JPH1025650A - Production of spunbonded nonwoven fabric and opening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spunbonded nonwoven fabric excellent in opening, having uniform metsuke distribution and excellent in weave. SOLUTION: A continuous filament group 2 obtained by subjecting a thermoplastic resin to melt spinning in bamboo blind-like shape is drawn by a high- speed stream drawing device 32 having a rectangle cross section to carry out slenderizing drawing and the continuous filament group 2 is opened by a corona discharge electrode 5, a planer-like target electrode 7 and a guide plate 8 provided in the lower part of the high-speed stream drawing device 32. In this case, blocking plates 17 and 18 divided into small portions are installed between the high-speed stream drawing device 32 and planer target electrode and between the planer target electrode 7 and the guide plate 8. The weight of the nonwoven fabric is continuously measured in width direction of the nonwoven fabric by a weight-measuring device 14 and blocking plates 17 and 18 are moved in correspondence with a place partially having heavy weight or a place partially having light weight and filament density in the width direction of the nonwoven fabric is made uniform and deposited on a net conveyer 9 to provide the objective nonwoven fabric 12 having uniform weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for continuously producing a spunbonded nonwoven fabric comprising a continuous filament group. More specifically, the present invention relates to a method and an apparatus for producing a spunbonded nonwoven fabric having a uniform basis weight distribution.

[0002]

2. Description of the Related Art Spunbonded nonwoven fabrics are obtained by melt-spinning a thermoplastic resin into continuous filaments, which are thinned and drawn using a high-speed airflow traction device to reduce the distribution density of the continuous filaments inside and outside the high-speed airflow traction device. After making it even,
A method of applying static electricity by contact charging due to collision or friction or forced charging by corona discharge, opening each filament by mutual repulsion of filaments, depositing these on a net conveyor, and forming a nonwoven web at low cost In recent years, its demand has been increasing as a method for obtaining non-woven fabrics.
It has become important to obtain a technique for making the basis weight distribution of the nonwoven fabric uniform.

Various methods have been proposed to make the distribution of the continuous filaments uniform, and a continuous filaments melt-spun in a cord shape from a rectangular die having spinning holes arranged in a rectangular shape is drawn and introduced. , The cross section of the passing part is narrow,
The use of a high-speed airflow traction device having a wide rectangular cross section has been used as a method for obtaining a wide nonwoven fabric having no unevenness. This fiber opening method includes a method of diffusing an airflow accompanying a continuous filament group ejected from a high-speed airflow traction device and dispersing the multiplied by the diffusion of the airstream, triboelectric charging, and charging the same polarity to the continuous filament group by a corona discharge. And apply
Numerous methods have been disclosed, such as a method of opening the fiber by the repulsive force, a method of swinging the ejection opening of the continuous filament group to widen the dispersion width, and the like.

Generally, in order to obtain a uniform nonwoven web, it is necessary to completely open the filaments, and the opening is greatly affected by the magnitude of the repulsion caused by the static electricity between the filaments. Therefore, it can be said that the higher the charge amount, the greater the repulsive force due to static electricity and the better the fiber opening. It is also important whether or not the filaments are uniformly charged. If the filaments are not uniformly charged, the spread is poor. Therefore, it can be said that uniformly increasing the charge amount is a method for improving the spread state.

Attention is paid to the fact that the method of passing the filament group through the corona discharge electric field and charging the filament group by the corona discharge is stable, and a relatively good spread state can be obtained. However, when the number of filaments is increased or the running speed of the filaments is increased by the corona discharge opening method, the filaments are not completely opened and are in a bundle of several tens or more. Since the nonwoven fabric is deposited on a net conveyor, there is a problem that the obtained nonwoven fabric has extremely poor uniformity.

[0006] In each of these methods, it is sufficiently possible to individually disperse the constituent fibers of the continuous filament group, but the arrangement of the fibers in the local portion is disordered, and the obtained product is not easily dispersible. Looking over the entire area, it was difficult to suppress unevenness.

[0007]

When a high-speed airflow traction device having a narrow rectangular cross section and a wide rectangular cross section is used, a continuous filament group introduced in an interdigital shape is uniformly distributed in the width direction (width direction of the nonwoven fabric). Injecting with high-speed airflow requires advanced technology. For this purpose, it is necessary to finish the inside of the high-speed airflow traction device, especially the shape of the injection port, with high precision so as not to be distorted over the entire width of the long side. Increase maintenance costs. The larger the width, the more noticeable. In addition, due to contamination and thermal strain inside the high-speed airflow traction device due to operation, the continuous filaments also become non-uniform.

