JP2003138464A - Melt spinning assembly for nonwoven filament fabric, and method for producing the fabric using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a melt spinning assembly capable of preventing deposits around spinning holes on a spinneret, and to provide a method for producing a nonwoven filament fabric by using the same. SOLUTION: This melt spinning assembly comprises a spinneret (2) where no spinning holes and spinning holes are provided on the spinneret, the holes sandwiching the non-holes area in the center and divided into two rectangular subareas on both left and right sides, a cooling unit (3) for cooling filaments (F) spun through the spinning holes, and a gas sealing unit on the non-holes area for blowing an inert gas from right under the spinneret and having a blower (8) for blowing the inert gas to both sides of the rectangular subareas of the spinning surface of the spinneret (2) for sealing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melt spinning apparatus for melt spinning a thermoplastic polymer such as nylon or polyester, and a method for producing a long fiber nonwoven fabric using the melt spinning apparatus. More specifically, a melt-spinning device capable of stably spinning a large number of filaments, and a multifilament spun using the melt-spinning device are spread and placed on a moving collection net to form a long-fiber nonwoven fabric. The present invention relates to a long-fiber nonwoven fabric melt spinning apparatus and a method for producing the same.

[0002]

2. Description of the Related Art Generally, when melt-spinning a thermoplastic polymer such as polyamide or polyester, when the polymer is discharged from a discharge hole of a spinneret, a low polymer such as a monomer or an oligomer contained in the polymer is discharged. Is also discharged. The low-polymerization product discharged in this manner adheres to the periphery of the discharge hole, undergoes a thermal history for a long time, deteriorates and accumulates due to oxidation, and adheres and grows around the discharge hole.

In particular, when the "adhered matter" adhering to the periphery of the discharge hole grows to a certain size, it prevents the molten polymer from being discharged well from the discharge hole, causing undesirable causes such as bending, pulsation, and yarn breakage. Therefore, stable spinning becomes difficult. Therefore, it is necessary to regularly perform cleaning of the die surface, which is generally called "face sweeping", in order to remove these deposits. In that case, it is necessary to stop the spinning device and perform cleaning, which causes a problem that production efficiency is reduced.

Therefore, attempts have been made to prevent these from adhering to the die surface by flowing an inert gas under the die and constantly removing the atmosphere containing low-polymerized substances such as monomers and oligomers. Further, since the surface of the spinneret is sealed with an inert gas, it is possible to reduce the oxygen concentration, and there has been proposed an attempt to reduce "adhesion" deposited around the discharge holes of the spinneret.

For example, in Japanese Unexamined Patent Publication No. 2000-314031, a pressure equalizing chamber for blowing out an inert gas is provided just below the center of a circular spinneret, and nitrogen is introduced from a gas passage leading from a spinneret holder to the inside of the spinneret. To the pressure equalizing chamber,
An apparatus has been proposed in which nitrogen is radially blown from the pressure equalizing chamber to the discharge holes of the spinneret. Also, the actual Kaihei 5-8
In Japanese Patent No. 5862, a device is proposed in which an inert gas is blown toward the center of the spinneret from directly below the outer circumference of a circular spinneret.

Indeed, in the case of these devices, the discharge hole groups provided in the spinneret are concentrically arranged in the radial direction.
If they are arranged and drilled in about 3 rows, it is effective in reducing the oxygen concentration on the spinneret surface.

However, as in the case of producing a nonwoven fabric made of long fibers, the spinneret shape is rectangular, and the discharge hole group formed in the spinneret has a very high hole density, and a large number of discharge hole groups are formed. When the filament group is discharged, the effect is hardly recognized. This is because the inert gas supplied for sealing the die surface is carried away by the accompanying flow accompanying the polymer discharged from a large number of discharge hole groups, so that the sealing effect can be fully exerted. This is because it becomes difficult to keep the oxygen concentration below the base low.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art. That is, according to the present invention, even if a small amount of inert gas is supplied to the die surface, the die surface can be satisfactorily sealed, and the deposits can be deposited around the discharge hole group formed in the die. It is an object of the present invention to provide a melt spinning apparatus capable of reducing the number and a method for producing a long fiber nonwoven fabric using the same.

