JPH08246319A - Production unit for spunbonded nonwoven fabric - Google Patents

Abstract

PURPOSE: To obtain a spunbonded nonwoven fabric uniform in basis weight distribution and excellent in formation. CONSTITUTION: A group of continuous filaments made by melt spinning, screen- fashion, of a thermoplastic resin from a spinneret is drafted and oriented by a high-speed air jet drafting device 3 with rectangular section. A filament density regulator 4 is set up under the drafting device 3 and equipped with a number of air jet nozzles. For the regulator 4, both air jet pressure and nozzle diameter are controlled to effect uniformizing the filament density in the width direction and the resultant filaments are accumulated on a net conveyer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for continuously producing spunbonded nonwoven fabric composed of continuous filaments. More specifically, the present invention relates to an apparatus for producing a spunbonded non-woven fabric having a uniform basis weight distribution.

[0002]

2. Description of the Related Art A spunbonded nonwoven fabric is obtained by melt-spinning a thermoplastic resin into a continuous filament group, which is thinned and stretched by using a high-speed airflow traction device to change the distribution density of the continuous filament group inside and outside the high-speed airflow traction device. In recent years, the demand has been increasing as a method for obtaining a nonwoven fabric at low cost by a method of forming a nonwoven web by depositing it on a net conveyor after making it uniform. It is becoming important to obtain a technique for making the uniform distribution and the uniform areal distribution.

Various methods have been proposed for making the distribution density of continuous filaments uniform, but a continuous filament group melt-spun in a comb shape from a rectangular spinneret in which spinning holes are arranged in a rectangular shape is used as a traction path. Is used as a method for obtaining a wide nonwoven fabric having no streaks by using a high-speed airflow traction device having a narrow rectangular cross section and a wide rectangular cross section. In this case, the continuous filaments are arranged in a comb shape in the width direction by the spinneret and the high-speed airflow traction device having the almost same width of the finally obtained nonwoven product, but it is hard to say that they are uniformly dispersed. A number of opening methods have been proposed for evenly dispersing. This opening method is a method of diffusing an air flow accompanying a continuous filament group ejected from a high-speed air flow traction device and multiplying the diffusion of the air flow to disperse it, and applying a homopolar charge to the continuous filament group by frictional charging and corona discharge. Many methods have been proposed, such as a method of applying and opening the fibers by the repulsive force thereof, a method of swinging the continuous filament group at the jet outlet to widen the dispersion width, and the like.

In any of these methods, the constituent fibers of the continuous filament group can be sufficiently dispersed individually, and the arrangement of the fibers in the local portion is disordered, but the obtained product is When looking over the whole area, it was difficult to suppress the unevenness of the weight.

That is, in the case of using a high-speed airflow traction device having a narrow rectangular cross-section and a wide rectangular cross-section, a high technique is required to uniformly inject the continuous filaments introduced in a comb shape with the high-speed airflow in the width direction. It will cost. For this purpose, it is necessary to finish the inside of the high-speed airflow traction device, in particular, the shape of the injection port with high accuracy, but this requires a high technique for finishing and also increases equipment costs and maintenance costs.

Therefore, in order to suppress the occurrence of non-uniform weight, the width of the cross-sectional shape of the injection port is divided into several numbers in the width direction of the high-speed airflow traction device, and the width of the cross-sectional shape can be adjusted independently. Therefore, a method of making the density of the continuous filament group uniform has been proposed. (JP-A-52-59
However, this method has a problem that processing and maintenance of the high-speed airflow traction device still require labor and time, and adjustment requires skill.