[0008] Therefore, as a result of intensive studies on whether a continuous filament has a good state of opening and a method of easily adjusting the basis weight is not possible, in the method of opening by corona discharge, a guide plate is provided below a flat target electrode, and a corona is provided. By providing a movable shielding plate for controlling the inflow and outflow of air above and below the discharge electrode, a method of adjusting the amount of air flowing into and out of the device, and a method of interlocking with the basis weight measuring device were devised. Was completed. The present invention
Production of a spunbond nonwoven fabric with a uniform basis weight distribution that solves the problems of known techniques for controlling the occurrence of poor opening and unevenness of the basis weight, and can reduce the unevenness of the continuous filament group by a simple operation. It provides a method.

[0009]

SUMMARY OF THE INVENTION The first aspect of the present invention is to draw and stretch a continuous filament group obtained by melting and spinning a thermoplastic resin from a spinneret into an interdigital shape by a high-speed airflow pulling device having a rectangular cross section. A method for producing a spunbonded nonwoven fabric, in which a group of interdigital continuous filaments conveyed together with an air flow from the high-speed airflow traction device is guided to a corona discharge unit including a corona discharge electrode and a plate-like target electrode to spread the filaments. A guide plate is provided substantially in parallel with the flat target electrode at a position below the flat target electrode and not in contact with the continuous filament group, and a gap between the high-speed airflow traction device and the flat target electrode and / or a guide between the flat target electrode and the flat target electrode. In the gap with the plate, a shielding plate subdivided in the width direction of the device, and a device for individually moving the shielding plate, A method for producing a spunbonded nonwoven fabric which is characterized by adjusting the gap partially varied by the movement of the shield basis weight.

[0010] A second aspect of the present invention is characterized in that an apparatus for continuously measuring the basis weight of the nonwoven fabric in the width direction is provided, and the shielding plate is movable in conjunction with a signal from the apparatus to adjust the basis weight. The method for producing a spunbonded nonwoven fabric according to the first aspect.

A third aspect of the present invention is to draw and stretch a continuous filament group in which a thermoplastic resin is melt-spun from a spinneret into an interdigital shape by a high-speed airflow traction device having a rectangular cross section. In the apparatus for producing a spunbonded nonwoven fabric, which guides a group of interdigital continuous filaments conveyed together with an air flow to a corona discharge unit composed of a corona discharge electrode and a flat target electrode, a continuous filament group below the flat target electrode. A guide plate is provided at a position not in contact with the plate-like target electrode substantially in parallel with the plate-like target electrode, and a gap between the high-speed airflow traction device and the plate-like target electrode and / or a gap between the plate-like target electrode and the guide plate is provided in the width direction of the device. Equipped with a shielding plate that is subdivided into a plurality, and a device that enables the shielding plate to be individually moved. An opening device of the filament group, wherein a partial adjustable possible.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing a spunbonded nonwoven fabric of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing an example of an apparatus used in the method for producing a spunbonded nonwoven fabric of the present invention, and FIG. 2 is an air channel, a flat target electrode, a guide plate, and a shield plate below the high-speed airflow traction device shown in FIG. FIG.

In FIG. 1, a continuous filament group 2 discharged from a spinneret 1 strikes a flat target electrode 7 through an ejector 3 and an air channel 4 and is forcibly charged by a corona discharge electrode 5 to be charged with static electricity. The continuous filament group 2 is opened by the repulsive force of the filaments and is placed on a net conveyor 9 in the form of a nonwoven web 10.
And heat-sealed at a number of points by a hot embossing roll 11 to form a nonwoven fabric 12, which is wound by a winder 13.

The method of opening fibers by corona discharge used in the present invention will be described. A plurality of filaments are spun from a rectangular spinneret 1 in the form of a blind.
Is guided into the corona discharge electric field by the airflow from the high-speed airflow traction device 32 (the ejector 3 and the air channel 4), and is passed along with the airflow. Filament in the present invention is a thermoplastic resin, is not particularly limited as long as it has a fiber morphology, polypropylene,
Resins such as polyethylene terephthalate, polyethylene, and nylon, or mixtures and copolymers thereof can be used. The filament may be a composite fiber or a mixed fiber composed of two or more resins, and the diameter and the cross-sectional shape are not particularly limited.