Further, it is an object of the present invention to provide a melt spinning apparatus which can improve not only the production efficiency but also the quality of the obtained nonwoven fabric, and a method for producing a long fiber nonwoven fabric using the same. And

[0010]

According to the present invention, "a non-perforated region where the polymer discharge hole group is not perforated and a perforated region where the polymer discharge hole group is perforated are formed on the polymer discharge surface. In addition, the perforated region is spun from a spinneret divided into two rectangular regions on the left and right sides of the non-perforated region in the center, and a polymer discharge hole group formed in the spinneret. A cooling device for cooling the filament group, and for blowing out the inert gas to the polymer discharge surface of the spinneret to seal the polymer discharge surface, in order to blow the inert gas directly under the spinneret. A melt-spinning apparatus for a long-fiber non-woven fabric having at least a blowout surface in the non-perforated region and at least a gas sealing device having an outward blowing device for blowing an inert gas toward both sides of the rectangular-shaped perforated region. "It is provided.

At this time, it is more effective to provide a gas sealing device having an inward blowing device for blowing an inert gas toward the non-perforated region on both outer sides of the perforated region, more effectively. Is preferable because it can be sealed with an inert gas.

Further, when the symbol N is the "perforation density (pieces / m ² )" of the polymer discharge hole group and the symbol W is the "short side length (m)" of the rectangular perforation region, The present invention is preferably applied to a melt spinning apparatus in which the spinneret simultaneously satisfies the conditions defined by the following formulas (1) and (2). This is because in such a spinneret, the sealing of the spinneret on the polymer discharge surface with an inert gas is particularly effective. 23000 ≤ N ≤ 60000 (1) 0.025 ≤ W ≤ 0.1 (2) Furthermore, the melt spinning apparatus for long-fiber nonwoven fabric of the present invention, a yarn take-up device for taking the filament group, More preferably, the filament group supplied from the yarn take-up device is used in an apparatus for producing a long-fiber nonwoven fabric including at least a moving net on which the filament group is spread and placed.

Further, as a method for producing a long fiber non-woven fabric, the production of the long fiber non-woven fabric composed of the filament group by using the non-woven fabric producing apparatus can produce a large number of filament groups in good condition. Is preferred.

In this case, it is preferable that the filament is a composite fiber composed of a two-component polymer of polyamide and polyester, because a long-fiber nonwoven fabric can be efficiently produced and brands can be diversified.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention described above will now be described in detail with reference to the drawings together with the operation thereof.

Here, FIG. 1 is a schematic front view (partially sectioned) of a nonwoven fabric manufacturing apparatus to which the melt spinning apparatus of the present invention can be preferably applied, and FIG. 2 is a spinneret. 3A and 3B are schematic plan views of the polymer discharge surface of FIG.

1 and 2, 1 is a spinneret pack, 2 is a spinneret, 3 is a cooling device, 4 is a yarn trading device, 5 is a collecting net, 6 is an embossing roller, and F
Indicates a filament group, respectively. Further, 7 is an inward blowing device for blowing the inert gas toward the center of the base, 8 is an outward blowing device for blowing the inert gas outward from the center of the base, and 9 is the inflowing inert gas. Enclosures for each are shown.

FIG. 1 shows the rectangular spinneret 2 shown in FIG. 2 as viewed from the short side direction. Therefore, the inward blowing device 7 and the outward blowing device 8 are provided with the blowing surface of the inert gas along the long side direction of the spinneret 2.

However, the "melt spinning device" of the present invention comprises at least a spinneret pack 1 incorporating a spinneret 2, a cooling device 3, and a yarn take-up device 4. Further, as a "gas seal device" for sealing the polymer discharge surface of the spinneret 2 with an inert gas,
At least the outward blowing device 8 is included, and more preferably, the inward blowing device 7 and the enclosing plate 9 are included.

