JPS5947065B2 - Continuous filament feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a device that pulls and sends out continuous filaments spun from a spinneret using high-speed airflow, and is a device that completely disperses the filaments and creates an even web. .

In a nonwoven fabric production method called spunbond, in which a nonwoven web is made directly from continuous filaments spun from a melt-spinning nozzle, the filaments are pulled and fed through a narrow rectangular passage with high-speed air. A method is disclosed for forming a web on a moving collection device after subjecting the filament to the action of . However, there remains a problem in completely separating and dispersing the filaments. As one solution to this problem,
The method disclosed in Japanese Patent No. 7-4993 is a method of separating and dispersing filaments by electrostatically charging a traveling continuous filament. However, in the method shown here, static electricity is applied to the filament before it passes through the advancing device, so the filament, once uniformly charged, loses its charge and is recharged as it passes through the advancing device. The uniformity of charging is not lost, and a difference occurs in the repulsive force between the filaments. This not only causes the distribution of filaments to be uneven, but also causes the filaments to adhere to the advancing device in some cases, making it difficult to maintain a stable dispersion state. Here, in order to disperse the filaments in an average manner, a defective condition can be considered.

(b) In order to make the filament distribution uniform across the entire width of the web, an air sucker having a rectangular filament passage whose longitudinal dimension is approximately equal to the web width is used to create an even curtain of filaments. thing.

(Re) Immediately before the filament is discharged from the traction and feeding device, the filament is charged with an electrostatic charge. Under conditions e→ (O), the air flow is fast;
Therefore, it is difficult to apply electric charge by corona discharge, and it is necessary to apply electric charge to the filament by contact triboelectric charging.

The friction of the filament (→) should be done only at one point, and the filament should not be rubbed at any other part.

This invention satisfies the above conditions.

That is, in this invention, when a large number of continuous filaments are pulled and sent out using a rectangular air sucker having a narrow rectangular filament passage, a curtain in which the filaments are arranged in a line is provided at the exit of the passage. This delivery device is provided with an inclined plate extending from the lower end of one side of the inner wall of the passage at an angle receding with respect to the wall in order to contact the edge portion. As the filament moves along the inclined plate, it can obtain an equal amount of triboelectricity by contacting the edge portion. The invention will be explained with reference to figures.

The continuous filament 2 leaving the spinneret 1 enters a rectangular air sucker 3.

The sucker is fitted with a pressurized air supply pipe 4, the pressurized air enters the chamber 5 and is injected downwardly through the ejection slit 6 into the passage 7, the filament moving downwards with the high velocity air stream. And the angle of inclination θ that recedes with respect to one wall of the passage T
As the filament flows along the inclined plate 8 having a slanted surface, the filament is rubbed and charged at the edge of the end of the wall. The filaments are then dispersed by the electric charge and ejected onto the collection device 10, and the air stream is sucked into the suction device 11 to create the web 12. The flow of air is illustrated in FIG. 3. After passing through the passage 7, the pressurized air jetted downward from the slit 6 is refracted and flows along the inclined plate 8 due to the Coander effect. Along with this, the filament is also bent and passes through, and is rubbed and charged at the edge 9 formed by the passage T and the inclined plate 8. Although an edge portion is formed at the connection point between the inner wall and the inclined plate, the inner wall and the inclined plate may be integrated, or by providing a protrusion at the connection point between the inner wall and the inclined plate. An edge portion may also be formed. What is important here is that the filaments are aligned in a line and contact the edge portion, so that each filament has an equal amount of charge. Therefore, the gap α of the passage T is a problem, and the angle θ of the inclined plate due to friction.
It is necessary to consider the length t and the length t. Therefore, we conducted experiments by changing these conditions, which will be described below. Examples 1 to 15 Polycaprolactam chips with a relative viscosity of 2.3 (1Cf6 solution of 99% concentrated sulfuric acid) were spun at a spinning temperature of 265°C with a pore size of 0.
A continuous filament is formed by spinning from a 25 mm spinning nozzle, and the filament is pulled at a speed of 3,000 m/1 and sent onto a conveyor moving at a speed of 15 m/1 to produce a web with a fiber weight of 50 y per square meter. I made it.

For stainless steel air suckers, gauge pressure 2.
Caro pressure air of 5kg/CIIIG is applied to the slit gap of 0.1
The longitudinal dimension is 30 mm from the 5-inch pressurized air jet slit.
It is ejected at a flow rate of 4.3N/1 into a rectangular filament passageway with zero pressure. Table 1 shows the results of varying the filament passage gap α, the length t of the inclined plate, and the angle θ between the filament traveling direction and the inclined plate. The charge amount in the table is the charge voltage measured using a current collector potential measuring device on the web on the conveyor, and is in kilovolts.
Sampled from 30 locations with a length of 100 meters,
The weight of each sample is measured and the basis weight variation rate (.=maximum weight - minimum weight x 100) is obtained.

If the average weight variation rate of basis weight is less than 5%, it can be considered that the uniformity of filament distribution is excellent.

As is clear from the table, in order to obtain a web with excellent filament distribution uniformity and good filament dispersion, α=1 to 10 nm. It is desirable that t=10 to 100 degrees and θ=10 to 45 degrees. In the above embodiments, the case where one type of filament is spun is explained, but the present invention can also be used when two or more types of synthetic fibers are mixed and dispersed.

Example 16 When untwisted multifilament yarns of polyethylene terephthalate (100 denier/50 filaments) and untwisted multifilament yarns of polycaprolactam (100 denier/50 filaments) were introduced into the pulling and feeding device of Example 1, each The filaments were opened and a uniform mixed web could be obtained.

As a comparative example, the results are shown in the case where there is no inclined plate and in the case where the filament is charged by friction before entering the soccer ball.

Comparative Example 1 When a web with a fiber weight of 50y per square meter was produced in Example 1 except for the inclined plate, the amount of charge was 0.5.
kv, the basis weight variation rate was 21.2%, and the filament dispersion state was also poor.

Comparative Example 2 In Example 1, except for the inclined plate, the filament was brought into contact with a filament guide rod (25 mm x 25 mm square rod) made of chromic oxide (25 mm x 25 mm square rod) provided at a position 100 degrees above the air sucker to apply a triboelectric charge. So, 50V/Ri? I created a web for.

Although the amount of charge on the web was 19 kV, the area weight variation rate was 10.5%, and the filament dispersion state was not good. As explained above, according to the present invention, filaments are uniformly and completely dispersed, and a good web can be produced with high efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a detailed explanatory diagram of the present invention as seen from the direction in which the web travels, FIG. 2 is a sectional side view of the feeding device, and FIG. 3 is an explanatory diagram of the feeding device. 1... Spinneret, 2... Filament, 3... Rectangular sucker, 6... Pressurized air ejection slit, 7... Filament. aisle,
8... Inclined plate, 9... Edge portion, 10
...Filament collection device.

Claims (1)

[Claims] 1 Narrow rectangular filament passage (width d = 1 to 10
An inclined plate (length l = 10 to 45 mm) with an angle θ (10 to 45) with respect to the filament traveling direction downward and outward from the lower end of one side of the inner wall of the rectangular soccer
100mm) continuous filament delivery device.