In the present invention, the continuous filament group 2 is passed through the corona discharge electric field together with the air flow and charged. The corona discharge method used in the present invention may be any known method. A corona discharge method comprising a discharge electrode (needle-shaped electrode) 5 and a flat target electrode 7 is generally preferable, and a voltage of usually -10 to -60 KV is applied between electrodes having an interval of 10 mm to 50 mm to perform corona discharge. Is generated, and the continuous filament group 2 is passed between the two electrodes. At this time, the applied voltage of the corona discharge is a limit voltage at which arc discharge does not occur, and depends on the distance between the needle electrode and the flat target electrode. Therefore, it is generally preferable to apply a voltage before arc discharge.

The needles of the needle-shaped electrode 5 of the present invention are preferably composed of a plurality of rows or a plurality of rows in order to advantageously charge the continuous filament group 2, and the needle density is preferably 2 to 1 in particular.
It is preferred to be composed of 0 / cm ² . Needle density 2 / c
If it is less than m ² , if the number of filaments is large, it is not preferable because charges for obtaining a good spread cannot be uniformly applied. If the needle density exceeds 10 needles / cm ² , an excessive charge is applied to the continuous filament group 2, and thus a discharge occurs between the continuous filament group 2 and the flat target electrode 7, or a discharge occurs in the air. Therefore, a phenomenon occurs in which the charge amount of the continuous filament group 2 is partially lost, which is not preferable. The arrangement of the needles is not particularly limited, but is more preferably arranged in a staggered manner.

The material of the needle electrode 5 is not particularly limited as long as it has electrical conductivity. The tip of the needle electrode 5 is preferably sharp, and the height of the tip of each needle must be adjusted. That is, if the tip of the needle-shaped electrode 5 is rounded or the height of the needle-shaped electrode 5 is different, the corona generated from the needle-shaped electrode 5 cannot be generated in a uniform and large range. As the material of the flat target electrode 7 used in the present invention, a hard material is suitable in terms of durability and stability because the continuous filament group 2 collides at a high speed, and a metal such as iron, chromium, nickel, or the like is suitable. Alloys such as stainless steel are preferred. The surface of the flat target electrode 7 is preferably smooth because the continuous filament group 2 slides on the flat target electrode 7.

Here, looking at the continuous filament group and the air flow passing through the corona discharge electric field, the air flow injected by the high-speed air flow traction device collides with the flat target electrode 7 at high speed, and the air flow proceeds downward. The speed of the flow decreases. At this time, the continuous filament group 2 is in close contact with the flat target electrode 7 for a while after colliding with the flat target electrode 7, but the force for holding down the continuous filament group 2 gradually decreases due to a decrease in the velocity of the air flow. The continuous filament group 2 also spreads. When a voltage is applied by the corona discharge electrode (needle-shaped electrode) 5 in this state, the continuous filament group 2 is charged and further spread by the repulsion of the static electricity, and the continuous filament group 2 rises from the surface of the flat target electrode 7. Leave.

When the charged continuous filament group 2 separates from the surface of the flat target electrode 7 and comes into contact with the flat target electrode 7 again, a part of the electric charge of the continuous filament group 2 is lost, and a good fiber opening is achieved. The amount of charge required to obtain it cannot be obtained. Therefore, the length of the flat target electrode 7 in the flow direction is equal to the length of the charged continuous filament group 2.
It is better not to be too long in order not to contact again, and it is preferable that the length is slightly larger than the length of the needle electrode 5.

The guide plate 8 is provided on the plate-like target electrode 7 side and downstream of the filament group 2 so as not to contact the continuous filament group 2, and the filament group 2 is moved toward the guide plate 8 side. It serves to draw the continuous filament group 2 into close contact with the flat target electrode 7. Further, the guide plate 8 is provided in parallel with the flat target electrode 7, but may be further inclined in a direction approaching the vertical in order to more reliably maintain the parallelism with the filament group 2. The distance between the extension of the surface of the flat target electrode 7 and the surface of the guide plate 8 is preferably 0.5 to 50 mm. If it is less than 0.5 mm, the filament group is
When it exceeds 50 mm, the suction effect of the guide plate hardly occurs, which is not preferable. The distance from the edge of the flat target electrode 7 to the edge of the guide plate 8 is determined by the size and angle of the flat target electrode 7 and the guide plate 8, the speed of the filament group 2, and the like.