Here, the spinneret 2 is composed of a plurality of plates configured to supply the polymer to the discharge hole group without uneven discharge. The plurality of plates and a pack component such as a filter for removing foreign matters in the polymer are fixed by the bolt group 10 shown in FIG. 2 and incorporated into the spinneret pack 1.

Further, the spinneret pack 1 is incorporated in a known spin block (not shown) having a heating device containing a heating medium, an electric heating device, or the like.
Then, the spinneret pack 1 in the spin block is produced by a known device (not shown) such as a gear pump that supplies a fixed amount of the molten polymer while measuring the molten polymer.
Is supplied to the spinneret 2 according to a conventional method of melt spinning.
From the filament group F.

The filament group F spun in this manner is solidified while being thinned while being cooled by the cooling air blown from the cooling device 3. Then, the cooled and solidified filament group F is sucked by the yarn drawing device 4 at a speed of 2000 m / min to 8000 m / min, and spread and placed on the moving collecting net 5. Then, it is supplied to an embossing roller in a state of being placed on the moving collection net 5, and is pressurized here to adjust the form as a long fiber nonwoven fabric.

At this time, the cooling device 3 includes the spinneret 2
The filament group F may be cooled by installing it on only one side of the filament group and sending cooling air from one direction. However, for the purpose of preventing the occurrence of cooling spots between the filament groups F, the cooling should be completed quickly. For that purpose, it is preferable to install the filaments on both sides and cool the spun filament group F from both sides. In particular, when spinning a very large number of filament groups F, it is preferable to blow cooling air from the outer peripheral side so as to surround the spun filament groups F for cooling.

The surrounding plate 9 is provided so as to surround the spinneret 2. In order to replace the air immediately below the spinneret 2 with an inert gas, the surrounding gas is surrounded by the inert gas. It is attached for the purpose of staying in the area. Further, to prevent air from entering the region directly below the spinneret 2, an air sucker device using compressed air is usually adopted as the yarn take-up device 4, and the compressed air is jetted in the suction direction of the filament group F. At this time, it plays a role of sucking the filament group F spun together with the air dragon sucked by the air sucker. Further, it also plays a role of supplying the sucked filament group F to the collecting net 5 together with the air flow.

The melt-spinning apparatus of the present invention constructed as described above is characterized by the provision of the gas sealing device for sealing the polymer discharge surface of the spinneret 2 with an inert gas. Therefore, this point will be described in detail below.

Here, the inward blowing device 7 is installed between the spinneret 2 and the cooling device 3 and is connected to a pipe (not shown) for supplying an inert gas, thereby supplying the inert gas. The source is adapted to supply the required amount of inert gas. Needless to say, an appropriate amount of the inert gas is supplied to the inward blowing device 7 by providing a flow control valve or the like. The inert gas referred to in the present invention refers to nitrogen, steam (steam), carbon dioxide, helium, etc. Among these, it is preferable to use nitrogen gas or steam (steam) because it is cheap and easy to obtain. .

The surface of the inward blowing device 7 for blowing out the inert gas may be a punching plate having a large number of small holes, a wire net, a porous sintered metal, or a combination of a plurality of these members. Can be used. However, what is important here is that the inert gas is blown out evenly over the entire blowing surface of the inward blowing device 7. Therefore,
For the purpose of achieving this, it goes without saying that any member that equalizes the pressure in the gas supply chamber of the inward blowing device 7 can be used without being limited to the member.

Further, the outward blowing device 8 is also installed in the lower portion of the spinneret 2, and the structure of the blowing portion of the inert gas may be the same as that of the above-mentioned inward blowing device 7. The inward blowing device 7 and the outward blowing device 8 are screwed to the spinneret 1 as shown in the drawing, or a well-known means such as a one-touch type clamp fixing is adopted, and the lower end of the spinneret pack 1 or It goes without saying that it can be fixed to the side.

