P between the air guns are set to 1.5 ≧ C ≧
And 0.5P, and an air flow rate A ₁ of the air flow A ₀ and the other air gun across the side gun for ejecting only air, 2
The relationship of A ₁ ≧ A ₀ ≧ 0.5A ₁ may be established.

As described above, according to the method of the present invention, as shown in FIG.
6 and 6 in FIG. 4, the spread filament conveyed by the air gun and passed through the rectifying hood has a collection position,
A long fiber filament web is stably manufactured with a constant collection width. The long-fiber filament web has a shape in which strip-shaped webs having a normal distribution areal weight distribution equal to the number of air guns excluding the side guns are arranged in the width direction. In addition, 6 of FIG. 2 and 6 of FIG. 4 are two side guns,
Since it illustrates the case using 4 other guns,
Four strips of normal distribution are lined up. This band-shaped web can be changed arbitrarily by changing the number of air guns,
It can be expanded to a few meters width practically required.

In practice, if a large number of normally-distributed strip-shaped webs are obtained in a wide width, the basis weight distribution is non-uniform in the width direction and has no practical value. However, as shown in FIG. 5, for example, 7, 8, 9 and 3 rows of air guns, and the normal distribution belt-like webs 10, 11, 12 obtained in each row are overlapped with each other with a shift of 1/3 of the distribution period in the width direction. When the webs are collected by arranging in such a manner, the superposed webs have a nearly uniform basis weight distribution in the width direction as shown in FIG. 6, and a wide filament fiber web which can be practically used can be obtained. If the number of rows of air guns is 2 or 4, similarly,
By shifting them by 2 or 1/4 and overlapping them, it is possible to obtain a substantially uniform basis weight distribution. The obtained long fiber filament web is subjected to a suitable method, for example, a calendar,
A non-woven fabric made of long fiber filaments can be obtained by "bonding", in which a sheet form is adjusted by forming adhesion or entanglement between fibers using a needle punch, a binder or the like and "bonding" to increase the strength.

According to the method of the present invention, a charged, substantially non-twisted multifilament bundle is opened by the electric repulsive force between the charged filaments and the diffusion action of the air jets ejected from the air gun, and the fibers are located below. When collecting on a screen belt type collector, use a rectifying hood composed of two plate-like bodies and use only air for the air guns on both sides of the air gun row arranged in one row in the width direction of the hood. By controlling the flow of the spread filaments ejected and conveyed from each air gun, the filament flow is collected stably and at a fixed position, and the belt-shaped long fiber filament web having a normal weight distribution in the width direction is obtained. Can be manufactured.

[0021]

EXAMPLES The present invention will now be described with reference to examples, but the present invention is not limited to these examples.
In the examples, the electrification voltage of the filament bundle was measured using a collector type potential measuring instrument FS-525 manufactured by Kasuga Electric Co., Ltd. The distribution of the basis weight in the width direction of the obtained web was evaluated by measuring the basis weight by cutting the web into a strip having a width of 1 cm and a length of 100 cm after bonding.

Examples 1 to 4 Using the apparatus shown in FIG. 1 and using PET fibers of 300 denier / 96 fil as a charged untwisted multifilament bundle, the conditions described in Table 1 (Examples 1 to 4) were used. A continuous filament web was produced. As shown in the results in Table 1, in these examples satisfying the present invention, the continuous filament web obtained without trouble during the manufacturing process was
It was evaluated that the collection position was stable, the width was constant, and that the fabric had a basis weight distribution in the width direction that almost coincided with the normal distribution, and was good.

Comparative Examples 1 to 4 Using the apparatus shown in FIG. 1 as in Examples 1 to 4, 300 denier / 300 denier as a charged untwisted multifilament bundle was used.
An attempt was made to produce a continuous filament web under the conditions described in Table 1 (Comparative Examples 1 to 4) using 96fil PET fiber. None of these examples satisfy the present invention in terms of manufacturing conditions. As shown in Table 1, the results were unsatisfactory in the production process condition and the obtained continuous filament web state, and the evaluation was poor.