[0007]

SUMMARY OF THE INVENTION In the present invention, the problem of the known technique is solved in order to suppress the occurrence of unevenness of basis weight, and the basis weight of a continuous filament group can be obtained by a simple operation without labor and processing of equipment. It is an object of the present invention to provide a facility for manufacturing a spunbonded nonwoven fabric capable of suppressing unevenness and having a uniform basis weight distribution.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a continuous filament group in which a thermoplastic resin is melt-spun in a comb shape from a spinneret is drawn by a high-speed airflow traction device having a rectangular cross section to be thinly drawn and moved. When manufacturing a non-woven web by depositing on a conveyor, a filament density adjusting device that has a large number of air injection nozzles in the width direction below the high-speed airflow traction device and is capable of finely adjusting air pressure and nozzle hole diameter independently The apparatus for producing a spunbonded nonwoven fabric having a uniform basis weight distribution, which is characterized in that the filament density in the width direction is made uniform by being provided and the filaments are deposited on the net conveyor.

An apparatus for producing a spunbonded nonwoven fabric equipped with the filament density adjusting apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of a spunbonded nonwoven fabric manufacturing facility equipped with the filament density adjusting apparatus of the present invention. In FIG. 1, the spinneret 1 has spinning holes arranged in a straight line,
The spinning filaments arranged in a plurality of rows are shown, and the melt-spun continuous filament group 2 is guided to the high-speed airflow traction device 3 in the form of a comb, and is thinned and drawn between the spinneret 1 and the high-speed airflow traction device 3. . Below the high-speed airflow traction device 3, there are filament density adjusting devices 4 composed of a large number of finely adjustable pressure adjusting valves 7 and air injection nozzle holes 9 in the width direction on both sides of the filament group, and the filament density adjusting devices are connected continuously. As the filament group passes, the density of the filament group is adjusted, and the filament web is deposited on the net conveyor 5 moving at a constant speed to form the nonwoven web 6.

FIG. 2 is a view showing an example of the arrangement of the air injection nozzle holes 9 and the pressure adjusting valve 7 of the filament density adjusting device of FIG. The continuous filament group 2 passes between the filament density adjusting devices.

FIG. 3 is a schematic view showing the flow of a continuous filament group ejected from one side of the filament density adjusting device and the high-speed airflow traction device. FIG. 3 shows a state in which an air flow is ejected from the nozzle 9 of the filament density adjusting device to a place where the filament density of the continuous filament group 2 ejected in a comb shape is large. By applying an air flow to a place where the filament density is high, the filaments are dispersed and the filament density becomes uniform. Moreover, a plurality of nozzles from which the air flow is ejected are arranged in the width direction,
It is possible to adjust the filament density over the width direction.

4 and 5 are views showing the state of the throttle of the air injection nozzle hole. FIG. 4 shows a state in which the aperture is closed and the nozzle hole is slightly opened, and FIG. 5 is a state in which the aperture is opened and the nozzle hole is wide open. The air injection nozzle of FIG. 4 injects a pressure-adjusted air flow from the air injection nozzle hole 9.
Further, the aperture 11 can be adjusted by rotating the air injection nozzle like adjusting the aperture of the camera, and the diameter of the air injection nozzle can be freely adjusted. As shown in FIGS. 4 and 5, the change of the diaphragm is shown in FIG. 4 in a state in which the diaphragm is largely closed, and in FIG. 5 in a state in which the diaphragm is slightly opened as compared with FIG. Therefore, in FIG. 5, the diameter of the air injection nozzle is increased by adjusting the aperture as compared with FIG. 4, and a larger amount of air flow can be injected.

The spinneret used in the present invention has a width of 500 mm to
Several rows (5-10 rows) within a rectangular shape of about 3000 mm
It is desirable to use one in which a large number (100 to 600) of spinning holes are arranged in the width direction, and the thermoplastic resin used is not particularly limited as long as it has a fiber morphology. Resins such as polypropylene, polyethylene terephthalate, polyethylene, and nylon, or mixtures and copolymers thereof can be used.