In the inward blowing device 7 and the outward blowing device 8 having the above-described structure, the flow of the inert gas when the inert gas is blown from the blowing devices 7 and 8 will be described below.

In FIG. 1, as shown by the arrows, the blowing directions of the inert gas are the inward blowing device 7 and the outward blowing device 8.
Both are substantially horizontal, but immediately below the spinneret 2, the atmosphere is sucked by the accompanying flow generated by the filament group F to be a negative pressure. Therefore, the inert gas blown out from the inward blowing device 7 goes toward the mouthpiece surface.

However, it is preferable that the lower surface of the spinneret 2 incorporated in the spinneret pack 1 projects or is flush with the lower surface of the spinneret pack 1, but the spinneret 2 is provided in a depressed state. In the case where there is a step formed, it becomes difficult for the inert gas blown from the inward blowing device 7 to reach the mouthpiece surface. Therefore, in that case, the blowing direction may be inclined to the mouthpiece surface, or a deflecting plate or a rectifying plate may be provided to guide the inert gas so that the inert gas hits the mouthpiece surface.

The inward blowing device 7 and the outward blowing device 8
The wind velocity at the time when the blown out inert gas hits the filament group F needs to be suppressed to 2 m / sec or less. The reason is that when a wind velocity exceeding 2 m / sec collides with the filament group F, the filament group F sways or breaks, which prevents stable spinning. More preferably, it is suppressed to 1 m / sec or less.

By using the gas sealing device as described above, even if sublimated substances such as monomers and oligomers contained in the polymer are released into the atmosphere just below the spinneret 2, they are passed through an inert gas stream. Can be removed immediately. Therefore, air containing sublimates such as monomers and oligomers does not stay under the spinneret.

Therefore, it is possible to prevent sublimates such as monomers and oligomers from adhering and depositing around the polymer discharge holes formed in the spinneret 2. In addition, even if sublimates such as these monomers and oligomers slightly adhere and deposit around the discharge holes, the oxygen concentration is kept extremely low and the oxidation is suppressed because the inert gas is sealed right under the spinneret. It will not be done. Therefore, according to the present invention, it is possible to solve the conventional problem that a sublimate such as a monomer or an oligomer adheres to and accumulates around the ejection holes.

Next, as the spinneret 2 provided in the melt spinning apparatus of the present invention, when the polymer discharge surface is sealed with an inert gas, the spinneret 2 is particularly effective.
Is when the following expressions (1) and (2) are simultaneously satisfied. 23000 ≦ N ≦ 60000 (1) 0.025 ≦ W ≦ 0.1 (2) In the formulas (1) and (2), N is the perforation density (pieces / m ² ) of the spinneret 2. In the drawing, W indicates the length (m) of the short side of the perforated region.

Here, with respect to the above-described perforation density (the unit is "pieces / m ² ") and the length of the short side of the perforation area (the unit is "m"). Will be described in detail below with reference to FIG.

FIG. 2 exemplifies a schematic plan view of the spinneret 2, showing a polymer discharge surface. As is clear from this figure, the polymer discharge surface of the spinneret 2 has a rectangular shape, and at the center of the polymer discharge surface, as a region for installing the outward blowing device 8 along its long side direction. ,
The polymer discharge hole group has an unperforated region.

Then, there are two rectangular perforation regions in which the polymer ejection hole group is perforated by being divided into left and right through the non-perforated portion where the polymer ejection hole group in the central portion is not perforated. . Therefore, it goes without saying that the perforation density (N) and the length (W) of the short side of the perforation region are defined in the perforation region where the polymer discharge hole group is perforated.

The length (W) of the short side represents the length of each short side of the rectangular perforated area. In the case of FIG. 2, an example will be described. Although W has the same size, it is not limited to this and may have different sizes.

