JPS6324106B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for widening and adjusting the width of a group of differentially charged filaments that are conveyed with an accompanying air flow, in which a charged object is provided in the air flow and the path of the filament group, and the width of the group of filaments is widened. The present invention relates to a novel method of regulation. Conventionally, the technology of charging a group of filaments and opening and widening the filaments by electrical repulsion between the filaments was disclosed in Japanese Patent Publication No. 37-4993, and it became the basic technology for obtaining filament nonwoven fabrics and has been used in various applications. Techniques are also shown. Among these applied techniques, the present inventors have found that a method of colliding a charged filament with an object to spread and disperse it is
Focusing on its industrial usefulness, we have been proceeding with studies. However, even if the material of the collision plate shown in JP-A No. 56-101938 is made of a metal mainly composed of copper or zinc, in the conventional technology, the charge held by the thread is taken away by the collision plate. . Another disadvantage is that when a large number of filaments run on the collision plate, they tend to form a lump or stick together. Furthermore, during long-term operation, the collision plate surface changes due to the collision of the filament, resulting in a disadvantage that it becomes unstable. As a result of extensive research, the inventors of the present invention found that in adjusting the width of a group of pre-charged filaments that are conveyed together with an accompanying air flow, a charged object is provided in the path of the air flow and the group of filaments. It has been found that the drawbacks can be overcome by adjusting the width. The charged object referred to in the present invention refers to a planar or curved plate-like body that allows airflow and filaments to pass through but not to reflect or slide, and a net-like body that allows only airflow to pass through and reflects or slides while not allowing filaments to pass through. means something that is electrically charged. Furthermore, the width adjustment referred to in the present invention means changing the width of the deposited web. In other words, this essentially means expanding the width of the filament group, which in turn increases the distance between the filaments, which also contributes to quality improvement. The filament group referred to in the present invention may be composed of either organic or inorganic fibers, and the fibers must be transported with an air flow and charged in advance. The transportation method is not particularly limited and may be a method using the propulsion force of an air flow, a method using the propulsion force of the fiber itself, or a combination thereof. Furthermore, any method may be used to charge the object, such as bringing it into contact with an object and charging it by friction, applying a conductive liquid and charging it with dynamic electricity, or running it near a high voltage electrode to electrostatically charge it. This can be done by charging by induction, or by moving through a corona discharge region to adsorb ions and charging. Regarding the position and angle of the charged object and the sliding distance on the reflective plate as a charged object in the present invention, the width of the web (width of a group of filaments) after approaching the charged object, for example, the width of the web (width of a group of filaments), It may be arbitrarily determined according to the expected web width when collected. For example, if the accompanying air flow is approximately 15N
When the amount of charge is less than m ³ /Hr, the charged object is placed approximately 10 to 100 mm below the charging device, and the angle is between 0 degrees (vertical direction) and 60 degrees to prevent the fiber from being charged. The sliding distance on objects is 5~
It is taken around 30mm. If the accompanying air flow is larger than that, the charged object is moved away from the charging device or the gliding distance is increased. When using a reflector as a charged object, a hard conductive material such as metal or ceramic should be used. The shape of the reflecting plate may be a flat plate or may have a curvature. The surface roughness may also be set arbitrarily. The shape of the reflector may be freely selected, such as a square or a semicircle. On the other hand, when a net-like material is used as the charged object, examples thereof include a wire mesh or a similar conductive net-like material. Regarding the position and angle of the charged object and the sliding distance on the charged object, the web width (width of the filament group) after approaching the charged object, for example, the expected width when collected on a moving net conveyor. It may be arbitrarily determined according to the web width. When using a charged object, there is a large air flow accompanying the filament group, e.g. 15Nm ³ /Hr.
It is very effective in the above cases. The wire diameter and mesh opening of the wire mesh constituting the collision object may be arbitrarily set depending on the expected width of the filament, as described above. For example, about 25-30N
In the case of an associated air flow of m ³ /Hr, it is taken around 300 meshes. The method for charging the charged object in the present invention is a conventional method. That is, this is done by connecting to a DC high voltage power source. The sign of the power supply voltage at this time may be arbitrarily selected depending on the material composing the filament group, and the voltage is approximately 10 to 30KV.
taken to a certain extent. The voltage is adjusted depending on the width of the filament group or the running condition. Next, a more detailed explanation will be given with reference to the drawings. FIG. 1 is a schematic diagram showing one example of a preferred embodiment of the present invention. The filament group 2 discharged from the spinneret 1 is stretched and ejected by an air sucker 3, and is charged by friction with a frictional charging plate 4. Next, a DC high voltage power source 6 applies a charged voltage to a reflecting plate 5, which is an example of a charged object placed in the path of the filament group. Since the filaments are pre-charged, if no voltage is applied to the reflector, the potential of the reflector is low and they will be electrostatically attracted and lose their charge, or if there are a large number of filaments, the reflector will lose its charge. It may stick. On the other hand, when a voltage is applied, the repulsive force of static electricity of the same sign not only causes the filaments to float above the reflector, but also changes the width of the filaments as they are emitted into the air, increasing the amount of charge on the filaments and increasing the voltage. If so, the width becomes large. The filament group whose width is adjusted in this way by the charged voltage of the reflection plate is deposited on the net conveyor 7 to form the web 8. FIG. 2 is also a schematic diagram showing one example of a preferred embodiment of the present invention. A group of filaments 9 sent at a constant speed by a nip roll 10 is taken up by an air sucker 3, and the ejected group of filaments is passed through a needle electrode 12 connected to a DC high voltage power source 6 and a grounded flat target electrode 11. A reflecting plate 5 is introduced into the corona discharge unit configured to adsorb and charge ions on the thread, and is further charged with the same sign as the thread connected to a DC high voltage power source 6'.
After running on the web, the web 8 is deposited on a similarly moving net conveyor 7. According to the present invention, the width of the filament group can be adjusted arbitrarily by providing a charged object in the path and changing the charging voltage of the charged object to allow the filament group to be conveyed together with the accompanying air flow that has been charged in advance. The width can be adjusted to increase the width, and it is highly controllable. Examples and comparative examples will be explained below. In the examples, the amount of charge was measured using a charge meter (model KQ-431B, manufactured by Kasuga Electric). Comparative Example 1, Examples 1 to 4 A group of 68 untwisted polyester filaments each having a single yarn of 1.5 denier was pulled by a roll at a speed of 1000 m/min and taken up by an air sucker. At this time, the flow rate was about 10Nm ³ /Hr, and the pressure was 0.7Kg/cm ² G. A corona discharge unit was installed 5 mm below the air suction unit, and the unit consisted of 10 needle electrodes arranged vertically at a 2.5 mm pitch and an 86 mm square SUS target electrode with a distance of 15 mm between the electrodes. A negative voltage was applied. A 50 x 150 mm reflective plate made of copper was installed at a 45 degree angle 40 mm below the corona discharge unit so that the sliding distance of the filament group was approximately 20 mm, and a negative voltage was applied to the plate. Furthermore, it was collected on a moving net conveyor 50 cm below and made into a web. The results are shown in the table.