As shown in FIG. 1, the high-speed air-flow traction device 3 has a property as a continuous filament that constitutes a nonwoven fabric by sufficiently stretching and solidifying the continuous filament group 2 melt-spun from the spinneret 1 below the spinneret 1. Should be separated from each other. The distance between the plurality of air injection nozzles arranged in the filament density adjusting device of the present invention is 30 to 150 mm.
The degree is preferred. If the distance between the air injection nozzles exceeds 150 mm, it is difficult to completely adjust where the filament density is very high. If it is less than 30 mm, it is not necessary because it can be sufficiently adjusted with one nozzle hole. Further, the filament density adjusting device may be used only on one side of the filament group, but when it is used on both sides, it is preferable that the air injection nozzle hole positions are staggered as shown in FIG. This is because it is difficult to adjust when there is a portion with a high filament density between the air injection nozzle hole and the nozzle hole when using the filament density adjusting device on only one side, so use the filament density adjusting device on the other side as well. By staggering the nozzle holes of the filament density adjusting device, the filament density can be made more uniform.

As a device for adjusting the air pressure of the filament density adjusting device of the present invention, a pressure adjusting valve or the like can be used, and it is not particularly limited as long as it can be adjusted appropriately. Also, the air pressure is preferably 1 to 5 kg / cm ² ,
The air pressure of each nozzle may be adjusted depending on the density of the filament group ejected from the high-speed airflow traction device. The air injection nozzle hole has only to have a function capable of adjusting the throttle, and a commonly used needle valve can be used. There is no particular limitation as long as the nozzle hole diameter can be freely adjusted as shown in FIGS. 4 and 5 by adjusting the diaphragm like the diaphragm of the camera lens. The shape of the nozzle hole may be circular, elliptical, polygonal or the like and is not particularly limited as long as the filament density can be adjusted. Therefore, by using the air pressure and the throttle of the nozzle hole together, it is possible to adjust by increasing the air pressure and increasing the nozzle hole diameter where filament density is very high.
On the contrary, when the filament density is slightly high, the adjustment can be performed under all conditions by adjusting the air pressure to reduce the nozzle hole diameter.

As shown in FIG. 1, the filament density adjusting device used in the present invention is installed directly under the high-speed airflow traction device, and is arranged on one side or both sides of a continuous filament group ejected together with the high-speed airflow. If you have. Therefore, in the spunbonded nonwoven fabric manufacturing apparatus of the present invention equipped with a filament density adjusting device, the distribution density of the continuous filament group in the width direction is measured, and individual air pressure and nozzle hole diameter are adjusted according to the density difference. A non-woven web is formed by being deposited on a net conveyor that moves at a constant speed so that the filament density in the width direction is uniformly adjusted and a desired basis weight is obtained.

[0017]

According to the present invention, a continuous filament group obtained by melt-spinning a thermoplastic resin in a comb shape from a spinneret is drawn by a high-speed air flow drawing device having a rectangular cross section to be thinned and drawn. When a nonwoven web is obtained by stacking, a filament density adjusting device is installed under the high-speed airflow traction device to make the filament density in the width direction uniform and deposit it on the net conveyor, resulting in a uniform basis weight distribution and excellent formation. Has the effect of obtaining a non-woven fabric.

[0018]

【Example】

Example 1 Polypropylene having a melt flow rate of 50 was melted at a melting temperature of 230 ° C. using a device shown in FIG. 1 to form a rectangular spinneret (2,000 spinning holes, 10 rows, and 200 rows per row).
The length of each row is 1000 mm, the hole diameter is 0.4 mm), the melt spinning is performed at a discharge rate of 1 g per minute per hole, and the continuous filament group is introduced by the high-speed air-flow traction device arranged below the spinneret. The filament was stretched and solidified at a speed of about 4000 m to obtain a continuous filament group of about 2 denier. The continuous filament group is ejected together with the high-speed airflow from the high-speed airflow traction device, and then the filament density adjusting device provided with 10 air injection nozzles provided below the high-speed airflow traction device at intervals of 100 mm sandwiches the continuous filament group and the filaments of each other. The air injection nozzle hole positions of the density adjusting device are staggered as shown in FIG. 2, and the air pressure and the nozzle hole diameter of each air injection nozzle are adjusted according to the filament density to 70
The spunbonded nonwoven fabric having a basis weight of 25 g / m ² was deposited on a net conveyor moving at a speed of m, and thereafter, the upper stage was hot-embossing rolls and the lower stage was a smooth roll by a partial thermocompression bonding apparatus.