[0024]

[Table 1]

Examples 5 to 8 As in Examples 1 to 4, the charged untwisted multifilament bundles shown in Table 1 (Examples 5 to 8) were prepared using the apparatus shown in FIG. An attempt was made to produce a continuous filament web by using the same main production conditions as shown in Table 1. These were different from each other in the target charged non-twisted multifilament polymer materials, denier, and the number of filaments, but they satisfied the present invention. As the results are shown in Table 1, the process condition and the state of the obtained filament web were comparable to those of Examples 1 to 4 and evaluated to be good.

[0026]

As described in the above embodiments, according to the method of the present invention, an air jet for ejecting a charged substantially non-twisted multifilament bundle from the electric repulsion force between charged filaments and an air gun. When the fibers are opened by the diffusing action of the screen and collected on the screen belt-shaped collector below, 2
The use of a straightening hood composed of a single plate-like body and the flow of the opening filaments jetted and conveyed from each air gun by flowing only air to the air guns on both sides of the air gun row arranged in one row in the width direction of the hood. It is possible to produce a strip-shaped long fiber filament web having a normal areal distribution in the width direction by controlling the above-mentioned process to collect the filament flow stably and at a fixed position. When the obtained belt-shaped long fiber filament web is superposed by adjusting the overlapping degree in the width direction,
Since the distribution of the basis weight in the width direction is made uniform, it is possible to easily produce a long fiber filament web excellent in the uniformity of the basis weight in a wide width by expanding the distribution.

[Brief description of drawings]

FIG. 1 is a perspective view of an apparatus used for producing a continuous filament web of the present invention.

2 is a front view of the device shown in FIG. 1. FIG.

FIG. 3 is a side view of the device shown in FIG.

FIG. 4 is a plan view of the device shown in FIG.

FIG. 5 is a plan view of an apparatus for producing a wide continuous filament web having a uniform basis weight distribution in the width direction by stacking the continuous filament webs of the present invention in the width direction.

6 is a schematic cross-sectional view of a cross-sectional basis weight distribution of a wide continuous filament web obtained by using the apparatus of FIG.

[Explanation of symbols]

1 Charged non-twisted multi-filament bundle 2a, 2f Air gun (side gun) 2b, 2c, 2d, 2e Air gun 3 Straightening hood 4 Opened filament flow after passing straightening hood 5 Screen belt collector 6 Strip continuous filament web 7 , 8,9 Air gun row 10 Band-shaped continuous filament web obtained in the air gun row 7 11 Web in which the band continuous filament webs obtained in the air gun rows 7 and 8 are laminated in the width direction. 12 A web obtained by stacking three layers in the width direction of the strip-shaped continuous filament web obtained from the air gun rows 7, 8 and 9.

Claims (2)

[Claims] 1. A screen belt located below a charged substantially untwisted multifilament bundle, which is pulled and conveyed by an air gun and at the same time opened by electrical repulsion between the charged filaments and a diffusion action of air jets ejected. In the method for producing a continuous filament web by collecting the above, at least three air guns are provided at substantially equal intervals to the upper part of a rectifying hood having a structure in which two plate-shaped members face each other in the width direction of the screen belt. A method for producing a continuous filament web, characterized in that the filaments are arranged in a row, and at the same time, the air guns at both ends in the row of the air guns eject air only so that the spread filament stream passes through the straightening hood. 2. The air flow rate of the air guns at both ends for ejecting only air, and the distance C between the plate-like members facing in parallel of the two plates constituting the rectifying hood and the air gun interval P are in the following formula (1). The method for producing a continuous filament web according to claim 1, characterized in that A ₀ and the air flow rate A ₁ of the other air gun have a relationship of the following expression (2). 1.5P ≧ C ≧ 0.5P (1) 2A ₁ ≧ A ₀ ≧ 0.5A ₁ (2)