At this time, when N exceeds 60000 pieces / m ² , it means that the pitch between the discharge holes becomes narrow, and the cooling of the filament group F by the cooling device becomes insufficient, so that between the single yarns. Spinning cannot be performed due to fusion or the like.

On the other hand, when it is lower than 23000 pieces / m ² , the pitch between the discharge holes is widened, so that the inert gas easily passes between the filament groups F, so that the oxygen on the polymer discharge surface of the spinneret 2 is reduced. It becomes easy to reduce the concentration. However, when the number of discharge holes is reduced, the number of filament groups F spun out is reduced and productivity is deteriorated, which is not economical.

If W exceeds 0.1 m, it becomes difficult for the inert gas to pass between the filament groups F even if the perforation density is low, and the oxygen concentration on the polymer discharge surface cannot be reduced sufficiently. On the other hand, when W is less than 0.025 m, the oxygen concentration on the polymer discharge surface can be suppressed to a sufficiently low level without using the outward blowing device 8 of the present invention, but spinning is performed. It is not economical because the number of filament groups F decreases and productivity deteriorates.

Next, the method for producing the long fiber nonwoven fabric of the present invention will be described. In the method for producing a long fiber non-woven fabric of the present invention, the spun filament group F is taken up by the yarn take-up device 4 using the non-woven fabric producing device using the melt spinning device shown in FIG. After the filament group F is spread and placed on the net, the filament group F is supplied to an embossing roller to manufacture a nonwoven fabric.

In this case, as the production method of the present invention, a filament non-woven fabric is produced by using a filament made of polyamide or a filament made of a composite fiber or a mixed fiber made of a two-component polymer of polyamide and polyester. Is effective. This is because in melt spinning of filaments containing at least polyamide, the amount of "adhesion" around the discharge holes of the spinneret 2 is large, and the surface sweep period is shortened.

Further, when the oxygen concentration just below the spinneret 2 varies, the "adhesion" consisting of sublimates such as monomers and oligomers is extremely small at the low oxygen concentration, and therefore stable. Spinning is possible,
At locations where the oxygen concentration is high, it is necessary to perform surface sweeping because bending and yarn breakage frequently occur due to "adhesion".

That is, 2 of polyamide and polyester
When manufacturing a continuous fiber non-woven fabric composed of composite fibers or mixed fibers composed of component polymers, even if the oxygen gas concentration varies even if the area directly below the spinneret 2 is sealed with an inert gas, the surface sweep cycle is improved. Not enough effect to get.

However, by using the gas sealing device attached to the melt spinning apparatus of the present invention, the inert gas is blown from the central portion and the outer peripheral portion of the spinneret 2, and the accompanying flow of the filament group F is generated. By utilizing this, it is possible to uniformly seal with an inert gas without causing unevenness in the oxygen concentration immediately below the spinneret 2.

When the polymer discharge surface of the spinneret 2 is swept, the cooling devices 3 provided on the left and right in FIG. 1 are manually removed, or a known mechanism such as a link mechanism or a cylinder is used. , Automatic and temporary removal.
By doing so, a working space for sweeping is secured,
The surface of the spinneret 2 can be swept.

[0049]

EXAMPLES Example 1 Using a long fiber nonwoven fabric manufacturing apparatus including the melt spinning apparatus illustrated in FIGS. 1 and 2, the perforation density N is 38000 / m ² , and the length of the short side of the perforation region is set. W is 0.05m and the long side is 2.0m,
Moreover, the spinneret 2 having a total number of discharge holes of 7600 was used. Then, the amount of polymer discharged from the spinneret 2 per discharge hole is 1.2 g / min, and the drawing speed of the filament group F in the yarn drawing device 4 is about 3500 m / min. Blowing nitrogen from the blowing device 8
As a result of continuous production over time, there was little "adhesion" around the discharge holes, and no surface sweep was necessary.