Example 2 A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the filament density adjusting device was used on only one side. Example 3 A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that an air jet nozzle having a constant nozzle hole diameter of 5 mm and a circular hole shape was used.

Comparative Example 1 A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the filament density adjusting device was removed. Comparative Example 2 The air injection nozzle interval of the filament density adjusting device was set to 20.
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the thickness was 0 mm. The spunbond obtained after removing the ears by 50 mm each has a width of 25 mm in the lateral direction and 500 mm in the flow direction.
Cut into lengths, measure individual weights, calculate the average value and standard deviation, and calculate the CV (%) value as standard deviation / average value ×
It is indicated by 100.

[0021]

[Table 1]

As shown in Examples and Comparative Examples, the non-woven fabrics obtained by the spunbonded non-woven fabric manufacturing apparatus equipped with the filament density adjusting device of the present invention have a small CV (%) value. Became a uniform nonwoven fabric. On the other hand, a spunbonded non-woven fabric having a non-uniform basis weight distribution was obtained, as shown by a large CV (%) value when the filament density adjusting device was not provided or when the air injection nozzle interval was increased.

[0023]

Industrial Applicability The spunbonded nonwoven fabric manufacturing apparatus according to the present invention is provided with a rectangular cross-section high-speed airflow pulling device for thinning and stretching a continuous filament group obtained by melt-spinning a thermoplastic resin into a comb shape from a spinneret. Since a filament density adjusting device including an air injection nozzle group in which a large number of hole diameters can be adjusted at intervals in the width direction and an air pressure adjusting valve for individually adjusting the injection air pressure of each nozzle is provided. By injecting air into the thinned and stretched filament group and adjusting the pressure and flow rate of the air, the density of the filament group in the width direction can be adjusted and made uniform. Therefore, the apparatus of the present invention can produce a spunbonded non-woven fabric having a uniform basis weight distribution and a good texture.

[Brief description of drawings]

FIG. 1 is a side view schematically showing an apparatus for producing a spunbonded nonwoven fabric according to the present invention.

FIG. 2 is a plan view showing an arrangement of air injection nozzle holes and a pressure adjusting valve of the filament density adjusting device of the present invention.

FIG. 3 is an explanatory diagram showing a flow state of a continuous filament group when the filament density adjusting device of the present invention is used.

FIG. 4 is an explanatory view showing how the air injection nozzle of the filament density adjusting device of the present invention is throttled.

FIG. 5 is an explanatory view showing how the air injection nozzle of the filament density adjusting device of the present invention is throttled.

[Explanation of symbols]

 1 Spinneret 2 Continuous Filament Group 3 High Speed Air Flow Traction Device 4 Filament Density Control Device 5 Net Conveyor 6 Nonwoven Web 7 Pressure Control Valve 8 Air Pipe 9 Air Injection Nozzle Hole 10 Air Injection Nozzle 11 Throttling

Claims (1)

[Claims] 1. A high-speed airflow traction apparatus for producing a spunbond nonwoven fabric, which comprises a high-speed airflow traction device having a rectangular cross section for thinning and stretching a continuous filament group in which a thermoplastic resin is melt-spun in a comb shape from a spinneret. Filament density consisting of a large number of air injection nozzle groups with adjustable hole diameters arranged at intervals in the width direction downstream of the device and an air pressure adjusting valve for individually adjusting the injection air pressure of each nozzle An apparatus for producing a spunbonded nonwoven fabric, which has an adjusting device.