JPH0159362B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a short fiber removal method and apparatus for removing short fibers from a group of fibers using static electricity. In addition, in the present invention, short fibers include
Refers to the fibers in the fiber group whose fiber length is calculated as short fiber content in the cotton fiber fiber length measurement method specified in JISL1019.

Conventional technology In the spinning process, in order to produce high-quality yarn, it is important to remove short fibers, which are usually present in a few percent or more in the raw material fiber group, and to make fiber bundles as parallel as possible. be. On the other hand, the most common method for removing short fibers currently in use is a mechanical method such as a pulling action or a combing action from fibers or fiber bundles held at one end such as in a comb. In addition to the mechanical methods mentioned above, a method using static electricity has been proposed [Textile World, June 1966 issue, (Textile Technology News No. 354, published by the Japan Textile Spinning Association, September 1966)]. has been done. That is,
This method uses an asymmetric electrostatic field, and its principle is as follows. As shown in FIG. 3, there are two electrodes, one of which 1 is formed in a planar shape, and the other one 2 is formed in a curved surface shape that is a part of an ellipse. These two electrode surfaces are arranged as shown in FIG. 3 above, and their potential changes non-linearly in inverse proportion to the distance between the electrodes. In actual operation, individual fibers are fed between the electrodes A at the point of lowest electrostatic field strength. Then, these fibers are arranged along the direction of the force between the electrodes, and the fibers are further attracted toward the point B where the electric field strength is strong. In this case, the long fibers F _l move more quickly to the point B than the short fibers Fs. The short fibers Fs are not as easily attracted to the above-mentioned point B where the electric field strength is strong as the long fibers _Fl , and remain in the point A where the electric field strength is weak for a long time. This principle allows fibers to be separated according to their length, and short fibers Fs can be removed between the electrodes. FIG. 4 shows an example of a specific device, which is equipped with a flat electrode 1 and a curved electrode 2 of the same type as shown in FIG. In order to carry out a certain continuous production, an endless belt 3 is arranged to traverse between the two electrodes 1, 2 and successively carry away the fibers from the supply side. This endless belt 3 moves the arranged fibers in a direction perpendicular to the direction of fiber transfer and movement. The long and short fibers are then conveyed to two separated suction ducts: a short fiber take-out duct 4 for taking out the short fibers _Fs , and a long fiber take-out duct 5 for taking out the long fibers Fl.

Problems to be Solved by the Invention Among the above-mentioned conventional methods for removing short fibers from a group of fibers, mechanical methods tend to cause fiber breakage, and at the same time the short fibers are removed, conversely. This results in the formation of short fibers and neps, making it extremely difficult to reduce the short fibers below a certain limit, and further causing problems such as an increase in the amount of short fibers to be removed. In addition, in the case of the electrostatic method, the short fibers remain in a place where the electric field strength is weak for a long time, and the short fibers floating between the electrodes aggregate and become connected in the form of long fibers. may move to
There are problems such as poor short fiber separation efficiency.

The present invention focuses on an electrostatic method for removing short fibers from a fiber group, and aims to provide a short fiber removal method and an apparatus therefor, which solves the problems of the conventional methods as described above. be.

Means for Solving the Problems In order to solve the above-mentioned problems, the short fiber removal method of the present invention applies high voltage static electricity between opposing meshes, and while suctioning from the back side of each mesh,
The apparatus for removing short fibers of the present invention is characterized in that a group of fibers is supplied between the meshes, the fibers are held substantially perpendicular to the surface of the mesh, and the short fibers are removed by suction. Two nets facing each other with a gap between them,
Consisting of a static electricity generator that applies high-voltage static electricity between the meshes, a suction device provided on the back side of the opposing meshes, and a fiber group supply device provided on the side between the opposing meshes. It is characterized by:

Function In the present invention, the short fiber removal device is configured to be able to apply high-voltage static electricity between two meshes facing each other at a predetermined interval by suction from the back side, and between the meshes. By supplying a group of fibers, the fibers are held almost perpendicular to the mesh surface between the meshes, and the fibers with long fiber length are continuous and form a bridge between the meshes, and are held as they are. but,
The short fibers reciprocate between the two meshes due to electrostatic attraction, and are eventually drawn to the back side by the suction air current and removed, making it possible to efficiently remove the short fibers without causing any damage to the fibers.