Under such an arrangement, by applying a charge opposite to the charge applied to the continuous filament group 2 to the guide plate 8, the continuous filament group 2 charged by the needle-shaped electrode 5 is transferred to the guide plate 8. The continuous filament group 2 that has been drawn to the side and charged is brought into close contact with the flat target electrode 7 without being lifted from the surface thereof. By applying a voltage with the needle electrode in this state, a better formation can be obtained.

A high voltage of +30 KV or less is applied to the guide plate 8 of the present invention, and if a grounded conductor such as the plate-like target electrode 7 is in the vicinity, a discharge is generated between the conductors. In addition, it is necessary to install so as not to cause corona discharge with the flat target electrode 7. Accordingly, the distance between the flat target electrode 7 and the guide plate 8 for corona discharge may be arbitrarily set as long as no discharge occurs, but the charged continuous filament group 2 must not be brought into contact with the guide plate 8. That is, when the continuous filament group 2 is brought into contact with the guide plate 8,
This is because a part of the charge amount of the continuous filament group 2 is lost, and the charge amount necessary for obtaining a good spread cannot be obtained. Further, when a voltage exceeding +30 KV is applied to the guide plate 8, the distance between the plate-like target electrode 7 and the guide plate 8 is very long if the installation is performed so that no discharge occurs between the grounded plate-like target electrode 2. To become
The continuous filament group 2 cannot be brought into close contact with the flat target electrode 7, which is not preferable.

Further, even if no voltage is applied to the guide plate 8,
By merely placing the guide plate 8 close to the continuous filament group 2 without contacting it, the flow velocity between the continuous filament group 7 and the guide plate 8 separated from the flat target electrode 7 together with the air flow is maintained at a high speed. Result continuous filament group 7
The continuous filament group 2 is drawn toward the guide plate 8 by the pressure difference obtained at the boundary. Therefore,
This method of drawing the continuous filament group 2 without applying a voltage to the guide plate 8 may be used. The material of the guide plate 8 used in the present invention may be any material having electrical conductivity when applying a voltage, and is not particularly limited when no voltage is applied to the guide plate 8.

Further, the shield plates 17 and 18 are provided between the high-speed airflow traction device 32 and the flat target electrode 7 and between the flat target plate 7 and the guide plate 8, and the continuous filament group 2 is transferred to the net conveyor 9. The shielding plates 17 and 18 are provided on the side opposite to the side on which they are deposited, and are divided into small pieces having a width of 20 to 50 mm. The shielding plates 17 and 18 are
Only between the high-speed airflow traction device 32 and the flat target electrode 7, or between the flat target electrode 7 and the guide plate 8
May be provided only between. Also, the individual shielding plates 17, 1
Reference numeral 8 is connected to moving devices 19 and 20, respectively, and the shielding plates 17 and 18 are movable forward and backward. The moving devices 19 and 20 are not particularly limited as long as they are reciprocating devices using a known stepping motor, induction motor, or the like, or devices that can move back and forth using an air cylinder or the like. In addition, shielding plates 17 and 18 are provided at arbitrary positions.
It is desirable that the device be capable of stopping the operation.
Note that a manual moving device using a handle and a screw may be used without installing the moving devices (driving devices) 19 and 20 by power.

FIG. 3 shows a shield plate 17 using a motor.
Of a moving device (drive device) that reciprocates the back and forth 18
It is sectional drawing which shows an example. The shield plates 17 and 18 are fixed to the shaft 23 with bolts. The shaft 23 is formed into a spline shaft in the middle and a moving screw 24 is cut at the tip. The spline shaft portion of the shaft 23 is fitted to the spline boss 28 fixed to the housing 29 of the moving devices 19 and 20, and the moving direction of the shaft 23 is defined and the shaft 23 slides. Further, the moving screw 24 of the shaft 23 is fitted with a female screw machined at the center of the worm wheel 25,
The shaft 23 moves by the rotation of the worm wheel 25, and the shielding plates 17, 18 also move at the same time. The worm wheel 25 meshes with the worm 26,
The worm 26 is connected to a drive motor (not shown) by a drive shaft 31 attached to the worm 26, and the rotation of the drive motor transmits the rotation in the order of motor → worm 26 → worm wheel 25 → moving screw 24. .
The position of the worm wheel 25 is fixed by a thrust bearing 27. As a method for connecting the drive motor (not shown) and the drive shaft 31, a method such as a direct connection structure using a shaft joint or a belt hook is used. Also, instead of the worm gears 25 and 26, a reduction gear using a spur gear,
You may use the reduction gear by a planetary gear.