[Comparative Example 1] In Example 1, when continuous production was carried out for 24 hours under the condition that the nitrogen blowing from the inward blowing device 7 and the outward blowing device 8 was eliminated, the growth of "adhesion" was rapid. There was a lot of bending and yarn breakage, and it was necessary to perform surface sweeping about every 6 to 7 hours, which not only caused a problem in productivity but also a defect in the quality of the nonwoven fabric.

[0051]

As described above, the melt spinning apparatus of the present invention,
And by the method for producing a long-fiber non-woven fabric using the same, in the case of producing a long-fiber non-woven fabric, it is possible to suppress the occurrence and growth of the "adhesion" around the discharge hole of the spinneret, so that the bending, It is possible to suppress the deterioration of the quality of the long-fiber nonwoven fabric due to yarn breakage or the like.

Further, even if a very large number of polymer discharge holes are formed in the spinneret, the melt spinning can be performed stably, so that not only the production efficiency of long-fiber nonwoven fabric is improved, but also the surface sweep cycle of the polymer discharge surface of the spinneret is improved. Since it can be extended, productivity is significantly improved.

Further, in the case of melt-spinning a polyamide simple substance or a composite fiber or a mixed fiber made of polyamide and polyester, the adhesion and deposition of sublimates such as monomers and oligomers released from polyamide on the spinneret surface are suppressed. Moreover, since the concentration of oxygen contained in the air can be reduced, stable yarn production can be achieved for a long period of time.

[Brief description of drawings]

FIG. 1 is a front view, schematically illustrating a melt spinning apparatus used for a long fiber nonwoven fabric manufacturing apparatus, with a partial cross section.

FIG. 2 shows a gas sealing device for a spinneret surface of the present invention and a spinneret used in a nonwoven fabric manufacturing facility using the device.

FIG. 3 is a sectional view taken along line XX in FIG.

[Explanation of symbols]

1 Spinneret pack 2 Spinneret 3 Cooling device 4 Thread take-up device 5 collection net 6 Embossing roller 7 Inward blowing device 8 Outward blowing device 9 Enclosure F filament group

Claims (6)

[Claims] 1. A non-perforated area where the polymer discharge hole group is not perforated and a perforated area where the polymer discharge hole group is perforated are formed on the polymer discharge surface, and the perforated area sandwiches the non-perforated area in the center. A spinneret divided into two rectangular regions on the left and right sides thereof, a cooling device for cooling the filament group spun from the polymer discharge hole group formed in the spinneret, and the spinneret. In order to blow the inert gas to the polymer discharge surface to seal the polymer discharge surface, the blowout surface for blowing the inert gas directly below the spinneret is provided in the non-perforated area, and the two A melt-spinning apparatus for long-fiber non-woven fabric, comprising at least a gas sealing device having an outward blowing device for blowing an inert gas toward both sides of a rectangular perforated region. 2. The melt spinning apparatus for long fiber nonwoven fabric according to claim 1, further comprising a gas sealing device having an inward blowing device for blowing an inert gas toward the non-perforated region on both outer sides of the perforated region. 3. The spinning, wherein N is a "perforation density (pieces / m ² )" of the polymer discharge hole group, and W is a "short side length (m)" of the rectangular perforation region. The melt spinning apparatus for long-fiber nonwoven fabric according to claim 1 or 2, wherein the spinneret simultaneously satisfies the conditions defined by the following formulas (1) and (2). 23000 ≦ N ≦ 60000 (1) 0.025 ≦ W ≦ 0.1 (2) 4. A long-fiber nonwoven fabric manufacturing apparatus including at least a yarn take-up device for taking up the filament group, and a moving net on which the filament group supplied from the yarn take-up device is spread and placed. The long-fiber nonwoven fabric melt-spinning apparatus according to any one of claims 1 to 3, which is used. 5. A method for producing a long fiber non-woven fabric, which comprises producing the long fiber non-woven fabric comprising the filament group by using the melt spinning apparatus according to claim 4. 6. The method for producing a non-woven fabric according to claim 5, wherein the filament is a composite fiber or a mixed fiber composed of a binary polymer of polyamide and polyester.