Embodiment An embodiment of the present invention will be described based on the drawings. FIG. 1 shows an outline of the apparatus of this embodiment. 11,12
is an endless net, and both the nets 11 and 12 have net surfaces 11a and 12a facing each other almost vertically in parallel with a predetermined interval (usually 1.5 to 2.5 times the effective fiber length of the fiber group); The surfaces 11a and 12a are provided so as to circulate downward by a drive device (not shown). Both mesh surfaces 11 facing each other
Suction devices 13 and 1 are provided on the back side of a and 12a, respectively.
4, a high-voltage static electricity generator 15 is connected to the net 11 side, and the net 12 side is grounded 16. Further, a fiber group supply device 17 is provided at the upper end between the opposing net surfaces 11a and 12a, and is supplied to the outside of the nets 11 and 12 from the intermediate portion of one of the left and right side edges to the lower part of the other side edge. A protruding inclined conveyor belt 18 is provided so that its upper surface can run downward on the slope, and a press belt 19 is disposed in contact with the upper surface of the conveyor belt 18. As the nets 11 and 12, a porous rubber sheet, a metal porous plate, a metal net, etc. are used.

In the above device, static electricity of high voltage (usually 30,000 to 50,000 volts) is applied between both the screen surfaces 11a and 12a, and the suction device 1 behind both the screen surfaces 11a and 12a
3 and 14 and drive both nets 11 and 12, conveyor belt 18, and press belt 19, if the fiber group is supplied from the fiber group supply device 17, the fibers will be distributed between the two net surfaces 11a and 12a. Due to electrostatic attraction and attractive force, the fibers are arranged almost perpendicularly to the mesh surfaces 11a and 12a, and the fibers, which are relatively long, are connected to each other and form a bridge between the mesh surfaces 11a and 12a. However, the short fibers float back and forth between the mesh surfaces 11a and 12a due to electrostatic force, and are sucked and removed from the meshes of the mesh surfaces 11a and 12a. The long fibers have both mesh surfaces 11a, 1
Both mesh surfaces 11a and 12 are held between 2a.
a, and move downward with the belt conveyor 1 at the bottom.
8 and held between the press belt 19 and conveyed to the outside to become a fiber group from which short fibers have been removed.

FIG. 2 shows both mesh surfaces 11a and 12 in FIG.
This shows another embodiment in place of the press belt 19 on the conveyor belt 18 provided between Suction device 2 is installed near the center of both longitudinal sides.
1 and 22 are installed opposite each other. When this device is used, the fibers held between the mesh surfaces 11a and 12a and captured on the conveyor belt 18 are gripped at the center by the press roller 20 and move forward, At point 22, the free end side of the fiber held by the narrow pressing belt 20 is suctioned, and the short fibers sandwiched between the long fibers are further suctioned and removed, and the net surface 11a, 1
The fiber ends that have been bent due to contact with 2a are stretched by the suction force and become straight, resulting in good fiber alignment.

Effects of the Invention In the present invention, a plurality of long fibers in a fiber group are held in a continuous, bridge-like manner between opposing meshes, approximately perpendicular to the mesh surface, and the ends of the fibers are in point contact with the mesh surface. There is no possibility that the mesh will become clogged, and there is very little chance of it being sucked through the mesh. On the other hand, since the short fibers have a short fiber length, they float back and forth between the two mesh surfaces due to electrostatic attraction, and are removed from the mesh by the suction airflow without being continuous in a bridging manner. That is, short fibers can be removed extremely efficiently due to the synergistic effect of applying electrostatic attraction and suction between the opposing meshes. Furthermore, in the present invention, there is no mechanical force that would cut the fibers, causing no damage to the fibers, and no deterioration in quality as in conventional methods. Moreover, the fibers are arranged almost perpendicularly to the mesh surface, forming a fiber group with good parallelism.
By capturing it as it is by moving the net,
It is possible to obtain a fiber bundle with excellent parallelism, and the bending of the fiber ends, that is, the hooked state can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing one embodiment of the apparatus of the present invention, FIG. 2 is a plan view showing another aspect of a part of the apparatus shown in FIG. 1, and FIG. 3 is an explanatory diagram of a conventional method.
FIG. 4 is a schematic perspective view showing an example of a conventional method. 11, 12... Net, 11a, 12a... Opposing mesh surfaces, 13, 14... Suction device, 15... Static electricity generator, 16... Grounding, 17... Fiber group supply device, 18... Conveyor belt , 19... Press belt, 20... Press belt, 21, 22
...Suction device.

Claims (1)

[Claims] 1. Applying high-voltage static electricity between opposing meshes and sucking from the back side of each mesh, a group of fibers is supplied between the meshes, and the fibers are arranged approximately perpendicular to the surface of the mesh. A short fiber removal method characterized by holding the short fibers in a vacuum and removing the short fibers by suction. 2. Two meshes facing each other with a predetermined interval between them, a static electricity generator that applies high-voltage static electricity between the meshes, a suction device disposed on the back side of the facing meshes, and a gap between the facing meshes. 1. A short fiber removal device comprising: a fiber group supply device provided on the side of the fiber group supply device;