【table】

[Table] The amount of charge held by the web in Comparative Example 1 is
3.8μc/g in Examples 3 and 4, respectively
They were 4.7 μc/g and 5.3 μc/g. That is, it will be understood that the web width can be adjusted by charging the reflecting plate, and the amount of charge is also large. Example 5 Nylon 6 was discharged from a spindle having 46 holes by the method shown in Fig. 1, and was placed about 1 m below the spindle.
Air suction car at position (pressure 3Kg/cm ² G flow rate 20N)
m ³ /Hr) to obtain a filament group having a single filament denier of 1.5 denier. A chrome-plated frictionally charged plate (angle 25 degrees, sliding distance 60mm) was set approximately 10mm below the air carrier to create a frictional charge. Furthermore, a 300-mesh SUS wire mesh was placed 10 mm in front of the plate as a material for the charged object, and placed so that the filament group would fall along it in the vertical direction so that the sliding distance would be approximately 10 mm. A high positive voltage was applied. The filament group is separated from the accompanying air flow, and is opened well, approximately 3 cm larger than when no voltage is applied.
Web width has been expanded.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, and FIG. 2 is a schematic diagram showing another embodiment of the present invention. 1... Spinneret, 2... Filament group, 3... Air sucker, 4... Frictionally charged plate, 5... Reflector, 6, 6'...
DC high voltage power supply, 7...Net conveyor, 8...Web, 9...Filament group, 10...Nipprol,
11... Target electrode, 12... Needle electrode.

Claims (1)

[Claims] 1. A filament characterized in that when adjusting the width of a group of pre-charged filaments conveyed with an accompanying air flow, a charged object is placed in the path of the air flow and the group of filaments. How to adjust group width. 2. A method as claimed in claim 1, in which the filaments are fed at a constant speed to an air sucker, which transports the filaments together with an accompanying air flow. 3. The method according to claim 1, wherein the charged object is a plate-shaped object. 4. The method according to claim 1, wherein the charged object has the ability to separate the airflow from a filament through which a portion of the airflow can pass. 5. The method according to claim 1, wherein the width of the filament group is adjusted by changing the charging voltage of the charged object.