The continuous filament group 2 ejected from the high-speed airflow traction device 32 collides with the flat target electrode 7 and flows along the guide plate 8 to be deposited on the net conveyor 9. The air blows out between the high-speed airflow traction device 32 and the flat target electrode 7. When the blowing air is blocked by the shielding plate 17, the accompanying air flows into the continuous filament group 2 side and acts to push the continuous filament group laterally. That is, when only the shielding plate 17 at the position where the density of the continuous filament group 2 is high is pressed against the high-speed airflow traction device 32, the density of the continuous filament group 2 decreases, and the density of the continuous filament group 2 deposited on the net conveyor 9 also increases. As a result, the weight of the nonwoven fabric web 10 in that portion is reduced.

When the shielding plate 18 is not provided, the continuous filament group 2 is located between the flat target electrode 7 and the guide plate 8.
When the divided shielding plate 18 is partially approached to the flat target electrode 7 side to block the inflow air, the continuous filament group 2 is in a negative pressure state because the inflow air is reduced, and And the density increases. Therefore, the density of the continuous filament group 2 in the portion where the shielding plate 18 is brought close is increased, and as a result, the basis weight of the nonwoven fabric web 10 deposited on the net conveyor 9 is increased.

That is, when the shielding plate 17 is partially approached, the unit weight of the portion is lowered, and when the shielding plate 18 is approached, the unit weight of the portion is increased. By controlling the movement of the shielding plates 17 and 18, the basis weight of the nonwoven fabric 12 can be adjusted. The weight of the nonwoven fabric 12 thermally bonded by the hot embossing roll 11 is measured by the basis weight measuring device 14 over the entire width of the nonwoven fabric 12. The basis weight of the nonwoven fabric 12 can be image-processed by the computer 15 and displayed on the monitor 21. The calculation is performed by the computer 15, and if there is a place above the reference weight, the drive unit 19 is operated via the controller 16 to move the shielding plate 17 to partially lower the basis weight of the nonwoven fabric 12. If there is a place below the reference basis weight, the drive unit 20 is operated via the controller 16 to move the shielding plate 18, and the basis weight of the nonwoven fabric 12 is partially raised. By continuously measuring the basis weight of the nonwoven fabric 12 with the basis weight measuring device 14 over the entire width, the shielding plates 17 and 18 are automatically moved via the computer 15, the controller 16 and the driving devices 19 and 20, and the basis weight of the nonwoven fabric 12 is automatically measured. Can be adjusted to the reference basis weight.

The shield plate 17 (a shield plate for adjusting the gap between the high-speed airflow traction device and the flat target electrode) and the shield plate 18 (a shield plate for adjusting the gap between the flat target electrode and the guide plate) are both provided. It is easier to adjust the basis weight if it is installed, but the basis weight can be adjusted with only one of them.

According to the present invention, a continuous filament group obtained by melt-spinning a thermoplastic resin from a spinneret into a cross-like shape is drawn and thinned by a high-speed airflow drawing device having a rectangular cross section, and is deposited on a net conveyor. In obtaining a non-woven web, the opening was improved by providing a corona discharge electrode, a flat target electrode, and a guide plate as a spreading device below the high-speed airflow traction device, and was divided into small pieces for adjusting the filament density. By providing the movable shielding plate, the filament density in the width direction of the nonwoven fabric is made uniform and deposited on the net conveyor, so that a nonwoven fabric having a uniform basis weight distribution and excellent formation can be obtained.

[0031]

【Example】

Example 1 Using the apparatus shown in FIG. 1, a polypropylene having a melt flow rate of 52 was melted at 230 ° C. and a rectangular spinneret (2,000 spinning holes, 10 rows, 1 row, 200 holes).
Pieces, 1 row length 1000mm, hole diameter 0.4mm) to 1
Melt spinning was performed at a discharge rate of 1 g per minute per hole, and the continuous filament group 2 was introduced into a high-speed airflow traction device 32 disposed below the spinneret, and was drawn and solidified at a speed of 4000 m / min. Below the high-speed airflow traction device 32, a corona discharge electrode (needle electrode) 5 having a needle density of 4 / cm ² connected to a DC high voltage power supply, and a flat target electrode 7 made of SUS304 grounded, A corona discharge unit having an interelectrode distance of 18 mm was arranged at an angle of 45 degrees, a corona discharge voltage of −18 KV was applied between the two electrodes to open the continuous filament group 2, and a direct current high voltage was applied below the corona discharge unit. A SUS304 guide plate 8 connected to a power supply was installed so as not to contact the continuous filament group 2, and a voltage of +8 KV was applied to the guide plate 8.

Further, the shielding plates 17 and 18 and their moving devices are connected between the high-speed airflow traction device 32 and the flat target electrode 7 and between the flat target electrode 7 and the guide plate 8 by the continuous filament group 2. Are provided on the side opposite to the side on which they are deposited on the net conveyor 9, and the shielding plates 17 and 18 are divided into 50 mm widths, and each of them is provided with 26 sheets. With this apparatus, a continuous filament group of about 2 denier was obtained. In addition, the basis weight 30g / m which was thermally bonded with a hot embossing roll
Continuously measure the basis weight of the nonwoven fabric of item ² with a basis weight measuring device using radiation (manufactured by Yokogawa Engineering Services Co., Ltd.), and use the measurement results to identify places with high or low basis weight in the width direction of the nonwoven fabric. , The shielding plates 17 and 18 below the high-speed airflow traction device 32 were automatically moved to adjust the basis weight.

Example 2 A nonwoven fabric was manufactured in the same manner as in Example 1 except that the voltage of the guide plate was set to 0 KV. Example 3 A nonwoven fabric was manufactured in the same manner as in Example 1 except that the interlock between the basis weight measuring device and the movement of the shielding plate was released, and the shielding plate was manually adjusted with reference to the data of the basis weight measuring device. Example 4 The interlock between the movement of the basis weight measuring device and the shielding plate was released, and the shielding plate 19 for adjusting the gap between the high-speed airflow traction device and the flat target electrode was removed, and shielding was performed with reference to the data of the basis weight measuring device. A nonwoven fabric was manufactured in the same manner as in Example 1 except that only the plate 20 was manually adjusted. Fifth Embodiment Shielding plate 2 for canceling the interlocking of the basis weight measuring device and the movement of the shielding plate, and adjusting the gap between the flat target electrode and the guide plate.
0 was removed, and only the shielding plate 19 was manually adjusted with reference to the data of the basis weight measuring device.

Comparative Example 1 A nonwoven fabric was manufactured in the same manner as in Example 1 except that the guide plate was not provided and the lower stage of the two stages of the shield plate was removed. Comparative Example 2 A nonwoven fabric was manufactured in the same manner as in Example 1 except that the guide plate was set so as to be in contact with the continuous filament group. Comparative Example 3 A nonwoven fabric was manufactured in the same manner as in Example 1, except that the interlock between the basis weight measuring device and the movement of the shielding plate was released, and the shielding plate was separated from the device and released.

The opened state of the nonwoven fabrics obtained in the examples and comparative examples was visually observed. Further, the obtained non-woven fabric is
After removing each 0 mm, it was cut to a length of 25 mm in the width direction and 500 mm in the flow direction, the individual weight was measured, the average value and the standard deviation were obtained, and the standard deviation / average value was obtained as the CV value (%). × 100. Table 1 shows the spread state and CV values of these obtained nonwoven fabrics.

[0036]

[Table 1]

As apparent from the above results, Example 1
In the nonwoven fabrics obtained in Steps 2 and 3, a state in which several tens of filaments were bundled was hardly observed, and a uniform and high-quality nonwoven fabric with a very open state was obtained without any unevenness. The nonwoven fabrics obtained in Examples 4 and 5 were also high quality nonwoven fabrics similar to these. On the other hand, in Comparative Examples 1 and 2, a part of the charge of the charged continuous filament group was removed by the charged and expanded continuous filament group coming into contact with the flat target electrode and the guide plate again, and the bundle of filaments was removed. It was present everywhere and a uniform nonwoven fabric could not be obtained.
Comparative Example 3 was a nonwoven fabric in which the spread state was good, but there was uneven weight and was inferior to those of the examples.

[0038]

According to the present invention, a continuous filament group which is conveyed with an air flow in producing a nonwoven fabric when a continuous filament group obtained by melt-spinning and bundling a thermoplastic resin is thinned and expanded by a high-speed airflow drawing device to produce a nonwoven fabric. Guide the group through a corona discharge electric field consisting of a corona discharge electrode and a plate-shaped target electrode, and carry a charge opposite to the charged charge of the continuous filament group without contacting the continuous filament group below the plate-shaped target electrode By installing the plate, the continuous filament group can be more closely adhered to the flat target electrode. In this state, the filament is passed through the corona discharge electric field and spread, so that the obtained nonwoven fabric is uniform.

Further, a small divided shield plate is installed between the high-speed airflow traction device and the flat plate target electrode and between the flat plate target electrode and the guide plate, so that a portion with a relatively large basis weight or By partially moving the shielding plate corresponding to a portion having a small basis weight and partially adjusting the amount of air entering and exiting the device, the basis weight of the nonwoven fabric can be adjusted in the width direction. In addition, the basis weight of the nonwoven fabric can be continuously measured in the width direction of the nonwoven fabric by the basis weight measuring device, and the shielding plate corresponding to a portion where the basis weight varies may be automatically moved to adjust the basis weight. The spunbonded nonwoven fabric having a uniform basis weight distribution can be obtained in a short time without any need for manual operation, as it can cope with not only distortion in the production of the rectangular cross section but also contamination and heat distortion of the rectangular cross section due to operation.

[0040]

[Brief description of the drawings]

FIG. 1 is a side view schematically showing an example of an apparatus used for a method for producing a spunbonded nonwoven fabric of the present invention.

FIG. 2 is an enlarged view of a lower portion of a high-speed airflow traction device used in the method for producing a spunbonded nonwoven fabric of the present invention.

FIG. 3 is a cross-sectional view illustrating an example of a moving device (drive device).

[Explanation of symbols]

 1: Spinneret 2: Continuous filament group 3: Ejector 4: Air channel 5: Corona discharge electrode (needle electrode) 6: Corona discharge high voltage power supply 7: Flat target electrode 8: Guide plate 9: Net conveyor 10: Non-woven web 11: Hot embossing roll 12: Non-woven fabric 13: Winding machine 14: Weight unit 15: Computer 16: Controller 17: Shielding plate 18: Shielding plate 19: Moving device (driving device) 20: Moving device (driving device) 21) Monitor 22: Non-woven fabric take-up roll 23: Shaft 24: Shield moving screw 25: Worm wheel 26: Worm 27: Thrust bearing 28: Spline (spline boss) 29: Housing 30: Oil seal 31: Drive shaft 32: High-speed airflow traction device

Claims (3)

[Claims] 1. A high-speed airflow traction device having a rectangular cross section, which is drawn and conveyed together with an airflow from a high-speed airflow traction device in order to narrow and stretch a continuous filament group obtained by melt-spinning a thermoplastic resin from a spinneret into an interdigital shape. In a method for producing a spunbonded nonwoven fabric, in which a set of interdigital continuous filaments to be guided to a corona discharge unit including a corona discharge electrode and a flat target electrode and spread the fibers, the continuous filament group is contacted below the flat target electrode. The guide plate is provided substantially in parallel with the plate-like target electrode at a position where the plate-like target electrode is not provided, and is provided in the gap between the high-speed airflow traction device and the plate-like target electrode and / or the gap between the plate-like target electrode and the guide plate in the width direction of the device. A shielding plate which is divided into small parts, and a device for individually moving the shielding plate, and the gap is partially changed by the movement of the shielding plate. A method for producing a spunbonded nonwoven fabric, comprising adjusting the basis weight by moving. 2. The apparatus according to claim 1, further comprising a device capable of continuously measuring the basis weight of the nonwoven fabric in the width direction, wherein the shielding plate is movable in conjunction with a signal from the device to adjust the basis weight. Production method of spunbond nonwoven fabric. 3. A continuous high-speed air-flow traction device having a rectangular cross section is drawn by a high-speed air-flow traction device to condense and draw a continuous filament group obtained by intermelting and spinning a thermoplastic resin from a spinneret. In the apparatus for manufacturing a spunbonded nonwoven fabric that guides the interdigitated continuous filament group to a corona discharge unit including a corona discharge electrode and a flat target electrode, at a position below the flat target electrode that does not contact the continuous filament group, The guide plate is provided substantially parallel to the flat target electrode, and is divided into small portions in the width direction of the device into a gap between the high-speed airflow traction device and the flat target electrode and / or a gap between the flat target electrode and the guide plate. Equipped with a shielding plate and a device for individually moving the shielding plate, and the gap can be partially adjusted by moving the shielding plate. An opening device for a group of filaments.